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Sample records for cementless forged titanium

  1. Phased Array Ultrasonic Inspection of Titanium Forgings

    SciTech Connect

    Howard, P.; Klaassen, R.; Kurkcu, N.; Barshinger, J.; Chalek, C.; Nieters, E.; Sun, Zongqi; Fromont, F. de

    2007-03-21

    Aerospace forging inspections typically use multiple, subsurface-focused sound beams in combination with digital C-scan image acquisition and display. Traditionally, forging inspections have been implemented using multiple single element, fixed focused transducers. Recent advances in phased array technology have made it possible to perform an equivalent inspection using a single phased array transducer. General Electric has developed a system to perform titanium forging inspection based on medical phased array technology and advanced image processing techniques. The components of that system and system performance for titanium inspection will be discussed.

  2. Initial mechanical stability of cementless highly-porous titanium tibial components

    SciTech Connect

    Stone, Timothy Brandon; Amer, Luke D; Warren, Christopher P; Cornwell, Phillip; Meneghini, R Michael

    2008-01-01

    Cementless fixation in total knee replacement has seen limited use since reports of early failure surfaced in the late 80s and early 90s. However the emergence of improved biomaterials, particularly porous titanium and tantalum, has led to a renewed interest in developing a cementless tibial component to enhance long-term survivorship of the implants. Cement is commonly employed to minimize micromotion in new implants but represents a weak interface between the implant and bone. The elimination of cement and application of these new biomaterials, which theoretically provide improved stability and ultimate osseointegration, would likely result in greater knee replacement success. Additionally, the removal of cement from the procedure would help minimize surgical durations and get rid of the time needed for curing, thereby the chance of infection. The purpose of this biomechanical study was twofold. The first goal was to assess whether vibration analysis techniques can be used to evaluate and characterize initial mechanical stability of cementless implants more accurately than the traditional method of micromotion determination, which employs linear variable differential transducers (LVDTs). Second, an evaluative study was performed to determine the comparative mechanical stability of five designs of cementless tibial components under mechanical loading designed to simulate in vivo forces. The test groups will include a cemented Triathlon Keeled baseplate control group, three different 2-peg cementless baseplates with smooth, mid, and high roughnesses and a 4-peg cement/ess baseplate with mid-roughness.

  3. Microstructure development during conventional and isothermal hot forging of a near-gamma titanium aluminide

    SciTech Connect

    Semiatin, S.L. ); Seetharaman, V. ); Jain, V.K. . Mechanical and Aerospace Engineering Dept.)

    1994-12-01

    The breakdown of the lamellar preform microstructure in the ingot metallurgy near-gamma titanium aluminide, Ti-45.5Al-2Cr-2Nb (atomic percent), was investigated. Microstructures developed during canned, conventional hot forging were compared to those from isothermal hot forging. The higher rate of deformation in conventional forging led to considerably finer and almost completely broken-down structures in the as-forged condition. Several nontraditional approaches, including the isothermal forming of a metastable microstructure (so-called alpha forging'') and the inclusion of a short static recrystallization anneal during forging, were found to produce a more fully broken-down structure in as-isothermally forged conditions. Despite the noticeable microstructure differences after forging, a conventionally and isothermally forged material responded similarly during heat treatment. In both cases, almost totally recrystallized structures of either equiaxed gamma or transformed alpha grains surrounded by fine gamma grains were produced depending on the heat-treatment temperature. Metallography on forged and heat-treated pancake macroslices was useful in delineating small differences in composition not easily detected by analytical methods.

  4. Effect of Variants of Thermomechanical Working and Annealing Treatment on Titanium Alloy Ti6Al4V Closed Die Forgings

    NASA Astrophysics Data System (ADS)

    Gupta, R. K.; Kumar, V. Anil; Kumar, P. Ram

    2016-06-01

    Performance of titanium alloy Ti6Al4V pressure vessels made of closed die forged domes of route `B' (multiple step forged and mill annealed) is reported to be better than route `A' (single/two step forged and mill annealed). Analysis revealed that forgings processed through route `B' have uniformity in microstructure and yield strength at various locations within the forging, as compared to that of route `A.' It is attributed to in-process recrystallization (dynamic as well as static) of route `B' forgings as compared to limited recrystallization of route `A' forgings. Further, post-forging recrystallization annealing (RA) effect is found to be more significant for route `A' forgings in achieving uniform microstructure and mechanical properties, since route `B' forgings have already undergone similar phenomenon during the thermomechanical working process itself. Considering prime importance of yield strength, statistical scatter in yield strength values within the forgings have been evaluated for forgings of both the routes. Standard deviation in the yield strength of route `B' forgings was lower (<10 MPa) as compared to route `A' (>15 MPa), which later became lower (~10 MPa) after RA with a minor decrease in yield strength. The present work discusses these variants of thermomechanical processing along with annealing to achieve better uniformity in properties and microstructure.

  5. Phased Array Inspection of Titanium Disk Forgings Targeting no. 1/2 FBH Sensitivity

    SciTech Connect

    Roberts, R.A.; Friedl, J.

    2005-04-09

    The phased array implementation of a focused zoned ultrasonic inspection to achieve a >3dB signal-to-noise for no. 1/2 flat bottom holes (FBH) in titanium is reported. Previous work established the ultrasound focusing required to achieve the targeted sensitivity. This work reports on the design of a phased array transducer capable of maintaining the needed focus to the depths required in the forging inspection. The performance of the phased array inspection is verified by examining signal-to-noise of no. 1/2 FBHs contained in coupons cut from actual forgings.

  6. A new cementless total hip arthroplasty with bioactive titanium porous-coating by alkaline and heat treatment: average 4.8-year results.

    PubMed

    Kawanabe, Keiichi; Ise, Kentaro; Goto, Koji; Akiyama, Haruhiko; Nakamura, Takashi; Kaneuji, Ayumi; Sugimori, Tanzo; Matsumoto, Tadami

    2009-07-01

    A method has been developed for creating a bioactive coating on titanium by alkaline and heat treatment, and shown that it forms a thin layer of hydroxyapatite (HA) on the surface of implants when soaked in simulated body fluid. A series of 70 cementless primary total hip arthroplasties using this coating technique on a porous titanium surface was performed, and followed up the patients for a mean period of 4.8 years. There were no instances of loosening or revision, or formation of a reactive line on the porous coating. Although radiography just after operation showed a gap between the host bone and the socket in over 70% of cases, all the gaps disappeared within a year, indicating the good osteoconduction provided by the coating. Alkaline-heat treatment of titanium to provide a thin HA coating has several advantages over plasma-spraying, including no degeneration or absorption of the HA coating, simplicity of the manufacturing process, and cost effectiveness. In addition, this method allows homogeneous deposition of bone-like apatite within a porous implant. Although this was a relatively short-term study, treatment that creates a bioactive surface on titanium and titanium alloy implants has considerable promise for clinical application.

  7. Forging And Milling Contribution On Residual Stresses For A Textured Biphasic Titanium Alloy

    SciTech Connect

    Deleuze, C.; Fabre, A.; Barrallier, L.; Molinas, O.

    2011-01-17

    Ti-10V-2Fe-3Al is a biphasic titanium alloy ({alpha}+{beta}) used in aeronautical applications for its mechanical properties, such as its yield strength of 1200 MPa and it weighs 40% less than steel. This alloy is particularly useful for vital parts with complex geometry, because of its high forging capability. In order to predict the capability for fatigue lifetime, the designers need to know the residual stresses. X-Ray diffraction is the main experimental technique used to determine residual stresses on the surface. In this case, stress levels are primarily influenced by the complex forging and milling process. On this alloy in particular, it may be difficult to characterize stress due to modification of the microstructure close to the surface. Results obtained by x-ray analysis depend on the correct definition of the shape of the diffraction peaks. The more precisely defined the position of the peak, the more accurately the stresses are evaluated. This paper presents a method to detect if residual stresses can be characterized by x-ray diffraction. The characterization of hardness seems to be a relevant technique to quickly analyze the capability of x-ray diffraction to determine residual stresses.

  8. Pod of Ultrasonic Detection of Synthetic Hard Alpha Inclusions in Titanium Aircraft Engine Forgings

    NASA Astrophysics Data System (ADS)

    Thompson, R. B.; Meeker, W. Q.; Brasche, L. J. H.

    2011-06-01

    The probability of detection (POD) of inspection techniques is a key input to estimating the lives of structural components such as aircraft engines. This paper describes work conducted as a part of the development of POD curves for the ultrasonic detection of synthetic hard alpha (SHA) inclusions in titanium aircraft engine forgings. The sample upon which the POD curves are to be based contains four types of right circular SHAs that have been embedded in a representative titanium forging, as well as a number of flat bottomed holes (FBHs). The SHAs were of two sizes, ♯3 and ♯5, with each size including seeds with nominal nitrogen concentrations of both 3 and 17 wt. %. The FBHs included sizes of ♯1, ♯3, and ♯5. This discreteness of the data poses a number of challenges to standard processes for determining POD. For example, at each concentration of nitrogen, there are only two sizes, with 10 inspection opportunities each. Fully empirical, standard methodologies such as â versus a provide less than an ideal framework for such an analysis. For example, there is no way to describe the beam limiting effect whereby the signal no longer increases the flaw grows larger than the beam, one can only determine POD at the two concentration levels present in the block, and confidence bounds tend to be broad because of the limited data available for each case. In this paper, we will describe strategies involving the use of physics-based models to overcome these difficulties by allowing the data from all reflectors to be analyzed by a single statistical model. Included will be a discussion of the development of the physics-based model, its comparison to the experimental data (obtained at multiple sites with multiple operators) and its implications regarding the statistical analysis, whose details will be given in a separate article by Li et al. in this volume.

  9. Hydroxyapatite in total hip arthroplasty. Our experience with a plasma spray porous titanium alloy/hydroxyapatite double-coated cementless stem

    PubMed Central

    Castellini, Iacopo; Andreani, Lorenzo; Parchi, Paolo Domenico; Bonicoli, Enrico; Piolanti, Nicola; Risoli, Francesca; Lisanti, Michele

    2016-01-01

    Summary Purpose Total hip arthroplasty could fail due to many factors and one of the most common is the aseptic loosening. In order to achieve an effective osseointegration and reduce risk of lossening, the use of cemented implant, contact porous bearing surface and organic coating were developed. Aim of this study was to evaluate clinical and radiological mid-term outcomes of a porous titanium alloy/hydroxyapatite double coating manufactured cementless femoral stem applied with “plasma spray” technique and to demonstrate the possibility to use this stem in different types of femoral canals. Methods Between January 2008 and December 2012, 240 consecutive primary total hip arthroplasties (THAs) were performed using a porous titanium alloy/hydroxyapatite double coating manufactured cementless femoral stem. 182 patients were examined: 136 were females (74.7%) and 46 males (25.2%); average age was 72 years old (ranging from 26 to 92 years old). For each patient, Harris Hip Scores (HHS) and Womac Scores were collected. All X-ray images were analyzed in order to demonstrate stem survival rate and subsidence. Results Harris Hip Score was good or excellent in 85% of the cases (average 90%) and mean WOMAC score was 97.5 (ranging from 73.4 to 100). No cases of early/late infection or periprosthetic fracture were noticed, with an excellent implant survival rate (100%) in a mean period of 40 months (ranging from 24 and 84 months). 5 cases presented acute implant dislocation, 2 due to wrong cup positioning in a dysplastic acetabulum and 3 after ground level fall. Dorr classification of femoral geometry was uses and the results were: 51 type A bone, 53 type B bone and 78 type C bone. Stem subsidence over 2 mm was considered as a risk factor of future implant loosening and was evidenced in 3 female patients with type C of Dorr classification. No radiolucencies signs around the proximally coated portion of stem or proximal reabsorption were visible during the radiographic

  10. Comparison of cementless and hybrid cemented total knee arthroplasty.

    PubMed

    Lass, Richard; Kubista, Bernd; Holinka, Johannes; Pfeiffer, Martin; Schuller, Spiro; Stenicka, Sandra; Windhager, Reinhard; Giurea, Alexander

    2013-04-01

    Cementless total knee arthroplasty (TKA) implants were designed to provide long-term fixation without the risk of cement-associated complications. The purpose of this study was to evaluate the outcome of titanium-coated cementless implants compared with hybrid TKA implants with a cemented tibial and a cementless femoral component. The authors performed a case-control, single-center study of 120 TKAs performed between 2003 and 2007, including 60 cementless and 60 hybrid cemented TKAs. The authors prospectively analyzed the radiographic and clinical data and the survivorship of the implants at a minimum follow-up of 5 years. Ninety patients who underwent TKA completed the 5-year assessment. Knee Society Scores increased significantly in both groups (P<.001). In both groups, 2 patients underwent revision due to aseptic tibial component loosening, resulting in a 96% implant survival rate. Radiographs showed significantly less radiolucent lines around the tibial baseplate in the cementless group (n=12) than in the hybrid cemented group (n=26) (P=.009).At 6-year mean follow-up, no significant difference existed between the cementless and hybrid cemented tibial components in TKA in terms of clinical and functional results and postoperative complications. The significantly smaller number of radiolucent lines in the cementless group is an indicator of primary stability with the benefit of long-term fixation durability of TKA.

  11. Development of {gamma}+{alpha}{sub 2}+B2 type titanium aluminide for forged turbine rotors

    SciTech Connect

    Tetsui, Toshimitsu

    1995-12-31

    In order to apply TiAl for forged turbine rotors, hot deformability at manufacturing process and high temperature strength at application are both required. For these requirements a new {gamma}+{alpha}{sub 2}+B2 type TiAl (named KAT-3) has been developed. The alloy composition is Ti-45Al-8Nb-2Cr (at%) and this alloy consists of three phases: {gamma}, {alpha}{sub 2} and B2. Because B2 phase has excellent hot deformability and {gamma}/{alpha}{sub 2} lamellar structure has excellent high temperature strength, the above contradictory requirements for TiAl can both be achieved by optimizing the manufacturing process. In this paper various properties required for turbine rotor materials of this alloy were investigated, especially in comparison with Inconel 713C.

  12. Manufacturing of Precision Forgings by Radial Forging

    NASA Astrophysics Data System (ADS)

    Wallner, S.; Harrer, O.; Buchmayr, B.; Hofer, F.

    2011-01-01

    Radial forging is a multi purpose incremental forging process using four tools on the same plane. It is widely used for the forming of tool steels, super alloys as well as titanium- and refractory metals. The range of application goes from reducing the diameters of shafts, tubes, stepped shafts and axels, as well as for creating internal profiles for tubes in Near-Net-Shape and Net-Shape quality. Based on actual development of a weight optimized transmission input shaft, the specific features of radial forging technology is demonstrated. Also a Finite Element Model for the simulation of the process is shown which leads to reduced pre-processing effort and reduced computing time compared to other published simulation methods for radial forging. The finite element model can be applied to quantify the effects of different forging strategies.

  13. Cementless acetabular revision arthroplasty

    PubMed Central

    Jain, Rina; Schemitsch, Emil H.; Waddell, James P.

    2000-01-01

    Objective To evaluate the effects of clinical factors on outcome after acetabular revision with a cementless beaded cup. Design Retrospective case series. Setting Tertiary care referral centre. Patients Forty-one patients who underwent acetabular revision with a cementless cup were followed up for a mean of 3.4 years. Interventions Acetabular revision with a beaded cementless cup in all patients. A morcellized allograft was used in 10 patients. Outcome measures A modified Harris hip score (range of motion measurement omitted), the SF-36 health survey, and the Western Ontario McMaster (WOMAC) osteoarthritis index. Multivariate analysis was used to evaluate the effects of age, gender, morcellized allografting, time to revision from the previous operation, acetabular screw fixation and concurrent femoral revision on outcome. Results Gender accounted for a significant portion of the variation seen in the SF-36 physical component scores (r = 0.36, p = 0.02), with women tending to have worse results. Increasing age was associated with lower WOMAC index function scores (r = 0.36, p = 0.03), whereas concurrent femoral revision tended to have a positive effect on WOMAC index function (r = 0.39, p = 0.01). None of the potential clinical predictors had any significant effect on the SF-36 mental component scores, or WOMAC index pain and stiffness scores. Conclusions In cementless acetabular revision arthroplasty, physical function, as measured by generic and limb-specific scales, may be affected by gender, age and the presence of a concurrent femoral revision. Time to revision from the previous operation, morcellized allografting and screw fixation of the acetabulum did not affect outcomes. This information may provide some prognostic value for patients’ expectations. PMID:10948687

  14. Effect of hot-forging on beta phase transformation of a high niobium containing titanium aluminide alloy

    NASA Astrophysics Data System (ADS)

    Cheng, Liang; Xue, Xiangyi; Tang, Bin; Kou, Hongchao; Li, Jinshan

    2015-03-01

    In this paper, ingot breakdown process of a high Nb containing TiAl alloy with a chemical composition of Ti-42.63Al-8.11Nb-0.21W-0.09Y (at.%) has been investigated under conventional forging conditions. It was found that the present alloy possesses superior hot-workability that can be successfully forged by conventional upsetting route due to the appearance of large amount of β/B2 phase, though shear band was observed in the forged-pancake. Further studies revealed that hot-working performed in (α + β) phase region which can effectively impede the β → α transformation and thus significantly increase the volume fraction of β/B2 phase. In contrast, the amount of β/B2 phase was notably reduced by heat treatment at the same conditions. This stress-induced effect is considered to be responsible to the superior hot-workability of the present alloy and the mechanism has been discussed and reasonably clarified. It was also suggested that the stress-induced effect has practical significance that it allows the implementation of conventional multi-step forging process which can develop fine and uniform microstructures suitable for secondary processing.

  15. Cementless Hydroxyapatite Coated Hip Prostheses

    PubMed Central

    Herrera, Antonio; Mateo, Jesús; Gil-Albarova, Jorge; Lobo-Escolar, Antonio; Ibarz, Elena; Gabarre, Sergio; Más, Yolanda

    2015-01-01

    More than twenty years ago, hydroxyapatite (HA), calcium phosphate ceramics, was introduced as a coating for cementless hip prostheses. The choice of this ceramic is due to its composition being similar to organic apatite bone crystals. This ceramic is biocompatible, bioactive, and osteoconductive. These qualities facilitate the primary stability and osseointegration of implants. Our surgical experience includes the implantation of more than 4,000 cementless hydroxyapatite coated hip prostheses since 1990. The models implanted are coated with HA in the acetabulum and in the metaphyseal area of the stem. The results corresponding to survival and stability of implants were very satisfactory in the long-term. From our experience, HA-coated hip implants are a reliable alternative which can achieve long term survival, provided that certain requirements are met: good design selection, sound choice of bearing surfaces based on patient life expectancy, meticulous surgical technique, and indications based on adequate bone quality. PMID:25802848

  16. Implant Design in Cementless Hip Arthroplasty

    PubMed Central

    Kim, Jung Taek

    2016-01-01

    When performing cementless hip arthroplasty, it is critical to achieve firm primary mechanical stability followed by biological fixation. In order to achieve this, it is essential to fully understand characteristics of implant design. In this review, the authors review fixation principles for a variety of implants used for cementless hip replacement and considerations for making an optimal selection. PMID:27536647

  17. Forging Advisor

    SciTech Connect

    Kerry Barnett

    2003-03-01

    Many mechanical designs demand components produced to a near net shape condition to minimize subsequent process steps. Rough machining from slab or bar stock can quickly and economically produce simple prismatic or cylindrical shapes. More complex shapes can be produced by laser engineered net shaping (LENS), casting , or forging. But for components that require great strength in mission critical applications, forging may be the best or even the only option. However, designers of these parts may and often do lack the detailed forging process knowledge necessary to understand the impact of process details such as grain flow or parting line placement on both the forging process and the characteristics of the forged part. Economics and scheduling requirements must also be considered. Sometimes the only viable answer to a difficult problem is to re-design the assembly to reduce loading and enable use of other alternatives.

  18. Unicondylar knee arthroplasty: a cementless perspective

    PubMed Central

    Forsythe, Michael E.; Englund, Roy E.; Leighton, Ross K.

    2000-01-01

    Objective To compare the results of cementless unicondylar knee arthroplasty (UKA) with those already reported in a similar study on cemented UKA. Design A case-series cross-sectional study. Setting The Queen Elizabeth II Health Sciences Centre, Dalhousie University, Halifax. Patients Fifty-one patients who underwent a total of 57 UKAs between May 1989 and May 1997. Inclusion criteria were osteoarthritis involving the predominantly the medial compartment of the knee, relative sparing of the other compartments, less than 15° of varus, minimal knee instability, and attendance at the postoperative clinical visit. Intervention Cementless UKA. Main outcome measures Clinical parameters that included pain, range of motion and the Knee Society Clinical Knee Score. Roentgenographic parameters that included α, β, γ and σ angles and the presence of periprosthetic radiolucency or loose beads. Results Age, weight, gender and follow-up interval did not significantly affect the clinical results in terms of pain, range of motion or knee score. Knees with more than 1 mm of radiolucency had significantly lower knee scores than those with no radiolucency. Knees that radiologically had loose beads also had significantly lower knee scores. The clinical outcomes of cementless UKA were comparable to those already reported on cemented UKA. Cementless femurs had less radiolucency than the cemented femurs, whereas cementless tibias had more radiolucency than their cemented counterparts. Conclusions Cementless UKA seems to be as efficacious as cemented UKA. However, there is some concern about the amount of radiolucency in the cementless tibial components. A randomized clinical trial comparing both cementless and cemented tibial components with a cementless femur (hybrid knee) is needed to further assess this controversial issue in UKA. PMID:11129829

  19. Cemented and cementless fixation: results and techniques.

    PubMed

    Silverton, Craig D

    2006-01-01

    There are multiple reports of successful cemented and cementless total knee arthroplasty in the current literature. Although technically more demanding to implant, selected cementless designs, with nearly 20 years of follow-up, demonstrate near-equal success compared with cemented implants, the gold standard. Far more important than the decision to use a cemented or cementless implant is the use of precise technique, adequate balancing of the soft tissues, and proper overall alignment. Failure to achieve these basic principles can lead to early failure in any total knee replacement system.

  20. New Trends in Forging Technologies

    NASA Astrophysics Data System (ADS)

    Behrens, B.-A.; Hagen, T.; Knigge, J.; Elgaly, I.; Hadifi, T.; Bouguecha, A.

    2011-05-01

    Limited natural resources increase the demand on highly efficient machinery and transportation means. New energy-saving mobility concepts call for design optimisation through downsizing of components and choice of corrosion resistant materials possessing high strength to density ratios. Component downsizing can be performed either by constructive structural optimisation or by substituting heavy materials with lighter high-strength ones. In this context, forging plays an important role in manufacturing load-optimised structural components. At the Institute of Metal Forming and Metal-Forming Machines (IFUM) various innovative forging technologies have been developed. With regard to structural optimisation, different strategies for localised reinforcement of components were investigated. Locally induced strain hardening by means of cold forging under a superimposed hydrostatic pressure could be realised. In addition, controlled martensitic zones could be created through forming induced phase conversion in metastable austenitic steels. Other research focused on the replacement of heavy steel parts with high-strength nonferrous alloys or hybrid material compounds. Several forging processes of magnesium, aluminium and titanium alloys for different aeronautical and automotive applications were developed. The whole process chain from material characterisation via simulation-based process design to the production of the parts has been considered. The feasibility of forging complex shaped geometries using these alloys was confirmed. In spite of the difficulties encountered due to machine noise and high temperature, acoustic emission (AE) technique has been successfully applied for online monitoring of forging defects. New AE analysis algorithm has been developed, so that different signal patterns due to various events such as product/die cracking or die wear could be detected and classified. Further, the feasibility of the mentioned forging technologies was proven by means

  1. Titanium

    SciTech Connect

    Fox, G.J.

    1997-01-01

    The article contains a summary of factors pertinent to titanium use. Geology and exploitation, production processes, global production, titanium dioxide and alloy applications, and the titanium market are reviewed. Potential applications outlined are for oil and gas equipment and for the automotive industry. Titanium alloys were selected for drilling risers for North Sea oil and gas drilling platforms due to a high strength-to-weight ratio and corrosion resistance. These properties also make titanium alloys attractive for auto parts, although the cost is currently prohibitive.

  2. Titanium

    USGS Publications Warehouse

    Bedinger, G.M.

    2013-01-01

    Titanium is the ninth most abundant element in the earth’s crust and can be found in nearly all rocks and sediments. It is a lithophile element with a strong affinity for oxygen and is not found as a pure metal in nature. Titanium was first isolated as a pure metal in 1910, but it was not until 1948 that metal was produced commercially using the Kroll process (named after its developer, William Kroll) to reduce titanium tetrachloride with magnesium to produce titanium metal.

  3. HYDRODYNAMIC COMPRESSIVE FORGING.

    DTIC Science & Technology

    HYDRODYNAMICS), (*FORGING, COMPRESSIVE PROPERTIES, LUBRICANTS, PERFORMANCE(ENGINEERING), DIES, TENSILE PROPERTIES, MOLYBDENUM ALLOYS , STRAIN...MECHANICS), BERYLLIUM ALLOYS , NICKEL ALLOYS , CASTING ALLOYS , PRESSURE, FAILURE(MECHANICS).

  4. Antibacterial efficacy of a new gentamicin-coating for cementless prostheses compared to gentamicin-loaded bone cement.

    PubMed

    Neut, Daniëlle; Dijkstra, René J B; Thompson, Jonathan I; van der Mei, Henny C; Busscher, Henk J

    2011-11-01

    Cementless prostheses are increasingly popular but require alternative prophylactic measures than the use of antibiotic-loaded bone cements. Here, we determine the 24-h growth inhibition of gentamicin-releasing coatings from grit-blasted and porous-coated titanium alloys, and compare their antibacterial efficacies and gentamicin release-profiles to those of a commercially available gentamicin-loaded bone cement. Antibacterial efficacy increased with increasing doses of gentamicin in the coating and loading with 1.0 and 0.1 mg gentamicin/cm(2) on both grit-blasted and porous-coated samples yielded comparable efficacy to gentamicin-loaded bone cement. The coating had a higher burst release than bone cement, and also inhibited growth of gentamicin-resistant strains. Antibacterial efficacy of the gentamicin coatings disappeared after 4 days, while gentamicin-loaded bone cement exhibited efficacy over at least 7 days. Shut-down after 4 days of gentamicin-release from coatings is advantageous over the low-dosage tail-release from bone cements, as it minimizing risk of inducing antibiotic-resistant strains. Both gentamicin-loaded cement discs and gentamicin-coated titanium coupons were able to kill gentamicin-sensitive and -resistant bacteria in a simulated prothesis-related interfacial gap. In conclusion, the gentamicin coating provided similar antibacterial properties to those seen by gentamicin-loaded bone cement, implying protection of a prosthesis from being colonized by peri-operatively introduced bacteria in cementless total joint arthroplasty.

  5. A gentamicin-releasing coating for cementless hip prostheses-Longitudinal evaluation of efficacy using in vitro bio-optical imaging and its wide-spectrum antibacterial efficacy.

    PubMed

    Neut, Daniëlle; Dijkstra, René J B; Thompson, Jonathan I; van der Mei, Henny C; Busscher, Henk J

    2012-12-01

    Cementless prostheses are increasingly popular in total hip arthroplasties. Therewith, common prophylactic measures to reduce the risk of postoperative infection like the use of antibiotic-loaded bone cements, will no longer be available. Alternative prophylactic measures may include the use of antibiotic-releasing coatings. Previously, we developed a gentamicin-releasing coating for cementless titanium hip prostheses and derived an appropriate dosing of this coating by adjusting the amount of gentamicin in the coating to match the antibacterial efficacy of clinically employed gentamicin-loaded bone cement. In this manuscript, we investigated two important issues regarding the prophylactic use of this 1 mg cm(-2) bioactive gentamicin-releasing coating in cementless total hip arthroplasty: (1) its ability to prevent bacterial growth in a geometrically relevant set-up and (2) its antibacterial spectrum. A geometrically relevant set-up was developed in which miniature titanium stems were surrounded by agar, contaminated with bioluminescent Staphylococcus aureus. Novel, bio-optical imaging was performed allowing noninvasive, longitudinal monitoring of staphylococcal growth around miniature stems with and without the gentamicin-releasing coating. Furthermore, the antibacterial efficacy of the gentamicin-releasing coating was determined against a wide variety of clinical isolates, including bioluminescent Staphylococcus aureus strains, using traditional zone of inhibition measurements. The gentamicin-releasing coating demonstrated a wide-spectrum of antibacterial efficacy and successfully prevented growth of bioluminescent staphylococci around a miniature stem mounted in bacterially contaminated agar for at least 60 h. This implies that the gentamicin-releasing coating has potential to contribute to the improvement of infection prophylaxis in cementless total hip arthroplasty.

  6. Forging Long Shafts On Disks

    NASA Technical Reports Server (NTRS)

    Tilghman, Chris; Askey, William; Hopkins, Steven

    1989-01-01

    Isothermal-forging apparatus produces long shafts integral with disks. Equipment based on modification of conventional isothermal-forging equipment, required stroke cut by more than half. Enables forging of shafts as long as 48 in. (122 cm) on typical modified conventional forging press, otherwise limited to making shafts no longer than 18 in. (46cm). Removable punch, in which forged material cools after plastic deformation, essential novel feature of forging apparatus. Technology used to improve such products as components of gas turbines and turbopumps and of other shaft/disk parts for powerplants, drive trains, or static structures.

  7. Deformation processes in forging ceramics

    NASA Technical Reports Server (NTRS)

    Cannon, R. M.; Rhodes, W. H.

    1972-01-01

    The deformation processes involved in the forging of refractory ceramic oxides were investigated. A combination of mechanical testing and forging are utilized to investigate both the flow and fracture processes involved. An additional hemisphere forging was done which failed prematurely. Analysis and comparison with available fracture data for AL2O3 indicated possible causes of the failure. Examination of previous forgings indicated an increase in grain boundary cavitation with increasing strain.

  8. Modeling of Closed-Die Forging for Estimating Forging Load

    NASA Astrophysics Data System (ADS)

    Sheth, Debashish; Das, Santanu; Chatterjee, Avik; Bhattacharya, Anirban

    2017-02-01

    Closed die forging is one common metal forming process used for making a range of products. Enough load is to exert on the billet for deforming the material. This forging load is dependent on work material property and frictional characteristics of the work material with the punch and die. Several researchers worked on estimation of forging load for specific products under different process variables. Experimental data on deformation resistance and friction were used to calculate the load. In this work, theoretical estimation of forging load is made to compare this value with that obtained through LS-DYNA model facilitating the finite element analysis. Theoretical work uses slab method to assess forging load for an axi-symmetric upsetting job made of lead. Theoretical forging load estimate shows slightly higher value than the experimental one; however, simulation shows quite close matching with experimental forging load, indicating possibility of wide use of this simulation software.

  9. Partners: Forging Strong Relationships.

    ERIC Educational Resources Information Center

    Spears, Ellen, Ed.

    1999-01-01

    This newsletter issue asserts that sound, effective relationships in which diverse groups of people and organizations work together toward a common goal are the basis of the collaborative efforts in education that can accomplish change. The first article, "Partners: Forging Strong Relationships" (Sarah E. Torian), briefly describes the…

  10. Fallon FORGE Well Lithologies

    SciTech Connect

    Doug Blankenship

    2016-03-01

    x,y,z text file of the downhole lithologic interpretations in the wells in and around the Fallon FORGE site. All the relevant information is in the file header (the spatial reference, the projection etc.) In addition all the fields in the data file are identified in the header.

  11. Intraoperative Proximal Femoral Fracture in Primary Cementless Total Hip Arthroplasty.

    PubMed

    Ponzio, Danielle Y; Shahi, Alisina; Park, Andrew G; Purtill, James J

    2015-08-01

    Intraoperative proximal femoral fracture is a complication of primary cementless total hip arthroplasty (THA) at rates of 2.95-27.8%. A retrospective review of 2423 consecutive primary cementless THA cases identified 102 hips (96 patients) with fracture. Multivariate analysis compared fracture incidences between implants, Accolade (Stryker Orthopaedics) and Tri-Lock (DePuy Orthopaedics, Inc.), and evaluated potential risk factors using a randomized control group of 1150 cases without fracture. The fracture incidence was 4.4% (102/2423), 3.7% (36/1019) using Accolade and 4.9% using Tri-Lock (66/1404) (P=0.18). Female gender (OR=1.96; 95% CI 1.19-3.23; P=0.008) and smaller stem size (OR=1.64; 95% CI 1.04-2.63; P=0.03) predicted increased odds of fracture. No revisions of the femoral component were required in the fracture cohort.

  12. Superplastic forging nitride ceramics

    DOEpatents

    Panda, Prakash C.; Seydel, Edgar R.; Raj, Rishi

    1988-03-22

    The invention relates to producing relatively flaw free silicon nitride ceramic shapes requiring little or no machining by superplastic forging This invention herein was made in part under Department of Energy Grant DE-AC01-84ER80167, creating certain rights in the United States Government. The invention was also made in part under New York State Science and Technology Grant SB1R 1985-10.

  13. Method of making multilayered titanium ceramic composites

    DOEpatents

    Fisher, II, George T.; Hansen, Jeffrey S.; Oden, Laurance L.; Turner, Paul C.; Ochs, Thomas L.

    1998-01-01

    A method making a titanium ceramic composite involves forming a hot pressed powder body having a microstructure comprising at least one titanium metal or alloy layer and at least one ceramic particulate reinforced titanium metal or alloy layer and hot forging the hot pressed body follwed by hot rolling to substantially reduce a thickness dimension and substantially increase a lateral dimension thereof to form a composite plate or sheet that retains in the microstructure at least one titanium based layer and at least one ceramic reinforced titanium based layer in the thickness direction of the composite plate or sheet.

  14. Method of making multilayered titanium ceramic composites

    DOEpatents

    Fisher, G.T. II; Hansen, J.S.; Oden, L.L.; Turner, P.C.; Ochs, T.L.

    1998-08-25

    A method making a titanium ceramic composite involves forming a hot pressed powder body having a microstructure comprising at least one titanium metal or alloy layer and at least one ceramic particulate reinforced titanium metal or alloy layer and hot forging the hot pressed body followed by hot rolling to substantially reduce a thickness dimension and substantially increase a lateral dimension thereof to form a composite plate or sheet that retains in the microstructure at least one titanium based layer and at least one ceramic reinforced titanium based layer in the thickness direction of the composite plate or sheet. 3 figs.

  15. Method of making multilayered titanium ceramic composites

    DOEpatents

    Fisher, George T., II; Hansen; Jeffrey S.; Oden; Laurance L.; Turner; Paul C.; Ochs; Thomas L.

    1998-08-25

    A method making a titanium ceramic composite involves forming a hot pressed powder body having a microstructure comprising at least one titanium metal or alloy layer and at least one ceramic particulate reinforced titanium metal or alloy layer and hot forging the hot pressed body follwed by hot rolling to substantially reduce a thickness dimension and substantially increase a lateral dimension thereof to form a composite plate or sheet that retains in the microstructure at least one titanium based layer and at least one ceramic reinforced titanium based layer in the thickness direction of the composite plate or sheet.

  16. Superplastic forging nitride ceramics

    DOEpatents

    Panda, P.C.; Seydel, E.R.; Raj, R.

    1988-03-22

    A process is disclosed for preparing silicon nitride ceramic parts which are relatively flaw free and which need little or no machining, said process comprising the steps of: (a) preparing a starting powder by wet or dry mixing ingredients comprising by weight from about 70% to about 99% silicon nitride, from about 1% to about 30% of liquid phase forming additive and from 1% to about 7% free silicon; (b) cold pressing to obtain a preform of green density ranging from about 30% to about 75% of theoretical density; (c) sintering at atmospheric pressure in a nitrogen atmosphere at a temperature ranging from about 1,400 C to about 2,200 C to obtain a density which ranges from about 50% to about 100% of theoretical density and which is higher than said preform green density, and (d) press forging workpiece resulting from step (c) by isothermally uniaxially pressing said workpiece in an open die without initial contact between said workpiece and die wall perpendicular to the direction of pressing and so that pressed workpiece does not contact die wall perpendicular to the direction of pressing, to substantially final shape in a nitrogen atmosphere utilizing a temperature within the range of from about 1,400 C to essentially 1,750 C and strain rate within the range of about 10[sup [minus]7] to about 10[sup [minus]1] seconds[sup [minus]1], the temperature and strain rate being such that surface cracks do not occur, said pressing being carried out to obtain a shear deformation greater than 30% whereby superplastic forging is effected.

  17. Nonconforming Titanium Task Force Actions to Resolve Aircraft Safety Issues due to Improperly Substituted Material

    DTIC Science & Technology

    2012-06-21

    plate • AMS-T-9047 Bar • Extrusions • Die Forgings • Rod • Wire Hot Rolling • AMS-T-9046 sheet and strip • Heating • Forging • Cooling Ingots...plate • AMS-T-9047 Bar • Extrusions • Die Forgings • Rod • Wire Hot Rolling • AMS-T-9046 sheet and strip 29 Titanium plate and sheet is...Reforging Stock Hot Rolling Hot Forging/ Rolling High Deformation Processes • AMS-T-9046 plate • AMS-T-9047 Bar • Extrusions • Die Forgings • Rod

  18. Immediate Cementless Hemiarthroplasty for Severe Destructive Glenohumeral Tuberculous Arthritis

    PubMed Central

    Kosiyatrakul, Arkaphat

    2013-01-01

    The glenohumeral joint tuberculosis (TB) is rare as compared with other joints. Plaster immobilization, arthrodesis, and resection arthroplasty have been proposed as the additional treatments with anti-TB medications in severe destructive arthritis. To our knowledge, however, the surgical treatment with shoulder arthroplasty has never been reported. We present two cases of active TB with unsalvageable glenohumeral joint. The cementless hemishoulder arthroplasties were performed immediately following the radical debridement. Anti-TB medications were given for 12 months after the surgery. Postoperatively, the patients were satisfied with the rapid symptomatic relief and significant functional recovery. With the follow-up period of 5 years, the operative results were still satisfactory and the reactivation of the infection was not detected. PMID:24167752

  19. Large forging manufacturing process

    DOEpatents

    Thamboo, Samuel V.; Yang, Ling

    2002-01-01

    A process for forging large components of Alloy 718 material so that the components do not exhibit abnormal grain growth includes the steps of: a) providing a billet with an average grain size between ASTM 0 and ASTM 3; b) heating the billet to a temperature of between 1750.degree. F. and 1800.degree. F.; c) upsetting the billet to obtain a component part with a minimum strain of 0.125 in at least selected areas of the part; d) reheating the component part to a temperature between 1750.degree. F. and 1800.degree. F.; e) upsetting the component part to a final configuration such that said selected areas receive no strains between 0.01 and 0.125; f) solution treating the component part at a temperature of between 1725.degree. F. and 1750.degree. F.; and g) aging the component part over predetermined times at different temperatures. A modified process achieves abnormal grain growth in selected areas of a component where desirable.

  20. Pilot Plant Forging of Hydrogenated Ti-6Al-4V.

    DTIC Science & Technology

    1980-06-01

    inserted into an M-246 nickel base superalloy die block with 713C alloy flat dies positioned on the heated die block. The entire die system was enclosed...side if neceaary and identify by block number) Hydrogenation Isothermal Forging Ring Test Titanium Alloy Ti-6A1-4V Flow Stress 20. k9Sr9Xd1’ (Continue on...5 Rack used to hold Specimens during Hydrogenation 29 6 Flow Stress-Plastic Strain Relation for Ti-6AI-4V Alloy (Heat A) with Various Hydrogen

  1. 29 CFR 1910.218 - Forging machines.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 5 2014-07-01 2014-07-01 false Forging machines. 1910.218 Section 1910.218 Labor... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Machinery and Machine Guarding § 1910.218 Forging machines. (a... other identifier, for the forging machine which was inspected. (ii) Scheduling and recording...

  2. 29 CFR 1910.218 - Forging machines.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 5 2013-07-01 2013-07-01 false Forging machines. 1910.218 Section 1910.218 Labor... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Machinery and Machine Guarding § 1910.218 Forging machines. (a... other identifier, for the forging machine which was inspected. (ii) Scheduling and recording...

  3. 29 CFR 1910.218 - Forging machines.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 5 2011-07-01 2011-07-01 false Forging machines. 1910.218 Section 1910.218 Labor... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Machinery and Machine Guarding § 1910.218 Forging machines. (a... other identifier, for the forging machine which was inspected. (ii) Scheduling and recording...

  4. Thermal-mechanical processing of a 48-2-2 {gamma}-titanium aluminide

    SciTech Connect

    Davey, S.; Loretto, M.H.; Dean, T.A.; Huang, Z.W.; Blenkinsop, P.; Evans, R.W.; Jones, A.

    1995-12-31

    The paper describes the hot working behavior of a cast 48-2-2 titanium aluminide. Constant strain rate isothermal forging tests have been conducted over the temperature range 900 C to 1,220 C and at strain rates between 0.0001s{sup {minus}1} and 50s{sup {minus}1}. A forging regime, in terms of temperature and strain rate, exists which allows large strain hot forging to be carried out with the production of sound forgings. In addition considerable microstructure refinement is achieved through dynamic recrystallization. Constitutive relationships for deformation and for microstructural evolution have been derived. Larger scale forgings have been carried out isothermally and have been used to establish that the relationships are applicable to the hot forging of TiAl under conditions likely to be met in industrial forging operations.

  5. Powder Metallurgy Forged Gear Development

    DTIC Science & Technology

    1985-03-01

    Unclassified) 12. PERSONAL AUTHOR(S) D. H. Ro, B. L. Ferguson, S. Pillay, D. T. Ostberg 13a. TYPE OF REPORT 13b. TIME COVERED 14. DATE OF REPORT (Year, Month...Method Water Atomized SelecCion -Initial Alloy Distribution Prealloyed -Particle Size Distribution -100 Mesh kForging Quality) Uxmtpaction -Lubricant Zinc

  6. Results after Cementless Medial Oxford Unicompartmental Knee Replacement - Incidence of Radiolucent Lines

    PubMed Central

    Panzram, Benjamin; Bertlich, Ines; Reiner, Tobias; Walker, Tilman; Hagmann, Sébastien; Weber, Marc-André; Gotterbarm, Tobias

    2017-01-01

    Purpose Tibial radiolucent lines (RL) are commonly seen in cemented unicompartmental knee replacement (UKR). In the postoperative course, they can be misinterpreted as signs of loosening, thus leading to unnecessary revision. Since 2004, a cementless OUKR is available. First studies and registry data have shown equally good clinical results of cementless OUKR compared to the cemented version and a significantly reduced incidence of RL in cementless implants. Methods This single-centre retrospective cohort study includes the first 30 UKR (27 patients) implanted between 2007 and 2009 with a mean follow-up of 5 years. Clinical outcome was evaluated using the OKS, AKS, range of movement (ROM) and level of pain (VAS). Standard radiologic evaluation was performed at three months, one and five years after surgery. The results five years after implantation were compared to a group of 27 cemented Oxford UKR (OUKR) in a matched-pair-analysis. Results Tibial RL were seen in 10 implants three months after operation, which significantly decreased to five after one year and to three after five years (p = 0.02). RL did not have a significant influence on revision (p = 1.0) or clinical outcome after five years. RL were always partial, never progressive and strictly limited to the tibia. There was no significant difference in the incidence of tibial RL five years after implantation between cemented and cementless implants (cemented: 4, cementless: 3, p = 1.0). Conclusions After cementless implantation RL were limited to the tibia, partial and never progressive. During short term follow-up the incidence of RL decreased significantly. RL seem to have no influence on clinical outcome and revision. PMID:28103308

  7. Study of bone remodeling of two models of femoral cementless stems by means of DEXA and finite elements

    PubMed Central

    2010-01-01

    Background A hip replacement with a cemented or cementless femoral stem produces an effect on the bone called adaptive remodelling, attributable to mechanical and biological factors. All of the cementless prostheses designs try to achieve an optimal load transfer in order to avoid stress-shielding, which produces an osteopenia. Long-term densitometric studies taken after implanting ABG-I and ABG-II stems confirm that the changes made to the design and alloy of the ABG-II stem help produce less proximal atrophy of the femur. The simulation with FE allowed us to study the biomechanical behaviour of two stems. The aim of this study was, if possible, to correlate the biological and mechanical findings. Methods Both models with prostheses ABG-I and II have been simulated in five different moments of time which coincide with the DEXA measurements: postoperative, 6 months, 1, 3 and 5 years, in addition to the healthy femur as the initial reference. For the complete comparative analysis of both stems, all of the possible combinations of bone mass (group I and group II of pacients in two controlled studies for ABG-I and II stems, respectively), prosthetic geometry (ABG-I and ABG-II) and stem material (Wrought Titanium or TMZF) were simulated. Results and Discussion In both groups of bone mass an increase of stress in the area of the cancellous bone is produced, which coincides with the end of the HA coating, as a consequence of the bottleneck effect which is produced in the transmission of loads, and corresponds to Gruen zones 2 and 6, where no osteopenia can be seen in contrast to zones 1 and 7. Conclusions In this study it is shown that the ABG-II stem is more effective than the ABG-I given that it generates higher tensional values on the bone, due to which proximal bone atrophy diminishes. This biomechanical behaviour with an improved transmission of loads confirmed by means of FE simulation corresponds to the biological findings obtained with Dual-Energy X

  8. Hot forging of graphite-carbide composites. Final report

    SciTech Connect

    Jenkins, G.M.; Holland, L.R.

    1998-07-15

    This project was aimed at hot shaping of titanium carbide/graphite and vanadium carbide/graphite composite materials by heating them to above 2000 degrees celsius and pressing into an electrographite die. The sample was to be a preformed cylinder of powdered graphite mixed with powdered titanium or vanadium, lightly sintered. The preform would be heated in a hot press and the titanium or vanadium would react with some of the graphite to form titanium or vanadium carbide. The remaining (excess) graphite would form a composite with the carbide, and this could then be deformed plastically at temperatures well below the onset of plasticity in pure graphite. There were to be two major thrusts in the research: In the first, an electron beam furnace at Sandia Laboratory was to be used for rapid heating of the sample, which would then be transferred into the press. The second thrust was to be entirely at Alabama A and M University, and here they intended to use a heated, controlled atmosphere press to forge the graphite/carbide preforms at a steady temperature and measure their viscosity as a function of temperature. This report discusses the progress made on this project.

  9. Sintering titanium powders

    SciTech Connect

    Gerdemann, Stephen J.; Alman, David E.

    2005-09-01

    Recently, there has been renewed interest in low-cost titanium. Near-net-shape powder metallurgy offers the potential of manufacturing titanium articles without costly and difficult forming and machining operations; hence, processing methods such as conventional press-and-sinter, powder forging and powder injection molding are of interest. The sintering behavior of a variety of commercial and experimental titanium powders was studied. Commercial powders were acquired that were produced different routes: (i) sponge fines from the primary titanium processing; (ii) via the hydride-dehydride process; and (iii) gas atomization. The influence of vacuum sintering time (0.5 to 32 hrs) and temperature (1200, 1275 or 1350°C) on the microstructure (porosity present) of cold pressed powders was studied. The results are discussed in terms of the difference in powder characteristics, with the aim of identify the characteristics required for full density via press-and-sinter processing. Near-net-shape tensile bars were consolidated via cold pressed and sintered. After sintering, a sub-set of the tensile bars was hot-isostatic pressed (HIPed). The microstructure and properties of the bars were compared in the sintered and HIPed conditions.

  10. Deformation processes in forging ceramics

    NASA Technical Reports Server (NTRS)

    Cannon, R. M.; Rhodes, W. H.

    1973-01-01

    The deformation processes involved in the forging of refractory ceramic oxides were investigated. A combination of mechanical testing and forging was utilized to investigate both the flow and fracture processes involved. Deformation studies of very fine grain Al203 revealed an apparent transition in behavior, characterized by a shift in the strain rate sensitivity from 0.5 at low stresses to near unity at higher stresses. The behavior is indicative of a shift in control between two dependent mechanisms, one of which is indicated to be cation limited diffusional creep with significant boundary enhancement. The possible contributions of slip, indicated by crystallographic texture, interface control of the diffusional creep and inhomogeneous boundary sliding are also discussed. Additional experiments indicated an independence of deformation behavior on MgO doping and retained hot pressing impurities, at least for ultrafine grained material, and also an independence of test atmosphere.

  11. Fallon FORGE Well Temp data

    SciTech Connect

    Doug Blankenship

    2016-03-01

    x,y,z downhole temperature data for wells in and around the Fallon FORGE site. Data for the following wells are included: 82-36, 82-19, 84.31, 61-36, 88-24, FOH-3D, FDU-1, and FDU-2. Data are formatted in txt format and in columns for importing into Earthvision Software. Column headers and coordinate system information is stored in the file header.

  12. Cementless acetabular fixation in patients 50 years and younger at 10 to 18 years of follow-up.

    PubMed

    Teusink, Matthew J; Callaghan, John J; Warth, Lucian C; Goetz, Devon D; Pedersen, Douglas R; Johnston, Richard C

    2012-08-01

    The purpose of the study was to evaluate the 10- to 18-year follow-up of cementless acetabular fixation in patients 50 years and younger. We retrospectively reviewed a consecutive group of 118 patients (144 hips) in whom primary total hip arthroplasty had been performed by 2 surgeons using a cementless acetabular component. Two (1.4%) cementless acetabular components were revised because of aseptic loosening. Twenty-four hips (16.7%) were revised for any mechanical failure of the acetabular component mostly related to acetabular liner wear and osteolysis. The average linear wear rate was 0.19 mm per year, which was higher than our previous reports with cemented acetabular fixation. The fiber mesh ingrowth surface of the cementless acetabular component in this study was superior to cemented acetabular components in terms of fixation. However, the high rates of wear and osteolysis have led to poor overall acetabular component construct survivorship.

  13. Cementless total hip arthroplasty in patients with ankylosing spondylitis

    PubMed Central

    Xu, Jun; Zeng, Min; Xie, Jie; Wen, Ting; Hu, Yihe

    2017-01-01

    Abstract Controversies on the surgical protocols and efficacies of total hip arthroplasty (THA) in ankylosing spondylitis (AS) still exist. The aim of this study was to retrospectively analyze the perioperative managements and their outcomes related to performing THA on patients with AS. Data of 54 AS patients who underwent 81 THAs between 2008 and 2014 were retrospectively analyzed. Clinical and imaging data were collected preoperatively, postoperatively, and during the follow-up period for surgical efficacy. Using posterolateral approach, cementless prostheses were selected in all cases. Mean follow-up period was 3.6 years (range, 2–8 years). Inclinations and anteversions of acetabular cups were 36.3°±4.5° (range, 30°–50°) and 12.3°±4.9° (range, 0°–25°) respectively. Mean visual analog scale (VAS) score decreased from 6.7 ± 2.1 (range, 4–10) preoperatively to 1.5 ± 1.0 (range, 0–4) at final follow-up, and mean Harris hip score (HHS) improved from 31.2 ± 11.6 (range, 15–45) to 86.1 ± 4.3 (range, 80–95) (P < 0.05). Postoperative range of motion (ROM) in flexion was improved from 6.7°±13.5° (range, 0°–50°) preoperatively to 82.5°±6.4° (range, 70°–100°) at final follow-up, and ROM in extension was improved from 1.8°±5.7°(range, 0°–15°) to 15.4°±2.6° (range, 10°–20°) (P < 0.05). Heterotopic ossification (HO) was documented in 9 hips (11.1%). Signs of stable fibrous ingrowth and bone ingrowth were detected in 52 and 29 hips, respectively. Sciatic never injury was occurred in 3 cases, and treated conservatively. There were no signs of periprosthetic fractures, dislocation, or prosthesis loosening. Surgical efficacies of THA for AS patients with severe hip involvement are satisfactory. PMID:28121928

  14. Reactor pressure vessel with forged nozzles

    DOEpatents

    Desai, Dilip R.

    1993-01-01

    Inlet nozzles for a gravity-driven cooling system (GDCS) are forged with a cylindrical reactor pressure vessel (RPV) section to which a support skirt for the RPV is attached. The forging provides enhanced RPV integrity around the nozzle and substantial reduction of in-service inspection costs by eliminating GDCS nozzle-to-RPV welds.

  15. Automated Welding of Rotary Forge Hammers

    DTIC Science & Technology

    1994-05-01

    NUMBER OF PAGES Plasma Transferred Arc (PTA) Welding. Metal Inert Gas (MIG) Welding, 34 Metal Powder, Rotary Forge Hammers. Hardfacing 16. PRICE CODE 17...filled with required hardfacing materials ............................................... 26 8. Top and side schematic views, respectively, of forging...superalloy hardfacing deposit. In addition to the hardfacing layer, an underlying layer of buffer material must first be deposited to minimize cracking

  16. Effects of Process Parameters on Deformation and Temperature Uniformity of Forged Ti-6Al-4V Turbine Blade

    NASA Astrophysics Data System (ADS)

    Luo, Shiyuan; Zhu, Dahu; Hua, Lin; Qian, Dongsheng; Yan, Sijie; Yu, Fengping

    2016-11-01

    This work is motivated by the frequent occurrence of macro- and microdefects within forged Ti-6Al-4V turbine blades due to the severely nonuniform strain and temperature distributions. To overcome the problem of nonuniformity during the blade forging operation, firstly, a 2D coupled thermo-mechanical finite element approach using the strain-compensated Arrhenius-type constitutive model is employed to simulate the real movements and processing conditions, and its reliability is verified experimentally. Secondly, two evaluation indexes, standard deviation of equivalent plastic strain and standard deviation of temperature, are proposed to evaluate the uniformity characteristics within the forged blade, and the effects of four process parameters including the forging velocity, friction factor, initial workpiece temperature and dwell time on the uniformity of strain and temperature distributions are carefully studied. Finally, the numerically optimized combination of process parameters is validated by the application in a practical process. The parametric study reveals that a reasonable combination of process parameters considering the flow resistance, flow localization and the effects of deformation and friction heating is crucial for the titanium alloy blade forging with uniformity. This work can provide a significant guidance for the design and optimization of blade forging processes.

  17. Forging of Advanced Disk Alloy LSHR

    NASA Technical Reports Server (NTRS)

    Gabb, Timothy P.; Gayda, John; Falsey, John

    2005-01-01

    The powder metallurgy disk alloy LSHR was designed with a relatively low gamma precipitate solvus temperature and high refractory element content to allow versatile heat treatment processing combined with high tensile, creep and fatigue properties. Grain size can be chiefly controlled through proper selection of solution heat treatment temperatures relative to the gamma precipitate solvus temperature. However, forging process conditions can also significantly influence solution heat treatment-grain size response. Therefore, it is necessary to understand the relationships between forging process conditions and the eventual grain size of solution heat treated material. A series of forging experiments were performed with subsequent subsolvus and supersolvus heat treatments, in search of suitable forging conditions for producing uniform fine grain and coarse grain microstructures. Subsolvus, supersolvus, and combined subsolvus plus supersolvus heat treatments were then applied. Forging and subsequent heat treatment conditions were identified allowing uniform fine and coarse grain microstructures.

  18. Comparison of Clinical Efficacy Between Modular Cementless Stem Prostheses and Coated Cementless Long-Stem Prostheses on Bone Defect in Hip Revision Arthroplasty

    PubMed Central

    Li, Huibin; Chen, Fang; Wang, Zhe; Chen, Qian

    2016-01-01

    Background The aim of this study was to investigate and compare the clinical efficacy of modular cementless stem and coated cementless long-stem prostheses in hip revision arthroplasty. Material/Methods Sixty-five patients with complete hip revision surgery data during January 2005 to March 2015 were selected from the People’s Hospital of Linyi City and randomly divided into a S-ROM group (implanted with cementless modular stem prostheses, n=32) and a SLR-PLUS group (implanted with cementless coated long-stem prostheses, n=33). Harris score was used to evaluate the hip function of the patients in order to measure the clinical efficacy of the prostheses in total hip arthroplasty. Anteroposterior pelvic radiographs and lateral pelvic radiographs were taken and each patient’s hip arthroplasty condition was recorded. Kaplan-Meier method was applied to compare the cumulative 5-year non-revision rate between the 2 prostheses and log-rank method was used to inspect the statistical data. Results The Harris scores of both the S-ROM group and the SLR-PLUS group were significantly higher at 12 months after the operation than those before the operation (both P<0.05). The Harris scores of the patients with type I/II bone defects in the S-ROM group were not significantly different from those of the same types in the SLR-PLUS group at all time points (all P>0.05), while the Harris scores of the patients with type IIIA/IIIB in the S-ROM group were both significantly higher than those of the same types in the SLR-PLUS group at 3 months, 6 months, and 12 months after the operation (all P<0.05). No significant difference was found in the cumulative 5-year non-revision rate between the type I/II patients in the S-ROM group (92.31%) and the patients of the same types in the SLR-PLUS group (85.71%) (P>0.05). However, the cumulative 5-year non-revision rate of the type IIIA/IIIB patients in the S-ROM group (89.47%) was significantly different from the patients of the same types in

  19. Bone scans after total knee arthroplasty in asymptomatic patients. Cemented versus cementless

    SciTech Connect

    Hofmann, A.A.; Wyatt, R.W.; Daniels, A.U.; Armstrong, L.; Alazraki, N.; Taylor, A. Jr. )

    1990-02-01

    The natural history of bone scans after total knee arthroplasty (TKA) was studied in 26 patients with 28 cemented TKAs and 29 patients with 31 cementless TKAs. The bone scans were examined at specified postoperative intervals. Radionuclide activity of the femoral, tibial, and patellar regions was measured. Six patients who developed pain postoperatively were excluded. Bone scans immediately postoperative and at three months demonstrated increased uptake, which gradually decreased to baseline levels at ten to 12 months. Radioisotope uptake was comparable in the cemented and cementless groups, but was highly variable in individual patients and in each of the follow-up periods. A single postoperative bone scan cannot differentiate component loosening from early bone remodeling. Sequential bone scans, as a supplement to the clinical examination and conventional radiography, may prove useful in the diagnosis of TKA failure.

