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1

Electrical Discharge Machining (EDM).  

National Technical Information Service (NTIS)

The objectives of this program were to increase the efficiency of the electrical discharge machining process, decrease manufacturing costs, increase reliability and structural integrity of production parts, and extend the utilization of EDM manufacturing ...

D. J. Moracz

1973-01-01

2

An on-line monitoring system for a micro electrical discharge machining (micro-EDM) process  

NASA Astrophysics Data System (ADS)

A pulse-type discriminating system to monitor the process of micro electrical discharge machining (micro-EDM) is developed and implemented. The specific features are extracted and the pulses from a RC-type power source are classified into normal, effective arc, transient short circuit and complex types. An approach to discriminate the pulse type according to three durations measured at three pre-determined voltage levels of a pulse is proposed. The developed system is verified by using simulated signals. Discrimination of the pulse trains in actual machining processes shows that the pulses are mainly the normal type for micro wire-EDM and micro-EDM milling. The pulse-type distribution varies during the micro-EDM drilling process. The percentage of complex-type pulse increases monotonically with the drilling depth. It starts to drop when the gap condition is seriously deteriorated. Accordingly, an on-line monitoring strategy for the micro-EDM drilling process is proposed.

Liao, Y. S.; Chang, T. Y.; Chuang, T. J.

2008-03-01

3

Analysis of aerosol emission and hazard evaluation of electrical discharge machining (EDM) process.  

PubMed

The safety and environmental aspects of a manufacturing process are important due to increased environmental regulations and life quality. In this paper, the concentration of aerosols in the breathing zone of the operator of Electrical Discharge Machining (EDM), a commonly used non traditional manufacturing process is presented. The pattern of aerosol emissions from this process with varying process parameters such as peak current, pulse duration, dielectric flushing pressure and the level of dielectric was evaluated. Further, the HAZOP technique was employed to identify the inherent safety aspects and fire risk of the EDM process under different working conditions. The analysis of aerosol exposure showed that the concentration of aerosol was increased with increase in the peak current, pulse duration and dielectric level and was decreased with increase in the flushing pressure. It was also found that at higher values of peak current (7A) and pulse duration (520 micros), the concentration of aerosols at breathing zone of the operator was above the permissible exposure limit value for respirable particulates (5 mg/m(3)). HAZOP study of the EDM process showed that this process is vulnerable to fire and explosion hazards. A detailed discussion on preventing the fire and explosion hazard is presented in this paper. The emission and risk of fire of the EDM process can be minimized by selecting proper process parameters and employing appropriate control strategy. PMID:20720340

Jose, Mathew; Sivapirakasam, S P; Surianarayanan, M

2010-01-01

4

TECHNICAL NOTE: Fabrication of microelectrodes for EDM machining by a combined etching process  

NASA Astrophysics Data System (ADS)

In this note, multi-headed microelectrodes were machined by a combined sequence process of WEDG, ultrasonic-aided chemical etching and an electrochemical anodic etching procedure. Electrodes were cut to 0.1 mm by a wire EDM machine from an original diameter of 3 mm in the first step. Electrodes were continually machined by chemical etching and anodic electrochemical etching. During electrolysis, copper impurity produced on the anode is not easily removed from its matrix. A ultrasonic mechanism was utilized to agitate the ferric chloride solution to clean the surface impurity off the electrode. The performance of ultrasonic-aided chemical etching was also studied. Micro single electrodes and foil electrodes were processed by chemical etching. Multi-headed microelectrodes can be machined to 30 µm by the combined sequence etching technology proposed.

Weng, Feng-Tsai

2004-05-01

5

Increase of process reliability in the micro-machining processes EDM-milling and laser ablation using on-machine sensors  

Microsoft Academic Search

In micro production micro electric discharge machining (?EDM) and laser ablation are two established manufacturing methods. Due to the thermal material removal mechanism there are some challenges to provide the needed process reliability. In both cases it is important to ensure a precise manufacturing process by the correct positioning of the tool, e.g. the laser spot, relative to the work

V. Schulze; P. Weber; C. Ruhs

6

Optimization of Correlated Responses of EDM Process  

Microsoft Academic Search

Electrical discharge machining (EDM) process has several important performance measures (responses), some of which are correlated. For example, material removal rate (MRR) and electrode wear rate (EWR) are highly correlated. No reported research work on EDM process has taken into consideration the possible correlation between the response variables while determining the optimal process conditions. Thus, the results achieved by the

Rina Chakravorty; Susanta Kumar Gauri; Shankar Chakraborty

2011-01-01

7

Optimization of Correlated Responses of EDM Process  

Microsoft Academic Search

Electrical discharge machining (EDM) process has several important performance measures (responses), some of which are correlated. For example, material removal rate (MRR) and electrode wear rate (EWR) are highly correlated. No reported research work on EDM process has taken into consideration the possible correlation between the response variables while determining the optimal process conditions. Thus, the results achieved by the

Rina Chakravorty; Susanta Kumar Gauri; Shankar Chakraborty

2012-01-01

8

Processing of Zirconium-Based Bulk Metallic Glass (BMG) Using Micro Electrical Discharge Machining (Micro-EDM)  

Microsoft Academic Search

A zirconium-based bulk metallic glass was machined by micro electrical discharge machining (micro-EDM) to demonstrate its feasibility under discharge energies typical of the microregime. Furthermore, input energies of 13.4 µJ and 0.9 µJ, and three different tool electrodes, namely, tungsten rod electrode, copper, and brass tube electrodes were employed to elucidate the effects of different machining conditions on the machined surface roughness,

Swee Hock Yeo; Peng Cheong Tan; Erwin Aligiri; Shu Beng Tor; Ngiap Hiang Loh

2009-01-01

9

Vertical EDM (Electric Discharge Machining) Using Modular Programming.  

National Technical Information Service (NTIS)

The usual function of computer numerically controlled (CNC) machining programs is to specify a sequence of machining operations. When CNC is applied to electric discharge machining (EDM), the possibilities and needs are much greater. This paper describes ...

J. E. Fuller

1989-01-01

10

EDM Machine Modified For Micro Drilling In DAC Experiments  

NASA Astrophysics Data System (ADS)

A JOEMARS Electric discharge machine (EDM) has been modified for micro drilling of gasket holes for high pressure experiments using a diamond anvil cell. We were able to use normal tungsten carbide drill bits that are used for drilling micro holes manually with the EDM. The drilled holes were free of burr formation and had a nice surface finish.

Lonappan, Dayana; Shekar, N. V. Chandra; Sundaram, L. M.; Edwin, T.; Sahu, P. Ch.

2011-07-01

11

Evaluating the electrical discharge machining (EDM) parameters with using carbon nanotubes  

NASA Astrophysics Data System (ADS)

Electrical discharge machining (EDM) is one of the most accurate non traditional manufacturing processes available for creating tiny apertures, complex or simple shapes and geometries within parts and assemblies. Performance of the EDM process is usually evaluated in terms of surface roughness, existence of cracks, voids and recast layer on the surface of product, after machining. Unfortunately, the high heat generated on the electrically discharged material during the EDM process decreases the quality of products. Carbon nanotubes display unexpected strength and unique electrical and thermal properties. Multi-wall carbon nanotubes are therefore on purpose added to the dielectric used in the EDM process to improve its performance when machining the AISI H13 tool steel, by means of copper electrodes. Some EDM parameters such as material removal rate, electrode wear rate, surface roughness and recast layer are here first evaluated, then compared to the outcome of EDM performed without using nanotubes mixed to the dielectric. Independent variables investigated are pulse on time, peak current and interval time. Experimental evidences show that EDM process operated by mixing multi-wall carbon nanotubes within the dielectric looks more efficient, particularly if machining parameters are set at low pulse of energy.

Sari, M. M.; Noordin, M. Y.; Brusa, E.

2012-09-01

12

A fatigue study of electrical discharge machine (EDM) strain-gage balance materials  

NASA Technical Reports Server (NTRS)

A fatigue study was undertaken to determine how much electrical-discharge-machine (EDM) processing affected the fatigue life of balance materials: EDM and regular milling-machine (MM) samples were compared. Simulation of a typical balance stress configuration was devised for the fatigue testing in order to obtain results more closely related to balance situations. The fatigue testing of the EDM and MM specimens has indicated that the EDM technique does indeed reduce the fatigue life of 15-5PH steel, the first balance material tested. This conclusion was based on comparisons of the specimen fatigue lives with theoretical and manufacturer's data. Hence the EDM surface effects are detrimental to the fatigue life of this balance material.

Rhew, Ray D.

1989-01-01

13

A study on the quality of micro-hole of Ti-6Al-4V by EDM process with on-machine measurement techniques  

NASA Astrophysics Data System (ADS)

A new on-machine measurement technique is proposed to observe the quality of micro-hole in micro Electrical Discharge Machining (EDM) progress. Images of micro-hole are captured by means of a simple configuration use a light-emitting diode (LED) illuminator, optical fiber, and a camera charge-coupled device (CCD).The device does not make contact with workpiece and acquire the image from the contour of the finished micro-hole. Because of using the optical fiber to transmit the real-time image, the device can woke in the narrow and small place. Based on the detected feature points, the geometrical features of the finished micro-hole such as its aperture can be obtained in real time. Meanwhile, the measuring result shows the micro-hole is whether or not qualified and can optimize the process parameters.

Li, Jun; Liu, Xiaoyu; Wei, Xingping; Zhao, Shiping

2013-10-01

14

Optimization of EDM machining parameters using DMLS electrode  

Microsoft Academic Search

Purpose – The purpose of this paper is to optimise the electro-discharge machining (EDM) parameters and investigate feasibility of using direct metal laser sintering (DMLS) parts as EDM electrodes. Design\\/methodology\\/approach – In this paper the effects of discharge current, pulse-on-time, flushing pressure are optimized for minimum tool wear rate (TWR), maximum metal removal rate (MRR) and minimum surface roughness (Ra).

Vijay Kumar Meena; Nagahanumaiah

2006-01-01

15

Micro-spherical probes machining by EDM  

NASA Astrophysics Data System (ADS)

This paper describes a new hybrid micro-machining method, which combines wire electro discharge grinding technology with one pulse electro discharge, to fabricate micro-spherical probes and micro-spherical cavities. The results show that a burnished micro-spherical probe with about 40 µm diameter could be formed instantaneously with the hybrid machining process, which is not available in the conventional micro-machining method. The deviation in diameter and roundness tolerances of micro-spherical probes is about 1 µm and 3 µm, respectively. Compared with conventional electro discharge machining, the surface roughness of the spherical probe is much smaller than a discharge crater. It will be possible to achieve more accurate three-dimensional measurements with the micro-spherical probe attached to the coordinate measuring machine in the future.

Sheu, Dong-Yea

2005-01-01

16

Study on ultra-fine w-EDM with on-machine measurement-assisted  

SciTech Connect

The purpose of this study was to develop the on-machine measurement techniques so as to precisely fabricate micro intricate part using ultra-fine w-EDM. The measurement-assisted approach which employs an automatic optical inspection (AOI) is incorporated to ultra-fine w-EDM process to on-machine detect the machining error for next re-machining. The AOI acquires the image through a high resolution CCD device from the contour of the workpiece after roughing in order to further process and recognize the image for determining the residual. This facilitates the on-machine error detection and compensation re-machining. The micro workpiece and electrode are not repositioned during machining. A fabrication for a micro probe of 30-{mu}m diameter is rapidly machined and verified successfully. Based on the proposed technique, on-machine measurement with AOI has been realized satisfactorily.

Chen Shuntong [Department of Mechatronic Technology, National Taiwan Normal University (China); Yang Hongye [Department of Industrial Education, National Taiwan Normal University (China)

2011-01-17

17

Study on ultra-fine w-EDM with on-machine measurement-assisted  

NASA Astrophysics Data System (ADS)

The purpose of this study was to develop the on-machine measurement techniques so as to precisely fabricate micro intricate part using ultra-fine w-EDM. The measurement-assisted approach which employs an automatic optical inspection (AOI) is incorporated to ultra-fine w-EDM process to on-machine detect the machining error for next re-machining. The AOI acquires the image through a high resolution CCD device from the contour of the workpiece after roughing in order to further process and recognize the image for determining the residual. This facilitates the on-machine error detection and compensation re-machining. The micro workpiece and electrode are not repositioned during machining. A fabrication for a micro probe of 30-?m diameter is rapidly machined and verified successfully. Based on the proposed technique, on-machine measurement with AOI has been realized satisfactorily.

Chen, Shun-Tong; Yang, Hong-Ye

2011-01-01

18

Development of an Eco-Friendly Electrical Discharge Machine (E-EDM) Using TRIZ Approach  

NASA Astrophysics Data System (ADS)

Electrical Discharge Machine (EDM) is one of the non-traditional machining processes. EDM process is based on thermoelectric energy between the work and an electrode. A pulse discharge occurs in a small gap between the work piece and the electrode and removes the unwanted material from the parent metal through melting and vaporization. The electrode and the work piece must have an electrical conductivity in order to generate the spark. Dielectric fluid acts as a spark conductor, concentrating the energy to a very narrow region. There are various types of products can be produced and finished using EDM such as Moulds, Dies, Parts of Aerodynamics, Automotives and Surgical components. This research work reveals how an Eco friendly EDM (E-EDM) can be modeled to replace die electric fluid and introducing ozonised oxygen in to EDM to eliminate harmful effects generated while machining by using dielectric, to make pollution free machining environment through a new design of EEDM using TRIZ (a Russian acronym for Theory of Inventive Problem Solving) approach, since Eco friendly design is the need of the hour.

Sreebalaji, V. S.; Saravanan, R.

19

Positional accuracy study of a micro-EDM machine  

NASA Astrophysics Data System (ADS)

Micro-electrodischarge machining is used to machine small features such as holes, cavities and slots with high aspect ratios in electrically-conductive materials for various applications including medical implants, printing devices, dies and spray nozzles. In this study, the positional accuracy of a micro-EDM machine was assessed while simulating the machining of an array of holes. The measurement involved the use of a diffraction grid plate and non-contact scanning head. This enabled various conclusions to be drawn as to the relative deviations experienced when machining small features such as (phi) 50 micrometers holes.

Almond, Heather J.; Bhogal, Jagmohan; Allen, David M.

1999-03-01

20

Micro-hole machining using micro-EDM combined with electropolishing  

NASA Astrophysics Data System (ADS)

This paper presents a novel process of using micro-electro-discharge- machining (micro-EDM) combined with electropolishing to improve the surface roughness of micro-holes. During the machining process, a tool is fabricated by wire electro-discharge grinding (WEDG) directly by using micro-EDM for machining the micro-hole and by electropolishing to finish the hole wall. In this work, various micro-holes are machined on the high nickel alloy. By the electropolishing method, high surface quality of the hole wall is obtained by applying a suitable electrolytic voltage and an appropriate concentration of electrolyte in about 5 min of machining time. The taper and burrs of the inlet of holes are reduced, even for difficult- to-machine special-shaped micro-holes. The surface roughness reduced from 2.11 µm Rmax before grinding to 0.69 µm Rmax after electropolishing.

Hung, Jung-Chou; Yan, Biing-Hwa; Liu, Hung-Sung; Chow, Han-Ming

2006-08-01

21

EFFECT OF POWDER MIXED DIELECTRIC ON MACHINING PERFORMANCE IN ELECTRIC DISCHARGE MACHINING (EDM)  

Microsoft Academic Search

In this study, the variations of machining performance outputs, namely, workpiece surface roughness, workpiece removal rate, electrode wear rate, relative wear, workpiece surface hardness, and workpiece surface microstructure were experimentally investigated with the varying machining parameters for metal powder mixed dielectric liquid in electrical discharge machining (EDM). The machining tests were conducted by using prismatic steel workpiece and copper electrodes

Bekir ÖZERKAN; Can ÇO?UN

22

Surface Integrity of C-40 Steel Processed with WC-Cu Powder Metallurgy Green Compact Tools in EDM  

Microsoft Academic Search

Electric discharge machining (EDM) is an electrothermal process where recast layer on the machined surface and heat-affected (HAZ) zone just below the machined surface are common phenomena. Thus, the assessment of surface integrity in EDM is a very important task. In this study, an attempt was made to modify the surface integrity of C-40 steel in EDM. WC-Cu powder metallurgy

P. K. Patowari; U. K. Mishra; P. Saha; P. K. Mishra

2011-01-01

23

Taguchi Method Implementation in Taper Motion Wire EDM Process Optimization  

NASA Astrophysics Data System (ADS)

Wire electrical discharge machining (Wire EDM) is a non-conventional metal removal process as well as one of the best manufacturing processes suitable for producing jigs, fixtures, and dies. Among others, the machine is able to cut a workpiece having oblique and taper form. The objective of this paper is to optimize the input parameters of Wire EDM machine, such as no load voltage, capacitor, on-time, off-time, and servo voltage, for machining medium carbon steel ASSAB 760. The Taguchi design of experiments, the signal-to-noise ratio, and analysis of variance are employed to analyze the effects of the input parameters by adopting L18 Taguchi orthogonal array (OA) to conduct experiments using brass wire electrode of 0.2 mm in diameter. In order to achieve the maximum material removal rate (MRR) or the minimum surface roughness (SR), six controllable factors, i.e., the parameters of each at three levels are applied for determining the optimal combination of factors and levels. The results reveal that the MRR and the SR are greatly influenced by the on-time and the taper angle, respectively. Experimental results affirm the effectiveness of the method, and also prove that the Taguchi method is suitable to solving the stated problem within minimum number of experiments as compared to that of a full factorial design.

Martowibowo, S. Y.; Wahyudi, A.

2012-10-01

24

Using a helical micro-tool in micro-EDM combined with ultrasonic vibration for micro-hole machining  

NASA Astrophysics Data System (ADS)

This paper presents a novel process using micro-electro-discharge- machining (micro-EDM) combined with ultrasonic vibration by a helical micro-tool electrode to drill and finish micro-holes. During the machining processes, a micro-tool is directly fabricated by wire electro-discharge grinding (WEDG) using micro-EDM combined with various methods for machining the micro-hole and by ultrasonic vibration to finish the hole wall. In this work, circular micro-holes are machined in a high nickel alloy by cylindrical and helical electrodes. Using a helical micro-tool electrode for micro-EDM combined with ultrasonic vibration (HE-MEDM-UV) can substantially reduce the EDM gap, taper and machining time for deep micro-hole drilling. In addition, using a helical micro-tool with micro ultrasonic vibration finishing (HE-MUVF), good surface quality and less taper of the hole wall can be obtained by applying a suitable electrode step variation, rotational speed and ultrasonic amplitude with a machining time of approximately 25 min. According to scanning electron microscopy (SEM) micrographs and atomic force microscopy (AFM) measurement, HE-MUVF can indeed improve the surface roughness from 1.345 µm Rmax before finishing to 0.58 µm Rmax after HE-MUVF. This result demonstrates that using HE-MEDM-UV combined with MUVF can yield micro-holes of precise shape and smooth surface.

Hung, Jung-Chou; Lin, Jui-Kuan; Yan, Biing-Hwa; Liu, Hung-Sung; Ho, Ping-Hsing

2006-12-01

25

Fabrication Of Micro-Nozzles Via ?-EDM Process  

NASA Astrophysics Data System (ADS)

Since traditional handling mechanisms have an unpredictable behavior at micro scale, micro-assembly is a bottleneck in the development of hybrid micro-systems, and the development of new approaches is strongly demanded. In this paper, a recent study of the fabrication of a ceramics vacuum micro-gripper to handle parts in the range of hundreds of microns (300-1000) is presented. Among the possible micro manufacturing processes, micro-EDM has been selected as proving to be a very competitive fabrication technology for the manufacturing of ultra miniature components and micro sized features. The influence of the process parameters on the machining performance of interest is firstly investigated; then, the experimental results on machining the micro gripper are presented, finally concluding remarks are given.

Modica, F.; Ferraris, E.; Trotta, G.; Fassi, I.; Reynaerts, D.

2011-01-01

26

Modeling and analysis of the rapidly resolidified layer of SG cast iron in the EDM process through the response surface methodology  

Microsoft Academic Search

The rapidly resolidified layer is formed by the re-solidification of residual molten material on the machined surface during the electric discharge machining (EDM) process. This paper presents a systematic methodology for modeling and analysis of the rapidly resolidified layer of spheroidal graphite (SG) cast iron in the EDM process using the response surface methodology (RSM). The factors of second phase

Ko-Ta Chiang; Fu-Ping Chang; De-Chang Tsai

2007-01-01

27

Performance analysis of EDM electrode fabricated by localized electrochemical deposition for micro-machining of stainless steel  

Microsoft Academic Search

Electrical discharge machining (EDM) is an important and widely used process for the fabrication of complex three-dimensional\\u000a structure of micro-tools, micro-components, and parts with micro-feature. It allows high precision, low setup cost, large\\u000a freedom of design, and good surface quality. However, in order to produce different varieties of high-accuracy structures\\u000a on machine, microelectrode fabrication is necessary so as to reduce

Mohammad Ahsan Habib; Mustafizur Rahman

2010-01-01

28

New developments in the process control of the hybrid electro chemical discharge machining (ECDM) process  

Microsoft Academic Search

Electro chemical discharge machining (ECDM) is a hybrid non-conventional manufacturing process which combines the features of electro chemical machining (ECM) and electro discharge machining (EDM). One of the major advantages of ECDM, over ECM or EDM, is that the combined metal removal mechanisms in ECDM, yields a much higher machining rate. This paper presents new developments in process control for

T. K. K. R. Mediliyegedara; A. K. M. De Silva; D. K. Harrison; J. A. McGeough

2005-01-01

29

EDM machinability of SiCw/Al composites  

NASA Technical Reports Server (NTRS)

Machinability of high temperature composites was investigated. Target materials, 15 and 25 vol pct SiC whisker-2124 aluminum composites, were machined by electrodischarge sinker machining and diamond saw. The machined surfaces of these metal matrix composites were examined by SEM and profilometry to determine the surface finish. Microhardness measurements were also performed on the as-machined composites.

Ramulu, M.; Taya, M.

1989-01-01

30

Electrical discharge machining (EDM) of Inconel 718 by using copper electrode at higher peak current and pulse duration  

NASA Astrophysics Data System (ADS)

This experimental work is an attempt to investigate the performance of Copper electrode when EDM of Nickel Based Super Alloy, Inconel 718 is at higher peak current and pulse duration. Peak current, Ip and pulse duration (pulse on-time), ton are selected as the most important electrical pulse parameters. In addition, their influence on material removal rate (MRR), electrode wear rate (EWR), and surface roughness (Ra) are experimentally investigated. The ranges of 10 mm diameter of Copper electrode are used to EDM of Inconel 718. After the experiments, MRR, EWR, and Ra of the machined surfaces need to be measured in order to evaluate the performance of the EDM process. In order to obtain high MRR, higher peak current in range of 20A to 40A and pulse duration in range of 200?s to 400?s were used. Experimental results have shown that machining at a highest peak current used of 40A and the lowest pulse duration of 200?s used for the experiment yields the highest material removal rate (MRR) with value 34.94 mm3/min, whereas machining at a peak current of 20A and pulse duration of 400?s yields the lowest electrode wear rate (EWR) with value -0.0101 mm3/min. The lowest surface roughness (Ra) is 8.53 ?m achieved at a lowest peak current used of 20A and pulse duration of 200?s.

Ahmad, S.; Lajis, M. A.

2013-12-01

31

A comparative analysis of machining characteristics in ultrasonic assisted EDM by the response surface methodology  

Microsoft Academic Search

This paper comprehensively evaluates the influence of ultrasonic irradiation of spark gap on EDM characteristics for both planing and drilling operations. A set of comparative experiments were carried out and the analysis of the results was based on standard statistical techniques. The response surfaces and the corresponding response functions were determined for major performance indices, such as machining rate, tool

V. S. R. MURTI; P. K. PHILIP

1987-01-01

32

Traveling wire electrode increases productivity of Electrical Discharge Machining /EDM/ equipment  

NASA Technical Reports Server (NTRS)

Traveling wire electrode on electrical discharge machining /EDM/ equipment reduces the time requirements for precision cutting. This device enables cutting with a minimum of lost material and without inducing stress beyond that inherent in the material. The use of wire increases accuracy and enables tighter tolerances to be maintained.

Kotora, J., Jr.; Smith, S. V.

1967-01-01

33

Finishing effect of abrasive flow machining on micro slit fabricated by wire-EDM  

Microsoft Academic Search

This experimental research use the method of abrasive flow machining (AFM) to evaluate the characteristics of various levels\\u000a of roughness and finishing of the complex shaped micro slits fabricated by wire electrical discharge machining (Wire-EDM).\\u000a An investigative methodology based on the Taguchi experimental method for the micro slits of biomedicine was developed to\\u000a determine the parameters of AFM, including abrasive

Hsinn-Jyh Tzeng; Biing-Hwa Yan; Rong-Tzong Hsu; Han-Ming Chow

2007-01-01

34

Residual stresses and white layer in electric discharge machining (EDM)  

NASA Astrophysics Data System (ADS)

The effect of dielectric liquid and electrode type on white layer structure in electric discharge machined surfaces has been studied in terms of retained austenite and residual stresses using X-ray diffraction method. The machining tests were conducted by using two different tool electrodes (copper and graphite) and dielectric liquid (kerosene and de-ionized water) under same operational conditions. The present work suggests that the surface is saturated with carbon irrespective of the tool electrode material when machining with kerosene dielectric liquid. But, retained austenite is formed on the surface due to carbon uptake from graphite tool electrode when machining with de-ionized water dielectric liquid. On the other hand, even though surface residual stresses increase with structural non-homogeneities in the white layer, no clear consequences have been observed in residual stress distribution beneath the white layer.

Ekmekci, Bülent

2007-09-01

35

Fabrication of 3D Metal Microstructures Using a Hybrid Process of Micro-EDM and Laser Assembly  

Microsoft Academic Search

A fabrication technique for 3D metal microstructures using hybrid process integrated micromachining and welding on a workstation is described in the paper. The system uses a micro-EDM (micro electro-discharge machining) process to fabricate microparts, and Nd-YAG laser welding to microassemble these microparts precisely. A diverse pattern of 3D metal microstructures or micromoulds can be attained via further machining procedures controlled

C.-L. Kuo; J.-D. Huang

2003-01-01

36

Simultaneous Processing Method for Micro-Rods and Holes Using EDM  

NASA Astrophysics Data System (ADS)

This paper describes a new method for micro-EDM drilling which utilizes the wear of rod electrodes. With this method, a pair of micro rod and micro hole can be machined in a single process, while with conventional methods, the micro rod electrode needs to be formed before machining the micro hole. Processing conditions were optimized for the new method to obtain higher aspect ratio for the micro rods. Results of experiments also showed the following: 1) This method can be applied to AISI1045, AISI304 and Kovar and any electrode diameter size. 2) From the second process, if machining many holes using the same electrode, the electrode shape can be regenerated with excellent repeatability and holes processed efficiently. 3) The influence of carbon adhering to the tip region of the rod electrode is large, which is why the rod electrode becomes needle sharp.

Yamazaki, Minoru; Mori, Noritosi; Suzuki, Takemi; Kunieda, Masanori

37

Laser machining in die making—a modern rapid tooling process  

Microsoft Academic Search

Laser machining is a new, very flexible process in mould making especially, for the machining of filigree structures. This process is suitable for machining difficult-to-machine materials, like ceramics, carbide and hardened steel with excellent productivity and surface quality. Laser machining provides a number of advantages over the traditional electro discharge machining (EDM) in die making. It eliminates the expensive manufacture

A. Kaldos; H. J. Pieper; E. Wolf; M. Krause

2004-01-01

38

After 60 years of EDM the discharge process remains still disputed  

Microsoft Academic Search

The ignition of electrical discharges in a dirty, liquid filled gap, when applying EDM, is mostly interpreted as ion action identical as found by physical research of discharges in air (Lichtenberg figures) or in vacuum (radio tubes) as well as with investigations on the breakthrough strength of insulating hydrocarbon liquids. The state of the servo-controlled gap in real ED-machining, however,

Bernd M Schumacher

2004-01-01

39

Demands on process and process energy sources for the electro-erosive and electrochemical micro machining  

Microsoft Academic Search

This article will demonstrate which demands are required from process energy sources (PES), if the non-conventional machining\\u000a procedures EDM (Electrical Discharge Machining) and ECM (Electrochemical Machining) are efficiently used for the micro machining.\\u000a Due to the very low working gap, the process conditions are considerably changed compared to the previous machining conditions.\\u000a The well known PES-concepts can no longer be

H.-P. Schulze; D. Borkenhagen; S. Burkert

2008-01-01

40

Machine and process characterization  

SciTech Connect

A study was conducted to statistically characterize 11 precision machining centers to determine their operating characteristics and process capabilities. Measurement probes and a ball plate were used for measurement analysis. A generic test part designed with geometric features that the department typically manufactures was machined using various machining processes. A better understanding of each machine's characteristics and process capability was realized through repeating these methods on each machine.

Love, L.W.

1992-12-01

41

The Potential of Plating Techniques in the Development of Rapid EDM Tooling  

Microsoft Academic Search

Electrodischarge machining (EDM) is a widely used process in the manufacturing of mould cavities for plastic products. EDM\\u000a work typically accounts for a large portion of overall production time. A major cost and time element of EDM is electrode\\u000a production, which can account for more than 50% of the total machining costs. A large complex electrode profile, which is\\u000a very

F. E. H. Tay; E. A. Haider

2001-01-01

42

Study on an evaluation method of micro CMM spherical stylus tips by µ-EDM on-machine measurement  

NASA Astrophysics Data System (ADS)

This paper describes an on-machine measurement function of a micro electro-discharge machine (µ-EDM) to evaluate the quality of micro ball-ended stylus tips fabricated by a combination of wire-electro-discharge grinding (WEDG) and one-pulse-electro-discharge (OPED) technology. A low-voltage contacting trigger function without any capacitor between a stationary wire and the spindle of a µ-EDM was used to measure the outer profile and evaluate the forming quality. The measurement results show that the deviation of the largest radius between the micro ball-ended tip and stem is approximately 3 µm. Moreover, OPED/WEDG is also easily able to produce high-quality micro spherical stylus tips with a standard deviation as small as 0.7 µm through use of sharp-needle-shaped electrode tools. With further improvements in electro-discharge position, OPED and WEDG technology are promising and excellent approaches for manufacturing micro coordinate measurement machine (CMM) spherical stylus tips.

Sheu, Dong-Yea

2010-07-01

43

Hybrid micromachining using a nanosecond pulsed laser and micro EDM  

NASA Astrophysics Data System (ADS)

Micro electrical discharge machining (micro EDM) is a well-known precise machining process that achieves micro structures of excellent quality for any conductive material. However, the slow machining speed and high tool wear are main drawbacks of this process. Though the use of deionized water instead of kerosene as a dielectric fluid can reduce the tool wear and increase the machine speed, the material removal rate (MRR) is still low. In contrast, laser ablation using a nanosecond pulsed laser is a fast and non-wear machining process but achieves micro figures of rather low quality. Therefore, the integration of these two processes can overcome the respective disadvantages. This paper reports a hybrid process of a nanosecond pulsed laser and micro EDM for micromachining. A novel hybrid micromachining system that combines the two discrete machining processes is introduced. Then, the feasibility and characteristics of the hybrid machining process are investigated compared to conventional EDM and laser ablation. It is verified experimentally that the machining time can be effectively reduced in both EDM drilling and milling by rapid laser pre-machining prior to micro EDM. Finally, some examples of complicated 3D micro structures fabricated by the hybrid process are shown.