  20. Cavitary acetabular defects treated with morselized cancellous bone graft and cementless cups

    PubMed Central

    Pereira, G. C.T.; Kubiak, E. N.; Levine, B.; Chen, F. S.

    2006-01-01

    The use of impacted morselized cancellous bone grafts in conjunction with cementless hemispherical acetabular cups for treatment of AAOS type II acetabular cavitary deficiencies was evaluated in a retrospective study of 23 primary and 24 revision total hip arthroplasties, at a mean follow-up of 7.9 and 8.1 years, respectively. All primary hips received autografts, while all revision hips received allografts. Modified Harris Hip Scores for primary and revision hip replacements increased from a pre-operative mean of 37 and 47 to a postoperative mean of 90 and 86, respectively. All 23 autografts and 23 out of 24 cancellous allografts were radiographically incorporated without evidence of resorption. There were no instances of infection, component migration, or cases requiring subsequent acetabular revision. We conclude that impacted morselized cancellous bone-graft augmentation of cementless cups is a viable surgical option for AAOS type II cavitary acetabular defects. PMID:16988799

  1. Total hip replacement: A meta-analysis to evaluate survival of cemented, cementless and hybrid implants

    PubMed Central

    Phedy, Phedy; Ismail, H Dilogo; Hoo, Charles; Djaja, Yoshi P

    2017-01-01

    AIM To determine whether cemented, cementless, or hybrid implant was superior to the other in terms of survival rate. METHODS Systematic searches across MEDLINE, CINAHL, and Cochrane that compared cemented, cementless and hybrid total hip replacement (THR) were performed. Two independent reviewers evaluated the risk ratios of revision due to any cause, aseptic loosening, infection, and dislocation rate of each implants with a pre-determined form. The risk ratios were pooled separately for clinical trials, cohorts and registers before pooled altogether using fixed-effect model. Meta-regressions were performed to identify the source of heterogeneity. Funnel plots were analyzed. RESULTS Twenty-seven studies comprising 5 clinical trials, 9 cohorts, and 13 registers fulfilled the research criteria and analyzed. Compared to cementless THR, cemented THR have pooled RR of 0.47 (95%CI: 0.45-0.48), 0.9 (0.84-0.95), 1.29 (1.06-1.57) and 0.69 (0.6-0.79) for revision due to any reason, revision due to aseptic loosening, revision due to infection, and dislocation respectively. Compared to hybrid THR, the pooled RRs of cemented THR were 0.82 (0.76-0.89), 2.65 (1.14-6.17), 0.98 (0.7-1.38), and 0.67 (0.57-0.79) respectively. Compared to hybrid THR, cementless THR had RRs of 0.7 (0.65-0.75), 0.85 (0.49-1.5), 1.47 (0.93-2.34) and 1.13 (0.98-1.3). CONCLUSION Despite the limitations in this study, there was some tendency that cemented fixation was still superior than other types of fixation in terms of implant survival. PMID:28251071

  2. Design of forging process variables under uncertainties

    NASA Astrophysics Data System (ADS)

    Repalle, Jalaja; Grandhi, Ramana V.

    2005-02-01

    Forging is a complex nonlinear process that is vulnerable to various manufacturing anomalies, such as variations in billet geometry, billet/die temperatures, material properties, and workpiece and forging equipment positional errors. A combination of these uncertainties could induce heavy manufacturing losses through premature die failure, final part geometric distortion, and reduced productivity. Identifying, quantifying, and controlling the uncertainties will reduce variability risk in a manufacturing environment, which will minimize the overall production cost. In this article, various uncertainties that affect the forging process are identified, and their cumulative effect on the forging tool life is evaluated. Because the forging process simulation is time-consuming, a response surface model is used to reduce computation time by establishing a relationship between the process performance and the critical process variables. A robust design methodology is developed by incorporating reliability-based optimization techniques to obtain sound forging components. A case study of an automotive-component forging-process design is presented to demonstrate the applicability of the method.

  3. Near Net Shape Manufacturing of New Titanium Powders for Industry

    SciTech Connect

    2009-05-01

    This factsheet describes a research project whose goal is to develop a manufacturing technology to process new titanium powders into fully consolidated near net shape components for industrial applications. This will be achieved using various technologies, including press and sinter, pneumatic isostatic forging (PIF), hot isostatic pressing (HIP), and adiabatic compaction.

  4. Comparative Study of Bipolar Hemiarthroplasty for Femur Neck Fractures Treated with Cemented versus Cementless Stem

    PubMed Central

    Choi, Jung-Yun; Kim, Joo-Hyung

    2016-01-01

    Purpose To compare and analyze clinical and radiologic outcomes of cemented versus cementless bipolar hemiarthroplasty for treatment of femur neck fractures. Materials and Methods A total of 180 patients aged 65 years and over older who underwent bipolar hemiarthroplasty for treatment of displaced femur neck fractures (Garden stage III, IV) from March 2009 to February 2014 were included in this study. Among the 180 patients, 115 were treated with cemented stems and 65 patients with cementless stems. Clinical outcomes assessed were: i) postoperative ambulatory status, ii) inguinal and thigh pain, and iii) complications. The radiologic outcome was femoral stem subsidence measured using postoperative simple X-ray. Results The cemented group had significantly lower occurrence of complications (postoperative infection, P=0.04) compared to the cementless group. There was no significant difference in postoperative ambulatory status, inguinal and thigh pain, and femoral stem subsidence. Conclusion For patients undergoing bipolar hemiarthroplasty, other than complications, there was no statistically significant difference in clinical or radiologic outcomes in our study. Selective use of cemented stem in bipolar hemiarthroplasty may be a desirable treatment method for patients with poor bone quality and higher risk of infections. PMID:28097110

  5. Processing and Characterization of Sub-delta Solvus Forged Hemispherical Forgings of Inconel 718

    NASA Astrophysics Data System (ADS)

    Chenna Krishna, S.; Rao, G. Sudarasana; Singh, Satish Kumar; Narayana Murty, S. V. S.; Venkatanarayana, G.; Jha, Abhay K.; Pant, Bhanu; Venkitakrishnan, P. V.

    2016-12-01

    In this paper, microstructure and mechanical properties of 200 mm diameter Inconel 718 hemispherical domes processed at 1025 °C through closed die hammer forging have been investigated. Microstructure and mechanical properties of the forgings in radial and tangential directions were characterized using optical microscopy, scanning electron microscopy, impact testing, and tensile testing. Grain size of the forgings at three different locations was fine with an average grain size of ASTM No. 8-9. The typical tensile properties of the forgings in solution-treated and aged condition were ultimate tensile strength-1450 MPa, yield strength-1240 MPa, and ductility-25%. The fine grain size achieved in forgings has been attributed to delta phase present at grain boundaries which pinned the grains during forging and prevented grain coarsening.

  6. Forging and Stamping Nonferrous Metals. Handbook.

    DTIC Science & Technology

    1984-05-10

    Tools, Power of Machines ............................................................ 199 Chapter IV. Elements of Construction of Stampings and Tools... Power of Machines ............................................................... 230 Chapter V. Technology of Forging and Stamping...Alloys ........ 570 References ............................................................... 603 Table of Contents

  7. Forging of FeAl intermetallic compounds

    SciTech Connect

    Flores, O.; Juarez, J.; Campillo, B.; Martinez, L.; Schneibel, J.H.

    1994-09-01

    Much activity has been concentrated on the development of intermetallic compounds with the aim of improving tensile ductility, fracture toughness and high notch sensitivity in order to develop an attractive combination of properties for high and low temperature applications. This paper reports experience in processing and forging of FeAl intermetallic of B2 type. During the experiments two different temperatures were employed, and the specimens were forged after annealing in air, 10{sup {minus}2} torr vacuum and argon. From the results it was learned that annealing FeAl in argon atmosphere prior to forging resulted in better deformation behavior than for the other two environments. For the higher forging temperature used in the experiments (700C), the as-cast microstructure becomes partially recrystallized.

  8. Comparison of Biocompatibility of Cemented vs. Cementless Hip Joint Endoprostheses Based on Postoperative Evaluation of Proinflammatory Cytokine Levels

    PubMed Central

    Szypuła, Jan; Cabak, Anna; Kiljański, Marek; Boguszewski, Dariusz; Tomaszewski, Wiesław

    2016-01-01

    Background The yearly increase in the number of procedures involving implantation of hip joint endoprostheses forces prosthetics manufacturers to search for biologically neutral implants. The goal of this study was to assess the concentration of Interleukin-6 (IL-6) and its correlation with C-reactive protein (CRP), depending on the type of hip joint endoprosthesis (cemented or cementless endoprosthesis) in order to determine implant biotolerance during the early postoperative period. Material/Methods The sample comprised 200 patients [mean age=64 (31–81) years] with coxarthrosis. All patients underwent hip joint arthroplasty using a cemented or cementless endoprosthesis. Blood samples were collected 3 times: before the procedure, on the first day after the procedure, and after 6 weeks. IL-6 and CRP levels were assayed using immunoenzymatic methods. The results were subjected to statistical analysis using the Shapiro-Wilk test. Results On the 1st day after the procedure, CRP and IL-6 concentration increased rapidly after implantation of both cemented and cementless endoprostheses. At 6 weeks postoperatively, the CRP value remained at a similar level in patients after cemented arthroplasty and was almost 2-fold lower in patients who underwent cementless arthroplasty. The IL-6 value returned to the baseline level in patients after cementless arthroplasty and showed an ongoing increasing tendency in patients after cemented arthroplasty. Conclusions 1. The measurement of C-reactive protein and Interleukin-6 is a high-sensitivity test, assessing implant biotolerance. 2. The implantation of a cemented endoprosthesis induces a higher increase in the level of proinflammatory cytokines as compared with a cementless endoprosthesis. 3. For a complete assessment of both early and later body responses to implantation and the related surgical procedure, further studies using available approaches and tools are recommended. PMID:27935873

  9. Compressed Air System Optimization Project Improves Production at a Metal Forging Plant (Modern Forge, TN, Plant)

    SciTech Connect

    2000-12-01

    In 1995, Modern Forge of Tennessee implemented a compressed air system improvement project at its Piney Flats, Tennessee, forging plant. Due to the project’s implementation, the plant was able to operate with fewer compressors and improve its product quality, thus allowing it to increase productivity. The project also resulted in considerable energy and maintenance savings.

  10. Cementless Total Hip Arthroplasty Involving Trochanteric Osteotomy without Subtrochanteric Shortening for High Hip Dislocation

    PubMed Central

    Lee, Soong Joon; Kim, Hee Joong

    2017-01-01

    Background Total hip arthroplasty with subtrochanteric shortening osteotomy is widely performed for high hip dislocation. However, suboptimal leg length discrepancy correction and nonunion of the osteotomy site remain concerns. Although total hip arthroplasty using trochanteric osteotomy without subtrochanteric osteotomy was introduced, cemented implants have been more commonly used than contemporary cementless implants in this procedure. We evaluated the long-term results of cementless total hip arthroplasty with trochanteric osteotomy without subtrochanteric osteotomy for high hip dislocation. Methods From 1990 to 2002, 27 cementless total hip arthroplasties using trochanteric osteotomy without subtrochanteric osteotomy were performed in 26 patients with Crowe III or IV high hip dislocation and a mean age of 36.4 ± 12.9 years. Seven ceramic-on-ceramic, 8 ceramic-on-polyethylene, 10 metal-on-polyethylene, and 2 metal-on-metal bearings were inserted. Mean follow-up was 15.1 ± 3.7 years. We retrospectively reviewed medical records and radiographic data and evaluated the clinical and radiological results including the Harris hip score, implant survival, correction of leg length discrepancy, and occurrence of complications. Results The mean Harris hip score and leg length discrepancy improved significantly from 73.3 to 94.9 points and from 4.3 cm to 1.0 cm, respectively. With revision for loosening set as the end point, implant survival rates at 10 and 15 years postoperatively were 96.0% and 90.9% for stems and 74.1% and 52.3% for cups. In 8 of 10 hips with the metal-on-polyethylene bearing and 4 of 8 hips with the ceramic-on-polyethylene bearing, revision surgery was performed for aseptic loosening. However, no revision was performed in hips with the ceramic-on-ceramic bearing or the metal-on-metal bearing. Implant survival was significantly different by the type of bearing surface. Two permanent neurologic complications occurred in patients with a limb lengthening

  11. Stainless-steel elbows formed by spin forging

    NASA Technical Reports Server (NTRS)

    1964-01-01

    Large seamless austenitic stainless steel elbows are fabricated by spin forging /rotary shear forming/. A specially designed spin forging tool for mounting on a hydrospin machine has been built for this purpose.

  12. 1. MIDDLE FORGE DISPLAY, ACROSS FROM BUILDING NO. 114 on ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. MIDDLE FORGE DISPLAY, ACROSS FROM BUILDING NO. 114 on FARLEY AVE. MARKER ON DISPLAY ITSELF READS: FORGE AND TOOLS, USED AT MIDDLE FORGE LOCATED AT PICATINNY LAKE OUTLETS 1749 TO 1880. NEARBY MARKER READS: THE MIDDLE FORGE. THE MT. HOPE IRONWORKS INCLUDING A TRACT CALLED THE MIDDLE FORGE, SUPPLIED ORDNANCE MATERIAL TO THE CONTINENTAL ARMY IN THE AMERICAN REVOLUTION. GENERAL WASHINGTON INSPECTED THE FACILITY. THE WAR DEPARTMENT PURCHASED THE MIDDLE FORGE PORPERTY FOR AN ARMY POWDER DEPOT IN 1879-80. THE FORGE AND TOOLS WERE RECOVERED AT THE ACTUAL SITE NEAR PICATINNY PEAK. THROUGH THE YEARS, THE MIDDLE FORGE DISPLAY CAME TO BE THE UNOFFICIAL SYMBOL OF PICATINNY ARSENAL. -- HISTORICAL OFFICE NO DATE - Picatinny Arsenal, State Route 15 near I-80, Dover, Morris County, NJ

  13. 4. FORGE, ANVIL, PEDESTAL GRINDER, AND BELT DRIVES. NOTE WATERWHEEL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. FORGE, ANVIL, PEDESTAL GRINDER, AND BELT DRIVES. NOTE WATERWHEEL NEEDLE VALVE CASTING HANGING ON THE WALL ABOVE THE FORGE. VIEW TO NORTH. - Santa Ana River Hydroelectric System, SAR-1 Machine Shop, Redlands, San Bernardino County, CA

  14. Titanium 2013

    USGS Publications Warehouse

    2014-01-01

    Titanium is the ninth most abundant element in the earth's crust and can be found in nearly all rocks and sediments. It is a lithophile element with a strong affinity for oxygen and is not found as a pure metal in nature. Titanium was first isolated as a pure metal in 1910, but it was not until 1948 that the metal was produced commercially using the Kroll process (named after its developer, William Kroll) to reduce titanium tetrachloride with magnesium to produce titanium metal.

  15. Near-Net Forging Technology Demonstration Program

    NASA Technical Reports Server (NTRS)

    Hall, I. Keith

    1996-01-01

    Significant advantages in specific mechanical properties, when compared to conventional aluminum (Al) alloys, make aluminum-lithium (Al-Li) alloys attractive candidate materials for use in cryogenic propellant tanks and dry bay structures. However, the cost of Al-Li alloys is typically five times that of 2219 aluminum. If conventional fabrication processes are employed to fabricate launch vehicle structure, the material costs will restrict their utilization. In order to fully exploit the potential cost and performance benefits of Al-Li alloys, it is necessary that near-net manufacturing methods be developed to off-set or reduce raw material costs. Near-net forging is an advanced manufacturing method that uses elevated temperature metal movement (forging) to fabricate a single piece, near-net shape, structure. This process is termed 'near-net' because only a minimal amount of post-forge machining is required. The near-net forging process was developed to reduce the material scrap rate (buy-to-fly ratio) and fabrication costs associated with conventional manufacturing methods. The goal for the near-net forging process, when mature, is to achieve an overall cost reduction of approximately 50 percent compared with conventional manufacturing options for producing structures fabricated from Al-Li alloys. This NASA Marshall Space Flight Center (MSFC) sponsored program has been a part of a unique government / industry partnership, coordinated to develop and demonstrate near-net forging technology. The objective of this program was to demonstrate scale-up of the near-net forging process. This objective was successfully achieved by fabricating four integrally stiffened, 170- inch diameter by 20-inch tall, Al-Li alloy 2195, Y-ring adapters. Initially, two 2195 Al-Li ingots were converted and back extruded to produce four cylindrical blockers. Conventional ring rolling of the blockers was performed to produce ring preforms, which were then contour ring rolled to produce

  16. 76 FR 168 - Heavy Forged Hand Tools From China

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-03

    ... COMMISSION Heavy Forged Hand Tools From China AGENCY: United States International Trade Commission. ACTION: Institution of five-year reviews concerning the antidumping duty orders on heavy forged hand tools from China... antidumping duty orders on heavy forged hand tools from China would be likely to lead to continuation...

  17. Co-Operative Training in the Sheffield Forging Industry

    ERIC Educational Resources Information Center

    Duncan, R.

    2008-01-01

    Purpose: The purpose of this paper is to give details of an operation carried out in Sheffield to increase the recruitment of young men into the steel forging industry. Design/methodology/approach: The Sheffield Forges Co-operative Training Scheme was designed to encourage boys to enter the forging industry and to provide them with training and…

  18. 76 FR 50755 - Heavy Forged Hand Tools From China

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-16

    ... COMMISSION Heavy Forged Hand Tools From China Determinations On the basis of the record \\1\\ developed in the... antidumping duty orders on heavy forged hand tools from China would be likely to lead to continuation or... Forged Hand Tools From China: Investigation Nos. 731-TA-457-A-D (Third Review). Issued: August 10,...

  19. Intra-operative evaluation of cementless hip implant stability: a prototype device based on vibration analysis.

    PubMed

    Lannocca, Maurizio; Varini, Elena; Cappello, Angelo; Cristofolini, Luca; Bialoblocka, Ewa

    2007-10-01

    Cementless implants are mechanically stabilized during surgery by a press-fitting procedure. Good initial stability is crucial to avoid stem loosening and bone cracking, therefore, the surgeon must achieve optimal press-fitting. A possible approach to solve this problem and assist the surgeon in achieving the optimal compromise, involves the use of vibration analysis. The present study aimed to design and test a prototype device able to evaluate the primary mechanical stability of a cementless prosthesis, based on vibration analysis. In particular, the goal was to discriminate between stable and quasi-stable implants; thus the stem-bone system was assumed to be linear in both cases. For that reason, it was decided to study the frequency responses of the system, instead of the harmonic distortion. The prototype developed consists of a piezoelectric exciter connected to the stem and an accelerometer attached to the femur. Preliminary tests were performed on four composite femurs implanted with a conventional stem. The results showed that the input signal was repeatable and the output could be recorded accurately. The most sensitive parameter to stability was the shift in resonance frequency of the stem-bone system, which was highly correlated with residual micromotion on all four specimens.

  20. A genetic algorithm based multi-objective shape optimization scheme for cementless femoral implant.

    PubMed

    Chanda, Souptick; Gupta, Sanjay; Kumar Pratihar, Dilip

    2015-03-01

    The shape and geometry of femoral implant influence implant-induced periprosthetic bone resorption and implant-bone interface stresses, which are potential causes of aseptic loosening in cementless total hip arthroplasty (THA). Development of a shape optimization scheme is necessary to achieve a trade-off between these two conflicting objectives. The objective of this study was to develop a novel multi-objective custom-based shape optimization scheme for cementless femoral implant by integrating finite element (FE) analysis and a multi-objective genetic algorithm (GA). The FE model of a proximal femur was based on a subject-specific CT-scan dataset. Eighteen parameters describing the nature of four key sections of the implant were identified as design variables. Two objective functions, one based on implant-bone interface failure criterion, and the other based on resorbed proximal bone mass fraction (BMF), were formulated. The results predicted by the two objective functions were found to be contradictory; a reduction in the proximal bone resorption was accompanied by a greater chance of interface failure. The resorbed proximal BMF was found to be between 23% and 27% for the trade-off geometries as compared to ∼39% for a generic implant. Moreover, the overall chances of interface failure have been minimized for the optimal designs, compared to the generic implant. The adaptive bone remodeling was also found to be minimal for the optimally designed implants and, further with remodeling, the chances of interface debonding increased only marginally.

  1. Process for synthesizing titanium carbide, titanium nitride and titanium carbonitride

    DOEpatents

    Koc, Rasit; Glatzmaier, Gregory C.

    1995-01-01

    A process for synthesizing titanium carbide, titanium nitride or titanium carbonitride. The process comprises placing particles of titanium, a titanium salt or titanium dioxide within a vessel and providing a carbon-containing atmosphere within the vessel. The vessel is heated to a pyrolysis temperature sufficient to pyrolyze the carbon to thereby coat the particles with a carbon coating. Thereafter, the carbon-coated particles are heated in an inert atmosphere to produce titanium carbide, or in a nitrogen atmosphere to produce titanium nitride or titanium carbonitride, with the heating being of a temperature and time sufficient to produce a substantially complete solid solution.

  2. Process for synthesizing titanium carbide, titanium nitride and titanium carbonitride

    DOEpatents

    Koc, R.; Glatzmaier, G.C.

    1995-05-23

    A process is disclosed for synthesizing titanium carbide, titanium nitride or titanium carbonitride. The process comprises placing particles of titanium, a titanium salt or titanium dioxide within a vessel and providing a carbon-containing atmosphere within the vessel. The vessel is heated to a pyrolysis temperature sufficient to pyrolyze the carbon to thereby coat the particles with a carbon coating. Thereafter, the carbon-coated particles are heated in an inert atmosphere to produce titanium carbide, or in a nitrogen atmosphere to produce titanium nitride or titanium carbonitride, with the heating being of a temperature and time sufficient to produce a substantially complete solid solution.

  3. Forging Collaborative Partnerships: The Waterloo Neighborhood Project.

    ERIC Educational Resources Information Center

    Gruenewald, Anne

    The Forging Collaborative Partnerships Project in Waterloo, Iowa is a collaborative venture to assist voluntary agencies in developing tools and strategies to strengthen collaborative relationships among public and nonprofit child welfare agencies and other key stakeholders as they adopt a family-focused philosophy. This monograph details how the…

  4. Forging Inclusive Solutions: Experiential Earth Charter Education

    ERIC Educational Resources Information Center

    Hill, Linda D.

    2010-01-01

    Forging Inclusive Solutions describes the aims, methodology and outcomes of Inclusive Leadership Adventures, an experiential education curriculum for exploring the Earth Charter. Experiential education builds meaningful relationships, skills, awareness and an inclusive community based on the Earth Charter principles. When we meet people where they…

  5. Wrought processing of ingot-metallurgy gamma titanium aluminide alloys

    SciTech Connect

    Semiatin, S.L.

    1995-12-31

    The wrought processing of ingot-metallurgy, gamma titanium aluminide alloys is reviewed. Attention is focused on five major areas in the development of thermomechanical processes for these materials: (1) ingot structure and homogenization, (2) ingot breakdown via existing techniques, (3) novel processes for ingot breakdown, (4) secondary processing, and (5) process scaleup considerations. The nature of the cast microstructure and the influence of composition and ingot size on grain size and segregation are described. The design of existing processes for ingot breakdown deals with the selection of process variables and the design of cans for nonisothermal metalworking techniques. Novel breakdown processes, including smart forging, alpha forging, controlled dwell extrusion, and equal channel angular extrusion, are reviewed. In the area of secondary processing, developments related to pack rolling of sheet, superplastic sheet forming, and isothermal, closed-die forging are summarized. Lastly, scaleup considerations such as thermal cracking during ingot production are addressed.

  6. Performance of Porous Tantalum vs. Titanium Cup in Total Hip Arthroplasty: Randomized Trial with Minimum 10-Year Follow-Up.

    PubMed

    Wegrzyn, Julien; Kaufman, Kenton R; Hanssen, Arlen D; Lewallen, David G

    2015-06-01

    Porous tantalum monoblock cups have been proposed to improve survivorship of cementless primary THA. However, there are few direct comparative trials to established implants such as porous-coated titanium cups. 113 patients were randomized into two groups according to the cup: a porous tantalum monoblock cup (TM) or a porous-coated titanium monoblock cup (control). At a mean of 12 years after THA, no implants migrated in both groups. Two TM patients (4%) and 13 control patients (33%) presented with radiolucency around the cup (P<0.001). In the control group, 1 cup (2%) was revised for aseptic loosening. At 12 years post-implantation, porous tantalum monoblock cups demonstrated 100% survivorship, and significantly less radiolucency as compared to porous-coated titanium monoblock cups.

  7. 2014 Accomplishments-Tritium aging studies on stainless steel: Fracture toughness properties of forged stainless steels-Effect of hydrogen, forging strain rate, and forging temperature

    SciTech Connect

    Morgan, Michael J.

    2015-02-01

    Forged stainless steels are used as the materials of construction for tritium reservoirs. During service, tritium diffuses into the reservoir walls and radioactively decays to helium-3. Tritium and decay helium cause a higher propensity for cracking which could lead to a tritium leak or delayed failure of a tritium reservoir. The factors that affect the tendency for crack formation and propagation include: Environment; steel type and microstructure; and, vessel configuration (geometry, pressure, residual stress). Fracture toughness properties are needed for evaluating the long-term effects of tritium on their structural properties. Until now, these effects have been characterized by measuring the effects of tritium on the tensile and fracture toughness properties of specimens fabricated from experimental forgings in the form of forward-extruded cylinders. A key result of those studies is that the long-term cracking resistance of stainless steels in tritium service depends greatly on the interaction between decay helium and the steels’ forged microstructure. New experimental research programs are underway and are designed to measure tritium and decay helium effects on the cracking properties of stainless steels using actual tritium reservoir forgings instead of the experimental forgings of past programs. The properties measured should be more representative of actual reservoir properties because the microstructure of the specimens tested will be more like that of the tritium reservoirs. The programs are designed to measure the effects of key forging variables on tritium compatibility and include three stainless steels, multiple yield strengths, and four different forging processes. The effects on fracture toughness of hydrogen and crack orientation were measured for type 316L forgings. In addition, hydrogen effects on toughness were measured for Type 304L block forgings having two different yield strengths. Finally, fracture toughness properties of type 304L

  8. Radiographic wear measurements in a cementless metal-backed modular cobalt-chromium acetabular component.

    PubMed

    Barrack, R L; Lavernia, C; Szuszczewicz, E S; Sawhney, J

    2001-10-01

    Linear polyethylene wear was measured radiographically and correlated with direct measurements of wear from 21 of 24 liners retrieved at revision. An optical comparator was used to assess linear wear using the shadowgraph technique. Postoperative and prerevision radiographs were reviewed to measure the amount of linear wear radiographically. Seven radiographic methods described in the literature were used: 5 were manual techniques, and 2 techniques used a computer-assisted digitizer. Linear regression analysis showed that there was a statistically significant correlation between the radiographic measurements compared with the direct measurement for 4 of the 5 manual techniques but only 1 of the 2 computerized techniques. Based on these results, radiographic wear measurements of cementless, modular components should be considered qualitative rather than quantitative. There is a significant difference in the measurements obtained among various published techniques. The addition of computer digitization to enhance manual methodology does not improve accuracy.

  9. Total hip arthroplasty using a cylindrical cementless stem in patients with a small physique.

    PubMed

    Nakamura, Yoshihide; Mitsui, Hiromasa; Kikuchi, Akira; Toh, Satoshi; Katano, Hiroshi

    2011-01-01

    We performed total hip arthroplasty using an anatomic medullary locking cementless stem for small-physique patients from 1988 to 1995. We conducted a retrospective study of 50 joints in 44 cases, including 40 developmentally dysplastic hips followed for 12 to 20 years (average, 15.1 years). Average height and body weight were 152 cm and 56 kg (5.0 ft and 124 lb), respectively, with an average body mass index of 24.2. Twelve joints (24%) were revised for acetabular-sided failures. Forty-eight stems (96%) showed bone ingrowth fixation, and there were no unstable stems. The simple cylindrical shape of the distal portion of the AML stem was less affected by deformity of the proximal femur of developmental dysplasia of the hip in patients with a small physique, and both clinically and radiologically good results were confirmed at long-term follow-up.

  10. Acoustic pattern evaluation during cementless hip arthroplasty surgery may be a new method for predicting complications

    PubMed Central

    Morohashi, Itaru; Iwase, Hideaki; Kanda, Akio; Sato, Taichi; Homma, Yasuhiro; Mogami, Atsuhiko; Obayashi, Osamu; Kaneko, Kazuo

    2017-01-01

    Background: Although surgeons must perform implantation of the cementless stem during total hip arthroplasty (THA) without complications, assessment is left to the surgeon’s intuitive judgement, which could contain inter/intra-observer bias variety. We therefore asked (1) whether the sound created during the stem implantation could be evaluated objectively and (2) whether those sounds are correlate to the complication specific to the cementless stems. Our hypothesis is that the sounds produced during stem insertion could be quantified and related to the complications. Patients and method: In 71 THAs, we quantified the sound produced during stem insertion and investigated the relationship between these sounds and the occurrence of intraoperative fracture and subsidence. Results: The sound data were divided into two patterns: Patterns A and B. The difference between the peak value (dB) at the most common frequency (near 7 kHz) and the second most common frequency (near 4 kHz) of strikes during the final phase of implantation in Patterns A and B showed a significant difference. Adverse events on intraoperative fracture and subsidence were significantly less common in patients with Pattern A than in those with Pattern B (six of 42 hips with Pattern A and 13 of 29 hips with Pattern B, p = 0.004). Pattern A in predicting a clinical course without those adverse events was 69.2% and the specificity was 68.4%. Positive and negative predictive values were 85.7% and 44.8%, respectively. Conclusion: The sound generated during stem insertion was quantified. Those sound patterns were associated with complications. PMID:28186872

  11. A biodegradable gentamicin-hydroxyapatite-coating for infection prophylaxis in cementless hip prostheses.

    PubMed

    Neut, D; Dijkstra, R J; Thompson, J I; Kavanagh, C; van der Mei, H C; Busscher, H J

    2015-01-02

    A degradable, poly (lactic-co-glycolic acid) (PLGA), gentamicin-loaded prophylactic coating for hydroxyapatite (HA)-coated cementless hip prostheses is developed with similar antibacterial efficacy as offered by gentamicin-loaded cements for fixing traditional, cemented prostheses in bone. We describe the development pathway, from in vitro investigation of antibiotic release and antibacterial properties of this PLGA-gentamicin-HA-coating in different in vitro models to an evaluation of its efficacy in preventing implant-related infection in rabbits. Bone in-growth in the absence and presence of the coating was investigated in a canine model. The PLGA-gentamicin-HA-coating showed high-burst release, with antibacterial efficacy in agar-assays completely disappearing after 4 days, minimising risk of inducing antibiotic resistance. Gentamicin-sensitive and gentamicin-resistant staphylococci were killed by the antibiotic-loaded coating, in a simulated prosthesis-related interfacial gap. PLGA-gentamicin-HA-coatings prevented growth of bioluminescent staphylococci around a miniature-stem mounted in bacterially contaminated agar, as observed using bio-optical imaging. PLGA-gentamicin-HA-coated pins inserted in bacterially contaminated medullary canals in rabbits caused a statistically significant reduction in infection rates compared to HA-coated pins without gentamicin. Bone ingrowth to PLGA-gentamicin-HA-coated pins, in condylar defects of Beagle dogs was not impaired by the presence of the degradable, gentamicin-loaded coating. In conclusion, the PLGA-gentamicin-HA-coating constitutes an effective strategy for infection prophylaxis in cementless prostheses.

  12. Experimental study of multiple scattering in anisotropic titanium alloys

    NASA Astrophysics Data System (ADS)

    Baelde, Aurelien; Laurent, Jérôme; Coulette, Richard; Khalifa, Warida Ben; Duclos, Daniel; Jenson, Frédéric; Fink, Mathias; Prada, Claire

    2017-02-01

    Ultrasonic testing of jet engine titanium alloys is of high importance for the aircraft manufacturing industry. The quality of ultrasonic non-destructive testing is severely impacted by the titanium complex microstructure. These alloys have been extensively studied and single scattering models are now well known and implemented in ultrasonic propagation simulators. In addition, titanium billets and forged parts have been known to exhibit a highly anisotropic microstructure. We studied ultrasonic wave scattering in Ti17 forged disk, through statistical analysis of the backscattered noise generated by the microstructure. More specifically, we focused on the quantification of multiple scattering relative to single scattering in the backscattered wave. To that end, we used the full matrix capture acquisition with a linear transducer array. Two phenomena were used to quantify the proportion of single scattering with respect to multiple scattering. The first is the coherent backscattering effect, used as a binary indicator of multiple scattering. The second is a repurposed version of the multiple scattering filter, recently developed on random rod forest and applied on Inconel alloys. With these methods, significant level of multiple scattering was consistently measured in Ti17 forged disks, showing that ultrasonic testing could be enhanced by filtering the multiple scattering contribution.

  13. Improvements in the process of boss bar upset forging into a horizontal forging machine with the aim of joint knuckle forging quality improvement

    NASA Astrophysics Data System (ADS)

    Pankratov, D. L.; Nizamov, R. S.; Kharisov, I. Zh

    2016-06-01

    A new technique for tapered composing transition shaping has been put forward in the process of upset forging with the use of an experimental tool. The results of the upset forging process with the use of a new composing transition has been computer simulated.

  14. Enhancement of Aluminum Alloy Forgings through Rapid Billet Heating

    SciTech Connect

    Kervick, R.; Blue, C. A.; Kadolkar, P. B.; Ando, T.; Lu, H.; Nakazawa, K.; Mayer, H.; Mochnal, G.

    2006-06-01

    Forging is a manufacturing process in which metal is pressed, pounded or squeezed under great pressure and, often, under high strain rates into high-strength parts known as forgings. The process is typically performed hot by preheating the metal to a desired temperature before it is worked. The forging process can create parts that are stronger than those manufactured by any other metal working process. Forgings are almost always used where reliability and human safety are critical. Forgings are normally component parts contained inside assembled items such airplanes, automobiles, tractors, ships, oil drilling equipment, engines missiles, and all kinds of capital equipment Forgings are stronger than castings and surpass them in predictable strength properties, producing superior strength that is assured, part to part.

  15. Migration pattern of cementless press fit cups in the presence of stabilizing screws in total hip arthroplasty

    PubMed Central

    2011-01-01

    The aim of this study was to evaluate the initial acetabular implant stability and late acetabular implant migration in press fit cups combined with screw fixation of the acetabular component in order to answer the question whether screws are necessary for the fixation of the acetabular component in cementless primary total hip arthroplasty. One hundred and seven hips were available for follow-up after primary THA using a cementless, porous-coated acetabular component. A total of 631 standardized radiographs were analyzed digitally by the "single-film-x-ray-analysis" method (EBRA). One hundred 'and one (94.4%) acetabular components did not show significant migration of more than 1 mm. Six (5.6%) implants showed migration of more than 1 mm. Statistical analysis did not reveal preoperative patterns that would identify predictors for future migration. Our findings suggest that the use of screw fixation for cementless porous- coated acetabular components for primary THA does not prevent cup migration. PMID:21486725

  16. Isothermal Roll Forging of T55 Compressor Blades

    DTIC Science & Technology

    1977-12-01

    with: (1) high strength at the blade forging temperature ; (2) good resistance to deformation and fracture when repeatedly cycled to the forging...feedstock, having lower room temperature strength, buckled under the same load resulting in only partial fill of the dies. The high force (6000 lb...Flash Control 16 3.1.5 Roll Forge Atmosphere 15 3.1.6 Roll Forge Lubricant 17 3.1.7 Temperature Control 17 3.2 Task 2 - Process Selection 18 3.3 Task

  17. 27 CFR 447.22 - Forgings, castings, and machined bodies.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ..., castings, extrusions, and machined bodies) which have reached a stage in manufacture where they are clearly... components, accessories, attachments and parts) then the particular forging, casting, extrusion,...

  18. 27 CFR 447.22 - Forgings, castings, and machined bodies.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ..., castings, extrusions, and machined bodies) which have reached a stage in manufacture where they are clearly... components, accessories, attachments and parts) then the particular forging, casting, extrusion,...

  19. 27 CFR 447.22 - Forgings, castings, and machined bodies.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ..., castings, extrusions, and machined bodies) which have reached a stage in manufacture where they are clearly... components, accessories, attachments and parts) then the particular forging, casting, extrusion,...

  20. 27 CFR 447.22 - Forgings, castings, and machined bodies.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ..., castings, extrusions, and machined bodies) which have reached a stage in manufacture where they are clearly... components, accessories, attachments and parts) then the particular forging, casting, extrusion,...

  1. 27 CFR 447.22 - Forgings, castings, and machined bodies.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ..., castings, extrusions, and machined bodies) which have reached a stage in manufacture where they are clearly... components, accessories, attachments and parts) then the particular forging, casting, extrusion,...

  2. 77 FR 23496 - Boundary Revision of Valley Forge National Historical Park

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-19

    ... National Park Service Boundary Revision of Valley Forge National Historical Park AGENCY: National Park... to the boundary of Valley Forge National Historical Park, pursuant to the authority specified below... ``Valley Forge National Historical Park Proposed Boundary Expansion, Montgomery County,...

  3. Titanium metals form direct bonding to bone after alkali and heat treatments.

    PubMed

    Nishiguchi, S; Kato, H; Fujita, H; Oka, M; Kim, H M; Kokubo, T; Nakamura, T

    2001-09-01

    In this article we evaluated the bone-bonding strengths of titanium and titanium alloy implants with and without alkali and heat treatments using the conventional canine femur push-out model. Four kinds of smooth cylindrical implants, made of pure titanium or three titanium alloys, were prepared with and without alkali and heat treatments. The implants were inserted hemitranscortically into canine femora. The bone-bonding shear strengths of the implants were measured using push-out test. At 4 weeks all types of the alkali- and heat-treated implants showed significantly higher bonding strength (2.4-4.5 MPa) than their untreated counterparts (0.3-0.6 MPa). At 12 weeks the bonding strengths of the treated implants showed no further increase, while those of the untreated implants had increased to 0.6-1.2MPa. Histologically, alkali- and heat-treated implants showed direct bonding to bony tissue without intervening fibrous tissue. On the other hand, untreated implants usually had intervening fibrous tissue at the interface between bone and the implant. The early and strong bonding to bone of alkali- and heat-treated titanium and its alloys without intervening fibrous tissue may be useful in establishing cementless stable fixation of orthopedic implants.

  4. Titanium Cranioplasty

    PubMed Central

    Gordon, D. S.; Blair, G. A. S.

    1974-01-01

    The technique of repairing defects of the skull with titanium is described. The skull contour can be accurately reproduced. The technique is simpler than wiring or suturing methods. The material is inert, radiolucent, and rigid. ImagesFIG. 1FIG. 2FIG. 3FIG. 5FIG. 6FIG. 7 PMID:4834099

  5. Fallon FORGE 3D Geologic Model

    SciTech Connect

    Doug Blankenship

    2016-03-01

    An x,y,z scattered data file for the 3D geologic model of the Fallon FORGE site. Model created in Earthvision by Dynamic Graphic Inc. The model was constructed with a grid spacing of 100 m. Geologic surfaces were extrapolated from the input data using a minimum tension gridding algorithm. The data file is tabular data in a text file, with lithology data associated with X,Y,Z grid points. All the relevant information is in the file header (the spatial reference, the projection etc.) In addition all the fields in the data file are identified in the header.

  6. West Flank Coso, CA FORGE Seismic Reflection

    SciTech Connect

    Doug Blankenship

    2016-05-16

    PDFs of seismic reflection profiles 101,110, 111 local to the West Flank FORGE site. 45 line kilometers of seismic reflection data are processed data collected in 2001 through the use of vibroseis trucks. The initial analysis and interpretation of these data was performed by Unruh et al. (2001). Optim processed these data by inverting the P-wave first arrivals to create a 2-D velocity structure. Kirchhoff images were then created for each line using velocity tomograms (Unruh et al., 2001).

  7. Preparation of the femoral bone cavity in cementless stems: broaching versus compaction

    PubMed Central

    Hjorth, Mette H; Stilling, Maiken; Søballe, Kjeld; Nielsen, Poul Torben; Christensen, Poul H; Kold, Søren

    2016-01-01

    Background and purpose — Short-term experimental studies have confirmed that there is superior fixation of cementless implants inserted with compaction compared to broaching of the cancellous bone. Patients and methods — 1-stage, bilateral primary THA was performed in 28 patients between May 2001 and September 2007. The patients were randomized to femoral bone preparation with broaching on 1 side and compaction on the other side. 8 patients declined to attend the postoperative follow-up, leaving 20 patients (13 male) with a mean age of 58 (36–70) years for evaluation. The patients were followed with radiostereometric analysis (RSA) at baseline, at 6 and 12 weeks, and at 1, 2, and 5 years, and measurements of periprosthetic bone mineral density (BMD) at baseline and at 1, 2, and 5 years. The subjective part of the Harris hip score (HHS) and details of complications throughout the observation period were obtained at a mean interval of 6.3 (3.0–9.5) years after surgery. Results — Femoral stems in the compaction group had a higher degree of medio-lateral migration (0.21 mm, 95% CI: 0.03–0.40) than femoral stems in the broaching group at 5 years (p = 0.02). No other significant differences in translations or rotations were found between the 2 surgical techniques at 2 years (p > 0.4) and 5 years (p > 0.7) postoperatively. There were no individual stems with continuous migration. Periprosthetic BMD in the 7 Gruen zones was similar at 2 years and at 5 years. Intraoperative femoral fractures occurred in 2 of 20 compacted hips, but there were none in the 20 broached hips. The HHS and dislocations were similar in the 2 groups at 6.3 (3.0–9.5) years after surgery. Interpretation — Bone compaction as a surgical technique with the Bi-Metric stem did not show the superior outcomes expected compared to conventional broaching. Furthermore, 2 periprosthetic fractures occurred using the compaction technique, so we cannot recommend compaction for insertion of the

  8. 17. Forge building, fuel storage shed, and foundry, 1906 Photocopied ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    17. Forge building, fuel storage shed, and foundry, 1906 Photocopied from a photograph by Thomas S. Bronson, 'Group at Whitney Factory, 5 November 1906,' NHCHSL. The most reliable view of the fuel storage sheds and foundry, together with a view of the forge building. - Eli Whitney Armory, West of Whitney Avenue, Armory Street Vicinity, Hamden, New Haven County, CT

  9. View west of small tooling and forging dies in Blacksmith ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View west of small tooling and forging dies in Blacksmith Shop, Boilermakers Department, east side of building 57; during World War II approximately forty women were employed as blacksmith's forging a variety of small tools; these may be the tools they used. - Naval Base Philadelphia-Philadelphia Naval Shipyard, Structure Shop, League Island, Philadelphia, Philadelphia County, PA

  10. 22 CFR 121.10 - Forgings, castings, and machined bodies.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 22 Foreign Relations 1 2014-04-01 2014-04-01 false Forgings, castings, and machined bodies. 121.10 Section 121.10 Foreign Relations DEPARTMENT OF STATE INTERNATIONAL TRAFFIC IN ARMS REGULATIONS THE UNITED STATES MUNITIONS LIST Enumeration of Articles § 121.10 Forgings, castings, and machined bodies. The...

  11. 18. INTERIOR VIEW OF ROUGH FORGED TOOLS (FOREGROUND) WHICH ARE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    18. INTERIOR VIEW OF ROUGH FORGED TOOLS (FOREGROUND) WHICH ARE PRE-HEATED IN THE FURNACE (REAR RIGHT) AND THEN FORGED WITH THE BRADLEY HAMMER (LEFT) AS SHOWN BY JAMES GLASPELL - Warwood Tool Company, Foot of Nineteenth Street, Wheeling, Ohio County, WV

  12. Biomechanical evaluation of adjunctive cerclage wire fixation for the prevention of periprosthetic femur fractures using cementless press-fit total hip replacement.

    PubMed

    Christopher, Scott A; Kim, Stanley E; Roe, Simon; Pozzi, Antonio

    2016-08-01

    Periprosthetic femoral fractures are a common complication associated with cementless press-fit total hip arthroplasty. The use of prophylactic cerclage wire fixation has been advocated to reduce this complication. The objective of this study was to evaluate whether a double loop cerclage wire, used as adjunctive fixation, increased the peak torsional load to failure in femora implanted with press-fit cementless stems. Peak torsional load to failure was compared between femora without adjunctive fixation and femora receiving a 1 mm double loop cerclage wire placed proximally to the lesser trochanter. Femora treated with adjunctive cerclage wire fixation failed at 20% greater peak torque (P = 0.0001). In conclusion, a double loop cerclage wire may aid in the prevention of periprosthetic fractures associated with press-fit cementless femoral stems.

  13. Long-term results using the straight tapered femoral cementless hip stem in total hip arthroplasty: a minimum of twenty-year follow-up.

    PubMed

    Ateschrang, Atesch; Weise, Kuno; Weller, Siegfried; Stöckle, Ulrich; de Zwart, Peter; Ochs, Björn Gunnar

    2014-08-01

    We report the first long-term results of a prospective cohort study after total hip arthroplasty using the cementless Bicontact hip stem. Between 1987 and 1990, 250 total hip arthroplasties in 236 patients were performed using the cementless Bicontact hip stem. The average follow-up was 22.8 years (20.4-24.8) and average age at index surgery was 58.1 years. Eighty-one patients died and 9 were lost to follow-up. We noted 11 stem revisions revealing an overall Kaplan Meier survival rate of 95.0% (CI 95%: 91.1-97.2%). The average Harris Hip Score revealed 81 points (range 24-93). The Bicontact hip stem demonstrated high survival rates despite high ages and osteopenic changes, which are equivalent to other long-term reports of cementless stem fixation.

  14. Low-temperature superplasticity of submicrocrystalline Ti-48Al-2Nb-2Cr alloy produced by multiple forging

    SciTech Connect

    Imayev, V.M.; Salishchev, G.A.; Shagiev, M.R.; Kuznetsov, A.V.; Imayev, R.M.; Senkov, O.N.; Froes, F.H.

    1998-12-18

    Gamma titanium aluminides are attractive for elevated temperature applications because of their high specific strength, modulus retention, good oxidation and creep resistance. However they are inherently brittle at temperatures below 600 C due to their strong covalent interatomic bonding, which makes fabrication difficult and has restricted commercial applications. In this research work the authors have studied superplastic (SP) forming of a gamma alloy. Grain refinement is the most common method of decreasing the temperature at which superplasticity is observed, while the second approach is applicable only to gamma alloys containing less than 47 at.% Al. In the present work, a low-temperature superplasticity of a gamma TiAl-based alloy was achieved by producing a submicrocrystalline structure via multistep forging. Mechanical behavior and microstructural evolution of the submicrocrystalline gamma titanium aluminide were studied and possible mechanisms of the low-temperature superplasticity were discussed.

  15. The use of a constrained cementless acetabular component for instability in total hip replacement.

    PubMed

    Rady, Ahmad Emad; Asal, Mohammed Kamal; Bassiony, Ayman Abdelaziz

    2010-01-01

    Recurrent dislocation after total hip arthroplasty is a disabling complication that can be difficult to treat. We evaluated the early clinical and radiographic outcome associated with the use of a constrained acetabular component for instability in total hip arthroplasty. Fifteen patients underwent either primary or revision total hip arthroplasty with a cementless constrained acetabular component for different indications. The mean patient age at surgery was 57.4 years and the mean clinical and radiological follow-up period was 26.4 months. Clinical assessment was performed by the Harris hip score and at the latest follow up patients reported outcome using the Oxford hip score questionnaire. All radiographs were evaluated for evidence of loosening. Only one patient experienced redislocation with the constrained prosthesis. The average Harris hip score increased from a preoperative mean of 22 (range, 16 - 36) to a postoperative mean of 85 (range, 66-94). Preoperatively, the mean Oxford Hip Score was 48.6, which decreased to 20.5 at the final examination. All but one of the 15 hips had a well-fixed, stable cup. Femoral component stability with bone ingrowth was achieved in 10 cases. A constrained acetabular component is an effective option for the treatment of hip instability in primary and revision arthroplasty in those at high risk of dislocation. The potential for aseptic loosening requires evaluation by long term studies.

  16. Fabrication of low-cost, cementless femoral stem 316L stainless steel using investment casting technique.

    PubMed

    Baharuddin, Mohd Yusof; Salleh, Sh-Hussain; Suhasril, Andril Arafat; Zulkifly, Ahmad Hafiz; Lee, Muhammad Hisyam; Omar, Mohd Afian; Abd Kader, Ab Saman; Mohd Noor, Alias; A Harris, Arief Ruhullah; Abdul Majid, Norazman

    2014-07-01

    Total hip arthroplasty is a flourishing orthopedic surgery, generating billions of dollars of revenue. The cost associated with the fabrication of implants has been increasing year by year, and this phenomenon has burdened the patient with extra charges. Consequently, this study will focus on designing an accurate implant via implementing the reverse engineering of three-dimensional morphological study based on a particular population. By using finite element analysis, this study will assist to predict the outcome and could become a useful tool for preclinical testing of newly designed implants. A prototype is then fabricated using 316L stainless steel by applying investment casting techniques that reduce manufacturing cost without jeopardizing implant quality. The finite element analysis showed that the maximum von Mises stress was 66.88 MPa proximally with a safety factor of 2.39 against endosteal fracture, and micromotion was 4.73 μm, which promotes osseointegration. This method offers a fabrication process of cementless femoral stems with lower cost, subsequently helping patients, particularly those from nondeveloped countries.

  17. Metallosis with pseudotumour formation: Long-term complication following cementless total hip replacement in a dog

    PubMed Central

    Volstad, Nicola J.; Schaefer, Susan L.; Snyder, Laura A.; Meinen, Jeffrey B.; Sample, Susannah J.

    2017-01-01

    Summary Case description A 10-year-old female Belgian Teruven dog was presented to our clinic for total hip revision following a diagnosis of implant (cup) failure with metallosis and abdominal pseudotumour formation. The patient had a cementless metal-on-polyethylene total hip replacement performed nine years prior to presentation. Clinical findings The clinical findings, including pseudotumour formation locally and at sites distant from the implant and pain associated with the joint replacement, were similar to those described in human patients with this condition. Histopathological, surgical, and radiographic findings additionally supported the diagnosis of metallosis and pseudotumour formation. Treatment and outcome Distant site pseudo tumours were surgically removed and the total hip replacement was explanted due to poor bone quality. The patient recovered uneventfully and has since resumed normal activity. Conclusion In veterinary patients with metal-on-polyethylene total hip implants, cup failure leading to metallosis and pseudotumour formation should be considered as a potential cause of ipsilateral hindlimb lameness, intra-pelvic abdominal tumours, or a combination of both. These clinical findings may occur years after total hip replacement surgery. PMID:27189390

  18. Processing and structure of high-energy-rate-forged 21-6-9 and 304L forgings

    SciTech Connect

    Mataya, M.C.; Carr, M.J.; Krenzer, R.W.; Krauss, G.

    1981-08-10

    Two 304L and three Nitronic 40 (21-6-9) high energy rate processed forgings were studied to determine interrelationships that exist between forging history, mechanical properties, microstructure, macrostructure, and substructure. A striking observation is the wide variation in properties and structure between different forgings and also between different locations within an individual forging. Variations were related to either finishing temperature of the last forming stage or to the forming sequence. For example, lower finishing temperatures resulted in higher dislocation densities and therefore higher strengths. Higher finishing temperatures promoted dynamic recrystallization, lower dislocation densities, and lower strengths. With respect to forming sequence, locations in the forging which are formed first undergo a number of additional thermal cycles while the rest of the part is being formed. These areas are usually recrystallized and have lower dislocation densities, and therefore lower strengths relative to locations formed later in the sequence.

  19. Preparation of titanium diboride powder

    DOEpatents

    Brynestad, Jorulf; Bamberger, Carlos E.

    1985-01-01

    Finely-divided titanium diboride or zirconium diboride powders are formed by reacting gaseous boron trichloride with a material selected from the group consisting of titanium powder, zirconium powder, titanium dichloride powder, titanium trichloride powder, and gaseous titanium trichloride.

  20. Metal Bonded Titanium Diboride

    DTIC Science & Technology

    1952-03-01

    of specimens made from titanium diboride plus 10 percent titanium and 30 percent zirconium . X 100. 22 6. Microstructures of specimens made from...chromium. X 1000 26 10. Microstructures of specimens made from titanium diboride plus 10 percent titanium and 30 percent zirconium . X 1200 27 11. Gain in...shock resistance and oxidation resistance of titanium diboride but zirconium diboride which is isomorphous with titanium diboride has been reported6

  1. A Multicenter Approach Evaluating the Impact of Vitamin E-Blended Polyethylene in Cementless Total Hip Replacement

    PubMed Central

    Jäger, Marcus; van Wasen, Andrea; Warwas, Sebastian; Landgraeber, Stefan; Haversath, Marcel; Group, VITAS

    2014-01-01

    Since polyethylene is one of the most frequently used biomaterials as a liner in total hip arthroplasty, strong efforts have been made to improve design and material properties over the last 50 years. Antioxidants seems to be a promising alternative to further increase durability and reduce polyethylene wear in long term. As of yet, only in vitro results are available. While they are promising, there is yet no clinical evidence that the new material shows these advantages in vivo. To answer the question if vitamin-E enhanced ultra-high molecular weight polyethylene (UHMWPE) is able to improve long-term survivorship of cementless total hip arthroplasty we initiated a randomized long-term multicenter trial. Designed as a superiority study, the oxidation index assessed in retrieval analyses of explanted liners was chosen as primary parameter. Radiographic results (wear rate, osteolysis, radiolucency) and functional outcome (Harris Hip Scores, University of California-Los Angeles, Hip Disability and Osteoarthritis Outcome Score, Visual Analogue Scale) will serve as secondary parameters. Patients with the indication for a cementless total hip arthroplasty will be asked to participate in the study and will be randomized to either receive a standard hip replacement with a highly cross-linked UHMWPE-X liner or a highly cross-linked vitamin-E supplemented UHMWPE-XE liner. The follow-up will be 15 years, with evaluation after 5, 10 and 15 years. The controlled randomized study has been designed to determine if Vitamin-E supplemented highly cross-linked polyethylene liners are superior to standard XLPE liners in cementless total hip arthroplasty. While several studies have been started to evaluate the influence of vitamin-E, most of them evaluate wear rates and functional results. The approach used for this multicenter study, to analyze the oxidation status of retrieved implants, should make it possible to directly evaluate the ageing process and development of the implant

  2. Cementless modular hip arthroplasty as a salvage operation for failed internal fixation of trochanteric fractures in elderly patients.

    PubMed

    Laffosse, Jean-Michel; Molinier, François; Tricoire, Jean-Louis; Bonnevialle, Nicolas; Chiron, Philippe; Puget, Jean

    2007-12-01

    Failure of internal fixation of trochanteric fractures requires repeat surgery in order to avoid the risks of complications affecting bedridden patients. This study was conducted to assess the results of hemi- or total hip arthroplasty with a cementless modular femoral stem, as a salvage operation following early mechanical failure of internal fixation. Twenty nine patients with a mean age of 81.1 years (70-91) were included in the study. Fractures extending into the diaphysis and pathological fractures were excluded, as well as patients who presented late complications. A cementless modular stem designed for metaphyso-diaphyseal anchorage was used in all cases. Twenty-two patients underwent hemiarthroplasty and seven total hip arthroplasty. Four patients died within one year and two were lost to follow-up. The remaining 23 patients were followed for a mean of 20 months (range: 6-89). At the time of last follow-up, 20 were ambulatory with (11 cases) or without support (9 cases) and three were bedridden. There were no intra- or postoperative femoral fractures. Two patients presented an early dislocation after bipolar hemiarthroplasty. One was successfully treated by closed reduction; the other underwent revision with a dual mobility acetabular component because of recurrent dislocation. All the patients reported significant pain relief and functional improvement. Subsidence of the stem greater than 5 mm was noted in three cases, without clinical consequences. The cementless modular femoral stem used in this study appeared as a reliable implant. Primary arthroplasty with such an implant could be considered in selected cases such as markedly unstable fractures and in osteoporotic elderly patients.

  3. Effect of femoral canal shape on mechanical stress distribution and adaptive bone remodelling around a cementless tapered-wedge stem

    PubMed Central

    Oba, M.; Kobayashi, N.; Ike, H.; Tezuka, T.; Saito, T.