Kim, Sanha; Kim, Bo Hyun; Chung, Do Kwan; Shin, Hong Shik; Chu, Chong Nam

2010-01-01

44

Effects of finishing processes on the fatigue life improvements of electro-machined surfaces of tool steel  

Microsoft Academic Search

Machining the EN X160CrMoV12 tool steel by electro-discharge machining (EDM) process generates significant modifications of\\u000a microgeometrical, microstructural and mechanical properties of the upper layers of the machined components. In this paper,\\u000a the role of these modifications in controlling the stability, under cyclic loading, of the propagation of the crack networks\\u000a generated by EDM is discussed. High cycle fatigue tests (2?×?106

Farhat Ghanem; Nabil Ben Fredj; Habib Sidhom; Chedly Braham

2011-01-01

45

Intelligent Modeling and Multi–Objective Optimization of Die Sinking ElectroChemical Spark Machining Process  

Microsoft Academic Search

Die Sinking–Electro Chemical Spark Machining (DS–ECSM) is one of the hybrid machining processes, combining the features of Electro Chemical Machining (ECM) and Electro Discharge Machining (EDM), used for machining of non-conducting materials. This paper reports, an intelligent approach for the modelling of DS–ECSM process using FEM and ANN in integrated manner. It primarily comprises development of two models. First one

Mohan Charan Panda; Vinod Yadava

2011-01-01

46

Intelligent Modeling and Multiobjective Optimization of Die Sinking Electrochemical Spark Machining Process  

Microsoft Academic Search

Die sinking–electrochemical spark machining (DS–ECSM) is one of the hybrid machining processes, combining the features of electrochemical machining (ECM) and electro-discharge machining (EDM), used for machining of nonconducting materials. This article reports an intelligent approach for the modelling of DS–ECSM process using finite element method (FEM) and artificial neural network (ANN) in integrated manner. It primarily comprises development of two

Mohan Charan Panda; Vinod Yadava

2012-01-01

47

Erosion Rate, Surface Finish and Electrode Wear in Electric Discharge Machining (EDM) of Dental Alloys.  

National Technical Information Service (NTIS)

A precise fit of dental restorations is critical in all aspects of prosthetic dentistry. Fabrication of a prosthesis with a high degree of accuracy is difficult due to the dimensional changes of different dental materials. EDM is an extremely accurate non...

G. E. Orraca

1997-01-01

48

Numerical prediction of heat affected layer in the EDM of aeronautical alloys  

NASA Astrophysics Data System (ADS)

Electrical discharge machining is a popular non-traditional machining process, optimum for accurate machining of complex geometries in hard materials. EDM has been used for decades for machining pieces for the aeronautical industry, but surface integrity, and consequently the reliability of the machined parts have been questioned for long time due to the thermal nature of this machining process. In recent years, efforts have been put on modeling of the EDM process, being thermal modeling of the process one promising alternative. In a previous publication an original model of the EDM process was presented and it was used to predict material removal rate and surface finish for the EDM of steel. In the present article the capability of that modeling tool to characterize discharge properties and to predict recast layer distribution when EDMing an aeronautical alloy will be analyzed. EDM process of Inconel 718 has been studied and discharge properties have been obtained for four different EDM regimes. The capability of the model to reflect the behavior of more energetic regimes is discussed. Gathered information has been used to simulate the evolution of the recast layer generation process. Obtained results have been validated comparing them with experimental measurements, revealing a good correlation between predictions and experimental data. Finally, energetic efficiency of the discharge process has been simulated for the adjusted EDM regimes.

Izquierdo, B.; Plaza, S.; Sánchez, J. A.; Pombo, I.; Ortega, N.

2012-10-01

49

Investigation of the effect of process parameters on the formation and characteristics of recast layer in wire-EDM of Inconel 718  

SciTech Connect

Inconel 718 is a high nickel content superalloy possessing high strength at elevated temperatures and resistance to oxidation and corrosion. The non-traditional manufacturing process of wire-electrical discharge machining (EDM) possesses many advantages over traditional machining during the manufacture of Inconel 718 parts. However, certain detrimental effects are also present and are due in large part to the formation of the recast layer. An experimental investigation was conducted to determine the main EDM parameters which contribute to recast layer formation in Inconel 718. It was found that average recast layer thickness increased primarily with energy per spark, peak discharge current, and current pulse duration. Over the range of parameters tested, the recast layer was observed to be between 5 and 9 {micro}m in average thickness, although highly variable in nature. The recast material was found to possess in-plane tensile residual stresses, as well as lower hardness and elastic modulus than the bulk material.

Newton, Thomas R [Georgia Institute of Technology; Melkote, Shreyes N [Georgia Institute of Technology; Watkins, Thomas R [ORNL; Trejo, Rosa M [ORNL; Riester, Laura [ORNL

2009-01-01

50

Nontraditional Machining of Beryllium.  

National Technical Information Service (NTIS)

The report deals with electrichemical machining (ECM), chemical milling, and electric-discharge machining (EDM). The general characteristics of these processes and their applications to the processing of beryllium parts are presented and covered in detail...

J. A. Gurklis

1972-01-01

51

Wire EDM for Refractory Materials  

NASA Technical Reports Server (NTRS)

In an attempt to reduce fabrication time and costs, Wire Electrical Discharge Machine (Wire EDM) method was investigated as tool for fabricating matched blade roots and disk slots. Eight high-strength nickel-base superalloys were used. Computer-controlled Wire EDM technique provided high quality surfaces with excellent dimensional tolerances. Wire EDM method offers potential for substantial reductions in fabrication costs for "hard to machine" alloys and electrically conductive materials in specific high-precision applications.

Zellars, G. R.; Harris, F. E.; Lowell, C. E.; Pollman, W. M.; Rys, V. J.; Wills, R. J.

1982-01-01

52

Fabrication of a miniature diamond grinding tool using a hybrid process of micro-EDM and co-deposition  

NASA Astrophysics Data System (ADS)

A novel miniature diamond grinding tool usable for the precise micro-grinding of miniature parts is presented. A hybrid process that combines 'micro-EDM' with 'precision co-deposition' is proposed. The metal substrate is micro-EDMed to a 50 µm diameter and micro diamonds with 0-2 µm grains are 'electroformed' on the substrate surface, producing a miniature multilayered grinding tool. Nickel and diamond act as binders and cutters, respectively. A partition plate with an array of drilled holes is designed to ensure good convection in the electroforming solution. The dispersion of diamond grains and displacement of nickel ions are noticeably improved. A miniature funnel mould enables the diamond grains to converge towards the cathode to increase their deposition probability on the substrate, thereby improving their distribution on the substrate surface. A micro ZrO2 ceramic ferrule is finely ground by the developed grinding tool and then yields a surface roughness of Ra = 0.085 µm. The proposed approach is applied during the final machining process.

Chen, Shun-Tong; Lai, Yun-Cheng; Liu, Ching-Chang

2008-05-01

53

Ultrasonic Vibration Assisted ElectroDischarge Machining  

Microsoft Academic Search

An ultrasonic vibration has been superposed on the normal electrode movement to increase the flushing effect during a micro electro-discharge machining (EDM) process. A systematic study on the effects of ultrasonic vi- bration on the EDM performance for fabricating microholes in Nitinol has been completed. The introduction of ultrasonic vibration to the micro- EDM process has more than 60 times

H. Huang; H. Y. Zheng

54

Technological Advancement in Electrical Discharge Machining with Powder Metallurgy Processed Electrodes: A Review  

Microsoft Academic Search

Electrical discharge machining (EDM) is a well-established machining option for processing hard materials with complex geometrical shapes which are extremely difficult-to-machine by conventional machining processes. These hard materials find applications where lower surface cracks, wear resistance, corrosion resistance, etc. are desirable surface properties. In recent years, research has been carried out to determine the possibility of employing electrode as feed

Naveen Beri; Sachin Maheshwari; Chitra Sharma; Anil Kumar

2010-01-01

55

EDM and the resulting hydrogen embrittlement of maraging steel  

NASA Astrophysics Data System (ADS)

The use of electrical discharge machining (EDM), or spark erosion as it is sometimes called, introduces hydrogen into maraging steel 250 such that brittle fracture surfaces result from embrittlement accelerated by slow-strain-rate tensile tests. Brittle fracture features indicate potential premature failure due to hydrogen embrittlement. Experimental control was provided by test specimens machined by abrasive waterjet, a machining technique that does not evolve hydrogen as a part of the machining process. Hydrogen concentration measurements indicate the hydrogen concentration of specimens fabricated by EDM is approximately 0.5 ppm, while that of specimens machined by abrasive waterjet is approximately 0.1 ppm. On the basis of constant-load tests, the time to failure of test specimens machined by EDM and loaded to 50% of the yield strength is estimated to be a minimum of 30 years.

Quick, Terrence M.

1993-10-01

56

Effect of the Machining Processes on Low Cycle Fatigue Behavior of a Powder Metallurgy Disk  

NASA Technical Reports Server (NTRS)

A study has been performed to investigate the effect of various machining processes on fatigue life of configured low cycle fatigue specimens machined out of a NASA developed LSHR P/M nickel based disk alloy. Two types of configured specimen geometries were employed in the study. To evaluate a broach machining processes a double notch geometry was used with both notches machined using broach tooling. EDM machined notched specimens of the same configuration were tested for comparison purposes. Honing finishing process was evaluated by using a center hole specimen geometry. Comparison testing was again done using EDM machined specimens of the same geometry. The effect of these machining processes on the resulting surface roughness, residual stress distribution and microstructural damage were characterized and used in attempt to explain the low cycle fatigue results.

Telesman, J.; Kantzos, P.; Gabb, T. P.; Ghosn, L. J.

2010-01-01

57

Ultrasonic Abrasive Removal Of EDM Recast  

NASA Technical Reports Server (NTRS)

Ultrasonic abrasive process removes layer of recast material generated during electrical-discharge machining (EDM) of damper pocket on turbine blade. Form-fitted tool vibrated ultrasonically in damper pocket from which material removed. Vibrations activate abrasive in pocket. Amount of material removed controlled precisely.

Mandel, Johnny L.; Jacobson, Marlowe S.

1990-01-01

58

Electrical-Discharge Machining Of Curved Passages  

NASA Technical Reports Server (NTRS)

Electrical-discharge machining (EDM) used to cut deep hole with bends. EDM process done with articulating segmented electrode. Originally straight, electrode curved as it penetrates part, forming long, smoothly curving hole. After hole cut, honed with slurry to remove thin layer of recast metal created by EDM. Breakage of tools, hand deburring, and drilling debris eliminated.

Guirguis, Kamal S.

1993-01-01

59

Ultrasonic vibration assisted electro-discharge machining of microholes in Nitinol  

Microsoft Academic Search

An ultrasonic vibration has been superposed on the normal electrode movement to increase the flushing effect during a micro electro-discharge machining (EDM) process. A systematic study on the effects of ultrasonic vibration on the EDM performance for fabricating microholes in Nitinol has been completed. The introduction of ultrasonic vibration to the micro-EDM process has increased the machining efficiency more than

H. Huang; H. Zhang; L. Zhou; H. Y. Zheng

2003-01-01

60

Wire EDM Fatigue Study with Application to Multi-Lug Breech Mechanisms.  

National Technical Information Service (NTIS)

A fatigue study was conducted to evaluate wire electrical discharge machining (EDM) as a manufacturing method for the production of the intricate lug geometry on multi-lug breech mechanisms. The wire EDM process produces a thin surface layer of recast mat...

V. J. Olmstead S. Tauscher

1997-01-01

61

Development of a micro-punching machine and study on the influence of vibration machining in micro-EDM  

Microsoft Academic Search

This paper describes the development of a novel micro-punching machine that is capable of producing precision micro-holes. A significant feature of this machine is to fabricate the micro-punch and then the micro-die in the same machine, totally eliminating the eccentricity between the punch and the die when punching is proceeded. By applying vibration machining technique, we can decrease the possibility

Gwo-Lianq Chern; Ying-Jeng Engin Wu; Shun-Feng Liu

2006-01-01

62

Inverse Determination Of Discharge Properties Based On Surface Finish And Material Removal Rate Predictions Using Thermal Multi-Spark Modeling Of The EDM Process  

NASA Astrophysics Data System (ADS)

Electrical Discharge Machining (EDM) is a non-conventional machining process whose thermoelectric nature makes it suitable for the machining of any material, regardless of its hardness and of its brittleness, as long as it conducts electricity. Despite EDM is a popular process in industry, the fact that it involves phenomena of very distinct natures (electrical, thermal, chemical and metallurgical) together with the difficulty inherent to the experimental study of the discharge process, there is a lack of scientific knowledge about it. The present work aims to help in this sense, providing a novel modeling tool capable of simulating discharge superposition, which allows the prediction of surface topographies and temperature fields due to discharges. Based on the comparison between results of simulations (material removal rates and surface topographies) and experimental measurements the discharge process can be characterized using an inverse method. Here, the basis of the developed model will be presented, together with the methodology employed to find out the parameters which define discharge properties. Results obtained with this inverse method have been included.

Izquierdo, B.; Sánchez, J. A.; Plaza, S.; Ortega, N.; Pombo, I.

2009-11-01

63

Numerical study on the splitting of a vapor bubble in the ultrasonic assisted EDM process with the curved tool and workpiece.  

PubMed

Electrical discharge machining (EDM) is a powerful and modern method of machining. In the EDM process, a vapor bubble is generated between the tool and the workpiece in the dielectric liquid due to an electrical discharge. In this process dynamic behavior of the vapor bubble affects machining process. Vibration of the tool surface affects bubble behavior and consequently affects material removal rate (MRR). In this paper, dynamic behavior of the vapor bubble in an ultrasonic assisted EDM process after the appearance of the necking phenomenon is investigated. It is noteworthy that necking phenomenon occurs when the bubble takes the shape of an hour-glass. After the appearance of the necking phenomenon, the vapor bubble splits into two parts and two liquid jets are developed on the boundaries of the upper and lower parts of the vapor bubble. The liquid jet developed on the upper part of the bubble impinges to the tool and the liquid jet developed on the lower part of the bubble impinges to the workpiece. These liquid jets cause evacuation of debris from the gap between the tool and the workpiece and also cause erosion of the workpiece and the tool. Curved tool and workpiece affect the shape and the velocity of the liquid jets during splitting of the vapor bubble. In this paper dynamics of the vapor bubble after its splitting near the curved tool and workpiece is investigated in three cases. In the first case surfaces of the tool and the workpiece are flat, in the second case surfaces of the tool and the workpiece are convex and in the third case surfaces of the tool and workpiece are concave. Numerical results show that in the third case, the velocity of liquid jets which are developed on the boundaries of the upper and lower parts of the vapor bubble after its splitting have the highest magnitude and their shape are broader than the other cases. PMID:22784706

Shervani-Tabar, M T; Seyed-Sadjadi, M H; Shabgard, M R

2013-01-01

64

Micro-EDM for silicon microstructure fabrication  

NASA Astrophysics Data System (ADS)

Currently, most silicon microstructures used in microstructures are produced by photolithographic methods. The reason for this is the well-developed etching technology, used in microelectronics, that has been transferred to the microsystem domain. But since the making of an arbitrary shape or angle on silicon mainly depends on the crystal orientation, some severe limits exist in the production of 3D structures. Electro-discharge machining (EDM) is basically a thermal process. During the EDM process material is removed by electric sparking. It is therefore completely different from etching. In this work, micro-EDM is introduce as a potential approach for solving the above mentioned drawbacks. First, this work presents several testing experiments with different process parameters to investigate the influence of the micro-EDM process on the silicon structure. Main emphasis is put on the surface roughness and on avoiding microcracks generated by the sparking process. It is found that microstructures with a sufficiently low surface roughness and with small microcracks can be produced. The remainder of the work concentrates on making small beam structures, which is a common structure in many microsensor designs. It is found that for a wafer thickness of 650 micrometers , the thinnest beam that can be produced is about 30 micrometers wide. This means that micro-EDM can offer an aspect ratio of 20 in combination with a god dimensional control.

Song, Xiaozhong; Reynaerts, Dominiek; Meeusen, Wim; Van Brussel, Hendrik

1999-03-01

65

Machining Efficiency Evaluation of Cryogenically Treated Copper Electrode in Additive Mixed EDM  

Microsoft Academic Search

The present experimental investigations have been carried to evaluate machining efficiency with additive powder mixed in dielectric fluid of electrical discharge machining on Inconel 718 with copper and cryogenically treated copper electrodes. Experiments have been conducted to study the effect of input parameters viz polarity, type of electrode, peak current, pulse on time, duty cycle, gap voltage, retract distance and

Anil Kumar; Sachin Maheshwari; Chitra Sharma; Naveen Beri

2012-01-01

66

Prediction of Thermal Residual Stresses with a Thermo-physical Model of Electrical Discharge Machining Process  

NASA Astrophysics Data System (ADS)

This paper presents a numerical model of die-sinking electric discharge machining process (EDM) to predict the thermal residual stresses induced during the operation. Nonlinear sequential thermo-mechanical analysis is carried out using finite element method (FEM). It is based on a thermo-physical model of EDM process which considered more realistic assumptions such as Gaussian distribution of heat flux and discharge current and discharge duration based spark radius equation. Results predicted show high temperature gradient zones and the regions of large residual stresses exceeding the material yield strength. The model can be used to study the surface integrity of electric discharge machined surfaces.

Joshi, S. N.; Pande, S. D.

2011-05-01

67

Micro-CT evaluation of in vivo osteogenesis at implants processed by wire-type electric discharge machining.  

PubMed

Titanium surfaces processed by wire-type electric discharge machining (EDM) are microfabricated surfaces with an irregular morphology, and they exhibited excellent in vitro bone biocompatibility. In this study, the efficiency of in vivo osteogenesis on EDM surfaces was investigated by surgically placing screw-shaped EDM-processed and machined-surface implants into the femurs of four Japanese white rabbits. The volume and process of new bone formation were evaluated by an X-ray micro-CT scanner, coupled with histopathological observations at 1, 2, and 4 weeks post-implantation. Before surgical implantation, the surface topography and contact angle of each implant surface were examined. Bone formation increased over time on both implant surfaces, with both implant types yielding statistically equivalent bone volume at 4 weeks post-implementation. However, at 1 week post-implantation, amount of new bone at EDM-processed implant was markedly greater than that at machined-surface implant. Moreover, new bone appeared to initiate directly from the EDM surfaces, while new bone appeared to generate from pre-existing host bone to the machined surfaces. Thus, EDM seemed to be a promising method for surface modification of titanium implants to support enhanced osteogenesis. PMID:22673455

Yamaki, Koichi; Kataoka, Yu; Ohtsuka, Fukunaga; Miyazaki, Takashi

2012-01-01

68

Model of workpiece erosion for electrical discharge machining process  

NASA Astrophysics Data System (ADS)

The previously published step-wise model (SWM) of cold electrodes erosion of electric arc heaters (EAHs) was modified for the calculation of workpiece removal rate (WRR) in electrical discharge machining (EDM) process. Modified model applies both relations the step-wise erosion model and the point heat source erosion model and takes into account the discharge current, the discharge pulse/pause time and thermophysical properties of machined material. The results of calculations show a reasonable agreement with data obtained experimentally by different authors about different materials and conditions.

Sharakhovsky, Leonid I.; Marotta, Aruy; Essiptchouk, Alexei M.

2006-11-01

69

Study of the machining process of nano-electrical discharge machining based on combined atomistic-continuum modeling method  

NASA Astrophysics Data System (ADS)

Nano-electrical discharge machining (nano-EDM) is an attractive measure to manufacture parts with nanoscale precision, however, due to the incompleteness of its theories, the development of more advanced nano-EDM technology is impeded. In this paper, a computational simulation model combining the molecular dynamics simulation model and the two-temperature model for single discharge process in nano-EDM is constructed to study the machining mechanism of nano-EDM from the thermal point of view. The melting process is analyzed. Before the heated material gets melted, thermal compressive stress higher than 3 GPa is induced. After the material gets melted, the compressive stress gets relieved. The cooling and solidifying processes are also analyzed. It is found that during the cooling process of the melted material, tensile stress higher than 3 GPa arises, which leads to the disintegration of material. The formation of the white layer is attributed to the homogeneous solidification, and additionally, the resultant residual stress is analyzed.

Zhang, Guojun; Guo, Jianwen; Ming, Wuyi; Huang, Yu; Shao, Xinyu; Zhang, Zhen

2014-01-01

70

Experimental Study on Influence of Process Variables on Crater Dimensions in Micro- EDM of {gamma}-Titanium Aluminide  

SciTech Connect

In the present work the effect of different dielectric mediums in micro-EDM of {gamma}-Titanium Aluminide alloy have been investigated. Experiments were conducted both in the absence (dry conditions) and in presence of dielectric (EDM oil).Circular craters were produced both in the presence and absence of dielectric fluid using varying micro-EDM process variables i.e. open circuit voltage, discharge capacitance, pulse frequency and pulse-on-time. Over cut was measured from optical microscope images using Image Analyzer software. Influences of process variables and optimal conditions for minimum over cut on crater dimensions were investigated. ANOVA test which shows that capacitance of RC circuit contributes significantly in crater formation followed by pulse frequency. Optical photographs exhibit that over cut are less in air medium compared to oil medium.

Mitra, S.; Paul, G.; Sarkar, S. [Department of Production Engineering, Jadavpur University, Kolkata-700032 (India); Nagahanumaiah [Micro Systems Technology Laboratory, CMERI, Durgapur (India)

2011-01-17

71

Multiple lead-electrical discharge machining  

NASA Astrophysics Data System (ADS)

Multiple lead-electrical discharge machining (ML-EDM) was investigated to develop the capability and demonstrate the feasibility of applying state-of-the-art electrical discharge machining (EDM) to the manufacturing of mechanical hardware. Two parts selected for the machining tests were a titanium component container and a stainless steel valve mounting plate. Numerous combinations of ML-EDM and conventional EDM tests were conducted on each part, and the results were evaluated for comparison. In all test cases, the cutting time savings of ML-EDM surpassed the conventional EDM by as much as 42%, and when compared to numerical control (NC) milling, a 75% reduction was achieved. A dimensional analysis revealed that the ML-EDM and conventional EDM were similar, but when compared to the NC milled parts, the ML-EDM parts were superior. When the surface finish comparisons were evaluated, the ML-EDM part surfaces were considerably better at higher material removal rates than those of the conventional EDM process. The investigation also revealed an important fact concerning the number of parts to be machined in a single setup.

Brockhoff, R. W.

1985-08-01

72

Bacillus subtilis EdmS (formerly PgsE) participates in the maintenance of episomes.  

PubMed

Extrachromosomal DNA maintenance (EDM) is an important process in molecular breeding and for various applications in the construction of genetically engineered microbes. Here we describe a novel Bacillus subtilis gene involved in EDM function called edmS (formerly pgsE). Functional gene regions were identified using molecular genetics techniques. We found that EdmS is a membrane-associated protein that is crucial for EDM. We also determined that EdmS can change a plasmid vector with an unstable replicon and worse-than-random segregation into one with better-than-random segregation, suggesting that the protein functions in the declustering and/or partitioning of episomes. EdmS has two distinct domains: an N-terminal membrane-anchoring domain and a C-terminal assembly accelerator-like structure, and mutational analysis of edmS revealed that both domains are essential for EDM. Further studies using cells of Bacillus megaterium and itsedmS (formerly capE) gene implied that EdmS has potential as a molecular probe for exploring novel EDM systems. PMID:23583563

Ashiuchi, Makoto; Yamashiro, Daisuke; Yamamoto, Kento

2013-09-01

73

Surface finishing of micro-EDM holes using deionized water  

NASA Astrophysics Data System (ADS)

In this paper, with the use of deionized water, a finishing process of micro hole surfaces processed by micro electrical discharge machining (micro-EDM) is investigated. A micro hole is machined by micro-EDM using deionized water as a dielectric fluid. The inner surface of the hole is finished successfully via electrochemical dissolution in deionized water. The effects of finishing conditions such as the resistivity of deionized water, the voltage, the tool rotation and the finishing time on the surface quality and accuracy of the shape were investigated. After a finishing process using deionized water with a resistivity of 2 M? cm, a voltage of 80 V, a tool rotation of 1200 rpm and a finishing time of 6 min, the surface roughness was reduced considerably from 0.225 µm Ra after micro-EDM to 0.066 µm Ra.

Chung, Do Kwan; Shin, Hong Shik; Kim, Bo Hyun; Park, Min Soo; Chu, Chong Nam

2009-04-01

74

Development of a 3D touch trigger probe using micro spherical stylus machining by micro-EDM for micro-CMM  

NASA Astrophysics Data System (ADS)

This study develops a low-cost three-dimensional touch trigger probe for micro-CMM using micro spherical stylus machining by micro-EDM. The tip ball of the stylus, with a diameter smaller than 100 ?m, is made by a micro electro discharge machine with the method of wire electro discharge grinding (WEDG). The current study uses tungsten carbide (WC) as the material for the stylus. Experimental results show that, the tip ball roundness could amount to 2 ?m. Since the tip ball is not easily observable by naked eyes, we designed a micro imaging system to observe the probing in real time. This system is created with modified commercial webcam and microscope. The general design of the touch trigger probe is combined the stylus and suspension structure. When the stylus touches workpiece, it can be determined the time of probe trigger by measuring the motion of suspension structure. The stylus machined by micro-EDM was very fragile and the stylus handle of the tip ball was very thin. Therefore, the stylus handle bends easily that would result in the large measurement error or stylus break when the stylus touched workpiece. In this study we designed a measuring probe using a small chuck and an electrical circuit to measure the probe trigger. When the stylus touches the workpiece, the parallel circuit will switch on immediately and pick up the voltage variation of the resistor. Because the transistor always turns ON, it can avoid the problems of excessive energy and electrical noise.

Chu, Chih-Liang; Chen, Yi-Lin; Tai, Tzu-Yao; Liu, Yun-Hui; Chuang, Cheng-Hsin; Lu, Chin-Tu

2011-08-01

75

Effects of Heat Treatments on the On-Line Service Life of a Press Die Manufactured by W-Edm  

NASA Astrophysics Data System (ADS)

Effects of heat treatments on the on-line service life of a press die manufactured by W-EDM are studied. In this work, four manufacturing processes for a press die are considered: (1) milling and then grinding, (2) wire-cut electric discharge machining (W-EDM), (3) low temperature heat treatment after W-EDM, and (4) high temperature heat treatment after W-EDM. On-line punching experiments for an automobile part of BL646-chain are performed. The amount of wear of the die and punch, roll-over and burnish depth in the punched chain are measured every 1,000 strokes. Overall productivities are carefully compared. Finally, it is concluded that heat treatment after W-EDM for a press die can enhance its on-line service life. Especially, high temperature heat treatment after W-EDM is very attractive as a fast and cheap manufacturing method for a press die.

Choi, Kye-Kwang; Lee, Yong-Shin

76

Research Developments in Additives Mixed Electrical Discharge Machining (AEDM): A State of Art Review  

Microsoft Academic Search

Electrical discharge machining (EDM) is a well-established modern machining process used to manufacture geometrically complex shapes, process hard materials that are extremely difficult to machine by conventional machining processes. This noncontact machining technique is continuously emerging from a mere tool and dies making process to a microscale machining applications. In recent years, researches have emphasized on increasing machining performance coupled

Anil Kumar; Sachin Maheshwari; Chitra Sharma; Naveen Beri

2010-01-01

77

Using ultra thin electrodes to produce micro-parts with wire-EDM  

Microsoft Academic Search

Small-sized tools and parts are gaining importance and share of the total product range Micromachining of Engineering Materials, 2002; Ann. CIRP 49 (2) (2000) 473]. An appropriate manufacturing process to cover the growing need for accurate small tools is electro-discharge-machining with thin wires (W-EDM). Until now only a few scientific works have been dealing with cutting by W-EDM using wires

F. Klocke; D. Lung; D. Thomaidis; G. Antonoglou

2004-01-01

78

Development of fabrication system of prostheses using electric discharge machining.  

PubMed

This paper outlines the principles and uses of electric discharge machining (EDM) in the fabrication of prostheses. The three areas of use of EDM are classified as supplementary use, direct fabrication of crowns and bridges and fabrication of titanium copings using a CAD/CAM process. The problems associated with the use of EDM in each area are discussed and the methods employed to overcome these problems are described. The application of numerically controlled (NC) EDM to prosthodontic work is found to be promising. Further refinement and development are necessary before EDM can be widely accepted as a means of fabricating prostheses. PMID:7921799

Miyazaki, T; Kitamura, M; Hotta, Y; Lee, G

1993-07-01

79

Microelectrode array fabrication by electrical discharge machining and chemical etching.  

PubMed

Wire electrical discharge machining (EDM), with a complementary chemical etching process, is explored and assessed as a method for developing microelectrode array assemblies for intracortically recording brain activity. Assembly processes based on these methods are highlighted, and results showing neural activity successfully recorded from the brain of a mouse using an EDM-based device are presented. Several structures relevant to the fabrication of microelectrode arrays are also offered in order to demonstrate the capabilities of EDM. PMID:15188855

Fofonoff, Timothy A; Martel, Sylvain M; Hatsopoulos, Nicholas G; Donoghue, John P; Hunter, Ian W

2004-06-01

80

A new electrode wear compensation method for improving performance in 3D micro EDM milling  

NASA Astrophysics Data System (ADS)

As one of the non-traditional manufacturing processes, micro electrical discharge machining (EDM) has been widely applied for manufacturing precise and complex microstructures. However, a number of issues remain to be studied before micro EDM can become a reliable processing method. Efforts to get higher machining quality and to improve efficiency have been carried out. The electrode wear compensation method is one of the key factors in micro EDM milling. This paper proposes a new electrode wear compensation method, the combination of the linear compensation method (LCM) and the uniform wear method (UWM), called the CLU method. This approach combines LCM, UWM and the theoretical model. Experimental results indicate that machining performance such as material removal rate, electrode wear ratio and surface roughness using the proposed method has been improved compared to that by the uniform wear method.

Yu, Hui-Lan; Luan, Ji-Jie; Li, Jian-Zhong; Zhang, Yu-Sheng; Yu, Zu-Yuan; Guo, Dong-Ming

2010-05-01

81

A Comparative Study of Different Contour Machining Processes of UNS A92024-T3 Alloy  

NASA Astrophysics Data System (ADS)

The optimisation of a manufacturing process involves, among other factors, the correct selection of the technologies for being applied in the process development. Nowadays, contour/profile milling is commonly used as a previous stage for pre-forming airship structural elements before being plastically deformed. Up to the time, contour milling processes is usually performed by High Speed Machining (HSM). However, currently, non traditional machining processes such as ElectroDischarge Machining (EDM) or Abrasive WaterJet Machining (AWJM) have been considered as alternative processes for being used in contouring of light aeronautical alloys. In this work, a basic study based on surface finish analysis has been developed for comparing the performance of different contouring processes applied on UNS A92024 Al-Cu alloy samples.

Batista, M.; Bienvenido, R.; Díaz, J. E.; Gómez, A.; Salguero, J.; Marcos, M.

2009-11-01

82

Development of a computer assistant programming system for micro\\/nano milling tool fabrication by multi-axis wire EDM  

Microsoft Academic Search

Micro\\/nano milling tools are usually made of ultra hard materials. Wire EDM (electrical discharge machining) may be the best choice to fabricate these tools conveniently and efficiently. For micro\\/nano milling tools with complicated three-dimensional (3D) geometries, manually programming method is not applicable. The CAM (computer-aided manufacturing) systems existing in the market don't take the special WEDM (Wire EDM) processes for

Xiang Cheng; Zhigang Wang; Shigeru Kobayashi; Kazuo Nakamoto; Kazuo Yamazaki

2009-01-01

83

Ultrasonic vibration assisted electro-discharge machining of microholes in Nitinol  

NASA Astrophysics Data System (ADS)

An ultrasonic vibration has been superposed on the normal electrode movement to increase the flushing effect during a micro electro-discharge machining (EDM) process. A systematic study on the effects of ultrasonic vibration on the EDM performance for fabricating microholes in Nitinol has been completed. The introduction of ultrasonic vibration to the micro-EDM process has increased the machining efficiency more than 60 times, without significantly increasing the electrode wear. Numerical simulation reveals that the efficiency improvement is attributed to the strong stirring effect caused by ultrasonic vibration, which results in an excellent flushing in the micro-EDM process.

Huang, H.; Zhang, H.; Zhou, L.; Zheng, H. Y.

2003-09-01

84

Influence of Surface Position along the Working Range of Conoscopic Holography Sensors on Dimensional Verification of AISI 316 Wire EDM Machined Surfaces  

PubMed Central

Conoscopic holography (CH) is a non-contact interferometric technique used for surface digitization which presents several advantages over other optical techniques such as laser triangulation. Among others, the ability for the reconstruction of high-sloped surfaces stands out, and so does its lower dependence on surface optical properties. Nevertheless, similarly to other optical systems, adjustment of CH sensors requires an adequate selection of configuration parameters for ensuring a high quality surface digitizing. This should be done on a surface located as close as possible to the stand-off distance by tuning frequency (F) and power (P) until the quality indicators Signal-to-Noise Ratio (SNR) and signal envelope (Total) meet proper values. However, not all the points of an actual surface are located at the stand-off distance, but they could be located throughout the whole working range (WR). Thus, the quality of a digitized surface may not be uniform. The present work analyses how the quality of a reconstructed surface is affected by its relative position within the WR under different combinations of the parameters F and P. Experiments have been conducted on AISI 316 wire EDM machined flat surfaces. The number of high-quality points digitized as well as distance measurements between different surfaces throughout the WR allowed for comparing the metrological behaviour of the CH sensor with respect to a touch probe (TP) on a CMM.

Fernandez, Pedro; Blanco, David; Rico, Carlos; Valino, Gonzalo; Mateos, Sabino

2014-01-01

85

Investigation on mechanism for electrical discharge machining of carbon fibre composite material  

NASA Astrophysics Data System (ADS)

This paper presents an investigation into the feasibility of using electrodischarge machining (EDM) as a means of machining carbon fiber composite material. Basically, it is found that the EDM process can easily machine the composite material with small current. The presence of nonconducting fibers in the composite material does not affect the machining efficiency. Observations indicate that the nonconducting fibers turn into conducting fibers due to carbonization during the ionization stage.

Wang, Min; Lau, W. S.

1992-11-01

86

Influence of EDM pulse energy on the surface integrity of martensitic steels  

Microsoft Academic Search

Electro-discharge machining (EDM) is essentially a thermal process with a complex metal-removal mechanism, involving the formation of a plasma channel between the tool and workpiece electrodes, resulting in metallurgical transformations, residual tensile stresses and cracking. These properties determine the operational behaviour of the material and can be included in one term: surface integrity. Results of different experimental analysis to characterise

J. C Rebelo; A Morao Dias; D Kremer; J. L Lebrun

1998-01-01

87

Electrical discharge machining of carbon nanomaterials in air: machining characteristics and the advanced field emission applications  

NASA Astrophysics Data System (ADS)

A reliable and precise machining process, electrical discharge machining (EDM), was investigated in depth as a novel method for the engineering of carbon nanomaterials. The machining characteristics of EDM applied to carbon nanomaterials 'in air' were systematically examined using scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM), energy-dispersive x-ray spectroscopy (EDS), x-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. The EDM process turned out to 'melt' carbon nanomaterials with the thermal energy generated by electrical discharge, which makes both the materially and geometrically unrestricted machining of nanomaterials possible. Since the EDM process conducted in air requires neither direct contact nor chemical agents, it protects the carbon nanomaterial workpieces against physical damage and unnecessary contamination. From this EDM method, several advanced field emission applications including 'top-down' patterning and the creative lateral comb-type triode device were derived, while our previously reported study on emission uniformity enhancement by the EDM method was also referenced. The EDM method has great potential as a clean, effective and practical way to utilize carbon nanomaterials for various uses.

Ok, Jong Girl; Kim, Bo Hyun; Chung, Do Kwan; Sung, Woo Yong; Lee, Seung Min; Lee, Se Won; Kim, Wal Jun; Park, Jin Woo; Chu, Chong Nam; Kim, Yong Hyup

2008-02-01

88

Development of a high precision tabletop versatile CNC wire-EDM for making intricate micro parts  

NASA Astrophysics Data System (ADS)

The micro-electrical discharge machining (micro-EDM) process has been proved to be appropriate for making 3D micro parts that are difficult and even impossible to manufacture by other processes. In this paper a high precision tabletop CNC wire electrical discharge machine (wire EDM) designed specifically for machining complex shape micro parts or structures is developed. In the machine developed, a novel micro-wire-cutting mechanism is designed, an approach to control wire tension by magnetic force is proposed and a servo feed control strategy, in accordance with the measured gap voltage, is designed and implemented. To verify the functions and capabilities of the machine developed, several thick micro outer and internal spur gears and rack are machined. It shows that the taper angle along the wall or cavity of a part that appears when other micro-EDM processes are applied can be avoided. A very good dimensional accuracy of 1 µm and a surface finish of Rmax equal to 0.64 µm are achieved. The satisfactory cutting of a miniature 3D pagoda with a micro-hooked structure also reveals that the machine developed is versatile, and can be used as a new tool for making intricate micro parts.

Liao, Yunn-Shiuan; Chen, Shun-Tong; Lin, Chang-Sheng

2005-02-01

89

Microelectro discharge machining as a technology in micromachining  

NASA Astrophysics Data System (ADS)

In recent years, machine facilities for Electro Discharge Machining (EDM) have been dramatically improved. Enormous progress has been obtained with respect to form accuracy and structure precision even in the submicron domain, which qualifies EDM as a technology for microfabrication ((mu) EDM). (Mu) EDM therefore extends the family of existing microtechniques e.g. the LIGA process or silicon surface micromachining. The EDM-technology offers 3D microfabrication of conductive materials independent of their mechanical properties like hardness, brittleness, etc. This capability offers new fields of application for the microfabrication of components made e.g. from stainless steel or titanium. In order to demonstrate the successful application of various (mu) EDM processes components and devices like micro gearwheels, microreactors, micro punching tools and mould inserts for micro injection molding of an optical fiber connector are presented, which have been fabricated by EDM in close cooperation between the Institute of Microtechnology Mainz GmbH and the Swiss EDM-manufacturer AGIE Losone. Based on their know-how the partners aim to optimize (mu) EDM for microfabrication purposes.

Ehrfeld, Wolfgang; Lehr, Heinz; Michel, Frank; Wolf, Andrej; Gruber, Hans-Peter; Bertholds, Axel

1996-09-01

90

Advances in Machining Process Modeling  

NASA Astrophysics Data System (ADS)

Ever increasing speed and affordability of computing resources together with the advances in the modeling techniques made it possible to use the numerical models like finite element method (FEM), to simulate the metal cutting processes numerically. This paper explains the recent technological advances made in the commercial DEFORM™ system to facilitate the modeling of metal cutting process. During the first phase of this work a 2D system has been developed which assumes orthogonal cutting conditions. The second phase of this work has resulted in the development of a modeling system for 3D machining processes with main focus on turning. The modeling tools developed in this project utilize a hybrid procedure including both transient and steady state approaches. Automated remeshing procedure is being used with great success. Multiple coating layers on the insert can be modeled to study their thermal effects. Elastic and thermal response of the insert during the machining process can also be modeled using this system. The Usui's wear model has also been implemented in the system to study the tool wear. The system developed has been validated with various results reported from actual cutting tests and comparisons are found to be reasonably accurate.

Chigurupati, Pavanachand; Jinn, Jong-Tae; Oh, Jin Young; Yin, Yanling; Zhang, Hua; Wu, Wei-Tsu

2004-06-01

91

Designing Steps and Simulation Results of a Pulse Classification System for the Electro Chemical Discharge Machining (ECDM) Process - An Artificial Neural Network Approach  

Microsoft Academic Search

This paper presents the designing steps and simulation results of a pulse classification system for the ECDM process using\\u000a artificial neural networks (ANN). An Electro Discharge Machining (EDM) machine was modified by incorporating an electrolyte\\u000a system and by modifying the control system. Gap voltage and working current waveforms were obtained. By observing the waveforms,\\u000a pulses were classified into five groups.

T. K. K. R. Mediliyegedara; A. K. M. De Silva; D. K. Harrison; J. A. Mcgeough; D. Hepburn

2004-01-01

92

Surface Modification of EDMed Surface with Powder Mixed Fluid  

Microsoft Academic Search

The EDMed surface with metal powder mixed fluid has smaller surface roughness and higher resistance to corrosion because of the diffusion of electrode and\\/or powder materials into the machined surface. In this study, a new surface modification technique is proposed to obtain high surface wear resistance using EDM with powder mixed fluid. Firstly, a coating application of nickel layer on

Y. Uno; A. Okada; S. Cetin

93

A comparative experimental investigation of deep-hole micro-EDM drilling capability for cemented carbide (WC-Co) against austenitic stainless steel (SUS 304)  

Microsoft Academic Search

Microelectro-discharge machining (micro-EDM) has become a widely accepted non-traditional material removal process for machining\\u000a difficult-to-cut but conductive materials effectively and economically. The present study aims to investigate the feasibility\\u000a of machining deep microholes in two difficult-to-cut materials: cemented carbide (WC-Co) and austenitic stainless steel (SUS\\u000a 304) using the micro-EDM drilling. The effect of discharge energy and electro-thermal material properties on

Muhammad Pervej Jahan; Yoke San Wong; Mustafizur Rahman

2010-01-01

94

Development of magneto abrasive flow machining process  

Microsoft Academic Search

Abrasive flow machining (AFM) is a relatively new process among non-conventional machining processes. Low material removal rate happens to be one serious limitation of almost all such processes. Limited efforts have hitherto been directed towards improving the efficiency of these processes so as to achieve higher material removal rates by applying different techniques. This paper discusses the possible improvement in

Sehijpal Singh; H. S. Shan

2002-01-01

95

Metallurgical Effects from Conventional, EDM, and Electrochemical Drilling.  

National Technical Information Service (NTIS)

Poor surface integrity of a small deep hole can serve as an initiation point for failure. The drilling methods evaluated in this study were peck drilling, shaped tube electrolytic machining (STEM drilling) and electric discharge (EDM) drilling. All three ...

J. E. Fuller

1980-01-01

96

Development of CO2 Laser Processing Machine.  

National Technical Information Service (NTIS)

On the basic concept that laser processing will be one of the most important processing methods, the authors have studied various technologies for laser processing and resonators. The laser cutting machine has been recently developed by synthesyzing these...

M. Sueda K. Tanaka H. Yamamoto A. Watanabe K. Fukui

1989-01-01

97

The radon EDM apparatus  

NASA Astrophysics Data System (ADS)

The observation of a permanent electric dipole moment (EDM) at current experimentally accessible levels would provide clear evidence of physics beyond the Standard Model. EDMs violate CP symmetry, making them a possible route to explaining the size of the observed baryon asymmetry in the universe. The Radon EDM Experiment aims to search for an EDM in radon isotopes whose sensitivity to CP-odd interactions is enhanced by octupole-deformed nuclei. A prototype apparatus currently installed in the ISAC hall at TRIUMF includes a gas handling system to move radon from a collection foil to a measurement cell and auxiliary equipment for polarization diagnostics and validation. The features and capabilities of the apparatus are described and an overview of the experimental design for a gamma-ray-anisotropy based EDM measurement is provided.

Tardiff, E. R.; Rand, E. T.; Ball, G. C.; Chupp, T. E.; Garnsworthy, A. B.; Garrett, P.; Hayden, M. E.; Kierans, C. A.; Lorenzon, W.; Pearson, M. R.; Schaub, C.; Svensson, C. E.

2014-01-01

98

Effect of Deep Cryogenic Treatment on Machinability of Titanium Alloy (Ti6246) in Electric Discharge Drilling  

Microsoft Academic Search

Currently there is a vital need for cost effective machining processes for titanium alloys. Electrical discharge machining (EDM) is used quite extensively in machining titanium alloys due to its favorable features and advantages. This paper investigates the effect of deep cryogenic treatment (DCT) on machinability of Ti 6246 alloy in electric discharge drilling (EDD) by conducting experimental investigations on the

Simranpreet Singh Gill; Jagdev Singh

2010-01-01

99

An Adaptive Speed Control System for Micro Electro Discharge Machining  

NASA Astrophysics Data System (ADS)

The integration of the state-of-the-art monitoring and adaptive control technologies can substantially improve the performance of EDM process. This paper reports the development of an adaptive speed control system for micro EDM which demands a higher level of accuracy. Monitoring of the machining state is conducted during the machining process so that the conditions are analysed continuously. Various schemes for the machining state are used for decision making. For instance, upon recognition of abnormal discharges, the developed adaptive speed control system would adjust the electrode feeding speed in an attempt to correct the machining state. Experimental verification shows that the proposed system can improve the machining time by more than 50%. In addition, a more accurate machined feature can be produced as compared to traditional EDM servo control systems.

Yeo, S. H.; Aligiri, E.; Tan, P. C.; Zarepour, H.

2009-11-01

100

Machining time estimation for magnetic abrasive processes  

Microsoft Academic Search

Here we present the magnetic abrasive process which is used to finish and size those workpieces that have been produced using standard machine tools. The process is proved to be very effective in achieving the desired finish size and roundness of the workpieces. We develop an empirical expression to estimate the machining time to produce a workpiece with specified roundness.

G. Z. KREMEN; E. A. ELSAYED; J. L. RIBEIRO

1994-01-01

101

Modeling and analysis of the edge disintegration in the EDM drilling cobalt-bonded tungsten carbide  

Microsoft Academic Search

The characteristic feature of edge disintegration easily appears in the electric discharge machining (EDM) drilling processing\\u000a of cobalt-bonded tungsten carbide (WC-Co). Such tendency reduces the strength against fatigue and results in a poor assembly\\u000a tolerance. The objective of this paper was to present the mathematical models for modeling and analysis of the effects of\\u000a process parameters, including the discharge current,

Nun-Ming Liu; Ko-Ta Chiang; Jenn-Tsong Horng; Chih-Cherng Chen

2010-01-01

102

Micro-Hole Multi-Point Punching System Using Punch and Die Made by EDM  

NASA Astrophysics Data System (ADS)

In this research a multi-point micro punch and die system was developed. The process of electric discharge machining (EDM) was used to produce both the punch and die. The punches were machined from a 5 mm diameter tungsten and a 10 mm diameter tool steel round rods by wire electric discharge machining (WEDM), using a 200 µm diameter wire electrode. The die holes were made using the punch as the electrode. The EDM process of the holes was carried out on a newly developed desktop EDM machine. The punch and die placed on a micro-die set and then on a micro press were used to produce micro-holes using an automatic control system developed for this process. Experiments to produce 50 µm to 67 µm square micro-holes on 50 µm thick aluminum, 30 µm thick copper and 20 µm thick stainless steel foils were conducted. The capabilities of multi-point punching using the tungsten punch and a tool steel punch were examined and tungsten was chosen as the material of choice for making the punch tool. A scanning electron microscope confirmed that the holes produced are clean, and the sheared surfaces smooth. The punch tool showed no signs of deformation or cracks even after repeated punching.

Broomfield, Mark; Mori, Toshihiko; Mikuriya, Teruaki; Tachibana, Kazushi

103

Surface Integrity of Inconel 718 by Wire-EDM at Different Energy Modes  

NASA Astrophysics Data System (ADS)

Inconel alloys including IN 718 alloy are widely used in turbomachinery industry due to their superior mechanical properties. Inconel alloys are very difficult to machine using cutting and grinding. Wire electrical discharge machining (W-EDM) is an alternative process to manufacture complex Inconel parts. However, little research has been done on surface integrity by W-EDMed IN 718. This study focuses on surface integrity of IN 718 by W-EDM at different modes of discharge energy. The results show that the EDMed surface topography shows dominant coral reef microstructures at high energy mode, while random microvoids are dominant at low energy modes. The average roughness can be significantly reduced at low energy mode. A thick white layer is predominantly discontinuous and non-uniform at relative high energy modes. Microvoids are confined within the thick white layers and no microcracks were found in the subsurface. A thin white layer by trim cut at low energy mode becomes continuous, uniform, and is free of voids. Compared to the bulk, white layers have dramatic reduction in microhardness. In addition, surface alloying from wire electrode and water dielectric is obvious in main cut, but it can be minimized in trim cuts.

Li, L.; Wei, X. T.; Guo, Y. B.; Li, W.; Liu, J. F.

2014-05-01

104

Fabrication of a micro-tool in micro-EDM combined with co-deposited Ni SiC composites for micro-hole machining  

NASA Astrophysics Data System (ADS)

This paper presents an in situ process using a micro-tool in micro-electro-discharge-machining combined with co-deposited Ni-SiC composites to drill and finish micro-holes. During the machining process, a micro-tool is fabricated by wire electro-discharge grinding and electrodeposition. The experimental result shows that the suitable parameters obtained for fabricating micro-tools for Ni-SiC composite coatings are a current density of 7 A dm-2, positive ring hole diameter of 5 mm, SiC particle size of 4 µm, SiC particle concentration of 10 g l-1, rotational speed of 15 rpm and surfactant cetyltrimethylammonium bromide concentration of 150 ppm. When using this method, the micro-tool is provided with a smooth Ni layer, uniform particle distribution and suitable particle adhesion quantity. Then, circular micro-holes are machined in high nickel alloy. Scanning electron microscopy micrographs and atomic force microscopy measurements show that micro-grinding can improve the surface roughness from 1.47 µm Rmax to 0.462 µm Rmax.

Hung, Jung-Chou; Wu, Wei-Chieh; Yan, Biing-Hwa; Huang, Fuang-Yuan; Wu, Kun-Ling

2007-04-01

105

The fabrication of a micro-spiral structure using EDM deposition in the air  

Microsoft Academic Search

A novel micromachining method to deposit a micro-3D spiral structure in air using electrical discharge machining (EDM) with a brass electrode was presented. During the deposition process, a 3D spiral structure is obtained only by the feed of the z-axis in the vertical direction. Furthermore, the obtained structure can be formed and repeated stably even in the upside-down direction under

Guanxin Chi; Zhenlong Wang; K. Xiao; Jingzhi Cui; Baidong Jin

2008-01-01

106

Virtual-machine-based GIS symbolize process  

NASA Astrophysics Data System (ADS)

This paper proposed a new GIS symbolize process, called virtual machine based symbolize process. It is a new method to create and share map symbol libraries in different GIS platform by using symbol virtual machine, which screened the difference of the concrete GIS platform, and provide a uniform symbol interface for the GIS symbols designer, thus the symbols made by this method can be used in different GIS platforms, and achieve the same representation results.

Su, Kehua; Zhu, Xinyan

2006-10-01

107

Current State and Prospect of MicroMachining  

Microsoft Academic Search

Micro-machining is a delicate process that requires pinpoint accuracy. Researchers in academia and industry worldwide are striving to develop efficient fabrication techniques for features in ranges of a few micrometers and even nanometers. The current leading micro-machining processes are micro drilling, micro milling, and micro turning, micro EDM, micro USM, micro LBM, micro ECM and LIGA. In this paper, the

Xiaoxia Li; Jiuhe Wang; Wen Li

2007-01-01

108

Some investigations into the electric discharge machining of hardened tool steel using different electrode materials  

Microsoft Academic Search

Electric discharge machining (EDM), a ‘non-traditional machining process’, has been replacing drilling, milling, grinding and other traditional machining operations and is now a well-established machining option in many manufacturing industries throughout the world. Modern ED machinery is capable of machining geometrically complex or hard material components, that are precise and difficult-to-machine such as heat treated tool steels, composites, super alloys,

Shankar Singh; S. Maheshwari; P. C. Pandey

2004-01-01

109

Improvement of laser machining processes  

SciTech Connect

Laser processing versus steel rule die cutting was evaluated using new fixturing to enhance the processing of flexible and rigid materials. Other enhancements in laser processing reduced carbon deposits from Kapton parts. A special multi-use fixture was designed to enhance laser cutting and save on additional fixturing. This is an example of using different techniques in new ways to improve product.

Fialko, R.W.; Harvey, D.K.

1992-02-01

110

Gaussian Processes For Machine Learning  

Microsoft Academic Search

Gaussian processes (GPs) are natural generalisations of multivariate Gaussian ran- dom variables to innite (countably or continuous) index sets. GPs have been applied in a large number of elds to a diverse range of ends, and very many deep theoretical anal- yses of various properties are available. This paper gives an introduction to Gaussian processes on a fairly elementary level

Matthias Seeger

2004-01-01

111

Modelling of overlapping craters in micro-electrical discharge machining  

NASA Astrophysics Data System (ADS)

The availability of theoretical and empirical models to predict the machining performance measures of the micro-electrical discharge machining (micro-EDM) process helps in process optimization. However, assumptions made during model development greatly affect the ability and accuracy of such models in process performance prediction. In this work, a new heat conduction analysis using an expanding circular heat source with time varying heat flux as the thermal loading condition is reported for a single electrical discharge erosion model for micro-EDM. Furthermore, a new approach for predicting the machining performance measures of micro-EDM by considering the effects of multiple discharges is also proposed. The heat conduction analysis allowed the plasma flushing efficiencies (PFEs) in micro-EDM to be determined. For discharge energies of 1.6 µJ, 3.4 µJ and 14.6 µJ, the PFEs at the anode were 19%, 23% and 33%, respectively. In addition, the multiple discharge approach generated lower and upper bounds of Rmax values for micro-EDM, which represents the range of Rmax values that may exist on the machined surface. A comparison with the measured Rmax values of surfaces machined at discharge energies of 3.2, 5.5 and 10.4 µJ showed good agreement, thus validating the proposed multiple discharge approach.

Tan, P. C.; Yeo, S. H.

2008-10-01

112

Modeling and Experimental Investigations of Dry Electrical Discharge Machining (DEDM)  

NASA Astrophysics Data System (ADS)

Paper presents mathematical modeling and practical application of Dry Electrical Discharge Milling (DEDM) process using compressed air as dielectric. A comparison of this machining method with kerosene--based EDM milling is presented. The reported results refer to the experiments on micro--machining with thick--walled electrodes. The advantages and drawbacks of this machining method, within the field of micro-machining are described and discussed.

Skrabalak, Grzegorz; Kozak, Jerzy

2011-10-01

113

Effect of Hole Geometry and Electric-Discharge Machining (EDM) on Airflow Rates Through Small Diameter Holes in Turbine Blade Material.  

National Technical Information Service (NTIS)

The effects of two design parameters, electrode diameter and hole angle, and two machine parameters, electrode current and current-on time, on air flow rates through small-diameter (0.257 to 0.462 mm) electric-discharge-machined holes were measured. The h...

R. P. Cochran S. A. Hippensteele

1980-01-01

114

Multiple Lead-Electrical Discharge Machining. Final Report.  

National Technical Information Service (NTIS)

Multiple lead-electrical discharge machining (ML-EDM) was investigated to develop the capability and demonstrate the feasibility of applying state-of-the-art electrical discharge machining (EDM) to the manufacturing of mechanical hardware. Two parts selec...

R. W. Brockhoff

1985-01-01

115

Machine Learning in Remote Sensing Data Processing  

Microsoft Academic Search

Remote sensing data processing deals with real-life applications with great societal values. For instance urban monitoring, fire detection or flood prediction from remotely sensed multispectral or radar images have a great impact on economical and environmental issues. To treat efficiently the acquired data and provide accurate products, remote sensing has evolved into a multidisciplinary field, where machine learning and signal

Gustavo Camps-Valls; Catedratico A. Escardino

2009-01-01

116

Study of an ultrafine w-EDM technique  

NASA Astrophysics Data System (ADS)

A precision ultrafine w-EDM (wire electrical discharge machining) technique specifically for machining intricate parts and structures is developed in this paper. A thumb-sized and versatile w-EDM device equipped with a complete control system for wire tension (ultrafine tungsten wire of 13 µm diameter) is designed and employed for the study of ultrafine w-EDM. The tension of the wire electrode is controlled by magnetic repulsive force to steady the wire during machining. Ultrafine wire cutting can be conducted in vertical-, horizontal- or slantwise-wire arrangements. Via some experiments, optimal machining conditions including discharge capacitance, feed rate, wire tension and the appropriate design for the w-EDM device are obtained. Two miniature samples including a micro of Taipei's landmark 101 building and a micro relay are fabricated and the feasibility of the proposed approach is verified. It is confirmed that the ultrafine w-EDM technique using an ultrafine tungsten wire of 13 µm was realized successfully.

Chen, Shun-Tong; Yang, Hong-Ye; Du, Chih-Wei

2009-11-01

117

A Study of Optimization of Machining Parameters for Electrical Discharge Machining of Boron Carbide  

Microsoft Academic Search

The correct selection of manufacturing conditions is one of the most important aspects to take into consideration in the majority of manufacturing processes and, particularly, in processes related to electrical discharge machining (EDM) of conductive ceramic materials. It is these conditions that determine such important characteristics as surface roughness, electrode wear, and material removal rate. In this article, a review

I. Puertas; C. J. Luis

2004-01-01

118

Control of manufacturing networks which contain a batch processing machine  

Microsoft Academic Search

We consider the control of a batch processing machine which is part of a larger manufacturing network of machines. Systems consisting of a batch processing machine and one or more unit-capacity machines in tandem are considered. The objective is to minimize the average time that jobs spend in the entire system. We present algorithms to determine the optimal policies for

John J. Neale; Izak Duenyas

2000-01-01

119

Simulation of Fatigue Crack Initiation at Corrosion Pits With EDM Notches.  

National Technical Information Service (NTIS)

Uniaxial fatigue tests were conducted to compare the fatigue life of laboratory produced corrosion pits, similar to those observed in the shuttle main landing gear wheel bolt-hole, and an electro-discharged-machined (EDM) flaw. EDM Jaws are used to simula...

S. W. Smith J. A. Newman R. S. Piascik

2003-01-01

120

Effect of hole geometry and Electric-Discharge Machining (EDM) on airflow rates through small diameter holes in turbine blade material  

NASA Technical Reports Server (NTRS)

The effects of two design parameters, electrode diameter and hole angle, and two machine parameters, electrode current and current-on time, on air flow rates through small-diameter (0.257 to 0.462 mm) electric-discharge-machined holes were measured. The holes were machined individually in rows of 14 each through 1.6 mm thick IN-100 strips. The data showed linear increase in air flow rate with increases in electrode cross sectional area and current-on time and little change with changes in hole angle and electrode current. The average flow-rate deviation (from the mean flow rate for a given row) decreased linearly with electrode diameter and increased with hole angle. Burn time and finished hole diameter were also measured.

Hippensteele, S. A.; Cochran, R. P.

1980-01-01

121

Manufacturing of micro electrodes using ultra sonic aided electrochemical machining  

Microsoft Academic Search

In this study, a two-steps composite processing technology combining WEDG process, ultra sonic, and electrolysis machining is adapted to cut micro electrodes. Rod electrode of diameter 3.0 mm is cut to be 0.15 mm on wire-EDM machine in first step. A faster metal removal rate can be achieved on anode by ultra sonic aided electrolysis machining. The diameter of the

Feng-Tsai Wang; Chen-Siang Hsu; R. F. Shyu; C. T. Ho

2003-01-01

122

Parameter Optimization of Ultrasonic Machining Process Using Nontraditional Optimization Algorithms  

Microsoft Academic Search

The optimum selection of process parameters is essential for advanced machining processes, as these processes incur high initial investment, tooling cost, and operating and maintenance costs. This article presents optimization aspects of an important advanced machining process known as ultrasonic machining (USM). The objective considered is maximization of material removal rate (MRR) subjected to the constraint of surface roughness. The

Ravipudi Venkata Rao; P. J. Pawar; J. P. Davim

2010-01-01

123

Accretion of titanium carbide by electrical discharge machining with powder suspended in working fluid  

Microsoft Academic Search

Abstract A surface modification method,by electrical discharge machining,(EDM) with a green compact,electrode has been studied to make,thick TiC or WC layer. Titanium alloy powder,or tungsten powder,is supplied from the green compact,electrode and adheres on a workpiece,by the heat caused by discharge. To avoid the production process of the green compact electrode, a surface modification method by EDM with powder suspended

Katsushi Furutani; Akinori Saneto; Hideki Takezawa; Naotake Mohri; Hidetaka Miyake

124

Fabrication of a micro-spherical tool in EDM combined with Ni-diamond co-deposition  

NASA Astrophysics Data System (ADS)

This paper demonstrates a novel fabrication process using electro-discharge-machining (EDM) combined with co-deposited Ni-diamond composites to build a unique micro-spherical diamond tool. A micro tool is made by a hybrid process including wire electro-discharge grinding, EDM spherical forming, electrochemical machining and co-deposition. Tungsten carbide material is used as the tool substrate. The influence of EDM spherical forming and co-deposition parameters on the tool geometry is presented. The experimental result shows a unique micro-spherical diamond tool can be successfully built with suitable spherical forming parameters that are a peak current of 3 A, pulse duration of 40 µs and spindle rotational speed of 0 rpm in the air, and in Ni-diamond co-deposition are a current density of 7 A dm-2, diamond particle size of 3 µm, diamond particle concentration of 10 g l-1 and rotational speed of 15 rpm. When using this method, the micro tool has a better geometric shape, uniform particle distribution and suitable particle adhesion quantity. The tool is tested to machine a mold provided with a micro-spherical cavity in a high nickel alloy.

Hung, Jung-Chou; Lien, Shao-Chun; Lin, Jui-Kuan; Huang, Fuang-Yuan; Yan, Biing-Hwa

2008-04-01

125

Micro Electro Discharge Machining of Electrically Nonconductive Ceramics  

NASA Astrophysics Data System (ADS)

EDM is a known process for machining of hard and brittle materials. Due to its noncontact and nearly forceless behaviour, it has been introduced into micro manufacturing and through constant development it is now an important means for producing high-precision micro geometries. One restriction of EDM is its limitation to electrically conducting materials. Today many applications, especially in the biomedical field, make use of the benefits of ceramic materials, such as high strength, very low wear and biocompatibility. Common ceramic materials such as Zirconium dioxide are, due to their hardness in the sintered state, difficult to machine with conventional cutting techniques. A demand for the introduction of EDM to these materials could so far not be satisfied because of their nonconductive nature. At the Chemnitz University of Technology and the Fraunhofer IWU, investigations in the applicability of micro-EDM for the machining of nonconductive ceramics are being conducted. Tests are undertaken using micro-EDM drilling with Tungsten carbide tool electrodes and ZrO2 ceramic workpieces. A starting layer, in literature often referred to as `assisting electrode' is used to set up a closed electric circuit to start the EDM process. Combining carbon hydride based dielectric and a specially designed low-frequency vibration setup to excite the workpiece, the process environment can be held within parameters to allow for a constant EDM process even after the starting layer is machined. In the experiments a cylindrical 120 ?m diameter Tungsten carbide tool electrode and Y2O3- and MgO- stabilized ZrO2 worpieces are used. The current and voltage signals of the discharges within the different stages of the process (machining of the starting layer, machining of the base material, transition stage) are recorded and their characteristics compared to discharges in metallic material. Additionally, the electrode feed is monitored. The influences of the process parameters are analysed with regard to the discharge type, electrode wear and process speed. Using the found parameters, micro geometries can be successfully machined into nonconductive Y2O3- and MgO- stabilized ZrO2 ceramic by means of micro-EDM.

Schubert, A.; Zeidler, H.; Wolf, N.; Hackert, M.

2011-05-01

126

Micro Electro Discharge Machining of Electrically Nonconductive Ceramics  

SciTech Connect

EDM is a known process for machining of hard and brittle materials. Due to its noncontact and nearly forceless behaviour, it has been introduced into micro manufacturing and through constant development it is now an important means for producing high-precision micro geometries. One restriction of EDM is its limitation to electrically conducting materials.Today many applications, especially in the biomedical field, make use of the benefits of ceramic materials, such as high strength, very low wear and biocompatibility. Common ceramic materials such as Zirconium dioxide are, due to their hardness in the sintered state, difficult to machine with conventional cutting techniques. A demand for the introduction of EDM to these materials could so far not be satisfied because of their nonconductive nature.At the Chemnitz University of Technology and the Fraunhofer IWU, investigations in the applicability of micro-EDM for the machining of nonconductive ceramics are being conducted. Tests are undertaken using micro-EDM drilling with Tungsten carbide tool electrodes and ZrO{sub 2} ceramic workpieces. A starting layer, in literature often referred to as 'assisting electrode' is used to set up a closed electric circuit to start the EDM process. Combining carbon hydride based dielectric and a specially designed low-frequency vibration setup to excite the workpiece, the process environment can be held within parameters to allow for a constant EDM process even after the starting layer is machined. In the experiments a cylindrical 120 {mu}m diameter Tungsten carbide tool electrode and Y{sub 2}O{sub 3}- and MgO- stabilized ZrO{sub 2} worpieces are used. The current and voltage signals of the discharges within the different stages of the process (machining of the starting layer, machining of the base material, transition stage) are recorded and their characteristics compared to discharges in metallic material. Additionally, the electrode feed is monitored. The influences of the process parameters are analysed with regard to the discharge type, electrode wear and process speed.Using the found parameters, micro geometries can be successfully machined into nonconductive Y{sub 2}O{sub 3}- and MgO- stabilized ZrO{sub 2} ceramic by means of micro-EDM.