    2016-01-01

    Objectives In total hip arthroplasty (THA), the cementless, tapered-wedge stem design contributes to achieving initial stability and providing optimal load transfer in the proximal femur. However, loading conditions on the femur following THA are also influenced by femoral structure. Therefore, we determined the effects of tapered-wedge stems on the load distribution of the femur using subject-specific finite element models of femurs with various canal shapes. Patients and Methods We studied 20 femurs, including seven champagne flute-type femurs, five stovepipe-type femurs, and eight intermediate-type femurs, in patients who had undergone cementless THA using the Accolade TMZF stem at our institution. Subject–specific finite element (FE) models of pre- and post-operative femurs with stems were constructed and used to perform FE analyses (FEAs) to simulate single-leg stance. FEA predictions were compared with changes in bone mineral density (BMD) measured for each patient during the first post-operative year. Results Stovepipe models implanted with large-size stems had significantly lower equivalent stress on the proximal-medial area of the femur compared with champagne-flute and intermediate models, with a significant loss of BMD in the corresponding area at one year post-operatively. Conclusions The stovepipe femurs required a large-size stem to obtain an optimal fit of the stem. The FEA result and post-operative BMD change of the femur suggest that the combination of a large-size Accolade TMZF stem and stovepipe femur may be associated with proximal stress shielding. Cite this article: M. Oba, Y. Inaba, N. Kobayashi, H. Ike, T. Tezuka, T. Saito. Effect of femoral canal shape on mechanical stress distribution and adaptive bone remodelling around a cementless tapered-wedge stem. Bone Joint Res 2016;5:362–369. DOI: 10.1302/2046-3758.59.2000525. PMID:27601435

  4. A multicenter approach evaluating the impact of vitamin e-blended polyethylene in cementless total hip replacement.

    PubMed

    Jäger, Marcus; van Wasen, Andrea; Warwas, Sebastian; Landgraeber, Stefan; Haversath, Marcel; Group, Vitas

    2014-04-22

    Since polyethylene is one of the most frequently used biomaterials as a liner in total hip arthroplasty, strong efforts have been made to improve design and material properties over the last 50 years. Antioxidants seems to be a promising alternative to further increase durability and reduce polyethylene wear in long term. As of yet, only in vitro results are available. While they are promising, there is yet no clinical evidence that the new material shows these advantages in vivo. To answer the question if vitamin-E enhanced ultra-high molecular weight polyethylene (UHMWPE) is able to improve long-term survivorship of cementless total hip arthroplasty we initiated a randomized long-term multicenter trial. Designed as a superiority study, the oxidation index assessed in retrieval analyses of explanted liners was chosen as primary parameter. Radiographic results (wear rate, osteolysis, radiolucency) and functional outcome (Harris Hip Scores, University of California-Los Angeles, Hip Disability and Osteoarthritis Outcome Score, Visual Analogue Scale) will serve as secondary parameters. Patients with the indication for a cementless total hip arthroplasty will be asked to participate in the study and will be randomized to either receive a standard hip replacement with a highly cross-linked UHMWPE-X liner or a highly cross-linked vitamin-E supplemented UHMWPE-XE liner. The follow-up will be 15 years, with evaluation after 5, 10 and 15 years. The controlled randomized study has been designed to determine if Vitamin-E supplemented highly cross-linked polyethylene liners are superior to standard XLPE liners in cementless total hip arthroplasty. While several studies have been started to evaluate the influence of vitamin-E, most of them evaluate wear rates and functional results. The approach used for this multicenter study, to analyze the oxidation status of retrieved implants, should make it possible to directly evaluate the ageing process and development of the implant

  5. New titanium and titanium/hydroxyapatite coatings on ultra-high-molecular-weight polyethylene-in vitro osteoblastic performance.

    PubMed

    Silva, M A; Gomes, P S; Vila, M; Lopes, M A; Santos, J D; Silva, R F; Fernandes, M H

    2010-06-01

    The development of optimized hip joint materials is one of the most challenging opportunities in prosthetic technologies. In current approaches, ultra-high-molecular-weight polyethylene(UHMWPE) has been a favorite material for the acetabular component and, regarding the cementless technique, several coating options may be considered to contain and stabilize bearing surfaces and establish an improved interface with bone. In this work, newly developed constructs of UHMWPE coated with either commercially pure titanium (cpTi-UHMWPE), by DC magnetron sputtering, or with commercially pure titanium and hydroxyapatite(cpTi/HA-UHMWPE), by DC/RF magnetron co-sputtering, have been prepared and biologically characterized with human bone marrow-derived osteoblastic cultures. The cpTi-UHMWPE samples allowed a high cell growth and the expression of the complete osteoblastic phenotype, with high alkaline phosphatase activity, expression of osteogenic-associated genes and evident cell-mediated mineralization of the extracellular matrix. In comparison, the cpTi/HA-UHMWPE samples reported lower cell proliferation but earlier cell-mediated matrix mineralization. Accordingly, these newly developed systems maybe suitable candidates to improve the osteointegration process in arthroplastic devices;nevertheless, further biological evaluation should be conducted.

  6. Initial billet and forging dies shape optimization: Application on an axisymetrical forging with a hammer

    NASA Astrophysics Data System (ADS)

    Meng, Fanjuan; Labergere, Carl; Lafon, Pascal

    2011-05-01

    In metal forming process, the forging die design is the most important step for products quality control. Reasonable dies shape can not only reduce raw material cost but also improving material flow and eliminating defects. The main objective of this paper is to obtain some optimal parameters of the initial billet and forging dies shape according to the simulation results of a two-step metal forming process (platting step and forging step). To develop this metal forming process optimization system several numerical tools are required: geometric modelling (CATIA V5™), FEM analysis (ABAQUS®), work-flow control and optimization computation (MODEFRONTIER®). This study is done in three stages: simulating the two-step metal forming process, building surrogate meta-models to relate response and variables and optimizing the process by using advanced optimization algorithms. In this paper, a two-step axisymmetric metal forming project was studied as an example. By using our simulation model, we get 581 correct real simulation results totally. According to all these real values, we build the surrogate meta-models and obtain Pareto points for a two-objective optimization process. The choice of a solution in all Pareto points will be done by the engineer who can choose his best values according to their criterions of project.

  7. Osseointegration into a Novel Titanium Foam Implant in the Distal Femur of a Rabbit

    PubMed Central

    Willie, Bettina M.; Yang, Xu; Kelly, Natalie H.; Merkow, Justin; Gagne, Shawn; Ware, Robin; Wright, Timothy M.; Bostrom, Mathias P.G.

    2010-01-01

    A novel porous titanium foam implant has recently been developed to enhance biological fixation of orthopaedic implants to bone. The aim of this study was to examine the mechanical and histological characteristics of bone apposition into two different pore sizes of this titanium foam (565 and 464 micron mean void intercept length) and to compare these characteristics to those obtained with a fully porous conventionally sintered titanium bead implant. Cylindrical implants were studied in a rabbit distal femoral intramedullary osseointegration model at time zero and at 3, 6, and 12 weeks. The amount of bone ingrowth, amount of periprosthetic bone, and mineral apposition rate of periprosthetic bone measured did not differ among the three implant designs at 3, 6, or 12 weeks. By 12 weeks, the interface stiffness and maximum load of the beaded implant was significantly greater than either foam implant. No significant difference was found in the interface stiffness or maximum load between the two foam implant designs at 3, 6, or 12 weeks. The lower compressive modulus of the foam compared to the more dense sintered beaded implants likely contributed to the difference in failure mode. However, the foam implants have a similar compressive modulus to other clinically successful coatings, suggesting they are nonetheless clinically adequate. Additional studies are required to confirm this in weight-bearing models. Histological data suggest that these novel titanium foam implants are a promising alternative to current porous coatings and should be further investigated for clinical application in cementless joint replacement. PMID:20024964

  8. 6. NORTH END OF MACHINE SHOP. FORGE SHOP (HAER No. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. NORTH END OF MACHINE SHOP. FORGE SHOP (HAER No. CA-326-K) ON LEFT, FORD PLANT IN DISTANCE, NE BY 60. - Rosie the Riveter National Historical Park, Machine Shop, 1311 Canal Boulevard, Richmond, Contra Costa County, CA

  9. View facing east of top of quarry wall with forge ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View facing east of top of quarry wall with forge site in foreground - Granite Hill Plantation, Quarry No. 4, South side of State Route 16, 1.3 miles northeast east of Sparta, Sparta, Hancock County, GA

  10. DETAIL VIEW OF BLACKSMITH'S FORGE AND WORK AREA ON WEST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL VIEW OF BLACKSMITH'S FORGE AND WORK AREA ON WEST SIDE OF UPPER TRAM TERMINAL, LOOKING EAST. FORGE IS IN FOREGROUND, WITH THE ANVIL BLOCK JUST TO THE RIGHT AND BEHIND IT. A TRAM CAR IS UPSIDE DOWN TO THE LEFT OF THE FORGE. THE PIPE GOING INTO THE FORGE ON THE RIGHT CARRIED COMPRESSED AIR TO BLOW THE COALS. AT CENTER RIGHT ON THE TRAM TERMINAL ARE THE OPENING AND CLOSING MECHANISMS FOR THE ORE BUCKETS. AT CENTER LEFT IS A BRAKE WHEEL. THE ANCHOR POINTS FOR THE STATIONARY TRAM CABLES ARE JUST BELOW THIS WHEEL. THE FRONT END OF THE TERMINAL IS JUST OFF FRAME ON THE RIGHT. - Keane Wonder Mine, Park Route 4 (Daylight Pass Cutoff), Death Valley Junction, Inyo County, CA

  11. [Joint prostheses components of warm-forged and surface treated Ti-6Al-7Nb alloy].

    PubMed

    Semlitsch, M; Weber, H; Streicher, R M; Schön, R

    1991-05-01

    In 1978 development of a TiAl alloy with the inert alloying element niobium was initiated. In 1984, the optimal composition was found to be Ti-6Al-7Nb (Protasul-100). This custom-made alloy for implants has the same alpha/beta micro-structure and equally good mechanical properties as Ti-6Al-4V. The corrosion resistance of Ti-6Al-7Nb is better than that of pure titanium and Ti-6Al-4V, due to the very dense and stable passive layer. Since 1985, highly stressed anchoring stems of various hip prosthesis designs have been manufactured from hot-forged Ti-6Al-7Nb/Protasul-100. Polished surfaces of hip, knee or wrist joints made of Ti-6Al-7Nb intended to articulate with polyethylene are surface-treated by the application of a very hard, 3-5 microns thick titanium nitride coating (Tribosul-TiN), or by oxygen diffusion hardening (Tribosul-ODH) to a depth of 30 microns.

  12. Sports and physical activity after cementless total hip arthroplasty with a minimum follow-up of 10 years.

    PubMed

    Innmann, M M; Weiss, S; Andreas, F; Merle, C; Streit, M R

    2016-05-01

    The present retrospective cohort study was conducted to compare sporting activity levels before and a minimum of 10 years after primary cementless total hip arthroplasty (THA). A consecutive series of 86 patients with a mean age at surgery of 52 years (range, 21-60 years) was evaluated 11 years after surgery (range, 10-12 years). Pre- and post-operative sporting activities were assessed at routine follow-up using the University of California, Los Angeles activity score and the Schulthess Clinic sports and activity questionnaire. Post-operative health-related quality of life was measured using the Short-Form 36 (SF-36) questionnaire and compared with age-matched reference populations from the SF-36 database. Eleven years after THA, 89% of preoperatively active patients had returned to sport. Comparing sports activity preoperatively (before the onset of symptoms) and 11 years after THA, no significant difference was found for the mean number of disciplines or session length. A significant decline in high-impact activities was observed, while participation in low-impact activities significantly increased. Health-related quality of life compared well against a healthy age-matched reference population and was significantly higher than in a reference group of patients with osteoarthritis. The majority of patients were able to maintain their physical activity level in the long term after primary cementless THA, compared with the activity level before the onset of restricting osteoarthritis symptoms. However, a change in disciplines toward low-impact activities was observed.

  13. Hydriding of Titanium.

    DTIC Science & Technology

    1998-03-01

    hole. The metals used to make these couples with titanium included HY80 steel , 316 stainless steel , five-nines aluminum, 6061 aluminum, and zinc. All...the other surfaces. Titanium Coupled With Other Metals The corrosion potentials of grade 2 titanium galvanically coupled with naval brass, HY80 steel ...2 titanium; naval brass caused titanium to become an anode. At room temperature, HY80 steel and 316 stainless steel couples exhibited corrosion

  14. Snake River Plain FORGE Site Characterization Data

    SciTech Connect

    Robert Podgorney

    2016-04-18

    The site characterization data used to develop the conceptual geologic model for the Snake River Plain site in Idaho, as part of phase 1 of the Frontier Observatory for Research in Geothermal Energy (FORGE) initiative. This collection includes data on seismic events, groundwater, geomechanical models, gravity surveys, magnetics, resistivity, magnetotellurics (MT), rock physics, stress, the geologic setting, and supporting documentation, including several papers. Also included are 3D models (Petrel and Jewelsuite) of the proposed site. Data for wells INEL-1, WO-2, and USGS-142 have been included as links to separate data collections. These data have been assembled by the Snake River Geothermal Consortium (SRGC), a team of collaborators that includes members from national laboratories, universities, industry, and federal agencies, lead by the Idaho National Laboratory (INL). Other contributors include the National Renewable Energy Laboratory (NREL), Lawrence Livermore National Laboratory (LLNL), the Center for Advanced Energy Studies (CEAS), the University of Idaho, Idaho State University, Boise State University, University of Wyoming, University of Oklahoma, Energy and Geoscience Institute-University of Utah, US Geothermal, Baker Hughes Campbell Scientific Inc., Chena Power, US Geological Survey (USGS), Idaho Department of Water Resources, Idaho Geological Survey, and Mink GeoHydro.

  15. West Flank Coso, CA FORGE Magnetotelluric Inversion

    DOE Data Explorer

    Doug Blankenship

    2016-05-16

    The Coso Magnetotelluric (MT) dataset of which the West Flank FORGE MT data is a subset, was collected by Schlumberger / WesternGeco and initially processed by the WesternGeco GeoSolutions Integrated EM Center of Excellence in Milan, Italy. The 2011 data was based on 99 soundings that were centered on the West Flank geothermal prospect. The new soundings along with previous data from 2003 and 2006 were incorporated into a 3D inversion. Full impedance tensor data were inverted in the 1-3000 Hz range. The modelling report notes several noise sources, specifically the DC powerline that is 20,000 feet west of the survey area, and may have affected data in the 0.02 to 10 Hz range. Model cell dimensions of 450 x 450 x 65 feet were used to avoid computational instability in the 3D model. The fit between calculated and observed MT values for the final model run had an RMS value of 1.807. The included figure from the WesternGeco report shows the sounding locations from the 2011, 2006 and 2003 surveys.

  16. Computational modeling in the primary processing of titanium: A review

    NASA Astrophysics Data System (ADS)

    Venkatesh, Vasisht; Wilson, Andrew; Kamal, Manish; Thomas, Matthew; Lambert, Dave

    2009-05-01

    Process modeling is increasingly becoming a vital tool for modern metals manufacturing. This paper reviews process modeling initiatives started at TIMET over the last decade for the primary processing of titanium alloys. SOLAR, a finite volume-based numerical model developed at the Ecole de Mine at Nancy, has been successfully utilized to optimize vacuum arc remelting process parameters, such as electromagnetic stirring profiles in order to minimize macrosegregation and improve ingot quality. Thermo-mechanical modeling of heat treating, billet forging, and slab rolling is accomplished via the commercial finite element analysis model, DEFORM, to determine heating times, cooling rates, strain distributions, etc.

  17. Cementless total hip arthroplasty in patients with ankylosing spondylitis: A retrospective observational study.

    PubMed

    Xu, Jun; Zeng, Min; Xie, Jie; Wen, Ting; Hu, Yihe

    2017-01-01

    Controversies on the surgical protocols and efficacies of total hip arthroplasty (THA) in ankylosing spondylitis (AS) still exist. The aim of this study was to retrospectively analyze the perioperative managements and their outcomes related to performing THA on patients with AS.Data of 54 AS patients who underwent 81 THAs between 2008 and 2014 were retrospectively analyzed. Clinical and imaging data were collected preoperatively, postoperatively, and during the follow-up period for surgical efficacy.Using posterolateral approach, cementless prostheses were selected in all cases. Mean follow-up period was 3.6 years (range, 2-8 years). Inclinations and anteversions of acetabular cups were 36.3°±4.5° (range, 30°-50°) and 12.3°±4.9° (range, 0°-25°) respectively. Mean visual analog scale (VAS) score decreased from 6.7 ± 2.1 (range, 4-10) preoperatively to 1.5 ± 1.0 (range, 0-4) at final follow-up, and mean Harris hip score (HHS) improved from 31.2 ± 11.6 (range, 15-45) to 86.1 ± 4.3 (range, 80-95) (P < 0.05). Postoperative range of motion (ROM) in flexion was improved from 6.7°±13.5° (range, 0°-50°) preoperatively to 82.5°±6.4° (range, 70°-100°) at final follow-up, and ROM in extension was improved from 1.8°±5.7°(range, 0°-15°) to 15.4°±2.6° (range, 10°-20°) (P < 0.05). Heterotopic ossification (HO) was documented in 9 hips (11.1%). Signs of stable fibrous ingrowth and bone ingrowth were detected in 52 and 29 hips, respectively. Sciatic never injury was occurred in 3 cases, and treated conservatively. There were no signs of periprosthetic fractures, dislocation, or prosthesis loosening.Surgical efficacies of THA for AS patients with severe hip involvement are satisfactory.

  18. Bioresorbable devices made of forged composites of hydroxyapatite (HA) particles and poly L-lactide (PLLA). Part II: practical properties of miniscrews and miniplates.

    PubMed

    Shikinami, Y; Okuno, M

    2001-12-01

    Miniscrews and miniplates made of forged composites composed of raw hydroxyapatite (u-HA) particles (particle size 0.2-20 microm, averaging 3.0 microm, Ca/p = 1.69 and containing CO3(2-)) and a poly L-lactide (PLLA, Mv: about 180 kDa, containing residual 0.05 wt% lactide) with osteological bioactivity such as direct bonding to bone and osteoconductivity, total resorbability and radiopacity were examined for various mechanical properties in order to evaluate their usefulness for cranio-, oral and maxillo-facial as well as plastic and reconstructive surgeries with PLLA-only or titanium devices. The composites containing u-HA particles at 30wt% for miniscrews and 40wt% for miniplates were selected based on total mechanical strengths and bioactivity, respectively. It was found that the composite devices generally had slightly different mechanical properties than forged PLLA-only devices of which strengths are ranked the highest among the reinforced PLLA-only ones that having been used in many clinical cases to date, in spite of their approximate 2 or 3 times lower absolute strengths than those of titanium ones. However, a remarkable distinction that makes the composite miniplates stand above the titanium ones was confirmed on their fatigue resistance to alternate bendings such that they retained 70% of their initial strength even after 60 times without revealing any damage, whereas the metallic devices fully broke off at only 8 times. This behavior was similar to that of forged PLLA-only devices but is unique as composites made of organic polymers divided by inorganic particles. In addition, profile plates such as L-, T-, X, T, C-, Mesh-, Box-, and Barhole types which were processed by forging twice exhibited nearly directional isotropy in strength and could be deformed in situ at ordinary temperatures to adjust their shapes along the surface undulations of the skull, mandible, maxilla, zygomatic bone and the like without thermoforming and did not return to their

  19. Joint replacement components made of hot-forged and surface-treated Ti-6Al-7Nb alloy.

    PubMed

    Semlitsch, M F; Weber, H; Streicher, R M; Schön, R

    1992-01-01

    We have developed a titanium-aluminium alloy with the inert alloying element niobium. The optimal composition was found to be Ti-6Al-7Nb (Protasul-100). This custom-made alloy designed for implants shows the same alpha/beta structure as Ti-6Al-4V and exhibits equally good mechanical properties. The corrosion resistance of Ti-6Al-7Nb in sodium chloride solution is equivalent to that of pure titanium and Ti-6Al-4V. This is due to a very dense and stable passive layer. Highly stressed anchorage stems of different hip prosthesis designs have been made from hot-forged Ti-6Al-7Nb. The polished surfaces of hip, knee and wrist joints made of Ti-6Al-7Nb and articulating against polyethylene are surface-treated by means of a very hard and 3-5 microns thick titanium nitride coating (Tribosul-TiN) or by oxygen diffusion hardening (Tribosul-ODH) to a depth of 30 microns.

  20. The Harris-Galante cementless acetabular component: results in 190 cases with at least 3 years follow-up.

    PubMed

    Claus, B; Van Innis, B; De Witte, E; Van Overschelde, J; Magotteaux, B; Fatemi, F; Vandepaer, F

    1993-01-01

    The results of 190 primary total hip arthroplasties with a Harris-Galante cementless acetabular cup were reviewed. All patients had a minimum follow-up of 3 years (range, 3 to 5.5 years, mean 46 months). Clinical and radiographical analysis was performed. Inguinal pain was recorded in five cases. We noted a fracture of a screw in four cases without further implications. There was no evidence of acetabular loosening. There was no migration of the acetabular cup. No acetabular component showed measurable wear of the polyethylene liner. Non-progressive radiolucent lines were recorded in 14% of the patients: among these patients, radiolucent lines were noted in zone 1 in 46%, in zone 2 in 4% and in zone 3 in 86%. Two socket revisions became necessary. One patient suffered a deep-seated infection. Another revision was necessary because of recurrent dislocation.

  1. Titanium hermetic seals

    DOEpatents

    Brow, Richard K.; Watkins, Randall D.

    1995-01-01

    Titanium is prenitrided by being heated in a nitrogen environment under conditions which give rise to the formation of a titanium-nitride surface layer on the titanium. Titanium thus prenitrided may be used in electrical components which are hermetically sealed using silicate glasses and standard glass sealing techniques. According to the method of the invention, alkali volatilization and formation of deleterious interfacial silicide are inhibited.

  2. Titanium hermetic seals

    DOEpatents

    Brow, Richard K.; Watkins, Randall D.

    1995-07-04

    Titanium is prenitrided by being heated in a nitrogen environment under conditions which give rise to the formation of a titanium-nitride surface layer on the titanium. Titanium thus prenitrided may be used in electrical components which are hermetically sealed using silicate glasses and standard glass sealing techniques. According to the method of the invention, alkali volatilization and formation of deleterious interfacial silicide are inhibited.

  3. Prediction of Microstructure in High-Strength Ductile Forging Parts

    SciTech Connect

    Urban, M.; Back, A.; Hirt, G.; Keul, C.; Bleck, W.

    2010-06-15

    Governmental, environmental and economic demands call for lighter, stiffer and at the same time cheaper products in the vehicle industry. Especially safety relevant parts have to be stiff and at the same time ductile. The strategy of this project was to improve the mechanical properties of forging steel alloys by employing a high-strength and ductile bainitic microstructure in the parts while maintaining cost effective process chains to reach these goals for high stressed forged parts. Therefore, a new steel alloy combined with an optimized process chain has been developed. To optimize the process chain with a minimum of expensive experiments, a numerical approach was developed to predict the microstructure of the steel alloy after the process chain based on FEM simulations of the forging and cooling combined with deformation-time-temperature-transformation-diagrams.

  4. Sealing glasses for titanium and titanium alloys

    DOEpatents

    Brow, Richard K.; Watkins, Randall D.

    1992-01-01

    Glass compositions containing CaO, Al.sub.2 O.sub.3, B.sub.2 O.sub.3, SrO and BaO of various combinations of mole % are provided. These compositions are capable of forming stable glass-to-metal seals with titanium and titanium alloys, for use in components such as seals for battery headers.

  5. Sealing glasses for titanium and titanium alloys

    DOEpatents

    Brow, R.K.; Watkins, R.D.

    1988-01-21

    Glass compositions containing CaO, Al/sub 2/O/sub 3/, B/sub 2/O/sub 3/, SrO and BaO of various combinations of mole % are provided. These compositions are capable of forming stable glass-to-metal seals with titanium and titanium alloys, for use in components such as seals for battery headers.

  6. West Flank Coso FORGE Magnetotelluric 3D Data

    SciTech Connect

    Doug Blankenship

    2016-01-01

    This is the 3D version of the MT data for the West Flank FORGE area.The Coso geothermal field has had three Magnetotelluric (MT) datasets collected including surveys in 2003, 2006, and 2011. The final collection, in 2011, expanded the survey to the west and covers the West Flank of FORGE area.This most recent data set was collected by Schlumberger/WesternGeco and inverted by the WesternGeco GeoSolutions Integrated EM Center of Excellence in Milan, Italy; the 2003 and 2006 data were integrated for these inversions in the present study.

  7. Influence of free forging conditions on austenitic grain growth in constructional steel

    NASA Astrophysics Data System (ADS)

    Zagulyaeva, S. V.; Potanina, V. S.; Vinograd, M. I.

    1984-02-01

    The initial period of austenitic grain growth in heating of a hot forged billet of 50G-SSh steel and of forgings after free forging is characterized by the formation of a mixed grain structure of No. 8 fine grains and No. 3-0 coarse.

  8. 77 FR 14445 - Application for a License To Export Steel Forging

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-09

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Application for a License To Export Steel Forging Pursuant to 10 CFR 110.70(b) ``Public Notice of... Spain. December 15, 2011 head steel head steel February 7, 2012 forging. forging will be XR175...

  9. Modelling of the radial forging process of a hollow billet with the mandrel on the lever radial forging machine

    NASA Astrophysics Data System (ADS)

    Karamyshev, A. P.; Nekrasov, I. I.; Pugin, A. I.; Fedulov, A. A.

    2016-04-01

    The finite-element method (FEM) has been used in scientific research of forming technological process modelling. Among the others, the process of the multistage radial forging of hollow billets has been modelled. The model includes both the thermal problem, concerning preliminary heating of the billet taking into account thermal expansion, and the deformation problem, when the billet is forged in a special machine. The latter part of the model describes such features of the process as die calibration, die movement, initial die temperature, friction conditions, etc. The results obtained can be used to define the necessary process parameters and die calibration.

  10. Family Health and Financial Literacy--Forging the Connection

    ERIC Educational Resources Information Center

    Braun, Bonnie; Kim, Jinhee; Anderson, Elaine A.

    2009-01-01

    Families are at-risk of or experiencing a diminished quality of living and life in current economic times and difficult decisions are required. Health and financial literacy are the basis for wise personal and public decision making. Family and consumer sciences (FCS) professionals can forge connections between health and financial literacy to…

  11. 16. Forge building and fuel storage shed from the southwest, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. Forge building and fuel storage shed from the southwest, c.1918 Photocopied from a photograph in the collection of William F. Applegate, 43 Grandview Avenue, Wallingford, Connecticut. - Eli Whitney Armory, West of Whitney Avenue, Armory Street Vicinity, Hamden, New Haven County, CT

  12. Electronic Portfolios in Teacher Education: Forging a Middle Ground

    ERIC Educational Resources Information Center

    Strudler, Neal; Wetzel, Keith

    2012-01-01

    At a time when implementation of electronic portfolios (EPs) is expanding, the issues of clarifying their purposes continue to plague teacher education programs. Are student-centered uses of EPs compatible with program assessment and accreditation efforts? Is this an either/or situation, or can a productive middle ground be forged? This article…

  13. Forging an Identity over the Life-Course

    ERIC Educational Resources Information Center

    Spiteri, Damian

    2009-01-01

    Using a social constructionist approach, this study explores the self-perceptions of young men who, when at school, were classed as boys with social, emotional and behavioural difficulties (SEBD). The aim is to understand how these perceptions were forged throughout the young men's life-courses resulting in changing self-identities. The study also…

  14. Consolidation and Forging Methods for a Cryomilled Al Alloy

    NASA Astrophysics Data System (ADS)

    Newbery, A. P.; Ahn, B.; Hayes, R. W.; Pao, P. S.; Nutt, S. R.; Lavernia, E. J.

    2008-09-01

    The method used to consolidate a cryogenically ball-milled powder is critical to the retention of superior strength along with acceptable tensile ductility in the bulk product. In this study, gas-atomized Al 5083 powder was cryomilled, hot vacuum degassed, and consolidated by hot isostatic pressing (HIP) or by quasi-isostatic (QI) forging to produce low-porosity billets. The billets were then forged, either at high strain rate (without a die) or quasi-isostatically, and subsequently hot rolled to produce three 6.5-mm-thick plates. Despite extended periods at elevated temperatures and differences between the consolidation/deformation methods, a similar predominantly ultrafine grain microstructure was obtained in all three plates. The plates possessed similar ultimate tensile strengths, about 50 pct greater than standard work-hardened Al 5083. However, in terms of fracture toughness, there were significant differences between the plates. Debonding at prior cryomilled powder particle surfaces was an important fracture mechanism for “HIPped” material, leading to low toughness for crack surfaces in the plane of the plate. This effect was minimized by the implementation of double QI forging, producing plate with good isotropic fracture toughness. The type of particle boundary deformation during forging and the influence of impurities appeared to be more important in determining fracture toughness than the presence of ˜10 vol pct coarser micron-sized grains.

  15. The Valley Forge Encampment: Epic on the Schuylkill.

    ERIC Educational Resources Information Center

    Trussell, John B. B., Jr.

    Valley Forge, outside Philadelphia (Pennsylvania), has long been recognized as the site of a great victory of the human spirit. Eleven thousand men including Blacks and Indians resided there during the winter of 1777-78 and triumphed over cold, starvation, nakedness, disease, and uncertainty. The encampment site was unprepared for the tattered,…

  16. Evaluation of Lubrication Systems for Isothermal Forging of Alpha-Beta and Beta Titanium Alloys.

    DTIC Science & Technology

    1977-11-01

    U R FS , C o n t i n u e d Fliure 19a Closeup t o p view of s t r u c t u r a l compo — nent fore ~ ni s produced by I sot hernia Ifori inq at I t...a 1 Po~~c- ’t i p t j on of iso t hernia l !~-o t ; in ~ Li tb r ican t s Sel e c t e d fo i - Phase I ( ‘ t a sk I I ) i- t I I o t t f o...K20) 24 gm of TiC 457 gin of xylene 78.1 gin of acrylic binder Acheson Delta_ ** water—based silicate glass compound Colloids g laze Company 69 TRW

  17. Parameter Optimization During Forging Process of a Novel High-Speed-Steel Cold Work Roll

    NASA Astrophysics Data System (ADS)

    Guo, Jing; Liu, Ligang; Sun, Yanliang; Li, Qiang; Ren, Xuejun; Yang, Qingxiang

    2016-01-01

    The forging of high-speed-steel (HSS) roll has always been a technical problem in manufacturing industry. In this study, the forging process of a novel HSS cold work roll was simulated by deform-3D on the basis of rigid-viscoplastic finite element model. The effect of heating temperature and forging speed on temperature and stress fields during forging process was simulated too. The results show that during forging process, the temperature of the contact region with anvils increases. The stress of the forging region increases and distributes un-uniformly, while that of the non-forging region is almost zero. With increasing forging time, Z load on anvil increases gradually. With increasing heating temperature or decreasing forging speed, the temperature of the whole billet increases, while the stress and Z load on anvil decrease. In order to ensure the high efficiency and safety of the forging process, the heating temperature and the forging speed are chosen as 1160 °C and 16.667 mm/s, respectively.

  18. Sustained load crack growth design data for Ti-6Al-4V titanium alloy tanks containing hydrazine

    NASA Technical Reports Server (NTRS)

    Lewis, J. C.; Kenny, J. T.

    1976-01-01

    Sustained load crack growth data for Ti-6Al-4V titanium alloy in hydrazine per MIL-P-26536 and refined hydrazine are presented. Fracture mechanics data on crack growth thresholds for heat-treated forgings, aged and unaged welds, and aged and unaged heat-affected zones are reported. Fracture mechanics design curves of crack growth threshold stress intensity versus temperature are generated from 40 to 71 C.

  19. Titanium Nitride Cermets

    DTIC Science & Technology

    1952-07-01

    7696i ’-Brewer, L., et al. Thermodynamic and Physical Properties of Nitrides. Carbides, Sulfides, i1licides, and Phosphides, Chemistry and Metallurgy of...12 Referen eCs 0 . ...................... • • • 14 WADC TR 52-155 iv LIST OF TABLES I Properties of Titanium Nitride Bodies...15 II Properties of Titanium Nitride-Nickel Bodies............16 III Properties of Titanium Nitride Cermets with Nickel,..... 17 Cobalt, and

  20. Development of the Dynamic Globularization Prediction Model for Ti-17 Titanium Alloy Using Finite Element Method

    NASA Astrophysics Data System (ADS)

    Jia, Zhiqiang; Zeng, Weidong; Xu, Jianwei; Zhou, Jianhua; Wang, Xiaoying

    2015-04-01

    In this work, a finite element method (FEM) model for predicting dynamic globularization of Ti-17 titanium alloy is established. For obtaining the microstructure evolution during dynamic globularization under varying processing parameters, isothermal hot compression tests and quantitative metallographic analysis were conducted on Ti-17 titanium alloy with initial lamellar microstructure. The prediction model, which quantitatively described the non-linear relationship between the dynamic globularization fraction and the deformation strain, temperature, and strain rate, was developed on the basis of the Avrami equation. Then the developed model was incorporated into DEFORM software as a user subroutine. Finally, the large-sized step-shaped workpiece was isothermally forged and corresponding FEM simulation was conducted to verify the reliability and accuracy of the integrated FEM model. The reasonable coincidence of the predicted results with experimental ones indicated that the established FEM model provides an easy and a practical method to predict dynamic globularization for Ti-17 titanium alloy with complex shape.

  1. First Results of Energy Saving at Process Redesign of Die Forging Al-Alloys

    SciTech Connect

    Pepelnjak, Tomaz; Kuzman, Karl; Kokol, Anton

    2011-05-04

    The contribution deals with eco-friendly solutions for shortened production chains of forging light alloys. During the die forging operations a remarkable amount of material goes into the flash and later on into chips during finish machining. These low value side products are rich with embedded energy therefore recycling or reprocessing could be very energy saving procedure.In cooperation with a die forging company a shortened reprocessing cycle has been studied starting from re-melting the forging flash and without additional heating to cast preforms for subsequent die forging. As such preforms have not as good formability characteristics as those done from extruded billets the isothermal forging process has been adopted. First results showed that without cracks and other defects the formability is sufficient for a broad spectrum of forgings.To improve the formability a homogenization process of cast preforms has been implemented. As the process started immediately after casting, amount of additional energy for heating was minimized. To reduce voids forging process was redesigned in a way to assure greater hydrostatic pressures in parts during forging. First results were promising therefore research is going towards improving processes without adding significantly more energy as it is needed for casting with homogenization and die forging.

  2. West Flank Coso, CA FORGE ArcGIS data 2

    DOE Data Explorer

    Doug Blankenship

    2016-03-01

    archive of ArcGIS data from the West Flank FORGE site located in Coso, California. Archive contains: 8 shapefiles polygon of the 3D geologic model polylines of the traces 3D modeled faults polylines of the fault traces from Duffield and Bacon, 1980 polygon of the West Flank FORGE site polylines of the traces of the geologic cross-sections (cross-sections in a separate archive in the GDR) polylines of the traces of the seismic reflection profiles through and adjacent to the West Flank site (seismic reflection profiles in a separate archive in the GDR) points of the well collars in and around the West Flank site polylines of the surface expression of the West Flank well paths

  3. Crack toughness evaluation of hot pressed and forged beryllium.

    NASA Technical Reports Server (NTRS)

    Jones, M. H.; Bubsey, R. T.; Brown, W. F., Jr.

    1973-01-01

    Fracture toughness tests at room temperature were made on three-point loaded beryllium bend specimens cut from hot pressed block and a forged disk. These specimens had plane proportions conforming to ASTM E 399 and covered a thickness range of from 1/32 to 1/2 in. Two sets of bend specimens were tested, one having fatigue cracks and the other 0.5 mil radius notches. One objective of the investigation was the development of techniques to produce fatigue cracks in accordance with the procedures specified in ASTM E 399. This objective was achieved for the hot pressed material. In plane cracks were not consistently produced in the specimens cut from forged stock.

  4. Process modelings and simulations of heavy castings and forgings

    NASA Astrophysics Data System (ADS)

    Li, Dianzhong; Sun, Mingyue; Wang, Pei; Kang, Xiuhong; Fu, Paixian; Li, Yiyi

    2013-05-01

    The Materials Process Modeling Division, IMR, CAS has been promoting for more than 10 years research activities on modeling and experimental studies on heavy castings and forgings. In this report, we highlight some selected achievements and impacts in this area: To satisfy domestic strategic requirements, such as nuclear and hydraulic power, marine projects and high speed rail, we have developed a number of casting and forging technologies, which combine advanced computing simulations, X-ray real time observation techniques and industrial-scaled trial experiments. These technologies have been successfully applied in various industrial areas and yielded a series of scientific and technological breakthroughs and innovation. Important examples of this strategic research include the hot-processing technologies of the Three Gorge water turbine runner, marine crankshaft manufacturers, backup rolls for hot rolling mills and the production of hundreds-ton steel ingot.

  5. Performance Assessment Method for a Forged Fingerprint Detection Algorithm

    NASA Astrophysics Data System (ADS)

    Shin, Yong Nyuo; Jun, In-Kyung; Kim, Hyun; Shin, Woochang

    The threat of invasion of privacy and of the illegal appropriation of information both increase with the expansion of the biometrics service environment to open systems. However, while certificates or smart cards can easily be cancelled and reissued if found to be missing, there is no way to recover the unique biometric information of an individual following a security breach. With the recognition that this threat factor may disrupt the large-scale civil service operations approaching implementation, such as electronic ID cards and e-Government systems, many agencies and vendors around the world continue to develop forged fingerprint detection technology, but no objective performance assessment method has, to date, been reported. Therefore, in this paper, we propose a methodology designed to evaluate the objective performance of the forged fingerprint detection technology that is currently attracting a great deal of attention.

  6. Sealing glasses for titanium and titanium alloys

    DOEpatents

    Brow, Richard K.; McCollister, Howard L.; Phifer, Carol C.; Day, Delbert E.

    1997-01-01

    Barium lanthanoborate sealing-glass compositions are provided comprising various combinations (in terms of mole-%) of boron oxide (B.sub.2 O.sub.3), barium oxide (BaO), lanthanum oxide (La.sub.2 O.sub.3), and at least one other oxide selected from the group consisting of aluminum oxide (Al.sub.2 O.sub.3), calcium oxide (CaO), lithium oxide (Li.sub.2 O), sodium oxide (Na.sub.2 O), silicon dioxide (SiO.sub.2), or titanium dioxide (TiO.sub.2). These sealing-glass compositions are useful for forming hermetic glass-to-metal seals with titanium and titanium alloys having an improved aqueous durability and favorable sealing characteristics. Examples of the sealing-glass compositions are provided having coefficients of thermal expansion about that of titanium or titanium alloys, and with sealing temperatures less than about 900.degree. C., and generally about 700.degree.-800.degree. C. The barium lanthanoborate sealing-glass compositions are useful for components and devices requiring prolonged exposure to moisture or water, and for implanted biomedical devices (e.g. batteries, pacemakers, defibrillators, pumps).

  7. Sealing glasses for titanium and titanium alloys

    DOEpatents

    Brow, R.K.; McCollister, H.L.; Phifer, C.C.; Day, D.E.

    1997-07-15

    Barium lanthanoborate sealing-glass compositions are provided comprising various combinations (in terms of mole-%) of boron oxide (B{sub 2}O{sub 3}), barium oxide (BaO), lanthanum oxide (La{sub 2}O{sub 3}), and at least one other oxide selected from the group consisting of aluminum oxide (Al{sub 2}O{sub 3}), calcium oxide (CaO), lithium oxide (Li{sub 2}O), sodium oxide (Na{sub 2}O), silicon dioxide (SiO{sub 2}), or titanium dioxide (TiO{sub 2}). These sealing-glass compositions are useful for forming hermetic glass-to-metal seals with titanium and titanium alloys having an improved aqueous durability and favorable sealing characteristics. Examples of the sealing-glass compositions are provided having coefficients of thermal expansion about that of titanium or titanium alloys, and with sealing temperatures less than about 900 C, and generally about 700--800 C. The barium lanthanoborate sealing-glass compositions are useful for components and devices requiring prolonged exposure to moisture or water, and for implanted biomedical devices (e.g. batteries, pacemakers, defibrillators, pumps). 1 fig.

  8. Optimization of custom cementless stem using finite element analysis and elastic modulus distribution for reducing stress-shielding effect.

    PubMed

    Saravana Kumar, Gurunathan; George, Subin Philip

    2017-02-01

    This work proposes a methodology involving stiffness optimization for subject-specific cementless hip implant design based on finite element analysis for reducing stress-shielding effect. To assess the change in the stress-strain state of the femur and the resulting stress-shielding effect due to insertion of the implant, a finite element analysis of the resected femur with implant assembly is carried out for a clinically relevant loading condition. Selecting the von Mises stress as the criterion for discriminating regions for elastic modulus difference, a stiffness minimization method was employed by varying the elastic modulus distribution in custom implant stem. The stiffness minimization problem is formulated as material distribution problem without explicitly penalizing partial volume elements. This formulation enables designs that could be fabricated using additive manufacturing to make porous implant with varying levels of porosity. Stress-shielding effect, measured as difference between the von Mises stress in the intact and implanted femur, decreased as the elastic modulus distribution is optimized.

  9. Prospective five-year subsidence analysis of a cementless fully hydroxyapatite-coated femoral hip arthroplasty component.

    PubMed

    Clauss, Martin; Van Der Straeten, Catherine; Goossens, Marc

    2014-01-01

    Early subsidence >1.5 mm is considered to be a predictive factor for later aseptic loosening of the femoral component following total hip arthroplasty (THA). The aim of this study was to assess five-year subsidence rates of the cementless hydroxyapatite-coated twinSys stem (Mathys Ltd., Bettlach, Switzerland).This prospective single-surgeon series examined consecutive patients receiving a twinSys stem at Maria Middelares Hospital, Belgium. Patients aged >85 years or unable to come to follow-up were excluded. Subsidence was assessed using Ein Bild Roentgen Analyse--Femoral Component Analysis (EBRA-FCA). Additional clinical and radiographic assessments were performed. Follow-ups were prospectively scheduled at two, five, 12, 24, and 60 months.In total, 218 THA (211 patients) were included. At five years, mean subsidence was 0.66 mm (95% CI: 0.43-0.90). Of the 211 patients, 95.2% had an excellent or good Harris Hip Score. There were few radiological changes. Kaplan-Meier analysis indicated five-year stem survival to be 98.4% (95% CI: 97.6-100%).Subsidence levels of the twinSys femoral stem throughout the five years of follow-up were substantially lower than the 1.5 mm level predictive of aseptic loosening. This was reflected in the high five-year survival rate.

  10. Highly Cross-linked Polyethylene Liner Dissociation from a Cement-less Modular Acetabular Shell: Two Case Reports

    PubMed Central

    Kawano, Shunsuke; Sonohata, Motoki; Kitajima, Masaru; Mawatari, Masaaki

    2016-01-01

    Liner dissociation of polyethylene from a cementless acetabular socket following total hip arthroplasty (THA) is a rare complication. Cross-linked polyethylene liner dissociation from AMS-HA shell (KYOCERA Med, Osaka, Japan) occurred in 2 out of the 4153 (0.04%) cases approximately 10 years after undergoing surgery at our institute. First case was an 80-year-old female who underwent right THA along with subtrochanteric femoral shortening osteotomy due to complete dislocation hip, and second case was a 72-year-old male, who underwent right THA due to coxarthrosis. A 26 mm femoral head and CPE liner were used in both cases and the inclination degree of the acetabular socket was within 50°.There was no implant loosening in both cases. There was partial damage in the elevated rim on the alternative side and scratches on the back side in the both extracted CPE liner. It was surmised that liner dissociation was caused due to a problem in the liner fixing format of the push in type of the present model. PMID:28217197

  11. Internal Shear Forging Processes for Missile Primary Structures.

    DTIC Science & Technology

    1981-07-20

    Different Thermal-Mechanical Cycles. .. .. .. 91 9 Effect of Final Aging Treatment on Tensile Properties of 2014 Aluminum Alloy...naturally aged to the T4 condition. .. ... ......... ......... ... 51 39 Initial tooling design for internal shear forging. .. .. ... 58 40...treatable age -hardening alloy and contains Al with Cu, Mg, and Si as the main alloying elements. Addition of Si enhances the response to artificial aging (T6

  12. Material morphological characteristics in laser ablation of alpha case from titanium alloy

    NASA Astrophysics Data System (ADS)

    Yue, Liyang; Wang, Zengbo; Li, Lin

    2012-08-01

    Alpha case (an oxygen enriched alloy layer) is commonly formed in forged titanium alloys during the manufacturing process and it reduces the service life of the materials. This layer is normally removed mechanically or chemically. This paper reports the feasibility and characteristics of using a short pulsed laser to remove oxygen-enriched alpha case layer from a titanium alloy (Ti6Al4V) substrate. The material removal rate, i.e., ablation rate, and ablation threshold of the alpha case titanium were experimentally determined, and compared with those for the removal of bulk Ti6Al4V. Surface morphologies of laser processed alpha case titanium layer, especially that of cracks at different ablated depths, were carefully examined, and also compared with those for Ti6Al4V. It has been shown that in the alpha case layer, laser ablation has always resulted in crack formation while for laser ablation of alpha case free Ti6Al4V layers, cracking was not present. In addition, the surface is rougher within the alpha case layer and becomes smoother (Ra - 110 nm) once the substrate Ti-alloy is reached. The work has demonstrated that laser is a feasible processing tool for removing alpha case titanium, and could also be used for the rapid detection of the presence of alpha case titanium on Ti6Al4V surfaces in aerospace applications.

  13. Sprayable titanium composition

    DOEpatents

    Tracy, Chester E.; Kern, Werner; Vibronek, Robert D.

    1980-01-01

    The addition of 2-ethyl-1-hexanol to an organometallic titanium compound dissolved in a diluent and optionally containing a lower aliphatic alcohol spreading modifier, produces a solution that can be sprayed onto a substrate and cured to form an antireflection titanium oxide coating having a refractive index of from about 2.0 to 2.2.

  14. Fracture behavior of warm forged and CVD tungsten

    SciTech Connect

    Lassila, D.H.; Connor, A.

    1991-02-14

    The fracture behavior of warm forged and chemical vapor deposition (CVD) tungsten was studied. Three-point bend tests were used to determine ductile-brittle transition temperatures (DBTT) of the materials using a strain based criterion for the DBTT which was arrived at by analysis of computer code modelling results of the three-point bend test. The DBTT's of the warm forged materials were found to be considerably lower than those of the CVD materials. Scanning electron microscopy (SEM), scanning Auger electron spectroscopy (SAES) and X-ray photoelectron spectroscopy (XPS) were performed to characterize the fracture morphologies and fracture surface compositions of the materials. All fracture surfaces were found to be comprised entirely of tungsten with significant and varying amounts of oxygen and carbon segregation. A large portion of the fracture surfaces of the warm forged materials is intergranular, although this is not always directly evident from SEM observations. The fracture surfaces of the CVD materials were clearly 100% intergranular. Results of the study suggest that the fracture paths of the different materials were related to the DBTTs. 22 refs., 8 figs., 2 tabs.

  15. Influence of Processing Parameters on Grain Size Evolution of a Forged Superalloy

    NASA Astrophysics Data System (ADS)

    Reyes, L. A.; Páramo, P.; Salas Zamarripa, A.; de la Garza, M.; Guerrero-Mata, M. P.

    2016-01-01

    The microstructure evolution of nickel-based superalloys has a great influence on the mechanical behavior during service conditions. Microstructure modification and the effect of process variables such as forging temperature, die-speed, and tool heating were evaluated after hot die forging of a heat-resistant nickel-based alloy. Forging sequences in a temperature range from 1253 to 1323 K were considered through experimental trials. An Avrami model was applied using finite element data to evaluate the average grain size and recrystallization at different evolution zones. It was observed that sequential forging at final temperatures below 1273 K provided greater grain refinement through time-dependent recrystallization phenomena. This investigation was aim to explore the influence of forging parameters on grain size evolution in order to design a fully homogenous and refined microstructure after hot die forging.

  16. High-energy rate forgings of wedges. Characterization of processing conditions

    SciTech Connect

    Reynolds, Thomas Bither; Everhart, Wesley; Switzner, Nathan T; Balch, Dorian K.; San Marchi, Christopher W.

    2014-05-01

    The wedge geometry is a simple geometry for establishing a relatively constant gradient of strain in a forged part. The geometry is used to establish gradients in microstructure and strength as a function of strain, forging temperature, and quenching time after forging. This geometry has previously been used to benchmark predictions of strength and recrystallization using Sandias materials model for type 304L austenitic stainless steel. In this report, the processing conditions, in particular the times to forge and quench the forged parts, are summarized based on information recorded during forging on June 18, 2013 of the so-called wedge geometry from type 316L and 21Cr-6Ni-9Mn austenitic stainless steels.

  17. Titanium and titanium alloys as dental materials.

    PubMed

    Lautenschlager, E P; Monaghan, P

    1993-06-01

    Because of light weight, high strength to weight ratio, low modulus of elasticity, and excellent corrosion resistance, titanium and some of its alloys have been important materials for the aerospace industry since the 1950s. Now, with the additional advantages of excellent biocompatibility, good local spot weldability, and easy shaping and finishing by a number of mechanical and electrochemical processes, these materials are finding uses in dental applications, such as implants and restorative castings. Although more research is still needed in areas such as development of optimal casting investments, porcelain veneering systems, device designs, and controlled biological responses, the present and future uses of titanium appear bright for dentistry.

  18. Two-stage revision surgery with preformed spacers and cementless implants for septic hip arthritis: a prospective, non-randomized cohort study

    PubMed Central

    2011-01-01

    Background Outcome data on two-stage revision surgery for deep infection after septic hip arthritis are limited and inconsistent. This study presents the medium-term results of a new, standardized two-stage arthroplasty with preformed hip spacers and cementless implants in a consecutive series of adult patients with septic arthritis of the hip treated according to a same protocol. Methods Nineteen patients (20 hips) were enrolled in this prospective, non-randomized cohort study between 2000 and 2008. The first stage comprised femoral head resection, debridement, and insertion of a preformed, commercially available, antibiotic-loaded cement hip spacer. After eradication of infection, a cementless total hip arthroplasty was implanted in the second stage. Patients were assessed for infection recurrence, pain (visual analog scale [VAS]) and hip joint function (Harris Hip score). Results The mean time between first diagnosis of infection and revision surgery was 5.8 ± 9.0 months; the average duration of follow up was 56.6 (range, 24 - 104) months; all 20 hips were successfully converted to prosthesis an average 22 ± 5.1 weeks after spacer implantation. Reinfection after total hip joint replacement occurred in 1 patient. The mean VAS pain score improved from 48 (range, 35 - 84) pre-operatively to 18 (range, 0 - 38) prior to spacer removal and to 8 (range, 0 - 15) at the last follow-up assessment after prosthesis implantation. The average Harris Hip score improved from 27.5 before surgery to 61.8 between the two stages to 92.3 at the final follow-up assessment. Conclusions Satisfactory outcomes can be obtained with two-stage revision hip arthroplasty using preformed spacers and cementless implants for prosthetic hip joint infections of various etiologies. PMID:21575241

  19. Mechanical-Property Data Ti-10V-2Fe-3Al Alloy. Isothermally Forged

    DTIC Science & Technology

    1982-06-01

    mm) RCS, reheated to 1700 F (1200 K) and forged to a 5-inch (127 mm) RCS, reheated to 1500 F ( 1089 K) and forged to a 4-inch (102 mm) octagon. A final...pass at RMI was performed in a rotary forging machine at 1500 F ( 1089 K) transfoiming the octagon 4 "to a 3-1/4-inch (8.26 mm) diameter round bar. At

  20. Prospective randomised clinical trial assessing subsidence and rotation, using radiostereometric analysis, of two modular cementless femoral stems (Global K2 and Apex)

    PubMed Central

    Edmondson, Mark; Ebert, Jay; Nivbrant, Oscar; Wood, David

    2014-01-01

    Aims To accurately assess subsidence, rotation and clinical scores in two cementless femoral stems. Methods 260 patients received either K2 or Apex femoral stems and were studied over 2y, with RSA and clinical scores. Results Mean Oxford Hip score for both stems was excellent (45.78 and 46.76). Very little subsidence or rotation were noted on RSA in either stem. There were no statistically significant differences in clinical scores, or radiological motion between stems. Revision rate was 0.8% over the study period. Conclusion Excellent clinical and RSA scores over the 2y study period predict good long term outcomes for these stems. PMID:25104894

  1. Residual Stresses in 21-6-9 Stainless Steel Warm Forgings

    SciTech Connect

    Everhart, Wesley A.; Lee, Jordan D.; Broecker, Daniel J.; Bartow, John P.; McQueen, Jamie M.; Switzner, Nathan T.; Neidt, Tod M.; Sisneros, Thomas A.; Brown, Donald W.

    2012-11-14

    Forging residual stresses are detrimental to the production and performance of derived machined parts due to machining distortions, corrosion drivers and fatigue crack drivers. Residual strains in a 21-6-9 stainless steel warm High Energy Rate Forging (HERF) were measured via neutron diffraction. The finite element analysis (FEA) method was used to predict the residual stresses that occur during forging and water quenching. The experimentally measured residual strains were used to calibrate simulations of the three-dimensional residual stress state of the forging. ABAQUS simulation tools predicted residual strains that tend to match with experimental results when varying yield strength is considered.

  2. Opacity and Mass Emission Relationship in Forging Areas of Large Caliber Metal Parts Facilities,

    DTIC Science & Technology

    1981-11-01

    was tested to he 0.0058 gr/dscf. The lubricating oil used at Flinchbaugh is designated as Hot Forging Agent 201 (HF 201), manufactured by E. F. Houghton...at the New Bedford forgi, shop are designated as MacForge 599 and MacForge-, 958. MacForge 958 is water, based, containing 1? percent oil and 24...determine mass emissions from optical density at another plant, the particulate characteristics and the ptrocess imu t be very siwilar to the plant

  3. Forge Welding of Magnesium Alloy to Aluminum Alloy Using a Cu, Ni, or Ti Interlayer

    NASA Astrophysics Data System (ADS)

    Yamagishi, Hideki; Sumioka, Junji; Kakiuchi, Shigeki; Tomida, Shogo; Takeda, Kouichi; Shimazaki, Kouichi

    2015-08-01

    The forge-welding process was examined to develop a high-strength bonding application of magnesium (Mg) alloy to aluminum (Al) alloy under high-productivity conditions. The effect of the insert material on the tensile strength of the joints, under various preheat temperatures and pressures, was investigated by analyzing the reaction layers of the bonded interface. The tensile strengths resulting from direct bonding, using pure copper (Cu), pure nickel (Ni), and pure titanium (Ti) inserts were 56, 100, 119, and 151 MPa, respectively. The maximum joint strength reached 93 pct with respect to the Mg cast billet. During high-pressure bonding, a microscopic plastic flow occurred that contributed to an anchor effect and the generation of a newly formed surface at the interface, particularly prominent with the Ti insert in the form of an oxide layer. The bonded interfaces of the maximum-strength inserts were investigated using scanning electron microscopy-energy-dispersive spectroscopy and electron probe microanalysis. The diffusion reaction layer at the bonded interface consisted of brittle Al-Mg intermetallics having a thickness of approximately 30 μm. In contrast, for the three inserts, the thicknesses of the diffusion reaction layer were infinitely thin. For the pure Ti insert, exhibiting the maximum tensile strength value among the inserts tested, focused ion beam-transmission electron microscopy-EDS analysis revealed a 60-nm-thick Al-Ti reaction layer, which had formed at the bonded interface on the Mg alloy side. Thus, a high-strength Al-Mg bonding method in air was demonstrated, suitable for mass production.

  4. Electroplating on titanium alloy

    NASA Technical Reports Server (NTRS)

    Lowery, J. R.

    1971-01-01

    Activation process forms adherent electrodeposits of copper, nickel, and chromium on titanium alloy. Good adhesion of electroplated deposits is obtained by using acetic-hydrofluoric acid anodic activation process.

  5. Performance of hot stacked-sinter forged Bi2223 ceramics

    NASA Astrophysics Data System (ADS)

    Noudem, J. G.; Guilmeau, E.; Chateigner, D.; Ouladdiaf, B.; Bourgault, D.

    2004-08-01

    Dense Bi2223 superconductors have been successfully formed by hot stacking-forging process (HSF). Neutron diffraction measurements were used to investigate the bulk textures of HSF-Bi2223 samples. Angular dependence of transport critical current density, Jc values were measured at various temperatures and different applied magnetic fields. Several textured pieces were hot-stacked. This procedure leads to an increase of both the sample thickness and the nominal engineering critical current ( Ic), favourable hints for use of textured-Bi2223 in power generation supplies.

  6. West Flank Coso, CA FORGE 3D geologic model

    SciTech Connect

    Doug Blankenship

    2016-03-01

    This is an x,y,z file of the West Flank FORGE 3D geologic model. Model created in Earthvision by Dynamic Graphic Inc. The model was constructed with a grid spacing of 100 m. Geologic surfaces were extrapolated from the input data using a minimum tension gridding algorithm. The data file is tabular data in a text file, with lithology data associated with X,Y,Z grid points. All the relevant information is in the file header (the spatial reference, the projection etc.) In addition all the fields in the data file are identified in the header.

  7. Snake River Plain FORGE Well Data for USGS-142

    SciTech Connect

    Robert Podgorney

    2015-11-23

    Well data for the USGS-142 well located in eastern Snake River Plain, Idaho. This data collection includes lithology reports, borehole logs, and photos of rhyolite core samples. This collection of data has been assembled as part of the site characterization data used to develop the conceptual geologic model for the Snake River Plain site in Idaho, as part of phase 1 of the Frontier Observatory for Research in Geothermal Energy (FORGE) initiative. They were assembled by the Snake River Geothermal Consortium (SRGC), a team of collaborators that includes members from national laboratories, universities, industry, and federal agencies, lead by the Idaho National Laboratory (INL).