Schubert, A. [Chair Micromanufacturing Technology, Faculty of Mechanical Engineering, Chemnitz University of Technology, 09107 Chemnitz (Germany); Fraunhofer Institute for Machine Tools and Forming Technology IWU, 09126 Chemnitz (Germany); Zeidler, H.; Hackert, M. [Chair Micromanufacturing Technology, Faculty of Mechanical Engineering, Chemnitz University of Technology, 09107 Chemnitz (Germany); Wolf, N. [Fraunhofer Institute for Machine Tools and Forming Technology IWU, 09126 Chemnitz (Germany)

2011-05-04

127

Uniformity enhancement of carbon nanofiber emitters via electrical discharge machining  

NASA Astrophysics Data System (ADS)

A very simple, clean, and effective method based on a reliable machining process called electrical discharge machining (EDM) was introduced in order to enhance the field emission uniformity of carbon nanofibers (CNFs). After an EDM post-treatment, the uniformity of the CNF emitters was clearly improved without contaminations, damages, or crystalline deteriorations of the CNFs. As a result, field emission uniformity was apparently enhanced at a low electric field range, promising that the method can be practical for applications requiring both large size and fine uniformity such as in a backlight unit.

Ok, Jong Girl; Kim, Bo Hyun; Sung, Woo Yong; Chu, Chong Nam; Kim, Yong Hyup

2007-01-01

128

Electrical-Discharge Machining With Additional Axis  

NASA Technical Reports Server (NTRS)

Proposed electrical-discharge-machining (EDM) apparatus uses moveable vertical wire as electrode. Wire positionable horizontally along one axis as it slides vertically past workpiece. Workpiece indexed in rotation about horizontal axis. Because of symmetry of parts, process used to make two such parts at a time by defining boundary between them. Advantages: cost of material reduced, imparts less residual stress to workpiece, and less time spent machining each part when parts produced in such symmetrical pairs.

Malinzak, Roger M.; Booth, Gary N.

1991-01-01

129

The study on the atomic force microscopy base nanoscale electrical discharge machining.  

PubMed

This study proposes an innovative atomic force microscopy (AFM) based nanoscale electrical discharge machining (AFM-based nanoEDM) system which combines an AFM with a self-produced metallic probe and a high-voltage generator to create an atmospheric environment AFM-based nanoEDM system and a deionized water (DI water) environment AFM-based nanoEDM system. This study combines wire-cut processing and electrochemical tip sharpening techniques on a 40-µm thick stainless steel sheet to produce a high conductive AFM probes, the production can withstand high voltage and large current. The tip radius of these probes is approximately 40 nm. A probe test was executed on the AFM using probes to obtain nanoscales morphology of Si wafer surface. The silicon wafer was as a specimen to carry out AFM-base nanoEDM process in atmospheric and DI water environments by AFM-based nanoEDM system. After experiments, the results show that the atmospheric and DI water environment AFM-based nanoEDM systems operate smoothly. From experimental results, it can be found that the electric discharge depth of the silicon wafer at atmospheric environments is a mere 14.54 nm. In a DI water environment, the depth of electric discharge of the silicon wafer can reach 25.4 nm. This indicates that the EDM ability of DI water environment AFM-based nanoEDM system is higher than that of atmospheric environment AFM-based nanoEDM system. After multiple nanoEDM process, the tips become blunt. After applying electrochemical tip sharpening techniques, the tip radius can return to approximately 40 nm. Therefore, AFM probes produced in this study can be reused. PMID:21898457

Huang, Jen-Ching; Chen, Chung-Ming

2012-01-01

130

Magnetic field assisted micro electro-discharge machining  

NASA Astrophysics Data System (ADS)

This paper studies the feasibility of application of a magnetic field to obtain higher aspect ratio micro holes on hardened tool steel using the micro electro-discharge machining (micro EDM) process. The magnetic field has been introduced to improve debris circulation. Implementing magnetic force perpendicular to the electrode's rotational force produces a resultant force that is efficient in transporting debris out of the hole during machining. With the magnetic field assisted micro EDM process a hole depth of 1177 µm is achieved in 360 min in tool steel. This is 26% higher when compared with the conventional micro EDM process under similar working conditions. No significant difference is noticed in the side wall surface roughness values in the two cases.

Yeo, S. H.; Murali, M.; Cheah, H. T.

2004-11-01

131

Fabrication of high-density micro holes by upward batch micro EDM  

NASA Astrophysics Data System (ADS)

A large number of micro holes are needed for biomedical parts, ink-jet nozzles and micro droplet spraying parts. In this study, an inexpensive machining approach for producing a batch of micro holes is proposed. A set of previously introduced w-EDM mechanisms is employed to horizontally cut the batch micro electrodes precisely. Through the process arrangement, the micro electrodes and workpiece are not unloaded, repositioned and re-corrected until all the tasks are completed. The micro workpiece is clamped onto the specially designed jig and moved above the micro electrodes to perform machining of the mass micro holes by upward batch micro EDM. The entire procedure is carried out on a developed multifunctional tabletop CNC machine tool. An array of 400 through holes of the identical sizes is successfully fabricated on a stainless-steel plate with a thickness of 30 µm by using the modified peck-drilling method. Experimental results confirmed that the proposed approach could accelerate the removal of debris, reduce the occurrence of abnormal discharges and decrease the machining time.

Chen, Shun-Tong

2008-08-01

132

Flexible human machine interface for process diagnostics  

SciTech Connect

A flexible human machine interface to design and display graphical and textual process diagnostic information is presented. The system operates on different computer hardware platforms, including PCs under MS Windows and UNIX Workstations under X-Windows, in a client-server architecture. The interface system is customized for specific process applications in a graphical user interface development environment by overlaying the image of the process piping and instrumentation diagram with display objects that are highlighted in color during diagnostic display. Customization of the system is presented for Commonwealth Edison`s Braidwood PWR Chemical and Volume Control System with transients simulated by a full-scale operator-training simulator and diagnosed by a computer-based system.

Reifman, J.; Graham, G.E.; Wei, T.Y.C. [Argonne National Lab., IL (United States); Brown, K.R.; Chin, R.Y. [ComEd Chicago, IL (United States)

1996-05-01

133

Present status of CO 2 laser processing  

Microsoft Academic Search

Processing technology using the laser beam is a new technology that is expected to be actively introduced into production\\u000a lines. This paper discusses the merits of CO2 laser processing compared to low density energy processing that uses gas flames, plasmas and arcs, and other high temperature\\u000a heat sources, such as electron beams and electrical discharge machines (EDM)s. Features and characteristics

Takeshi Araya; Tomio Umino

1991-01-01

134

Numerical study on the hydrodynamic behavior of the dielectric fluid around an electrical discharge generated bubble in EDM  

NASA Astrophysics Data System (ADS)

In the process of EDM, due to the electrical current, very small bubbles are created within the gap. These bubbles are connected to each other and generate a single bubble. The vapor bubble continues to grow until it finally collapses to small bubbles. The bubble behavior can be ascertained on the distribution of the pressure in the dielectric fluid around the bubble. In this paper, velocity fields and pressure distribution in the dielectric fluid around the bubble that is generated in the process of EDM are investigated numerically. The tool and the workpiece are assumed as two parallel rigid boundaries with dielectric liquid between them. The boundary integral equation method is applied for the numerical solution of the problem. This study can lead to better understanding of the bubble importance in the performance of the electrical discharge machining process.

Shervani-Tabar, Mohammad T.; Mobadersany, Nima

2013-09-01

135

From NLP (Natural Language Processing) to MLP (Machine Language Processing)  

Microsoft Academic Search

\\u000a Natural Language Processing (NLP) in combination with Machine Learning techniques plays an important role in the field of\\u000a automatic text analysis. Motivated by the successful use of NLP in solving text classification problems in the area of e-Participation\\u000a and inspired by our prior work in the field of polymorphic shellcode detection we gave classical NLP-processes a trial in\\u000a the special

Peter Teufl; Udo Payer; Guenter Lackner

2010-01-01

136

An artificial neural network approach for pulse classification in electro chemical discharge machining (ECDM) – designing of neural network architecture  

Microsoft Academic Search

This paper presents the pulse classification of the ECDM process using artificial neural networks (ANN). An Electro Discharge Machining (EDM) machine was modified by incorporating an electrolyte system and by modifying the control system. Gap voltage and working current waveforms were obtained. By observing the waveforms, pulses were classified into five groups. A feed forward neural network was trained to

T. K. K. R. Mediliyegedara; Anjali K. M. De Silva; David K. Harrison; J. A. McGeough

2005-01-01

137

Improving Electrical Discharge Machined Surfaces Using Magnetic Abrasive Finishing  

Microsoft Academic Search

A recast layer is invariably present on surfaces produced by electrical discharge machining (EDM). For some metals with high hardness, the recast layer may contain micro-cracks. This damaged layer can affect the service life of the parts produced by this method. This investigation demonstrates that magnetic abrasive finishing (MAF) process using unbonded magnetic abrasives (UMA), can improve the quality of

Biing-Hwa Yan; Geeng-Wei Chang; Jung-Hsien Chang; Rong-Tzong Hsu

2004-01-01

138

An evaluation of spark mobility in electrical discharge machining  

Microsoft Academic Search

Process instability and arcing failure in electrical discharge machining (EDM) are still serious problems in practice especially when high erosion rates are attempted. Most known solutions exhibit significant limit on material removal rate and do not always effectively eliminate the causes. This analysis addresses some basic mechanisms of instability and arcing which have been constantly overlooked. Spark mobility, an essential

Y. F. Luo

1998-01-01

139

An Investigation of the High Speed Machining Process Using a Variable Flow Stress Machining Theory  

Microsoft Academic Search

This article investigates the application of the Oxley modeling approach to high speed machining (HSM) process for gaining a fundamental understanding and performance prediction of this process which is gaining increased popularity due to its many economic and technological advantages such as faster metal removal rates, efficient use of machine tools and, improved surface finish and lower cutting forces. Oxley's

J. A. Arsecularatne; B. Kristyanto; P. Mathew

2004-01-01

140

Analytical approximation of the erosion rate and electrode wear in micro electrical discharge machining  

NASA Astrophysics Data System (ADS)

Theoretical models have been used to predict process performance measures in electrical discharge machining (EDM), namely the material removal rate (MRR), tool wear ratio (TWR) and surface roughness (SR). However, these contributions are mainly applicable to conventional EDM due to limits on the range of energy and pulse-on-time adopted by the models. This paper proposes an analytical approximation of micro-EDM performance measures, based on the crater prediction using a developed theoretical model. The results show that the analytical approximation of the MRR and TWR is able to provide a close approximation with the experimental data. The approximation results for the MRR and TWR are found to have a variation of up to 30% and 24%, respectively, from their associated experimental values. Since the voltage and current input used in the computation are captured in real time, the method can be applied as a reliable online monitoring system for the micro-EDM process.

Kurnia, W.; Tan, P. C.; Yeo, S. H.; Wong, M.

2008-08-01

141

An intelligent pulse classification system for electro-chemical discharge machining (ECDM)—a preliminary study  

Microsoft Academic Search

Electro-chemical discharge machining (ECDM) is a hybrid process which combines features of electro-chemical machining (ECM) and electro-discharge machining (EDM). In order to develop a control strategy for this complex process, a preliminary study of a pulse classification system was carried out. By observing the voltage and current waveforms, pulses were classified in to five groups. A feed-forward neural network was

T. K. K. R. Mediliyegedara; A. K. M. De Silva; D. K. Harrison; J. A. McGeough

2004-01-01

142

Taguchi analysis of surface modification technique using W-Cu powder metallurgy sintered tools in EDM and characterization of the deposited layer  

Microsoft Academic Search

The present study describes an experimental research on surface modification during electrical discharge machining (EDM) by\\u000a depositing a hard layer over the work surface of C-40 grade plain carbon steel using specially prepared powder metallurgy\\u000a compact tools. The investigated process parameters were composition, compaction pressure, sintering temperature, pulse on-time,\\u000a peak–current setting, and duty factor. Measurements of deposited layer thickness, mass

Promod K. Patowari; Partha Saha; Prasanta K. Mishra

2011-01-01

143

Micro Hole Processing Using Electro-Chemical Discharge Machining  

NASA Astrophysics Data System (ADS)

Recently, micro holes processing on glass were focused on chemical and biological filed. Authors focused on Electro-Chemical Discharge Machining (ECDM) to machine micro holes on glass, and developed the ECDM device. This paper reports about feedback circuit for machining-stop system and two-step machining which were developed to reduce the smallest diameter of micro hole. Additionally, the tool electrode of which diameter was 20 µm was produced using Electro-Chemical Machining (ECM). As a result, the diameter of micro hole was reached to 12 µm.

Mochimaru, Yasuhiro; Ota, Minoru; Yamaguchi, Keishi

144

Process modeling for the prediction of surface finish by a micromechanical process: semimagnetic abrasive machining  

Microsoft Academic Search

A comparatively new micromechanical machining process, semi- magnetic abrasive machining which uses magnetic force as a machining pressure has been developed in ISRO\\/IIT recently for the precision finishing of cylindrical components. The process is controllable because the machining pressure is controlled by the current that is input to the coil of solenoid, but it needs the monitoring of the surface

P. Jayakumar; V. Radhakrishnan

1999-01-01

145

Some digital signal processing techniques for induction machines diagnosis  

Microsoft Academic Search

? Abstract - This paper investigates the recent advances on digital signal processing techniques for induction machines diagnosis. Since non-invasive sensors offer a relatively simple and cost effective fault diagnosis, more emphasis is given to stator current analysis rather than vibration or acoustic analysis in induction machines. Here, further interest has been paid on modern signal processing techniques with a

Shahin Hedayati Kia; Humberto Henao; Gerard-Andre Capolino

2011-01-01

146

Simulation of Surface Integrity for Nanopowder-Mixed Dielectric in Micro Electrical Discharge Machining  

NASA Astrophysics Data System (ADS)

The use of powder-mixed dielectric for electrical discharge machining (PMD-EDM) and micro-electrical discharge machining (PMD micro-EDM) has been shown to reduce machined surface roughness and surface defects, such as, recast layer thickness. However, these were mainly empirical studies which had limited capacity to elucidate the physics and characteristics of the PMD-EDM process. In the current study, a new numerical model has been developed to describe the PMD micro-EDM process. The model has taken into account the larger expansion of the plasma channel and reduction in heat flux distributed to the workpiece because of the presence of powder particles. It has been analyzed using finite element methods (FEMs) and based on the multiple discharge approach. The heat source expansion factor due to the presence of powder particles has been estimated to be 1.07 at 0.02 g/L powder concentration. The fraction of heat flux to the workpiece has been found to decrease from 0.24 at 0.02 g/L to 0.11 at 0.2 g/L powder concentration. For model validation, simulated R max and recast layer thickness values were compared with their corresponding measured values. The simulated and measured results varied with the same general trend which suggested that the proposed process model for PMD micro-EDM was fundamentally sound.

Tan, P. C.; Yeo, S. H.

2013-06-01

147

QUALITY-ORIENTED, COMPREHENSIVE MODELLING OF MACHINING PROCESSES  

Microsoft Academic Search

Modelling of machining operations is a key issue in today's manufacturing. Reliable and effective models are needed in order to plan and control machining processes. The paper gives a short overview of modelling approaches frequently used in manufacturing with emphasis on the workpiece quality. Classical, e.g. differential equation-based techniques focus on the special aspects of machining (e.g. cutting forces, temperature,

S. Markos; J. Viharos; L. Monostori

1998-01-01

148

FPGA based failure monitoring system for machining processes  

Microsoft Academic Search

To be adapted in an easy and economical manner to several machining processes is a desired characteristic in any proposed\\u000a tool condition monitoring system so as to detect or avoid failures in machine tools. Many modern rotating machines have a\\u000a servodriver which may, without sensors, acquire a current signal which is directly related to the cutting forces and then\\u000a be

Luis Alfonso Franco-Gasca; René de Jesús Romero-Troncoso; Gilberto Herrera-Ruiz; Rebeca del Rocío Peniche-Vera

2009-01-01

149

Optimization of Abrasive Powder Mixed EDM of Aluminum Matrix Composites with Multiple Responses Using Gray Relational Analysis  

NASA Astrophysics Data System (ADS)

Abrasive powder-mixed electrical discharge machining (APM-EDM), a hybrid manufacturing process involving the use of a dielectric fluid mixed with abrasive powder, combines the benefits of mechanical and thermal interactions. The aim of this article is to use a new approach of performance evaluation, gray relational analysis (GRA), to evaluate the effectiveness of optimizing multiple performance characteristics of APM-EDM of 6061Al/Al2O3p/20p aluminum matrix composites (AMCs). The considered process parameter includes the seven control factors namely pulse current (A), pulse ON time (?s), duty cycle (%), gap voltage (V), time interval of tool lift (s), abrasive powder concentration (g/L), abrasive particle size (?m), and a noise factor, aspect ratio (shape of tool electrode). The combination of L18 (21 × 37) orthogonal array design of experiment with GRA enables to determine the optimal parameters for multiple responses. GRA is used to obtain a single performance index, gray relational grade through gray relational coefficient to optimize the APM-EDM process with lower tool wear rate, surface roughness, and higher material removal rate. In addition, analysis of variance (ANOVA) for the GRC is also utilized.

Singh, S.; Yeh, M. F.

2012-04-01

150

Analysis on Geometrical Accuracy of Microhole during Micro-EDM of Ti-6Al-4V using Different Dielectrics  

NASA Astrophysics Data System (ADS)

The present study attempts to make comparative investigation of microhole machining process in EDM for using three different dielectrics such as pure kerosene, pure de-ionized water and boron carbide mixed kerosene and de-ionized water. The two most important process parameters i.e. peak current and pulse-on-time were varied keeping other parameters as constant. The experimental results revealed that B4C mixed dielectrics result in non-uniformly circular microholes compared to pure kerosene and de-ionized water. Moreover, when de-ionized water is used, powder mixed dielectric results in generation of accurate microhole with respect to taperness and circularity.

Kibria, G.; Bhattacharyya, B.

2011-01-01

151

Spacing roughness parameters study on the EDM of silicon carbide  

Microsoft Academic Search

In this work, a surface roughness study on the die-sinking electrical discharge machining (EDM) of siliconised or reaction-bonded silicon carbide (SiSiC) has been carried out. The selection of the above-mentioned conductive ceramic was made taking into account its wide range of applications in the industrial field: high-temperature gas turbines, bearings, seals and lining of industrial furnaces. This study was made

I. Puertas; C. J. Luis; G. Villa

2005-01-01

152

Edme Mariotte and Newton's Cradle  

ERIC Educational Resources Information Center

The first recorded experiments describing the phenomena made popular by Newton's cradle appear to be those conducted by Edme Mariotte around 1670. He was quoted in Newton's "Principia," along with Wren, Wallis, and Huygens, as having conducted pioneering experiments on the collisions of pendulum balls. Each of these authors concluded that momentum…

Cross, Rod

2012-01-01

153

Rapid prototyping of zirconium diboride/copper electrical discharge machining electrodes  

NASA Astrophysics Data System (ADS)

The acceptance of rapid prototyping (RP) as the predominant technique for producing polymer and paper parts directly from computer-aided design (CAD) models has led many corporations and universities to try to extend its capabilities to more robust materials. In addition to producing prototype metal and ceramic parts, a significant effort has been made to create parts that are useful as tools and dies or that reduce the time necessary to create tools and dies. Most materials used for tools and dies are very hard, because they need to be able to withstand millions of cycles before failing. Electrical discharge machining (EDM) is the most common method used to machine tools and dies out of hard materials. A method for producing EDM electrodes using RP could greatly reduce the time and cost involved in creating tools and dies. A new EDM electrode material made up of zirconium diboride and copper (ZrBsb2/Cu) that is superior to traditional EDM electrodes has been investigated. The processing techniques necessary for creating Zrsb2/Cu electrodes from powders of ZrB2 and copper have been developed. These ZrBsb2/Cu electrodes have a better wear ratio and a faster sink rate than graphite, copper or tungsten/copper EDM electrodes. Performance variables that were tracked are: (1) wear ratio, (2) sink rate and (3) surface finish, where ZrBsb2/Cu, copper, graphite and W/Cu were used as anodes (electrodes) and stainless steel as cathodes (workpieces). The ZrBsb2/Cu electrode material system retains its superior EDM electrode performance across a number of materials processing and compositional variations. Scanning electron microscopy (SEM) was used to study the electrodes after EDM. These SEM observations facilitated an understanding of the superior EDM electrode performance characteristics of ZrBsb2/Cu to traditional EDM electrode material systems. A method for creating geometrically-complex ZrBsb2/Cu EDM electrodes using the selective laser sintering (SLS) RP technique was developed. Polymer coated ZrBsb2 powders are processed in a SLS machine to produce the desired geometry. Subsequent polymer burnout, sintering of the ZrBsb2 and copper infiltration are performed in a high-temperature furnace.

Stucker, Brent Eric

154

Reducing Indoor Air Emissions from Dry-Process Photocopy Machines.  

National Technical Information Service (NTIS)

The paper discusses reducing indoor air emissions from dry-process photocopy machines. These emissions include: volatile organic compounds (VOCs), ozone, and particles. By measuring emissions in a large test chamber, reviewing the literature, and interact...

K. W. Leovic C. M. Northeim J. A. Calcagni L. S. Sheldon D. A. Whitaker

1997-01-01

155

A neural network process model for abrasive flow machining operations  

Microsoft Academic Search

This paper describes the development of a predictive process modeling system for the abrasive flow machining (AFM) process. This process is used for polishing and surface removal of workpieces with an internal flow path. The core of the process modeling system is a set of neural network models that predicts surface finish and dimensional change. These neural network models are

Kimberly L. Petri; Richard E. Billo; Bopaya Bidanda

1998-01-01

156

Simulation of Fatigue Crack Initiation at Corrosion Pits With EDM Notches  

NASA Technical Reports Server (NTRS)

Uniaxial fatigue tests were conducted to compare the fatigue life of laboratory produced corrosion pits, similar to those observed in the shuttle main landing gear wheel bolt-hole, and an electro-discharged-machined (EDM) flaw. EDM Jaws are used to simulate corrosion pits during shuttle wheel (dynamometer) testing. The aluminum alloy, (AA 7050) laboratory fatigue tests were conducted to simulate the local stress level contained in the wheel bolt-hole. Under this high local stress condition, the EDM notch produced a fatigue life similar to test specimens containing corrosion pits of similar size. Based on the laboratory fatigue test results, the EDM Jaw (semi-circular disc shaped) produces a local stress state similar to corrosion pits and can be used to simulate a corrosion pit during the shuttle wheel dynamometer tests.

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

2003-01-01

157

Surface treatment by electric discharge machining of Ti-6Al-4V alloy for potential application in orthopaedics.  

PubMed

This study investigated the properties of Ti-6Al-4V alloy after surface treatment by the electric discharge machining (EDM) process. The EDM process with high peak currents proved to induce surface macro-roughness and to cause chemical changes to the surface. Evaluations were made of the mechanical properties by means of tensile tests, and of surface roughness for different peak currents of the EDM process. The EDM process with peak current of 29 A was found to induce sufficient surface roughness, and to have a low adverse effect on tensile properties. The chemical changes were studied by scanning electron microscopy equipped with an energy dispersive X-ray analyser (EDX). The surface of the benchmark samples was obtained by plasma-spraying a titanium dioxide coating. An investigation of the biocompatibility of the surface-treated Ti-6Al-4V samples in cultures of human osteoblast-like MG 63 cells revealed that the samples modified by EDM provided better substrates for the adhesion, growth and viability of MG 63 cells than the TiO2 coated surface. Thus, EDM treatment can be considered as a promising surface modification to orthopaedic implants, in which good integration with the surrounding bone tissue is required. PMID:22340689

Harcuba, Petr; Ba?áková, Lucie; Stráský, Josef; Ba?áková, Markéta; Novotná, Katarína; Jane?ek, Miloš

2012-03-01

158

Optimization of process parameters of mechanical type advanced machining processes using genetic algorithms  

Microsoft Academic Search

Generally, unconventional or advanced machining processes (AMPs) are used only when no other traditional machining process can meet the necessary requirements efficiently and economically because use of most of AMPs incurs relatively higher initial investment, maintenance, operating, and tooling costs. Therefore, optimum choice of the process parameters is essential for the economic, efficient, and effective utilization of these processes. Process

Neelesh K. Jain; V. K. Jain; Kalyanmoy Deb

2007-01-01

159

Machine Learning for Intelligent Processing of Printed Documents  

Microsoft Academic Search

A paper document processing system is an information system component which transforms infor- mation on printed or handwritten documents into a computer-revisable form. In intelligent systems for paper document processing this information capture process is based on knowledge of the specific layout and logical structures of the documents. This article proposes the application of machine learning techniques to acquire the

Floriana Esposito; Donato Malerba; Francesca A. Lisi

2000-01-01

160

Machine Learning for Intelligent Processing of Printed Documents  

Microsoft Academic Search

A paper document processing system is an information system component which transforms information on printed or handwritten documents into a computer-revisable form. In intelligent systems for paper document processing this information capture process is based on knowledge of the specific layout and logical structures of the documents. This article proposes the application of machine learning techniques to acquire the specific

Floriana Esposito; Donato Malerba; Francesca A. Lisi

2000-01-01

161

An experimental study of electrochemical polishing for micro-electro-discharge-machined stainless-steel stents.  

PubMed

This paper reports electrochemical polishing (EP) of 316L stainless-steel structures patterned using micro-electro-discharge machining (?EDM) for application to stents including intelligent stents based on micro-electro-mechanical-systems technologies. For the process optimization, 10 ?m deep cavities ?EDMed on the planar material were polished in a phosphoric acid-based electrolyte with varying current densities and polishing times. The EP condition with a current density of 1.5 A/cm(2) for an EP time of 180 s exhibited the highest surface quality with an average roughness of 28 nm improved from~400 nm produced with high-energy ?EDM. The EP of ?EDMed surfaces was observed to produce almost constant smoothness regardless of the initial roughness determined by varying discharge energies. Energy-dispersive X-ray spectroscopy was performed on the ?EDMed surfaces before and after EP. A custom rotational apparatus was used to polish tubular test samples including stent-like structures created using ?EDM, demonstrating uniform removal of surface roughness and sharp edges from the structures. PMID:22183790

Lappin, Derry; Mohammadi, Abdolreza Rashidi; Takahata, Kenichi

2012-02-01

162

Study of the Diffusion of Carbon, Its Sources, and Effect on Finishing Micro-EDM Performance of Cemented Carbide  

NASA Astrophysics Data System (ADS)

Apart from the necessity of surface modification based on different applications, in most of the cases, diffusion of carbon or foreign particles on the workpiece surface during micro-electrodischarge machining (micro-EDM) is avoidable, especially in finishing micro-EDM. This study aims to investigate different sources of materials that migrate to the machined surface during fine-finishing of micro-EDM of cemented tungsten carbide (WC-Co). The machined surfaces have been examined under scanning electron microscope and energy dispersive x-ray to investigate the changes in chemical composition. It has been observed that during finishing of micro-EDM, the major source of materials' transfer to both the workpiece and electrode is the diffusion of carbon that comes from the decomposition of the hydrocarbon dielectric. In addition, materials from both workpiece and electrode transfer to each other based on machining conditions and discharge energy. The migration occurs more frequently at lower gap voltages during die-sinking with micro-EDM because of low spark gap and stationary tool electrode. Milling micro-EDM results in lower amount of carbon migration and fewer surface defects that improve the overall surface finish significantly.

Jahan, M. P.; Rahman, M.; Wong, Y. S.

2012-08-01

163

Mining process control data using machine learning  

Microsoft Academic Search

Manufacturing process data collected over time are considered time-series data and can be arranged into control charts. Important applications can be centered around these data like, for example, recognition of specific patterns, pattern similarity, detecting anomalies, and clustering and classification of patterns. We study and evaluate a number of classification techniques for process control data. For pattern similarity, we examine

Emad S. Abouel Nasr; Hisham AI-Mubaid

2009-01-01

164

Soviet Patent Bulletin Processing: A Particular Application of Machine Translation.  

ERIC Educational Resources Information Center

Describes some of the processes involved in the data structure manipulation and machine translation of a specific text form, namely, Soviet patent bulletins. The effort to modify this system in order to do specialized processing and translation is detailed. (Author/SED)

Bostad, Dale A.

1985-01-01

165

Electric dipole moments (EDM) of ionic atoms  

SciTech Connect

Recent investigations show that the second-order perturbation calculations of electric dipole moments (EDM) from the finite nuclear size as well as the relativistic effects are all canceled out by the third-order perturbation effects and that this is due to electron screening. To derive the nucleon EDM from the nucleus, we propose to measure the EDM of an ionic system. In this case, it is shown that the nucleon EDM can survive by the reduction factor of 1/Z for the ionic system with one electron stripped off.

Oshima, Sachiko [Department of Physics, Faculty of Science and Technology, Nihon University, Tokyo (Japan)

2010-03-15

166

Material modeling and high-speed machining process  

SciTech Connect

Orthogonal machining experiments have been conducted at moderate speeds with 6061-T6 aluminum and Ti-6Al-4V titanium alloys to measure strain distributions in the deformed chip, using a grid technique. While the aluminum alloy displayed large uniform strain within continuous chips, the titanium alloy exhibited highly nonuniform strain distributions within segmented chips, a feature known to occur under high-speed machining. Concurrently, a set of simple constitutive equations are formulated in order to describe the plastic flow behavior of materials over wide ranges of strain, strain rate and temperature. Based on experimental data, the proposed form of constitutive equation is capable of simulating stress-strain-strain rate relationships of 6061-T6 aluminum and Ti-6Al-4V over the range of strain rates applicable to the high-speed machining process. Given the constitutive relations, analytical problems that will be encountered in modeling the localized shear process are outlined based on the experimental observations of chip formation. As a step toward modeling the high-speed machining process, a partially successful finite element analysis of a simplified, continuous chip orthogonal machining process was made using the ADINA code. Some of the relevant analytical and experimental results that have been obtained for the aluminum and titanium alloys are examined. 47 references, 14 figures.

Lee, D.; Wilkening, W.W.

1982-10-01

167

The fabrication of a micro-spiral structure using EDM deposition in the air  

NASA Astrophysics Data System (ADS)

A novel micromachining method to deposit a micro-3D spiral structure in air using electrical discharge machining (EDM) with a brass electrode was presented. During the deposition process, a 3D spiral structure is obtained only by the feed of the z-axis in the vertical direction. Furthermore, the obtained structure can be formed and repeated stably even in the upside-down direction under a gravity environment. It is seen that the material components of a micro-spiral structure are almost the same as those of an electrode by the energy spectrum analysis of a micro-spiral structure. According to scanning electron microscope photographs, the micro-spiral appears to feature a layered material organism structure and has compact bonding with the body material. In order to understand the forming mechanism of this kind of micro-spiral structure, simulation analysis is conducted. The track of the deposition particles can be obtained by simulation, which determines the shape of the deposited structure. According to the simulation results, the track of the deposition particles is consistent with that of EDM experiments. It is further found that the distribution of the electromagnetic field in a discharge channel has an important influence on the deposited structure and the track of the deposition particles.

Chi, Guanxin; Wang, Zhenlong; Xiao, K.; Cui, Jingzhi; Jin, Baidong

2008-03-01

168

An experimental study on micro-EDM in low-resistivity deionized water using short voltage pulses  

Microsoft Academic Search

Deionized water has been used as dielectric fluid for micro-electrical discharge machining (micro-EDM) because it gives higher\\u000a material removal rate and lower tool wear than hydrocarbon oil. Moreover, it is a relatively low-cost and eco-friendly substance.\\u000a Therefore, deionized water tends to be more favorable for micro-EDM. However, it causes weak electrochemical reaction during\\u000a micro-EDM due to its slight conductivity. This

Minh Dang Nguyen; Mustafizur Rahman; Yoke San Wong

169

Signal-Processing Machines at the Postsynaptic Density  

NASA Astrophysics Data System (ADS)

Dendrites of individual neurons in the vertebrate central nervous system are contacted by thousands of synaptic terminals relaying information about the environment. The postsynaptic membrane at each synaptic terminal is the first place where information is processed as it converges on the dendrite. At the postsynaptic membrane of excitatory synapses, neurotransmitter receptors are attached to large protein ``signaling machines'' that delicately regulate the strength of synaptic transmission. These machines are visible in the electron microscope and are called the postsynaptic density. By changing synaptic strength in response to neural activity, the postsynaptic density contributes to information processing and the formation of memories.

Kennedy, Mary B.