  8. Ibandronate and cementless total hip arthroplasty: densitometric measurement of periprosthetic bone mass and new therapeutic approach to the prevention of aseptic loosening

    PubMed Central

    Muratore, Maurizio; Quarta, Eugenio; Quarta, Laura; Calcagnile, Fabio; Grimaldi, Antonella; Orgiani, M. Antonio; Marsilio, Antonio; Rollo, Giuseppe

    2012-01-01

    Summary Studies of the mechanisms of periprosthetic bone loss have led to the development of pharmacologic strategies intended to enhance bone mass recovery after surgery and consequently prevent aseptic loosening and prolong the implant survival. Bisphosphonates, potent anti-resorptive drugs widely used in the treatment of osteoporosis and other disorders of bone metabolism, were shown to be particularly effective in reducing periprosthetic bone resorption in the first year after hip and knee arthroplasty, both cemented and cementless. Based on these results, we investigated the inhibitory effects of ibandronate on periprosthetic bone loss in a 2-year study of postmenopausal women that underwent cementless total hip arthroplasty. In the first 6 months both groups (A, treated with ibandronate 3 mg i.v. within five days after surgery and then with oral ibandronate 150 mg/month, plus calcium and vitamin D supplementation; and B, treated with calcium and vitamin D supplementation only) experienced bone loss, though to a lesser extent in group A. After 12 months, group A showed a remarkable BMD recovery, that was statistically significant versus baseline values (about +1, 74% of global BMD) and most evident in region R1 (+3, 81%) and R2 (+4, 12%); in group B, on the contrary, BMD values were unchanged compared with those at 6 months post-surgery. Quality of life scores also showed a greater improvement in group A, both at 6 and 12 months after surgery, likely because of the pain-reducing effects of ibandronate treatment. PMID:22783337

  9. Research of annealing mode for high accuracy stamped parts production from titanium alloy 83Ti-5Al-5Cr-5Mo after tooling

    NASA Astrophysics Data System (ADS)

    Balaykin, A. V.; Nosova, E. A.; Galkina, N. V.

    2016-11-01

    The aim of the work is to solve question of accuracy increase in tolled and annealed parts made from forged rod of titanium alloy. Plate pieces were cut from cross-section, annealed at 800°C during 1, 2, 3, 4 and 5 hours. The criterion combining minimum bending radius and spring back angle was found. This criterion shows the maximum values after tooling and annealing for 3 hours.

  10. Microstructure Modeling of a Ni-Fe-Based Superalloy During the Rotary Forging Process

    NASA Astrophysics Data System (ADS)

    Loyda, A.; Hernández-Muñoz, G. M.; Reyes, L. A.; Zambrano-Robledo, P.

    2016-06-01

    The microstructure evolution of Ni-Fe superalloys has a great influence on the mechanical behavior during service conditions. The rotary forging process offers an alternative to conventional bulk forming processes where the parts can be rotary forged with a fraction of the force commonly needed by conventional forging techniques. In this investigation, a numerical modeling of microstructure evolution for design and optimization of the hot forging operations has been used to manufacture a heat-resistant nickel-based superalloy. An Avrami model was implemented into finite element commercial platform DEFORM 3D to evaluate the average grain size and recrystallization during the rotary forging process. The simulations were carried out considering three initial temperatures, 980, 1000, and 1050 °C, to obtain the microstructure behavior after rotary forging. The final average grain size of one case was validated by comparing with results of previous experimental work of disk forging operation. This investigation was aimed to explore the influence of the rotary forging process on microstructure evolution in order to obtain a homogenous and refined grain size in the final component.

  11. 76 FR 66996 - Agency Information Collection Activities; Submission for OMB Review; Comment Request; Forging...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-28

    ...; Forging Machines ACTION: Notice. SUMMARY: The Department of Labor (DOL) is submitting the Occupational... Machines,'' to the Office of Management and Budget (OMB) for review and approval for continued use in... employers to conduct and to document periodic inspections of forging machines, guards, and...

  12. [Research on the inner wall condition monitoring method of ring forgings based on infrared spectra].

    PubMed

    Fu, Xian-bin; Liu, Bin; Wei, Bin; Zhang, Yu-cun; Liu, Zhao-lun

    2015-01-01

    In order to grasp the inner wall condition of ring forgings, an inner wall condition monitoring method based on infrared spectra for ring forgings is proposed in the present paper. Firstly, using infrared spectroscopy the forgings temperature measurement system was built based on the three-level FP-cavity LCTF. The two single radiation spectra from the forgings' surface were got using the three-level FP-cavity LCTF. And the temperature measuring of the surface forgings was achieved according to the infrared double-color temperature measuring principle. The measuring accuracy can be greatly improved by this temperature measurement method. Secondly, on the basis of the Laplace heat conduction differential equation the inner wall condition monitoring model was established by the method of separating variables. The inner wall condition monitoring of ring forgings was realized via combining the temperature data and the forgings own parameter information. Finally, this method is feasible according to the simulation experiment. The inner wall condition monitoring method can provide the theoretical basis for the normal operating of the ring forgings.

  13. Forging; Heat Treating and Testing; Technically Oriented Industrial Materials and Process 1: 5898.05.

    ERIC Educational Resources Information Center

    Dade County Public Schools, Miami, FL.

    The course provides students with advanced and exploratory experience in the area of plastic deformation of metals and in the changing of the physical characteristics of metals by the controlled application and timed removal of heat. Course content includes goals, specific objectives, safety in forge work, forging tools and equipment, industrial…

  14. 75 FR 67110 - Forged Stainless Steel Flanges From India and Taiwan

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-01

    ... COMMISSION Forged Stainless Steel Flanges From India and Taiwan AGENCY: United States International Trade... stainless steel flanges from India and Taiwan. SUMMARY: The Commission hereby gives notice that it has... determine whether revocation of the antidumping duty orders on forged stainless steel flanges from India...

  15. 75 FR 70689 - Kaiser Aluminum Fabricated Products, LLC; Kaiser Aluminum-Greenwood Forge Division; Currently...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-18

    ... Employment and Training Administration Kaiser Aluminum Fabricated Products, LLC; Kaiser Aluminum- Greenwood... Aluminum Fabricated Products, LLC, Kaiser Aluminum-Greenwood Forge Division, including on- site leased... are engaged in the production of aluminum alloy forgings. Information shows that on July 28,...

  16. Vibration control in forge hammers. [by shock wave damping in foundation platform

    NASA Technical Reports Server (NTRS)

    Moise, F.; Lazarescu, C.

    1974-01-01

    Special measures are discussed for calculating, designing and executing a forge hammer foundation, so that the vibrations that occur during its working will not be transmitted to neighboring machinery, workrooms and offices. These vibrations are harmful to the workers near the forge hammer.

  17. A New Method for Controlling Billet Temperature During Isothermal Die Forging of a Complex Superalloy Casing

    NASA Astrophysics Data System (ADS)

    Lin, Y. C.; Wu, Xian-Yang

    2015-09-01

    Isothermal die forging is one of near net-shape metal-forming technologies. Strict control of billet temperature during isothermal die forging is a guarantee for the excellent properties of final product. In this study, a new method is proposed to accurately control the billet temperature of complex superalloy casing, based on the finite element simulation and response surface methodology (RSM). The proposed method is accomplished by the following two steps. Firstly, the thermal compensation process is designed and optimized to overcome the inevitable heat loss of dies during hot forging. i.e., the layout and opening time of heaters assembled on die sleeves are optimized. Then, the effects of forging speed (the pressing velocity of hydraulic machine) and its changing time on the maximum billet temperature are discussed. Furthermore, the optimized forging speed and its changing time are obtained by RSM. Comparisons between the optimized and conventional die forging processes indicate that the proposed method can effectively control the billet temperature within the optimal forming temperature range. So, the optimized die forging processes can guarantee the high volume fraction of dynamic recrystallization, and restrict the rapid growth of grains in the forged superalloy casing.

  18. Low Temperature Superplasticity of Ti-6Al-4V Processed by Warm Multidirectional Forging (Preprint)

    DTIC Science & Technology

    2012-07-01

    temperature superplasticity, multidirectional forging , ultrafine grain structure , microstructure evolution 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF...mail.ru, dLee.Semiatin@wpafb.af.mil Keywords: Low-temperature superplasticity, Multidirectional forging , Ultrafine grain structure , Microstructure... Metals Branch Structural Materials Division G.A. Salishchev, E.A. Kudrjavtsev, and S.V. Zherebtsov Belgorod State University July

  19. Titanium by design: TRIP titanium alloy

    NASA Astrophysics Data System (ADS)

    Tran, Jamie

    Motivated by the prospect of lower cost Ti production processes, new directions in Ti alloy design were explored for naval and automotive applications. Building on the experience of the Steel Research Group at Northwestern University, an analogous design process was taken with titanium. As a new project, essential kinetic databases and models were developed for the design process and used to create a prototype design. Diffusion kinetic models were developed to predict the change in phase compositions and microstructure during heat treatment. Combining a mobility database created in this research with a licensed thermodynamic database, ThermoCalc and DICTRA software was used to model kinetic compositional changes in titanium alloys. Experimental diffusion couples were created and compared to DICTRA simulations to refine mobility parameters in the titanium mobility database. The software and database were able to predict homogenization times and the beta→alpha plate thickening kinetics during cooling in the near-alpha Ti5111 alloy. The results of these models were compared to LEAP microanalysis and found to be in reasonable agreement. Powder metallurgy was explored using SPS at GM R&D to reduce the cost of titanium alloys. Fully dense Ti5111 alloys were produced and achieved similar microstructures to wrought Ti5111. High levels of oxygen in these alloys increased the strength while reducing the ductility. Preliminary Ti5111+Y alloys were created, where yttrium additions successfully gettered excess oxygen to create oxides. However, undesirable large oxides formed, indicating more research is needed into the homogeneous distribution of the yttrium powder to create finer oxides. Principles established in steels were used to optimize the beta phase transformation stability for martensite transformation toughening in titanium alloys. The Olson-Cohen kinetic model is calibrated to shear strains in titanium. A frictional work database is established for common alloying

  20. Fracture Mechanical Measurements with Commercial Stainless Steels at 4 K and with Cp-Titanium at 173 K

    NASA Astrophysics Data System (ADS)

    Nyilas, A.; Mitterbacher, H.

    2010-04-01

    Using the JETT (J-Evaluation on Tensile Test) technique, measurements have been performed with commercial stainless steels in forged and cast condition for the reason of an assessment for low temperature service down to 4 K. These steels frequently used for industrial applications are designated by German Werkstoff (WNr) 1.4308 and 1.4408 cast stainless steels and a forged material with the number 1.4307. The fracture toughness tests at 4 K with forged material 1.4307 comprised apart from the base metal also the weld zone and additionally the 5% and 8% pre-strained conditions of the base metal. Fracture toughness reduced slightly for cold worked condition gradually as well as for the weld joint. The Reliability of the JETT measurements has been also checked using the ASTM E 1820—99a standard. In addition, to these measurements, commercial pure ASTM grade 2 titanium (WNr 3.7035) has been also examined using the same JETT method for the reason of industrial application and the requirement of minimum fracture toughness of 100 MPa√m was fulfilled at 173 K. Furthermore, test results performed at 7 K of pure titanium plate material (ASTM grade 1) with respect to fracture mechanical JETT method are presented.

  1. Carbon/PEEK composite materials as an alternative for stainless steel/titanium hip prosthesis: a finite element study.

    PubMed

    Rezaei, Farshid; Hassani, Kamran; Solhjoei, Nosratollah; Karimi, Alireza

    2015-12-01

    Total hip replacement (THR) has been ranked within the most typical surgical processes in the world. The durability of the prosthesis and loosening of prosthesis are the main concerns that mostly reported after THR surgeries. In THR, the femoral prosthesis can be fixed by either cement or cementless methods in the patient's bones. In both procedures, the stability of the prosthesis in the hosted bone has a key asset in its long-term durability and performance. This study aimed to execute a comparative finite element simulation to assess the load transfer between the prosthesis, which is made of carbon/PEEK composite and stainless steel/titanium, and the femur bone. The mechanical behavior of the cortical bone was assumed as a linear transverse isotropic while the spongy bone was modeled like a linear isotropic material. The implants were made of stainless steel (316L) and titanium alloy as they are common materials for implants. The results showed that the carbon/PEEK composites provide a flatter load transfer from the upper body to the leg compared to the stainless steel/titanium prosthesis. Furthermore, the results showed that the von Mises stress, principal stress, and the strain in the carbon/PEEK composites prosthesis were significantly lower than that made of the stainless steel/titanium. The results also imply that the carbon/PEEK composites can be applied to introduce a new optimum design for femoral prosthesis with adjustable stiffness, which can decrease the stress shielding and interface stress. These findings will help clinicians and biomedical experts to increase their knowledge about the hip replacement.

  2. Research into Oil-based Colloidal-Graphite Lubricants for Forging of Al-based Alloys

    SciTech Connect

    Petrov, A.; Petrov, P.; Petrov, M.

    2011-05-04

    The presented paper describes the topical problem in metal forging production. It deals with the choice of an optimal lubricant for forging of Al-based alloys. Within the scope of the paper, the properties of several oil-based colloidal-graphite lubricants were investigated. The physicochemical and technological properties of these lubricants are presented. It was found that physicochemical properties of lubricant compositions have an influence on friction coefficient value and quality of forgings.The ring compression method was used to estimate the friction coefficient value. Hydraulic press was used for the test. The comparative analysis of the investigated lubricants was carried out. The forging quality was estimated on the basis of production test. The practical recommendations were given to choose an optimal oil-based colloidal-graphite lubricant for isothermal forging of Al-based alloy.

  3. HYDROGEN-ASSISTED FRACTURE IN FORGED TYPE 304L AUSTENITIC STAINLESS STEEL

    SciTech Connect

    Switzner, Nathan; Neidt, Ted; Hollenbeck, John; Knutson, J.; Everhart, Wes; Hanlin, R.; Bergen, R.; Balch, D. K.

    2012-09-06

    Austenitic stainless steels generally have good resistance to hydrogen-assisted fracture; however, structural designs for high-pressure gaseous hydrogen are constrained by the low strength of this class of material. Forging is used to increase the low strength of austenitic stainless steels, thus improving the efficiency of structural designs. Hydrogen-assisted racture, however, depends on microstructural details associated with manufacturing. In this study, hydrogen-assisted fracture of forged type 304L austenitic stainless steel is investigated. Microstructural variation in multi-step forged 304L was achieved by forging at different rates and temperatures, and by process annealing. High internal hydrogen content in forged type 304L austenitic stainless steel is achieved by thermal precharging in gaseous hydrogen and results in as much as 50% reduction of tensile ductility.

  4. The development and production of thermo-mechanically forged tool steel spur gears

    NASA Technical Reports Server (NTRS)

    Bamberger, E. N.

    1973-01-01

    A development program to establish the feasibility and applicability of high energy rate forging procedures to tool steel spur gears was performed. Included in the study were relatively standard forging procedures as well as a thermo-mechanical process termed ausforming. The subject gear configuration utilized was essentially a standard spur gear having 28 teeth, a pitch diameter of 3.5 inches and a diametral pitch of 8. Initially it had been planned to use a high contact ratio gear design, however, a comprehensive evaluation indicated that severe forging problems would be encountered as a result of the extremely small teeth required by this type of design. The forging studies were successful in achieving gear blanks having integrally formed teeth using both standard and thermo-mechanical forging procedures.

  5. 77 FR 39997 - Heavy Forged Hand Tools, Finished or Unfinished, With or Without Handles From the People's...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-06

    ... International Trade Administration Heavy Forged Hand Tools, Finished or Unfinished, With or Without Handles From... and is amending the final results of the antidumping duty review on heavy forged hand tools, finished... Heavy Forged Hand Tools, Finished or Unfinished, With or Without Handles, From the People's Republic...

  6. 76 FR 31631 - Heavy Forged Hand Tools From China; Scheduling of Expedited Five-Year Reviews Concerning the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-01

    ... COMMISSION Heavy Forged Hand Tools From China; Scheduling of Expedited Five- Year Reviews Concerning the Antidumping Duty Orders on Heavy Forged Hand Tools From China. AGENCY: United States International Trade... determine whether revocation of the antidumping duty orders on heavy forged hand tools from China would...

  7. Ultrasonic phased arrays for nondestructive inspection of forgings

    SciTech Connect

    Wuestenberg, H.; Rotter, B. ); Klanke, H.P. ); Harbecke, D. )

    1993-06-01

    Ultrasonic examinations on large forgings like rotor shafts for turbines or components for nuclear reactors are carried out at various manufacturing stages and during in-service inspections. During the manufacture, most of the inspections are carried out manually. Special in-service conditions, such as those at nuclear pressure vessels, have resulted in the development of mechanized scanning equipment. Ultrasonic probes have improved, and well-adapted sound fields and pulse shapes and based on special imaging procedures for the representation of the reportable reflectors have been applied. Since the geometry of many forgings requires the use of a multitude of angles for the inspections in-service and during manufacture, phased-array probes can be used successfully. The main advantages of the phased-array concept, e.g. the generation of a multitude of angles with the typical increase of redundancy in detection and quantitative evaluation and the possibility to produce pictures of defect situations, will be described in this contribution.

  8. Characterization of a Viking Blade Fabricated by Traditional Forging Techniques

    NASA Astrophysics Data System (ADS)

    Vo, H.; Frazer, D.; Bailey, N.; Traylor, R.; Austin, J.; Pringle, J.; Bickel, J.; Connick, R.; Connick, W.; Hosemann, P.

    2016-12-01

    A team of students from the University of California, Berkeley, participated in a blade-smithing competition hosted by the Minerals, Metals, and Materials Society at the TMS 2015 144th annual meeting and exhibition. Motivated by ancient forging methods, the UC Berkeley team chose to fabricate our blade from historical smithing techniques utilizing naturally-occurring deposits of iron ore. This approach resulted in receiving the "Best Example of a Traditional Blade Process/Ore Smelting Technique" award for our blade named "Berkelium." First, iron-enriched sand was collected from local beaches. Magnetite (Fe3O4) was then extracted from the sand and smelted into individual high- and low-carbon steel ingots. Layers of high- and low-carbon steels were forge-welded together, predominantly by hand, to form a composite material. Optical microscopy, energy dispersive spectroscopy, and Vickers hardness mechanical testing were conducted at different stages throughout the blade-making process to evaluate the microstructure and hardness evolution during formation. It was found that the pre-heat-treated blade microstructure was composed of ferrite and pearlite, and contained many nonmetallic inclusions. A final heat treatment was performed, which caused the average hardness of the blade edge to increase by more than a factor of two, indicating a martensitic transformation.

  9. Anisotropie embrittlement in high-hardness ESR 4340 steel forgings

    NASA Astrophysics Data System (ADS)

    Olson, G. B.; Anctil, A. A.; Desisto, T. S.; Kula, E. B.

    1983-08-01

    ESR 4340 steel forgings tempered to a hardness of HRC 55 exhibit a severe loss of tensile ductility in the short transverse direction which is strain-rate and humidity dependent. The anisotropy is also reflected in blunt-notch Charpy impact energy, but is absent in the sharp-crack fracture toughness. Brittle behavior is associated with regions of smooth intergranular fracture which are aligned with microstructural banding. Scanning Auger microprobe analysis indicates some intergranular segregation of phosphorus and sulfur in these regions. The anisotropic embrittlement is attributed to an interaction of nonequilibrium segregation on solidification with local equilibrium segregation at grain boundaries during austenitizing. This produces defective regions of enhanced intergranular impurity segregation which are oriented during forging. The regions are prone to brittle fracture under impact conditions and abnormal sensitivity to environmental attack during low strain-rate deformation. A relatively sparse distribution of these defects (˜10cm-3) accounts for the discrepancy between smooth bar and blunt-notch tests vs sharp-crack tests. Isotropie properties are restored by homogenization treatment. For application of these steels at extreme hardness levels, homogenization treatment is essential.

  10. Cuprate superconductors on titanium substrates

    NASA Astrophysics Data System (ADS)

    Mitterbauer, Christina; Gritzner, Gerhard

    2007-09-01

    The applicability of titanium as substrate material for coated conductors was investigated. Titanium metal was rolled to a thickness of 1 mm and mechanically polished. The titanium sheets were oxidized in air at 1000 °C for 1 h. A dense oxide layer was formed. YBCO superconducting layers were applied to the oxidized titanium surface via screen printing from a suspension in acetone-terpineol. The YBCO layers were characterized by X-ray diffraction and by scanning electron microscopy.

  11. Computational Evaluation of the Effects of Bone Ingrowth on Bone Resorptive Remodeling after a Cementless Total Hip Arthroplasty

    NASA Astrophysics Data System (ADS)

    Jung, Duk-Young; Kang, Yu-Bong; Tsutsumi, Sadami; Nakai, Ryusuke; Ikeuchi, Ken; Sekel, Ron

    In this study, we simulated a wide cortex separation from a cementless hip prosthesis using the bone resorption remodeling method that is based on the generation of high compressive stress around the distal cortical bone. Thereafter, we estimated the effect on late migration quantities of the hip prosthesis produced by the interface state arising from bone ingrowth. This was accomplished using cortical bone remodeling over a long period of time. Two-dimensional natural hip and implanted hip FEM models were constructed with each of the following interface statements between the bone and prosthesis: (1) non-fixation, (2) proximal 1/3, (3) proximal 2/3 and (4) full-fixation. The fixation interfaces in the fully and partially porous coated regions were rigidly fixed by bony ingrowth. The non-fixation model was constructed as a critical situation, with the fibrous or bony tissue not integrated at all into the implant surface. The daily load history was generated using the three loading cases of a one-legged stance as well as abduction and adduction motions. With the natural hip and one-legged stance, the peak compressive principal stresses were found to be under the criteria value for causing bone resorption, while no implant movement occurred. The migration magnitude of the stem of the proximal 1/3 fixation model with adduction motion was much higher, reaching 6%, 11%and 21%greater than those of the non-fixation, proximal 2/3 fixation and all-fixation models, respectively. The full-fixation model showed the lowest compressive principal stress and implant movement. Thus, we concluded that the late loosening and subsequent movement of the stem in the long term could be estimated with the cortical bone remodeling method based on a high compressive stress at the bone-implant interface. The change caused at the bone-prosthesis interface by bony or fibrous tissue ingrowth constituted the major factor in determining the extent of cortical bone resorption occurring with

  12. Weld-bonded titanium structures

    NASA Technical Reports Server (NTRS)

    Vaughan, R. W.; Creedon, J. F. (Inventor)

    1976-01-01

    Structurally stronger titanium articles are produced by a weld-bonding technique comprising fastening at least two plates of titanium together using spotwelding and curing an adhesive interspersed between the spot-weld nuggets. This weld-bonding may be employed to form lap joints or to stiffen titanium metal plates.

  13. Mineral of the month: titanium

    USGS Publications Warehouse

    Gambogi, Joseph

    2004-01-01

    From paint to airplanes, titanium is important in a number of applications. Commercial production comes from titanium-bearing ilmenite, rutile and leucoxene (altered ilmenite). These minerals are used to produce titanium dioxide pigment, as well as an assortment of metal and chemical products.

  14. Titanium metal: extraction to application

    SciTech Connect

    Gambogi, Joseph; Gerdemann, Stephen J.

    2002-09-01

    In 1998, approximately 57,000 tons of titanium metal was consumed in the form of mill products (1). Only about 5% of the 4 million tons of titanium minerals consumed each year is used to produce titanium metal, with the remainder primarily used to produce titanium dioxide pigment. Titanium metal production is primarily based on the direct chlorination of rutile to produce titanium tetrachloride, which is then reduced to metal using the Kroll magnesium reduction process. The use of titanium is tied to its high strength-to-weight ratio and corrosion resistance. Aerospace is the largest application for titanium. In this paper, we discuss all aspects of the titanium industry from ore deposits through extraction to present and future applications. The methods of both primary (mining of ore, extraction, and purification) and secondary (forming and machining) operations will be analyzed. The chemical and physical properties of titanium metal will be briefly examined. Present and future applications for titanium will be discussed. Finally, the economics of titanium metal production also are analyzed as well as the advantages and disadvantages of various alternative extraction methods.

  15. Surface modification of titanium and titanium alloys by ion implantation.

    PubMed

    Rautray, Tapash R; Narayanan, R; Kwon, Tae-Yub; Kim, Kyo-Han

    2010-05-01

    Titanium and titanium alloys are widely used in biomedical devices and components, especially as hard tissue replacements as well as in cardiac and cardiovascular applications, because of their desirable properties, such as relatively low modulus, good fatigue strength, formability, machinability, corrosion resistance, and biocompatibility. However, titanium and its alloys cannot meet all of the clinical requirements. Therefore, to improve the biological, chemical, and mechanical properties, surface modification is often performed. In view of this, the current review casts new light on surface modification of titanium and titanium alloys by ion beam implantation.

  16. Tensile and creep properties of titanium-vanadium, titanium-molybdenum, and titanium-niobium alloys

    NASA Technical Reports Server (NTRS)

    Gray, H. R.

    1975-01-01

    Tensile and creep properties of experimental beta-titanium alloys were determined. Titanium-vanadium alloys had substantially greater tensile and creep strength than the titanium-niobium and titanium-molybdenum alloys tested. Specific tensile strengths of several titanium-vanadium-aluminum-silicon alloys were equivalent or superior to those of commercial titanium alloys to temperatures of 650 C. The Ti-50V-3Al-1Si alloy had the best balance of tensile strength, creep strength, and metallurgical stability. Its 500 C creep strength was far superior to that of a widely used commercial titanium alloy, Ti-6Al-4V, and almost equivalent to that of newly developed commercial titanium alloys.

  17. Using of material-technological modelling for designing production of closed die forgings

    NASA Astrophysics Data System (ADS)

    Ibrahim, K.; Vorel, I.; Jeníček, Š.; Káňa, J.; Aišman, D.; Kotěšovec, V.

    2017-02-01

    Production of forgings is a complex and demanding process which consists of a number of forging operations and, in many cases, includes post-forge heat treatment. An optimized manufacturing line is a prerequisite for obtaining prime-quality products which in turn are essential to profitable operation of a forging company. Problems may, however, arise from modifications to the manufacturing route due to changing customer needs. As a result, the production may have to be suspended temporarily to enable changeover and optimization. Using material-technological modelling, the required modifications can be tested and optimized under laboratory conditions outside the plant without disrupting the production. Thanks to material-technological modelling, the process parameters can be varied rapidly in response to changes in market requirements. Outcomes of the modelling runs include optimum parameters for the forging part’s manufacturing route, values of mechanical properties, and results of microstructure analysis. This article describes the use of material-technological modelling for exploring the impact of the amount of deformation and the rate of cooling of a particular forged part from the finish-forging temperature on its microstructure and related mechanical properties.

  18. Design and Analysis of a Forging Die for Manufacturing of Multiple Connecting Rods

    NASA Astrophysics Data System (ADS)

    Megharaj, C. E.; Nagaraj, P. M.; Jeelan Pasha, K.

    2016-09-01

    This paper demonstrates to utilize the hammer capacity by modifying the die design such that forging hammer can manufacture more than one connecting rod in a given forging cycle time. To modify the die design study is carried out to understand the parameters that are required for forging die design. By considering these parameters, forging die is designed using design modelling tool solid edge. This new design now can produce two connecting rods in same capacity hammer. The new design is required to validate by verifying complete filing of metal in die cavities without any defects in it. To verify this, analysis tool DEFORM 3D is used in this project. Before start of validation process it is require to convert 3D generated models in to. STL file format to import the models into the analysis tool DEFORM 3D. After importing these designs they are analysed for material flow into the cavities and energy required to produce two connecting rods in new forging die design. It is found that the forging die design is proper without any defects and also energy graph shows that the forging energy required to produce two connecting rods is within the limit of that hammer capacity. Implementation of this project increases the production of connecting rods by 200% in less than previous cycle time.

  19. 3D Finite Element Analysis of Spider Non-isothermal Forging Process

    NASA Astrophysics Data System (ADS)

    Niu, Ling; Wei, Wei; Wei, Kun Xia; Alexandrov, Igor V.; Hu, Jing

    2016-06-01

    The differences of effective stress, effective strain, velocity field, and the load-time curves between the spider isothermal and non-isothermal forging processes are investigated by making full use of 3D FEA, and verified by the production experiment of spider forging. Effective stress is mainly concentrated on the pin, and becomes lower closer to the front of the pin. The maximum effective strain in the non-isothermal forging is lower than that in the isothermal. The great majority of strain in the non-isothermal forging process is 1.76, which is larger than the strain of 1.31 in the isothermal forging. The maximum load required in the isothermal forging is higher than that in the non-isothermal. The maximum experimental load and deformation temperature in the spider production are in good agreement with those in the non-isothermal FEA. The results indicate that the non-isothermal 3D FEA results can guide the design of the spider forging process.

  20. Optimum Design of Forging Process Parameters and Preform Shape under Uncertainties

    NASA Astrophysics Data System (ADS)

    Repalle, Jalaja; Grandhi, Ramana V.

    2004-06-01

    Forging is a highly complex non-linear process that is vulnerable to various uncertainties, such as variations in billet geometry, die temperature, material properties, workpiece and forging equipment positional errors and process parameters. A combination of these uncertainties could induce heavy manufacturing losses through premature die failure, final part geometric distortion and production risk. Identifying the sources of uncertainties, quantifying and controlling them will reduce risk in the manufacturing environment, which will minimize the overall cost of production. In this paper, various uncertainties that affect forging tool life and preform design are identified, and their cumulative effect on the forging process is evaluated. Since the forging process simulation is computationally intensive, the response surface approach is used to reduce time by establishing a relationship between the system performance and the critical process design parameters. Variability in system performance due to randomness in the parameters is computed by applying Monte Carlo Simulations (MCS) on generated Response Surface Models (RSM). Finally, a Robust Methodology is developed to optimize forging process parameters and preform shape. The developed method is demonstrated by applying it to an axisymmetric H-cross section disk forging to improve the product quality and robustness.

  1. Development of Oxide Dispersion Strengthened (ODS) Ferritic Steel Through Powder Forging

    NASA Astrophysics Data System (ADS)

    Kumar, Deepak; Prakash, Ujjwal; Dabhade, Vikram V.; Laha, K.; Sakthivel, T.

    2017-02-01

    Oxide dispersion strengthened (ODS) ferritic steels are candidates for cladding tubes in fast breeder nuclear reactors. In this study, an 18%Cr ODS ferritic steel was prepared through powder forging route. Elemental powders with a nominal composition of Fe-18Cr-2 W-0.2Ti (composition in wt.%) with 0 and 0.35% yttria were prepared by mechanical alloying in a Simoloyer attritor under argon atmosphere. The alloyed powders were heated in a mild steel can to 1473 K under flowing hydrogen atmosphere. The can was then hot forged. Steps of sealing, degassing and evacuation are eliminated by using powder forging. Heating ODS powder in hydrogen atmosphere ensures good bonding between alloy powders. A dense ODS alloy with an attractive combination of strength and ductility was obtained after re-forging. On testing at 973 K, a loss in ductility was observed in yttria-containing alloy. The strength and ductility increased with increase in strain rate at 973 K. Reasons for this are discussed. The ODS alloy exhibited a recrystallized microstructure which is difficult to achieve by extrusion. No prior particle boundaries were observed after forging. The forged compacts exhibited isotropic mechanical properties. It is suggested that powder forging may offer several advantages over the traditional extrusion/HIP routes for fabrication of ODS alloys.

  2. Titanium alkoxide compound

    DOEpatents

    Boyle, Timothy J.

    2007-08-14

    A titanium alkoxide composition is provided, as represented by the chemical formula (OC.sub.6H.sub.5N).sub.2Ti(OC.sub.6H.sub.5NH.sub.2).sub.2. As prepared, the compound is a crystalline substance with a hexavalent titanium atom bonded to two OC.sub.6H.sub.5NH.sub.2 groups and two OC.sub.6H.sub.5N groups with a theoretical molecular weight of 480.38, comprising 60.01% C, 5.04% H and 11.66% N.

  3. Analysis of the thermo-mechanical deformations in a hot forging tool by numerical simulation

    NASA Astrophysics Data System (ADS)

    L-Cancelos, R.; Varas, F.; Martín, E.; Viéitez, I.

    2016-03-01

    Although programs have been developed for the design of tools for hot forging, its design is still largely based on the experience of the tool maker. This obliges to build some test matrices and correct their errors to minimize distortions in the forged piece. This phase prior to mass production consumes time and material resources, which makes the final product more expensive. The forging tools are usually constituted by various parts made of different grades of steel, which in turn have different mechanical properties and therefore suffer different degrees of strain. Furthermore, the tools used in the hot forging are exposed to a thermal field that also induces strain or stress based on the degree of confinement of the piece. Therefore, the mechanical behaviour of the assembly is determined by the contact between the different pieces. The numerical simulation allows to analyse different configurations and anticipate possible defects before tool making, thus, reducing the costs of this preliminary phase. In order to improve the dimensional quality of the manufactured parts, the work presented here focuses on the application of a numerical model to a hot forging manufacturing process in order to predict the areas of the forging die subjected to large deformations. The thermo-mechanical model developed and implemented with free software (Code-Aster) includes the strains of thermal origin, strains during forge impact and contact effects. The numerical results are validated with experimental measurements in a tooling set that produces forged crankshafts for the automotive industry. The numerical results show good agreement with the experimental tests. Thereby, a very useful tool for the design of tooling sets for hot forging is achieved.

  4. Snake River Plain FORGE Well Data for INEL-1

    DOE Data Explorer

    Robert Podgorney

    1979-03-01

    Well data for the INEL-1 well located in eastern Snake River Plain, Idaho. This data collection includes caliper logs, lithology reports, borehole logs, temperature at depth data, neutron density and gamma data, full color logs, fracture analysis, photos, and rock strength parameters for the INEL-1 well. This collection of data has been assembled as part of the site characterization data used to develop the conceptual geologic model for the Snake River Plain site in Idaho, as part of phase 1 of the Frontier Observatory for Research in Geothermal Energy (FORGE) initiative. They were assembled by the Snake River Geothermal Consortium (SRGC), a team of collaborators that includes members from national laboratories, universities, industry, and federal agencies, lead by the Idaho National Laboratory (INL).

  5. Science Education and Outreach: Forging a Path to the Future

    NASA Astrophysics Data System (ADS)

    Manning, James G.

    2009-05-01

    The International Year of Astronomy and the Year of Science provide singular opportunities to focus public attention on science in general and the universe in particular in 2009. But what happens on January 1, 2010? How can the science and science education communities build on the initiatives and successes of 2009 to create sustainable programs and efforts to continue to advance science education and literacy objectives for the longer term? The presenter will relate how these questions will be addressed at the annual meeting of the Astronomical Society of the Pacific in Millbrae, California, September 12-16, and how the meeting will provide an opportunity for the science, astronomy, and science education and outreach communities to contribute to the discussion and to share their answers and perspectives with the larger community, and to identify ways in which we can forge that future path together.

  6. Crack toughness evaluation of hot pressed and forged beryllium

    NASA Technical Reports Server (NTRS)

    Jones, M. H.; Bubsey, R. T.; Brown, W. F., Jr.

    1971-01-01

    Beryllium fracture toughness test specimens were fatigue cracked using reversed cycling with a compression load two to three times the tension load. In worked beryllium, textures may be produced which result in fatigue cracks that are out of plane with the starter notch. Specimens of hot pressed stock exhibited load displacement records which were nonlinear throughout their course. Fracture specimens of both hot pressed and forged stock showed essentially no reduction of thickness and the fracture surfaces were flat and normal to the load axis. However, the stress intensity factor at maximum load increased with decreasing thickness. Load-displacement and electric potential records for the hot pressed beryllium specimens exhibited several anomalies such as negative residual crack mouth displacements and a decrease in electrical potential with increasing load.

  7. Experimentation and numerical modeling of forging induced bending (FIB) process

    NASA Astrophysics Data System (ADS)

    Naseem, S.; van den Boogaard, A. H.

    2016-10-01

    Accurate prediction of the final shape using numerical modeling has been a top priority in the field of sheet and bulk forming. Better shape prediction is the result of a better estimation of the physical stress and strain state. For experimental and numerical investigations of such estimations, simple benchmark processes are used. In this paper a benchmark process involving forging (flattening) of sheet metal between punch and die with negative clearance is proposed. The introduced material flow results in bending. Easy measurability of the angle of this bend makes this process suitable for validation purpose. Physical experiments are performed to characterize this bending angle due to flattening. Furthermore a numerical model is developed to capture this phenomenon. The main focus of this paper is the validation of the numerical model in terms of accurate prediction of the physical results.

  8. Snake River Plain FORGE Well Data for WO-2

    DOE Data Explorer

    Robert Podgorney

    1991-07-29

    Well data for the WO-2 well located in eastern Snake River Plain, Idaho. This data collection includes lithology reports, borehole logs, temperature at depth data, neutron density and gamma data, and rock strength parameters for the WO-2 well. This collection of data has been assembled as part of the site characterization data used to develop the conceptual geologic model for the Snake River Plain site in Idaho, as part of phase 1 of the Frontier Observatory for Research in Geothermal Energy (FORGE) initiative. They were assembled by the Snake River Geothermal Consortium (SRGC), a team of collaborators that includes members from national laboratories, universities, industry, and federal agencies, lead by the Idaho National Laboratory (INL).

  9. Optimizing noise control strategy in a forging workshop.

    PubMed

    Razavi, Hamideh; Ramazanifar, Ehsan; Bagherzadeh, Jalal

    2014-01-01

    In this paper, a computer program based on a genetic algorithm is developed to find an economic solution for noise control in a forging workshop. Initially, input data, including characteristics of sound sources, human exposure, abatement techniques, and production plans are inserted into the model. Using sound pressure levels at working locations, the operators who are at higher risk are identified and picked out for the next step. The program is devised in MATLAB such that the parameters can be easily defined and changed for comparison. The final results are structured into 4 sections that specify an appropriate abatement method for each operator and machine, minimum allowance time for high-risk operators, required damping material for enclosures, and minimum total cost of these treatments. The validity of input data in addition to proper settings in the optimization model ensures the final solution is practical and economically reasonable.

  10. Physics and Technological Training in Bulgarian Forge Craft

    NASA Astrophysics Data System (ADS)

    Petkova, Petya N.; Velcheva, Keranka G.

    2010-01-01

    The contemporary world regenerates and preserves the traditions of decorative—applied art and the national crafts. This brings up young generation and helps them to uncover the sources of national culture. In the commonly educational system the technological training realizes succession of new methods for national and applied art. The aim is examination of the national crafts as technological processes for cultivation of different metal constructions. There are enforced physical laws here. Seven basic groups of forging methods consider in Bulgarian tradition craft as heat treatment, plastic deformation and applying of different tensions. This gives information about morphology of construction after applying of stress, enlarging or decreasing of the linear sizes, structure change and the change of physical and mechanical properties.

  11. Laser-dispersing of forging tools using AlN-ceramics

    NASA Astrophysics Data System (ADS)

    Noelke, C.; Luecke, M.; Kaierle, S.; Wesling, V.; Overmeyer, L.

    2014-02-01

    Forging tools for aluminum work pieces show an increased adhesive wear due to cold welding during the forging process. Laser dispersing offers at this point a great potential to fabricate protective layers or tracks with tailored properties that reduce abrasive or adhesive wear at the surface of highly stressed components. Using different process strategies, four metal ceramic compounds applied on two substrate geometries were investigated regarding their structural and mechanical properties and their performance level. The subsequent forging tests have pointed out a positive effect and less adhesive residuals on the laser dispersed tool surface.

  12. Characterization of large 2219 aluminum alloy hand forgings for the space shuttle solid rocket booster

    NASA Technical Reports Server (NTRS)

    Brennecke, M. W.

    1978-01-01

    The mechanical properties, including fracture toughness, and stress corrosion properties of four types of 2219-T852 aluminum alloy hand forgings are presented. Weight of the forgings varied between 450 and 3500 lb at the time of heat treatment and dimensions exceeded the maximum covered in existing specifications. The forgings were destructively tested to develop reliable mechanical property data to replace estimates employed in the design of the Space Shuttle Solid Rocket Booster (SRB) and to establish minimum guaranteed properties for structural refinement and for entry into specification revisions. The report summarizes data required from the forgers and from the SRB Structures contractor.

  13. Assessment of NASA Dual Microstructure Heat Treatment Method for Multiple Forging Batch Heat Treatment

    NASA Technical Reports Server (NTRS)

    Gayda, John (Technical Monitor); Lemsky, Joe

    2004-01-01

    NASA dual microstructure heat treatment technology previously demonstrated on single forging heat treat batches of a generic disk shape was successfully demonstrated on a multiple disk batch of a production shape component. A group of four Rolls-Royce Corporation 3rd Stage AE2100 forgings produced from alloy ME209 were successfully dual microstructure heat treated as a single heat treat batch. The forgings responded uniformly as evidenced by part-to-part consistent thermocouple recordings and resultant macrostructures, and from ultrasonic examination. Multiple disk DMHT processing offers a low cost alternative to other published dual microstructure processing techniques.

  14. Hot Superplastic Powder Forging for Transparent nanocrystalline Ceramics

    SciTech Connect

    Cannon, W. Roger

    2006-05-22

    The program explored a completely new, economical method of manufacturing nanocrystalline ceramics, Hot Superplastic Powder Forging (HSPF). The goal of the work was the development of nanocrystalline/low porosity optically transparent zirconia/alumina. The high optical transparency should result from lack of grain boundary scattering since grains will be smaller than one tenth the wavelength of light and from elimination of porosity. An important technological potential for this process is manufacturing of envelopes for high-pressure sodium vapor lamps. The technique for fabricating monolithic nanocrystalline material does not begin with powder whose particle diameter is <100 nm as is commonly done. Instead it begins with powder whose particle diameter is on the order of 10-100 microns but contains nanocrystalline crystallites <<100 nm. Spherical particles are quenched from a melt and heat treated to achieve the desired microstructure. Under a moderate pressure within a die or a mold at temperatures of 1100C to 1300C densification is by plastic flow of superplastic particles. A nanocrystalline microstructure results, though some features are greater than 100nm. It was found, for instance, that in the fully dense Al2O3-ZrO2 eutectic specimens that a bicontinuous microstructure exists containing <100 nm ZrO2 particles in a matrix of Al2O3 grains extending over 1-2 microns. Crystallization, growth, phase development and creep during hot pressing and forging were studied for several compositions and so provided some details on development of polycrystalline microstructure from heating quenched ceramics.

  15. Non-isothermal deformation of gamma titanium aluminide

    SciTech Connect

    Mohan, B.; Srinivasan, R.; Weiss, I.

    1995-12-31

    Gamma titanium aluminide is being considered as a material for use in internal combustion (IC) engine valves. At the present time IC engine valves are made from steel by a combination of extrusion and forging operations using a heated workpiece and relatively cold dies. In order to develop similar deformation processing technologies for gamma titanium aluminide, limits of formability under different processing conditions need to be established. Non-isothermal deformation with heated dies were carried out on samples of materials which had been processed by different routes to yield microstructures with grain sizes in the range of 3 to 10,000 {micro}m. Processing parameters such as strain rate, specimen temperature, total strain, and type of lubricant were varied in order to establish processing windows for uniform deformation of the different materials. During non-isothermal forming, the highest strain rate for uniform deformation is about 0.1 s{sup {minus}1}. Strain rates slower than 0.01 s{sup {minus}1} result in extensive chilling of the workpiece resulting in fracture. The maximum amount of deformation that could be obtained was a 40% reduction in height (strain of 0.5). The type of lubricant used plays a significant role in the formation of cracks on the specimen at the specimen/die interfaces.

  16. Mid-Term Outcomes and Complications with Cementless Distal Locking Hip Revision Stem with Hydroxyapatite Coating for Proximal Bone Defects and Fractures.

    PubMed

    Carrera, Lluis; Haddad, Sleiman; Minguell, Joan; Amat, Carles; Corona, Pablo S

    2015-06-01

    We revised the first 100 revision total hip arthroplasties using a cementless distal locking revision stem conducted in our referral centre. Average follow-up was 9.2 years (range: 5.5-12 years). Harris Hip Score improved from 42.5 to 81.6, and none had thigh pain at last follow-up. No significant stress shielding, osteolysis, or radiologic loosening was found. All patients showed radiological evidence of secondary implant osseointegration. Overall survival was 97% with three patients being revised: two stem ruptures and one subsidence. We could trace these complications to technical errors. These findings suggest that a diaphyseal fixation of the revision stem with distal locking can provide the needed primary axial and rotational stability of the prosthesis. This would allow further bony ingrowth, enhanced by the hydroxyapatite coating.

  17. Sorting Titanium Welding Rods

    NASA Technical Reports Server (NTRS)

    Ross, W. D., Jr.; Brown, R. L.

    1985-01-01

    Three types of titanium welding wires identified by their resistance to current flow. Welding-wire tester quickly identifies unknown titaniumalloy wire by touching wire with test probe, and comparing meter response with standard response. Before touching wire, tip of test probe dipped into an electrolyte.

  18. The effect of abductor muscle and anterior-posterior hip contact load simulation on the in-vitro primary stability of a cementless hip stem

    PubMed Central

    2010-01-01

    Background In-vitro mechanical tests are commonly performed to assess pre-clinically the effect of implant design on the stability of hip endoprostheses. There is no standard protocol for these tests, and the forces applied vary between studies. This study examines the effect of the abductor force with and without application of the anterior-posterior hip contact force in the in-vitro assessment of cementless hip implant stability. Methods Cementless stems (VerSys Fiber Metal) were implanted in twelve composite femurs which were divided into two groups: group 1 (N = 6) was loaded with the hip contact force only, whereas group 2 (N = 6) was additionally subjected to an abductor force. Both groups were subjected to the same cranial-caudal hip contact force component, 2.3 times body weight (BW) and each specimen was subjected to three levels of anterior-posterior hip contact load: 0, -0.1 to 0.3 BW (walking), and -0.1 to 0.6 BW (stair climbing). The implant migration and micromotion relative to the femur was measured using a custom-built system comprised of 6 LVDT sensors. Results Substantially higher implant motion was observed when the anterior-posterior force was 0.6BW compared to the lower anterior-posterior load levels, particularly distally and in retroversion. The abductor load had little effect on implant motion when simulating walking, but resulted in significantly less motion than the hip contact force alone when simulating stair climbing. Conclusions The anterior-posterior component of the hip contact load has a significant effect on the axial motion of the stem relative to the bone. Inclusion of the abductor force had a stabilizing effect on the implant motion when simulating stair climbing. PMID:20576151

  19. The influence of contact ratio and its location on the primary stability of cementless total hip arthroplasty: A finite element analysis.

    PubMed

    Reimeringer, M; Nuño, N

    2016-05-03

    Cementless hip stems are fixed to the surrounding bone by means of press-fit. To ensure a good press-fit, current surgical technique specifies an under-reaming of the bone cavity using successively larger broaches. Nevertheless, this surgical technique is inaccurate. Several studies show that the contact ratio (percentage of stem interface in contact with bone) achieved after surgery can vary between 20% and 95%. Therefore, this study aimed to investigate the influence of the contact ratio and its location on the primary stability of a cementless total hip arthroplasty using finite element analysis. A straight tapered femoral stem implanted in a composite bone was subjected to stair climbing. Micromotion of 7600 nodes at the stem-bone interface was computed for different configurations of contact ratios between 2% and 98%) along the hip stem. Considering the 15 configurations evaluated, the average micromotion ranges between 27μm and 54μm. The percentage of the porous interface of the stem having micromotion below 40μm that allows bone ingrowth range between 25-57%. The present numerical study shows that full contact (100%) between stem and bone is not necessary to obtain a good primary stability. The stem primary stability is influenced by both the contact ratio and its location. Several configurations with contact ratio lower than 100% and involving either the proximal or the cortical contact provide better primary stability than the full contact configuration. However, with contact ratio lower than 40%, the stem should be in contact with cortical bone to ensure a good primary stability.

  20. Bioactive macroporous titanium surface layer on titanium substrate.

    PubMed

    Kim, H M; Kokubo, T; Fujibayashi, S; Nishiguchi, S; Nakamura, T

    2000-12-05

    A macroporous titanium surface layer is often formed on titanium and titanium alloy implants for morphological fixation of the implants to bone via bony ingrowth into the porous structure. The surface of titanium metal was recently shown to become highly bioactive by being subjected to 5.0 M-NaOH treatment at 60 degrees C for 24 h and subsequent heat treatment at 600 degrees C for 1 h. In the present study, the NaOH and heat treatments were applied to a macroporous titanium surface layer formed on titanium substrate by a plasma spraying method. The NaOH and heat treatments produced an uniform amorphous sodium titanate layer on the surface of the porous titanium. The sodium titanate induced a bonelike apatite formation in simulated body fluid at an early soaking period, whereby the apatite layer grew uniformly along the surface and cross-sectional macrotextures of the porous titanium. This indicates that the NaOH and heat treatments lead to a bioactive macroporous titanium surface layer on titanium substrate. Such a bioactive macroporous layer on an implant is expected not only to enhance bony ingrowth into the porous structure, but also to provide a chemical integration with bone via apatite formation on its surface in the body.

  1. A comparative study of zinc, magnesium, strontium-incorporated hydroxyapatite-coated titanium implants for osseointegration of osteopenic rats.

    PubMed

    Tao, Zhou-Shan; Zhou, Wan-Shu; He, Xing-Wen; Liu, Wei; Bai, Bing-Li; Zhou, Qiang; Huang, Zheng-Liang; Tu, Kai-kai; Li, Hang; Sun, Tao; Lv, Yang-Xun; Cui, Wei; Yang, Lei

    2016-05-01

    Surface modification techniques have been applied to generate titanium implant surfaces that promote osseointegration for the implants in cementless arthroplasty. However, its effect is not sufficient for osteoporotic bone. Zinc (Zn), magnesium (Mg), and strontium (Sr) present a beneficial effect on bone growth, and positively affect bone regeneration. The aim of this study was to confirm the different effects of the fixation strength of Zn, Mg, Sr-substituted hydroxyapatite-coated (Zn-HA-coated, Mg-HA-coated, Sr-HA-coated) titanium implants via electrochemical deposition in the osteoporotic condition. Female Sprague-Dawley rats were used for this study. Twelve weeks after bilateral ovariectomy, all animals were randomly divided into four groups: group HA; group Zn-HA; group Mg-HA and group Sr-HA. Afterwards, all rats from groups HA, Zn-HA, Mg-HA and Sr-HA received implants with hydroxyapatite containing 0%, 10% Zn ions, 10% Mg ions, and 10% Sr ions. Implants were inserted bilaterally in all animals until death at 12 weeks. The bilateral femurs of rats were harvested for evaluation. All treatment groups increased new bone formation around the surface of titanium rods and push-out force; group Sr-HA showed the strongest effects on new bone formation and biomechanical strength. Additionally, there are significant differences in bone formation and push-out force was observed between groups Zn-HA and Mg-HA. This finding suggests that Zn, Mg, Sr-substituted hydroxyapatite coatings can improve implant osseointegration, and the 10% Sr coating exhibited the best properties for implant osseointegration among the tested coatings in osteoporosis rats.

  2. Establishment of a Process for Creep Forging Aluminum Alloy Weapon Components

    DTIC Science & Technology

    1978-04-01

    the important powder particle character- istics are mean particle size and size distribution, dendritic cell size and pattern, internal voids , and...Geometry Forging No. 26 (Fig. 53) showed excellent die filling except for a slight underfill at the tallest rib. Minor cracking also occurred over a small...Much cracking and underfill In rib detal1. 0.2 750 400 1 Some cracking Trimmed weight, 3.0 lb. 0.1 830 150 - Forged

  3. Military Process Specification for Type 46XX Powder-Forged Weapon Components

    DTIC Science & Technology

    1985-08-20

    one with low carbon or carburizing steels (Figure 18). Fracture Toughness Only one paper contained fracture toughness data for P/F 10XX steels . The...201-213. 8. Brown, G. T., "The Core ’Properties of a Range of Powder-Forged Steels ’ for Carburizing Applications," Powder Metallurgy, vol. 20, no...621205H84001, Dover, NJ: ARRADC0M, October 1980. Smith, A. 0., "Hardenability of Forged Alloy Steel Powders for Carburizing Ap- plications," Inland

  4. Numerical analysis of rheological and tribological behavior influence on 16MnCr5 forging fibering

    NASA Astrophysics Data System (ADS)

    Gavrus, A.; Pintilie, D.; Nedelcu, R.

    2016-10-01

    The present research work is focus on the influence of the rheological constitutive equation and friction law formulation on 16MnCr5 forging fibering. Numerical analysis using FE Forge® and Abaqus code show the importance of the rheological softening terms on the metals fibers morphology and position coordinate. Calibration of friction law and sensitivity of softening parameters corresponding to a Hansel-Spittel rheological equation have been studied.

  5. Development of strategies for saving energy by temperature reduction in warm forging processes

    NASA Astrophysics Data System (ADS)

    Varela, Sonia; Santos, Maite; Vadillo, Leire; Idoyaga, Zuriñe; Valbuena, Óscar

    2016-10-01

    This paper is associated to the European policy of increasing efficiency in raw material and energy usage. This policy becomes even more important in sectors consuming high amount of resources, like hot forging industry, where material costs sums up to 50% of component price and energy ones are continuously raising. The warm forging shows a clear potential of raw material reduction (near-net-shape components) and also of energy saving (forging temperature under 1000°C). However and due to the increment of the energy costs, new solutions are required by the forging sector in order to reduce the temperature below 900°C. The reported research is based on several approaches to reduce the forging temperature applied to a flanged shaft of the automotive sector as demonstration case. The developed investigations have included several aspects: raw material, process parameters, tools and dies behavior during forging process and also metallographic evaluation of the forged parts. This paper summarizes analysis of the ductility and the admissible forces of the flanged shaft material Ck45 in as-supplied state (as-rolled) and also in two additional heat treated states. Hot compression and tensile tests using a GLEEBLE 3800C Thermo mechanical simulator have been performed pursuing this target. In the same way, a coupled numerical model based on Finite Element Method (FEM) has been developed to predict the material flow, the forging loads and the stresses on the tools at lower temperature with the new heat treatments of the raw material. In order to validate the previous development, experimental trials at 850 °C and 750 °C were carried out in a mechanical press and the results were very promising.

  6. Nine percent nickel steel heavy forging weld repair study. [National Transonic Wind Tunnel fan components

    NASA Technical Reports Server (NTRS)

    Young, C. P., Jr.; Gerringer, A. H.; Brooks, T. G.; Berry, R. F., Jr.

    1978-01-01

    The feasibility of making weld repairs on heavy section 9% nickel steel forgings such as those being manufactured for the National Transonic Facility fan disk and fan drive shaft components was evaluated. Results indicate that 9% nickel steel in heavy forgings has very good weldability characteristics for the particular weld rod and weld procedures used. A comparison of data for known similar work is included.

  7. Deformation, recrystallization, strength, and fracture of press-forged ceramic crystals.

    NASA Technical Reports Server (NTRS)

    Rice, R. W.

    1972-01-01

    Sapphire and ruby were very difficult to press-forge because they deformed without cracking only in a limited temperature range before they melted. Spinel crystals were somewhat easier and MgO, CaO, and TiC crystals much easier to forge. The degree of recrystallization that occurred during forging (which was related to the ease and type of slip intersections) varied from essentially zero in Al2O3 to complete (i.e., random polycrystalline bodies were produced) in CaO. Forging of bi- and polycrystalline bodies produced incoherent bodies as a result of grain-boundary sliding. Strengths of the forged crystals were comparable to those of dense polycrystalline bodies of similar grain size. However, forged and recrystallized CaO crystals were ductile at lower temperatures than dense hot-pressed CaO. This behavior is attributed to reduced grain-boundary impurities and porosity. Fracture origins could be located, indicating that fracture in the CaO occurs internally as a result of surface work hardening caused by machining.-

  8. FEM Analysis and Experimental Verification of the Integral Forging Process for AP1000 Primary Coolant Pipe

    NASA Astrophysics Data System (ADS)

    Wang, Shenglong; Yu, Xiaoyi; Yang, Bin; Zhang, Mingxian; Wu, Huanchun

    2016-10-01

    AP1000 primary coolant pipes must be manufactured by integral forging technology according to the designer—Westinghouse Electric Co. The characteristics of these large, special-shaped pipes create nonuniform temperatures, effective stress, and effective strain during shaping of the pipes. This paper presents a three-dimensional finite element simulation (3D FEM) of the integral forging process, and qualitatively evaluates the likelihood of forging defects. By analyzing the evolution histories of the three field variables, we concluded that the initial forging temperature should be strictly controlled within the interval 1123 K to 1423 K (850 °C to 1150 °C) to avoid second-phase precipitation. In the hard deformation zones, small strains do not contribute to recrystallization resulting in coarse grains. Conversely, in the free deformation zone, the large strains can contribute to the dynamic recrystallization, favoring grain refinement and closure of voids. Cracks are likely to appear, however, on the workpiece surface when forging leads to large deformations. Based on the simulation results, an eligible workpiece with good mechanical properties, few macroscopic defects, and favorable grain size has been successfully forged by experiments at an industrial scale, which validates the FEM simulation.

  9. Study on application of color filters in vision system of hot forgings

    NASA Astrophysics Data System (ADS)

    Bi, Chao; Fang, Jianguo; Li, Di; Qu, Xinghua

    2016-10-01

    In order to improve the quality and efficiency of forging process, it needs to execute on-line dimensional measurement of the forgings. In the paper, a laboratory color vision measuring system is set up and the combination of digital and physical filtering is adopted to improve the image quality based on the radiation characteristics of high-temperature forgings. The digital filtering technology is a kind of image processing methods, in which the R component of the forging image is removed. While, the physical filtering technology is achieved by optical filters installed in front of the CCD, in which strong self-emitted radiation from the hot parts can be filtered out. In order to evaluate the image quality, the image contrast is applied, which is generally defined as the difference value between average gray scale of object region and that of background region. In the experiments, image contrast derived with filters at different sample points set from 800°C to 1200°C is compared to determine the optimal scheme of filters to be selected. Results of experiments indicate that the application effect of filters is dissimilar when the forging is in different temperature ranges. Through comparison, the optimal selection scheme of filters is determined to derive high quality image of forgings at different temperatures, which lays a solid foundation for the subsequent image processing.

  10. Welded Titanium Case for Space-Probe Rocket Motor

    NASA Technical Reports Server (NTRS)

    Brothers, A. J.; Boundy, R. A.; Martens, H. E.; Jaffe, L. D.