2000-10-01

170

Combination of electric discharge machining and laser ablation in microstructuring of hardened steels  

Microsoft Academic Search

Improving the efficiency of manufacturing processes becomes more and more important. This paper describes a new approach where\\u000a two technologies are combined to manufacture wear-resistant mold inserts for powder injection molding. By combining laser\\u000a ablation and electrical discharge machining (EDM) specific advantages of the respective technology can be utilized while drawbacks\\u000a can partially be eliminated.\\u000a \\u000a In the following machining results

J. Fleischer; J. Schmidt; S. Haupt

2006-01-01

171

Controlled English to facilitate human/machine analytical processing  

NASA Astrophysics Data System (ADS)

Controlled English is a human-readable information representation format that is implemented using a restricted subset of the English language, but which is unambiguous and directly accessible by simple machine processes. We have been researching the capabilities of CE in a number of contexts, and exploring the degree to which a flexible and more human-friendly information representation format could aid the intelligence analyst in a multi-agent collaborative operational environment; especially in cases where the agents are a mixture of other human users and machine processes aimed at assisting the human users. CE itself is built upon a formal logic basis, but allows users to easily specify models for a domain of interest in a human-friendly language. In our research we have been developing an experimental component known as the "CE Store" in which CE information can be quickly and flexibly processed and shared between human and machine agents. The CE Store environment contains a number of specialized machine agents for common processing tasks and also supports execution of logical inference rules that can be defined in the same CE language. This paper outlines the basic architecture of this approach, discusses some of the example machine agents that have been developed, and provides some typical examples of the CE language and the way in which it has been used to support complex analytical tasks on synthetic data sources. We highlight the fusion of human and machine processing supported through the use of the CE language and CE Store environment, and show this environment with examples of highly dynamic extensions to the model(s) and integration between different user-defined models in a collaborative setting.

Braines, Dave; Mott, David; Laws, Simon; de Mel, Geeth; Pham, Tien

2013-06-01

172

Physico-Mathematical Analysis of the Electro Discharge Machining Process.  

National Technical Information Service (NTIS)

Calculation methods were developed for simulating the different phenomena occuring in EDM sparks and for determining the volume of metal melted per pulse and the volume of metal removed per pulse. This is to predict on a theoretical base the dependent par...

F. Vandijck

1974-01-01

173

In-process machine tool vibration cancellation using PMN actuators  

NASA Astrophysics Data System (ADS)

At present, the machine tool technology in the US is not in the state-of-the-art of leading international competitors. Conventional machine tools under use are being pushed into their machining accuracy limits. There is a pressing need calling for revitalizing the machine tool industry. This paper presents, a mechatronic system developed for reducing tool vibration during machining. It consists of electrical and mechanical components, and is realized by placing electrically driven electrostrictive actuators in a specially designed tool post mechanical structure. The linear neural network controller, namely, digital filters, are implemented using a signal processing board. The experimental investigation is conducted in two stages. In the first stage, a test bed is established to use an electro-magnetic shaker to resemble the excitation of cutting force acting on the tool. In the second stage, experiments were conducted using a lathe on the shop floor. In-process vibration cancellation was observed. In the laboratory experiment, a percent reduction in the 90 percent was possible using a feedforward scheme. The improvement in surface roughness during the turning operation was confirmed from measurements of surface roughness profiles.

Eshete, Zelalem; Zhang, Guangming

1996-12-01

174

Measurement of Temperature Transients in the Electrochemical Discharge Machining Process  

Microsoft Academic Search

The electrochemical discharge machining (ECDM) process is described, along with applications, and the results of the experimental studies are presented. The authors' experimental set-up is described, and data from original measurements of synchronized time varying current and temperature are presented. The mechanism which produces the discharge and removes the material is clearly described and evaluated.

Anjali Kulkarni; R. Sharan; G. K. Lal

2003-01-01

175

Measurement of Temperature Transients in the Electrochemical Discharge Machining Process  

NASA Astrophysics Data System (ADS)

The electrochemical discharge machining (ECDM) process is described, along with applications, and the results of the experimental studies are presented. The authors' experimental set-up is described, and data from original measurements of synchronized time varying current and temperature are presented. The mechanism which produces the discharge and removes the material is clearly described and evaluated.

Kulkarni, Anjali; Sharan, R.; Lal, G. K.

2003-09-01

176

Automotive parts produced by optimizing the process flow forming – machining  

Microsoft Academic Search

Due to the increasing demand for precision parts with high volumes for the automotive industry, the forming of steel has gained increasing substantial importance. Therefore, new manufacturing methods and practices for special parts have been developed with cold, warm, hot and combination forging processes. Furthermore, the demand for assemble-ready parts has largely increased, whereby a subsequent machining operation is now

H. Nägele; H. Wörner; M. Hirschvogel

2000-01-01

177

Machine Vision Systems for Processing Hardwood Lumber and Logs  

Microsoft Academic Search

Machine vision and auto- mated processing systems are under development at Virginia Tech Univer- sity with support and cooperation from the USDA Forest Service. Our goals are to help U.S. hardwood producers automate, reduce costs, increase prod- uct volume and value recovery, and market higher value, more accurately graded and described products. Any vision system is composed of two bread

Philip A. Araman; Daniel L. Schmoldt; Tai-Hoon Cho; Dongping Zhu; Richard W. Conners; D. Earl Kline

1992-01-01

178

ACOUSTIC EMISSION AND MACHINING - PROCESS ANALYSIS AND CONTROL  

Microsoft Academic Search

A quantitative model considering signal attenuation and tool flank wear is proposed to describe the influence of machining process parameters on the level of acoustic emission (AE) generation. The AE sensitivities to width of cut, feed rate, and hardness of material in three-dimensional cutting are experimentally studied. The application of AE signal analysis to chip formation detection, providing information for

Ming-Shong Lan; David A. Dornfeld

1986-01-01

179

A die-scale micromachining process for bulk PZT and its application to in-plane actuators  

Microsoft Academic Search

Bulk ceramics (including PZT) are important materials for electronic and microsystem packaging or device applications, but they are usually difficult to pattern lithographically. A fabrication process combining lithography, electroplating, batch mode micro electro-discharge machining (?EDM) and batch mode micro ultrasonic machining (?USM), LEEDUS, has been developed to provide die-scale pattern transfer capability from lithographic masks onto ceramics, glass or other

Tao Li; Yogesh B. Gianchandani

2005-01-01

180

Temperature Distribution Measurement in EDM Arc Plasma Using Spectroscopy  

NASA Astrophysics Data System (ADS)

This paper describes the measurement of temperature distribution in EDM arc plasma using spectroscopic analysis. The temperature distribution measurement was achieved by using a lens system to magnify the image of the plasma and a mask to limit the plasma region to be observed. The fluxes of two different wavelength spectra radiated from the arc plasma were measured simultaneously with optical fibers and photomultipliers, after which the temperature distribution was computed from the radiant fluxes using the line pair method and Ablel's inversion. Also, the influences of machining conditions, such as electrode shape, gap distance and discharge current, on the temperature distribution were investigated.

Natsu, Wataru; Ojima, Satoyuki; Kobayashi, Teruki; Kunieda, Masanori

181

A miniaturized EDM device suitable to fixing on a robot  

NASA Astrophysics Data System (ADS)

A miniaturized EDM (Electro Discharge Machining) device has been designed which is suitable to fixing on robot, and the whole system can motion mobile working. A novel control strategy of differential driving principle has been presented in order to solve the problem that electrode can't be revolved owing compact size has been resolved. Coaxial forced vibration of electrode is benefit for the evacuation of debris, and it helps to achieve stable and efficient machining. Analysis of harmonic response and the theoretical value of amplitude have been carried out. The optimal design of ultrasonic motor has been implemented using animate function of ANSYS and optimal design means, and the interference between teeth of stator has been avoided. Auto-frequency tracking has been completed, and electrode lateral vibration of electrode has been eliminated. Finally, the holes with figures of ?85?m circle, Y have been machined.

Tang, Yongjun; Guo, Zhongning; Zhang, Yongjun

2007-10-01

182

Deburring microfeatures using micro-EDM  

Microsoft Academic Search

Demands for miniature components are rapidly increased in the field of optics, electronics, and medicine. Various machining methods have been introduced for the fabrication of complex three-dimensional microfeatures. However, burrs, which are an undesired but unavoidable by-product of most machining processes, cause many problems in assembly, inspection, process automation, and precision component operation. Moreover, as feature sizes decrease, burr problems

Young Hun Jeong; Byung HanYoo; Han Ul Lee; Byung-Kwon Min; Dong-Woo Cho; Sang Jo Lee

2009-01-01

183

3D microstructuring of Pyrex glass using the electrochemical discharge machining process  

Microsoft Academic Search

Electrochemical discharge machining (ECDM) is demonstrated to be a potential process for 3D microstructuring of Pyrex glass. However, the key to widening ECDM micromilling applications lies in how to improve the machining accuracy. To improve the machining quality of the ECDM micromilling process, microgroove machining experiments were conducted in this study. Three factors affecting ECDM micromilling performance---pulse voltage, tool rotational

Zhi-Ping Zheng; Wei-Hsin Cheng; Fuang-Yuan Huang; Biing-Hwa Yan

2007-01-01

184

Modeling of material removal in mechanical type advanced machining processes: a state-of-art review  

Microsoft Academic Search

Performance of any machining process is evaluated in terms of machining rate and surface finish produced. Higher machining rate and better surface finish are desirable for better performance of any machining process. Comprehensive qualitative and quantitative analysis of the material removal mechanism and subsequently the development of analytical model(s) of material removal (MR) are necessary for a better understanding and

Neelesh K. Jain; Vijay K. Jain

2001-01-01

185

MATERIAL PROCESSING FOR SELF-ASSEMBLING MACHINE SYSTEMS  

SciTech Connect

We are developing an important aspect of a new technology based on self-reproducing machine systems. Such systems could overcome resource limitations and control the deleterious side effects of human activities on the environment. Machine systems capable of building themselves promise an increase in industrial productivity as dramatic as that of the industrial revolution. To operate successfully, such systems must procure necessary raw materials from their surroundings. Therefore, next to automation, most critical for this new technology is the ability to extract important chemicals from readily available soils. In contrast to conventional metallurgical practice, these extraction processes cannot make substantial use of rare elements. We have designed a thermodynamically viable process and experimentally demonstrated most steps that differ from common practice. To this end we had to develop a small, disposable vacuum furnace system. Our work points to a viable extraction process.

K. LACKNER; D. BUTT; C. WENDT

1999-06-01

186

Implementing a grolishing process in Zeeko IRP machines.  

PubMed

The removal of mid-spatial-frequency errors is a challenging issue in most subaperture polishing technologies. A novel "grolishing" technology has been developed to deal with grinding errors of spatial wavelengths from 1 to 50 mm with the help of power spectral density analysis and filter theory. This grolishing process was implemented on Zeeko's IRP polishing machine, on which all the subsequent polishing was performed. This has greatly reduced the process time. Although different abrasive have been used, the process is self-contained. The process parameters have been optimized to leave an edge upstand of peak-to-valley of 1 ?m over a width of 40 mm. PMID:23033036

Yu, Guoyu; Walker, David; Li, Hongyu

2012-09-20

187

Self-modulating abrasive medium and its application to abrasive flow machining for finishing micro channel surfaces  

Microsoft Academic Search

This study developed a self-modulating abrasive medium whose viscosity and fluidity can be adjusted during the processing\\u000a period. The complex micro channel was fabricated on the stainless steel (SUS304) by using wire electrical discharge machining\\u000a (wire-EDM). An experiment of employing abrasive flow machining (AFM) was conducted to evaluate the characteristics of various\\u000a levels of roughness and finishing of the micro

Hsinn-Jyh Tzeng; Biing-Hwa Yan; Rong-Tzong Hsu; Yan-Cherng Lin

2007-01-01

188

Artificial neural networks for machining processes surface roughness modeling  

Microsoft Academic Search

In recent years, several papers on machining processes have focused on the use of artificial neural networks for modeling\\u000a surface roughness. Even in such a specific niche of engineering literature, the papers differ considerably in terms of how\\u000a they define network architectures and validate results, as well as in their training algorithms, error measures, and the like.\\u000a Furthermore, a perusal

Fabricio J. Pontes; João R. Ferreira; Messias B. Silva; Anderson P. Paiva; Pedro Paulo Balestrassi

2010-01-01

189

Capacitive sensors for process control in industrial marble machines  

Microsoft Academic Search

The paper presents the design of capacitive sensors for process control in marble industry, particularly for the contact-less detection of the presence of stone samples under the abrasive\\/cutting heads in an industrial machine. Different types of sensors are proposed whose performances have been assessed through experimental test campaigns considering real working conditions. Compared to state-of-art sensors the proposed solutions (capacitive

Sergio Saponara; Fabrizio Iacopetti; Andrea Carrafiello; Elisa Valentini; Luca Fanucci; Bruno Neri

2009-01-01

190

In-process machine tool vibration cancellation using PMN actuators  

Microsoft Academic Search

At present, the machine tool technology in the US is not in the state-of-the-art of leading international competitors. Conventional machine tools under use are being pushed into their machining accuracy limits. There is a pressing need calling for revitalizing the machine tool industry. This paper presents, a mechatronic system developed for reducing tool vibration during machining. It consists of electrical

Zelalem Eshete; Guangming Zhang

1996-01-01

191

Study on Nano-machining Process Using Mechanism of a Friction Force Microscope  

Microsoft Academic Search

Nano-machining experiments are necessary in order to quantitatively understand the nano-machining process. A unique nano-machining and measurement FFM system, which has a stiff cantilever for processing, has been developed. The system can machine hard material with the removal bit size of 1-100 nm. The experimental results revealed two key characteristics of nano-machining. Firstly, the shape of the trace varies because

Kiwamu Ashida; Noboru Morita; Yoshitaro Yoshida

2001-01-01

192

Multi-small hole drilling by EDM  

NASA Astrophysics Data System (ADS)

Electrodischarge machining processes were developed so that large numbers of small cooling holes can be drilled at economic production rates in gas turbine components. Developments in electrode contact and refeed systems, multidirectional electrode guides and machine tools are described. Trends in small hole drilling technology are indicated.

Toller, D. F.

1983-04-01

193

Cylindrical Wire Electrical Discharge Machining of Metal Bond Diamond Wheels- Part II: Wheel Wear Mechanism  

SciTech Connect

The use of stereo scanning Electron Microscopy (SEM) to investigate the wear mechanism of the wire EDM true metal bond diamond wheel for ceramic grinding is presented. On the grinding wheel, a wedge-shape removal part was machined to enable the examination and measurement of the worn wheel surfaces using the stereo SEM. The stereo SEM was calibrated by comparing results of depth profile of a wear groove with the profilometer measurements. On the surface of the grinding wheel after wire EDM truing and before grinding, the diamond protruding heights were measured in the level of 35 {micro}m, comparing to the 54 {micro}m average size of the diamond in the grinding wheel. The gap between the EDM wire and rotating grinding wheel is estimated to be about 35 to 40 {micro}m. This observation indicates that, during the wire EDM, electrical sparks occur between the metal bond and EDM wire, which leaves the diamond protruding in the gap between the wire and wheel. The protruding diamond is immediately fractured at the start of the grinding process, even under a light grinding condition. After heavy grinding, the grinding wheel surface and the diamond protrusion heights are also investigated using the stereo SEM. The height of diamond protrusion was estimated in the 5 to 15 {micro}m range. This study has demonstrated the use of stereo SEM as a metrology tool to study the grinding wheel surface.

McSpadden, SB

2002-01-22

194

Reduction of Overcut in the Electrochemical Discharge Machining Process Using a Side-insulated Electrode  

Microsoft Academic Search

Electrochemical discharge machining (ECDM) process utilizes the spark discharge produced by gas film formation during electrolysis. In conventional ECDM process precise control of the spark generation is difficult because of the randomness of gas film formation which results in the significant deterioration of process qualities such as excessive overcut, poor machining accuracy and low machining repeatability. The undesirable overcut phenomenon

Min-Seop Han; Byung-Kwon Min; Sang Jo Lee

2008-01-01

195

Method and devices for automatically supplying material to a processing machine  

US Patent & Trademark Office Database

A processing machine, such as a printing press, is supplied with materials, such as rolls of paper, under the control of a control system. The control system is of a higher order than either of the material supply system and the processing machine. It is connected to both the supply system and the processing machine for transmitting data using signals.

2008-12-09

196

High resolution lithography-compatible micro-electro-discharge machining of bulk metal foils for micro-electro-mechanical systems  

NASA Astrophysics Data System (ADS)

The application of batch mode micro-electro-discharge machining (microEDM) to the fabrication of micro-electro-mechanical systems has opened the door to lithographically compatible precision machining of all bulk metals. High volume applications in biomedical, communications, and consumer electronics devices are enabled by this technology. This dissertation explores the capabilities, limitations, and further improvement of high density batch mode microEDM. There are four parts to this effort described below. A machining resolution study of high density features in stainless steel identifies the design space. Lithographically fabricated copper tools with single cross, parallel line, and circle/square array features of 5--100microm width and 5--75microm spacing were used. The observed discharge gap varies with shape, spacing, and feature location from 3.8--8microm. As tool feature density is increased, debris accumulation effects begin to dominate, eventually degrading both tool and workpiece. Two new techniques for mitigating this debris build-up are separately investigated. The first is a silicon passivation coating which suppresses spurious discharges triggered from the sidewalls of the machining tool. By this method, for high density batch machining, mean tool wear rate decreases from a typical rate of about 34% to 1.7% and machining non-uniformity reduces from 4.9microm to 1.1microm across the workpiece. The second involves a two-step machining process that enhances the hydraulic removal of machining debris and therefore throughput. Wireless RF signals are inherently emitted by the micro-discharge process. This thesis describes the first reported wireless detection of debris accumulation during microEDM, enabling direct monitoring of machining quality in real time with 5dBm signal drop. The first wireless detection of the interface between two stacked metals during microEDM is also reported giving a 10dBm signal change. The technique enables direct monitoring of the discharge without the influence of terminal parasitics. Finally, the first study of the residual stress due to the recast layer left behind by microEDM is presented. The recast layer stress-thickness product ranged from 0.5--6 GPa-microm for discharge energies from 0.03--20microJ. The recast layer thickness ranges from 0.2--3.3microm. Low energy discharges allow precision microstructures to be fabricated from bulk metals. Application of microEDM technology to RF switches and stents is in the appendices.

Richardson, Mark Thomas

197

Surface Properties in Electric Discharge Machining.  

National Technical Information Service (NTIS)

Research on electric discharge machining (EDM) parameters, workpiece surface variables, and flaw structure is summarized. Relations between crater diameter, crater depth, surface roughness, discharge current, ignition delay, discharge pulse width, dischar...

F. Roethel

1988-01-01

198

Electrical-Discharge Machining Of Perpendicular Passages  

NASA Technical Reports Server (NTRS)

Perpendicular telescoping electrode used to perform electrical-discharge machining (EDM) of internal passage through previously inaccessible depth of metal workpiece. More specifically, used to make internal passage perpendicular to passage entering from outer surface.

Malinzak, R. Michael; Booth, Gary N.

1996-01-01

199

Multi-Small Hole Drilling by Edm.  

National Technical Information Service (NTIS)

Electrodischarge machining processes were developed so that large numbers of small cooling holes can be drilled at economic production rates in gas turbine components. Developments in electrode contact and refeed systems, multidirectional electrode guides...

D. F. Toller

1983-01-01

200

3D microstructuring of Pyrex glass using the electrochemical discharge machining process  

NASA Astrophysics Data System (ADS)

Electrochemical discharge machining (ECDM) is demonstrated to be a potential process for 3D microstructuring of Pyrex glass. However, the key to widening ECDM micromilling applications lies in how to improve the machining accuracy. To improve the machining quality of the ECDM micromilling process, microgroove machining experiments were conducted in this study. Three factors affecting ECDM micromilling performance—pulse voltage, tool rotational rate and travel rate of tool—were taken up as machining parameters to investigate their influences on machining performance. The results indicate that optimum combinations of both pulse voltage and tool rotational rate will realize better machining accuracy. The feasibility of three-dimensional microstructure machining was demonstrated by layer-by-layer ECDM micromilling machining. Complex structures were made to demonstrate the great potential for the 3D microstructuring of Pyrex glass of the ECDM micromilling process.

Zheng, Zhi-Ping; Cheng, Wei-Hsin; Huang, Fuang-Yuan; Yan, Biing-Hwa

2007-05-01

201

Statistical process control (SPC) for coordinate measurement machines  

SciTech Connect

The application of process capability analysis, using designed experiments, and gage capability studies as they apply to coordinate measurement machine (CMM) uncertainty analysis and control will be demonstrated. The use of control standards in designed experiments, and the use of range charts and moving range charts to separate measurement error into it's discrete components will be discussed. The method used to monitor and analyze the components of repeatability and reproducibility will be presented with specific emphasis on how to use control charts to determine and monitor CMM performance and capability, and stay within your uncertainty assumptions.

Escher, R.N.

2000-01-04

202

Characterization of electric discharge machining, subsequent etching and shot-peening as a surface treatment for orthopedic implants  

NASA Astrophysics Data System (ADS)

Presented work aims at multi-method characterization of combined surface treatment of Ti-6Al-4V alloy for biomedical use. Surface treatment consists of consequent use of electric discharge machining (EDM), acid etching and shot peening. Surface layers are analyzed employing scanning electron microscopy and energy dispersive X-ray spectroscopy. Acid etching by strong Kroll's reagent is capable of removing surface layer of transformed material created by EDM. Acid etching also creates partly nanostructured surface and significantly contributes to the enhanced proliferation of the bone cells. The cell growth could be positively affected by the superimposed bone-inspired structure of the surface with the morphological features in macro-, micro- and nano-range. Shot peening significantly improves poor fatigue performance after EDM. Final fatigue performance is comparable to benchmark electropolished material without any adverse surface effect. The proposed three-step surface treatment is a low-cost process capable of producing material that is applicable in orthopedics.

Stráský, Josef; Havlíková, Jana; Ba?áková, Lucie; Harcuba, Petr; Mhaede, Mansour; Jane?ek, Miloš

2013-09-01

203

White Layer Composition, Heat Treatment, and Crack Formation in Electric Discharge Machining Process  

NASA Astrophysics Data System (ADS)

Characteristics of electric discharge machined (EDM) surfaces of normalized, quenched, and quenched and tempered-treated steels in kerosene and deionized-water dielectric liquids are investigated. Optical microscopy, scanning electron microscopy (SEM) and X-ray diffractometry are employed to analyze the machined surface. Surface cracks are examined in terms of white layer composition, heat treatment of the workpiece material, and operational parameters used, such as average discharge current and pulse-on duration. The present results reveal that base material properties and white layer composition have a distinctive function on crack formation that results in different crack network layouts on the surface and penetration depths in the substrate. Surface cracks, which initiate at the surface, travel down perpendicularly toward the interferential zone, and terminate at this interference, are mainly formed due to an increase in nonhomogeneities of metallurgical phases within the white layer. Such cracks are usually encountered on the surfaces when machining is performed in a hydrocarbon-based dielectric liquid using high pulse-on duration and low average discharge current. On the other hand, penetrating cracks, which penetrate the entire white layer thickness to an extent into the parent material, are mainly formed due to contraction of the recast structure joined to the circumferential edge of a crater rim during solidification. This type of crack is common when machining is performed in deionized water and the work material is brittle. Crack penetration depth is found to be proportional to the used pulse energy, and its path has a tendency to form parallel cracks to the machined surface at decreased pulse-on duration.

Ekmekci, Bülent

2009-02-01

204

Integrated quality control architecture for multistage machining processes  

NASA Astrophysics Data System (ADS)

To solve problems concerning the process quality prediction control for the multistage machining processes, a integrated quality control architecture is proposed in this paper. First, a hierarchical multiple criteria decision model is established for the key process and the weight matrix method stratified is discussed. Predictive control of the manufacturing quality is not just for on-site monitoring and control layer, control layer in the enterprise, remote monitoring level of quality exists a variety of target predictive control demand, therefore, based on XML to achieve a unified description of manufacturing quality information, and in different source of quality information between agencies to achieve the transfer and sharing. This will predict complex global quality control, analysis and diagnosis data to lay a good foundation to achieve a more practical, open and standardized manufacturing quality with higher levels of information integration system.

Yang, Jie; Liu, Guixiong

2010-12-01

205

Design and Testing of a Friction Stir Processing Machine for Laboratory Research  

SciTech Connect

This presentation describes the design, fabrication and testing of a friction stir processing machine. The machine is intended to be a flexible research tool for a broad range of friction stir processing studies. The machine design also addresses the need for an affordable, robust design for general laboratory use.

Karen S. Miller; Rodney J. Bitsoi; Eric D. Larsen; Herschel B. Smartt

2006-08-01

206

Fixed abrasive diamond wire machining—part I: process monitoring and wire tension force  

Microsoft Academic Search

The process monitoring and mechanics of fixed abrasive diamond wire saw machining are investigated in this study. New techniques to affix diamond particles to a steel wire core have advanced to make this process feasible for the machining of ceramics, wood, and foam materials. Developments in fixed abrasive diamond wire machining are first reviewed. Advantages of using fixed abrasive diamond

W. I. Clark; A. J. Shih; C. W. Hardin; R. L. Lemaster; S. B. McSpadden

2003-01-01

207

Evaluation of near-dry machining effects on gear milling process efficiency  

Microsoft Academic Search

One of the main environmental pollution sources related to machine building industry is the huge amount of cutting fluids which are supplied during the machining processes. In order to avoid the problems induced by cutting fluids' usage, considerable progress has been recently made in the field of near-dry machining (NDM). Converting conventional processes to minimal quantity lubrication (MQL) methods imposes

Domnita Fratila

2009-01-01

208

High-Speed Electrical Discharge Machining By Using a 5-DOF Controlled Maglev Local Actuator  

NASA Astrophysics Data System (ADS)

The objective of this study is to realize high-speed electrical discharge machining (EDM) using a wide-bandwidth, high-precision, millimeter-stroke, 5-DOF controlled maglev local actuator. In this paper, we report on the EDM of 1mm diameter holes using the maglev local actuator, and discuss the relationships between machining speed, the bandwidth of the actuator and the control gain of the EDM system. The experimental results show that the machining speed using the maglev local actuator was improved as the bandwidth of the actuator and control gains of the EDM system increased.

Zhang, Xiaoyou; Shinshi, Tadahiko; Shimokohbe, Akira; Sato, Tatsushi; Miyake, Hidetaka; Nakagawa, Takayuki

209

Laser cladding of copper-based materials for building electrical discharge machining electrode  

NASA Astrophysics Data System (ADS)

The paper investigates the feasibility of laser cladding of copper-based materials. As an application aspect of rapid prototyping (RP), the process could be used to build electrodes for electrical discharge machining (EDM). Two types of material system-Cu/W (with and without nickel) and Cu/B4C (with and without nickel) in certain compositions were studied. The laser cladding was conducted in a 3000W CO2 laser machine using various parameters. The microstructures of laser cladding samples were checked and analysed by SEM. The performance of electrodes made from these materials was examined in the terms of machining rate and wear rate.

Tang, Y.; Lu, Li; Fuh, Jerry Y.; Wong, Yoke-San; Gupta, M.; Zhu, H.

2002-02-01

210

Surface integrity evolution from main cut mode to finish trim cut mode in W-EDM of shape memory alloy  

NASA Astrophysics Data System (ADS)

Shape memory alloys such as Nitinol are widely used in medical, aerospace, actuator, and machine tool industries. However, Nitinol is a very difficult-to-machine material due to the superelasticity, high ductility, and severe strain-hardening. The machined surface should have tailored micro texture to enhance cell adhesion. This study explores the process capability of W-EDM (DI-water based dielectric) in machining Ni50.8Ti49.2 by one main cut (MC) mode followed by four trim cut (TC) modes. Experimental results show that the 6-sigma distributions of Ra are very different between MC mode and finish TC mode. Thick white layers (2-8 ?m) with microcracks in MC mode and very thin white layers (0-2 ?m) free of those defects in finish TC mode can be observed. However, microcracks would not propagate into the heat affected zone (HAZ) below the white layer. The microhardness of white layer by TC mode is about 50% higher than that by MC mode. In addition, Ni is the dominant element for the measured microhardness.

Liu, J. F.; Li, L.; Guo, Y. B.

2014-07-01

211

T700 Turbine Nozzle Manufacturing Technology Program. Computer Assisted EDM. Cooling Flow Measurement by IR. Automated Optical Area Measurement.  

National Technical Information Service (NTIS)

This program consisted of three separate tasks relative to the improvement of T700 turbine nozzle manufacturing process. (1) Computer Assisted EDM - This report documents a series of four experiments performed at the Manufacturing Technology Laboratory in...

G. R. Dearth T. Bantel D. Mack V. Bolduc

1981-01-01

212

Support Vector Machines for 3D Shape Processing  

Microsoft Academic Search

We propose statistical learning methods for approximating implicit surfaces and computing dense 3D deformation fields. Our approach is based on Support Vector (SV) Machines, which are state of the art in machine learning. It is straightforward to implement and computationally competitive; its parameters can be automatically set using standard machine learning methods. The surface approximation is based on a modified

Florian Steinke; Bernhard Schölkopf; Volker Blanz

2005-01-01

213

Towards an EDM Measurement in Radium-225  

NASA Astrophysics Data System (ADS)

The existence of an atomic electric dipole moment (EDM) would violate both the time and parity symmetries of nature, and so the measurement of one would give a valuable window into physics beyond the standard model. Here we describe recent progress towards measurement of the EDM of radium-225, which is expected to be abnormally large compared to other species. Neutral cold radium atoms are loaded from a magneto-optic trap into an optical dipole trap (ODT), which is mechanically translated to move the radium into the science region. We then transfer the atoms to a second, standing wave ODT suitable for the EDM measurement. In the near future, we plan to optically pump and observe nuclear spin precession. This research is supported by DOE, Office of Nuclear Physics contract No. DE-AC02-06CH11357.

Dietrich, Matthew; Bailey, K.; Greene, J.; Holt, R.; Kalita, M.; Korsch, W.; Lu, Z.-T.; Mueller, P.; O'Connor, T.; Parker, R.; Singh, J.

2012-06-01

214

[Ti-Ni shape memory alloy for dental use. Trial production of prefabricated straight-slit type posts by electric discharge machining].  

PubMed

The possibility of dental application of Ti-Ni shape memory alloys was examined. To determine whether this material which is difficult to be machined could be processed by the electric discharge machining method (E.D.M.), the E.D.M. characteristics of this material were investigated. Trial straight-slit type posts were made by this material under an appropriate electric condition. The term of yield strength, retention force after cementing, and pressure of post when into a root canal filled unset cement were investigated. Ti-Ni shape memory alloy could be processed without a loss of shape memory effect by E.D.M. Hardenning layer in the machined surface was observed by both Ram-type and Wire-type E.D.M., but a thinner hardening layer was observed by the latter method. The retention force after cementing of the trial straight-slit type post were the same or stronger than those of posts on the market. Especially, the dependence for the post's length on this strength was not strong in the trial posts. The pressure produced by inserting the trial post into the root canal filled with unset cement was very low compared with those of post on the market. The trial straight-slit type posts made of Ti-Ni shape memory alloy may be useful for dental application. PMID:2700253

Hasegawa, K

1989-05-01

215

EDM Studies on Aluminum Alloy-Silicon Carbide Composites Developed by Vortex Technique and Pressure Die Casting  

Microsoft Academic Search

Aluminum based metal matrix composites (MMCs) offer potential for advanced structural applications when high specific strength and modulus, as well as good elevated temperature resistance, are important. In the present work, aluminum alloy-silicon carbide composites were developed using a new combination of vortex method and pressure die casting technique. Electrical Discharge Machining (EDM) studies were conducted on the aluminum alloy-silicon

M. Kathiresan; T. Sornakumar

216

Bulk-Metal-Based Mems Fabricated by Micro-Electro-Discharge Machining  

Microsoft Academic Search

This paper presents the recent development of micro-electro-mechanical systems (MEMS) and devices realized by planar micromachining of metal foils. New types of cardiac stents including sensor-integrated antenna stents, a micromachined Kelvin probe with an integrated actuator, an intraluminal flow sensor cuff, and a mechanically\\/chemically robust capacitive pressure sensor are reported. Micro-electro-discharge machining (muEDM) and the modified processes were used for

Kenichi Takahata; Yogesh B. Gianchandani

2007-01-01

217

Material removal rate and electrode wear study on the EDM of silicon carbide  

Microsoft Academic Search

In this work, a material removal rate (MRR) and electrode wear (EW) study on the die-sinking electrical discharge machining (EDM) of siliconised or reaction-bonded silicon carbide (SiSiC) has been carried out. The selection of the above-mentioned conductive ceramic was made taking into account its wide range of applications in the industrial field: high-temperature gas turbines, bearings, seals and lining of

C. J. Luis; I. Puertas; G. Villa

2005-01-01

218

Current mode controlled LCC resonant converter for electrical discharge machining applications  

Microsoft Academic Search

In this paper, a contribution to the electrical discharge machining (EDM) technology is presented. The final aim of this research is to develop small size EDM systems and determine the influence of the voltage and current of the output electrical arc on the quality and efficiency of the workpiece machining. The proposed system is a DC to DC LCC resonant

Rosario Casanueva; Manuel Ochoa; Francisco J. Azcondo; S. Bracho

2000-01-01

219

A high-efficiency approach for fabricating mass micro holes by batch micro EDM  

NASA Astrophysics Data System (ADS)

This work is a follow-up study based on previous research. The study presents a novel approach for effective production of mass micro holes. Initially, a set of micro w-EDM mechanisms is designed and mounted on the developed precise tabletop CNC machine tool to fabricate the micro electrode array. The tension of the micro wire is precisely controlled by a magnetic force. Furthermore, micro vibrations of the wire during discharging are effectively suppressed by the developed vibration suppression system. To fabricate the mass micro holes, a microstructure array with a high-aspect ratio of 10 × 10 micro squared electrodes, width and height of 21 µm and 700 µm, respectively, for each electrode and 24 µm spacing between two electrodes is fabricated first by using the proposed 'reverse w-EDM' machining strategy. The electrodes array is directly utilized to drill the mass micro holes by bath micro EDM on the same machine. An array of 900 through-holes of the same size is successfully fabricated via the modified peck-drilling method on a 30 µm thick stainless-steel plate. A tip at the free end of the micro electrode is designed and fabricated as a circular-pyramid shape. Experimental results verified that the spiky end form eliminates debris adhering to the edges of the micro holes. Analytical results demonstrate satisfactory hole geometric accuracy, dimensional accuracy and surface roughness. Furthermore, mass micro holes can be fabricated efficiently using the proposed technique.