    1959-01-01

    components used to make the stainless steel and the 6A1--4V titanium alloy cases. The forward dome and aft fitting for the stainless steel assembly were fabricated from a combination of forged, spun and machined parts.. In order to facilitate the fabrication of the titanium alloy motor ) these components were machined from a large-diameter billet.

  11. West Flank Coso, CA FORGE 3D temperature model

    SciTech Connect

    Doug Blankenship

    2016-03-01

    x,y,z data of the 3D temperature model for the West Flank Coso FORGE site. Model grid spacing is 250m. The temperature model for the Coso geothermal field used over 100 geothermal production sized wells and intermediate-depth temperature holes. At the near surface of this model, two boundary temperatures were assumed: (1) areas with surface manifestations, including fumaroles along the northeast striking normal faults and northwest striking dextral faults with the hydrothermal field, a temperature of ~104˚C was applied to datum at +1066 meters above sea level elevation, and (2) a near-surface temperature at about 10 meters depth, of 20˚C was applied below the diurnal and annual conductive temperature perturbations. These assumptions were based on heat flow studies conducted at the CVF and for the Mojave Desert. On the edges of the hydrothermal system, a 73˚C/km (4˚F/100’) temperature gradient contour was established using conductive gradient data from shallow and intermediate-depth temperature holes. This contour was continued to all elevation datums between the 20˚C surface and -1520 meters below mean sea level. Because the West Flank is outside of the geothermal field footprint, during Phase 1, the three wells inside the FORGE site were incorporated into the preexisting temperature model. To ensure a complete model was built based on all the available data sets, measured bottom-hole temperature gradients in certain wells were downward extrapolated to the next deepest elevation datum (or a maximum of about 25% of the well depth where conductive gradients are evident in the lower portions of the wells). After assuring that the margins of the geothermal field were going to be adequately modelled, the data was contoured using the Kriging method algorithm. Although the extrapolated temperatures and boundary conditions are not rigorous, the calculated temperatures are anticipated to be within ~6˚C (20˚F), or one contour interval, of the

  12. Titanium Honeycomb Panel Testing

    NASA Technical Reports Server (NTRS)

    Richards, W. Lance; Thompson, Randolph C.

    1996-01-01

    Thermal-mechanical tests were performed on a titanium honeycomb sandwich panel to experimentally validate the hypersonic wing panel concept and compare test data with analysis. Details of the test article, test fixture development, instrumentation, and test results are presented. After extensive testing to 900 deg. F, non-destructive evaluation of the panel has not detected any significant structural degradation caused by the applied thermal-mechanical loads.

  13. Comparison of pitting fatigue life of ausforged and standard forged AISI M-50 and AISI 9310 spur gears

    NASA Technical Reports Server (NTRS)

    Townsend, D. P.; Bamberger, E. N.; Zaretsky, E. V.

    1975-01-01

    Standard forged and ausforged spur gears made of vacuum-induction-melted, consumable-electrode, vacuum-arc-remelted AISI M-50 steel were tested under conditions that produced fatigue pitting. The gears were 8.89 cm (3.5 in.) in pitch diameter and had tip relief. The M-50 standard forged and ausforged test results were compared with each other. They were then compared with results for machined vacuum-arc-remelted AISI 9310 gears tested under identical conditions. Both types of M-50 gears had lives approximately five times that of the 9310 gears. The life at which 10 percent of the M-50 ausforged gears failed was slightly less than that at which the M-50 standard forged gears failed. The ausforged gears had a slightly greater tendency to fail by tooth fracture than did the standard forged gears, most likely because of the better forging and grain flow pattern of standard forged gears.

  14. Titanium: light, strong, and white

    USGS Publications Warehouse

    Woodruff, Laurel; Bedinger, George

    2013-01-01

    Titanium (Ti) is a strong silver-gray metal that is highly resistant to corrosion and is chemically inert. It is as strong as steel but 45 percent lighter, and it is twice as strong as aluminum but only 60 percent heavier. Titanium dioxide (TiO2) has a very high refractive index, which means that it has high light-scattering ability. As a result, TiO2 imparts whiteness, opacity, and brightness to many products. ...Because of the unique physical properties of titanium metal and the whiteness provided by TiO2, titanium is now used widely in modern industrial societies.

  15. Titanium fasteners. [for aircraft industry

    NASA Technical Reports Server (NTRS)

    Phillips, J. L.

    1972-01-01

    Titanium fasteners are used in large quantities throughout the aircraft industry. Most of this usage is in aluminum structure; where titanium structure exists, titanium fasteners are logically used as well. Titanium fasteners offer potential weight savings to the designer at a cost of approximately $30 per pound of weight saved. Proper and least cost usage must take into consideration type of fastener per application, galvanic couples and installation characteristics of protective coatings, cosmetic appearance, paint adhesion, installation forces and methods available and fatigue performance required.

  16. Cementless total knee arthroplasty

    PubMed Central

    Risitano, Salvatore; Sabatini, Luigi; Giachino, Matteo; Agati, Gabriele; Massè, Alessandro

    2016-01-01

    Interest for uncemented total knee arthroplasty (TKA) has greatly increased in recent years. This technique, less used than cemented knee replacement in the last decades, sees a revival thanks an advance in prosthetic design, instrumentation and operative technique. The related literature in some cases shows conflicting data on survival and on the revision’s rate, but in most cases a success rate comparable to cemented TKA is reported. The optimal fixation in TKA is a subject of debate with the majority of surgeons favouring cemented fixation. PMID:27162779

  17. Anisotropic embrittlement in high-hardness ESR 4340 steel forgings

    SciTech Connect

    Olson, G.B.; Anctil, A.A.; DeSisto, T.S.; Kula, E.B.

    1983-08-01

    ESR 4340 steel forgings tempered to a hardness of HRC 55 exhibit a severe loss of tensile ductility in the short transverse direction which is strain-rate and humidity dependent. The anisotropy is also reflected in blunt-notch Charpy impact energy, but is absent in the sharp-crack fracture toughness. Brittle behavior is associated with regions of smooth intergranular fracture aligned with microstructural banding Scanning Auger microprobe analysis indicates intergranular segregation of phosphorus and sulfur. The anisotropic embrittlement is attributed to an interaction of nonequilibrium segregation on solidification with local equilibrium segregation at grain boundaries during austenitizing. The regions are prone to brittle fracture under impact conditions and abnormal sensitivity to environmental attack during low strain-rate deformation. A relatively sparse distribution of these defects accounts for the discrepancy between smooth bar and blunt-notch tests vs sharp-crack tests. Isotropic properties are restored by homogenization treatment. For application of these steels at extreme hardness levels, homogenization treatment is essential.

  18. Movement Synchrony Forges Social Bonds across Group Divides

    PubMed Central

    Tunçgenç, Bahar; Cohen, Emma

    2016-01-01

    Group dynamics play an important role in the social interactions of both children and adults. A large amount of research has shown that merely being allocated to arbitrarily defined groups can evoke disproportionately positive attitudes toward one's in-group and negative attitudes toward out-groups, and that these biases emerge in early childhood. This prompts important empirical questions with far-reaching theoretical and applied significance. How robust are these inter-group biases? Can biases be mitigated by behaviors known to bond individuals and groups together? How can bonds be forged across existing group divides? To explore these questions, we examined the bonding effects of interpersonal synchrony on minimally constructed groups in a controlled experiment. In-group and out-group bonding were assessed using questionnaires administered before and after a task in which groups performed movements either synchronously or non-synchronously in a between-participants design. We also developed an implicit behavioral measure, the Island Game, in which physical proximity was used as an indirect measure of interpersonal closeness. Self-report and behavioral measures showed increased bonding between groups after synchronous movement. Bonding with the out-group was significantly higher in the condition in which movements were performed synchronously than when movements were performed non-synchronously between groups. The findings are discussed in terms of their importance for the developmental social psychology of group dynamics as well as their implications for applied intervention programs. PMID:27303341

  19. DESIGN MECHANICAL PROPERTIES, FRACTURE TOUGHNESS, FATIGUE PROPERTIES, EXFOLIATION AND STRESS-CORROSION RESISTANCE OF 7050 SHEET, PLATE, HAND FORGINGS, DIE FORGINGS AND EXTRUSIONS

    DTIC Science & Technology

    1975-07-01

    Cracking, of Stress- Relieved Stretched Aluminum Alloy Extrusions", Technical Report AFML-TR-68-34, Fabruary 1968. 11. D. J. Brownhill, C. F. Babilon , 0. E...Rates of Stress-Relieved Aluminum Alloy Hand Forgings", Technical Report AFML-TR-70-10, February 1970. 12. C. F. Babilon , R. H. Wygonik, G. E

  20. Titanium Optics for Ion Thrusters

    NASA Technical Reports Server (NTRS)

    Soulas, George C.; Haag, Thomas W.; Patterson, Michael J.; Rawlin, Vincent K.

    1999-01-01

    Ion thruster total impulse capability is limited, in part, by accelerator grid sputter erosion. A development effort was initiated to identify a material with a lower accelerator grid volumetric sputter erosion rate than molybdenum, but that could utilize the present NSTAR thruster grid design and fabrication techniques to keep development costs low, and perform as well as molybdenum optics. After comparing the sputter erosion rates of several atomic materials to that of molybdenum at accelerator voltages, titanium was found to offer a 45% reduction in volumetric erosion rates. To ensure that screen grid sputter erosion rates are not higher at discharge chamber potentials, titanium and molybdenum sputter erosion rates were measured at these potentials. Preliminary results showed only a slightly higher volumetric erosion rate for titanium, so that screen grid erosion is insignificant. A number of material, thermal, and mechanical properties were also examined to identify any fabrication, launch environment, and thruster operation issues. Several titanium grid sets were successfully fabricated. A titanium grid set was mounted onto an NSTAR 30 cm engineering model ion thruster and tested to determine optics performance. The titanium optics operated successfully over the entire NSTAR power range of 0.5 to 2.3 kW. Differences in impingement-limited perveances and electron backstreaming limits were found to be due to a larger cold gap for the titanium optics. Discharge losses for titanium grids were lower than those for molybdenum, likely due to a slightly larger titanium screen grid open area fraction. Radial distributions of beam current density with titanium optics were very similar to those with molybdenum optics at all power levels. Temporal electron backstreaming limit measurements showed that titanium optics achieved thermal equilibrium faster than molybdenum optics.

  1. Making randomised trials more efficient: report of the first meeting to discuss the Trial Forge platform.

    PubMed

    Treweek, Shaun; Altman, Doug G; Bower, Peter; Campbell, Marion; Chalmers, Iain; Cotton, Seonaidh; Craig, Peter; Crosby, David; Davidson, Peter; Devane, Declan; Duley, Lelia; Dunn, Janet; Elbourne, Diana; Farrell, Barbara; Gamble, Carrol; Gillies, Katie; Hood, Kerry; Lang, Trudie; Littleford, Roberta; Loudon, Kirsty; McDonald, Alison; McPherson, Gladys; Nelson, Annmarie; Norrie, John; Ramsay, Craig; Sandercock, Peter; Shanahan, Daniel R; Summerskill, William; Sydes, Matt; Williamson, Paula; Clarke, Mike

    2015-06-05

    Randomised trials are at the heart of evidence-based healthcare, but the methods and infrastructure for conducting these sometimes complex studies are largely evidence free. Trial Forge ( www.trialforge.org ) is an initiative that aims to increase the evidence base for trial decision making and, in doing so, to improve trial efficiency.This paper summarises a one-day workshop held in Edinburgh on 10 July 2014 to discuss Trial Forge and how to advance this initiative. We first outline the problem of inefficiency in randomised trials and go on to describe Trial Forge. We present participants' views on the processes in the life of a randomised trial that should be covered by Trial Forge.General support existed at the workshop for the Trial Forge approach to increase the evidence base for making randomised trial decisions and for improving trial efficiency. Agreed upon key processes included choosing the right research question; logistical planning for delivery, training of staff, recruitment, and retention; data management and dissemination; and close down. The process of linking to existing initiatives where possible was considered crucial. Trial Forge will not be a guideline or a checklist but a 'go to' website for research on randomised trials methods, with a linked programme of applied methodology research, coupled to an effective evidence-dissemination process. Moreover, it will support an informal network of interested trialists who meet virtually (online) and occasionally in person to build capacity and knowledge in the design and conduct of efficient randomised trials.Some of the resources invested in randomised trials are wasted because of limited evidence upon which to base many aspects of design, conduct, analysis, and reporting of clinical trials. Trial Forge will help to address this lack of evidence.

  2. Characterization of residual stresses in heat treated Ti-6Al-4V forgings by machining induced distortion

    NASA Astrophysics Data System (ADS)

    Regener, B.; Krempaszky, C.; Werner, E.

    2010-06-01

    To provide a solid base for improved material exploitation in dimensioning calculations it is necessary to determine the stress state in the part prior to service loading. In order to achieve higher material strength at elevated temperatures, the surface temperature gradient with respect to time has to be sufficiently high during heat treatment. This results in non-negligable residual stresses that can reduce the allowable load level upon which yielding occurs. For titanium alloys there are two common heat treatments, namely solution treatment and mill annealing. The latter one is the method of choice within the presented project. Mill annealing is utilized in order to significantly reduce the residual stresses in the parts without loosing much of the improved strength at elevated temperatures. Quantification of residual stresses is done by solving an inverse problem. From the measurement of distortion, induced by dividing the investigated part, the residual stress state can be calculated via analytical modeling or correlation with finite element models. To assure a minimum perturbation of the residual stress state during specimen production, dividing of the part is accomplished by electric discharge machining. The parts of interest are v-shaped prisms with a length of approximatly 450 mm and a thickness in the cross sectional area from about 20 mm to 45 mm. Figure 1(a) shows the forged part and 1(b) the dimensions of the cross section in millimeters as well as the material properties considered in the finite element model. The heat exchange between the part and the environment is modelled as heat transfer by convection superimposed with heat radiation. Since the parts are exposed to air during forging and heat treatment, the surface develops a strongly adhesive oxide layer, the so called alpha-case. After forging the parts are cooled in air and heat treated at a temperature of 720° C for a duration of 120 min. Subsequent air cooling and removing the alpha-case by

  3. Development of a dynamic recrystallization model for a β-solidifying titanium aluminide alloy using Kocks-Mecking plots

    NASA Astrophysics Data System (ADS)

    Bambach, Markus; Sizova, Irina; Bolz, Sebastian; Weiß, Sabine

    2016-10-01

    Intermetallic titanium aluminide alloys are of growing interest for aerospace and automotive industries due to their remarkable mechanical properties at elevated temperature. The present study focusses on the investigation of the high-temperature deformation behavior of an intermetallic alloy with the nominal composition Ti-44.5Al-6.25Nb-0.8Mo-0.1B. Isothermal compression tests were conducted on a Gleeble 3500 simulator. The flow curves were transformed into Kocks-Mecking plots, where remarkable features such as the absence of stage-III hardening and an inflection point marking the onset of dynamic recrystallization were observed. Based on these observations, a phenomenological flow stress model was devised which incorporates the observations revealed through the Kocks-Mecking plots and reproduces the course of flow stress up to the peak stress and towards the steady-state well. The model may hence be used in finite element simulations of isothermal forging of titanium aluminides.

  4. Precision Cleaning Titanium Components

    SciTech Connect

    Hand, T.E.; Bohnert, G.W.

    2000-02-02

    Clean bond surfaces are critical to the operation of diffusion bonded titanium engine components. These components can be contaminated with machining coolant, shop dirt, and fingerprints during normal processing and handling. These contaminants must be removed to achieve acceptable bond quality. As environmental concerns become more important in manufacturing, elimination of the use of hazardous materials is desired. For this reason, another process (not using nitric-hydrofluoric acid solution) to clean titanium parts before bonding was sought. Initial cleaning trials were conducted at Honeywell to screen potential cleaning techniques and chemistries. During the initial cleaning process screening phase, Pratt and Whitney provided Honeywell with machined 3 inch x 3 inch x 1 inch titanium test blocks. These test blocks were machined with a water-based machining coolant and exposed to a normal shop environment and handling. (Honeywell sectioned one of these blocks into smaller samples to be used for additional cleanliness verification analyses.) The sample test blocks were ultrasonically cleaned in alkaline solutions and AUGER analysis was used by Honeywell FM and T to validate their cleanliness. This information enabled selection of final cleaning techniques and solutions to be used for the bonding trials. To validate Honeywell's AUGER data and to verify the cleaning processes in actual situations, additional sample blocks were cleaned (using the chosen processes) and then bonded. The bond quality of the test blocks was analyzed according to Pratt and Whitney's requirements. The Charpy impact testing was performed according to ASTM procedure {number_sign}E-23. Bond quality was determined by examining metallographic samples of the bonded test blocks for porosity along the bondline.

  5. Forging New Links in the Asteroid-Meteorite Connection

    NASA Astrophysics Data System (ADS)

    Binzel, R. P.

    1995-09-01

    Historically, the path linking telescopic measurements of asteroids with laboratory measurements of meteorites has been an arduous one full of dead ends and dark passages. However some recent successes are beginning to clear and illuminate the path. Largely these successes have come about through advances in astronomical instrumentation and dedicated surveys of main-belt asteroids down to sizes substantially smaller than what had been previously observed. In addition, the most immediate precursor precursor population to meteorites, the near-Earth asteroids, are becoming more thoroughly studied. Three new links appear to have been forged. The strongest is the previously debated link between Vesta and the HED meteorites [1,2,3]. In a new survey of small (diameter < 20 km) main-belt asteroids, Binzel and Xu [4] found 20 which have visible spectra matching that which was previously unique to Vesta and the HED meteorites. While most appeared dynamically clustered around Vesta, eight of the discovered Vesta-like asteroids bridged the orbital space between Vesta and the 3:1 Jovian resonance -- a dynamical escape hatch to the inner solar system. Thus the observations demonstrate a complete delivery route for fragments from Vesta to the Earth, implying strong confidence that HED meteorites are derived from Vesta. The broad implications are that Vesta is now the fourth planetary body for which we have known samples, thus opening a new field for meteoritics and planetary science -- the geology of Vesta. A second, but more tentative link, is the discovery [5] of at least one small main-belt asteroid, 3628 Boznemcova, whose spectrum resembles ordinary chondrite meteorites. Previously, only one Earth-crossing asteroid (1862 Apollo) appeared to provide an asteroid spectral analog to these most common meteorites. Unfortunately the discovery of just one small main-belt ordinary chondrite-like asteroid out of about 1000 surveyed does not resolve issues such as whether space

  6. Polyisocyanides of titanium.

    PubMed

    Rayón, Víctor M; Redondo, Pilar; Valdés, Haydee; Barrientos, Carmen; Largo, Antonio

    2009-02-26

    Neutral Ti[CN](n) complexes have been investigated with quantum chemistry techniques. According to our theoretical predictions, these complexes are shown to prefer isocyanide arrangements. Therefore, these compounds are good candidates to be the first polyisocyanides to be characterized. The theoretical calculations predict Ti(NC)(4), a methane-like tetrahedral structure with four isocyanide ligands, as the most stable neutral complex. The fact that the isocyanide ligand is a better pi-donor than the cyanide one seems to be the key factor for the preference for isocyanides in neutral titanium complexes.

  7. Effect of Die Strength and Work Piece Strength on the Wear of Hot Forging Dies

    NASA Astrophysics Data System (ADS)

    Levy, B. S.; Van Tyne, C. J.

    2015-01-01

    The effect of the strength ratio extracted from an Archard model for wear is used to describe the wear rates expected in hot forging dies. In the current study, the strength ratio is the strength of the hot forging die to the strength of the work piece. Three hot forging die steels are evaluated. The three die steels are FX, 2714, and WF. To determine the strength of the forging die, a continuous function has been developed that describes the yield strength of three die steels for temperatures from 600 to 700 °C and for times up to 20 h (i.e., tempering times of up to 20 h). The work piece material is assumed to be AISI 1045. Based on the analysis, the wear resistance of WF should be superior and FX should be slightly better than 2714. Decreasing the forging temperature increases the strength ratio, because the strength of the die surface increases faster than the flow strength of AISI 1045. The increase in the strength ratio indicates a decrease in the expected wear rate.

  8. Identification of forged Bank of England £20 banknotes using IR spectroscopy.

    PubMed

    Sonnex, Emily; Almond, Matthew J; Baum, John V; Bond, John W

    2014-01-24

    Bank of England notes of £20 denomination have been studied using infrared spectroscopy in order to generate a method to identify forged notes. An aim of this work was to develop a non-destructive method so that a small, compact Fourier transform infrared spectrometer (FT-IR) instrument could be used by bank workers, police departments or others such as shop assistants to identify forged notes in a non-lab setting. The ease of use of the instrument is the key to this method, as well as the relatively low cost. The presence of a peak at 1400 cm(-1) arising from νasym (CO3(2-)) from the blank paper section of a forged note proved to be a successful indicator of the note's illegality for the notes that we studied. Moreover, differences between the spectra of forged and genuine £20 notes were observed in the ν(OH) (ca. 3500 cm(-1)), ν(C-H) (ca. 2900 cm(-1)) and ν(C=O) (ca. 1750 cm(-1)) regions of the IR spectrum recorded for the polymer film covering the holographic strip. In cases where these simple tests fail, we have shown how an infrared microscope can be used to further differentiate genuine and forged banknotes by producing infrared maps of selected areas of the note contrasting inks with background paper.

  9. Test report: effect of specimen orientation and location on the tensile properties of GTS forging 1472859

    SciTech Connect

    Melcher, Ryan J

    2008-02-12

    ASTM standardized tensile tests were performed on GTS WR-quality 1472859 forging (21-6- 9 material) to determine the dependence of tensile properties on specimen orientation (longitudinal vs. transverse) with respect to forging ‘grain flow’ and location within the forging. Statistical analyses of the results show that location has a statistically measurable effect on the longitudinal tensile properties (as compared to the error involved in tensile testing). However, this dependence of the properties with location, especially in the circumferential orientation, causes large variability in the results that clouds the statistical determination of any orientation effect. As a result, this forging is determined to be inhomogeneous along the forging length, with a significant range in properties observed (e.g. yield strengths from 85 to 117 ksi) and highest strength/lowest ductility in the spherical region. Additional specimens should be tested to acquire a higher resolution view of this inhomogeneity if the end use of the data is structural integrity analyses using spatially dependent properties; however, sufficient data is provided in this study to extract a statistical lower bound for conservative, homogeneous structural analysis.

  10. Non-isothermal FEM analyses of large-strain back extrusion forging

    SciTech Connect

    Flower, E.C.; Hallquist, J.O.; Shapiro, A.B.

    1986-06-19

    Back extrusion forging is a complex metal forming operation dominated by large-strain, non-isothermal deformation. NIKE2D, a fully vectorized implicit finite-element program developed at Lawrence Livermore National Laboratory, was applied to a two-stage isothermal back extrusion forging process. Modeling of the forging process required special features in the FEM code such as friction and interactive rezoning that allows for remeshing of the distorted mesh while maintaining a complete history of all the state variables. To model conditions of the non-isothermal forging process required implementing TOPAZ2D, our LLNL-developed two-dimensional implicit finite element code for heat conduction analysis, as a subroutine into NIKE2D. The fully coupled version maintains all the original features of both codes and can account for the contribution of heat generation during plastic deformation. NIKE/TOPAZ-2D was applied to the piercing operation of the back extrusion forging process. The thermal deformation history of the die, punch, and workpiece and the effective plastic strains were calculated.

  11. Controlled Forging of a Nb Containing Microalloyed Steel for Automotive Applications

    NASA Astrophysics Data System (ADS)

    Nakhaie, Davood; Hosseini Benhangi, Pooya; Fazeli, Fateh; Mazinani, Mohammad; Zohourvahid Karimi, Ebrahim; Ghandehari Ferdowsi, Mahmoud Reza

    2012-12-01

    Controlled forging of microalloyed steels is a viable economical process for the manufacture of automotive parts. Ferrite grain refinement and precipitation hardening are the major microstructural parameters to enhance the mechanical properties of the forged components. In the current study, a modified thermomechanical treatment for additional ferrite grain refinement is developed by exploiting the effect of Nb in increasing the T NR (no recrystallization temperature) and via phase transformation from a pancaked austenite. This is accomplished by performing the final passes of forging below the T NR temperature followed by a controlled cooling stage to produce a mixture of fine grained ferrite, small scaled acicular ferrite as well as a limited amount of martensite. The effect of processing parameters in terms of forging strain, cooling rate and aging condition on the microstructure and mechanical properties of a medium carbon, Nb containing microalloyed steel is investigated. An attempt is made to identify a suitable microstructure that provides a proper combination of high strength and good impact toughness. The processing-microstructure relationships for the proposed novel forging procedure are discussed, and directions for further improvements are outlined.

  12. Identification of Forged Bank of England 20 Gbp Banknotes Using IR Spectroscopy

    NASA Astrophysics Data System (ADS)

    Sonnex, Emily

    2014-06-01

    Bank of England notes of 20 GBP denomination have been studied using infrared spectroscopy in order to generate a method to identify forged notes. A principal aim of this work was to develop a method so that a small, compact ATR FTIR instrument could be used by bank workers, police departments or others such as shop assistants to identify forged notes in a non-lab setting. The ease of use of the instrument is the key to this method, as well as the relatively low cost. The presence of a peak at 1400 wn from the blank paper section of a forged note proved to be a successful indicator of the note's illegality for the notes that we studied. Moreover, differences between the spectra of forged and genuine 20 GBP notes were observed in the ν(OH) (ca. 3500 wn), ν(C-H) (ca. 2900 wn) and ν(C=O) (ca. 1750 wn) regions of the IR spectrum recorded for the polymer film covering the holographic strip. In cases where these simple tests fail, we have shown how an infrared microscope can be used to further differentiate genuine and forged banknotes by producing infrared maps of selected areas of the note contrasting inks with background paper. Further to this, with an announcement by the Bank of England to produce polymer banknotes in the future, the work has been extended using Australian polymer banknotes to show that the method would be transferable.

  13. Forging of Naval Brass (ASTM B16) - Finite Element Analysis using Ls Dyna

    NASA Astrophysics Data System (ADS)

    Subha Sankari, T.; Sangavi, S.; Paneerselvam, T.; Venkatraman, R.; Venkatesan, M.

    2016-09-01

    Forging is one of the important manufacturing process in which products like connecting rod, transmission shaft, clutch hubs and gears are produced. Finite element analysis (FEA) in forming techniques is of recent interest for the optimal design and determination of right manufacturing forming process. The data from the numerical results can help in providing the information for selecting the ideal process conditions. Thus aside from experimental values, simulation by the finite element analysis software's such as LS DYNA can be used for the analysis of strain distribution in forging processes. In the present work, Finite element simulation of open die forging of naval brass (ASTM B16) is done at an optimal temperature. An advanced multi physics simulation software package by the Livermore software technology cooperation LSTC - LS DYNA is utilized for the simulation of forging process. For the forging validation, experiment is conducted with a cylindrical billet having height 45 mm and diameter of 40mm. The numerical results are compared with that of experimental results carried out at the same temperature and dimensions for validation. The distribution of strain is analyzed. Energy analysis due to impact load is detailed. The simulation results are found to be in good agreement with the experimental results.

  14. TDNiCr (ni-20Cr-2ThO2) forging studies

    NASA Technical Reports Server (NTRS)

    Filippi, A. M.

    1974-01-01

    Elevated temperature tensile and stress rupture properties were evaluated for forged TDNiCr (Ni-20Cr-2ThO2) and related to thermomechanical history and microstructure. Forging temperature and final annealed condition had pronounced influences on grain size which, in turn, was related to high temperature strength. Tensile strength improved by a factor of 8 as grain size changed from 1 to 150 microns. Stress-rupture strength was improved by a factor of 3 to 5 by a grain size increase from 10 to 1000 microns. Some contributions to the elevated temperature strength of very large grain material may also occur from the development of a strong texture and a preponderance of small twins. Other conditions promoting the improvement of high temperature strength were: an increase of total reduction, forging which continued the metal deformation inherent in the starting material, a low forging speed, and prior deformation by extrusion. The mechanical properties of optimally forged TDNiCr compared favorably to those of high strength sheet developed for space shuttle application.

  15. Process for stabilization of titanium silicide particulates within titanium aluminide containing metal matrix composites

    SciTech Connect

    Christodoulou, L.; Williams, J.C.; Riley, M.A.

    1990-04-10

    This paper describes a method for forming a final composite material comprising titanium silicide particles within a titanium aluminide containing matrix. It comprises: contacting titanium, silicon and aluminum at a temperature sufficient to initiate a reaction between the titanium and silicon to thereby form a first composite comprising titanium silicide particles dispersed within an aluminum matrix; admixing the first composite with titanium and zirconium to form a mixture; heating the mixture to a temperature sufficient to convert at least a portion of the aluminum matrix to titanium aluminide; and recovering a final composite material comprising titanium silicide particles dispersed within a titanium aluminide containing matrix.

  16. Electrorotation of titanium microspheres.

    PubMed

    Arcenegui, Juan J; Ramos, Antonio; García-Sánchez, Pablo; Morgan, Hywel

    2013-04-01

    Electrorotation (ROT) data for solid titanium micrometer-sized spheres in an electrolyte are presented for three different ionic conductivities, over the frequency range of 10 Hz to 100 kHz. The direction of rotation was found to be opposite to the direction of rotation of the electric field vector (counterfield electrorotation), with a single rotation peak. The maximum rotation rate occurs at a frequency of the order of the reciprocal RC time constant for charging the particle double layer capacitance through the resistor of the electrolyte bulk. A model for the electrical torque acting on a metallic sphere is presented, using a constant phase element impedance to describe the metal/electrolyte interface. The titanium spheres are much denser than the electrolyte and rest on the bottom substrate. Therefore, the electrical and viscous torques near a wall are considered in the analysis. Good agreement is found between the predicted and measured rotational speed as a function of frequency. Theory shows that there is no effect of induced charge electroosmotic flow on the ROT, as observed experimentally.

  17. Compaction of Titanium Powders

    SciTech Connect

    Gerdemann, Stephen,J; Jablonski, Paul, J

    2011-05-01

    Accurate modeling of powder densification has been an area of active research for more than 60 years. The earliest efforts were focused on linearization of the data because computers were not readily available to assist with curve-fitting methods. In this work, eight different titanium powders (three different sizes of sponge fines<150 {micro}m,<75 {micro}m, and<45 {micro}m; two different sizes of a hydride-dehydride [HDH]<75 {micro}m and<45 {micro}m; an atomized powder; a commercially pure [CP] Ti powder from International Titanium Powder [ITP]; and a Ti 6 4 alloy powder) were cold pressed in a single-acting die instrumented to collect stress and deformation data during compaction. From these data, the density of each compact was calculated and then plotted as a function of pressure. The results show that densification of all the powders, regardless of particle size, shape, or chemistry, can be modeled accurately as the sum of an initial density plus the sum of a rearrangement term and a work-hardening term. These last two terms are found to be a function of applied pressure and take the form of an exponential rise.

  18. Compaction of Titanium Powders

    SciTech Connect

    Stephen J. Gerdemann; Paul D. Jablonski

    2010-11-01

    Accurate modeling of powder densification has been an area of active research for more than 60 years. The earliest efforts were focused on linearization of the data because computers were not readily available to assist with curve-fitting methods. In this work, eight different titanium powders (three different sizes of sponge fines <150 μm, <75 μm, and < 45 μm; two different sizes of a hydride-dehydride [HDH] <75 μm and < 45 μm; an atomized powder; a commercially pure [CP] Ti powder from International Titanium Powder [ITP]; and a Ti 6 4 alloy powder) were cold pressed in a single-acting die instrumented to collect stress and deformation data during compaction. From these data, the density of each compact was calculated and then plotted as a function of pressure. The results show that densification of all the powders, regardless of particle size, shape, or chemistry, can be modeled accurately as the sum of an initial density plus the sum of a rearrangement term and a work-hardening term. These last two terms are found to be a function of applied pressure and take the form of an exponential rise.

  19. Development of forging and heat treating practices for AMS 5737 for use at liquid helium temperatures

    SciTech Connect

    Dalder, E.N.C.; Greenlee, M.

    1981-08-10

    To achieve a combination of high yield-strength (sigma y), plane-strain fracture-toughness (K/sub IC/) and resistance to galling when turned against austenitic stainless steels in highly-loaded threaded turnbuckles in the M.F.T.F.-B (Mirror Fusion Test Facility), AMS 5737 (Fe-15Cr-25Ni-1Mo-V-Ti-Al-B), a heat-treatable Fe-base superalloy that is slightly-ferromagnetic under high magnetic fields at 4K, was chosen for large (approx. 340 kg) forged turn buckles. This report describes the forging and heat-treatment optimization program that resulted in good sigma y and K/sub IC/ over the 4 to 300K range of service-temperatures and the verification tests run on a pre-production forging and actual production parts.

  20. Ultrasonic attenuation measurements in sinter-forged YBa2Cu3O7-δ

    NASA Astrophysics Data System (ADS)

    Xu, M.-F.; Bein, D.; Wiegert, R. F.; Sarma, Bimal K.; Levy, M.; Zhao, Z.; Adenwalla, S.; Moreau, A.; Robinson, Q.; Johnson, D. L.; Hwu, S. J.; Poeppelmeier, K. R.; Ketterson, J. B.

    1989-01-01

    We report ultrasonic attenuation measurements on sinter-forged YBa2Cu2O7-δ material, which differs from ordinary sintered material in that the crystallites are preferentially oriented to form a uniaxial sample. Three peaks in attenuation, at temperatures of 250, 180, and 70 K, were observed for longitudinal waves propagating perpendicular to the forging axis, which is similar to that reported in ordinary (isotropic) polycrystalline samples. However, for both transverse and longitudinal sound propagated along the forging axis we have a different behavior, with only one peak at 180 K, showing a strong anisotropy. It is suggested that sound waves traveling parallel to and normal to the Cu-O planes may account for the anisotropic effect, and a relaxation mechanism may explain the increase in shear wave attenuation which was seen with decreasing temperature.

  1. Analysis Of Potentiometric Methods Used For Crack Detection In Forging Tools

    NASA Astrophysics Data System (ADS)

    Pilc, Jozef; Drbúl, Mário; Stančeková, Dana; Varga, Daniel; Martinček, Juraj; Kuždák, Viktor

    2015-12-01

    Increased use of forging tools in mass production causes their increased wear and creates pressure to design more efficient renovation process. Renovation is complicated because of the identification of cracks expanding from the surface to the core material. Given that the production of forging tools is expensive, caused by the cost of tool steels and the thermo-chemical treatment, it is important to design forging tool with its easy renovation in mind. It is important to choose the right renovation technology, which will be able to restore the instrument to its original state while maintaining financial rentability. Choosing the right technology is difficult because of nitrided and heat-treated surface for high hardness and wear resistance. Article discusses the use of non-destructive method of detecting cracks taking into account the size of the cracks formed during working process.

  2. Evaluation of Die Chilling Effects during Forging of Nimonic-80A Superalloy

    SciTech Connect

    Shahriari, D.; Sadeghi, M. H.; Amiri, A.; Cheraghzadeh, M.

    2010-06-15

    Nimonic-80A is a kind of nickel-based superalloys which is used in high temperature components of land gas turbines. In this paper, the influence of four design factors: die temperature, strain rate, friction coefficient and geometry size of ring sample over the variation of internal diameters (VID) and forging load (FL) was studied. It was done by means of design methodology based on DOE-designated full factorial and FE simulations. FEM and experimental results showed that the variation of internal diameters and forging load had inverse proportion to the die temperature. Regression models were developed by using the response surface methodology (RSM) for VID and FL. Rate of the dynamic recrystallization varied depending on different amounts of die temperature. The results can be used in the semi-isothermal forging of complex part of the Nimonic-80A.

  3. Queen City Forging Revitalized by Oak Ridge National Lab Partnership – U.S. Department of Energy

    SciTech Connect

    Mayer, Rob; Blue, Craig

    2016-05-11

    Oak Ridge National Laboratory, with support from the U.S. Department of Energy, teamed up with Queen City Forging, the U.S. Forging Industry, and Infrared Heating Technologies to develop a rapid-infrared heating furnace to produce aluminum turbochargers.

  4. Queen City Forging Revitalized by Oak Ridge National Lab Partnership – U.S. Department of Energy

    ScienceCinema

    Mayer, Rob; Blue, Craig

    2016-07-12

    Oak Ridge National Laboratory, with support from the U.S. Department of Energy, teamed up with Queen City Forging, the U.S. Forging Industry, and Infrared Heating Technologies to develop a rapid-infrared heating furnace to produce aluminum turbochargers.

  5. Multi-objective optimization of gear forging process based on adaptive surrogate meta-models

    NASA Astrophysics Data System (ADS)

    Meng, Fanjuan; Labergere, Carl; Lafon, Pascal; Daniel, Laurent

    2013-05-01

    In forging industry, net shape or near net shape forging of gears has been the subject of considerable research effort in the last few decades. So in this paper, a multi-objective optimization methodology of net shape gear forging process design has been discussed. The study is mainly done in four parts: building parametric CAD geometry model, simulating the forging process, fitting surrogate meta-models and optimizing the process by using an advanced algorithm. In order to maximally appropriate meta-models of the real response, an adaptive meta-model based design strategy has been applied. This is a continuous process: first, bui Id a preliminary version of the meta-models after the initial simulated calculations; second, improve the accuracy and update the meta-models by adding some new representative samplings. By using this iterative strategy, the number of the initial sample points for real numerical simulations is greatly decreased and the time for the forged gear design is significantly shortened. Finally, an optimal design for an industrial application of a 27-teeth gear forging process was introduced, which includes three optimization variables and two objective functions. A 3D FE nu merical simulation model is used to realize the process and an advanced thermo-elasto-visco-plastic constitutive equation is considered to represent the material behavior. The meta-model applied for this example is kriging and the optimization algorithm is NSGA-II. At last, a relatively better Pareto optimal front (POF) is gotten with gradually improving the obtained surrogate meta-models.

  6. Cementless surface replacement hemiarthroplasty for primary glenohumeral osteoarthritis: results of over 5-year follow-up in patients with or without rotator cuff deficiency

    PubMed Central

    Al-Hadithy, Nawfal; Furness, Nicholas; Patel, Ronak; Jonas, Sam; Jobbagy, Attila; Lowdon, Ian

    2015-01-01

    Background Cementless surface replacement hemiarthroplasty (CSRHA) is an established treatment for glenohumeral osteoarthritis; however, studies evaluating its role in arthritis with rotator cuff deficiency are limited. This study reviews the outcomes of CSRHA for glenohumeral osteoarthritis with and without rotator cuff tears. Methods 41 CSRHA (Mark III Copeland prosthesis) were performed for glenohumeral osteoarthritis with intact rotator cuffs (n = 21) and cuff-deficient shoulders (n = 20). Patients were assessed using Oxford and Constant questionnaires, patient satisfaction, range of motion measurements and by radiography. Results Mean age and follow-up were 75 years and 5.1 years, respectively. Functional gains were significantly higher in patients with intact rotator cuffs compared to cuff-deficient shoulders, with Oxford Shoulder Score improving from 18 to 37.5 and 15 to 27 and forward flexion improved from 60° to 126° and 44° to 77° in each group, respectively. Two patients with deficient cuffs had deficient subscapularis tendons; one of which was dislocated anteriorly. Conclusions CSRHA provides significant improvements in pain and function in patients with glenohumeral osteoarthritis. In patients with deficient cuffs, functional gains are limited, and should be considered in low-demand patients where pain is the primary problem. Caution should be taken in patients with a deficient subscapularis as a result of the risk of dislocation. PMID:27582984

  7. Computer modeling of wear in extrusion and forging of automotive exhaust valves

    NASA Astrophysics Data System (ADS)

    Tulsyan, R.; Shivpuri, R.

    1995-04-01

    In an automotive engine valve forging process, the billet is cold sheared, induction heated, and fed to a mechanical press for a two-stage forging operation with the first stage being extrusion. The main limiting factor in this operation is the wear of the dies during the first stage, extrusion. In this study. abrasive wear was identified as the primary mode of wear, and computer simulation was used to investigate the effect of process variables, such as press speed, initial billet temperature, and die preheat temperature upon abrasive wear. The result generated by this study should be applicable to other part geometry and not limited just to exhaust valves.

  8. The Development of a Ceramic Mold for Hot-Forging of Micro-Magnets

    SciTech Connect

    Christenson, Todd; Garino, Terry

    1999-06-25

    A new mold material has been developed for use in making rare-earth permanent magnet components with precise dimensions in the 10 to 1000 µm range by hot-forging. These molds are made from molds poly(methyl)methacrylate (PMMA) made by deep x-ray lithography (DXRL). An alumina bonded with colloidal silica has been developed for use in these molds. This material can be heated to 950°C without changing dimensions where it develops the strength needed to withstand the hot-fmging conditions (750°C, 100 MPa). In addition, it disintegrates in HF so that parts can be easily removed after forging.

  9. Diffusion bonding of titanium-titanium aluminide-alumina sandwich

    SciTech Connect

    Wickman, H.A.; Chin, E.S.C.; Biederman, R.R.

    1995-12-31

    Diffusion bonding of a metallic-intermetallic-ceramic sandwich is of interest for potential armor applications. Low cost titanium, titanium diboride reinforced titanium aluminide (Ti-48at.%Al), and aluminum oxide are diffusion bonded in a vacuum furnace between 1,000 C and 1,400 C. Metallographic examination of the prior bonding interface showed excellent metallurgical coupling between the Ti-48at.%Al composite and the low cost Ti. A series of microstructures representative of phases consistent with a hypothetical Ti-Al-B phase diagram is visible. The alumina-Ti-48at.%Al interfacial bond is achieved through penetration of titanium-aluminum phases into the existing alumina porosity. A detailed microstructural analysis identifying mechanisms of interfacial bonding will be presented for each interfacial zone.

  10. Beta titanium alloys and their role in the titanium industry

    NASA Astrophysics Data System (ADS)

    Bania, Paul J.

    1994-07-01

    The class of titanium alloys generically referred to as the beta alloys is arguably the most versatile in the titanium family. Since these alloys offer the highest strength-to-weight ratios and deepest hardenability of all titanium alloys, one might expect them to compete favorably for a variety of aerospace applications. To the contrary, however, except for one very successful application (Ti-13V-11Cr-3Al on the SR-71), the beta alloys have remained a very small segment of the industry. As a perspective on this situation, this article reviews some past and present applications of titanium alloys. It also descibes some unique new alloys and applications that promise to reverse historical trends.

  11. Gamma titanium aluminide alloys

    SciTech Connect

    Yamaguchi, M.; Inui, H.; Kishida, K.; Matsumuro, M.; Shirai, Y.

    1995-08-01

    Extensive progress and improvements have been made in the science and technology of gamma titanium aluminide alloys within the last decade. In particular, the understanding of their microstructural characteristics and property/microstructure relationships has been substantially deepened. Based on these achievements, various engineering two-phase gamma alloys have been developed and their mechanical and chemical properties have been assessed. Aircraft and automotive industries arc pursuing their introduction for various structural components. At the same time, recent basic studies on the mechanical properties of two-phase gamma alloys, in particular with a controlled lamellar structure have provided a considerable amount of fundamental information on the deformation and fracture mechanisms of the two-phase gamma alloys. The results of such basic studies are incorporated in the recent alloy and microstructure design of two-phase gamma alloys. In this paper, such recent advances in the research and development of the two-phase gamma alloys and industrial involvement are summarized.

  12. Advanced titanium processing

    SciTech Connect

    Hartman, Alan D.; Gerdemann, Stephen J.; Schrems, Karol K.; Holcomb, Gordon R.; Argetsinger, Edward R.; Hansen, Jeffrey S.; Paige, Jack I.; Turner, Paul C.

    2001-01-01

    The Albany Research Center of the U.S. Department of Energy has been investigating a means to form useful wrought products by direct and continuous casting of titanium bars using cold-wall induction melting rather than current batch practices such as vacuum arc remelting. Continuous ingots produced by cold-wall induction melting, utilizing a bottomless water-cooled copper crucible, without slag (CaF2) additions had minor defects in the surface such as ''hot tears''. Slag additions as low as 0.5 weight percent were used to improve the surface finish. Therefore, a slag melted experimental Ti-6Al-4V alloy ingot was compared to a commercial Ti-6Al-4V alloy ingot in the areas of physical, chemical, mechanical, and corrosion attributes to address the question, ''Are any detrimental effects caused by slag addition''?

  13. Hemocompatibility of titanium nitride.

    PubMed

    Dion, I; Baquey, C; Candelon, B; Monties, J R

    1992-10-01

    The left ventricular assist device is based on the principle of the Maillard-Wenkel rotative pump. The materials which make up the pump must present particular mechanical, tribological, thermal and chemical properties. Titanium nitride (TiN) because of its surface properties and graphite because of its bulk characteristics have been chosen. The present study evaluated the in vitro hemocompatibility of TiN coating deposited by the chemical vapor deposition process. Protein adsorption, platelet retention and hemolysis tests have been carried out. In spite of some disparities, the TiN behavior towards albumin and fibrinogen is interesting, compared with the one of a reference medical grade elastomer. The platelet retention test gives similar results as those achieved with the same elastomer. The hemolysis percentage is near to zero. TiN shows interesting characteristics, as far as mechanical and tribological problems are concerned, and presents very encouraging blood tolerability properties.

  14. Hydrogen in titanium alloys

    SciTech Connect

    Wille, G W; Davis, J W

    1981-04-01

    The titanium alloys that offer properties worthy of consideration for fusion reactors are Ti-6Al-4V, Ti-6Al-2Sn-4Zr-2Mo-Si (Ti-6242S) and Ti-5Al-6Sn-2Zr-1Mo-Si (Ti-5621S). The Ti-6242S and Ti-5621S are being considered because of their high creep resistance at elevated temperatures of 500/sup 0/C. Also, irradiation tests on these alloys have shown irradiation creep properties comparable to 20% cold worked 316 stainless steel. These alloys would be susceptible to slow strain rate embrittlement if sufficient hydrogen concentrations are obtained. Concentrations greater than 250 to 500 wppm hydrogen and temperatures lower than 100 to 150/sup 0/C are approximate threshold conditions for detrimental effects on tensile properties. Indications are that at the elevated temperature - low hydrogen pressure conditions of the reactors, there would be negligible hydrogen embrittlement.

  15. A "clickable" titanium surface platform.

    PubMed

    Watson, Matthew A; Lyskawa, Joël; Zobrist, Cédric; Fournier, David; Jimenez, Maude; Traisnel, Michel; Gengembre, Léon; Woisel, Patrice

    2010-10-19

    A straightforward functionalization of a titanium surface using "click" chemistry is reported. A "clickable" titanium surface platform was prepared by the immobilization of an azide-functionalized electroactive catechol anchor and was subsequently derivatized with an electroactive or fluorinated probe via the CuAAC (copper-catalyzed azide-alkyne cycloaddition) reaction. The course of the reaction was investigated by contact angle, XPS, and electrochemical measurements.

  16. Low cost titanium--myth or reality

    SciTech Connect

    Turner, Paul C.; Hartman, Alan D.; Hansen, Jeffrey S.; Gerdemann, Stephen J.

    2001-01-01

    In 1998, approximately 57,000 tons of titanium metal was consumed in the form of mill products (1). Only about 5% of the 4 million tons of titanium minerals consumed each year is used to produce titanium metal, with the remainder primarily used to produce titanium dioxide pigment. Titanium metal production is primarily based on the direct chlorination of rutile to produce titanium tetrachloride, which is then reduced to metal using the Kroll magnesium reduction process. The use of titanium is tied to its high strength-to-weight ratio and corrosion resistance. Aerospace is the largest application for titanium, and titanium cost has prevented its use in non-aerospace applications including the automotive and heavy vehicle industries.

  17. Characterization of Cracking and Crack Growth Properties of the C5A Aircraft Tie-Box Forging

    NASA Technical Reports Server (NTRS)

    Piascik, Robert S.; Smith, Stephen W.; Newman, John A.; Willard, Scott A.

    2003-01-01

    Detailed destructive examinations were conducted to characterize the integrity and material properties of two aluminum alloy (7075-T6) horizontal stabilizer tie box forgings removed.from US. Air Force C5A and C5B transport aircraft. The C5B tie box forging was,found to contain no evidence of cracking. Thirteen cracks were found in the CSA,forging. All but one of the cracks observed in the C5A component were located along the top cap region (one crack was located in the bottom cap region). The cracks in the C5A component initiated at fastener holes and propagated along a highly tunneled intergranular crack path. The tunneled crack growth configuration is a likelv result of surface compressive stress produced during peening of the .forging suijace. The tie box forging ,fatigue crack growth, fracture and stress corrosion cracking (SCC) properties were characterized. Reported herein are the results of laboratory air ,fatigue crack growth tests and 95% relative humidity SCC tests conducted using specimens machined from the C5A ,forging. SCC test results revealed that the C5A ,forging material was susceptible to intergranular environmental assisted cracking: the C5A forging material exhibited a SCC crack-tip stress-intensity factor threshold of less than 6 MPadn. Fracture toughness tests revealed that the C5A forging material exhibited a fracture toughness that was 25% less than the C5B forging. The C5A forging exhibited rapid laboratory air fatigue crack growth rates having a threshold crack-tip stress-intensity factor range of less than 0.8 MPa sup m. Detailed fractographic examinations revealed that the ,fatigue crack intergranular growth crack path was similar to the cracking observed in the C5A tie box forging. Because both fatigue crack propagation and SCC exhibit similar intergranular crack path behavior, the damage mechanism resulting in multi-site cracking of tie box forgings cannot be determined unless local cyclic stresses can be quantified.

  18. TC17 titanium alloy laser melting deposition repair process and properties

    NASA Astrophysics Data System (ADS)

    Liu, Qi; Wang, Yudai; Zheng, Hang; Tang, Kang; Li, Huaixue; Gong, Shuili

    2016-08-01

    Due to the high manufacturing cost of titanium compressor blisks, aero engine repairing process research has important engineering significance and economic value. TC17 titanium alloy is a rich β stable element dual α+β phase alloy whose nominal composition is Ti-5Al-2Sn-2Zr-4Mo-4Cr. It has high mechanical strength, good fracture toughness, high hardenability and a wide forging-temperature range. Through a surface response experiment with different laser powers, scanning speeds and powder feeding speeds, the coaxial powder feeding laser melting deposition repair process is studied for the surface circular groove defects. In this paper, the tensile properties, relative density, microhardness, elemental composition, internal defects and microstructure of the laser-repaired TC17 forging plate are analyzed. The results show that the laser melting deposition process could realize the form restoration of groove defect; tensile strength and elongation could reach 1100 MPa and 10%, which could reach 91-98% that of original TC17 wrought material; with the optimal parameters (1000 W-25 V-8 mm/s), the microhardness of the additive zone, the heat-affected zone and base material is evenly distributed at 370-390 HV500. The element content difference between the additive zone and base material is less than ±0.15%. Due to the existence of the pores 10 μm in diameter, the relative density could reach 99%, which is mainly inversely proportional to the powder feeding speed. The repaired zone is typically columnar and dendrite crystal, and the 0.5-1.5 mm-deep heat-affected zone in the groove interface is coarse equiaxial crystal.

  19. Social Work and Engineering Collaboration: Forging Innovative Global Community Development Education

    ERIC Educational Resources Information Center

    Gilbert, Dorie J.

    2014-01-01

    Interdisciplinary programs in schools of social work are growing in scope and number. This article reports on collaboration between a school of social work and a school of engineering, which is forging a new area of interdisciplinary education. The program engages social work students working alongside engineering students in a team approach to…

  20. Jernberg Industries, Inc: Forging Facility Uses Plant-Wide Assessment to Aid Conversion to Lean Manufacturing

    SciTech Connect

    2004-10-01

    Jernberg Industries conducted a plant-wide assessment while converting to lean manufacturing at a forging plant. Seven projects were identified that could yield annual savings of $791,000, 64,000 MMBtu in fuel and 6 million kWh.

  1. Forging the Link between Multicultural Competence and Ethical Counseling Practice: A Historical Perspective

    ERIC Educational Resources Information Center

    Watson, Zarus E. P.; Herlihy, Barbara Richter; Pierce, Latoya Anderson

    2006-01-01

    Recognition of multicultural competence as an essential component of ethical counseling practice is a growing trend. This article presents a historical perspective of salient events that have contributed to forging a link between multicultural competence and ethical behavior. Multicultural counseling is traced from its beginnings to its emergence…

  2. Simulation and Analysis of Finite Volume of Hot Forging Process of Nut

    NASA Astrophysics Data System (ADS)

    Maarefdoust, M.; Hosseyni, M.

    2011-08-01

    In this study the forging operations of nut has been modeled. This nut is a part which is manufactured with the help of hot forging. The aim of this research is utilizing computers in designing forming process, and in particular, modeling of hot forging in the nut and to inquire the stresses appeared on the mold. For this purpose Pro/Engineer software for modeling, and SuperForge2004 software for analyzing the process have been used. This part is formed in two stages. To enrich the results coming out of the use of the software, the findings achieved from the modeling of the first stage are compared with its analytic dissolving. In the second stage modeling of metal forming the effect of rake on increasing the stresses imposed to the die mold is studied. The aim of this research is to correct the molds and the volume of the raw materials so that we can produce high qualified parts in spite of raw material low volume and low pressure on the molds.

  3. Numerical modeling of axi-symmetrical cold forging process by ``Pseudo Inverse Approach''

    NASA Astrophysics Data System (ADS)

    Halouani, A.; Li, Y. M.; Abbes, B.; Guo, Y. Q.

    2011-05-01

    The incremental approach is widely used for the forging process modeling, it gives good strain and stress estimation, but it is time consuming. A fast Inverse Approach (IA) has been developed for the axi-symmetric cold forging modeling [1-2]. This approach exploits maximum the knowledge of the final part's shape and the assumptions of proportional loading and simplified tool actions make the IA simulation very fast. The IA is proved very useful for the tool design and optimization because of its rapidity and good strain estimation. However, the assumptions mentioned above cannot provide good stress estimation because of neglecting the loading history. A new approach called "Pseudo Inverse Approach" (PIA) was proposed by Batoz, Guo et al.. [3] for the sheet forming modeling, which keeps the IA's advantages but gives good stress estimation by taking into consideration the loading history. Our aim is to adapt the PIA for the cold forging modeling in this paper. The main developments in PIA are resumed as follows: A few intermediate configurations are generated for the given tools' positions to consider the deformation history; the strain increment is calculated by the inverse method between the previous and actual configurations. An incremental algorithm of the plastic integration is used in PIA instead of the total constitutive law used in the IA. An example is used to show the effectiveness and limitations of the PIA for the cold forging process modeling.

  4. Tribo-thermal fatigue of the steel used for the forging die construction

    NASA Astrophysics Data System (ADS)

    Drumeanu, A. C.

    2017-02-01

    Frequently the durability of the forging dies is firstly determined by the non-isothermal fatigue wear, which causes the cracks appearance on their internal surfaces, much more before their abrasion wear to reach the limit value. In these conditions it is necessary to design the forging dies firstly by the point of view of the non-isothermal fatigue wear. For a correctly choosing and using of metallic material, it is necessary to determine their intrinsic characteristics regarding its cyclic non-isothermal stresses durability. The experimental determination of these characteristics implies a lot of experiments, which are done in specific conditions, different from those used for isothermal mechanical fatigue durability determination. The paper presents the experimental results concerning intrinsic characteristic determination of the forging dies steel. Based on these results there were determined specific equations which characterize this kind of stresses, and the diagrams that represent their graphic image. These data can be used both in designing and exploitation of the forging dies.

  5. The Ties That Bind: How Social Capital Is Forged and Forfeited in Teacher Communities

    ERIC Educational Resources Information Center

    Bridwell-Mitchell, E. N.; Cooc, North

    2016-01-01

    The effects of social capital on school improvement make it important to understand how teachers forge, maintain, or forfeit collegial relationships. Two common explanations focused on formal organizational features and individual characteristics do not address how social capital accrues from informal dynamics of teachers' interactions in…

  6. T & I--Metalworking, Forging. Kit No. 55. Instructor's Manual [and] Student Learning Activity Guide.

    ERIC Educational Resources Information Center

    Lake, Robert J.

    An instructor's manual and student activity guide on forging are provided in this set of prevocational education materials which focuses on the vocational area of trade and industry (metalworking). (This set of materials is one of ninety-two prevocational education sets arranged around a cluster of seven vocational offerings: agriculture, home…

  7. 76 FR 31585 - Forged Stainless Steel Flanges From India: Notice of Rescission of Antidumping Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-01

    ... International Trade Administration Forged Stainless Steel Flanges From India: Notice of Rescission of... stainless steel flanges from India. The period of review is February 1, 2010, through January 22, 2011... stainless steel flanges from India. See Antidumping or Countervailing Duty Order, Finding, or...

  8. 76 FR 8773 - Forged Stainless Steel Flanges From India and Taiwan

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-15

    ... From the Federal Register Online via the Government Publishing Office INTERNATIONAL TRADE COMMISSION Forged Stainless Steel Flanges From India and Taiwan AGENCY: United States International Trade... steel flanges from India and Taiwan would be likely to lead to continuation or recurrence of...

  9. 76 FR 30200 - Forging Machines; Extension of the Office of Management and Budget's (OMB) Approval of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-24

    ... operated valves and switches. DATES: Comments must be submitted (postmarked, sent, or received) by July 25... clearly and properly identify manually operated valves and switches. Inspection of Forging Machines... Controlled Valves and Switches (paragraphs (c), (h)(3), (i)(1) and (i)(2)). These paragraphs require...

  10. TRITIUM AGING EFFECTS ON THE FRACTURE TOUGHNESS PROPERTIES OF FORGED STAINLESS STEEL

    SciTech Connect

    Morgan, M

    2008-04-14

    The fracture toughness properties of Type 21-6-9 stainless steel were measured for forgings in the unexposed, hydrogen-exposed, and tritium-exposed-and-aged conditions. Fracture toughness samples were cut from conventionally-forged and high-energy-rate-forged forward-extruded cylinders and mechanically tested at room temperature using ASTM fracture-toughness testing procedures. Some of the samples were exposed to either hydrogen or tritium gas (340 MPa, 623 K) prior to testing. Tritium-exposed samples were aged for up to seven years and tested periodically in order to measure the effect on fracture toughness of {sup 3}He from radioactive tritium decay. The results show that hydrogen-exposed and tritium-exposed samples had lower fracture- toughness values than unexposed samples and that fracture toughness decreased with increasing decay {sup 3}He content. Forged steels were more resistant to the embrittling effects of tritium and decay {sup 3}He than annealed steels, although their fracture-toughness properties depended on the degree of sensitization that occurred during processing. The fracture process was dominated by microvoid nucleation, growth and coalescence; however, the size and spacing of microvoids on the fracture surfaces were affected by hydrogen and tritium with the lowest-toughness samples having the smallest microvoids and finest spacing.

  11. A Life Study of Ausforged, Standard Forged and Standard Machined AISI M-50 Spur Gears

    NASA Technical Reports Server (NTRS)

    Townsend, D. P.; Bamberger, E. N.; Zaretsky, E. V.

    1975-01-01

    Tests were conducted at 350 K (170 F) with three groups of 8.9 cm (3.5 in.) pitch diameter spur gears made of vacuum induction melted (VIM) consumable-electrode vacuum-arc melted (VAR), AISI M-50 steel and one group of vacuum-arc remelted (VAR) AISI 9310 steel. The pitting fatigue life of the standard forged and ausforged gears was approximately five times that of the VAR AISI 9310 gears and ten times that of the bending fatigue life of the standard machined VIM-VAR AISI M-50 gears run under identical conditions. There was a slight decrease in the 10-percent life of the ausforged gears from that for the standard forged gears, but the difference is not statistically significant. The standard machined gears failed primarily by gear tooth fracture while the forged and ausforged VIM-VAR AISI M-50 and the VAR AISI 9310 gears failed primarily by surface pitting fatigue. The ausforged gears had a slightly greater tendency to fail by tooth fracture than the standard forged gears.

  12. Interfacial reactions in titanium-matrix composites

    SciTech Connect

    Yang, J.M.; Jeng, S.M. )

    1989-11-01

    A study of the interfacial reaction characteristics of SiC fiber-reinforced titanium aluminide and disordered titanium alloy composites has determined that the matrix alloy compositions affect the microstructure and the distribution of the reaction products, as well as the growth kinetics of the reaction zones. The interfacial reaction products in the ordered titanium aluminide composite are more complicated than those in the disordered titanium-alloy composite. The activation energy of the interfacial reaction in the ordered titanium aluminide composite is also higher than that in the disordered titanium alloy composite. Designing an optimum interface is necessary to enhance the reliability and service life at elevated temperatures. 16 refs.

  13. Cell response of anodized nanotubes on titanium and titanium alloys.

    PubMed

    Minagar, Sepideh; Wang, James; Berndt, Christopher C; Ivanova, Elena P; Wen, Cuie

    2013-09-01

    Titanium and titanium alloy implants that have been demonstrated to be more biocompatible than other metallic implant materials, such as Co-Cr alloys and stainless steels, must also be accepted by bone cells, bonding with and growing on them to prevent loosening. Highly ordered nanoporous arrays of titanium dioxide that form on titanium surface by anodic oxidation are receiving increasing research interest due to their effectiveness in promoting osseointegration. The response of bone cells to implant materials depends on the topography, physicochemistry, mechanics, and electronics of the implant surface and this influences cell behavior, such as adhesion, proliferation, shape, migration, survival, and differentiation; for example the existing anions on the surface of a titanium implant make it negative and this affects the interaction with negative fibronectin (FN). Although optimal nanosize of reproducible titania nanotubes has not been reported due to different protocols used in studies, cell response was more sensitive to titania nanotubes with nanometer diameter and interspace. By annealing, amorphous TiO2 nanotubes change to a crystalline form and become more hydrophilic, resulting in an encouraging effect on cell behavior. The crystalline size and thickness of the bone-like apatite that forms on the titania nanotubes after implantation are also affected by the diameter and shape. This review describes how changes in nanotube morphologies, such as the tube diameter, the thickness of the nanotube layer, and the crystalline structure, influence the response of cells.

  14. Titanium nanostructures for biomedical applications.

    PubMed

    Kulkarni, M; Mazare, A; Gongadze, E; Perutkova, Š; Kralj-Iglič, V; Milošev, I; Schmuki, P; A Iglič; Mozetič, M

    2015-02-13

    Titanium and titanium alloys exhibit a unique combination of strength and biocompatibility, which enables their use in medical applications and accounts for their extensive use as implant materials in the last 50 years. Currently, a large amount of research is being carried out in order to determine the optimal surface topography for use in bioapplications, and thus the emphasis is on nanotechnology for biomedical applications. It was recently shown that titanium implants with rough surface topography and free energy increase osteoblast adhesion, maturation and subsequent bone formation. Furthermore, the adhesion of different cell lines to the surface of titanium implants is influenced by the surface characteristics of titanium; namely topography, charge distribution and chemistry. The present review article focuses on the specific nanotopography of titanium, i.e. titanium dioxide (TiO2) nanotubes, using a simple electrochemical anodisation method of the metallic substrate and other processes such as the hydrothermal or sol-gel template. One key advantage of using TiO2 nanotubes in cell interactions is based on the fact that TiO2 nanotube morphology is correlated with cell adhesion, spreading, growth and differentiation of mesenchymal stem cells, which were shown to be maximally induced on smaller diameter nanotubes (15 nm), but hindered on larger diameter (100 nm) tubes, leading to cell death and apoptosis. Research has supported the significance of nanotopography (TiO2 nanotube diameter) in cell adhesion and cell growth, and suggests that the mechanics of focal adhesion formation are similar among different cell types. As such, the present review will focus on perhaps the most spectacular and surprising one-dimensional structures and their unique biomedical applications for increased osseointegration, protein interaction and antibacterial properties.

  15. Titanium nanostructures for biomedical applications

    NASA Astrophysics Data System (ADS)

    Kulkarni, M.; Mazare, A.; Gongadze, E.; Perutkova, Š.; Kralj-Iglič, V.; Milošev, I.; Schmuki, P.; Iglič, A.; Mozetič, M.

    2015-02-01

    Titanium and titanium alloys exhibit a unique combination of strength and biocompatibility, which enables their use in medical applications and accounts for their extensive use as implant materials in the last 50 years. Currently, a large amount of research is being carried out in order to determine the optimal surface topography for use in bioapplications, and thus the emphasis is on nanotechnology for biomedical applications. It was recently shown that titanium implants with rough surface topography and free energy increase osteoblast adhesion, maturation and subsequent bone formation. Furthermore, the adhesion of different cell lines to the surface of titanium implants is influenced by the surface characteristics of titanium; namely topography, charge distribution and chemistry. The present review article focuses on the specific nanotopography of titanium, i.e. titanium dioxide (TiO2) nanotubes, using a simple electrochemical anodisation method of the metallic substrate and other processes such as the hydrothermal or sol-gel template. One key advantage of using TiO2 nanotubes in cell interactions is based on the fact that TiO2 nanotube morphology is correlated with cell adhesion, spreading, growth and differentiation of mesenchymal stem cells, which were shown to be maximally induced on smaller diameter nanotubes (15 nm), but hindered on larger diameter (100 nm) tubes, leading to cell death and apoptosis. Research has supported the significance of nanotopography (TiO2 nanotube diameter) in cell adhesion and cell growth, and suggests that the mechanics of focal adhesion formation are similar among different cell types. As such, the present review will focus on perhaps the most spectacular and surprising one-dimensional structures and their unique biomedical applications for increased osseointegration, protein interaction and antibacterial properties.

  16. Cementless anatomical prosthesis for the treatment of 3-part and 4-part proximal humerus fractures: cadaver study and prospective clinical study with minimum 2 years followup

    PubMed Central

    Obert, Laurent; Saadnia, Rachid; Loisel, François; Uhring, Julien; Adam, Antoine; Rochet, Séverin; Clappaz, Pascal; Lascar, Tristan

    2016-01-01

    Introduction: The purpose of this study was to evaluate the functional and radiological outcomes of a cementless, trauma-specific locked stem for 3- and 4-part proximal humeral fractures. Materials and methods: This study consisted of two parts: a cadaver study with 22 shoulders and a multicenter prospective clinical study of 23 fracture patients evaluated at least 2 years after treatment. In the cadaver study, the locked stem (HumelockTM, FX Solutions) and its instrumentation were evaluated. In the clinical study, five senior surgeons at four different hospitals performed the surgical procedures. An independent surgeon evaluated the patients using clinical (Constant score, QuickDASH) and radiological (X-rays, CT scans) outcome measures. Results: The cadaver study allowed us to validate the height landmarks relative to the pectoralis major tendon. In the clinical study, at the review, abduction was 95° (60–160), forward flexion was 108° (70–160), external rotation (elbow at body) was 34° (0–55), the QuickDASH was 31 (4.5–59), the overall Constant score was 54 (27–75), and the weighted Constant score was 76 (31.5–109). Discussion: This preliminary study of hemiarthroplasty (HA) with a locked stem found results that were at least equivalent to published series. As all patients had at least a 2-year follow-up, integration of the locked stem did not cause any specific complications. These results suggest that it is possible to avoid using cement when hemiarthroplasty is performed for the humeral stem. This implant makes height adjustment and transosseous suturing of the tuberosities more reproducible. PMID:27194107

  17. Rifampicin-fosfomycin coating for cementless endoprostheses: antimicrobial effects against methicillin-sensitive Staphylococcus aureus (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA).

    PubMed

    Alt, Volker; Kirchhof, Kristin; Seim, Florian; Hrubesch, Isabelle; Lips, Katrin S; Mannel, Henrich; Domann, Eugen; Schnettler, Reinhard

    2014-10-01

    New strategies to decrease infection rates in cementless arthroplasty are needed, especially in the context of the growing incidence of methicillin-resistant Staphylococcus aureus (MRSA) infections. The purpose of this study was to investigate the antimicrobial activity of a rifampicin-fosfomycin coating against methicillin-sensitive Staphylococcus aureus (MSSA) and MRSA in a rabbit infection prophylaxis model. Uncoated or rifampicin-fosfomycin-coated K-wires were inserted into the intramedullary canal of the tibia in rabbits and contaminated with an inoculation dose of 10(5) or 10(6) colony-forming units of MSSA EDCC 5055 in study 1 and MRSA T6625930 in study 2, respectively. After 28days the animals were killed and clinical, histological and microbiological assessment, including pulse-field gel electrophoresis, was conducted. Positive culture growth in agar plate testing and/or clinical signs and/or histological signs were defined positive for infection. Statistical evaluation was performed using Fisher's exact test. Both studies showed a statistically significant reduction of infection rates for rifampicin-fosfomycin-coated implants compared to uncoated K-wires (P=0.015). In both studies none of the 12 animals that were treated with a rifampicin-fosfomycin-coated implant showed clinical signs of infection or a positive agar plate testing result. In both studies, one animal of the coating group showed the presence of sporadic bacteria with concomitant inflammatory signs in histology. The control groups in both studies exhibited an infection rate of 100% with clear clinical signs of infection and positive culture growth in all animals. In summary, the rifampicin-fosfomycin-coating showed excellent antimicrobial activity against both MSSA and MRSA, and therefore warrants further clinical testing.

  18. Method for Surface Texturing Titanium Products

    NASA Technical Reports Server (NTRS)

    Banks, Bruce A. (Inventor)

    1998-01-01

    The present invention teaches a method of producing a textured surface upon an arbitrarily configured titanium or titanium alloy object for the purpose of improving bonding between the object and other materials such as polymer matrix composites and/or human bone for the direct in-growth of orthopaedic implants. The titanium or titanium alloy object is placed in an electrolytic cell having an ultrasonically agitated solution of sodium chloride therein whereby a pattern of uniform "pock mark" like pores or cavities are produced upon the object's surface. The process is very cost effective compared to other methods of producing rough surfaces on titanium and titanium alloy components. The surface textures produced by the present invention are etched directly into the parent metal at discrete sites separated by areas unaffected by the etching process. Bonding materials to such surface textures on titanium or titanium alloy can thus support a shear load even if adhesion of the bonding material is poor.

  19. Titanium diaphragm makes excellent amplitron cathode support

    NASA Technical Reports Server (NTRS)

    Teich, W. W.

    1965-01-01

    Cathode support structure designed around a titanium diaphragm prevents radial misalignment between the cathode and anode in amplitrons. The titanium exhibits low thermal conductivity, tolerates lateral thermal expansion of the cathode, and is a poor primary and secondary emission medium.

  20. Titanium pigmentation. An electron probe microanalysis study

    SciTech Connect

    Dupre, A.; Touron, P.; Daste, J.; Lassere, J.; Bonafe, J.L.; Viraben, R.

    1985-05-01

    A patient had an unusual pigmentary disease induced by titanium dioxide. The use of a topical cream containing titanium dioxide caused a xanthomalike appearance on the patient's penis. Electron probe microanalysis was valuable in establishing the cause of this balanitis.

  1. Development of Lightweight Titanium Base Alloys

    DTIC Science & Technology

    1989-04-15

    program on Development of Lightweight Titanium Base Alloys was to develop new titanium alloys with 10% lower density, 50% higher elastic modulus, and...program. permitted the cvaluation of a low-dc-isity. dislicrsion-strengthcnicd 02 + y titanium aluminide , which has excellent high temperature strength...713e alloy has significantly higher strength than the titanium aluminides . The limited data for ’i-34AI-4Be show it to be very strong above 7(X)°C

  2. Process for reproducibly preparing titanium subhydride

    DOEpatents

    Carlson, Richard S.

    1982-01-01

    Titanium subhydride is produced in a reactor by heating a selected amount of finely divided titanium compound at a selected temperature for a selected period of time under dynamic vacuum conditions. Hydrogen is removed substantially uniformly from each powder grain and there is produced a subhydride of substantially uniform titanium-hydrogen composition. Selection of the amount, temperature and time produces a subhydride of selected titanium-hydrogen composition.

  3. Lightweight Protective Coatings For Titanium Alloys

    NASA Technical Reports Server (NTRS)

    Wiedemann, Karl E.; Taylor, Patrick J.; Clark, Ronald K.

    1992-01-01

    Lightweight coating developed to protect titanium and titanium aluminide alloys and titanium-matrix composite materials from attack by environment when used at high temperatures. Applied by sol-gel methods, and thickness less than 5 micrometers. Reaction-barrier and self-healing diffusion-barrier layers combine to protect titanium alloy against chemical attack by oxygen and nitrogen at high temperatures with very promising results. Can be extended to protection of other environmentally sensitive materials.

  4. 21 CFR 73.3126 - Titanium dioxide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Titanium dioxide. 73.3126 Section 73.3126 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Medical Devices § 73.3126 Titanium dioxide. (a) Identity and specifications. The color additive titanium dioxide (CAS Reg. No. 13463-67-7), Color Index No. 77891,...

  5. 40 CFR 180.1195 - Titanium dioxide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Titanium dioxide. 180.1195 Section 180.1195 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS... Titanium dioxide. Titanium dioxide is exempted from the requirement of a tolerance for residues in or...

  6. 21 CFR 73.575 - Titanium dioxide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Titanium dioxide. 73.575 Section 73.575 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Foods § 73.575 Titanium dioxide. (a) Identity. (1) The color additive titanium dioxide is synthetically prepared TiO2, free from admixture with other substances. (2)...

  7. 21 CFR 73.2575 - Titanium dioxide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Titanium dioxide. 73.2575 Section 73.2575 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2575 Titanium dioxide. (a) Identity and specifications. The color additive titanium dioxide shall conform in identity and specifications to the...

  8. 21 CFR 73.1575 - Titanium dioxide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Titanium dioxide. 73.1575 Section 73.1575 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1575 Titanium dioxide. (a) Identity and specifications. (1) The color additive titanium dioxide shall conform in identity and specifications to the...

  9. 40 CFR 180.1195 - Titanium dioxide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Titanium dioxide. 180.1195 Section 180.1195 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS... Titanium dioxide. Titanium dioxide is exempted from the requirement of a tolerance for residues in or...

  10. 21 CFR 73.1575 - Titanium dioxide.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Titanium dioxide. 73.1575 Section 73.1575 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1575 Titanium dioxide. (a) Identity and specifications. (1) The color additive titanium dioxide shall conform in identity and specifications to the...

  11. 21 CFR 73.3126 - Titanium dioxide.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Titanium dioxide. 73.3126 Section 73.3126 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Medical Devices § 73.3126 Titanium dioxide. (a) Identity and specifications. The color additive titanium dioxide (CAS Reg. No. 13463-67-7), Color Index No. 77891,...

  12. 21 CFR 73.2575 - Titanium dioxide.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Titanium dioxide. 73.2575 Section 73.2575 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2575 Titanium dioxide. (a) Identity and specifications. The color additive titanium dioxide shall conform in identity and specifications to the...

  13. 21 CFR 73.2575 - Titanium dioxide.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 1 2012-04-01 2012-04-01 false Titanium dioxide. 73.2575 Section 73.2575 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2575 Titanium dioxide. (a) Identity and specifications. The color additive titanium dioxide shall conform in identity and specifications to the...

  14. 21 CFR 73.2575 - Titanium dioxide.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 1 2013-04-01 2013-04-01 false Titanium dioxide. 73.2575 Section 73.2575 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2575 Titanium dioxide. (a) Identity and specifications. The color additive titanium dioxide shall conform in identity and specifications to the...

  15. 40 CFR 180.1195 - Titanium dioxide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 25 2013-07-01 2013-07-01 false Titanium dioxide. 180.1195 Section 180.1195 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS... Titanium dioxide. Titanium dioxide (CAS Reg. No. 13463-67-7) is exempted from the requirement of...

  16. 21 CFR 73.3126 - Titanium dioxide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 1 2014-04-01 2014-04-01 false Titanium dioxide. 73.3126 Section 73.3126 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Medical Devices § 73.3126 Titanium dioxide. (a) Identity and specifications. The color additive titanium dioxide (CAS Reg. No. 13463-67-7), Color Index No. 77891,...

  17. 21 CFR 73.1575 - Titanium dioxide.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 1 2013-04-01 2013-04-01 false Titanium dioxide. 73.1575 Section 73.1575 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1575 Titanium dioxide. (a) Identity and specifications. (1) The color additive titanium dioxide shall conform in identity and specifications to the...

  18. 21 CFR 73.1575 - Titanium dioxide.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 1 2012-04-01 2012-04-01 false Titanium dioxide. 73.1575 Section 73.1575 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1575 Titanium dioxide. (a) Identity and specifications. (1) The color additive titanium dioxide shall conform in identity and specifications to the...

  19. 21 CFR 73.2575 - Titanium dioxide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 1 2014-04-01 2014-04-01 false Titanium dioxide. 73.2575 Section 73.2575 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2575 Titanium dioxide. (a) Identity and specifications. The color additive titanium dioxide shall conform in identity and specifications to the...

  20. 40 CFR 180.1195 - Titanium dioxide.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 25 2012-07-01 2012-07-01 false Titanium dioxide. 180.1195 Section 180.1195 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS... Titanium dioxide. Titanium dioxide is exempted from the requirement of a tolerance for residues in or...

  1. 21 CFR 73.1575 - Titanium dioxide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 1 2014-04-01 2014-04-01 false Titanium dioxide. 73.1575 Section 73.1575 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1575 Titanium dioxide. (a) Identity and specifications. (1) The color additive titanium dioxide shall conform in identity and specifications to the...

  2. 40 CFR 180.1195 - Titanium dioxide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Titanium dioxide. 180.1195 Section 180.1195 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS... Titanium dioxide. Titanium dioxide (CAS Reg. No. 13463-67-7) is exempted from the requirement of...

  3. Yttria Nanoparticle Reinforced Commercially Pure (CP) Titanium

    DTIC Science & Technology

    2011-09-01

    nanoparticles as well as titanium boride (TiB) reinforcements were produced through gas atomization. After consolidation and extrusion, room temperature...pure FE iron O oxygen Ti titanium TiB titanium boride TYS tensile yield strength UTS ultimate tensile strength wt% weight percent Y2O3

  4. Photonuclear reactions on titanium isotopes

    SciTech Connect

    Belyshev, S. S.; Dzhilavyan, L. Z.; Ishkhanov, B. S.; Kapitonov, I. M.; Kuznetsov, A. A. Orlin, V. N.; Stopani, K. A.

    2015-03-15

    The photodisintegration of titanium isotopes in the giant-dipole-resonance energy region is studied by the photon-activation method. Bremsstrahlung photons whose spectrum has the endpoint energy of 55 MeV is used. The yields and integrated cross sections are determined for photoproton reactions on the titanium isotopes {sup 47,48,49,50}Ti. The respective experimental results are compared with their counterparts calculated on the basis of the TALYS code and a combined photonucleon-reaction model. The TALYS code disregards the isospin structure of the giant dipole resonance and is therefore unable to describe the yield of photoproton reactions on the heavy titanium isotopes {sup 49,50}Ti.

  5. Adaptive mesh refinement in titanium

    SciTech Connect

    Colella, Phillip; Wen, Tong

    2005-01-21

    In this paper, we evaluate Titanium's usability as a high-level parallel programming language through a case study, where we implement a subset of Chombo's functionality in Titanium. Chombo is a software package applying the Adaptive Mesh Refinement methodology to numerical Partial Differential Equations at the production level. In Chombo, the library approach is used to parallel programming (C++ and Fortran, with MPI), whereas Titanium is a Java dialect designed for high-performance scientific computing. The performance of our implementation is studied and compared with that of Chombo in solving Poisson's equation based on two grid configurations from a real application. Also provided are the counts of lines of code from both sides.

  6. 76 FR 52313 - Heavy Forged Hand Tools (i.e., Axes & Adzes, Bars & Wedges, Hammers & Sledges, and Picks...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-22

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF COMMERCE International Trade Administration Heavy Forged Hand Tools (i.e., Axes & Adzes, Bars & Wedges, Hammers & Sledges... AGENCY: Import Administration, International Trade Administration, Department of Commerce. SUMMARY: As...

  7. Effects of Cryogenic Forging and Anodization on the Mechanical Properties of AA 7075-T73 Aluminum Alloys

    NASA Astrophysics Data System (ADS)

    Shih, Teng-Shih; Liao, Tien-Wei; Hsu, Wen-Nong

    2016-03-01

    In this study, high-strength AA7075 alloy samples were cryogenically forged after annealing and then subjected to solution and aging treatments. The cryogenically forged 7075-T73 alloy samples displayed equiaxed fine grains associated with abundant fine precipitates in their matrix. Compared with conventional 7075-T73 alloy samples, the cryogenically forged samples exhibited an 8-12% reduction in tensile strength and an increased fatigue strength and higher corrosion resistance. The fatigue strength measured at 107 cycles was 225 MPa in the bare samples; the strength was increased to 250 MPa in the cryogenically forged samples. The effect of anodization on the corrosion resistance of the bare samples was improved from (E corr) -0.80 to -0.61 V.

  8. Thermal Stir Welds in Titanium

    NASA Astrophysics Data System (ADS)

    Fonda, Richard W.; Knipling, Keith E.; Pilchak, Adam L.

    2016-01-01

    Although conventional friction stir welding (FSW) has proven unsuccessful in joining thick sections of alpha and near-alpha titanium alloys, thermal stir welding, a variant of the FSW process in which an external heat source is used to preheat the workpiece, is demonstrated to be able to reliably join 12.3-mm-thick plates of CP titanium. This paper describes the microstructures and textures that develop in these thermal stir welds. The observed microstructure was used to reconstruct the high-temperature microstructure and texture present during the welding process and therefore reveal the genesis of the welding structures.

  9. Effect of whitening toothpaste on titanium and titanium alloy surfaces.

    PubMed

    Faria, Adriana Cláudia Lapria; Bordin, Angelo Rafael de Vito; Pedrazzi, Vinícius; Rodrigues, Renata Cristina Silveira; Ribeiro, Ricardo Faria

    2012-01-01

    Dental implants have increased the use of titanium and titanium alloys in prosthetic applications. Whitening toothpastes with peroxides are available for patients with high aesthetic requirements, but the effect of whitening toothpastes on titanium surfaces is not yet known, although titanium is prone to fluoride ion attack. Thus, the aim of the present study was to compare Ti-5Ta alloy to cp Ti after toothbrushing with whitening and conventional toothpastes. Ti-5Ta (%wt) alloy was melted in an arc melting furnace and compared with cp Ti. Disks and toothbrush heads were embedded in PVC rings to be mounted onto a toothbrushing test apparatus. A total of 260,000 cycles were carried out at 250 cycles/minute under a load of 5 N on samples immersed in toothpaste slurries. Surface roughness and Vickers microhardness were evaluated before and after toothbrushing. One sample of each material/toothpaste was analyzed by Scanning Electron Microscopy (SEM) and compared with a sample that had not been submitted to toothbrushing. Surface roughness increased significantly after toothbrushing, but no differences were noted after toothbrushing with different toothpastes. Toothbrushing did not significantly affect sample microhardness. The results suggest that toothpastes that contain and those that do not contain peroxides in their composition have different effects on cp Ti and Ti-5Ta surfaces. Although no significant difference was noted in the microhardness and roughness of the surfaces brushed with different toothpastes, both toothpastes increased roughness after toothbrushing.

  10. Research and Development on Titanium Alloys

    DTIC Science & Technology

    1949-10-31

    svmym lIfe. Th~e rAnge of cOmposila Ivwstpted in the bin"rtniaum-stiver sistems was extended to 5% snw an M~an~Ajmm loy cntprn 0.1 Is beryllium were...extended to 5,0 per cent silverl and titanium- beryllium alloys containing 0.1 to-1.0 per cent berylliuma were inveitiga~ted. None of~ these alloys had...of: 1. Binary titanium-germanium alloys. 2. Binary titanium-nickel alloys. 3, Binary titanium-silver alloys. 4. Binary titanium- beryllium alloys. 5

  11. Numerical simulation and experimental study for the die forging process of a high-speed railway brake disc hub

    NASA Astrophysics Data System (ADS)

    Sun, Mingyue; Xu, Bin; Zhang, Long; LI, Dianzhong

    2013-05-01

    With the aim of manufacturing a near-net shape forging product of a brake disk hub for the high-speed railway, the die forging process was designed and optimized in this study. Firstly, based on the measured stress-strain curves at different strain rates and the thermal-physical parameters of 40Cr A steel, a finite element model for the forging process of a high-speed railway brake disc hub was established. Then, the temperature, stress and strain fields were studied and analyzed at the pre-forging and the finial-forging stages. Besides, in order to trace the stress and strain evolution, five points at different positions were chosen on the billet, and the comparison of the state conditions was made among these points. The results have demonstrated that the product can be well formed by an elaborately designed three-stage forging process, which may reduce the metal machine allowance and the producing cost effectively. Finally, an industrial trial was made and a machined product with sound quality was obtained.

  12. Porosity, Microstructure, and Mechanical Properties of Ti-6Al-4V Alloy Parts Fabricated by Powder Compact Forging

    NASA Astrophysics Data System (ADS)

    Jia, Mingtu; Zhang, Deliang; Liang, Jiamiao; Gabbitas, Brian

    2017-04-01

    Ti-6Al-4V alloy powders produced using a hydrogenation-dehydrogenation process and a gas atomization process, respectively, were rapidly consolidated into near-net-shaped parts by powder compact forging. The porosity, microstructure, and tensile mechanical properties of specimens cut from regions at different distances from the side surfaces of the forged parts were examined. The regions near the side surfaces contained a fraction of pores due to the circumferential tensile strain arising during the powder compact forging process, and the porosity level decreased rapidly to zero with increasing the distance from the side surface. The forged parts had a fully lamellar structure with the α + β colony sizes and α lamella thickness changing little with the distance from the side surface. The specimens cut from the regions near the side surfaces had a lower yield strength and tensile strength. The correlation of porosity with the yield strength of the specimens suggested that the reduction of load bearing areas due to the porosity and unbonded or weakly bonded interparticle boundaries was not the only reason for the lower strength, and the stress concentration at the pores and associated with their geometry also played an important role in this. It is likely that the effect of stress concentration on yield strength reduction of the forged part increases with oxygen content. The Hall-Petch relationship of the yield strength and the average α lamella thickness suggested that the strength of the fully dense and fully consolidated forged parts was increased by oxygen solution strengthening.

  13. Porosity, Microstructure, and Mechanical Properties of Ti-6Al-4V Alloy Parts Fabricated by Powder Compact Forging

    NASA Astrophysics Data System (ADS)

    Jia, Mingtu; Zhang, Deliang; Liang, Jiamiao; Gabbitas, Brian

    2017-01-01

    Ti-6Al-4V alloy powders produced using a hydrogenation-dehydrogenation process and a gas atomization process, respectively, were rapidly consolidated into near-net-shaped parts by powder compact forging. The porosity, microstructure, and tensile mechanical properties of specimens cut from regions at different distances from the side surfaces of the forged parts were examined. The regions near the side surfaces contained a fraction of pores due to the circumferential tensile strain arising during the powder compact forging process, and the porosity level decreased rapidly to zero with increasing the distance from the side surface. The forged parts had a fully lamellar structure with the α + β colony sizes and α lamella thickness changing little with the distance from the side surface. The specimens cut from the regions near the side surfaces had a lower yield strength and tensile strength. The correlation of porosity with the yield strength of the specimens suggested that the reduction of load bearing areas due to the porosity and unbonded or weakly bonded interparticle boundaries was not the only reason for the lower strength, and the stress concentration at the pores and associated with their geometry also played an important role in this. It is likely that the effect of stress concentration on yield strength reduction of the forged part increases with oxygen content. The Hall-Petch relationship of the yield strength and the average α lamella thickness suggested that the strength of the fully dense and fully consolidated forged parts was increased by oxygen solution strengthening.

  14. Development of expert systems for the design of a hot-forging process based on material workability

    NASA Astrophysics Data System (ADS)

    Ravi, R.; Prasad, Y. V. R. K.; Sarma, V. V. S.

    2003-12-01

    Most of the time (and cost) involved in planning hot forging process is related to activities strongly dependent on human expertise, intuition, and creativity, and also to iterative procedure involving extensive experimental work. In this paper, the development of an expert system for forging process design, which emphasizes materials’ workability, is discussed. Details of the forging process design expert system, its basic modules, design and implementation details, and deliverables are explained. The system uses the vast database available on the hot workability of more than 200 technologically important materials and the knowledge acquired from a materials’ expert. The C Language Integrated Production System (CLIPS) has been adopted to develop this expert system. The expert system can address three types of functions, namely, forging process design, materials information system, and forging defect analysis. The expert system will aid and prompt a novice engineer in designing a forging process by providing accurate information of the process parameters, lubricants, type of machine, die material, and type of process (isothermal versus non-isothermal) for a given material with a known specification or code and prior history.

  15. Effect of Hot Forging on Microstructural Evolution and Impact Toughness in Ultra-high Carbon Low Alloy Steel

    NASA Astrophysics Data System (ADS)

    Kim, J. B.; Kim, J. H.; Kang, C. Y.

    2016-12-01

    The effect of a hot forging ratio on the microstructural variation and tensile properties of ultra-high carbon low alloy steel was investigated. Scanning electron microscopic analyses depict that with an increase in the hot forging ratio, the thickness of the network and acicular proeutectoid cementite decreased. Moreover, the lamella spacing and thickness of the eutectoid cementite decreased and broke up into particle shapes, which then became spheroidized as the hot forging ratio increased. Furthermore, when the forging ratio exceeded 65%, the network and acicular shape of the as-cast state disappeared. By increasing the hot forging ratio, the tensile strength and elongation remained below 50%, but they increased rapidly with an increase in the forging ratio. Strength and elongation were not affected by the thickness of the proeutectoid and eutectoid cementites, but were greatly affected by the shape of the proeutectoid cementite. Due to the decrease in the austenite grain size, as well as the spheroidization of the cementite, the tensile strength and elongation sharply increased.

  16. Effect of forging strain rate and deformation temperature on the mechanical properties of warm-worked 304L stainless steel

    SciTech Connect

    Switzner, N. T.; Van Tyne, C. J.; Mataya, M. C.

    2010-01-25

    Stainless steel 304L forgings were produced with four different types of production forging equipment – hydraulic press, mechanical press, screw press, and high-energy rate forging (HERF). Each machine imparted a different nominal strain rate during the deformation. The final forgings were done at the warm working (low hot working) temperatures of 816 °C, 843°C, and 871°C. The objectives of the study were to characterize and understand the effect of industrial strain rates (i.e. processing equipment), and deformation temperature on the mechanical properties for the final component. Some of the components were produced with an anneal prior to the final forging while others were deformed without the anneal. The results indicate that lower strain rates produced lower strength and higher ductility components, but the lower strain rate processes were more sensitive to deformation temperature variation and resulted in more within-part property variation. The highest strain rate process, HERF, resulted in slightly lower yield strength due to internal heating. Lower processing temperatures increased strength, decreased ductility but decreased within-part property variation. The anneal prior to the final forging produced a decrease in strength, a small increase in ductility, and a small decrease of within-part property variation.

  17. Application of multi-grid method on the simulation of incremental forging processes

    NASA Astrophysics Data System (ADS)

    Ramadan, Mohamad; Khaled, Mahmoud; Fourment, Lionel

    2016-10-01

    Numerical simulation becomes essential in manufacturing large part by incremental forging processes. It is a splendid tool allowing to show physical phenomena however behind the scenes, an expensive bill should be paid, that is the computational time. That is why many techniques are developed to decrease the computational time of numerical simulation. Multi-Grid method is a numerical procedure that permits to reduce computational time of numerical calculation by performing the resolution of the system of equations on several mesh of decreasing size which allows to smooth faster the low frequency of the solution as well as its high frequency. In this paper a Multi-Grid method is applied to cogging process in the software Forge 3. The study is carried out using increasing number of degrees of freedom. The results shows that calculation time is divide by two for a mesh of 39,000 nodes. The method is promising especially if coupled with Multi-Mesh method.

  18. Fatigue life on a full scale test rig: Forged versus cast wind turbine rotor shafts

    NASA Astrophysics Data System (ADS)

    Herrmann, J.; Rauert, T.; Dalhoff, P.; Sander, M.

    2016-09-01

    To reduce uncertainties associated with the fatigue life of the highly safety relevant rotor shaft and also to review today's design practice, the fatigue behaviour will be tested on a full scale test rig. Until now tests on full scale wind turbine parts are not common. Therefore, a general lack of experience on how to perform accelerated life time tests for those components exists. To clarify how to transfer real conditions to the test environment, the arrangements and deviations for the upcoming experimental test are discussed in detail. In order to complete investigations of weight saving potentials, next to getting a better comprehension of the fatigue behaviour by executing a full scale test, a further outcome are suggestions for the usage of cast and forged materials regarding the fatigue and the remaining life of the rotor shaft. It is shown, that it is worthwhile to think about a material exchange for the forged rotor shaft.

  19. HYDROGEN EFFECTS ON THE FRACTURE TOUGHNESS PROPERTIES OF FORGED STAINLESS STEELS

    SciTech Connect

    Morgan, M

    2008-03-28

    The effect of hydrogen on the fracture toughness properties of Types 304L, 316L and 21-6-9 forged stainless steels was investigated. Fracture toughness samples were fabricated from forward-extruded forgings. Samples were uniformly saturated with hydrogen after exposure to hydrogen gas at 34 MPa or 69 and 623 K prior to testing. The fracture toughness properties were characterized by measuring the J-R behavior at ambient temperature in air. The results show that the hydrogen-charged steels have fracture toughness values that were about 50-60% of the values measured for the unexposed steels. The reduction in fracture toughness was accompanied by a change in fracture appearance. Both uncharged and hydrogen-charged samples failed by microvoid nucleation and coalescence, but the fracture surfaces of the hydrogen-charged steels had smaller microvoids. Type 316L stainless steel had the highest fracture toughness properties and the greatest resistance to hydrogen degradation.

  20. Assembled camshaft for I. C. engines with forged powder metal cams

    SciTech Connect

    Lugosi, R.; Brauer, M.; Cook, J.

    1987-01-01

    A key element in the Automotive Industry's efforts to improve fuel economy and engine performance is the introduction of roller tappets to reduce friction in valve trains. As a result, contact stresses in excess of 200,000 psi may be experienced at the roller and cam (shaft) interface. Conventional cast iron camshafts cannot effectively carry this stress level. After studying several alternatives, the authors have developed a camshaft which promises to be a viable solution to the problem, both technically and economically. The purpose of this work was to demonstrate the acceptable wear performance of an assembled camshaft containing forged powder metal lobes in a series of motored engine tests with roller hydraulic valve train. In this study, a camshaft consisting of a carbon steel tube and forged powder metal lobes (4660 composition) joined by brazing was tested at low speed and at high speed in a motored engine at approximately 250,000 psi maximum contact stress.

  1. FEM analysis of spur gears forging from nano-structured materials

    NASA Astrophysics Data System (ADS)

    Salcedo, D.; Luis-Pérez, C. J.; Luri, R.; León, J.

    2012-04-01

    The ECAE process is a novel technology which allows us to obtain materials with sub-micrometric and/or nanometric grain size as a result of accumulating very high levels of plastic deformation in the presence of a high hydrostatic pressure. This avoids the fracture of the material and allows us to obtain very high values of plastic deformation (ɛ >>1). Therefore, these nano-structured materials can be used as starting materials for other manufacturing processes such as: extrusion, rolling and forging, among others; with the advantage of providing nanostructure and hence, improved mechanical properties. In this present work, the forging by finite element method (FEM) of materials that have been previously processed by ECAE is analyzed. MSC. MarcTM software will be employed with the aim of analyzing the possibility of manufacturing mechanical components (spur gears) from materials nano-structured by ECAE.

  2. Effect of multiaxial forging on microstructure and mechanical properties of Mg-o.8Ca alloy

    NASA Astrophysics Data System (ADS)

    Yurchenko, N. Yu; Stepanov, N. D.; Salishchev, G. A.; Rokhlin, L. L.; Dobatkin, S. V.

    2014-08-01

    It was shown that multiaxial forging with continuous decrease of temperature from 450°C to 250°C turns coarse structure of the Mg-0.8Ca alloy in homogenized state with grain size of several hundreeds gm into fine structure with average grain size of about 2.1 gm. Refinement of structure is accompanied by drastic increase of mechanical properties: tensile yield strength increases from 50 MPa to 193 MPa, ultimate tensile strength increases from 78 to 308 MPa and elongation to fracture increases from 3.0% to 7.2%. The microstructural evolution during multiaxial forging is studied using optical microscopy, scanning electron microscopy and EBSD analysis. The mechanisms responsible for refinement of microstructure are discussed

  3. Evolution of the Ultrasonic Inspection of Heavy Rotor Forgings Over the Last Decades

    NASA Astrophysics Data System (ADS)

    Zimmer, A.; Vrana, J.; Meiser, J.; Maximini, W.; Blaes, N.

    2010-02-01

    All types of heavy forgings that are used in energy machine industry, rotor shafts as well as discs, retaining rings or tie bolts are subject to extensive nondestructive inspections before they are delivered to the customer. Due to the availability of the parts in simple shapes, these forgings are very well suited for full volmetric inspections using ultrasound. In the beginning, these inspections were carried out manually, using straight beam probes and analogue equipment. Higher requirements in reliability, efficiency, safety and power output in the machines have lead to higher requirements for the ultrasonic inspection in the form of more scanning directions, higher sensitivity demands and improved documentation means. This and the increasing use of high alloy materials for ever growing parts, increase the need for more and more sophisticated methods for testing the forgings. Angle scans and sizing technologies like DGS have been implemented, and for more than 15 years now, mechanized and automated inspections have gained importance since they allow better documentation as well as easier evaluation of the recorded data using different views (B- C- or D-Scans), projections or tomography views. The latest major development has been the availability of phased array probes to increase the flexibility of the inspection systems. Many results of the ongoing research in ultrasonic's have not been implemented yet. Today's availability of fast computers, large and fast data storages allows saving RF inspection data and applying sophisticated signal processing methods. For example linear diffraction tomography methods like SAFT offer tools for 3D reconstruction of inspection data, simplifying sizing and locating of defects as well as for improving signal to noise ratios. While such methods are already applied in medical ultrasonic's, they are still to be implemented in the steel industry. This paper describes the development of the ultrasonic inspection of heavy forgings

  4. Forging an American Grand Strategy: Securing a Path Through a Complex Future

    DTIC Science & Technology

    2013-10-01

    public opinion, nuclear proliferation, civil-military relations , information warfare, and U.S. national security. Dr. Ferber holds a Ph.D. from Harvard...USAWC WebsiteSSI WebsiteThis Publication U.S. ARMY WAR COLLEGE Forging an Am erican G rand Strategy: Securing a Path Through a Com plex Future...and UNITED STATES ARMY WAR COLLEGE PRESS Visit our website for other free publication downloads http://www.StrategicStudiesInstitute.army.mil/ To

  5. Synthesis and properties of nanoscale titanium boride

    NASA Astrophysics Data System (ADS)

    Efimova, K. A.; Galevskiy, G. V.; Rudneva, V. V.

    2015-09-01

    This work reports the scientific and technological grounds for plasma synthesis of titanium diboride, including thermodynamic and kinetic conditions of boride formation when titanium and titanium dioxide are interacting with products resulting from boron gasification in the nitrogen - hydrogen plasma flow, and two variations of its behavior using the powder mixtures: titanium - boron and titanium dioxide - boron. To study these technology variations, the mathematical models were derived, describing the relation between element contents in the synthesized products of titanium and free boron and basic parameters. The probable mechanism proposed for forming titanium diboride according to a "vapour - melt - crystal" pattern was examined, covering condensation of titanium vapour in the form of aerosol, boriding of nanoscale melt droplets by boron hydrides and crystallization of titanium - boron melt. The comprehensive physical - chemical certification of titanium diboride was carried out, including the study of its crystal structure, phase and chemical composition, dispersion, morphology and particle oxidation. Technological application prospects for use of titanium diboride nanoscale powder as constituent element in the wettable coating for carbon cathodes having excellent physical and mechanical performance and protective properties.

  6. Hydrogen content in titanium and a titanium-zirconium alloy after acid etching.

    PubMed

    Frank, Matthias J; Walter, Martin S; Lyngstadaas, S Petter; Wintermantel, Erich; Haugen, Håvard J

    2013-04-01

    Dental implant alloys made from titanium and zirconium are known for their high mechanical strength, fracture toughness and corrosion resistance in comparison with commercially pure titanium. The aim of the study was to investigate possible differences in the surface chemistry and/or surface topography of titanium and titanium-zirconium surfaces after sand blasting and acid etching. The two surfaces were compared by X-ray photoelectron spectroscopy, secondary ion mass spectroscopy, scanning electron microscopy and profilometry. The 1.9 times greater surface hydrogen concentration of titanium zirconium compared to titanium was found to be the major difference between the two materials. Zirconium appeared to enhance hydride formation on titanium alloys when etched in acid. Surface topography revealed significant differences on the micro and nanoscale. Surface roughness was increased significantly (p<0.01) on the titanium-zirconium alloy. High-resolution images showed nanostructures only present on titanium zirconium.

  7. 2016 Accomplishments. Tritium aging studies on stainless steel. Forging process effects on the fracture toughness properties of tritium-precharged stainless steel

    SciTech Connect

    Morgan, Michael J.

    2017-01-01

    Forged austenitic stainless steels are used as the materials of construction for pressure vessels designed to contain tritium at high pressure. These steels are highly resistant to tritium-assisted fracture but their resistance can depend on the details of the forging microstructure. During FY16, the effects of forging strain rate and deformation temperature on the fracture toughness properties of tritium-exposed-and-aged Type 304L stainless steel were studied. Forgings were produced from a single heat of steel using four types of production forging equipment – hydraulic press, mechanical press, screw press, and high-energy-rate forging (HERF). Each machine imparted a different nominal strain rate during the deformation. The objective of the study was to characterize the J-Integral fracture toughness properties as a function of the industrial strain rate and temperature. The second objective was to measure the effects of tritium and decay helium on toughness. Tritium and decay helium effects were measured by thermally precharging the as-forged specimens with tritium gas at 34.5 MPa and 350°C and aging for up to five years at -80°C to build-in decay helium prior to testing. The results of this study show that the fracture toughness properties of the as-forged steels vary with forging strain rate and forging temperature. The effect is largely due to yield strength as the higher-strength forgings had the lower toughness values. For non-charged specimens, fracture toughness properties were improved by forging at 871°C versus 816°C and Screw-Press forgings tended to have lower fracture toughness values than the other forgings. Tritium exposures reduced the fracture toughness values remarkably to fracture toughness values averaging 10-20% of as-forged values. However, forging strain rate and temperature had little or no effect on the fracture toughness after tritium precharging and aging. The result was confirmed by fractography which indicated that fracture modes

  8. Forming limit prediction of powder forging process by the energy-based elastoplastic damage model

    NASA Astrophysics Data System (ADS)

    Yeh, Hung-Yang; Cheng, Jung-Ho; Huang, Cheng-Chao

    2004-06-01

    An energy-based elastoplastic damage model is developed and then applied to predict the deformation and fracture initiation in powder forging processes. The fracture mechanism is investigated by the newly proposed damage model, which is based on the plastic energy dissipation. The developed formulations are implemented into finite element program ABAQUS in order to simulate the complex loading conditions. The forming limits of sintered porous metals under various operational conditions are explored by comparing the relevant experiments with the finite element analyses. The sintered iron-powder preforms of various initial relative densities (RDs) and aspect ratios are compressed until crack initiates. The deformation level of the bulged billets at fracture stroke obtained from compressive fracture tests is utilized to validate the finite element model and then the forming limit diagrams are constructed with the validated model. This model is further verified by the gear blank forging. The fracture site and corresponding deformation level are predicted by the finite element simulations. Meanwhile, the gear forging experiment is performed on the sintered preforms. The predicted results agree well with the experimental observations.

  9. Simulations and Experiments of the Nonisothermal Forging Process of a Ti-6Al-4V Impeller

    NASA Astrophysics Data System (ADS)

    Prabhu, T. Ram

    2016-09-01

    In the present study, a nonisothermal precision forging process of a Ti-6Al-4V first-stage impeller for the gas turbine engine was simulated using the finite element software. The simulation results such as load requirements, damage, velocity field, stress, strain, and temperature distributions are discussed in detail. Simulations predicted the maximum load requirement of about 80 MN. The maximum temperature loss was observed at the contour surface regions. The center and contour regions are the high-strained regions in the part. To validate the model, forging experiments mimicking simulations were performed in the α + β phases region (930 °C). The selected locations of the part were characterized for tensile properties at 27 and 200 °C, hardness, microstructure, grain size, and the amount of primary α phase based on the strain distribution results. The soundness of the forged part was verified using fluorescent penetrant test (Mil Std 2175 Grade A) and ultrasonic test (AMS 2630 class A1). From the experimental results, it was found that the variations in the hardness, tensile properties at room, and elevated temperature are not significant. The microstructure, grain size, and primary α phase content are nearly same.

  10. FEA Based Tool Life Quantity Estimation of Hot Forging Dies Under Cyclic Thermo-Mechanical Loads

    NASA Astrophysics Data System (ADS)

    Behrens, B.-A.; Bouguecha, A.; Schäfer, F.; Hadifi, T.

    2011-01-01

    Hot forging dies are exposed during service to a combination of cyclic thermo-mechanical, tribological and chemical loads. Besides abrasive and adhesive wear on the die surface, fatigue crack initiation with subsequent fracture is one of the most frequent causes of failure. In order to extend the tool life, the finite element analysis (FEA) may serve as a means for process design and process optimisation. So far the FEA based estimation of the production cycles until initial cracking is limited as tool material behaviour due to repeated loading is not captured with the required accuracy. Material models which are able to account for cyclic effects are not verified for the fatigue life predictions of forging dies. Furthermore fatigue properties from strain controlled fatigue tests of relevant hot work steels are to date not available to allow for a close-to-reality fatigue life prediction. Two industrial forging processes, where clear fatigue crack initiation has been observed are considered for a fatigue analysis. For this purpose the relevant tool components are modelled with elasto-plastic material behaviour. The predicted sites, where crack initiation occurs, agree with the ones observed on the real die component.

  11. An Approach to Optimize Size Parameters of Forging by Combining Hot-Processing Map and FEM

    NASA Astrophysics Data System (ADS)

    Hu, H. E.; Wang, X. Y.; Deng, L.

    2014-11-01

    The size parameters of 6061 aluminum alloy rib-web forging were optimized by using hot-processing map and finite element method (FEM) based on high-temperature compression data. The results show that the stress level of the alloy can be represented by a Zener-Holloman parameter in a hyperbolic sine-type equation with the hot deformation activation energy of 343.7 kJ/mol. Dynamic recovery and dynamic recrystallization concurrently preceded during high-temperature deformation of the alloy. Optimal hot-processing parameters for the alloy corresponding to the peak value of 0.42 are 753 K and 0.001 s-1. The instability domain occurs at deformation temperature lower than 653 K. FEM is an available method to validate hot-processing map in actual manufacture by analyzing the effect of corner radius, rib width, and web thickness on workability of rib-web forging of the alloy. Size parameters of die forgings can be optimized conveniently by combining hot-processing map and FEM.

  12. Computer-assisted Rheo-forging Processing of A356 Aluminum Alloys

    NASA Astrophysics Data System (ADS)

    Kim, H. H.; Kang, C. G.

    2010-06-01

    Die casting process has been used widely for complex automotive products such as the knuckle, arm and etc. Generally, a part fabricated by casting has limited strength due to manufacturing defects by origin such as the dendrite structure and segregation. As an attempt to offer a solution to these problems, forging has been used as an alternative process. However, the forging process provides limited formability for complex shape products. Rheo-forging of metal offers not only superior mechanical strength but also requires significantly lower machine loads than solid forming processes. In order to produce semi-solid materials of the desired microstructure, a stirring process is applied during solidification of A356 aluminum molten state. This paper presents the results of an A356 aluminum alloy sample, which were obtained by experiment and by simulation using DEFORM 3D V6.1. Samples of metal parts were subsequently fabricated by using hydraulic press machinery. In order to compare the influence of loading method, two types of samples were fabricated: (1) samples fabricated under direct loading die sets (2) those fabricated under indirect loading die sets. The formability and defects, which were predicted by FEM simulation, were similar to those of samples used in practice.

  13. Non-destructive Testing of Forged Metallic Materials by Active Infrared Thermography

    NASA Astrophysics Data System (ADS)

    Maillard, S.; Cadith, J.; Bouteille, P.; Legros, G.; Bodnar, J. L.; Detalle, V.

    2012-11-01

    Nowadays, infrared thermography is considered as the reference method in many applications such as safety, the inspection of electric installations, or the inspection of buildings' heat insulation. In recent years, the evolution of both material and data-processing tools also allows the development of thermography as a real non-destructive testing method. Thus, by subjecting the element to be inspected to an external excitation and by analyzing the propagation of heat in the examined zone, it is possible to highlight surface or subsurface defects such as cracks, delaminations, or corrosion. One speaks then about active infrared thermography. In this study, some results obtained during the collective studies carried out by CETIM and the University of Reims for the forging industry are presented. Various experimental possibilities offered by active thermography are presented and the interest in this method in comparison with the traditional non-destructive testing methods (penetrant testing and magnetic particle inspection) is discussed. For example, comparative results on a forged cracked hub, a steering joint, and a threaded rod are presented. They highlight the interest of infrared thermography stimulated by induction for forged parts.

  14. Experimental and Numerical Investigation of Forging Process to Reproduce a 3D Aluminium Foam Complex Shape

    SciTech Connect

    Filice, Luigino; Gagliardi, Francesco; Umbrello, Domenico; Shivpuri, Rajiv

    2007-05-17

    Metallic foams represent one of the most exciting materials introduced in the manufacturing scenario in the last years. In the study here addressed, the experimental and numerical investigations on the forging process of a simple foam billet shaped into complex sculptured parts were carried out. In particular, the deformation behavior of metallic foams and the development of density gradients were investigated through a series of experimental forging tests in order to produce a selected portion of a hip prosthesis. The human bone replacement was chosen as case study due to its industrial demand and for its particular 3D complex shape. A finite element code (Deform 3D) was utilized for modeling the foam behavior during the forging process and an accurate material rheology description was used based on a porous material model which includes the measured local density. Once the effectiveness of the utilized Finite Element model was verified through the comparison with the experimental evidences, a numerical study of the influence of the foam density was investigated. The obtained numerical results shown as the initial billet density plays an important role on the prediction of the final shape, the optimization of the flash as well as the estimation of the punch load.

  15. eFORGE: A Tool for Identifying Cell Type-Specific Signal in Epigenomic Data.

    PubMed

    Breeze, Charles E; Paul, Dirk S; van Dongen, Jenny; Butcher, Lee M; Ambrose, John C; Barrett, James E; Lowe, Robert; Rakyan, Vardhman K; Iotchkova, Valentina; Frontini, Mattia; Downes, Kate; Ouwehand, Willem H; Laperle, Jonathan; Jacques, Pierre-Étienne; Bourque, Guillaume; Bergmann, Anke K; Siebert, Reiner; Vellenga, Edo; Saeed, Sadia; Matarese, Filomena; Martens, Joost H A; Stunnenberg, Hendrik G; Teschendorff, Andrew E; Herrero, Javier; Birney, Ewan; Dunham, Ian; Beck, Stephan

    2016-11-15

    Epigenome-wide association studies (EWAS) provide an alternative approach for studying human disease through consideration of non-genetic variants such as altered DNA methylation. To advance the complex interpretation of EWAS, we developed eFORGE (http://eforge.cs.ucl.ac.uk/), a new standalone and web-based tool for the analysis and interpretation of EWAS data. eFORGE determines the cell type-specific regulatory component of a set of EWAS-identified differentially methylated positions. This is achieved by detecting enrichment of overlap with DNase I hypersensitive sites across 454 samples (tissues, primary cell types, and cell lines) from the ENCODE, Roadmap Epigenomics, and BLUEPRINT projects. Application of eFORGE to 20 publicly available EWAS datasets identified disease-relevant cell types for several common diseases, a stem cell-like signature in cancer, and demonstrated the ability to detect cell-composition effects for EWAS performed on heterogeneous tissues. Our approach bridges the gap between large-scale epigenomics data and EWAS-derived target selection to yield insight into disease etiology.

  16. Computer-assisted Rheo-forging Processing of A356 Aluminum Alloys

    SciTech Connect

    Kim, H. H.; Kang, C. G.

    2010-06-15

    Die casting process has been used widely for complex automotive products such as the knuckle, arm and etc. Generally, a part fabricated by casting has limited strength due to manufacturing defects by origin such as the dendrite structure and segregation. As an attempt to offer a solution to these problems, forging has been used as an alternative process. However, the forging process provides limited formability for complex shape products. Rheo-forging of metal offers not only superior mechanical strength but also requires significantly lower machine loads than solid forming processes. In order to produce semi-solid materials of the desired microstructure, a stirring process is applied during solidification of A356 aluminum molten state. This paper presents the results of an A356 aluminum alloy sample, which were obtained by experiment and by simulation using DEFORM 3D V6.1. Samples of metal parts were subsequently fabricated by using hydraulic press machinery. In order to compare the influence of loading method, two types of samples were fabricated: (1) samples fabricated under direct loading die sets (2) those fabricated under indirect loading die sets. The formability and defects, which were predicted by FEM simulation, were similar to those of samples used in practice.

  17. Experimental and Numerical Investigation of Forging Process to Reproduce a 3D Aluminium Foam Complex Shape

    NASA Astrophysics Data System (ADS)

    Filice, Luigino; Gagliardi, Francesco; Shivpuri, Rajiv; Umbrello, Domenico

    2007-05-01

    Metallic foams represent one of the most exciting materials introduced in the manufacturing scenario in the last years. In the study here addressed, the experimental and numerical investigations on the forging process of a simple foam billet shaped into complex sculptured parts were carried out. In particular, the deformation behavior of metallic foams and the development of density gradients were investigated through a series of experimental forging tests in order to produce a selected portion of a hip prosthesis. The human bone replacement was chosen as case study due to its industrial demand and for its particular 3D complex shape. A finite element code (Deform 3D®) was utilized for modeling the foam behavior during the forging process and an accurate material rheology description was used based on a porous material model which includes the measured local density. Once the effectiveness of the utilized Finite Element model was verified through the comparison with the experimental evidences, a numerical study of the influence of the foam density was investigated. The obtained numerical results shown as the initial billet density plays an important role on the prediction of the final shape, the optimization of the flash as well as the estimation of the punch load.

  18. Weldability and mechanical property characterization of weld clad alloy 800H tubesheet forging

    SciTech Connect

    King, J.F.; McCoy, H.E.

    1984-09-01

    The weldability of an alloy 800H forging that simulates a steam generator tubesheet is studied. Weldability was of concern because a wide range of microstructures was present in this forging. The top and portions of the bottom were weld clad with ERNiC-3 weld metal to a thickness of 19 mm similar to that anticipated for HTGR steam generators. Examinations of the clad fusion line in various regions revealed no weldability problems except possibly on the bottom portion, which contained large grains and some as-cast structure. A few microfissures were evident in this region, but no excessive hot cracking tendency was observed. The tensile properties in all areas of the clad forging were reasonable and not influenced greatly by the microstructure. The elevated-temperature tests showed strong tendency for fracture in the heat-affected zone of the alloy 800H. Creep failure at 649/sup 0/C consistently occurred in the heat-affected zone of the alloy 800H, but the creep strength exceeded the expected values for alloy 800H.