Chen, Shun-Tong

2007-10-01

220

Practical evaluation of optical-proximity effect correction by EDM methodology  

NASA Astrophysics Data System (ADS)

Practical evaluation method for optical proximity effect correction (OPC) feasibility is newly proposed using EDM (Exposure-Defocus and Mask fabrication latitude) methodology. In this method, printed image on a wafer is characterized by process latitude functions derived from EDM methodology in terms of exposure latitude, depth of focus, and mask line width latitude. In this paper, effectiveness of the process latitude functions will be verified by applying them to intraproximity effect evaluation for isolated lines and angled lines, and also to interproximity effect evaluation for T-shaped patterns and lines & spaces (L/S) patterns in i-line lithography.

Sugawara, Minoru; Kawahira, Hiroichi; Tsudaka, Keisuke; Nozawa, Satoru

1995-05-01

221

Search for permanent EDM using laser cooled Fr atoms  

NASA Astrophysics Data System (ADS)

The existence of a non-zero electric dipole moment (EDM) implies the violation of time reversal symmetry. As the time-reversal symmetry violation predicted by the Standard Model (SM) for the electron EDM is too small to be observed with current experimental techniques and any a non-zero EDM would indicate new physics beyond the SM. The tiny signal from the electron EDM is enhanced in the heavy atoms such as francium (Fr). We are constructing the laser-cooled Fr factory to search for the electron EDM.

Kawamura, Hirokazu; Aoki, T.; Arikawa, H.; Ezure, S.; Furukawa, T.; Harada, K.; Hatakeyama, A.; Hatanaka, K.; Hayamizu, T.; Imai, K.; Inoue, T.; Ishikawa, T.; Itoh, M.; Kato, T.; Murakami, T.; Nataraj, H. S.; Sato, T.; Shimizu, Y.; Wakasa, T.; Yoshida, H. P.; Sakemi, Y.

2013-03-01

222

In-process EDM truing to generate complex contours on metal-bond, superabrasive grinding wheels for precision grinding structural ceramics  

SciTech Connect

The demand and use of precision grinding of structural ceramics continue to increase as the worldwide advanced ceramic industry surpasses $20 billion is sales. Included in this industry are engineering structural ceramics, electronic ceramics, bioceramics and others. These materials are used in applications such as engine components, casting and extrusion dies, bearings, medical implants, nozzles, thermal insulators, and more. Along with the variety of ceramic applications comes a broad range of precision requirements, which in turn leads to various required processes to accommodate a spectrum of specifications. A process for grinding ceramic components to micrometer tolerances was employed and further developed at Lawrence Livermore National Laboratory for two separate grinding projects.

Piscotty, M.A.; Davis, P.J.; Saito, T.T.; Blaedel, K.L.; Griffith, L.

1997-08-01

223

Progress of the Jila Electron Edm Experiment  

NASA Astrophysics Data System (ADS)

Molecules can be advantageous for the search for the electron electric dipole moment (eEDM) due to the large effective electric field experienced by a bound, unpaired electron. Furthermore, the closely-spaced states of opposite parity make the molecules easy to polarize in the lab frame. The JILA eEDM experiment currently uses HfF^+ molecules in an ion trap to achieve long coherence times to reduce systematics. When an electric field is applied the eEDM signal is proportional to the shift in energy splitting between two Zeeman levels in a low-lying, metastable ^3?_1 state. We have previously shown efficient preparation of trapped HfF^+ molecules in the rovibronic ground state, X^1?^+(v=0,J=0). Here, we demonstrate coherent transfer of population from the ground state to the a^3?_1(v=0, J=1) state through an intermediate ^3?_{0+} state and efficient state read-out using photodissociation. In addition, we have begun to take spectroscopy data of the hyperfine and Zeeman structure of the eEDM science state in the presence of a rotating bias electric field and a magnetic field. A. E. Leanhardt et. al., Journal of Molecular Spectroscopy 270, 1-25 (2011). H. Loh et. al., Journal of Chemical Physics 135, 154308 (2011).

Loh, Huanqian; Cossel, Kevin C.; Grau, Matt; Gresh, Daniel N.; Ni, Kang-Kuen; Ye, Jun; Cornell, Eric A.

2013-06-01

224

Study on the nano-powder-mixed sinking and milling micro-EDM of WC-Co  

Microsoft Academic Search

Present study investigates the feasibility of improving surface characteristics in the micro-electric discharge machining\\u000a (EDM) of cemented tungsten carbide (WC–Co), a widely used die and mould material, using graphite nano-powder-mixed dielectric.\\u000a In this context, a comparative analysis has been carried out on the performance of powder-mixed sinking and milling micro-EDM\\u000a with view of obtaining smooth and defect-free surfaces. The surface

Muhammad Pervej Jahan; Mustafizur Rahman; Yoke San Wong

2011-01-01

225

PROCESS MONITORING OF ABRASIVE FLOW MACHINING USING A NEURAL NETWORK PREDICTIVE MODEL  

Microsoft Academic Search

This paper discusses the preliminary development of a neural network based process monitor and off-line controller for abrasive flow machining of automotive engine intake manifolds. The process is only observable indirectly, yet the time at which machining achieves the specified air flow rate must be estimated accurately. A neural network model is used to estimate when the process has achieved

Sarah S. Y. Lam; Alice E. Smith

1997-01-01

226

Modelling the abrasive flow machining process on advanced ceramic materials  

Microsoft Academic Search

Abrasive flow machining (AFM) is a unique machining method used to achieve high surface quality on inner, difficult-to-access and on outside contours. Using AFM, it is possible to realise predefined edge rounding on any brittle or hard material. AFM is easy to integrate in an automated manufacturing environment. The abrasive medium applied during AFM is a fluid consisting of a

Eckart Uhlmann; Vanja Mihotovic; Andre Coenen

2009-01-01

227

Machine vision processing\\/selection in printed circuit board manufacturing  

Microsoft Academic Search

Machine vision applications are common in the manufacturing of PWBs. Machine vision systems are used in the placement of surface mount devices with lead pitch of 0.025 inch or less. There are two steps in the successful placement of surface mount devices, as follows: (a) The location of the device on the vacuum tip which picks and places the device

A. Trivedi; Paul Cheng-Hsin Liu

1997-01-01

228

Effect of near-surface residual stress and microstructure modification from machining on the fatigue endurance of a tool steel  

NASA Astrophysics Data System (ADS)

This study concerns the effect of machining on the fatigue life of an EN X155CrMoV12 tool steel (SAE J438b), with regard to the generation of near-surface residual stress and microstructural modification of the machined surface. Two possible methods for machining tool steels were compared: electro-discharge machining (EDM), a high energy density process, and milling, a more conventional cutting process. Particular attention was given to characterization of the surface roughness, microstructure, and residual stress, using a combination of microstructural analysis, crack observation, scanning electron microscopy (SEM), x-ray diffraction (XRD), and chemical composition changes by energy-dispersive x-ray. A decrease of around 35% in the fatigue limit was observed for the EDM samples, compared with the milled samples. This was attributed to a tensile residual stress state after EDM, combined with significant phase transformation and hydrogen embrittlement. The milled surfaces showed no microstructural transformation or surface cracking and contained compressive residual stresses, all of which contributed to an improved fatigue resistance.

Ghanem, F.; Sidhom, H.; Braham, C.; Fitzpatrick, M. E.

2002-12-01

229

CRADA final report for CRADA number Y-1293-0185: Process modelling and machining operations development  

SciTech Connect

Lockheed Martin Energy Systems, Inc. and Ferro Corporation (formerly W. R. Grace, the original CRADA partner) have collaborated on an effort to develop techniques and processes for the cost-effective machining of ceramic components. The purpose of this effort was to develop a machining model, and grinding equipment machines and techniques for fabricating precision ceramic components. This project was designed to support Department of Energy (DOE) technical needs in manufacturing hard materials as well as enabling U.S. industry to maintain a position of leadership in the production of precision grinding machines and the machining of structural ceramic components.

Arnold, J.B.; Kruse, K.L.; Stone, P.K. [and others

1996-09-16

230

Hot Machining of Hardened Steels with Coated Carbide Inserts  

Microsoft Academic Search

Problem statement: The benefits of easier manufacture of hardened ste el components can be substantial in terms of reduced machining costs and lead times compared to the traditional route involving machining of the annealed state followed by heat treatment, grinding\\/EDM and manual finishing. But machinability of hard material throu gh conventional machining is hindered due to excessive wear of the

M. A. Lajis; A. K. M. N. Amin; A. N. M. Karim; H. C. D. M. Radzi; T. L. Ginta

2009-01-01

231

An investigation of tool-wear monitoring in a high-speed machining process  

Microsoft Academic Search

The monitoring of high-speed machining processes is a key issue for ensuring better use of new machine-tool capabilities. An investigation of tool-wear monitoring in a high-speed machining process on the basis of the analysis of different signals’ signatures in the time and frequency domains is presented in this paper. Sensorial information from relevant sensors (i.e., dynamometer, accelerometer and acoustic-emission (AE)

Rodolfo E. Haber; Jose E. Jiménez; C. Ronei Peres; José R. Alique

2004-01-01

232

Wire Electrochemical Discharge Machining of Al2O3 Particle Reinforced Aluminum Alloy 6061  

Microsoft Academic Search

The behavior of wire electrochemical discharge machining of Al2O3 particle-reinforced aluminum alloy 6061 was studied. The effects of machining voltage, current, pulse duration, and electrolyte concentration, on material removal rate (MRR) were evaluated in the light of the contribution of the electrical discharge machining (EDM) and electrochemical machining (ECM) actions. The relative strength of the EDM and ECM activities in

J. W. Liu; T. M. Yue; Z. N. Guo

2009-01-01

233

A Fast Inspection of Tool Electrode and Drilling Depth in EDM Drilling by Detection Line Algorithm  

PubMed Central

The purpose of this study was to develop a novel measurement method using a machine vision system. Besides using image processing techniques, the proposed system employs a detection line algorithm that detects the tool electrode length and drilling depth of a workpiece accurately and effectively. Different boundaries of areas on the tool electrode are defined: a baseline between base and normal areas, a ND-line between normal and drilling areas (accumulating carbon area), and a DD-line between drilling area and dielectric fluid droplet on the electrode tip. Accordingly, image processing techniques are employed to extract a tool electrode image, and the centroid, eigenvector, and principle axis of the tool electrode are determined. The developed detection line algorithm (DLA) is then used to detect the baseline, ND-line, and DD-line along the direction of the principle axis. Finally, the tool electrode length and drilling depth of the workpiece are estimated via detected baseline, ND-line, and DD-line. Experimental results show good accuracy and efficiency in estimation of the tool electrode length and drilling depth under different conditions. Hence, this research may provide a reference for industrial application in EDM drilling measurement.

Huang, Kuo-Yi

2008-01-01

234

Electrolysis Free Micro EDM in Water Using Electrostatic Induction Feeding Method  

NASA Astrophysics Data System (ADS)

This paper describes the machining characteristics of electrolysis-free micro EDM in water using the electrostatic induction feeding method. With the electrostatic induction feeding method, if deionized water is used for the working liquid, electrolysis can be prevented because bipolar voltage is applied to the working gap. Results of micro-holes drilling showed that the material removal rate with deionized water is higher than that with oil, and the oversize of holes machined in deionized water is smaller. Moreover, micro-holes could be drilled successfully even in a tap water with the oversize of several micrometers using this method.

Koyano, Tomohiro; Kunieda, Masanori

235

Achieving Small Structures in Thin NiTi Sheets for Medical Applications with Water Jet and Micro Machining: A Comparison  

NASA Astrophysics Data System (ADS)

NiTi shape memory alloys (SMA) are used for a variety of applications including medical implants and tools as well as actuators, making use of their unique properties. However, due to the hardness and strength, in combination with the high elasticity of the material, the machining of components can be challenging. The most common machining techniques used today are laser cutting and electrical discharge machining (EDM). In this study, we report on the machining of small structures into binary NiTi sheets, applying alternative processing methods being well-established for other metallic materials. Our results indicate that water jet machining and micro milling can be used to machine delicate structures, even in very thin NiTi sheets. Further work is required to optimize the cut quality and the machining speed in order to increase the cost-effectiveness and to make both methods more competitive.

Frotscher, M.; Kahleyss, F.; Simon, T.; Biermann, D.; Eggeler, G.

2011-07-01

236

Flotation machine and process for removing impurities from coals  

DOEpatents

The present invention is directed to a type of flotation machine that combines three separate operations in a single unit. The flotation machine is a hydraulic separator that is capable of reducing the pyrite and other mineral matter content of a coal. When the hydraulic separator is used with a flotation system, the pyrite and certain other mineral particles that may have been entrained by hydrodynamic forces associated with conventional flotation machines and/or by the attachment forces associated with the formation of microagglomerates are washed and separated from the coal. 4 figs.

Szymocha, K.; Ignasiak, B.; Pawlak, W.; Kulik, C.; Lebowitz, H.E.

1995-12-05

237

Electrical discharge machining: occupational hygienic characterization using emission-based monitoring.  

PubMed

Hazardous potential in industrial environments is normally assessed by means of immission-based sampling and analyses. This approach is not adequate, if effects of specific technical adjustments at machine tools or working processes on hygienic parameters should be assessed. This work has focused on the optimization of a manufacturing process (electrical discharge machining, EDM), with regard to risk reduction assessment. It is based on emission analyses rather than immision analyses. Several technical EDM parameters have been examined for their influence on air-based emissions. Worktools and workpieces used have a strong influence on aliphatic compounds and metals but not on volatile organic compounds (benzene, toluene, ethylene-benzene and xylene (BTEX)) and polycyclic aromatic hydrocarbons (PAHs) in air emissions. Increasing the dielectric (mineral oil) level above processing location decreases BTEX, chromium, nickel and PAH emissions. Aliphatic compounds, in contrast, increase in air emissions. EDM current used has a positive relationship with all substances analyzed in air emissions. Indicative immission concentrations, as can be expected under EDM conditions, are estimated in a predictive scenario. The results of this characterization give rise to an important conclusion in that risk assessment so far has been using incorrect parameters: total aliphatic compounds. Maximum level of chromium is reached long before limit values of aliphatic compounds are exceeded. Because of the fact that metals, like chromium, also have a higher hazardous potential, metal analysis should be introduced in future risk assessment. This experimental approach, that captures total emission of the electrical discharge machine, and is not solely based on immission values, has lead to a better understanding of the production process. This information is used to extract recommendations regarding monitoring aspects and protection measures. PMID:16781192

Evertz, Sven; Dott, Wolfgang; Eisentraeger, Adolf

2006-09-01

238

Improvement of surface integrity of electro-chemical discharge machining process using powder-mixed electrolyte  

Microsoft Academic Search

A new method has been investigated to improve the surface integrity of electro-chemical discharge machining (ECDM) process by use of conductive particles in the electrolyte. In conventional ECDM processes the generation of fine sparks with uniform energy has been most desired technique to improve the machining efficiency and the surface quality. However, precise control of the spark generations in ECDM

Min-Seop Han; Byung-Kwon Min; Sang Jo Lee

2007-01-01

239

Modeling of material removal and surface roughness in abrasive flow machining process  

Microsoft Academic Search

Abrasive flow machining process provides a high level of surface finish and close tolerances with an economically acceptable rate of surface generation for a wide range of industrial components. This paper deals with the theoretical investigations into the mechanism of abrasive flow machining (AFM) process. A finite element model is developed for the flow of media during AFM and the

Rajendra K. Jain; Vijay K. Jain; P. M. Dixit

1999-01-01

240

Development of a new lean lubrication system for near dry machining process  

Microsoft Academic Search

The minimal quantity of lubricant supply (MQL) technique has been applied to environment friendly machining processes. However, in the MQL technique, a large volume of oil mist is discharged to the environment. In this paper, a new lean lubrication system for a near dry machining process called “direct oil drop supply system (DOS)” is proposed. The performance of the DOS

T. Aoyama; Y. Kakinuma; M. Yamashita; M. Aoki

2008-01-01

241

Developing a Process Model for Abrasive Flow Machining  

Microsoft Academic Search

\\u000a Abrasive flow machining (AFM) is a unique machining method used to achieve high surface quality on inner, difficult-to-access\\u000a contours and on outside edges. Using AFM, it is possible to deburr complex shaped intersecting holes and to realize pre-defined\\u000a edge rounding on any brittle or hard material. Moreover it is easy to integrate into an automated manufacturing environment.\\u000a Reproducibility of results

E. Uhlmann; V. Mihotovic; H. Szulczynski; M. Kretzschmar

242

Electric Discharge Machining Device for Laboratories and Workshops.  

National Technical Information Service (NTIS)

A simple low power electric discharge machining (EDM) device for special uses in laboratories and workshops is presented. The device includes an RC generator, an electromechanical servo 3-axis work-tool alignment system and a closed dielectric fluid circu...

M. Lanxner A. Berko N. Ron

1976-01-01

243

Scheduling Jobs with Variable Job Processing Times on Unrelated Parallel Machines  

PubMed Central

m unrelated parallel machines scheduling problems with variable job processing times are considered, where the processing time of a job is a function of its position in a sequence, its starting time, and its resource allocation. The objective is to determine the optimal resource allocation and the optimal schedule to minimize a total cost function that dependents on the total completion (waiting) time, the total machine load, the total absolute differences in completion (waiting) times on all machines, and total resource cost. If the number of machines is a given constant number, we propose a polynomial time algorithm to solve the problem.

Zhang, Guang-Qian; Wang, Jian-Jun; Liu, Ya-Jing

2014-01-01

244

Application of neural network method to process planning in ship pipe machining  

NASA Astrophysics Data System (ADS)

Based on artificial neural network for process planning decision in ship pipe manufacturing, a novel method is established by analyzing process characteristics of the ship pipe machining. The process knowledge of pipe machining is shifted from the expression of the external rules to the description of the internal net weight value in order for the net inferring engine to decide the process route of pipe machining rapidly and rightly. Simulation shows that the method can resolve problems of process decision, and overcome the drawbacks of “matching difficulty” and “combination explosion” in traditional intelligent CAPP based on symbol reasoning.

Zhong, Yu-Guang; Qiu, Chang-Hua; Shi, Dong-Yan

2004-12-01

245

Electron EDM Search with Trapped Molecular Ions  

NASA Astrophysics Data System (ADS)

A sample of trapped molecular ions offers unique possibilities to search for a permanent electron electric dipole moment (EDM). Specifically, we plan to perform this search using the unpaired electron spins in the ^3?1 state of trapped HfF^+ molecular ions. The ions will be confined in a linear RF Paul trap, allowing for long electron spin coherence times for increased sensitivity to an electron EDM. Effective internal fields of the molecular ions should exceed 10^10 V/cm, and the molecules are easily polarized in ˜ 1V/cm electric fields due to a small ? doubling splitting in the ^3?1 state. HfF^+ molecular ions are created via laser ablation of a Hafnium target in the presence of a He + 1%SF6 supersonic expansion. The expansion cools the ions rovibrational and translational temperatures to a few Kelvin. We will report current experimental progress.

Stutz, Russell; Loh, Huanqian; Sinclair, Laura; Cornell, Eric

2008-05-01

246

Rupture failure and mechanical strength of the electrode wire used in wire EDM  

Microsoft Academic Search

In the application of wire EDM, wire rupture is very troublesome and impedes further increase of cutting speed. Instead of the spark characteristics or the temperature distribution, the rupture mechanism and the mechanical strength of the wire are the focus of this investigation. Wire rupture is a mechanical failure in essence, although the process heat has significant influence on the

Y. F. Luo

1999-01-01

247

Wire vibration, bowing, and breakage in wire electrical discharge machining  

NASA Astrophysics Data System (ADS)

This article provides an analysis of the wire electrical discharge machining (EDM) process. The causes of wire vibration, bowing, and breakage are identified. The cross sectional configuration of an eroded wire is derived from basic physics under the assumption that the erosion rate is constant. This configuration is verified experimentally with further explanation as to why numerous experimental studies have yielded different configurations. A computational model has been developed that can evaluate the systematic effects that lead to wire breakage by determining the stress induced by wire erosion and the stress induced by the sparks during the operation of a wire-cutting EDM machine. This model is also capable of determining the extent of wire bowing and vibrations in these machines but only in the frontal direction. The model is supported by data from experiments performed on an AGIECUT 612 wire machine cutting a 10 mm high copper bar with a 0.15 mm brass wire to acquire wire breakage data. The nearly parabolic shape of the bowed wire agrees with the results of other authors making more restrictive assumptions.

Arunachalam, C.; Aulia, M.; Bozkurt, B.; Eubank, P. T.

2001-04-01

248

Open system architecture modular tool kit for motion and machining process control  

Microsoft Academic Search

A user-friendly reconfigurable and modular monitoring and control system for computerized numerical control (CNC) machine tool control and machining process monitoring is described. The main part of the system is a fully integrated combination of a real-time preemptive operating system (ORTS-DSP) for machine-level soft real-time tasks running on digital signal processor (DSP) boards and an enhanced Windows-NT-based environment (ORTS-PC\\/NT), running

N. Arda Erol; Yusuf Altintas; Mabo Robert Ito

2000-01-01

249

Micro and nano electrical discharge machining in microfluidics and micro nanotechnology  

Microsoft Academic Search

Potential applications of micro and nano EDM in the research in micro nanotechnology and microfluidics are first discussed.\\u000a Milling EDM, one variation of EDM, is proposed as a flexible tool for such applications. In practice EDM milling is a process\\u000a rarely used because it is difficult to prepare thin electrode tools. Therefore the use of electrochemically etched Pt-Ir electrode\\u000a tool

A. Benilov; V. Skryshevsky; Y. Robach; M. Cabrera

2008-01-01

250

Enhanced osteoblast response to electrical discharge machining surface.  

PubMed

The purpose of this study is to investigate the surface characteristics and biocompatibility of titanium (Ti) surfaces modified by wire electrical discharge machining (EDM). EDM surface characteristics were evaluated by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), thin-film X-ray diffractometry (XRD) and contact angle measurements. MC3T3-E1 cell morphology, attachment and proliferation, as well as analysis of osteoblastic gene expressions, on machined surfaces and EDM surfaces were also evaluated. EDM surfaces exhibited high super hydrophilicity, due to high surface energy. XPS and XRD revealed that a passive oxide layer with certain developing thickness onto. EDM surfaces promoted cell attachment, but restrained proliferation. Counted cell numbers increased significantly on the machined surfaces as compared to the EDM surfaces. Real-time PCR analyses showed significantly higher relative mRNA expression levels of osteoblastic genes (ALP, osteocalcin, Runx2, Osterix) in cells cultured on the EDM surfaces as compared to cells cultured on the machined surfaces. PMID:22447066

Otsuka, Fukunaga; Kataoka, Yu; Miyazaki, Takashi

2012-01-01

251

Improved Measurement of the Electron EDM  

NASA Astrophysics Data System (ADS)

The electron is predicted to be slightly aspheric,ootnotetextI. B. Khriplovich, S. K. Lamoreaux, CP Violation Without Strangeness (Springer, New York, 1997). though no experiment has ever observed this deviation. Comparing the measured and predicted shape provides a powerful test of the standard model of particle physics. The shape is also intimately related to one of the largest outstanding questions in cosmology: why is the universe almost entirely devoid of antimatter? The electron's shape can be characterised by its electric dipole moment (EDM), de, which measures the deviation of its electric interactions from purely spherical. According to the standard model, this EDM is de 10-38 e.cm -- some eleven orders of magnitude below the current experimental limit. Most extensions to the standard model predict much larger values, potentially accessible to measurement.ootnotetextE. D. Commins, Electric dipole moments of leptons, in Advances in Atomic, Molecular, and Optical Physics, Vol. 40, B. Bederson and H.Walther (Eds.), Academic Press, New York, pp. 1-56 (1999). Hence, the search for the electron EDM is a search for physics beyond the standard model. Moreover, a non-zero breaks time-reversal symmetry which, in many models of particle physics, is equivalent to breaking the symmetry between matter and antimatter, known as CP symmetry. New CP-breaking physics is thought to be needed to explain the existence of a material universe.ootnotetextA. D. Sakharov, Violation of CP invariance, C asymmetry, and baryon asymmetry of the universe, Pis'ma ZhETF 5, 32 (1967). *Sov. Phys. JETP Lett. 5, 24 (1967).] We have used cold, polar molecules to measure the electron EDM, obtaining the result de= (-2.4 ±5.7stat±1.5syst) x10-28 e.cm. We set a new upper limit of with 90% confidence. Our result, consistent with zero, indicates that the electron is spherical at this improved level of precision. Our measurement, of atto-eV energy shifts in a molecule, probes new physics at the tera-eV energy scale. Many extensions to the standard model, such as the minimal supersymmetric standard model, naturally predict large EDMs and our measurement places significant constraints on the parameters of these theories.ootnotetextE. D. Commins and D. DeMille, ``The electric dipole moment of the electron,'' Chapter 14 in Lepton Dipole Moments Eds. B. L. Roberts and W. J. Marciano, (World Scientific, Singapore 2010).

Hinds, E. A.

2011-06-01

252

A novel electrical power supply for electrothermal and electrochemical removal machining methods  

Microsoft Academic Search

For electrically conductive materials Electrical Discharge Machining (EDM), electrochemical machining (ECM) and Electrochemical Discharge Machining (ECDM) constitute a procedure to manipulate materials that are difficult to machine using conventional machining methods. Due to their different electrical behavior all three methods would usually require dedicated power supplies. This paper introduces and analyzes a novel low-loss power supply which can be used

David Tastekin; Harry Krötz; Clemens Gerlach; Jörg Roth-Stielow

2009-01-01

253

Search for electron EDM with laser cooled radioactive atom  

NASA Astrophysics Data System (ADS)

The permanent electric dipole moment (EDM) of the elementary particle has the sensitivity to the CP violation in the theories beyond the standard model (SM). The search for the EDM constitutes the stringent test to discriminate between the SM and beyond it. We plan to perform the electron EDM search by using the laser cooled francium (Fr) atom which has the largest enhancement factor of the electron EDM in the alkali atoms. In this paper, the present status of the laser cooled Fr factory that is being constructed at Cyclotron and Radioisotope Center (CYRIC), Tohoku University are reported.

Inoue, T.; Arikawa, H.; Ezure, S.; Harada, K.; Hayamizu, T.; Ishikawa, T.; Itoh, M.; Kato, T.; Kawamura, H.; Nataraj, H. S.; Sato, T.; Aoki, T.; Furukawa, T.; Hatakeyama, A.; Hatanaka, K.; Imai, K.; Murakami, T.; Shimizu, Y.; Wakasa, T.; Yoshida, H. P.; Sakemi, Y.

2013-05-01

254

Analysis and prediction of dimensions and cost of laser micro-machining internal channel fabrication process  

NASA Astrophysics Data System (ADS)

This paper presents the utilisation of Response Surface Methodology (RSM) as the prediction tool for the laser micro-machining process. Laser internal microchannels machined using pulsed Nd:YVO4 laser in polycarbonate were investigated. The experiments were carried out according to 33 factorial Design of Experiment (DoE). In this work the three input process set as control parameters were laser power, P; pulse repetition frequency, PRF; and sample translation speed, U. Measured responses were the channel width and the micro-machining operating cost per metre of produced microchannels. The responses were sufficiently predicted within the set micro-machining parameters limits. Two factorial interaction (2FI) and quadratic polynomial regression equations for both responses were constructed. It is proposed that the developed prediction equations can be used to find locally optimal micro-machining process parameters under experimental and operational conditions.

Shadi, K.; Brabazon, D.

2010-06-01

255

In-process optical metrology for precision machining  

SciTech Connect

This book contains papers divided among the following sections: Optical technology in the Netherlands; Shape and microfinish as a function of machine performance and stiffness; Repsonse of material to ideal micromachining and diamond tools; Micromachined components in optical systems, scanning interferometry; Contactless microtopography and profilometry; and Automated interferometric validation scatterometry, ellipsometry.

Langenbeck, P.

1987-01-01

256

CryoEDM: A cryogenic experiment to measure the neutron electric dipole moment  

NASA Astrophysics Data System (ADS)

CryoEDM is an experiment that aims to measure the electric dipole moment (EDM) of the neutron to a precision of 10 -28 e cm. A description of CryoEDM, the apparatus, technologies and commissioning is presented.

van der Grinten, M. G. D.; CryoEDM Collaboration; Balashov, S. N.; Francis, V.; Green, K.; Iaydjiev, P. S.; Ivanov, S. N.; Khazov, A.; Tucker, M. A. H.; Wark, D. L.; Davidson, A.; Hardiman, M.; Harris, P. G.; Katsika, K.; Pendlebury, J. M.; Peeters, S. J. M.; Shiers, D. B.; Smith, P.; Townsley, C.; Wardell, I.; Clarke, C.; Henry, S.; Kraus, H.; McCann, M.; Geltenbort, P.; Yoshiki, Y.