  19. Lactobacillusassisted synthesis of titanium nanoparticles

    PubMed Central

    2007-01-01

    An eco-friendlylactobacillussp. (microbe) assisted synthesis of titanium nanoparticles is reported. The synthesis is performed at room temperature. X-ray and transmission electron microscopy analyses are performed to ascertain the formation of Ti nanoparticles. Individual nanoparticles as well as a number of aggregates almost spherical in shape having a size of 40–60 nm are found.

  20. PLUTONIUM-URANIUM-TITANIUM ALLOYS

    DOEpatents

    Coffinberry, A.S.

    1959-07-28

    A plutonium-uranium alloy suitable for use as the fuel element in a fast breeder reactor is described. The alloy contains from 15 to 60 at.% titanium with the remainder uranium and plutonium in a specific ratio, thereby limiting the undesirable zeta phase and rendering the alloy relatively resistant to corrosion and giving it the essential characteristic of good mechanical workability.

  1. Investigation of the Workability and Response of Ti-6Al-4V Titanium alloys at Lower Elevated Temperature and Higher Strain Rate

    SciTech Connect

    Huang, Cindy Xiaohui; Lim, Chao Voon; Castagne, Sylvie

    2011-05-04

    Titanium and its alloys have a wide range of applications in various industries such as aerospace, medical, automotive and even commercial products. However, formability of titanium alloys has always been an issue. This study presents the results of an investigation on the workability and response of Ti-6Al-4V deformed at different strain rates and lower elevated temperatures with different initial microstructures. Compression tests of cylindrical specimens were performed at various temperatures (300 deg. C, 400 deg. C, 450 deg. C, 500 deg. C) and at different strain rates (0.001 s{sup -1}, 0.02 s{sup -1} and 0.1 s{sup -1}). The effects of strain rate, temperature and initial microstructure on the workability of the Ti alloy were investigated. Based on these experimental results, workability maps for the respective initial microstructures were developed. Results showed that temperature played an important role in the formability of Ti-6Al-4V titanium alloys unlike strain rate. In addition, feasibility study on Multi-Directional Forging (MDF) was performed and positive results were obtained. It was demonstrated that Ti-6Al-4V titanium alloys can undergo severe plastic deformation at lower elevated temperature (400-500 deg. C) and at a higher strain rate of 0.1 s{sup -1}.

  2. Tensile properties of titanium electrolytically charged with hydrogen

    NASA Technical Reports Server (NTRS)

    Smith, R. J.; Otterson, D. A.

    1971-01-01

    Yield strength, ultimate tensile strength, and elongation were studied for annealed titanium electrolytically charged with hydrogen. The hydrogen was present as a surface hydride layer. These tensile properties were generally lower for uncharged titanium than for titanium with a continuous surface hydride; they were greater for uncharged titanium than for titanium with an assumed discontinuous surface hydride. We suggest that the interface between titanium and titanium hydride is weak. And the hydride does not necessarily impair strength and ductility of annealed titanium. The possibility that oxygen and/or nitrogen can embrittle titanium hydride is discussed.

  3. Mode III cleavage of a coin-shaped titanium implant in bone: effect of friction and crack propagation.

    PubMed

    Mathieu, Vincent; Vayron, Romain; Barthel, Etienne; Dalmas, Davy; Soffer, Emmanuel; Anagnostou, Fani; Haiat, Guillaume

    2012-04-01

    Endosseous cementless implants are widely used in orthopaedic, maxillofacial and oral surgery. However, failures are still observed and remain difficult to anticipate as remodelling phenomena at the bone-implant interface are poorly understood. The assessment of the biomechanical strength of the bone-implant interface may improve the understanding of the osseointegration process. An experimental approach based on a mode III cleavage mechanical device aims at understanding the behaviour of a planar bone-implant interface submitted to torsional loading. To do so, coin-shaped titanium implants were inserted on the tibiae of a New Zealand white rabbit for seven weeks. After the sacrifice, mode III cleavage experiments were performed on bone samples. An analytical model was developed to understand the debonding process of the bone-implant interface. The model allowed to assess the values of different parameters related to bone tissue at the vicinity of the implant with the additional assumption that bone adhesion occurs over around 70% of the implant surface, which is confirmed by microscopy images. The approach allows to estimate different quantities related to the bone-implant interface such as: torsional stiffness (around 20.5 N m rad(-1)), shear modulus (around 240 MPa), maximal torsional loading (around 0.056 N.m), mode III fracture energy (around 77.5 N m(-1)) and stress intensity factor (0.27 MPa m(1/2)). This study paves the way for the use of mode III cleavage testing for the investigation of torsional loading strength of the bone-implant interface, which might help for the development and optimization of implant biomaterial, surface treatment and medical treatment investigations.

  4. Radiostereometric Analysis Study of Tantalum Compared with Titanium Acetabular Cups and Highly Cross-Linked Compared with Conventional Liners in Young Patients Undergoing Total Hip Replacement

    PubMed Central

    Ayers, David C.; Greene, Meridith; Snyder, Benjamin; Aubin, Michelle; Drew, Jacob; Bragdon, Charles

    2015-01-01

    Background: Radiostereometric analysis provides highly precise measurements of component micromotion relative to the bone that is otherwise undetectable by routine radiographs. This study compared, at a minimum of five years following surgery, the micromotion of tantalum and titanium acetabular cups and femoral head penetration in highly cross-linked polyethylene liners and conventional (ultra-high molecular weight polyethylene) liners in active patients who had undergone total hip replacement. Methods: This institutional review board-approved prospective, randomized, blinded study involved forty-six patients. Patients were randomized into one of four cohorts according to both acetabular cup and polyethylene liner. Patients received either a cementless cup with a titanium mesh surface or a tantalum trabecular surface and either a highly cross-linked polyethylene liner or an ultra-high molecular weight polyethylene liner. Radiostereometric analysis examinations and Short Form-36 Physical Component Summary, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), University of California Los Angeles (UCLA) activity, and Harris hip scores were obtained preoperatively, postoperatively, at six months, and annually thereafter. Results: All patients had significant improvement (p < 0.05) in Short Form-36 Physical Component Summary, WOMAC, UCLA activity, and Harris hip scores postoperatively. On radiostereometric analysis examination, highly cross-linked polyethylene liners showed significantly less median femoral head penetration at five years (p < 0.05). Steady-state wear rates from one year to five years were 0.04 mm per year for ultra-high molecular weight polyethylene liners and 0.004 mm per year for highly cross-linked polyethylene liners. At the five-year follow-up, the median migration (and standard error) was 0.05 ± 0.20 mm proximally for titanium cups and 0.21 ± 0.05 mm for tantalum cups. Conclusions: In this young population who had undergone

  5. Titanium-Oxygen Reactivity Study

    NASA Technical Reports Server (NTRS)

    Chafey, J. E.; Scheck, W. G.; Witzell, W. E.

    1962-01-01

    A program has been conducted at Astronautics to investigate the likelihood of occurrence of the catastrophic oxidation of titanium alloy sheet under conditions which simulate certain cases of accidental failure of the metal while it is in contact with liquid or gaseous oxygen. Three methods of fracturing the metal were used; they consisted of mechanical puncture, tensile fracture of welded joints, and perforation by very high velocity particles. The results of the tests which have been conducted provide further evidence of the reactivity of titanium with liquid and gaseous oxygen. The evidence indicates that the rapid fracturing of titanium sheet while it is in contact with oxygen initiates the catastrophic oxidation reaction. Initiation occurred when the speed of the fracture was some few feet per second, as in both the drop-weight puncture tests and the static tensile fracture tests of welded joints, as well as when the speed was several thousand feet per second, as in the simulated micrometeoroid penetration tests. The slow propagation of a crack, however, did not initiate the reaction. It may logically be concluded that the localized frictional heat of rapid fracture and/or spontaneous oxidation (exothermic) of minute particles emanating from the fracture cause initiation of the reaction. Under conditions of slow fracture, however, the small heat generated may be adequately dissipated and the reaction is not initiated. A portion of the study conducted consisted of investigating various means by which the reaction might be retarded or prevented. Providing a "barrier" at the titanium-oxygen interface consisting of either aluminum metal or a coating of a petroleum base corrosion inhibitor appeared to be only partially effective in retarding the reaction. The accidental puncturing or similar rupturing of thin-walled pressurized oxygen tanks on missiles and space vehicle will usually constitute loss of function, and may sometimes cause their catastrophic destruction

  6. Antimicrobial titanium/silver PVD coatings on titanium

    PubMed Central

    Ewald, Andrea; Glückermann, Susanne K; Thull, Roger; Gbureck, Uwe

    2006-01-01

    Background Biofilm formation and deep infection of endoprostheses is a recurrent complication in implant surgery. Post-operative infections may be overcome by adjusting antimicrobial properties of the implant surface prior to implantation. In this work we described the development of an antimicrobial titanium/silver hard coating via the physical vapor deposition (PVD) process. Methods Coatings with a thickness of approximately 2 μm were deposited on titanium surfaces by simultaneous vaporisation of both metals in an inert argon atmosphere with a silver content of approximately 0.7 – 9% as indicated by energy dispersive X-ray analysis. On these surfaces microorganisms and eukaryotic culture cells were grown. Results The coatings released sufficient silver ions (0.5–2.3 ppb) when immersed in PBS and showed significant antimicrobial potency against Staphylococcus epidermis and Klebsiella pneumoniae strains. At the same time, no cytotoxic effects of the coatings on osteoblast and epithelial cells were found. Conclusion Due to similar mechanical performance when compared to pure titanium, the TiAg coatings should be suitable to provide antimicrobial activity on load-bearing implant surfaces. PMID:16556327

  7. Formation of crystalline titanium(IV) phosphates from titanium(III) solutions

    SciTech Connect

    Bortun, A.; Jaimez, E.; Llavona, R.; Garcia, J.R.; Rodriguez, J.

    1995-04-01

    Crystalline phases of titanium (IV) phosphate have been obtained from titanium(III) chloride in phosphoric acid solutions. The {alpha}-titanium phosphate synthesis is possible at low temperature (60--80 C). {gamma}-Titanium phosphate is obtained by reflux with very concentrated phosphoric acid in 3--5 hours by oxidation with O{sub 2}. The influence in these reactions of several factors (concentration of reagents, molar ratio P:Ti in the reaction mixture, temperature and reaction) was studied. The {alpha}-titanium phosphate formation takes place in several steps through the sequential formation of amorphous titanium(IV) phosphate, {gamma}-titanium phosphate and/or a semicrystalline titanium(IV) hydroxophosphate, Ti(OH){sub 2}(HPO{sub 4}){center_dot}H{sub 2}O.

  8. 40 CFR 721.10602 - Lead niobium titanium zirconium oxide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... the following substances: Lead strontium titanium zirconium oxide (PMN P-11-270; CAS No. 61461-40-3... strontium titanium tungsten oxide (PMN P-11-272; CAS No. 1262279-30-0); Lanthanum lead titanium...

  9. 40 CFR 721.10602 - Lead niobium titanium zirconium oxide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... the following substances: Lead strontium titanium zirconium oxide (PMN P-11-270; CAS No. 61461-40-3... strontium titanium tungsten oxide (PMN P-11-272; CAS No. 1262279-30-0); Lanthanum lead titanium...

  10. Superplastic Forming of Titanium Structures

    DTIC Science & Technology

    1975-04-01

    configurations. These configurations included rectangular and circular pan sections, stepped side walls, beads, joggles , and multiple parts formed at one...capability of being formed to a complex configuration with well-formed beads and Joggles , tight bend radii, and 90-degree return flanges. Since titanium...Coming operation. The configuration consists of joggles and steps positioned into the basic forming box to produce a four-cavity tool symmetrical about

  11. Free Form Low Cost Fabrication Using Titanium

    DTIC Science & Technology

    2007-06-29

    nickel-base superalloys . "* The tensile strength as an alloy of titanium can be comparable to that of lower-strength marterisitic stainless and is...better than that of austenitic or ferritic stainless. Alloys can have ultimate strengths comparable to iron base superalloys , such as A286, or cobalt...dependent on composition. Some alloy systems (titanium aluminides ) may have useful strengths above this temperature. "* The cost of titanium, while

  12. Production of titanium from ilmenite: a review

    SciTech Connect

    Kohli, R.

    1981-12-01

    The general principles for beneficiation of titanium ores are reviewed and the specific processes used in individual units in various countries are discussed. This is followed by a critical evaluation of various current and potential reduction methods for the production of titanium metal from the processed concentrates. Finally, the report outlines a research program for the development of a commercially viable alternative method for the production of titanium metal.

  13. Ultrafine-grained titanium for medical implants

    DOEpatents

    Zhu, Yuntian T.; Lowe, Terry C.; Valiev, Ruslan Z.; Stolyarov, Vladimir V.; Latysh, Vladimir V.; Raab, Georgy J.

    2002-01-01

    We disclose ultrafine-grained titanium. A coarse-grained titanium billet is subjected to multiple extrusions through a preheated equal channel angular extrusion (ECAE) die, with billet rotation between subsequent extrusions. The resulting billet is cold processed by cold rolling and/or cold extrusion, with optional annealing. The resulting ultrafine-grained titanium has greatly improved mechanical properties and is used to make medical implants.

  14. Recovery of titanium values from titanium grinding swarf by electric furnace smelting

    SciTech Connect

    Gerdemann, S.J.; White, J.C.

    1999-10-19

    A method for the recovery of valuable materials from titanium grinding swarf is provided comprising the steps of sieving the accumulated titanium grinding swarf to remove unwanted coarse trash and grinding wheel fragments, pelletizing, and smelting in an electric arc furnace to produce ferrotitanium and/or high titanium slag.

  15. Recovery of titanium values from titanium grinding swarf by electric furnace smelting

    DOEpatents

    Gerdemann, Stephen J.; White, Jack C.

    1998-01-01

    A method for the recovery of valuable materials from titanium grinding swarf is provided comprising the steps of sieving the accumulated titanium grinding swarf to remove unwanted coarse trash and grinding wheel fragments, pelletizing, and smelting in an electric arc furnace to produce ferrotitanium and/or high titanium slag.

  16. Recovery of titanium values from titanium grinding swarf by electric furnace smelting

    DOEpatents

    Gerdemann, Stephen J.; White, Jack C.

    1999-01-01

    A method for the recovery of valuable materials from titanium grinding swarf is provided comprising the steps of sieving the accumulated titanium grinding swarf to remove unwanted coarse trash and grinding wheel fragments, pelletizing, and smelting in an electric arc furnace to produce ferrotitanium and/or high titanium slag.

  17. Recovery of titanium values from titanium grinding swarf by electric furnace smelting

    DOEpatents

    Gerdemann, S.J.; White, J.C.

    1998-08-04

    A method for the recovery of valuable materials from titanium grinding swarf is provided comprising the steps of sieving the accumulated titanium grinding swarf to remove unwanted coarse trash and grinding wheel fragments, pelletizing, and smelting in an electric arc furnace to produce ferrotitanium and/or high titanium slag. 1 fig.

  18. Reduction of titanium dioxide to metallic titanium conducted under the autogenic pressure of the reactants.

    PubMed

    Eshed, Michal; Irzh, Alexander; Gedanken, Aharon

    2009-08-03

    We report on a reaction to convert titanium dioxide to titanium. The reduction reaction was done under the autogenic pressure of the reactants at 750 degrees C for 5 h. The MgO, a by-product, was removed by acids to obtain pure metallic titanium.

  19. Influence of die geometry and material selection on the behavior of protective die covers in closed-die forging

    NASA Astrophysics Data System (ADS)

    Yu, Yingyan; Rosenstock, Dirk; Wolfgarten, Martin; Hirt, Gerhard

    2016-10-01

    Due to the fact that tooling costs make up to 30% of total costs of the final forged part, the tool life is always one main research topic in closed-die forging [1]. To improve the wear resistance of forging dies, many methods like nitriding and deposition of ceramic layers have been used. However, all these methods will lose its effect after a certain time, then tool repair or exchange is needed, which requires additional time and costs. A new method, which applies an inexpensive and changeable sheet metal on the forging die to protect it from abrasive wear, was firstly proposed in [2]. According to the first investigation, the die cover is effective for decreasing thermal and mechanical loads, but there are still several challenges to overcome in this concept, like wrinkling and thinning of the die cover. Therefore, an experimental study using different geometries and die cover materials is presented within this work. The results indicate the existence of feasible application cases of this concept, since conditions are found under which a die cover made of 22MnB5 still keeps its original shape even after 7 forging cycles.

  20. Computer-Aided Design of Manufacturing Chain Based on Closed Die Forging for Hardly Deformable Cu-Based Alloys

    NASA Astrophysics Data System (ADS)

    Pietrzyk, Maciej; Kuziak, Roman; Pidvysots'kyy, Valeriy; Nowak, Jarosław; Węglarczyk, Stanisław; Drozdowski, Krzysztof

    2013-07-01

    Two copper-based alloys were considered, Cu-1 pct Cr and Cu-0.7 pct Cr-1 pct Si-2 pct Ni. The thermal, electrical, and mechanical properties of these alloys are given in the paper and compared to pure copper and steel. The role of aging and precipitation kinetics in hardening of the alloys is discussed based upon the developed model. Results of plastometric tests performed at various temperatures and various strain rates are presented. The effect of the initial microstructure on the flow stress was investigated. Rheologic models for the alloys were developed. A finite element (FE) model based on the Norton-Hoff visco-plastic flow rule was applied to the simulation of forging of the alloys. Analysis of the die wear for various processes of hot and cold forging is presented as well. A microstructure evolution model was implemented into the FE code, and the microstructure and mechanical properties of final products were predicted. Various variants of the manufacturing cycles were considered. These include different preheating schedules, hot forging, cold forging, and aging. All variants were simulated using the FE method and loads, die filling, tool wear, and mechanical properties of products were predicted. Three variants giving the best combination of forging parameters were selected and industrial trials were performed. The best manufacturing technology for the copper-based alloys is proposed.

  1. Effect of forging parameters on low cycle fatigue behaviour of Al/basalt short fiber metal matrix composites.

    PubMed

    Karthigeyan, R; Ranganath, G

    2013-01-01

    This paper deals with metal matrix composites (MMCs) of Al 7075 alloy containing different weight percentage (2.5, 5, 7.5, and 10) basalt short fiber reinforcement and unreinforced matrix alloy. The samples were produced by the permanent stir casting technique. The casting ingots were cut into blanks to be forged in single stage and double stage, using MN press and graphite-based lubricant. The microstructures and fatigue properties of the matrix alloy and MMC samples were investigated in the as cast state and in the single and double stage forging operations. The microstructure results showed that the forged sample had a uniform distribution of the basalt short fiber throughout the specimens. Evaluation of the fatigue properties showed that the forged samples had higher values than those of the as cast counterparts. After forging, the enhancement of the fatigue strength of the matrix alloy was so significant and high in the case of 2.5 and 5.0 wt. percentage basalt short fiber reinforced MMC, and there was no enhancement in 7.5 and 10 weight percentages short fiber reinforced MMCs. The fracture damage was mainly due to decohesion at the matrix-fiber interface.

  2. Effects of Low Temperature on Hydrogen-Assisted Crack Growth in Forged 304L Austenitic Stainless Steel

    NASA Astrophysics Data System (ADS)

    Jackson, Heather; San Marchi, Chris; Balch, Dorian; Somerday, Brian; Michael, Joseph

    2016-08-01

    The objective of this study was to evaluate effects of low temperature on hydrogen-assisted crack propagation in forged 304L austenitic stainless steel. Fracture initiation toughness and crack-growth resistance curves were measured using fracture mechanics specimens that were thermally precharged with 140 wppm hydrogen and tested at 293 K or 223 K (20 °C or -50 °C). Fracture initiation toughness for hydrogen-precharged forgings decreased by at least 50 to 80 pct relative to non-charged forgings. With hydrogen, low-temperature fracture initiation toughness decreased by 35 to 50 pct relative to room-temperature toughness. Crack growth without hydrogen at both temperatures was microstructure-independent and indistinguishable from blunting, while with hydrogen microcracks formed by growth and coalescence of microvoids. Initiation of microvoids in the presence of hydrogen occurred where localized deformation bands intersected grain boundaries and other deformation bands. Low temperature additionally promoted fracture initiation at annealing twin boundaries in the presence of hydrogen, which competed with deformation band intersections and grain boundaries as sites of microvoid formation and fracture initiation. A common ingredient for fracture initiation was stress concentration that arose from the intersection of deformation bands with these microstructural obstacles. The localized deformation responsible for producing stress concentrations at obstacles was intensified by low temperature and hydrogen. Crack orientation and forging strength were found to have a minor effect on fracture initiation toughness of hydrogen-supersaturated 304L forgings.

  3. Effect of Forging Parameters on Low Cycle Fatigue Behaviour of Al/Basalt Short Fiber Metal Matrix Composites

    PubMed Central

    Karthigeyan, R.; Ranganath, G.

    2013-01-01

    This paper deals with metal matrix composites (MMCs) of Al 7075 alloy containing different weight percentage (2.5, 5, 7.5, and 10) basalt short fiber reinforcement and unreinforced matrix alloy. The samples were produced by the permanent stir casting technique. The casting ingots were cut into blanks to be forged in single stage and double stage, using MN press and graphite-based lubricant. The microstructures and fatigue properties of the matrix alloy and MMC samples were investigated in the as cast state and in the single and double stage forging operations. The microstructure results showed that the forged sample had a uniform distribution of the basalt short fiber throughout the specimens. Evaluation of the fatigue properties showed that the forged samples had higher values than those of the as cast counterparts. After forging, the enhancement of the fatigue strength of the matrix alloy was so significant and high in the case of 2.5 and 5.0 wt. percentage basalt short fiber reinforced MMC, and there was no enhancement in 7.5 and 10 weight percentages short fiber reinforced MMCs. The fracture damage was mainly due to decohesion at the matrix-fiber interface. PMID:24298207

  4. Visible Spectra of Titanium Dioxide

    NASA Astrophysics Data System (ADS)

    Gupta, V.; Nagarajan, R.; Maier, J. P.; Zhuang, X.; Le, A.; Steimle, T. C.

    2011-05-01

    Titanium oxide (TiO) has been extensively studied spectroscopically due to its astrophysical relevance. TiO is the main opacity source in the atmospheres of cool M-type stars in the visible and near infrared. In view of the high cosmic abundance of Ti and O, titanium dioxide (TiO2) is believed to play an important role in dust formation processes from the gas-phase in circumstellar shells of oxygen-rich stars. The electronic spectra of a cold molecular beam of TiO2 have been investigated using mass-resolved resonance enhanced multi-photon ionization and laser induced fluorescence spectroscopy. TiO2 was produced by laser ablation of a pure titanium rod in the presence of a supersonic expanding mixture of approximately 5% O2 in either helium or argon. The spectra were recorded in the region 17500 cm-1 to 22500 cm-1 and the bands assigned to the A1B2 ← X1A1 transition. The origin and harmonic vibrational constants for the A1B2 state were determined to be: T000 = 17593(5) cm-1, ω1 = 876(3) cm-1, ω2 = 184(1) cm-1, and ω3 = 316(2) cm-1. Further, the dispersed fluorescence of a few bands were recorded to obtain vibrational parameters for the X1A1 state.

  5. Welded Permanent Fittings for Titanium Hydraulic Tubing.

    DTIC Science & Technology

    FITTINGS, *HYDRAULIC EQUIPMENT, RIVETED JOINTS, TITANIUM ALLOYS, PIPES , JET TRANSPORT AIRCRAFT, COLD WORKING, PRESSURE, RUPTURE, ARC WELDING , INERT...GAS WELDING , RADIOGRAPHY, STRESS RELIEVING, SUPERSONIC AIRCRAFT, COMMERCIAL AIRCRAFT.

  6. Method for producing titanium aluminide weld rod

    DOEpatents

    Hansen, Jeffrey S.; Turner, Paul C.; Argetsinger, Edward R.

    1995-01-01

    A process for producing titanium aluminide weld rod comprising: attaching one end of a metal tube to a vacuum line; placing a means between said vacuum line and a junction of the metal tube to prevent powder from entering the vacuum line; inducing a vacuum within the tube; placing a mixture of titanium and aluminum powder in the tube and employing means to impact the powder in the tube to a filled tube; heating the tube in the vacuum at a temperature sufficient to initiate a high-temperature synthesis (SHS) reaction between the titanium and aluminum; and lowering the temperature to ambient temperature to obtain a intermetallic titanium aluminide alloy weld rod.

  7. Forging of eccentric co-extruded Al-Mg compounds and analysis of the interface strength

    NASA Astrophysics Data System (ADS)

    Förster, W.; Binotsch, C.; Awiszus, B.; Lehmann, T.; Müller, J.; Kirbach, C.; Stockmann, M.; Ihlemann, J.

    2016-03-01

    Within the subproject B3 of the Collaborative Research Center 692 it has been shown that Al-Mg compounds with a good bonding quality can be produced by hydrostatic coextrusion. During processing by forging, the aluminum sleeve is thinned in areas of high strains depending on the component geometry. To solve this problem an eccentric core arrangement during co-extrusion was investigated. Based on the results of FE-simulations, the experimental validation is presented in this work. Rods with an offset of 0.25, 0.5 and 0.75 mm were produced by eccentric hydrostatic co-extrusion. Ultrasonic testing was used to evaluate the bonding quality across the entire rods. For the forging investigations the basic process Rising was chosen. The still good bonding quality after forging was examined by dye penetrant testing and optical microscopy. For an optimal stress transfer between the materials across the entire component, a sufficient bonding between the materials is essential. To evaluate the interface strength, a special bending test was developed. For the conception of the bending specimens it was required to analyze the Rising specimens geometry. These analyses were performed using a reconstruction of the geometrical data based on computer tomography (CT) investigations. The comparison with the numerically deter-mined Rising specimen geometry shows good correlation. Parametric Finite Element Analyses of the bending test were used to develop the load case and the specimen geometry. By means of iterative adaption of load application, bearing and specimen geometry parameters, an advantageous stress state and experimentally applicable configuration were found. Based on this conception, the experimental setup was configured and bending tests were performed. The interface strength was deter-mined by the calculation of the maximum interlaminar interfacial tension stress using the experimental interface failure force and the bending FE model.

  8. Hot forging of melt quenched powder: Microstructure development and kinetics of densification

    NASA Astrophysics Data System (ADS)

    Keshavan, Hrishikesh

    Hot powder forging is a new process for making scalable and cost-effective nanocrystalline ceramics. It utilizes powder typically between 5 mum to 25 mum to nucleate very stable crystallite sizes well below 100 nm. These particles superplastically deform at relatively moderate temperature and stress. Hence, rapid densification at high creep rates is achieved with limited grain growth. A novel way to achieve high creep rate is to take advantage of partially amorphous powders that are obtained by one of the many available rapid quenching processes. Our study uses a plasma flame to melt the spray-dried aggregates of a particular composition and rapidly quench into water that results in metastable, optically transparent powder. The plasma sprayed powder is first hot pressed to obtain cylindrical pellets and then hot-forged at various stresses and temperatures to obtain optimum creep rates. Eutectic oxide compositions were studied due to their low melting point and better glass forming ability in an effort to optimize both the composition and processing parameters. Five binary compositions of alumina, zirconia and magnesium aluminate spinel and the effect of adding borosilicate glass on creep rates and microstructure were investigated. Their phase evolution and crystallite growth were examined in a detailed annealing study. The final densities after hot forging were composition dependent and ranged from 86% to 100% at 1350°C. Creep rates of the binary eutectic increased by an order of magnitude when alumina was substituted with spinel or when borosilicate glass was added. The highest creep rate obtained would correspond to 10-4 1/s for 40 MPa at 1350°C. SEM studies confirm that the densification is by plastic deformation of particles. TEM studies reveal nano-sized zirconia either in an alumina or spinel matrix. The grain morphology was cellular in compositions without glass and acicular in compositions with glass.

  9. High Temperature, Slow Strain Rate Forging of Advanced Disk Alloy ME3

    NASA Technical Reports Server (NTRS)

    Gabb, Timothy P.; OConnor, Kenneth

    2001-01-01

    The advanced disk alloy ME3 was designed in the HSR/EPM disk program to have extended durability at 1150 to 1250 F in large disks. This was achieved by designing a disk alloy and process producing balanced monotonic, cyclic, and time-dependent mechanical properties. combined with robust processing and manufacturing characteristics. The resulting baseline alloy, processing, and supersolvus heat treatment produces a uniform, relatively fine mean grain size of about ASTM 7, with as-large-as (ALA) grain size of about ASTM 3. There is a long term need for disks with higher rim temperature capabilities than 1250 F. This would allow higher compressor exit (T3) temperatures and allow the full utilization of advanced combustor and airfoil concepts under development. Several approaches are being studied that modify the processing and chemistry of ME3, to possibly improve high temperature properties. Promising approaches would be applied to subscale material, for screening the resulting mechanical properties at these high temperatures. n obvious path traditionally employed to improve the high temperature and time-dependent capabilities of disk alloys is to coarsen the grain size. A coarser grain size than ASTM 7 could potentially be achieved by varying the forging conditions and supersolvus heat treatment. The objective of this study was to perform forging and heat treatment experiments ("thermomechanical processing experiments") on small compression test specimens of the baseline ME3 composition, to identify a viable forging process allowing significantly coarser grain size targeted at ASTM 3-5, than that of the baseline, ASTM 7.

  10. Derivation of uranium residual radioactive material guidelines for the Aliquippa Forge site

    SciTech Connect

    Monette, F.; Jones, L.; Yu, C.

    1992-09-01

    Residual radioactive material guidelines for uranium were derived for the Aliquippa Forge site in Aliquippa, Pennsylvania. This site has been identified for remedial action under the Formerly Utilized Sites Remedial Action Program (FUSRAP) of the US Department of Energy (DOE). The uranium guidelines were derived on the basis of the requirement that the 50-year committed effective dose equivalent to a hypothetical individual who lives or works in the immediate vicinity of the Aliquippa Forge site should not exceed a dose of 100 mrem/yr following decontamination. The DOE residual radioactive material guideline computer code, RESRAD, which implements the methodology described in the DOE manual for implementing residual radioactive material guidelines, was used in this evaluation. Four potential scenarios were considered for the site; the scenarios vary with regard to time spent at the site, sources of water used, and sources of food consumed. The results of the evaluation indicate that the basic dose limit of 100 mrem/yr will not be exceeded for uranium within 1,000 years, provided that the soil concentration of combined uranium (uranium-234, uranium-235, and uranium-238) at the Aliquippa Forge site does not exceed the following levels: 1,700 pCi/g for Scenario A (industrial worker: the expected scenario); 3,900 pCi/g for Scenario B (recreationist: a plausible scenario); 20 pCi/g for Scenario C (resident farmer using well water as the only water source: a possible but unlikely scenario), and 530 pCi/g for Scenario D (resident farmer using a distant water source not affected by site conditions as the only water source: a possible but unlikely scenario). The uranium guidelines derived in this report apply to the combined activity concentration of uranium-234, uranium-235, and uranium-238 and were calculated on the basis of a dose of 100 mrem/yr.

  11. Validation of finite-element codes for prediction of machining distortions in forgings

    NASA Astrophysics Data System (ADS)

    Chandra, U.

    1993-06-01

    When a forging is machined to its net shape, unacceptably large distortions can occur if the final part shape is complex. Such distortions can be predicted with the application of the finite-element method. However, numerical errors associated with the finite element technique can render such predictions unreliable. This paper presents benchmark problems for verifying the accuracy of machining distortions predicted by any prospective finite-element code. Also, a comparison between two industry-standard general-purpose codes, ANSYS and ABAQUS, is presented.

  12. A Metallurgical Investigation of Large Forged Discs of Low-carbon N-155 Alloy

    NASA Technical Reports Server (NTRS)

    Cross, Howard C; Freeman, J W

    1947-01-01

    Research was undertaken to ascertain the properties of better wrought heat resisting alloys in the form of large discs required for gas turbine rotors. The properties of large discs of low carbon N-155 alloy in both the as-forged and water-quenched and aged conditions were determined by means of stress-rupture and creep tests for time periods up to about 2000 hours at 1200, 1350, and 1500 F. Short-time tensile test, impact test, and time-total deformation characteristics are included. The principle results are given.

  13. Military Specification for Type 10XX Powder-Forged Weapon Components.

    DTIC Science & Technology

    1985-10-14

    6292-3 UNLSIFIED RRSCO- CR -50 ORRKICI-4-C-0245 F/G 11/6.2 2 I ihhhEhh irmmohhmhmhum I, 111112.2 I1.25 1 . 51IM NIII qp 4 I.~ - . 1 3 N OV 1985...CONTRACTOR REPORT ARSCD- CR -85008 !MILITARY SPECIFICATION FOR TYPE IOXX : POWDER-FORGED WEAPON COMPONENTS - .I-. - 5 ~FINAL TECHNICAL REPORT [ -- STEVEN...INSTRUCTiONS R R O iEEFORE COMPLETING FORM I. REPORT NUMBER 2. GOVT ACCESSION NQ. " E CiPIENT’. CATALOU NUMBLR Contractor Report ARSCD- CR -85008 4- TITLE (a"nd

  14. Forging a poison prevention and control system: report of an Institute of Medicine committee.

    PubMed

    Guyer, Bernard; Mavor, Anne

    2005-01-01

    The Committee forged a vision for a national poison prevention and control system that broadly integrates the current network of poison control centers with state and local public health departments responsible for monitoring populations. Implementing the Committee's recommendations, however, will require leadership from the Congress and the federal agencies to whom the report is addressed: HRSA and CDC. The next steps include amendments to existing legislation to establish the national system and to secure federal funding to assure stability of the system and systematic oversight by the federal agencies to hold all parties accountable for the performance of the system.

  15. Conventionally cast and forged copper alloy for high-heat-flux thrust chambers

    NASA Technical Reports Server (NTRS)

    Kazaroff, John M.; Repas, George A.

    1987-01-01

    The combustion chamber liner of the space shuttle main engine is made of NARloy-Z, a copper-silver-zirconium alloy. This alloy was produced by vacuum melting and vacuum centrifugal casting; a production method that is currently now available. Using conventional melting, casting, and forging methods, NASA has produced an alloy of the same composition called NASA-Z. This report compares the composition, microstructure, tensile properties, low-cycle fatigue life, and hot-firing life of these two materials. The results show that the materials have similar characteristics.

  16. A hot compression testing apparatus for the study of isothermal forging

    NASA Astrophysics Data System (ADS)

    Immarigeon, J.-P. A.; Wallace, W.; Iandeil, A. Y.; de Malherbe, M. C.

    1980-11-01

    An apparatus for uniaxial compression testing has been developed to simulate isothermal forging conditions. The system can apply 100-kN loads at temperatures up to 1200 + or - 3 C in a controlled environment and at constant true strain rates between 0.00001/s and 1/s. Results on the flow behavior of nickel-base superalloy compacts and composites are presented that demonstrate the importance of control of the testing parameters. The difference in flow strength of the two materials under identical testing conditions is discussed.

  17. Prediction of microstructure evolution during high temperature blade forging of a Ni-Fe based superalloy, Alloy 718

    NASA Astrophysics Data System (ADS)

    Na, Young-Sang; Yeom, Jong-Taek; Park, Nho-Kwang; Lee, Jai-Young

    2003-02-01

    The mechanical properties of the Ni-Fe-based Alloy 718 depend very much on grain size, as well as the strengthening phases, γ' and γ. The grain structure of the superalloy components is mainly controlled during thermo-mechanical processes by the dynamic, meta-dynamic recrystallization and grain growth. In this investigation, the evolution of the grain structure in the process of two-step blade forging was experimentally and numerically dealt with. The evolution of the grain structure in Alloy 718 during blade forging was predicted using a 2-DFE simulator with implemented constitutive models on dynamic recrystallization and grain growth. The comparison of the simulated microstructure with the actual grain structure of the forged parts validated the prediction of the grain structure evolution. The effect of dynamic recrystallization on the evolution of grain structure is highlighted in this article.

  18. Composite thin-foil bandpass filter for EUV astronomy Titanium-antimony-titanium

    NASA Technical Reports Server (NTRS)

    Jelinsky, P.; Martin, C.; Kimble, R.; Bowyer, S.; Steele, G.

    1983-01-01

    Thin metallic foils of antimony and titanium have been investigated in an attempt to develop an EUV filter with a bandpass from 350 to 550 A. A composite filter has been developed composed of antimony sandwiched between two titanium foils. The transmissions of sample composite foils and of pure titanium foils from 130 to 1216 A are presented. The absorption coefficients of anatimony and titanium and the effect of titanium oxide on the transmission are derived. The composite filter has been found to be quite stable and mechanically rugged. Among other uses, the filter shows substantial promise for EUV astronomy.

  19. Tribological evaluation of diamond coating on pure titanium in comparison with plasma nitrided titanium and uncoated titanium

    SciTech Connect

    Yan, B.; Loh, N.L.; Fu, Y.; Sun, C.Q.; Hing, P.

    1999-12-01

    Titanium alloys are characterized by poor tribological properties, and the traditional use of titanium alloys has been restricted to nontribological applications. The deposition of a well adherent diamond coating is a promising way to solve this problem. In this study, the tribological properties of diamond-coated titanium were studied using a pin-on-disk tribometer, and the results were compared with those of pure titanium and plasma nitrided titanium. The tribological behavior of pure titanium was characterized by high coefficient of friction and rapid wear of materials. Plasma nitriding improved the wear resistance only under low normal load; however, this hardened layer was not efficient in improving the wear resistance and the friction properties under high normal load. Diamond coating on pure titanium improved the wear resistance of titanium significantly. Surface profilometry measurement indicated that little or no wear of the diamond coating occurred under the test conditions loads. The roughness of the diamond coating was critical because it controlled the amount of abrasive damage on the counterface. Reducing the surface roughness by polishing led to the reductions in both the friction and wear of the counterface.

  20. Bonding titanium to Rene 41 alloy

    NASA Technical Reports Server (NTRS)

    Scott, R. W.

    1972-01-01

    Pair of intermediate materials joined by electron beam welding method welds titanium to Rene 41 alloy. Bond is necessary for combining into one structure high strength-to-density ratio titanium fan blades and temperature resistant nickel-base alloy turbine-buckets in VTOL aircraft lift-fan rotor.

  1. Fungal leaching of titanium from rock.

    NASA Technical Reports Server (NTRS)

    Silverman, M. P.; Munoz, E. F.

    1971-01-01

    Penicillium simplicissimum is found to solubilize up to 80% of the titanium in granitic rocks but less than 2% of the titanium in basaltic rocks. These findings were made in investigating the interactions of microorganisms with rocks and minerals of the biosphere in studies aimed at developing experiments for the detection of extraterrestrial life.

  2. 21 CFR 73.575 - Titanium dioxide.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... additive mixtures for food use made with titanium dioxide may contain only those diluents that are suitable and that are listed in this subpart as safe in color additive mixtures for coloring foods, and the... solution obtained by boiling 10 grams of the titanium dioxide for 15 minutes in 50 milliliters of...

  3. Titanium Carbide Bipolar Plate for Electrochemical Devices

    SciTech Connect

    LaConti, Anthony B.; Griffith, Arthur E.; Cropley, Cecelia C.; Kosek, John A.

    1998-05-08

    Titanium carbide comprises a corrosion resistant, electrically conductive, non-porous bipolar plate for use in an electrochemical device. The process involves blending titanium carbide powder with a suitable binder material, and molding the mixture, at an elevated temperature and pressure.

  4. High-niobium titanium aluminide alloys

    SciTech Connect

    Huang, S.C.

    1992-02-18

    This patent describes an aged niobium modified titanium aluminum alloy, the alloy consisting essentially of titanium, aluminum, and niobium in the following atomic ratio: Ti{sub 48-37}Al{sub 46-49}Nb{sub 6-14}, the alloy having been prepared by ingot metallurgy.

  5. Titanium carbide bipolar plate for electrochemical devices

    DOEpatents

    LaConti, Anthony B.; Griffith, Arthur E.; Cropley, Cecelia C.; Kosek, John A.

    2000-07-04

    A corrosion resistant, electrically conductive, non-porous bipolar plate is made from titanium carbide for use in an eletrochemical device. The process involves blending titanium carbide powder with a suitable binder material, and molding the mixture, at an elevated temperature and pressure.

  6. Gold-nickel-titanium brazing alloy

    DOEpatents

    Mizuhara, Howard

    1990-07-03

    A brazing alloy in accordance with this invention has the following composition, by weight: 91 to 99% gold, 0.5 to 7% nickel; 0.10 to 2% titanium. Alternatively, with palladium present, the composition is as follows, by weight: 83 to 96% gold; 3 to 10% palladium; 0.5 to 5% nickel; 0.10 to 2% titanium.

  7. Wettability studies of topologically distinct titanium surfaces.

    PubMed

    Kulkarni, Mukta; Patil-Sen, Yogita; Junkar, Ita; Kulkarni, Chandrashekhar V; Lorenzetti, Martina; Iglič, Aleš

    2015-05-01

    Biomedical implants made of titanium-based materials are expected to have certain essential features including high bone-to-implant contact and optimum osteointegration, which are often influenced by the surface topography and physicochemical properties of titanium surfaces. The surface structure in the nanoscale regime is presumed to alter/facilitate the protein binding, cell adhesion and proliferation, thereby reducing post-operative complications with increased lifespan of biomedical implants. The novelty of our TiO2 nanostructures lies mainly in the high level control over their morphology and roughness by mere compositional change and optimisation of the experimental parameters. The present work focuses on the wetting behaviour of various nanostructured titanium surfaces towards water. Kinetics of contact area of water droplet on macroscopically flat, nanoporous and nanotubular titanium surface topologies was monitored under similar evaporation conditions. The contact area of the water droplet on hydrophobic titanium planar surface (foil) was found to decrease during evaporation, whereas the contact area of the droplet on hydrophobic nanorough titanium surfaces practically remained unaffected until the complete evaporation. This demonstrates that the surface morphology and roughness at the nanoscale level substantially affect the titanium dioxide surface-water droplet interaction, opposing to previous observations for microscale structured surfaces. The difference in surface topographic nanofeatures of nanostructured titanium surfaces could be correlated not only with the time-dependency of the contact area, but also with time-dependency of the contact angle and electrochemical properties of these surfaces.

  8. Mineral resource of the month: titanium

    USGS Publications Warehouse

    Gambogi, Joseph

    2011-01-01

    Titanium is hip - at least when it comes to airplanes and jewelry. Known for its high strength-to weight ratio and its resistance to corrosion, titanium and its alloys can also be found in everything from knee replacements to eyeglass frames to baseball bats to fighter planes.

  9. Gold-nickel-titanium brazing alloy

    DOEpatents

    Mizuhara, Howard

    1995-01-03

    A brazing alloy in accordance with this invention has the following composition, by weight: 91 to 99 gold, 0.5 to 7% nickel; 0.10 to 2% titanium. Alternatively, with palladium present, the composition is as follows, by weight: 83 to 96% gold; 3 to 10% palladium; 0.5 to 5% nickel; 0.10 to 2% titanium.

  10. Forging tool shape optimization using pseudo inverse approach and adaptive incremental approach

    NASA Astrophysics Data System (ADS)

    Halouani, A.; Meng, F. J.; Li, Y. M.; Labergère, C.; Abbès, B.; Lafon, P.; Guo, Y. Q.

    2013-05-01

    This paper presents a simplified finite element method called "Pseudo Inverse Approach" (PIA) for tool shape design and optimization in multi-step cold forging processes. The approach is based on the knowledge of the final part shape. Some intermediate configurations are introduced and corrected by using a free surface method to consider the deformation paths without contact treatment. A robust direct algorithm of plasticity is implemented by using the equivalent stress notion and tensile curve. Numerical tests have shown that the PIA is very fast compared to the incremental approach. The PIA is used in an optimization procedure to automatically design the shapes of the preform tools. Our objective is to find the optimal preforms which minimize the equivalent plastic strain and punch force. The preform shapes are defined by B-Spline curves. A simulated annealing algorithm is adopted for the optimization procedure. The forging results obtained by the PIA are compared to those obtained by the incremental approach to show the efficiency and accuracy of the PIA.

  11. [Effects of peak levels and number of noise impulses on hearing among forge hammering workers].

    PubMed

    Suvorov, G A; Denisov, E I; Antipin, V G; Kharitonov, V I; Starck, Iu; Pyykko, I; Toppila, E

    2002-01-01

    The work was aimed (1) to compare actual and expected values of hearing loss in forge hammering workers, using risk evaluation patterns based on impulse noise measurements, and (2) to simulate harmful hearing changes caused by impulse noise. Study of exposure to noise and hearing loss covered forge hammering workers in 2 major blacksmith workshops of automobile enterprise, where equivalent levels of acoustic pressure (104 and 106 dB) were equal, but peak levels and impalse degrees reliably differed. Hearing thresholds for 2 selected groups of workers (97 and 235 subjects) were evaluated. When compared, actual and expected values of hearing loss calculated according to ISO standard appeared different with excess of 1 dB and 3 dB for the workers in shops 1 and 2 respectively. Excessive hearing loss corresponds to noise exposure increased by 3.5 years. Hearing loss in the workers subjected to less impulsive noise were readily forecasted by ISO standard 1999-1990. Hearing loss in the workers subjected to more impulsive noise were in reliable correlation with combination of peak level and impulses number.

  12. Study on Pot Forming of Induction Heater Type Rice Cookers by Forging Cast Process

    NASA Astrophysics Data System (ADS)

    Ohnishi, Masayuki; Yamaguchi, Mitsugi; Ohashi, Osamu

    This paper describes a study result on pot fabrication by the forging cast process of stainless steel with aluminum. Rice cooked with the new bowl-shaped pot for the induction heater type rice cookers is better tasting than rice cooked with the conventional cylindrical one, due to the achievement of better heat conduction and convection. The conventional pot is made of the clad sheet, consisting of stainless steel and aluminum. However, it is rather difficult to form a bowl shape from the clad sheet, primarily due to the problem of a material spring back. The fabrication of a new type of a pot was made possible by means of the adoption of a forging cast process instead of the clad sheet. In this process, iron powder is inserted between stainless steel and aluminum in order to alleviate the large difference on the coefficient of expansion between each material. It was made clear that the application of two kinds of iron particle, namely 10 μm size powder on the stainless steel side and 44 μm on the aluminum side, enables the joints to become strong enough. The joint strength of the new pot by this fabrication process was confirmed by the tests of the shear strength and the fatigue tests together with the stress analysis.

  13. Weld-brazing of titanium

    NASA Technical Reports Server (NTRS)

    Bales, T. T.; Royster, D. M.; Arnold, W. E., Jr.

    1974-01-01

    A joining process, designated weld-brazing, which combines resistance spotwelding and brazing has been developed at the NASA Langley Research Center. Resistance spot-welding is employed to position and align the parts and to establish a suitable faying surface gap for brazing; it contributes to the integrity of the joint. Brazing enhances the properties of the joint and reduces the stress concentrations normally associated with spotwelds. Ti-6Al-4V titanium alloy joints have been fabricated using 3003 aluminum braze both in a vacuum furnace and in a retort containing an inert gas environment.

  14. [After titanium, peek ?].

    PubMed

    Meningaud, J-P; Spahn, F; Donsimoni, J-M

    2012-11-01

    The PEEK-Optima(®), composite mixture of polyetheretherketon and inert materials, is used in orthopedics, spinal surgery and cranio-facial surgery. It could be used in dental implantology because of its biological and mechanical properties. The results of an experimental and finite element study made on basal implant prototypes, on basal implantology show that PEEK, contrary to titanium, has a compound structure that allows to optimize the distribution of masticatory forces around the implant. These results should be confirmed by a clinical study according to research regulation.

  15. Characterisation of titanium-titanium boride composites processed by powder metallurgy techniques

    SciTech Connect

    Selva Kumar, M.; Chandrasekar, P.; Chandramohan, P.; Mohanraj, M.

    2012-11-15

    In this work, a detailed characterisation of titanium-titanium boride composites processed by three powder metallurgy techniques, namely, hot isostatic pressing, spark plasma sintering and vacuum sintering, was conducted. Two composites with different volume percents of titanium boride reinforcement were used for the investigation. One was titanium with 20% titanium boride, and the other was titanium with 40% titanium boride (by volume). Characterisation was performed using X-ray diffraction, electron probe micro analysis - energy dispersive spectroscopy and wavelength dispersive spectroscopy, image analysis and scanning electron microscopy. The characterisation results confirm the completion of the titanium boride reaction. The results reveal the presence of titanium boride reinforcement in different morphologies such as needle-shaped whiskers, short agglomerated whiskers and fine plates. The paper also discusses how mechanical properties such as microhardness, elastic modulus and Poisson's ratio are influenced by the processing techniques as well as the volume fraction of the titanium boride reinforcement. - Highlights: Black-Right-Pointing-Pointer Ti-TiB composites were processed by HIP, SPS and vacuum sintering. Black-Right-Pointing-Pointer The completion of Ti-TiB{sub 2} reaction was confirmed by XRD, SEM and EPMA studies. Black-Right-Pointing-Pointer Hardness and elastic properties of Ti-TiB composites were discussed. Black-Right-Pointing-Pointer Processing techniques were compared with respect to their microstructure.

  16. Forging Links.

    ERIC Educational Resources Information Center

    Stewig, John Warren

    Blacksmiths and their craft have changed with the times, and as times change for teachers, they too should be forgers of links. Teacher-to-teacher links should extend beyond the faculty lounge to support systems and active groups of individuals concerned about each other. Another personal link can be made by developing a grade level, system-wide…

  17. Titanium in Engine Valve Systems

    NASA Astrophysics Data System (ADS)

    Allison, J. E.; Sherman, A. M.; Bapna, M. R.

    1987-03-01

    Titanium alloys offer a unique combination of high strength-to-weight ratio, good corrosion resistance and favorable high temperature mechanical properties. Still, their relatively high cost has discouraged consideration for widespread use in automotive components. Recent demands for increased fuel economy have led to the consideration of these alloys for use as valve train materials where higher costs might be offset by improvements in performance and fuel economy. Lighter weight valve train components permit the use of lower spring loads, thus reducing friction and increasing fuel economy. Camshaft friction measurements made on a typical small displacement engine indicate that a twoto-four percent increase in fuel economy can be achieved. Valve train components are, however, subject to a severe operating environment, including elevated temperatures, sliding wear and high mechanical loads. This paper discusses the details of alloy and heat treatment selection for optimizing valve performance. When properly manufactured, titanium valves have been shown to withstand very stringent durability testing, indicating the technical feasibility of this approach to fuel economy improvement.

  18. 76 FR 24856 - Heavy Forged Hand Tools (i.e., Axes & Adzes, Bars & Wedges, Hammers & Sledges, and Picks...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-03

    ... From the Federal Register Online via the Government Publishing Office ] DEPARTMENT OF COMMERCE International Trade Administration Heavy Forged Hand Tools (i.e., Axes & Adzes, Bars & Wedges, Hammers & Sledges..., Department of Commerce. SUMMARY: On January 3, 2011, the Department of Commerce (``Department'') initiated...

  19. Fatigue behavior of rolled and forged tungsten at 25°, 280° and 480 °C

    NASA Astrophysics Data System (ADS)

    Habainy, J.; Iyengar, S.; Lee, Y.; Dai, Y.

    2015-10-01

    Pure tungsten has been chosen as the target material at the European Spallation Source facility in Lund. Calculations show that the target temperature can reach 500 °C momentarily during the spallation process, leading to thermal fatigue. Target life estimations require fatigue data at different temperatures and this work focuses on generating such data for pure, unirradiated, rolled and forged tungsten in the range 25°-480 °C. For specimens oriented in the rolling direction, tensile tests at room temperature indicated Young's modulus values in the range 320-390 GPa, low levels of plasticity (<0.23%) and UTS values in the range 397 MPa (unpolished) and 705 MPa (Polished). UTS for forged specimens were around 500 MPa. Stress-controlled fatigue tests were conducted in the tensile regime, with a runout limit of 2 × 106 cycles. At 25 °C, unpolished specimens had fatigue limits of 150 MPa (rolling and transverse direction), and 175 MPa (forged). For polished specimens in the rolling direction, fatigue limits were higher at 237.5 MPa (25 °C) and 252.5 MPa (280 °C). The forged specimens showed slightly better fatigue properties and marginal cyclic hardening at 480 °C.

  20. Forging Research-Teaching Linkages through Action Research: An Example of Facilitating the Development of Competency in Critical Reflection

    ERIC Educational Resources Information Center

    Lowry-O'Neill, Catherine

    2009-01-01

    Action research is an approach to enquiry that forges linkages between research and teaching, with each potentially informing the other in a responsive and creative cycle. This paper provides an overview of a pedagogic action research project which was undertaken in order to respond directly to learning needs expressed by a group of second year…

  1. Ultrasonic Defect Characterization in Heavy Rotor Forgings by Means of the Synthetic Aperture Focusing Technique and Optimization Methods.

    PubMed

    Fendt, Karl T; Mooshofer, Hubert; Rupitsch, Stefan J; Ermert, Helmut

    2016-06-01

    Ultrasonic nondestructive testing of steel forgings aims at the detection and classification of material inhomogeneities to ensure the components fitness for use. Due to the high price and safety critical nature of large forgings for turbomachinery, there is great interest in the application of imaging algorithms to inspection data. However, small flaw indications that cannot be sufficiently resolved have to be characterized using amplitude-based quantification. One such method is the distance gain size method, which converts the maximum echo amplitudes into the diameters of penny-shaped equivalent size reflectors. The approach presented in this contribution combines the synthetic aperture focusing technique (SAFT) with an iterative inversion scheme to locate and quantify small flaws in a more reliable way. Ultrasonic inspection data obtained in a pulse-echo configuration are reconstructed by means of an Synthetic Focusing Technique (SAFT). From the reconstructed data, the amount and approximate location of small flaws are extracted. These predetermined positions, along with the constrained defect model of a penny-shaped crack, provide the initial parametrization for an elastodynamic simulation based on the Kirchhoff approximation. The identification of the optimal parameter set is achieved through an iteratively regularized Gauss-Newton method. By testing the characterization method on a series of flat-bottom holes under laboratory conditions, we demonstrate that the procedure is applicable over a wide range of defect sizes. To show suitability for large forging inspection, we additionally evaluate the inspection data of a large generator shaft forging of 0.6-m diameter.

  2. Jernberg Industries, Inc.: Forging Facility Uses Plant-Wide Energy Assessment to Aid Conversion to Lean Manufacturing (Revised)

    SciTech Connect

    Not Available

    2004-10-01

    Jernberg Industries conducted a plant-wide assessment while converting to lean manufacturing at a forging plant. Seven projects were identified that could yield annual savings of $791,000, 64,000 MMBtu in fuel and 6 million kWh

  3. Quenching and Cold-Work Residual Stresses in Aluminum Hand Forgings : Contour Method Measurement and FEM Prediction

    SciTech Connect

    Prime, M. B.; Newborn, M. A.; Balog, J. A.

    2003-01-01

    The cold-compression stress relief process used to reduce the quench-induced stresses in high-strength aerospace aluminum alloy forgings does not fully relieve the stresses. This study measured and predicted the residual stress in 7050-T74 (solution heat treated, quenched, and artificially overaged) and 7050-T7452 (cold compressed prior to aging) hand forgings. The manufacturing process was simulated by finite element analysis. First, a thermal analysis simulated the quench using appropriate thermal boundary conditions and temperature dependent material properties. Second, a structural analysis used the thermal history and a temperature and strain-rate dependent constitutive model to predict the stresses after quenching. Third, the structural analysis was continued to simulate the multiple cold compressions of the stress relief process. Experimentally, the residual stresses in the forgings were mapped using the contour method, which involved cutting the forgings using wire EDM and then measuring the contour of the cut surface using a CMM. Multiple cuts were used to map different stress components. The results show a spatially periodic variation of stresses that results from the periodic nature of the cold work stress relief process. The results compare favorably with the finite element prediction of the stresses.

  4. 31 CFR 370.40 - Can I be held accountable if my negligence contributes to a forged signature?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Can I be held accountable if my negligence contributes to a forged signature? 370.40 Section 370.40 Money and Finance: Treasury Regulations... Submission of Transaction Requests Through the Bureau of the Public Debt § 370.40 Can I be held...

  5. Microstructure and corrosion behaviour in biological environments of the new forged low-Ni Co-Cr-Mo alloys.

    PubMed

    Hiromoto, Sachiko; Onodera, Emi; Chiba, Akihiko; Asami, Katsuhiko; Hanawa, Takao

    2005-08-01

    Corrosion behaviour and microstructure of developed low-Ni Co-29Cr-(6, 8)Mo (mass%) alloys and a conventional Co-29Cr-6Mo-1Ni alloy (ASTM F75-92) were investigated in saline solution (saline), Hanks' solution (Hanks), and cell culture medium (E-MEM + FBS). The forging ratios of the Co-29Cr-6Mo alloy were 50% and 88% and that of the Co-29Cr-8Mo alloy was 88%. Ni content in the air-formed surface oxide film of the low-Ni alloys was under the detection limit of XPS. The passive current densities of the low-Ni alloys were of the same order of magnitude as that of the ASTM alloy in all the solutions. The passive current densities of all the alloys did not significantly change with the inorganic ions and the biomolecules. The anodic current densities in the secondary passive region of the low-Ni alloys were lower than that of the ASTM alloy in the E-MEM + FBS. Consequently, the low-Ni alloys are expected to show as high corrosion resistance as the ASTM alloy. On the other hand, the passive current density of the Co-29Cr-6Mo alloy with a forging ratio of 50% was slightly lower than that with a forging ratio of 88% in the saline. The refining of grains by further forging causes the increase in the passive current density of the low-Ni alloy.

  6. 78 FR 8587 - Heraeus Kulzer, LLC., Including On-Site Leased Workers from People Link Staffing, Forge Staffing...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-06

    ... Link Staffing, Forge Staffing, Career Transitions and Talent Source; South Bend, Indiana; Amended... information from the company shows that workers leased from Career Transitions and Talent Source were employed... findings, the Department is amending this certification to include workers leased from Career...

  7. Taking the Lead in Science Education: Forging Next-Generation Science Standards. International Science Benchmarking Report. Appendix

    ERIC Educational Resources Information Center

    Achieve, Inc., 2010

    2010-01-01

    This appendix accompanies the report "Taking the Lead in Science Education: Forging Next-Generation Science Standards. International Science Benchmarking Report," a study conducted by Achieve to compare the science standards of 10 countries. This appendix includes the following: (1) PISA and TIMSS Assessment Rankings; (2) Courses and…

  8. Mechanical Behavior of Cryomilled CP-Ti Consolidated via Quasi-Isostatic Forging

    NASA Astrophysics Data System (ADS)

    Ertorer, Osman; Zúñiga, Alejandro; Topping, Troy; Moss, Wes; Lavernia, Enrique J.

    2009-01-01

    Commercially pure (CP) Ti (Grade 2 with chemical composition 0.190 wt pct O, 0.0165 wt pct N, 0.0030 wt pct C, and 0.013 wt pct Fe) was cryomilled in liquid argon and liquid nitrogen for 8 hours. The influence of the milling environment on the chemistry, grain size, and grain-boundary structure of CP-Ti was studied by means of transmission electron microscopy (TEM), X-ray diffraction (XRD), and chemical analysis. The results show that the final average grain size obtained after 8 hours of cryomilling was ˜20 nm, for both liquid nitrogen and liquid argon cryomilling environments. Grains were observed to be heavily deformed and they did not reveal well-defined boundaries between them. Liquid nitrogen and liquid argon cryomilling environments led to differences in the final powder chemistry. Cryomilling in liquid nitrogen resulted in Ti powders with ˜2 wt pct nitrogen, which caused embrittlement that in turn affected the mechanical behavior of the consolidated materials. Cryomilling in liquid argon resulted in powders with slightly higher oxygen levels than those from liquid nitrogen experiments; this was attributed to the use of stearic acid (CH3(CH2)16COOH) as a process control agent (PCA). The cryomilled powders, in the form of various compositional blends from the argon and nitrogen milling experiments, were subsequently consolidated via quasi-isostatic (QI) forging, for mechanical behavior studies. The mechanical testing results showed that the QI-forged 85 pct as-received +15 pct liquid-argon-cryomilled powder blend exhibited ˜30 pct elongation to fracture, with a yield strength (YS) of 601 MPa and an ultimate tensile strength (UTS) of 711 MPa. In the case of 100 pct liquid-argon-cryomilled and QI-forged material, the YS, UTS, and elongation values were 947 and 995 MPa and 4.32 pct, respectively. The mechanical behavior was discussed in terms of the operative microstructure mechanisms. The enhanced ductility noted in the blended powders was discussed in terms

  9. Titanium Mesh Nasal Repair without Nasal Lining.

    PubMed

    Zenga, Joseph; Kao, Katherine; Chen, Collin; Gross, Jennifer; Hahn, Samuel; Chi, John J; Branham, Gregory H

    2017-02-01

    The objective of this study was to describe outcomes for patients who underwent titanium mesh reconstruction of full-thickness nasal defects without internal lining repair. This is a retrospective cohort study. Patients with through-and-through nasal defects were identified at a single academic institution between 2008 and 2016. Nasal reconstruction was performed with either titanium mesh and external skin reconstruction without repair of the intranasal lining or traditional three-layer closure. Five patients underwent titanium mesh reconstruction and 11 underwent traditional three-layer repair. Median follow-up was 11 months (range, 2-66 months). The only significant difference between groups was older age in patients undergoing titanium reconstruction (mean, 81 vs. 63 years; difference of 18; 95% confidence interval [CI], 4-32 years). Defect extent including overall size and structures removed was similar between groups (p > 0.05). Paramedian forehead flap was the most common external reconstruction in both groups (100% for titanium mesh and 73% for three-layer closure). Time under anesthesia was significantly shorter for titanium mesh reconstruction (median, 119 vs. 314 minutes; difference of 195; 95% CI, 45-237). Estimated blood loss and length of hospital stay were similar between groups (p > 0.05). Complication rates were substantial although not significantly different, 40 and 36% in titanium and three-layer reconstruction, respectively (p > 0.05). All patients with complications after titanium reconstruction had prior or postoperative radiotherapy. Titanium mesh reconstruction of through-and-through nasal defects can successfully be performed without reconstruction of the intranasal lining, significantly decreasing operative times. This reconstructive technique may not be suitable for patients who undergo radiotherapy.

  10. Titanium Coating of the Boston Keratoprosthesis

    PubMed Central

    Salvador-Culla, Borja; Jeong, Kyung Jae; Kolovou, Paraskevi Evi; Chiang, Homer H.; Chodosh, James; Dohlman, Claes H.; Kohane, Daniel S.

    2016-01-01

    Purpose We tested the feasibility of using titanium to enhance adhesion of the Boston Keratoprosthesis (B-KPro), ultimately to decrease the risk of implant-associated complications. Methods Cylindrical rods were made of poly(methyl methacrylate) (PMMA), PMMA coated with titanium dioxide (TiO2) over a layer of polydopamine (PMMATiO2), smooth (Ti) and sandblasted (TiSB) titanium, and titanium treated with oxygen plasma (Tiox and TiSBox). Topography and surface chemistry were analyzed by scanning electron microscopy (SEM), atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). Adhesion force between rods and porcine corneas was measured ex vivo. Titanium sleeves, smooth and sandblasted, were inserted around the stem of the B-KPro and implanted in rabbits. Tissue adhesion to the stem was assessed and compared to an unmodified B-Kpro after 1 month. Results X-ray photoelectron spectroscopy demonstrated successful deposition of TiO2 on polydopamine-coated PMMA. Oxygen plasma treatment did not change the XPS spectra of titanium rods (Ti and TiSB), although it increased their hydrophilicity. The materials did not show cell toxicity. After 14 days of incubation, PMMATiO2, smooth titanium treated with oxygen plasma (Tiox), and sandblasted titanium rods (TiSB, TiSBox) showed significantly higher adhesion forces than PMMA ex vivo. In vivo, the use of a TiSB sleeve around the stem of the B-KPro induced a significant increase in tissue adhesion compared to a Ti sleeve or bare PMMA. Conclusions Sandblasted titanium sleeves greatly enhanced adherence of the B-KPro to the rabbit cornea. This approach may improve adhesion with the donor cornea in humans as well. Translational Relevance This approach may improve adhesion with donor corneas in humans. PMID:27152247

  11. Titanium Layer Influence on the Strength of a Hybrid Titanium Composite Laminate

    NASA Technical Reports Server (NTRS)

    Veazie, David R.; Grover, Ronald O., Jr.; Bryant, Genine I.

    1997-01-01

    An experimental study was undertaken to investigate the mechanical response of four hybrid titanium composite laminate (HTCL) systems, each prepared using a graphite fiber reinforced thermoplastic polyimide as the adhesive in a unidirectional prepreg. Two of the four HTCL systems were fabricated with the titanium Ti-15-3 alloy, while the other two systems were fabricated with the titanium Timetal Beta-21S alloy. Each HTCL system consisted of either three plies or four plies of the titanium alloy. Systems with only three plies of titanium had plies measuring 10 mils thick, whereas systems consisting of four plies of titanium had plies measuring 5 mils thick. The improvement in mechanical properties achieved by comparing the uniaxial tensile results of static strength at room temperature. Results included stress-strain curves, ultimate strength, strain-to-failure, initial modulus of the HTCL's, and the description of the observed modes of failure.

  12. Titanium-potassium heat pipe corrosion studies

    SciTech Connect

    Lundberg, L.B.

    1984-07-01

    An experimental study of the susceptibility of wickless titanium/potassium heat pipes to corrosive attack has been conducted in vacuo at 800/sup 0/K for 6511h and at 900/sup 0/K for 4797h without failure or degradation. Some movement of carbon, nitrogen and oxygen was observed in the titanium container tube, but no evidence of attack could be detected in metallographic cross sections of samples taken along the length of the heat pipes. The lack of observable attack of titanium by potassium under these conditions refutes previous reports of Ti-K incompatibility.

  13. Oxygen-Barrier Coating for Titanium

    NASA Technical Reports Server (NTRS)

    Clark, Ronald K.; Unnam, Jalaiah

    1987-01-01

    Oxygen-barrier coating for titanium developed to provide effective and low-cost means for protecting titanium alloys from oxygen in environment when alloys used in high-temperature mechanical or structural applications. Provides protective surface layer, which reduces extent of surface oxidation of alloy and forms barrier to diffusion of oxygen, limiting contamination of substrate alloy by oxygen. Consists of submicron layer of aluminum deposited on surface of titanium by electron-beam evaporation, with submicron layer of dioxide sputtered onto aluminum to form coat.

  14. Isothermal deformation of gamma titanium aluminide

    SciTech Connect

    Srinivasan, R.; Singh, J.P.; Tuval, E.; Weiss, I.

    1996-04-15

    Gamma titanium aluminide has received considerable attention in recent years from the automotive industry as a potential material for making rotating and reciprocating components to produce a quieter and more efficient engine. The objectives of this study were to identify processing routes for the manufacture of automobile valves from gamma titanium aluminide. The issues considered were microstructure and composition of the material, and processing parameters such as deformation rates, temperatures, and total deformation. This paper examines isothermal deformation of gamma titanium aluminide in order to develop a processing window for this type of material.

  15. Stress corrosion cracking of titanium alloys

    NASA Technical Reports Server (NTRS)

    Statler, G. R.; Spretnak, J. W.; Beck, F. H.; Fontana, M. G.

    1974-01-01

    The effect of hydrogen on the properties of metals, including titanium and its alloys, was investigated. The basic theories of stress corrosion of titanium alloys are reviewed along with the literature concerned with the effect of absorbed hydrogen on the mechanical properties of metals. Finally, the basic modes of metal fracture and their importance to this study is considered. The experimental work was designed to determine the effects of hydrogen concentration on the critical strain at which plastic instability along pure shear directions occurs. The materials used were titanium alloys Ti-8Al-lMo-lV and Ti-5Al-2.5Sn.

  16. Gentamicin-Eluting Titanium Dioxide Nanotubes Grown on the Ultrafine-Grained Titanium.

    PubMed

    Nemati, Sima Hashemi; Hadjizadeh, Afra

    2017-01-06

    Titanium (Ti)-based materials is the most appropriate choices for the applications as orthopedic and dental implants. In this regard, ultrafine-grained (UFG) titanium with an enhanced mechanical properties and surface energy has attracted more attention. Titanium dioxide (TiO2) nanotubes grown on the titanium could enhance bone bonding, cellular response and are good reservoirs for loading drugs and antibacterial agents. This article investigates gentamicin loading into and release from the TiO2 nanotubes, grown on the UFG compared to coarse-grained (CG) titanium substrate surfaces. Equal Channel Angular Pressing (ECAP) was employed to produce the UFG structure titanium. TiO2 nanotubes were grown by the anodizing technique on both UFG and CG titanium substrate surfaces. Scanning electron microscopy (SEM) imaging confirmed TiO2 nanotube growth on the surface. The UV-vis spectroscopy analysis results show that the amount of gentamicin load-release in the anodized UFG titanium sample is higher than that of CG one which can be explained in terms of thicker TiO2 nanotube arrays layer formed on UFG sample. Moreover, the anodized UFG titanium samples released the drug in a longer time than CG (1 day for the UFG titanium vs. 3 h for the CG one). Regarding wettability analysis, anodized UFG titanium sample showed more enhanced hydrophilicity than CG counterpart. Therefore, the significantly smaller grain size of pure titanium provided by the ECAP technique coupled with appropriate subsequent anodization treatment not only offers a good combination of biocompatibility and adequate mechanical properties but also it provides a delayed release condition for gentamicin.

  17. Synthesis and controllable wettability of micro- and nanostructured titanium phosphate thin films formed on titanium plates.

    PubMed

    Yada, Mitsunori; Inoue, Yuko; Sakamoto, Ayako; Torikai, Toshio; Watari, Takanori

    2014-05-28

    The hydrothermal treatment of a titanium plate in a mixed aqueous solution of hydrogen peroxide and aqueous phosphoric acid under different conditions results in the formation of various titanium phosphate thin films. The films have various crystal structures such as Ti2O3(H2PO4)2·2H2O, α-titanium phosphate (Ti(HPO4)2·H2O), π-titanium phosphate (Ti2O(PO4)2·H2O), or low-crystallinity titanium phosphate and different morphologies that have not been previously reported such as nanobelts, microflowers, nanosheets, nanorods, or nanoplates. The present study also suggests the mechanisms behind the formation of these thin films. The crystal structure and morphology of the titanium phosphate thin films depend strongly on the concentration of the aqueous hydrogen peroxide solution, the amount of phosphoric acid, and the reaction temperature. In particular, hydrogen peroxide plays an important role in the formation of the titanium phosphate thin films. Moreover, controllable wettability of the titanium phosphate thin films, including superhydrophilicity and superhydrophobicity, is reported. Superhydrophobic surfaces with controllable adhesion to water droplets are obtained on π-titanium phosphate nanorod thin films modified with alkylamine molecules. The adhesion force between a water droplet and the thin film depends on the alkyl chain length of the alkylamine and the duration of ultraviolet irradiation utilized for photocatalytic degradation.

  18. Titanium/titanium nitride temporomandibular joint prosthesis: historical background and a six-year clinical review.

    PubMed

    Bütow, K W; Blackbeard, G A; van der Merwe, A E

    2001-08-01

    The titanium/titanium nitride temporomandibular joint (TTN-TMJ) prosthesis, for the combined replacement of both the joint and the glenoid fossa, was developed in 1992 and introduced clinically in 1994. This joint prosthesis is manufactured from pure titanium and the condylar surfaces, as well as the fossa, are coated with titanium nitride for hardening of the contact surfaces. In two different research projects, the joint were first placed in experimental animals, before they were successfully placed in human subjects. Twenty seven joint prostheses used in human subjects have been analysed for this review.

  19. Essaying the mechanical hypothesis: Descartes, La Forge, and Malebranche on the formation of birthmarks.

    PubMed

    Wilkin, Rebecca M

    2008-01-01

    This essay examines the determination by Cartesians to explain the maternal imagination's alleged role in the formation of birthmarks and the changing notion of monstrosity. Cartesians saw the formation of birthmarks as a challenge through which to demonstrate the heuristic capacity of mechanism. Descartes claimed to be able to explain the transmission of a perception from the mother's imagination to the fetus' skin without having recourse to the little pictures postulated by his contemporaries. La Forge offered a detailed account stating that the failure to explain the maternal imagination's impressions would cast doubt on mechanism. Whereas both characterized the birthmark as a deformation or monstrosity in miniature, Malebranche attributed a role to the maternal imagination in fashioning family likenesses. However, he also charged the mother's imagination with the transmission of original sin.

  20. Investigation of influencing factors on friction during ring test in hot forging using FEM simulation

    NASA Astrophysics Data System (ADS)

    Sethy, Ritanjali; Galdos, Lander; Mendiguren, Joseba; Sáenz de Argandoña, Eneko

    2016-10-01

    Few studies have been undertaken to understand the friction in hot forming, especially when addressing the issue of varying input parameters. Better understanding of their role is therefore needed in order to obtain accurate results in numerical simulations. This paper numerically investigates the high temperature ring compression test to evaluate how frictional behaviour is affected by variations of input parameters (i.e. press velocity, Heat Transfer Coefficient (HTC), processing time, mesh size, material and tool temperature). The high temperature ring-compression process was simulated by means of Finite Element Modelling (FEM) using FORGE-3D software with the ring made of AISI 304L having ratio of outer diameter, inner diameter and height of 30:15:10. According to the results, the HTC and the press velocity have most significant effects on frictional behavior and the calibration curves needed to calculate the friction coefficients after experimental testing.

  1. A Simplified Inverse Approach for the Simulation of Axi-Symmetrical Cold Forging Process

    NASA Astrophysics Data System (ADS)

    Halouani, A.; Li, Y. M.; Abbès, B.; Guo, Y. Q.

    2011-01-01

    This paper presents the formulation of an axi-symmetric element based on an efficient method called "Inverse Approach" (I.A.) for the numerical modeling of cold forging process. In contrast to the classical incremental methods, the Inverse Approach exploits the known shape of the final part and executes the calculation from the final part to the initial billet. The assumptions of the proportional loading and the simplified tool actions make the I.A. calculation very fast. The metal's incompressibility is ensured by the penalty method. The comparison with ABAQUS® and FORGE® shows the efficiency and limitations of the I.A. This simplified method will be a good tool for the preliminary preform design.

  2. Development of Replacements for Phoscoating Used in Forging, Extrusion and Metal Forming Processes

    SciTech Connect

    Kerry Barnett

    2003-03-01

    Many forging, extrusion, heading and other metal forming processes use graphite-based lubricants, phosphate coatings, and other potentially hazardous or harmful substances to improve the tribology of the metal forming process. The application of phosphate-based coatings has long been studied to determine if other synthetic ''clean'' lubricants could provide the same degree of protection afforded by phoscoatings and its formulations. So far, none meets the cost and performance objectives provided by phoscoatings as a general aid to the metal forming industry. In as much as phoscoatings and graphite have replaced lead-based lubricants, the metal forming industry has had previous experience with a legislated requirement to change processes. However, without a proactive approach to phoscoating replacement, many metal forming processes could find themselves without a cost effective tribology material necessary for the metal forming process

  3. Effects of Forged Stock and Pure Aluminum Coating on Cryogenic Performance of Heat Treated Aluminum Mirrors

    NASA Technical Reports Server (NTRS)

    Toland, Ronald W.; Ohl, Raymond G.; Barthelmy, Michael P.; Zewari, S. Wahid; Greenhouse, Matthew A.; MacKenty, John W.

    2003-01-01

    We present the results of an on-going test program designed to empirically determine the effects of different stress relief procedures for aluminum mirrors. Earlier test results identified a preferred heat treatment for flat and spherical mirrors diamond turned from blanks cut out of Al 6061-T651 plate stock. Further tests have been performed on mirrors from forged stock and one set from plate stock coated with Alumiplate(trademark) aluminum coating to measure the effect of these variables on cryogenic performance. The mirrors are tested for figure error and radius of curvature at room temperature and at 80 K for three thermal cycles. We correlate the results of our optical testing with heat treatment and metallographic data.

  4. Development of Iron-based Closed-Cell Foams by Powder Forging and Rolling

    NASA Astrophysics Data System (ADS)

    Paswan, Dayanand; Mistry, Dhananjay; Sahoo, K. L.; Srivastava, V. C.

    2013-08-01

    In the present investigation, an attempt has been made to develop in situ sandwich Fe-based foams using powder forging and rolling. Several metal carbonates are first studied by thermo gravimetric analysis to find out their suitability to be used as foaming agent for iron-based foams. Barium carbonate is found to be the most promising foaming agent among other suitable options studied such as SrCO3, CaCO3, MgCO3, etc. The effects of process parameters such as precursor composition, sintering temperature, foaming temperature and time, and content of foaming agent have been studied. The microstructural characteristics of the sintered precursor have been studied by means of optical and scanning electron microscopy. It was found that a good pore structure can be obtained using 2-3% C in Fe and 3% BaCO3 as foaming agent and by foaming at around 1350 °C for 3-6 min.

  5. Titanium aluminide automotive engine valves

    SciTech Connect

    Hartfield-Wuensch, S.E.; Sperling, A.A.; Morrison, R.S.; Dowling, W.E. Jr.; Allison, J.E.

    1995-12-31

    The low density and high elevated temperature strength make titanium aluminide alloys an excellent candidate for automotive exhaust valve applications. Lighter weight valve train components allow either improved performance or reduction of valve spring loads which reduce noise and friction, thereby improving fuel economy. The key to successful application of TiAl alloys for automotive engine valves is not optimization of strength and ductility, but rather the development of a low-cost, high-volume manufacturing method. Different manufacturing approaches will be discussed in this paper, along with their advantages and disadvantages. Currently, casting appears to be the lowest-cost alternative that produces adequate material properties and emphasis is being placed on this manufacturing approach. The results of several successful engine tests will also be discussed, including results on a binary TiAl alloy. However, these engine tests have indicated that TiAl alloy valves will require tip protection and stem coating.

  6. Adherence of sputtered titanium carbides

    NASA Technical Reports Server (NTRS)

    Brainard, W. A.; Wheeler, D. R.

    1979-01-01

    The study searches for interface treatment that would increase the adhesion of TiC coating to nickel- and titanium-base alloys. Rene 41 (19 wt percent Cr, 11 wt percent Mo, 3 wt percent Ti, balance Ni) and Ti-6Al-4V (6 wt percent Al, 4 wt percent V, balance Ti) are considered. Adhesion of the coatings is evaluated in pin-and disk friction tests. The coatings and interface regions are examined by X-ray photoelectron spectroscopy. Results suggest that sputtered refractory compound coatings adhere best when a mixed compound of coating and substrate metals is formed in the interfacial region. The most effective type of refractory compound interface appears to depend on both substrate and coating material. A combination of metallic interlayer deposition and mixed compound interface formation may be more effective for some substrate coating combinations than either alone.

  7. Corrosion of Titanium Matrix Composites

    SciTech Connect

    Covino, B.S., Jr.; Alman, D.E.

    2002-09-22

    The corrosion behavior of unalloyed Ti and titanium matrix composites containing up to 20 vol% of TiC or TiB{sub 2} was determined in deaerated 2 wt% HCl at 50, 70, and 90 degrees C. Corrosion rates were calculated from corrosion currents determined by extrapolation of the tafel slopes. All curves exhibited active-passive behavior but no transpassive region. Corrosion rates for Ti + TiC composites were similar to those for unalloyed Ti except at 90 degrees C where the composites were slightly higher. Corrosion rates for Ti + TiB{sub 2} composites were generally higher than those for unalloyed Ti and increased with higher concentrations of TiB{sub 2}. XRD and SEM-EDS analyses showed that the TiC reinforcement did not react with the Ti matrix during fabrication while the TiB{sub 2} reacted to form a TiB phase.

  8. Occupational noise exposure in small scale hand tools manufacturing (forging) industry (SSI) in Northern India.

    PubMed

    Singh, Lakhwinder Pal; Bhardwaj, Arvind; Deepak, K K; Bedi, Raman

    2009-08-01

    Occupational noise has been recognized as hazardous for the human beings. A high noise level in forging shops is considered to lower the labour productivity and cause illness however occupational noise is being accepted as an integral part of the job. The present study has been carried out in 5 small scale hand tool forging units (SSI) of different sizes in Northern India in Punjab. Noise levels at various sections were measured. OSHA norms for hearing conservation has been incorporated which includes an exchange rate of 5 dB (A), criterion level at 90 dB (A), criterion time of 8 h, threshold level=80 dB (A), upper limit=140 dB (A) and with F/S response rate. Equivalent sound pressure level (L(eq)) has been measured in various sections of these plants. Noise at various sections like hammer section, cutting presses, punching, grinding and barrelling process was found to be >90 dB (A), which is greater than OSHA norms. A cross-sectional study on the basis of questionnaire has been carried out. The results of which revealed that 68% of the workers are not wearing ear protective equipments out of these 50% were not provided with PPE by the company. About 95% of the workers were suffering speech interference though high noise annoyance was reported by only 20%. It has been established that the maximum noise exposure is being taken by the workers as they are working more than 8h a day for six days per week. More than 90% workers are working 12 to 24 h over time per week which lead to very high noise exposure i.e. 50 to 80% per week higher than exposure time/week in USA or European countries(15, 16)).

  9. FEM simulation for cold press forging forming of the round-fin heat sink

    NASA Astrophysics Data System (ADS)

    Wang, Kesheng; Han, Yu; Zhang, Haiyan; Zhang, Lihan

    2013-05-01

    In this paper, the finite element method is used to investigate the forming process of cold press forging for the round-fin heat sink in the automotive lighting. A series of simulations on the round-fin heat sink forming using the program DEFORM were carried out. The blank thickness and friction coefficient on the formation of round-fin were studied, and the tooling structure with counterpressure on the heat sink formation was also investigated. The results show that the blank thickness is very good for the round-fin formation, and the thicker the blank is, the better the round-fin can be formed; and also When both the punch-blank interface and the die-blank interface have the same value of friction factor, the larger value of friction factor is in favor of round-fin forming, the further investigation reveals that the friction at the punch-blank interface has more significant effect on preventing the initiation of flow-through compared with the friction at the die-blank interface, which implies that the punch-blank interface has more significant effect on the material flow in the formation of round-fin. Meanwhile, The tooling structure with counterpressure is helpful to the formation of round-fin heat sink, which not only ensures the height of each round-fin on the heat sink is uniform but also retards the initiation of flow-through on the reverse side of round-fin. In addition, the experiments of press forging process were conducted to validate the finite element analysis, and the simulation results are in good agreement with the experimental data.

  10. Fracture Mechanics Testing of Titanium 6AL-4V in AF-M315E

    NASA Technical Reports Server (NTRS)

    Sampson, J. W.; Martinez, J.; McLean, C.

    2016-01-01

    The Green Propellant Infusion Mission (GPIM) will demonstrate the performance of AF-M315E monopropellant on orbit. Flight certification requires a safe-life analysis of the titanium alloy fuel tank to ensure inherent processing flaws will not cause failure during the design life of the tank. Material property inputs for this analysis require testing to determine the stress intensity factor for environment-assisted cracking (KEAC) of Ti 6Al-4V in combination with the AF-M315E monopropellant. Testing of single-edge notched, or SE(B), specimens representing the bulk tank membrane and weld material were performed in accordance with ASTM E1681. Specimens with fatigue pre-cracks were loaded into test fixtures so that the crack tips were exposed to AF-M315E at 50 C for a duration of 1,000 hours. Specimens that did not fail during exposure were opened to inspect the crack surfaces for evidence of crack growth. The threshold stress intensity value, KEAC, is the highest applied stress intensity that produced neither a failure of the specimen during the exposure nor showed evidence of crack growth. The threshold stress intensity factor for environment-assisted cracking of the Ti 6Al-4V forged tank material was found to be at least 22 ksivin and at least 31 ksivin for the weld material when exposed to AF-M315E monopropellant.

  11. Fracture Growth Testing of Titanium 6AL-4V in AF-M315E

    NASA Technical Reports Server (NTRS)

    Sampson, Jeffrey W.; Martinez, Jonathan; McLean, Christopher

    2015-01-01

    The Green Propellant Infusion Mission (GPIM) will demonstrate the performance of AF-M315E monopropellant in orbit. Flight certification requires a safe-life analysis of the titanium alloy fuel tank to ensure inherent flaws will not cause failure during the design life. Material property inputs for this analysis require testing to determine the stress intensity factor for environmentally-assisted cracking (K (sub EAC)) of Ti 6Al-4V in combination with the AF-M315E monopropellant. Testing of single-edge notched specimens SE(B) representing the bulk tank membrane and weld material were performed in accordance with ASTM E1681. Specimens with fatigue pre-cracks were loaded into test fixtures so that the crack tips were exposed to the monopropellant at 50 degrees Centigrade for a duration of 1,000 hours. Specimens that did not fail during exposure were opened to inspect the crack surfaces for evidence of crack growth. The threshold stress intensity value, KEAC, is the highest applied stress intensity that produced neither a failure of the specimen during the exposure nor showed evidence of crack growth. The threshold stress intensity factor of the Ti 6Al-4V forged tank material when exposed to AF-M315E monopropellant was found to be at least 22.0 kilopounds per square inch. The stress intensity factor of the weld material was at least 31.3 kilopounds per square inch.

  12. Degreasing of titanium to minimize stress corrosion

    NASA Technical Reports Server (NTRS)

    Carpenter, S. R.

    1967-01-01

    Stress corrosion of titanium and its alloys at elevated temperatures is minimized by replacing trichloroethylene with methanol or methyl ethyl ketone as a degreasing agent. Wearing cotton gloves reduces stress corrosion from perspiration before the metal components are processed.

  13. Copper/nickel eutectic brazing of titanium

    NASA Technical Reports Server (NTRS)

    Kutchera, R. E.

    1971-01-01

    Technique joins titanium or one of its alloys to materials, such as iron, nickel or cobalt base material, or to refractory metals. To ensure formation of a satisfactory bond, the temperature, time, environment and pressure must be controlled.

  14. Investigation of Conditions of Titanium Carbonization - IV

    NASA Technical Reports Server (NTRS)

    Meerson, G. A.; Lipkes, Y. M.

    1949-01-01

    In a previous paper, results are presented of accurate investigations of the processes of titanium carbonization and the succeeding titanium carbide decarbonization as related to the phenomenon of the graphitization of soot by heating at a constant temperature in atmospheres of pure hydrogen and carbon monoxide. These tests showed that the processes of titanium carbonization-decarbonization in an atmosphere of pure gases without nitrogen proceed in the same direction as the analogous processes under the conditions of the production furnace. In this case, however, the presence of admixtures of nitrogen changes the quantitative results of the decarbonization process. Thermodynamic computations confirming the results of previous tests conducted at atmospheric pressure and additional tests of titanium carbonization at lowered pressures are presented herein.

  15. Evaluation of Stress Corrosion Cracking Susceptibility Using Fracture Mechanics Techniques, Part 1. [environmental tests of aluminum alloys, stainless steels, and titanium alloys

    NASA Technical Reports Server (NTRS)

    Sprowls, D. O.; Shumaker, M. B.; Walsh, J. D.; Coursen, J. W.

    1973-01-01

    Stress corrosion cracking (SSC) tests were performed on 13 aluminum alloys, 13 precipitation hardening stainless steels, and two titanium 6Al-4V alloy forgings to compare fracture mechanics techniques with the conventional smooth specimen procedures. Commercially fabricated plate and rolled or forged bars 2 to 2.5-in. thick were tested. Exposures were conducted outdoors in a seacoast atmosphere and in an inland industrial atmosphere to relate the accelerated tests with service type environments. With the fracture mechanics technique tests were made chiefly on bolt loaded fatigue precracked compact tension specimens of the type used for plane-strain fracture toughness tests. Additional tests of the aluminum alloy were performed on ring loaded compact tension specimens and on bolt loaded double cantilever beams. For the smooth specimen procedure 0.125-in. dia. tensile specimens were loaded axially in constant deformation type frames. For both aluminum and steel alloys comparative SCC growth rates obtained from tests of precracked specimens provide an additional useful characterization of the SCC behavior of an alloy.

  16. Effect of Prior and Post-Weld Heat Treatment on Electron Beam Weldments of (α + β) Titanium alloy Ti-5Al-3Mo-1.5V

    NASA Astrophysics Data System (ADS)

    Anil Kumar, V.; Gupta, R. K.; Manwatkar, Sushant K.; Ramkumar, P.; Venkitakrishnan, P. V.

    2016-06-01

    Titanium alloy Ti5Al3Mo1.5V is used in the fabrication of critical engine components for space applications. Double vacuum arc re-melted and (α + β) forged blocks were sliced into 10-mm-thick plates and subjected to electron beam welding (EBW) with five different variants of prior and post-weld heat treatment conditions. Effects of various heat treatment conditions on the mechanical properties of the weldments have been studied. The welded coupons were characterized for microstructure, mechanical properties, and fracture analysis. An optimized heat treatment and welding sequence has been suggested. Weld efficiency of 90% could be achieved. Weldment has shown optimum properties in solution treated and aged condition. Heat-affected zone adjacent to weld fusion line is found to have lowest hardness in all conditions.

  17. Initial cytotoxicity of novel titanium alloys.

    PubMed

    Koike, M; Lockwood, P E; Wataha, J C; Okabe, T

    2007-11-01

    We assessed the biological response to several novel titanium alloys that have promising physical properties for biomedical applications. Four commercial titanium alloys [Super-TIX(R) 800, Super-TIX(R) 51AF, TIMETAL(R) 21SRx, and Ti-6Al-4V (ASTM grade 5)] and three experimental titanium alloys [Ti-13Cr-3Cu, Ti-1.5Si and Ti-1.5Si-5Cu] were tested. Specimens (n = 6; 5.0 x 5.0 x 3.0 mm(3)) were cast in a centrifugal casting machine using a MgO-based investment and polished to 600 grit, removing 250 mum from each surface. Commercially pure titanium (CP Ti: ASTM grade 2) and Teflon (polytetrafluoroethylene) were used as positive controls. The specimens were cleaned and disinfected, and then each cleaned specimen was placed in direct contact with Balb/c 3T3 fibroblasts for 72 h. The cytotoxicity [succinic dehydrogenase (SDH) activity] of the extracts was assessed using the MTT method. Cytotoxicity of the metals tested was not statistically different compared to the CP Ti and Teflon controls (p > 0.05). These novel titanium alloys pose cytotoxic risks no greater than many other commonly used alloys, including commercially pure titanium. The promising short-term biocompatibility of these Ti alloys is probably due to their excellent corrosion resistance under static conditions, even in biological environments.

  18. Oxidation resistant coating for titanium alloys and titanium alloy matrix composites

    NASA Technical Reports Server (NTRS)

    Brindley, William J. (Inventor); Smialek, James L. (Inventor); Rouge, Carl J. (Inventor)

    1992-01-01

    An oxidation resistant coating for titanium alloys and titanium alloy matrix composites comprises an MCrAlX material. M is a metal selected from nickel, cobalt, and iron. X is an active element selected from Y, Yb, Zr, and Hf.

  19. Surface fatigue and failure characteristics of hot-forged powder metal AISI 4620, AISI 4640, and machined AISI 4340 steel spur gears

    NASA Technical Reports Server (NTRS)

    Townsend, Dennis P.

    1987-01-01

    Spur gear surface fatigue endurance tests were conducted to investigate hot forged powder metal AISI 4620 and 4640 steel for use as a gear material, to determine endurance characteristics and to compare the results with machined AISI 4340 and 9310 steel gear materials. The as-forged and unground AISI 4620 gear exhibited a 10 percent fatigue life that was approximately one-fourth of that for AISI 9310 and less than one-half that for the AISI 4340 gears. The forged and finish ground AISI 4620 gears exhibited a 10 percent life, approximately 70 percent that of AISI 9310 and slightly better than that of AISI 4340. The AISI 4640 hot forged gears had less fracture toughness and slightly less fatigue life than the AISI 4620 test gears.

  20. Surface fatigue and failure characteristics of hot forged powder metal AISI 4620, AISI 4640, and machined AISI 4340 steel spur gears

    NASA Technical Reports Server (NTRS)

    Townsend, D. P.

    1986-01-01

    Spur gear surface fatigue endurance tests were conducted to investigate hot forged powder metal AISI 4620 and 4640 steel for use as a gear material, to determine endurance characteristics and to compare the results with machined AISI 4340 and 9310 steel gear materials. The as-forged and unground SISI 4620 gear exhibited a 10 percent fatigue life that was approximately one-fourth of that for AISI 9310 and less than one-half that for the AISI 4340 gears. The forged and finish ground AISI 4620 gears exhibited a 10 percent life, approximately 70 percent that of AISI 9310 and slightly better than that of AISI 4340. The AISI 4640 hot forged gears had less fracture toughness and slightly less fatigue life than the AISI 4620 test gears.

  1. Electrolysis of Titanium Oxide to Titanium in Molten Cryolite Salt

    NASA Astrophysics Data System (ADS)

    Yan, Bennett Chek Kin

    Cost-effective production of titanium is becoming a challenge being tackled in the metallurgical and sustainability sector and technological advancements are required to effectively separate the metal from its oxide. The existing methods of Ti production are extremely energy intensive and slow. This proof-of-concept study investigated the feasibility of separating and capturing Ti from TiO2 through electrolysis after it has been dissolved in a cryolite bath at 1050°C. XRD and SEM/EDS results verified that TiO 2 is only partially reduced. However, addition of Al assisted in the precipitation of Ti in the form of TiAl and TiAl3. Parameters such as electrolysis time, concentration of TiO2, and electrolysis potential were explored. The experiments that were run for 4h, with TiO2 <15wt% of the total bath gave promising results as there was intermetallic formation without the excessive evaporation of cryolite.

  2. The Equilibrium Between Titanium Ions and Titanium Metal in NaCl-KCl Equimolar Molten Salt

    NASA Astrophysics Data System (ADS)

    Wang, Qiuyu; Song, Jianxun; Hu, Guojing; Zhu, Xiaobo; Hou, Jungang; Jiao, Shuqiang; Zhu, Hongmin

    2013-08-01

    The equilibrium between metallic titanium and titanium ions, 3Ti2+ ⇌ 2Ti3+ + Ti, in NaCl-KCl equimolar molten salt was reevaluated. At a fixed temperature and an initial concentration of titanium chloride, the equilibrium was achieved by adding an excess amount of sponge titanium in assistant with bubbling of argon into the molten salt. The significance of this work is that the accurate concentrations of titanium ions have been obtained based on a reliable approach for taking samples. Furthermore, the equilibrium constant {{K}}_{{C}} = (x_{{{{Ti}}^{{ 3 { + }}} }}^{{eql}} )3 /(x_{{{{Ti}}^{{ 2 { + }}} }}^{{eql}} )2 was calculated through the best-fitting method under the consideration of the TiOCl dissolution. Indeed, the final results have disclosed that the stable value of KC could be achieved based on all modifications.

  3. Calcium and titanium release in simulated body fluid from plasma electrolytically oxidized titanium.

    PubMed

    Zhang, Y; Matykina, E; Skeldon, P; Thompson, G E

    2010-01-01

    The release of titanium and calcium species to a simulated body fluid (SBF) at 37 degrees C has been investigated for titanium treated by dc plasma electrolytic oxidation (PEO) in three different electrolytes, namely phosphate, silicate and calcium- and phosphorus-containing. The average rate of release of titanium over a 30 day period in immersion tests, determined by solution analysis, was in the range approximately 1.5-2.0 pg cm(-2) s(-1). Calcium was released at an average rate of approximately 11 pg cm(-2) s(-1). The passive current densities, determined from potentiodynamic polarization measurements, suggested titanium losses of a similar order to those determined from immersion tests. However, the possibility of film formation does not allow for discrimination between the metal releases due to electrochemical oxidation of titanium and chemical dissolution of the coating.

  4. Establishment of a Computer-Aided Design (CAD)/Computer-Aided Manufacturing (CAM) Process for the Production of Cold Forged Gears

    DTIC Science & Technology

    1984-01-01

    Continue on reverse side if necessary and Identify by block number) Computer Aided Design/Manufacturing (CAD/CAM), Spur and Helical Gears, Cold Forging...for cold forging spur and helical gears. The geometry of the spur and helical gears has been obtained from the kinematics of the hobbing/shaper machines...or shaping) to cut the electrode for a helical gear die were then computed using the corrections described above. A computer program called GEARDI

  5. Copper-beryllium alloy, bars, rods, shapes, and forgings 98Cu 1.9Be solution heat treated tb00 (a). (SAE standard)

    SciTech Connect

    1996-09-01

    This specification covers one type of copper-beryllium alloy in the form of bars, rods, forgings, and forging stock. These products have been used typically for parts requiring a combination of high strength, good wear resistance, and corrosion resistance and where electrical conductivity or low magnetic susceptibility may be important, but usage is not limited to such applications. Alloy: C17200 UNS Number: C1720.

  6. Development and Evaluation of Titanium Spacesuit Bearings

    NASA Technical Reports Server (NTRS)

    Rhodes, Richard; Battisti, Brian; Ytuarte, Raymond, Jr.; Schultz, Bradley

    2016-01-01

    The Z-2 Prototype Planetary Extravehicular Space Suit Assembly is a continuation of NASA's Z-series of spacesuits, designed with the intent of meeting a wide variety of exploration mission objectives, including human exploration of the Martian surface. Incorporating titanium bearings into the Z-series space suit architecture allows us to reduce mass by an estimated 23 lbs per suit system compared to the previously used stainless steel bearing race designs, without compromising suit functionality. There are two obstacles to overcome when using titanium for a bearing race- 1) titanium is flammable when exposed to the oxygen wetted environment inside the space suit and 2) titanium's poor wear properties are often challenging to overcome in tribology applications. In order to evaluate the ignitability of a titanium space suit bearing, a series of tests were conducted at White Sands Test Facility (WSTF) that introduced the bearings to an extreme test profile, with multiple failures imbedded into the test bearings. The testing showed no signs of ignition in the most extreme test cases; however, substantial wear of the bearing races was observed. In order to design a bearing that can last an entire exploration mission (approx. 3 years), design parameters for maximum contact stress need to be identified. To identify these design parameters, bearing test rigs were developed that allow for the quick evaluation of various bearing ball loads, ball diameters, lubricants, and surface treatments. This test data will allow designers to minimize the titanium bearing mass for a specific material and lubricant combination and design around a cycle life requirement for an exploration mission. This paper reviews the current research and testing that has been performed on titanium bearing races to evaluate the use of such materials in an enriched oxygen environment and to optimize the bearing assembly mass and tribological properties to accommodate for the high bearing cycle life for an

  7. Defining a method of evaluating die life performance by using finite element models (FEM) and a practical open die hot forging method

    NASA Astrophysics Data System (ADS)

    Marashi, J.; Foster, J.; Zante, R.

    2016-10-01

    Die wear, which is defined as a surface damage or removal of material from one or both of two solid surfaces in a sliding, rolling or impact motion relative to one another, is considered the main cause of tool failure. Wear is responsible for 70% of tool failure and a potential source of high costs; as much as 30% per forging unit in the forging industries [1]. This paper presents a unique wear prediction and measurement method for open die forging using a modified Archard equation, 3D FE simulation (to represent the actual forging process precisely) and an industrial scale forging trial. The proposed tool and experimental design is aimed at facilitating a cost effective method of tool wear analysis and to establish a repeatable method of measurement. It creates a platform to test different type of lubricants and coatings on industrial scale environment. The forging trial was carried out using 2100T Schuler Screw press. A full factorial experiment design was used on 3D simulation to identify the process setting for creating a measurable amount of tool wear. Wear prediction of 28.5 µm based on the simulation correlated with both Infinite Focus Optical Microscope and Coordinate Measuring Machine (CMM) measurement results of the practical trial. Thermal camera reading showed temperature raise on the area with maximum wear, which suggests that increase in contact time, causes thermal softening on tool steel. The measurement showed that abrasive wear and adhesive wear are dominant failure modes on the tool under these process conditions.

  8. Influence of Hot forging on Tribological behavior of Al6061-TiB2 In-situ composites

    NASA Astrophysics Data System (ADS)

    Pradeep kumar, G. S.; Keshavamurthy, R.; kuppahalli, Prabhakar; kumari, Prachi

    2016-09-01

    Al6061-TiB2 metal matrix composite was fabricated by stir casting technique via in-situ reaction, using mixture of Al6061 alloy, Potassium tetraflouroborate salt (KBF4) and tetraflourotitanate (K2TiF6). The cast composites were processed to hot forging, SEM studies; X- ray Diffraction studies (XRD), Microhardness and Dry friction and wear tests. Pin on disc type machine was used to perform tribological tests over a load range of 20-100N and sliding velocities of 0.314-1.57m/s. SEM and XRD studies confirms formation of fine in-situ TiB2 particles. Composites exhibit higher Microhardness, improved wear resistance and Lower COF with formation of TiB2 particles when compared with the unreinforced alloy. Compared to cast alloy and its Composites, forged alloy and its composites show superior Tribological behavior under similar test conditions.

  9. Amorphous titanium-oxide supercapacitors

    PubMed Central

    Fukuhara, Mikio; Kuroda, Tomoyuki; Hasegawa, Fumihiko

    2016-01-01

    The electric capacitance of an amorphous TiO2-x surface increases proportionally to the negative sixth power of the convex diameter d. This occurs because of the van der Waals attraction on the amorphous surface of up to 7 mF/cm2, accompanied by extreme enhanced electron trapping resulting from both the quantum-size effect and an offset effect from positive charges at oxygen-vacancy sites. Here we show that a supercapacitor, constructed with a distributed constant-equipment circuit of large resistance and small capacitance on the amorphous TiO2-x surface, illuminated a red LED for 37 ms after it was charged with 1 mA at 10 V. The fabricated device showed no dielectric breakdown up to 1,100 V. Based on this approach, further advances in the development of amorphous titanium-dioxide supercapacitors might be attained by integrating oxide ribbons with a micro-electro mechanical system. PMID:27767103

  10. Amorphous titanium-oxide supercapacitors

    NASA Astrophysics Data System (ADS)

    Fukuhara, Mikio; Kuroda, Tomoyuki; Hasegawa, Fumihiko

    2016-10-01

    The electric capacitance of an amorphous TiO2-x surface increases proportionally to the negative sixth power of the convex diameter d. This occurs because of the van der Waals attraction on the amorphous surface of up to 7 mF/cm2, accompanied by extreme enhanced electron trapping resulting from both the quantum-size effect and an offset effect from positive charges at oxygen-vacancy sites. Here we show that a supercapacitor, constructed with a distributed constant-equipment circuit of large resistance and small capacitance on the amorphous TiO2-x surface, illuminated a red LED for 37 ms after it was charged with 1 mA at 10 V. The fabricated device showed no dielectric breakdown up to 1,100 V. Based on this approach, further advances in the development of amorphous titanium-dioxide supercapacitors might be attained by integrating oxide ribbons with a micro-electro mechanical system.

  11. Simulations and Experiments of Hot Forging Design and Evaluation of the Aircraft Landing Gear Barrel Al Alloy Structure

    NASA Astrophysics Data System (ADS)

    Ram Prabhu, T.

    2016-04-01

    In the present study, the hot forging design of a typical landing gear barrel was evolved using finite element simulations and validated with experiments. A DEFORM3D software was used to evolve the forging steps to obtain the sound quality part free of defects with minimum press force requirements. The hot forging trial of a barrel structure was carried out in a 30 MN hydraulic press based on the simulation outputs. The tensile properties of the part were evaluated by taking samples from all three orientations (longitudinal, long transverse, short transverse). The hardness and microstructure of the part were also investigated. To study the soundness of the product, fluorescent penetrant inspection and ultrasonic testing were performed in order to identify any potential surface or internal defects in the part. From experiments, it was found that the part was formed successfully without any forging defects such as under filling, laps, or folds that validated the effectiveness of the process simulation. The tensile properties of the part were well above the specification limit (>10%) and the properties variation with respect to the orientation was less than 2.5%. The part has qualified the surface defects level of Mil Std 1907 Grade C and the internal defects level of AMS 2630 Class A (2 mm FBh). The microstructure shows mean grain length and width of 167 and 66 µm in the longitudinal direction. However, microstructure results revealed that the coarse grain structure was observed on the flat surface near the lug region due to the dead zone formation. An innovative and simple method of milling the surface layer after each pressing operation was applied to solve the problem of the surface coarse grain structure.

  12. Hydrogeology and ground-water quality of Valley Forge National Historical Park, Montgomery County, Pennsylvania

    USGS Publications Warehouse

    Sloto, Ronald A.; McManus, B. Craig

    1996-01-01

    Valley Forge National Historical Park is just southwest of the Commodore Semiconductor Group (CSG) National Priorities List (Superfund) Site, a source of volatile organic compounds (VOC's) in ground water. The 7.5-square-mile study area includes the part of the park in Lower Providence and West Norriton Townships in Montgomery County, Pa., and surrounding vicinity. The park is underlain by sedimentary rocks of the Upper Triassic age stockton Formation. A potentiometric-surface map constructed from water levels measured in 59 wells shows a cone of depression, approximately 0.5 mile in diameter, centered near the CSG Site. The cone of depression is caused by the pumping of six public supply wells. A ground-water divide between the cone of depression and Valley Forge National Historical Park provides a hydraulic barrier to the flow of ground water and contaminants from the CSG Site to the park. If pumping in the cone of depression was to cease, water levels would recover, and the ground-water divide would shift to the north. A hydraulic gradient between the CSG Site and the Schuylkill River would be established, causing contaminated ground water to flow to the park. Water samples were collected from 12 wells within the park boundary and 9 wells between the park boundary and the ground-water divide to the north of the park. All water samples were analyzed for physical properties (field determinations), nutrients, common ions, metals and other trace constituents, and VOC's. Water samples from the 12 wells inside the park boundary also were analyzed for pesticides. Concentrations of inorganic constituents in the water samples did not exceed U.S. Environmental Protection Agency maximum contaminant levels. Very low concentrations of organic compounds were detected in some of the water samples. VOC's were detected in water from 76 percent of the wells sampled; the maximum concentration detected was 5.8 micrograms per liter of chloroform. The most commonly detected VOC was

  13. A superior process for forming titanium hydrogen isotopic films

    NASA Technical Reports Server (NTRS)

    Steinberg, R.; Alger, D. L.; Cooper, D. W.

    1975-01-01

    Process forms stoichiometric, continuous, strongly bonded titanium hydrogen isotopic films. Films have thermal and electrical conductivities approximately the same as bulk pure titanium, ten times greater than those of usual thin films.

  14. Engineering titanium surfaces for improving osteointegration

    NASA Astrophysics Data System (ADS)

    Lu, Xiong

    Titanium is one of the most important metallic biomedical materials in clinical applications. One of the key issues for successful application of titanium is the interaction at the interface between the titanium and the bone. The present study focuses on improving the surfaces of titanium to achieve better capability to bond with natural bone (i.e. better osteointegration). The objectives of this work include: (1) Developing microfabrication methods to produce micropatterns on titanium surfaces for promoting osteointegration; (2) Studying the calcium phosphate (Ca-P) formation on the chemical treated titanium surface and elucidating the mechanism of precipitation theoretically; and (3) Evaluating osteoconductivity of engineering titanium surfaces in vitro and in vivo. Through mask electrochemical micromachining (TMEMM), jet electrochemical micromachining (Jet-EMM) and the confined etchant layer technique (CELT) were attempted to produce micropatterns on titanium surfaces. TMEMM has a high etching rate and good reproducibility and was used to produce micro-hole arrays on Ti plates for in vivo testing. The driving force and nucleation rate of Ca-P precipitation in simulated body fluid (SBF) were analyzed based on the classical crystallization theory. SBF supersaturation with respect to HA, OCP and DCPD (dicalcium phosphate) was carefully calculated, considering all the association/dissociation reactions of related ion groups in SBF. The analysis indicates that the nucleation rate of OCP is substantially higher than that of HA, while HA is most thermodynamically stable in SBF. DCPD precipitation is thermodynamically impossible in normal SBF, unless calcium and phosphate ion concentrations of SBF increase. Osteoconduction of Ti6Al4V surfaces under various conditions, including micro-patterned, alkali-treated, micro-patterned plus alkali-treated, and surfaces without any treatment, was evaluated. TMEMM was used to fabricate micro-hole arrays on the titanium alloy

  15. An Assessment of the Ductile Fracture Behavior of Hot Isostatically Pressed and Forged 304L Stainless Steel

    NASA Astrophysics Data System (ADS)

    Cooper, A. J.; Smith, R. J.; Sherry, A. H.

    2017-02-01

    Type 300 austenitic stainless steel manufactured by hot isostatic pressing (HIP) has recently been shown to exhibit subtly different fracture behavior from that of equivalent graded forged steel, whereby the oxygen remaining in the component after HIP manifests itself in the austenite matrix as nonmetallic oxide inclusions. These inclusions facilitate fracture by acting as nucleation sites for the initiation, growth, and coalescence of microvoids in the plastically deforming austenite matrix. Here, we perform analyses based on the Rice-Tracey (RT) void growth model, supported by instrumented Charpy and J-integral fracture toughness testing at ambient temperature, to characterize the degree of void growth ahead of both a V-notch and crack in 304L stainless steel. We show that the hot isostatically pressed (HIP'd) 304L steel exhibits a lower critical void growth at the onset of fracture than that observed in forged 304L steel, which ultimately results in HIP'd steel exhibiting lower fracture toughness at initiation and impact toughness. Although the reduction in toughness of HIP'd steel is not detrimental to its use, due to the steel's sufficiently high toughness, the study does indicate that HIP'd and forged 304L steel behave as subtly different materials at a microstructural level with respect to their fracture behavior.

  16. A Method for Measuring the Hardness of the Surface Layer on Hot Forging Dies Using a Nanoindenter

    NASA Astrophysics Data System (ADS)

    Mencin, P.; van Tyne, C. J.; Levy, B. S.

    2009-11-01

    The properties and characteristics of the surface layer of forging dies are critical for understanding and controlling wear. However, the surface layer is very thin, and appropriate property measurements are difficult to obtain. The objective of the present study is to determine if nanoindenter testing provides a reliable method, which could be used to measure the surface hardness in forging die steels. To test the reliability of nanoindenter testing, nanoindenter values for two quenched and tempered steels (FX and H13) are compared to microhardness and macrohardness values. These steels were heat treated for various times to produce specimens with different values of hardness. The heat-treated specimens were tested using three different instruments—a Rockwell hardness tester for macrohardness, a Vickers hardness tester for microhardness, and a nanoindenter tester for fine scale evaluation of hardness. The results of this study indicate that nanoindenter values obtained using a Nanoindenter XP Machine with a Berkovich indenter reliably correlate with Rockwell C macrohardness values, and with Vickers HV microhardness values. Consequently, nanoindenter testing can provide reliable results for analyzing the surface layer of hot forging dies.

  17. The Influence of Temperature on the Frictional Behavior of Duplex-Coated Die Steel Rubbing Against Forging Brass

    NASA Astrophysics Data System (ADS)

    Ebrahimzadeh, I.; Ashrafizadeh, F.

    2015-01-01

    Improvement of die life under hot forging of brass alloys is considered vital from both economical and technical points of view. One of the best methods for improving die life is duplex coatings. In this research, the influence of temperature on the tribological behavior of duplex-coated die steel rubbing against forging brass was investigated. The wear tests were performed on a pin-on-disk machine from room temperature to 700 °C; the pins were made in H13 hot work tool steel treated by plasma nitriding and by PVD coatings of TiN-TiAlN-CrAlN. The disks were machined from a two-phase brass alloy too. The results revealed that the friction coefficient of this tribosystem went through a maximum at 550 °C and decreased largely at 700 °C. Furthermore, the formation of Cr2O3 caused the reduction of friction coefficient at 700 °C. PVD coatings proved their wear resistance up to 550 °C, well above the working temperature of the brass forging dies.

  18. Microstructures and Mechanical Properties of Ultrafine Grained Ti-47Al-2Cr (at %) Alloy Produced Using Powder Compact Forging

    NASA Astrophysics Data System (ADS)

    Nadakuduru, Vijay N.; Zhang, Deliang; Cao, Peng; Gabbittas, Brian

    Development of innovative techniques to produce gamma TiAl based alloys, with good mechanical properties, while still maintaining ultra fine grain size can be rewarding, but also is a great challenge. In the present study study a Ti-47Al-2Cr (at %) alloy has been synthesized by directly forging green powder compacts of a Ti/Al/Cr composite powder produced by high energy mechanical milling of a mixture of elemental Ti, Al, Cr powders. It has been found that the density of the bulk consolidated alloy sample after forging decreases from 95% of the theoretical density in the central region to 84% in the periphery region. The microstructure of the bulk alloy consisted of several Ti rich regions, which was expected to be mainly due to initial powder condition. The room temperature tensile strength of the samples produced from this process was found to be in the range of 115 - 130 MPa. The roles of canning and green powder compact density in determining the forged sample porosity level and distribution are discussed.

  19. Effect of solution treatment on stress corrosion cracking behavior of an as-forged Mg-Zn-Y-Zr alloy

    NASA Astrophysics Data System (ADS)

    Wang, S. D.; Xu, D. K.; Wang, B. J.; Sheng, L. Y.; Han, E. H.; Dong, C.

    2016-07-01

    Effect of solid solution treatment (T4) on stress corrosion cracking (SCC) behavior of an as-forged Mg-6.7%Zn-1.3%Y-0.6%Zr (in wt.%) alloy has been investigated using slow strain rate tensile (SSRT) testing in 3.5 wt.% NaCl solution. The results demonstrated that the SCC susceptibility index (ISCC) of as-forged samples was 0.95 and its elongation-to-failure (εf) was only 1.1%. After T4 treatment, the SCC resistance was remarkably improved. The ISCC and εf values of T4 samples were 0.86 and 3.4%, respectively. Fractography and surface observation indicated that the stress corrosion cracking mode for as-forged samples was dominated by transgranular and partially intergranular morphology, whereas the cracking mode for T4 samples was transgranular. In both cases, the main cracking mechanism was associated with hydrogen embrittlement (HE). Through alleviating the corrosion attack of Mg matrix, the influence of HE on the SCC resistance of T4 samples can be greatly suppressed.

  20. Effect of solution treatment on stress corrosion cracking behavior of an as-forged Mg-Zn-Y-Zr alloy.

    PubMed

    Wang, S D; Xu, D K; Wang, B J; Sheng, L Y; Han, E H; Dong, C

    2016-07-08

    Effect of solid solution treatment (T4) on stress corrosion cracking (SCC) behavior of an as-forged Mg-6.7%Zn-1.3%Y-0.6%Zr (in wt.%) alloy has been investigated using slow strain rate tensile (SSRT) testing in 3.5 wt.% NaCl solution. The results demonstrated that the SCC susceptibility index (ISCC) of as-forged samples was 0.95 and its elongation-to-failure (εf) was only 1.1%. After T4 treatment, the SCC resistance was remarkably improved. The ISCC and εf values of T4 samples were 0.86 and 3.4%, respectively. Fractography and surface observation indicated that the stress corrosion cracking mode for as-forged samples was dominated by transgranular and partially intergranular morphology, whereas the cracking mode for T4 samples was transgranular. In both cases, the main cracking mechanism was associated with hydrogen embrittlement (HE). Through alleviating the corrosion attack of Mg matrix, the influence of HE on the SCC resistance of T4 samples can be greatly suppressed.