2009-12-01

257

Modeling gas film formation in electrochemical discharge machining processes using a side-insulated electrode  

Microsoft Academic Search

Electrochemical discharge machining (ECDM) is an effective spark-based machining method for nonconductive materials such as glass. The spark generation in ECDM processes is closely related to the electrode effects phenomenon, which has been explained as an immediate breakdown of electrolysis due to the gas film formation at the electrode surface. The initiation of the electrode effects is mainly influenced by

Min-Seop Han; Byung-Kwon Min; Sang Jo Lee

2008-01-01

258

Machine Learning for Second Language Learning: Effects on Syntactic Processing in Garden-Path Sentences  

Microsoft Academic Search

With the rapid development of educational technologies, machine learning (ML) based second language learning (SLL) attracts the attention of many scholars from computational linguistics. Garden path (GP) sentence is a special sentence structure in which processing breakdown and backtracking are involved in the machine decoding. Faced with GP sentence, learners have to make original misinterpretation linger even after reanalysis has

Du Jia-li; Yu Ping-fang

2010-01-01

259

Three-dimensional temperature predictions in machining processes using finite difference method  

Microsoft Academic Search

The purpose of this study is to determine the three-dimensional temperature fields on the chip, tool and workpiece during machining, which is one of the most important characteristic of machining processes; since the fields can affect other properties such as residual stresses and tool wear, and thus tool life and fatigue life of finished parts. The finite difference method (FDM)-based

D. Ulutan; I. Lazoglu; C. Dinc

2009-01-01

260

Implementation and evaluation of a list-processing-oriented data flow machine  

Microsoft Academic Search

The architecture of a data flow machine, called DFM, is developed for parallel list processing. The DFM can maximally exploit parallelism inherent in list processing, due to its ultra-multi-processing mechanism, packet communication-based parallel and pipeline execution mechanism, and lenient cons mechanism. A practical DFM implementation is described. A DFM prototype machine is implemented and DFM performance is evaluated in a

Makoto Amamiya; Masaru Takesue; Ryuzo Hasegawa; Hirohide Mikami

1986-01-01

261

Experimental Studies on Mechanism of Material Removal in Abrasive Flow Machining Process  

Microsoft Academic Search

In this article, the mechanism of material removal (MR) in Abrasive Flow Machining (AFM) process has been studied. Representative components of pure Aluminum and Brass were processed by AFM under similar process conditions. The processed surfaces were analyzed with the help of Scanning Electron Microscopy (SEM). SEM photographs reveal noticeable difference between abrasion patterns produced on the processed surfaces of

Sehijpal Singh; H. S. Shan; Pradeep Kumar

2008-01-01

262

Materials processing and machine applications of bulk HTS  

Microsoft Academic Search

We report a refrigeration system for rotating machines associated with the enhancement of the trapped magnetic flux of bulk high-temperature superconductor (HTS) field poles. A novel cryogenic system was designed and fabricated. It is composed of a low-loss rotary joint connecting the rotor and a closed-cycle thermosiphon under a GM cryocooler using a refrigerant. Condensed neon gas was adopted as

M. Miki; B. Felder; K. Tsuzuki; Y. Xu; Z. Deng; M. Izumi; H. Hayakawa; M. Morita; H. Teshima

2010-01-01

263

Surface Integrity of Hard Metal Parts Machined by WEDM  

NASA Astrophysics Data System (ADS)

Hard metal is characterised by having a extremely high hardness and high wear resistance, and those characteristics make difficult conventional machining. Electrical Discharge Machining (EDM) has become an attractive and feasible method for the manufacturing of precision hard metal tooling, and it is now an alternative to classical diamond grinding. This is due to the thermal nature of material removal mechanism in EDM, which is therefore independent on part hardness. This work pays attention to the analysis of surface integrity in wire EDM'ed hard metal parts. Damages on the machined surfaces have been characterised for different cutting regimes. Special attention has been paid to the heat affected zone, since it is in this zone where cracking mostly occurs. The study includes the analysis of the chemical composition of the affected layers. Additionally, the influence of successive trim cuts on surface roughness is addressed.

Plaza, S.; Izquierdo, B.; Sanchez, J. A.; Ortega, N.; Ramos, J. M.

2009-11-01

264

Direct selective laser sintering of high performance metals: Machine design, process development and process control  

NASA Astrophysics Data System (ADS)

This dissertation describes the development of an advanced manufacturing technology known as Direct Selective Laser Sintering (Direct SLS). Direct SLS is a laser based rapid manufacturing technology that enables production of functional, fully dense, metal and cermet components via the direct, layerwise consolidation of constituent powders. Specifically, this dissertation focuses on a new, hybrid net shape manufacturing technique known as Selective Laser Sintering/Hot Isostatic Pressing (SLS/HIP). The objective of research presented in this dissertation was to establish the fundamental machine technology and processing science to enable direct SLS fabrication of metal components composed of high performance, high temperature metals and alloys. Several processing requirements differentiate direct SLS of metals from SLS of polymers or polymer coated powders. Perhaps the most important distinguishing characteristic is the regime of high temperatures involved in direct SLS of metals. Biasing the temperature of the feedstock powder via radiant preheat prior to and during SLS processing was shown to be beneficial. Preheating the powder significantly influenced the flow and wetting characteristics of the melt. During this work, it was conclusively established that powder cleanliness is of paramount importance for successful layerwise consolidation of metal powders by direct SLS. Sequential trials were conducted to establish optimal bake-out and degas cycles under high vacuum. These cycles agreed well with established practices in the powder metallurgy industry. A study of some of the important transport mechanisms in direct SLS of metals was undertaken to obtain a fundamental understanding of the underlying process physics. This study not only provides an explanation of phenomena observed during SLS processing of a variety of metallic materials but also helps in developing selection schemes for those materials that are most amenable to direct SLS processing. The development of machine, processing and control technologies during this research effort enabled successful production of a number of integrally canned test specimens in Alloy 625 (InconelRTM 625 superalloy) and Ti-6Al-4V alloy. The overall goal of this research was to develop direct SLS of metals armed with a fundamental understanding of the underlying physics. The knowledge gained from experimental and analytical work is essential for three key objectives: machine design, process development and process control. (Abstract shortened by UMI.)

Das, Suman

1998-11-01

265

Studies on the fabrication of metallic bipolar plates—Using micro electrical discharge machining milling  

Microsoft Academic Search

Owed to the advantages of highly precise and flexible machining, micro electrical discharge machining milling (micro EDM milling) can machine higher aspect ratio micro flow channels than the micro flow channels made from etching or deposition techniques, which have aspect ratio of only 0.5–0.7.This study reports on the production of micro flow channels in metallic bipolar plates, using micro EDM

Jung-Chung Hung; Tzu-Chun Yang; Kuo-chou Li

266

Trapping Yb Atoms for an EDM Experiment  

NASA Astrophysics Data System (ADS)

We are investigating the possible use of a magneto-optical trap (MOT) and optical dipole trap to search for the CP-violating permanent electric dipole moment (EDM) by nuclear spin resonance in Yb (ytterbium) atoms. Optical cooling and trapping of Yb offers many advantages for an atomic EDM experiment including long spin-relaxation lifetimes and a zero average motional magnetic field v×E. The ultra-high vacuum necessary for the trap suppresses spurious magnetic fields due to leakage currents and will allow us to apply a high electric field. Similar EDM experiments have been proposed for the trapped heavy atoms Cs and Fr. However, the ^171Yb atoms are free from the large cross-sections for cold atom collisions that limit the sensitivity of the Cs and Fr experiments because Yb is diamagnetic with a spin-1/2 nucleus. We will use the ^1S0 arrow ^1P1 (398.9 nm) transition for cooling and trapping. The ^1P1 state has a relatively short lifetime of 5 ns, allowing a large laser cooling force to be applied to the atoms. The transition is almost a closed 2-state system, minimizing the need for an extra cleanup laser. We have frequency doubled a Ti:Sapphire laser with an LBO crystal to 398.9 nm and have observed fluorescence from this transition in a Yb beam. We have completed the initial studies for building the MOT and will discuss further progress and possible future experiments. Further information can be found at ?rb"http://www.phys.washington.edu/r~einam/".

Maruyama, Reina; Fortson, Norval; Romalis, Michael

1998-05-01

267

Neuro-fuzzy and neural network-based prediction of various responses in electrical discharge machining of AISI D2 steel  

Microsoft Academic Search

In the present research, two neuro-fuzzy models and a neural network model are presented for predictions of material removal\\u000a rate (MRR), tool wear rate (TWR), and radial overcut (G) in die sinking electrical discharge machining (EDM) process for American Iron and Steel Institute D2 tool steel with copper\\u000a electrode. The discharge current (I\\u000a p), pulse duration (T\\u000a on), duty cycle

Mohan Kumar Pradhan; Chandan Kumar Biswas

2010-01-01

268

Study on Nano EDM Using Capacity Coupled Pulse Generator  

Microsoft Academic Search

This paper describes the development of a pulse generator for nano EDM using a capacity coupling method. To obtain discharge craters of nanometer diameter, a pulse generator was coupled to the tool electrode by a capacitor. Since the influence of the stray capacitance in the electric feeders can be eliminated, the discharge energy can be minimized to accomplish nano EDM.

M. Kunieda; A. Hayasaka; X. D. Yang; S. Sano; I. Araie

2007-01-01

269

Investigation of complex rapid EDM electrodes for rapid tooling applications  

Microsoft Academic Search

This paper describes a collaborative research programme aimed at investigating the use of quick EDM electrodes obtained via appropriate rapid prototyping techniques in finishing laser-sintered tools. Two methods were employed in obtaining the EDM electrodes: copper coating of stereolithography models and copper coating of direct metal laser sintered (bronze) models. The amount of copper deposited on both electrode models proved

D. E. Dimla; N. Hopkinson; H. Rothe

2004-01-01

270

Analysis and prediction of dimensions and cost of laser micro-machining internal channel fabrication process  

Microsoft Academic Search

This paper presents the utilisation of Response Surface Methodology (RSM) as the prediction tool for the laser micro-machining process. Laser internal microchannels machined using pulsed Nd:YVO4 laser in polycarbonate were investigated. The experiments were carried out according to 33 factorial Design of Experiment (DoE). In this work the three input process set as control parameters were laser power, P; pulse

K. Shadi; D. Brabazon

2010-01-01

271

Geometry and surface damage in micro electrical discharge machining of micro-holes  

NASA Astrophysics Data System (ADS)

Geometry and subsurface damage of blind micro-holes produced by micro electrical discharge machining (micro-EDM) is investigated experimentally to explore the relational dependence with respect to pulse energy. For this purpose, micro-holes are machined with various pulse energies on plastic mold steel samples using a tungsten carbide tool electrode and a hydrocarbon-based dielectric liquid. Variations in the micro-hole geometry, micro-hole depth and over-cut in micro-hole diameter are measured. Then, unconventional etching agents are applied on the cross sections to examine micro structural alterations within the substrate. It is observed that the heat-damaged segment is composed of three distinctive layers, which have relatively high thicknesses and vary noticeably with respect to the drilling depth. Crack formation is identified on some sections of the micro-holes even by utilizing low pulse energies during machining. It is concluded that the cracking mechanism is different from cracks encountered on the surfaces when machining is performed by using the conventional EDM process. Moreover, an electrically conductive bridge between work material and debris particles is possible at the end tip during machining which leads to electric discharges between the piled segments of debris particles and the tool electrode during discharging.

Ekmekci, Bülent; Sayar, Atakan; Tecelli Öpöz, Tahsin; Erden, Abdulkadir

2009-10-01

272

Integration of process planning, monitoring, and control in a machine tool environment  

Microsoft Academic Search

The authors describe the integration of process planning and remote monitoring within an existing open architecture CNC. The process planning system described is designed to allow dynamic replanning of the process as well as the updating of technological information concerning tools and workpiece. The monitoring system is designed to drive a virtual machine tool at a remote location. Bibtex entry

Ian Yellowley; Rudolph J. Seethaler; F. W. Yeung

1999-01-01

273

An Investigation of Machining Characteristics in Micro-scale Milling Process  

NASA Astrophysics Data System (ADS)

In this paper, an analytical solution of micro-scale milling process is presented in order to suggest available machining conditions. The size effect should be considered to determine cutting characteristics in micro-scale cutting. The feed per tooth is the most dominant cutting parameter related to the size effect in micro-scale milling process. In order to determine the feed per tooth at which chips can be formed, the finite element method is used. The finite element method is employed by utilizing the Johnson-Cook (JC) model as a constitutive model of work material flow stress. Machining experiments are performed to validate the simulation results by using a micro-machining stage. The validation is conducted by observing cutting force signals from a cutting tool and the conditions of the machined surface of the workpiece.

Ku, Min-Su; Kang, Ik-Soo; Kim, Jeong-Suk

2011-01-01

274

An Adaptive Control of Ultraprecision Machining with an In-Process Micro-Sensor  

NASA Astrophysics Data System (ADS)

This paper presents an in-process status monitoring method for ultraprecision machining system and an adaptive control system equipped with the function. The crux of this method is an effective in-process micro sensor which can detect physical behavior around the cutting point during ultraprecision machining process. In this study, we develop a micro-miniaturized platinum resistance thermometry-type sensor with micro-fabrication process and then mount it on the rake surface of a single diamond tool tip nearby the cutting point. Through a series of cutting experiments with an ultraprecision diamond turning machine, we evaluate the developed sensor. As a result, experimental results confirm that the developed sensor has useful characteristics such as high sensitivity, compactness and quick response. In addition, we realize an adaptive control system for ulatraprecision machining process. The developed system maintains a constant temperature around the cutting point by controlling the cutting speed. Adaptive control experiment results confirm the developed system has high potential for detecting small thermal and small dynamic behavior of the cutting point during ultraprecision machining process.

Hayashi, Mamoru; Yoshioka, Hayato; Shinno, Hidenori

275

Integrated machine learning approaches for complementing statistical process control procedures  

Microsoft Academic Search

Although statistical process control (SPC) procedures have played a central role in solving quality problems, their effectiveness is yet to be fully realized in the process industry with large volume data, a lot of dimensions of variables, and complex relationships among processes and variables. To complement SPC procedures, we suggest three integrated methods of inductive learning and neural networks for

Boo-sik Kang; Sang-chan Park

2000-01-01

276

Associating a Design Model and its Machining Process Plan  

Microsoft Academic Search

One of the major problems with the conventional process of creating products is the poor association between product design and manufacturing engineering. Although, a product is represented as a 3D CAD model, in-process models (IPMs) of a process plan are usually 2D drawings that have little association with the product model. The lack of association requires an excessive amount of

Sang C. Park

2005-01-01

277

Parameter estimation for abrasive water jet machining process using neural networks  

Microsoft Academic Search

The abrasive water jet machining process, a material removal process, uses a high velocity jet of water and an abrasive particle\\u000a mixture. The estimation of appropriate values of the process parameters is an essential step toward an effective process performance.\\u000a This has led to the development of numerous mathematical and empirical models. However, the complexity of the process confines\\u000a the

Pratik J. Parikh; Sarah S. Lam

2009-01-01

278

Progress toward an EDM measurement in 225Ra  

NASA Astrophysics Data System (ADS)

Permanent electric dipole moments (EDMs) in atoms or molecules are a signature of time-reversal and parity violation and represent an important window onto physics beyond the Standard Model. We are developing a next generation EDM search based on laser-cooled and trapped 225Ra atoms. Due to octupole deformation of the nucleus, 225Ra is predicted to be two to three orders of magnitude more sensitive to T-violating interactions than 199Hg, which currently sets the most stringent limits in the nuclear sector. We will discuss progress toward realizing a first EDM measurement for 225Ra.

Holt, R. J.; Ahmad, I.; Bailey, K.; Graner, B.; Greene, J. P.; Korsch, W.; Lu, Z.-T.; Mueller, P.; O'Connor, T. P.; Sulai, I. A.; Trimble, W. L.

2010-11-01

279

Post-cast EDM method for reducing the thickness of a turbine nozzle wall  

DOEpatents

A post-cast EDM process is used to remove material from the interior surface of a nozzle vane cavity of a turbine. A thin electrode is passed through the cavity between opposite ends of the nozzle vane and displaced along the interior nozzle wall to remove the material along a predetermined path, thus reducing the thickness of the wall between the cavity and the external surface of the nozzle. In another form, an EDM process employing a profile as an electrode is disposed in the cavity and advanced against the wall to remove material from the wall until the final wall thickness is achieved, with the interior wall surface being complementary to the profile surface.

Jones, Raymond Joseph (Duanesburg, NY); Bojappa, Parvangada Ganapathy (Schenectady, NY); Kirkpatrick, Francis Lawrence (Galway, NY); Schotsch, Margaret Jones (Clifton Park, NY); Rajan, Rajiv (Guilderland, NY); Wei, Bin (Mechanicville, NY)

2002-01-01

280

Mechanism of material removal in the magnetic abrasive process and the accuracy of machining  

Microsoft Academic Search

In this paper, we focus on the magnetic abrasive process as a sizing process and present a theory which explains the out-of-roundness error phenomenon based on force analysis of the material removal mechanism. The theory is independent of the size and material of the workpiece and the design of the magnetic abrasive machine tool. The theory results are verified experimentally.

G. Z. KREMEN; E. A. ELSAYED; V. I. RAFALOVICH

1996-01-01

281

Cascade-Correlation Neural Network Modeling of the Abrasive Flow Machining Process  

Microsoft Academic Search

This paper presents some preliminary work for modeling the abrasive flow machining (AFM) of automotive engine air intake manifolds using a cascade-correlation neural network approach. AFM has not been widely used because of the lack of theoretic support for the complex behavior of the process. Currently, this process can only be monitored subjectively by the plant engineers and is not

Sarah S. Y. Lam; Alice E. Smith

282

Toward intelligent machining: hierarchical fuzzy control for the end milling process  

Microsoft Academic Search

The difficulties in implementing adaptive and other advanced control schemes in industrial machining processes have encouraged researchers to combine the utilization of one hierarchical level, a fuzzy control algorithm, and robust sensing systems. The main idea of this paper deals with self-regulating controllers (SRCs). The control signal's scaling factor (output scaling factor) is self-regulated during the control process, and it

R. E. Haber; C. R. Peres; A. Alique; S. Ros; C. Gonzalez; J. R. Alique

1998-01-01

283

Sequential monitoring of surface spatial variation in automotive machining processes based on high definition metrology  

Microsoft Academic Search

The ability to monitor machining processes within micron level is critical to high precision manufacturing. New non-contact measurement technology, such as holography based high definition metrology (HDM), makes this feasible through monitoring of both the part shape and its surface texture. However, conventional statistical process monitoring and diagnostic schemes based on low definition measurement technology have limitations in addressing the

Saumuy Suriano; Hui Wang; S. Jack Hu

284

Electrical-Discharge Machining of Multifacet Electrodes with a Single Clamp Operation.  

National Technical Information Service (NTIS)

EDM die sinking often requires the use of multifacet electrodes. Previously the electrodes were produced on ordinary milling machines, but high-precision-applications require greater precision than this technique can yield. To fill this gap, Mitsubishi El...

Y. Mishima S. Furukawa Y. Nakayama

1987-01-01

285

Rapid tooling of EDM electrodes by means of selective laser sintering  

Microsoft Academic Search

Besides using the selective laser sintering of metal powder for tooling of, e.g., moulding dies, the sintering of EDM-electrodes is one modern development in the field of the Rapid Tooling. The electrodes are built up layer by layer using the 3-D CAD data. So far, a bronze–nickel powder mixture has been used. The made optimization of the sintering process parameters

Holger Dürr; Rolf Pilz; Nuri Saad Eleser

1999-01-01

286

Laser 3D Machining with Variable Process Parameters  

NASA Astrophysics Data System (ADS)

An experimental study is presented to investigate the effects of laser cutting conditions on kerf geometry with variable process parameters. Laser traverse speed, laser power and laser focal position related to the specimen quality are varied during the cutting process to simulate the situations encountered in practice. Various trends of the kerf geometrical features in terms of the varying process parameters are presented and analyzed, and shown to be reasonable. Discussions are also given on kerf geometry control in situations where variable cutting parameters are used.

Wang, Xuyue; Wang, J.

2011-01-01

287

Micromanufacturing Of Hard To Machine Materials By Physical And Chemical Ablation Processes  

NASA Astrophysics Data System (ADS)

Miniaturization leads to high requirements to the applied manufacturing processes especially in respect to the used hard to machine materials and the aims of structure size and geometrical accuracy. Traditional manufacturing processes reach their limits here. One alternative for these provide thermal and chemical ablation processes. These processes are applied for the production of different microstructures in different materials like hardened steel, carbides and ceramics especially for medical engineering and tribological applications.

Schubert, A.; Edelmann, J.; Gross, S.; Zeidler, H.; Meichsner, G.; Hackert, M.; Wolf, N.; Schneider, J.

2011-01-01

288

New results from the YbF EDM experiment  

NASA Astrophysics Data System (ADS)

The standard model of particle physics predicts that, due to time reversal symmetry, the permanent electric dipole moment (EDM) of the electron is very nearly zero. Many extensions to the standard model predict an electron EDM or other T-violating effects just below current experimental limits, thus there is great interest in new experiments and in improving current experimental precision. I will discuss our recent measurement of the electron EDM using YbF molecules. YbF is particularly sensitive to the electron EDM. This experiment uses a form of laser-radiofrequency double resonance spectroscopy to search for very small energy differences between hyperfine levels in a strong electric field. In addition to describing the experimental and analysis techniques, I will give an overview of the techniques we use to check for systematic errors. I will also describe planned improvements to the experiment which promise several orders of magnitude improvement in sensitivity.

Sauer, B. E.

2013-04-01

289

Micromechanical Machining Processes and their Application to Aerospace Structures, Devices and Systems  

NASA Technical Reports Server (NTRS)

Micromechanical machining processes are those micro fabrication techniques which directly remove work piece material by either a physical cutting tool or an energy process. These processes are direct and therefore they can help reduce the cost and time for prototype development of micro mechanical components and systems. This is especially true for aerospace applications where size and weight are critical, and reliability and the operating environment are an integral part of the design and development process. The micromechanical machining processes are rapidly being recognized as a complementary set of tools to traditional lithographic processes (such as LIGA) for the fabrication of micromechanical components. Worldwide efforts in the U.S., Germany, and Japan are leading to results which sometimes rival lithography at a fraction of the time and cost. Efforts to develop processes and systems specific to aerospace applications are well underway.

Friedrich, Craig R.; Warrington, Robert O.

1995-01-01

290

Single machine scheduling with step-deteriorating processing times  

Microsoft Academic Search

We study in this paper a scheduling model in which each task has a normal processing time which deteriorates as a step function if its starting time is beyond a given deteriorating date. We focus on problems with identical task deteriorating dates. We show that the flow time problem is NP-complete and suggest a pseudo-polynomial algorithm for the makespan problem.

T. C. E. Cheng; Qing DING

2001-01-01

291

Microstructure, Morphology, and Nanomechanical Properties Near Fine Holes Produced by Electro-Discharge Machining  

SciTech Connect

Fine holes in metal alloys are employed for many important technological purposes, including cooling and the precise atomization of liquids. For example, they play an important role in the metering and delivery of fuel to the combustion chambers in energy-efficient, low-emissions diesel engines. Electro-discharge machining (EDM) is one process employed to produce such holes. Since the hole shape and bore morphology can affect fluid flow, and holes also represent structural discontinuities in the tips of the spray nozzles, it is important to understand the microstructures adjacent to these holes, the features of the hole walls, and the nanomechanical properties of the material that was in some manner altered by the EDM hole-making process. Several techniques were used to characterize the structure and properties of spray-holes in a commercial injector nozzle. These include scanning electron microscopy, cross-sectioning and metallographic etching, bore surface roughness measurements by optical interferometry, scanning electron microscopy, and transmission electron microscopy of recast EDM layers extracted with the help of a focused ion beam.

Blau, Peter Julian [ORNL; Howe, Jane Y [ORNL; Coffey, Dorothy W [ORNL; Trejo, Rosa M [ORNL; Kenik, Edward A [ORNL; Jolly, Brian C [ORNL; Yang, Nan [Caterpillar Inc.

2012-01-01

292

Microstructure, Morphology, and Nanomechanical Properties Near Fine Holes Produced by Electro-Discharge Machining  

NASA Astrophysics Data System (ADS)

Fine holes in metal alloys are employed for many important technological purposes, including cooling and the precise atomization of liquids. For example, they play an important role in the metering and delivery of fuel to the combustion chambers in energy-efficient, low-emission diesel engines. Electro-discharge machining (EDM) is one process employed to produce such holes. Since the hole shape and bore morphology can affect fluid flow, and holes also represent structural discontinuities in the tips of the spray nozzles, it is important to understand the microstructures adjacent to these holes, the features of the hole walls, and the nanomechanical properties of the material that was in some manner altered by the EDM hole-making process. Several techniques were used to characterize the structure and properties of spray-holes in a commercial injector nozzle. These include scanning electron microscopy, cross sectioning and metallographic etching, bore surface roughness measurements by optical interferometry, scanning electron microscopy, and transmission electron microscopy of recast EDM layers extracted with the help of a focused ion beam.

Blau, P. J.; Howe, J. Y.; Coffey, D. W.; Trejo, R. M.; Kenik, E. D.; Jolly, B. C.; Yang, N.

2012-08-01

293

Progress towards an atomic EDM measurement of Ra-225  

NASA Astrophysics Data System (ADS)

We are searching for the permanent electric dipole moment (EDM) of the Radium-225 nucleus. A nonzero nuclear EDM is a signature of CP- and T-violating interactions within nuclei. Currently, the best experimental limits on these interactions are derived from EDM measurements of Mercury-199. The Ra-225 radioisotope (half-life of 15 days) is an attractive alternative because, due to its peculiar shape (nuclear octupole deformation), it is predicted to be a few hundred to a few thousand times more sensitive to these types of interactions than Hg-199. In our measurement scheme, Ra atoms are first laser cooled and trapped in a magneto-optical trap and then transferred to an optical dipole trap (ODT), both of which have already been demonstrated. The ODT is moved to a magnetically-shielded science chamber, and then the atoms are transferred to a perpendicular ODT in which the EDM will be measured. Transfer efficiencies between the two ODT's as high as 60% have been demonstrated. We will report on progress towards measurements of atomic properties necessary for the EDM search and the EDM search itself. Research supported by DOE, Office of Nuclear Physics, contract No. DE-AC02-06CH11357.

Parker, Richard; Bailey, Kevin; Dietrich, Matthew; Greene, John; Holt, Roy; Kalita, Mukut; Korsch, Wolfgang; Lu, Zheng-Tian; Mueller, Peter; O'Conner, Tom; Singh, Jaideep

2012-03-01

294

Fiber optic diagnostic techniques applied to electrical discharge machining sparks  

NASA Astrophysics Data System (ADS)

Plasma sparks from an electrical discharge machining (EDM) process were observed using fiber optics positioned in the dielectric oil. Measurement techniques were developed to observe the spark in the extremely noisy environment. Optical data were used along with current pulse wave forms from the EDM machine to study the temporal characteristics of the spark in both the pulse time and the pause time. During the pause time, extinction of the sparks was longer than previously thought-perhaps due to the remaining infrared radiation after the collapse of the spark. Further, an optical pattern was identified that indicated in advance when an arc was being formed instead of a spark. Spectral data of the plasma spark was obtained by using a scanning grating spectrometer in conjunction with crosscorrelation to maximize the signal-to-noise ratio. Average spark temperatures from the spectral data were found to be significantly higher than those previously predicted from energy balances. The results showed a shift in the optical spectra to longer wavelengths during the spark, showing that the spark temperature decreased with time.

Pillans, B. W.; Evensen, M. H.; Taylor, H. F.; Eubank, P. T.; Ma, Lianxi

2002-02-01

295

Three-dimensional silicon microcomponents manufactured by microelectrodischarge machining  

NASA Astrophysics Data System (ADS)

Currently, nearly all microcomponents are fabricated by microelectronic production technologies like etching, deposition and other (photo)lithographic techniques. In this way, main emphasis has been put on surface micromechanics. The major challenges for the future will be the development of real 3D microstructures. Electro-discharge machining (EDM) is a so-called non-conventional machining technique, whereby material is removed through the erosive action of electrical discharges provided by a generator. As shown in this paper, electro-discharge machining proves to be a versatile technique which is very well suited for machining complex microstructures. First, an overview of the applicability of micro electro-discharge machining for manufacturing silicon micromechanical parts is given. Also the machine on which these structures were made is introduced. The main advantages of micro-EDM are its low installation cost, high accuracy and large design freedom. Micro-EDM can indeed easily machine complex 3D shapes that prove difficult for etching techniques. Next, the appropriate setting of the machining parameters in order to keep the material removal on the tool electrode at least an order of magnitude smaller than the material removal on the workpiece electrode are discussed. Micro-EDM requires electrodes as a tool A reliable method for producing these electrodes, with custom shape and small sizes is also presented. The primary applications of micro-EDM are in rapid prototyping and products with small batchsizes. However, the technique is versatile enough to be adapted to large series. Several examples are given of the possibilities of micro-EDM: an electric force motor, micromirrors at any angle with respect to the wafer plane, an acceleration sensor, and micro bevel and spur gears.

Reynaerts, Dominiek; Van Brussel, Hendrik

1997-09-01

296

Combining signal processing and machine learning techniques for real time measurement of raindrops  

Microsoft Academic Search

The data acquisition system for a new type of optical disdrometer is presented. As the device must measure sizes and velocities of raindrops as small as 0.1 mm diameter in real time in the presence of high noise and a variable baseline, algorithm design has been a challenge. The combining of standard signal processing techniques and machine learning methods (in

Bruce Denby; Jean-Christophe Prévotet; Patrick Garda; Bertrand Granado; Laurent Barthes; Peter Golé; Jacques Lavergnat; Jean-Yves Delahaye

2001-01-01

297

Molecular dynamics simulation of the precision machining process including radiative and convective heat transfer mechanisms  

Microsoft Academic Search

During the machining process, extreme temperatures can occur in the various heat generation zones of the material. These temperatures can sometimes reach or exceed the melting point. To accurately represent the influence of this heating, heat transfer mechanisms must be incorporated into simulation models. The simulation model described in this paper provides a new feature that includes heat transfer to

J. A. Patten; K. Flurchick; J. Beeler; J. Strenkowski

1994-01-01

298

Effect of processing parameters on surface finish for fused deposition machinable wax patterns  

NASA Technical Reports Server (NTRS)

This report presents a study on the effect of material processing parameters used in layer-by-layer material construction on the surface finish of a model to be used as an investment casting pattern. The data presented relate specifically to fused deposition modeling using a machinable wax.

Roberts, F. E., III

1995-01-01

299

Data-based hybrid modelling of the component placement process in pick-and-place machines  

Microsoft Academic Search

In this paper, an experimental study in the identification of the electronic component placement process in pick-and-place machines is presented. Unilateral contact and saturation phenomena characterize the hybrid dynamics of the system. Furthermore, the mode switch cannot be measured and identification algorithms for hybrid systems, that are capable of reconstructing both the modes and the switching law, must be used.

Lj. Juloski; W. P. M. H. Heemels; G. Ferrari-Trecate

300

Data-based hybrid modelling of the component placement process in pick-and-place machines  

Microsoft Academic Search

In this paper, an experimental study in the identification of the electronic component placement process in pick-and-place machines is presented. Unilateral contact and saturation phenomena characterize the hybrid dynamics of the system. Furthermore, the mode switch cannot be measured and identification algorithms for hybrid systems, that are capable of reconstructing both the modes and the switching law, must be used.

A. Lj. Juloski; W. P. M. H. Heemels; G. Ferrari-Trecate

2004-01-01

301

Processing of Clay/Epoxy Nanocomposites with a Three-Roll Mill Machine.  

National Technical Information Service (NTIS)

In the present study, a three-roll mill machine was used to disperse/ exfoliate the nanoclay particles in an epoxy matrix. The compounding process was carried out with varying mixing time and concentrations of clay particles (1 to 10 wt%). It was found th...

A. Yasmin J. L. Abot I. M. Daniel

2003-01-01

302

Design and manufacture of injection mould tool inserts produced using indirect SLS and machining processes  

Microsoft Academic Search

Purpose – The purpose of this paper is to report on the use of a combination of indirect selective laser sintering (SLS) and machining processes to create injection mould tools, an approach designed to offer the capability to create conformal cooling channels in the core\\/cavity inserts together with the levels of surface finish and accuracy required to meet typical injection

Ismet Ilyas; Chris Taylor; Kenny Dalgarno; John Gosden

2010-01-01

303

Arabidopsis EDM2 promotes IBM1 distal polyadenylation and regulates genome DNA methylation patterns.  

PubMed

DNA methylation is important for the silencing of transposons and other repetitive elements in many higher eukaryotes. However, plant and mammalian genomes have evolved to contain repetitive elements near or inside their genes. How these genes are kept from being silenced by DNA methylation is not well understood. A forward genetics screen led to the identification of the putative chromatin regulator Enhanced Downy Mildew 2 (EDM2) as a cellular antisilencing factor and regulator of genome DNA methylation patterns. EDM2 contains a composite Plant Homeo Domain that recognizes both active and repressive histone methylation marks at the intronic repeat elements in genes such as the Histone 3 lysine 9 demethylase gene Increase in BONSAI Methylation 1 (IBM1) and is necessary for maintaining the expression of these genes by promoting mRNA distal polyadenylation. Because of its role in maintaining IBM1 expression, EDM2 is required for preventing CHG methylation in the bodies of thousands of genes. Our results thus increase the understanding of antisilencing, genome methylation patterns, and regulation of alternative RNA processing by intronic heterochromatin. PMID:24248388

Lei, Mingguang; La, Honggui; Lu, Kun; Wang, Pengcheng; Miki, Daisuke; Ren, Zhizhong; Duan, Cheng-Guo; Wang, Xingang; Tang, Kai; Zeng, Liang; Yang, Lan; Zhang, Heng; Nie, Wenfeng; Liu, Pan; Zhou, Jianping; Liu, Renyi; Zhong, Yingli; Liu, Dong; Zhu, Jian-Kang

2014-01-01

304

Development of novel tungsten processing technologies for electro-chemical machining (ECM) of plasma facing components  

Microsoft Academic Search

Plasma facing components for fusion applications must exhibit long-term stability under extreme conditions, and therefore material imperfections cannot be tolerated due to a high risk of technical failures. To prevent or abolish defects in refractory metals components during the manufacturing process, some methods of electro-chemical machining as S-ECM and C-ECM were developed, enabling both the processing of smooth plain defect-free

Nils Holstein; Wolfgang Krauss; Jürgen Konys

2011-01-01

305

Progress towards a nuclear EDM measurement of Ra-225  

NASA Astrophysics Data System (ADS)

We are developing a long term program to search for the permanent electric dipole moment (EDM) of the Radium-225 nucleus. A nonzero nuclear EDM is a signature of of CP- and T-violating interactions within nuclei. Currently, the best experimental limits on these interactions are derived from EDM measurements of Mercury-199. The Ra-225 radioisotope (half-life of 15 days) is an attractive alternative because, due to its peculiar shape (octupole deformation), it is predicted to be 10^2-10^3 times more sensitive to these types of interactions than Hg-199. In our measurement scheme, Ra atoms are first laser cooled & trapped in a magneto-optical trap (MOT) and then transferred to an optical dipole trap (ODT), both of which have already been demonstrated. Currently being studied is the motion of this ODT into the science chamber and the transfer of atoms into a second ODT. We will report on progress towards measurements of atomic properties necessary for the EDM search and the EDM search itself.

Singh, Jaideep; Dietrich, M. R.; Kalita, M.; Parker, R. H.; Sulai, I. A.; Bailey, K.; Greene, J. P.; Mueller, P.; O'Connor, T. P.; Holt, R. J.; Lu, Z.-T.

2011-06-01

306

Investigation on particle generation by micro-electro discharge machining  

NASA Astrophysics Data System (ADS)

In the present work the scope of using micro-electro discharge machining (micro-EDM) technique to generate metalnanoparticles is studied and thermal conductivity of the fluid with particles generated using micro-EDM is characterized. In the experiment, aluminum workpiece is machined with an aluminum tool electrode in deionized water. 40 to 96 V is applied for machining with pulse-on duration being varied between 10 and 100 microseconds. The particle count analysis reveals that low voltage and high pulse-on duration favors formation of smaller sized particles, as predicted by the developed model. A thermal conductivity measurements show 4% rise in thermal conductivity with the sample (0.004% by wt. in deionized water) produced by micro-EDM setup.

Mitra, Sourav; Muralidhara, .; Vasa, N. J.; Singaperumal, M.

2010-02-01

307

Application of machine learning and expert systems to Statistical Process Control (SPC) chart interpretation  

NASA Technical Reports Server (NTRS)

Statistical Process Control (SPC) charts are one of several tools used in quality control. Other tools include flow charts, histograms, cause and effect diagrams, check sheets, Pareto diagrams, graphs, and scatter diagrams. A control chart is simply a graph which indicates process variation over time. The purpose of drawing a control chart is to detect any changes in the process signalled by abnormal points or patterns on the graph. The Artificial Intelligence Support Center (AISC) of the Acquisition Logistics Division has developed a hybrid machine learning expert system prototype which automates the process of constructing and interpreting control charts.

Shewhart, Mark

1991-01-01

308

A novel photochemical machining process for magnesium aerospace and biomedical microengineering applications  

NASA Astrophysics Data System (ADS)

Research was carried out to evaluate the feasibility of fabricating perforated (filigree) magnesium microcomponents with metal wire widths of the order of the metal thickness using a photochemical machining (PCM) process. Experimentally, it has been demonstrated for the first time that metal wire widths of 0.15 mm can be achieved within a 2D, 0.25 mm thick magnesium foil to fabricate microcomponents for use as micro air vehicle (MAV) wings or stents through a bespoke PCM process. This etching process differs significantly from the industrial etching process used currently to manufacture magnesium letterpress printing plates and embossing dies.

Allen, D. M.; Simpkins, M.; Almond, H.

2010-10-01

309

Modeling of the flow stress for AISI H13 Tool Steel during Hard Machining Processes  

SciTech Connect

In general, the flow stress models used in computer simulation of machining processes are a function of effective strain, effective strain rate and temperature developed during the cutting process. However, these models do not adequately describe the material behavior in hard machining, where a range of material hardness between 45 and 60 HRC are used. Thus, depending on the specific material hardness different material models must be used in modeling the cutting process. This paper describes the development of a hardness-based flow stress and fracture models for the AISI H13 tool steel, which can be applied for range of material hardness mentioned above. These models were implemented in a non-isothermal viscoplastic numerical model to simulate the machining process for AISI H13 with various hardness values and applying different cutting regime parameters. Predicted results are validated by comparing them with experimental results found in the literature. They are found to predict reasonably well the cutting forces as well as the change in chip morphology from continuous to segmented chip as the material hardness change.

Umbrello, Domenico; Rizzuti, Stefania [Department of Mechanical Engineering, University of Calabria 87036 Rende (Italy); Outeiro, Jose C. [Portuguese Catholic University, 3080-024 Figueira da Foz (Portugal); Shivpuri, Rajiv [Industrial, Welding and Systems Engineering - Ohio State University 43210 Columbus (United States)

2007-04-07

310

Modeling of the flow stress for AISI H13 Tool Steel during Hard Machining Processes  

NASA Astrophysics Data System (ADS)

In general, the flow stress models used in computer simulation of machining processes are a function of effective strain, effective strain rate and temperature developed during the cutting process. However, these models do not adequately describe the material behavior in hard machining, where a range of material hardness between 45 and 60 HRC are used. Thus, depending on the specific material hardness different material models must be used in modeling the cutting process. This paper describes the development of a hardness-based flow stress and fracture models for the AISI H13 tool steel, which can be applied for range of material hardness mentioned above. These models were implemented in a non-isothermal viscoplastic numerical model to simulate the machining process for AISI H13 with various hardness values and applying different cutting regime parameters. Predicted results are validated by comparing them with experimental results found in the literature. They are found to predict reasonably well the cutting forces as well as the change in chip morphology from continuous to segmented chip as the material hardness change.

Umbrello, Domenico; Rizzuti, Stefania; Outeiro, José C.; Shivpuri, Rajiv

2007-04-01

311

Improvement of fatigue life of electrical discharge machined AISI D2 tool steel by TiN coating  

Microsoft Academic Search

This work presents the effects of titanium nitride (TiN) coating by physical vapor deposition (PVD) on the fatigue life of AISI D2 tool steel, which was electrical discharge machined (EDM) at various machining parameters, such as pulse current and pulse-on duration. Surface hardness, surface roughness, residual stress and fatigue strength were measured. Experimental results indicate that EDM treatment has a

Y. H. Guu; H. Hocheng

2001-01-01

312

High Electric Fields in Cryogenic Liquids for EDM searches  

NASA Astrophysics Data System (ADS)

Experiments to search for the neutron's electric dipole moment (EDM) using ultracold neutrons (UCNs) stored in superfluid liquid helium are under development. In these experiments, being able to achieve a strong and stable electric field in superfluid liquid helium in the region where UCNs are stored is of critically importance because in EDM searches in general the sensitivity depends linearly on the strength of the applied electric field. However, the phenomenon of electric breakdown in liquid helium is poorly understood, and as such major R&D efforts are under way to study it for these experiments. In this talk, the current status of such R&D efforts and the implications of the finings on EDM searches and on possible other applications will be discussed.

Ito, Takeyasu

2012-10-01

313

Progress toward an EDM measurement in Ra-225  

NASA Astrophysics Data System (ADS)

We are developing an EDM search based on laser-cooled and trapped Ra-225 (half-life = 15 d) atoms. Due to octupole deformation of the nucleus, Ra-225 is predicted to be 2-3 orders of magnitude more sensitive to T-violating interactions than Hg-199, which currently sets the most stringent limits in the nuclear sector. In preparation of an EDM measurement, we have trapped radium atoms first in a MOT and then transferred them to a far-off-resonant optical dipole trap. We will report progress towards the EDM search and the measurements of relevant atomic properties. This work is supported by DOE, Office of Nuclear Physics, under contract No. DE-AC02-06CH11357.

Sulai, I. A.; Trimble, W. L.; Parker, R. H.; Bailey, K.; Greene, J. P.; Holt, R. J.; Korsch, W.; Lu, Z. T.; Mueller, P.; O'Connor, T. P.; Singh, J.

2010-03-01

314

3D Machine Vision and Additive Manufacturing: Concurrent Product and Process Development  

NASA Astrophysics Data System (ADS)

The manufacturing environment rapidly changes in turbulence fashion. Digital manufacturing (DM) plays a significant role and one of the key strategies in setting up vision and strategic planning toward the knowledge based manufacturing. An approach of combining 3D machine vision (3D-MV) and an Additive Manufacturing (AM) may finally be finding its niche in manufacturing. This paper briefly overviews the integration of the 3D machine vision and AM in concurrent product and process development, the challenges and opportunities, the implementation of the 3D-MV and AM at POLMAN Bandung in accelerating product design and process development, and discusses a direct deployment of this approach on a real case from our industrial partners that have placed this as one of the very important and strategic approach in research as well as product/prototype development. The strategic aspects and needs of this combination approach in research, design and development are main concerns of the presentation.

Ilyas, Ismet P.

2013-06-01

315

Use of maximum entropy method with parallel processing machine. [for x-ray object image reconstruction  

NASA Technical Reports Server (NTRS)

The maximum entropy method (MEM) and balanced correlation method were used to reconstruct the images of low-intensity X-ray objects obtained experimentally by means of a uniformly redundant array coded aperture system. The reconstructed images from MEM are clearly superior. However, the MEM algorithm is computationally more time-consuming because of its iterative nature. On the other hand, both the inherently two-dimensional character of images and the iterative computations of MEM suggest the use of parallel processing machines. Accordingly, computations were carried out on the massively parallel processor at Goddard Space Flight Center as well as on the serial processing machine VAX 8600, and the results are compared.

Yin, Lo I.; Bielefeld, Michael J.

1987-01-01

316

Search for a permanent EDM using laser cooled radioactive atom  

NASA Astrophysics Data System (ADS)

An Electric Dipole Moment (EDM) of the elementary particle is a good prove to observe the phenomena beyond the Standard Model. A non-zero EDM shows the violation of the time reversal symmetry, and under the CPT invariance it means the CP violation. In paramagnetic atoms, an electron EDM results in an atomic EDM enhanced by the factor of the 3rd power of the charge of the nucleus due the relativistic effects. A heaviest alkali element francium (Fr), which is the radioactive atom, has the largest enhancement factor K ~ 895. Then, we are developing a high intensity laser cooled Fr factory at Cyclotron and Radioisotope Center (CYRIC), Tohoku University to perform the search for the EDM of Fr with the accuracy of 10-29 e · cm. The important points to overcome the current accuracy limit of the EDM are to realize the high intensity Fr source and to reduce the systematic error due to the motional magnetic field and inhomogeneous applied field. To reduce the dominant component of the systematic errors mentioned above, we will confine the Fr atoms in the small region with the Magneto-Optical Trap and optical lattice using the laser cooling and trapping techniques. The construction of the experimental apparatus is making progress, and the new thermal ionizer already produces the Fr of ~106 ions/s with the primary beam intensity 200 nA. The developments of the laser system and optical equipments are in progress, and the present status and future plan of the experimental project is reported.

Sakemi, Y.; Harada, K.; Hayamizu, T.; Itoh, M.; Kawamura, H.; Liu, S.; Nataraj, H. S.; Oikawa, A.; Saito, M.; Sato, T.; Yoshida, H. P.; Aoki, T.; Hatakeyama, A.; Murakami, T.; Imai, K.; Hatanaka, K.; Wakasa, T.; Shimizu, Y.; Uchida, M.

2011-07-01

317

Process capability study of laser assisted micro milling of a hard-to-machine material  

Microsoft Academic Search

Laser assisted micro milling (LAMM) is capable of generating three-dimensional micro scale features in hard-to-machine materials. This paper compares the process capability of LAMM with conventional micro milling of a hardened tool steel. In particular, the potential advantages of LAMM over micro milling with respect to cutting forces, tool wear, material removal rate, burr formation and surface roughness are investigated

Mukund Kumar; Shreyes N. Melkote

318

An integrated, computer-assisted process planner for the machining of moulds for expanded polystyrene foam  

Microsoft Academic Search

Styrofoam materials have been used for some time as packaging for consumer goods to protect against damage during transportation and handling. The moulds for the fabrication of these materials have traditionally been made by sand-casting, a relatively inexpensive process but one which is not always cost-effective. Machined moulds, however, offer a more viable alternative. Outlines the development of a computer-automated

Sun-Woh Lye; Siang-Guan Lee; Hin-Yuen Yeong

1996-01-01

319

Neural Prediction of Product Quality Based on Pilot Paper Machine Process Measurements  

Microsoft Academic Search

\\u000a We describe a multilayer perceptron model to predict the laboratory measurements of paper quality using the instantaneous\\u000a state of the papermaking production process. Actual industrial data from a pilot paper machine was used. The final model met\\u000a its goal accuracy 95.7% of the time at best (tensile index quality) and 66.7% at worst (beta formation). We anticipate usage\\u000a possibilities in

Paavo Nieminen; Tommi Kärkkäinen; Kari Luostarinen; Jukka Muhonen

2011-01-01

320

A confidence voting process for ranking problems based on support vector machines  

Microsoft Academic Search

Abstract In this paper, we deal with ranking problems arising from various data mining applications where the major task is to train a rank-prediction model to assign every instance a rank. We flrst discuss the merits and potential disadvantages of two existing popular approaches for ranking problems: the ‘Max-Wins’ voting process based on multi-class support vector machines (SVMs) and the

Tianshi Jiao; Jiming Peng; Tamás Terlaky

2009-01-01

321

Modeling of TIG welding and abrasive flow machining processes using radial basis function networks  

Microsoft Academic Search

Input-output relationships of tungsten inert gas (TIG) welding and abrasive flow machining (AFM) processes were determined\\u000a using radial basis function networks (RBFNs). A batch mode of training was adopted to implement the principle of back-propagation\\u000a (BP) algorithm (which works based on a steepest descent algorithm) and a genetic algorithm (GA), separately. The performances\\u000a of RBFN tuned by a BP algorithm

Asfak Ali Mollah; Dilip Kumar Pratihar

2008-01-01

322

FPGA implementation of hardware processing modules as coprocessors in brain-machine interfaces  

Microsoft Academic Search

Real-time computation, portability and flexibility are crucial for practical brain-machine interface (BMI) applications. In this work, we proposed Hardware Processing Modules (HPMs) as a method for accelerating BMI computation. Two HPMs have been developed. One is the field-programmable gate array (FPGA) implementation of spike sorting based on probabilistic neural network (PNN), and the other is the FPGA implementation of neural

Dong Wang; Yaoyao Hao; Xiaoping Zhu; Ting Zhao; Yiwen Wang; Yaowu Chen; Weidong Chen; Xiaoxiang Zheng

2011-01-01

323

EDMs and the LHC: Implications of Recent Results  

NASA Astrophysics Data System (ADS)

The search for permanent electric dipole moments (EDMs) of leptons, nucleons, atoms, and molecules provides a powerful probe of CP violation both within and beyond the Standard Model. When combined with the results of new particle searches at the LHC, recent EDM search results are also testing the possibility that new TeV scale, CP-violating interactions may be responsible for the cosmic baryon asymmetry. In this talk, I discuss the implications of these results, as well as of recent theoretical work, for the origin of baryonic matter. I also comment on alternate probes provided by studies of CP-violating observables in the heavy flavor sector.

Ramsey-Musolf, Michael

2013-04-01

324

Straight hole micro EDM with a cylindrical tool using a variable capacitance method accompanied by ultrasonic vibration  

NASA Astrophysics Data System (ADS)

A micro hole machined by EDM with a cylindrical electrode has different hole entrance and exit diameters. This taper shape of the micro hole is caused both by tool wear and by eroded particles that induce secondary discharge during hole machining. In this paper, a novel method is proposed to reduce the difference between the entrance and exit diameters of the holes. The effects of feeding depth, applied capacitance and machining time on the formation of the tapered shape were observed experimentally. Based on these experiments, ultrasonic vibration was applied to reduce the secondary discharge and electrode wear, and capacitance was varied when the tool was approaching the exit of the hole. Using the proposed method, a straight micro hole was successfully fabricated.

Kim, Dong Jun; Yi, Sang Min; Lee, Young Soo; Chu, Chong Nam

2006-05-01

325

Using flower pollinating with artificial bees (FPAB) technique to determine machinable volumes in process planning for prismatic parts  

Microsoft Academic Search

Process planning (PP) has an important role in manufacturing systems design and operations. Volume decomposition and machinable\\u000a volumes (MVs) or machining features determination is the core activity in process planning. This process requires extraction\\u000a of elementary volumes (EVs), merging or clustering EVs to construct feasible MVs and finally selecting an optimal combination\\u000a of MVs. Development of MVs is an important

Mahmoud Houshmand; Din Mohammad Imani; S. T. A. Niaki

2009-01-01

326

Mechanical properties of white layers formed by different machining processes on nickel-based superalloy  

NASA Astrophysics Data System (ADS)

Nickel-based superalloys are widely used in the aerospace industry in the production of turbine discs and blades because of their good mechanical properties and great corrosion resistance at high temperature. Although very useful, these alloys are hard to machine. Their structure is responsible for rapid wear of cutting tools. Moreover, under certain machining conditions, near-surface regions of the material undergo a phase transformation resulting in the formation of a thin layer called "white etching layer" at the surface of the machined workpiece. Because turbine discs are safety critical components, no defects can be tolerated on the workpiece. Therefore, efforts should be made to ensure that this white etching layer can't influence the operating life of the workpiece and make its operation unsafe. Even if the existence of the white etching layer is well known, its mechanical properties have never been assessed in detail. In this thesis, we present a study of the mechanical (hardness and Young's modulus) and microstructural properties of white etching layers formed at the surface of nickel-based superalloy IN100 turbine discs fabricated by different machining processes. This work aims at evaluating the impact of the machining process and of fatigue on the properties of the white etching layers under study. The originality of this study primarily lies in the employed characterization technique. Using nanoindentation has allowed us to very precisely assess the variations of both the hardness and the Young's modulus along the white etching layers. Also, the use of a sophisticated indentation system has enabled the acquisition of very precise surface images of the samples and therefore to study the microstructure of the white etching layers. This research has demonstrated that the mechanical and microstructural properties of the white etching layers are closely linked to the machining conditions of the material. Therefore, our study will help researchers gain a better understanding of white etching layer formation mechanisms on IN100 nickel-based superalloy and find ways to prevent their formation: a point of crucial importance for the aerospace industry.

Proust, Edouard

327

New Fabrication Process for Monolithic Probes with Integrated Heaters for Nanothermal Machining  

NASA Astrophysics Data System (ADS)

In this study, we developed a new fabrication process for a micromachined probe. The microprobe comprised a microcantilever, a nanotip and a supporting substrate, which are monolithically made of single-crystal silicon. The fabrication process started with a bilayer silicon wafer made up of a 20-?m-thick epitaxial Si layer with strong boron doping and a 400-?m-thick bulk Si substrate. The tip with a radius of curvature of 50 nm was formed by anisotropic etching followed by oxidation sharpening. Then a cantilever beam was released by the back etching of an etch-stop Si layer. The spring constants of cantilevers ranging from 0.03 to 0.4 N/m were determined by finite element analysis (FEA), static measurement using an atomic force microscope (AFM) system and dynamic measurement using a laser Doppler vibrometer (LDV) system. Most importantly, Young’s modulus of thin-film materials could be confirmed using these methods. The developed probe was also equipped with a Pt heater to apply it to thermal machining on poly(methyl methacrylate) (PMMA) substrates. The cantilever tip was heated to above 120°C, and the successful machining of a cavity and a submicron-scale straight line was demonstrated. The development of the probes could be crucial for the submicron-scale machining of plastic materials.

Chiou, Chi-Han; Chang, Shang-Jen; Lee, Gwo-Bin; Lee, Huei-Huang

2006-01-01

328

Limitations Of The Current State Space Modelling Approach In Multistage Machining Processes Due To Operation Variations  

NASA Astrophysics Data System (ADS)

The State Space modelling approach has been recently proposed as an engineering-driven technique for part quality prediction in Multistage Machining Processes (MMP). Current State Space models incorporate fixture and datum variations in the multi-stage variation propagation, without explicitly considering common operation variations such as machine-tool thermal distortions, cutting-tool wear, cutting-tool deflections, etc. This paper shows the limitations of the current State Space model through an experimental case study where the effect of the spindle thermal expansion, cutting-tool flank wear and locator errors are introduced. The paper also discusses the extension of the current State Space model to include operation variations and its potential benefits.

Abellán-Nebot, J. V.; Liu, J.; Romero, F.

2009-11-01

329

A Measurement of the Electron edm using GdIG  

NASA Astrophysics Data System (ADS)

A measurement of the electron electric dipole moment (edm) using gadolinium iron garnet (GdIG) will be discussed. GdIG is a soft magnetic dielectric with a strong temperature -dependent contribution to its magnetization from paramagnetic gadolinium ions. Near liquid nitrogen temperatures, the Gd spins become substantially aligned when the sample is placed in a strong magnetic field. An edm of the paramagnetic ions results in a potential difference across the sample that reverses with the direction of the applied magnetic field. Recently, a calculation of the contribution of a permanent edm of the electron to this potential has been worked out in detail [1]. Realistic parameters suggest that a statistical precision on the electron edm of about 10^(-29) e-cm should be possible. This projected sensitivity is two orders of magnitude better than the best that has been achieved in other experiments [2]. [1] S. A. Kuenzi, O. P. Sushkov, V. A. Dzuba, and J. M. Cadogan, Phys. Rev. A 66, 032111 (2002) and T. N. Mukhamedjanov, V. A. Dzuba, O. P. Sushkov http://arXiv.org/abs/cond-mat/0301133. [2] B.C. Regan, E.D. Commins, C.J. Schmidt and D. DeMille, Phys. Rev. Lett. 88, 7 (2002)

Hunter, Larry; Charney, Noah; Gordon, Joel; Peck, Steve; Elliott, Oliver; McKeon, Margaret; Lamoreaux, Steve

2003-05-01

330

Effect of Short-Circuiting in Electrical Discharge Machining of Carbon Fiber Reinforced Plastics  

NASA Astrophysics Data System (ADS)

In this paper, we investigate the effects of short-circuiting on machining in order to discuss material removal in EDM of CFRP. Sinking EDM of CFRP using deionized water was carried out, and waveforms of gap voltage and current, pulse frequency and servo feed fluctuation, were measured for classifying machining situations, electrical discharge and short-circuiting. The cause of short-circuiting and the relationship between the short-circuiting ratio and material removal rate were investigated. In addition, the potential drop and temperature of short-circuiting carbon fibers were estimated with a simple model. Experimental results show that short-circuiting due to frayed carbon fibers frequently occurs in sinking EDM of CFRP. It is found that the short-circuiting contributes to the material removal in EDM of CFRP.

Ito, Akihiro; Hayakawa, Shinya; Itoigawa, Fumihiro; Nakamura, Takashi

331

Morphology and Phase Composition of Particles Produced by Electro-Discharge-Machining of Iron  

NASA Astrophysics Data System (ADS)

Towards producing metallic particles of controlled size and spherical shape, which are of technological importance, we have collected in the filters of an electro-discharge-machine (EDM) the material ejected from the surface of EDM iron pieces. The conditions of machining were varied for kerosene and water as dielectrics, using a discharge current of 25 A and duration times of 16 and 3072 ?s for kerosene and of 32, 384 and 768 ?s for water, respectively. Scanning electron microscopy was used to assess the effect of the time of discharge on the size of the particles. Mössbauer spectroscopy and X-ray diffraction revealed that for kerosene EDM particles only cementite-like carbides of diverse stoichiometry were formed. While no oxide was found for kerosene spheres, the analyses showed that besides the main fraction of ?-Fe, a small percentage of wüstite (and traces of hematite for the 384 ?s sample) formed on the water EDM ones.

Cabanillas, E. D.; Pasqualini, E. E.; López, M.; Cirilo, D.; Desimoni, J.; Mercader, R. C.

2001-05-01

332

RESIDUAL STRESS STATE AND HARDNESS DEPTH IN ELECTRIC DISCHARGE MACHINING: DE-IONIZED WATER AS DIELECTRIC LIQUID  

Microsoft Academic Search

Procedures and results of experimental work to measure residual stresses and hardness depth in electric discharge machined surfaces are presented. Layer removal method is used to express the residual stress profile as a function of depth caused by a die sinking type EDM. Thin stressed layers are removed from machined samples by electrochemical machining. Corresponding deformations due to stress relaxation

Bülent Ekmekci; Oktay Elkoca; A. Erman Tekkaya; Abdulkadir Erden

2005-01-01

333

Investigation of surface roughness in micro-electro discharge machining of nonconductive ZrO2 for MEMS application  

NASA Astrophysics Data System (ADS)

Micro-electro discharge machining technique, a noncontact machining process, is applied for drilling blind hole on nonconductive ZrO2 ceramic for MEMS application. A conductive layer of adhesive copper is applied on the workpiece surface to initiate the sparks. Kerosene is used as dielectric for creation of continuous conductive pyrolytic carbon layer on the machined surface. Experiments are conducted by varying the voltage (V), capacitance (C) and rotational speed (N). Correlating these variables a mathematical model for surface roughness (SR) is developed using Taguchi method. The results showed that the V and C are the significant parameters of SR in micro-EDM for nonconductive ZrO2 ceramic. The model also showed that SR increases with the increase of V and C.

Sabur, A.; Moudood, A.; Y Ali, M.; Maleque, M. A.

2013-12-01

334

Electrochemical machining of super-hydrophobic Al surfaces and effect of processing parameters on wettability  

NASA Astrophysics Data System (ADS)

Super-hydrophobic aluminum (Al) surfaces were successfully fabricated via electrochemical machining in neutral NaClO3 electrolyte and subsequent fluoroalkylsilane (FAS) modification. The effects of the processing time, processing current density, and electrolyte concentration on the wettability, morphology, and roughness were studied. The surface morphology, chemical composition, and wettability of the Al surfaces were investigated using scanning electron microscopy (SEM) equipped with energy-dispersive spectroscopy (EDS), white-light interferometry, roughness measurements, X-ray diffraction (XRD), Fourier-transform infrared spectrometry (FTIR), and optical contact angle measurements. The results show that hierarchical rough structures and low surface energy films were present on the Al surfaces after electrochemical machining and FAS modification. The combination of the rough structures and the low surface energy materials plays a crucial role in achieving super-hydrophobicity. Compared with the anodic oxidation and chemical etching method, the method proposed in our work does not require strong acid or alkali, and causes less harm to the environment and operators but with high processing efficiency. The rough structures required by the super-hydrophobic surfaces were obtained at 30-s processing time and the best super-hydrophobicity with 164.6? water contact angle and 2? tilting angle was obtained at 360 s. The resulting super-hydrophobic Al surfaces have a long-time stability in air and an excellent resistance to corrosive liquids.

Song, Jin-long; Xu, Wen-ji; Liu, Xin; Lu, Yao; Sun, Jing

2012-09-01

335

Optimization of laser machining process for the preparation of photomasks, and its application to microsystems fabrication  

NASA Astrophysics Data System (ADS)

Conventional photolithography normally utilizes a photomask for patterning light onto a chemical resist film. Therefore, the accuracy of microfabrication is highly dependent on the accuracy of the photomasks. Fabrication of hard masks involves the use of expensive laser pattern generators and other sophisticated machines using very high-precision stages and the necessary control instrumentation; therefore, an inexpensive strategy is highly necessary for laboratory-level fabrication. As this technology is primarily based on raster scanning of a laser beam, the mask making as such becomes a low-throughput process. A strategy of high-throughput manufacturing of hard masks with laser micromachining using a one-step exposure process of a chromated glass slide through a micromachined aluminum shadow mask is proposed. The features that are finally embedded in the mask are highly demagnified and well focused. Optimization of the laser machining process is carried out by considering all processing parameters. The features are characterized using an optical microscope, a scanning electron microscope, and a self-developed image analysis code. Geometrical methods are used to estimate the average edge roughness and feature size. We have also validated the usage of these masks by performing microfabrication on films made of photoresist.

Kumar, Avinash; Gupta, Ankur; Kant, Rishi; Akhtar, Syed Nadeem; Tiwari, Nachiketa; Ramkumar, Janakrajan; Bhattacharya, Shantanu

2013-10-01

336

Artificial neural network models for the prediction of surface roughness in electrical discharge machining  

Microsoft Academic Search

In the present paper Artificial Neural Networks (ANNs) models are proposed for the prediction of surface roughness in Electrical\\u000a Discharge Machining (EDM). For this purpose two well-known programs, namely Matlab® with associated toolboxes, as well as Netlab®, were emplo- yed. Training of the models was performed with data from an extensive series of EDM experiments on steel grades;\\u000a the proposed

Angelos P. Markopoulos; Dimitrios E. Manolakos; Nikolaos M. Vaxevanidis

2008-01-01

337

Abrasive micro-blasting to improve surface integrity of electrical discharge machined WC–Co composite  

Microsoft Academic Search

This study investigates the improvement of surface integrity of wire electrical discharge machined (EDM) WC–Co composite by abrasive micro-blasting. The thermally damaged recast layer generated by EDM has craters, cracks, and bubbles, which deteriorate the surface mechanical properties. The micro-blasting, using 6–12 and 4–20?m size SiC abrasive, enables the removal of the recast layer and is suitable for micro mechanical

Jun Qu; Albert J. Shih; Ronald O. Scattergood; Jie Luo

2005-01-01

338

Dynamic behavior analysis of drill-threading process when machining AISI Al-Si-Cu 4 alloy  

Microsoft Academic Search

Conventional threading operations involve two distinct machining processes: drilling and threading. Therefore, it is time\\u000a consuming for the tools must be changed and the workpiece has to be moved to another machine. This paper presents an analysis\\u000a of the combined process (drilling followed by threading) using a single tool for both operations: the tap-milling tool. Before\\u000a presenting the methodology used

Wisley Falco Sales; Marcelo Becker; Alexandre G. Gurgel; Jánes L. Júnior

2009-01-01

339

Determining dynamically active abrasive particles in the media used in centrifugal force assisted abrasive flow machining process  

Microsoft Academic Search

Abrasive flow machining (AFM) is a relatively new non-traditional process in which a semisolid media consisting of abrasive\\u000a particles and a flexible polymer carrier is extruded through or across the component to be machine finished. This process\\u000a is capable of providing excellent surface finishes on a wide range of simple as well as intricated shaped components. Low\\u000a material removal rate

R. S. Walia; H. S. Shan; P. Kumar

2008-01-01

340

Determination of reservoir induced earthquake using support vector machine and gaussian process regression  

NASA Astrophysics Data System (ADS)

The prediction of magnitude (M) of reservoir induced earthquake is an important task in earthquake engineering. In this article, we employ a Support Vector Machine (SVM) and Gaussian Process Regression (GPR) for prediction of reservoir induced earthquake M based on reservoir parameters. Comprehensive parameter (E) and maximum reservoir depth (H) are considered as inputs to the SVM and GPR. We give an equation for determination of reservoir induced earthquake M. The developed SVM and GPR have been compared with the Artificial Neural Network (ANN) method. The results show that the developed SVM and GPR are efficient tools for prediction of reservoir induced earthquake M.

Samui, Pijush; Kim, Dookie

2013-06-01

341

Precision Machining  

NSDL National Science Digital Library

Basic machining processes are introduced on a Web site that is devoted to engineering fundamentals (1). Descriptions and illustrations of drilling, turning, grinding, and other common processes are provided for people with little to no prior machining knowledge. A waterjet is a non-traditional machining technology that uses high pressure streams of water with abrasive additives rather than solid cutting instruments to slice through metal and other materials. An in-depth discussion of waterjet operation and applications is available from Southern Methodist University (2). Waterjets are often cited as being much more precise than traditional machining techniques. The Waterjet Video Vault (3) contains clips of waterjet machines in action. The video of the foam cutting procedure is especially interesting, as it shows how quick and accurate the machining process can be. An online guide to cross process machining, which incorporates elements from various conventional and unconventional techniques, is provided by the Mechanical Engineering Department at Columbia University (4). Some remarkable and innovative techniques that have surfaced over the past few years are outlined, including underwater laser machining and plasma-assisted machining. Entirely different and exotic machining techniques are required for creating microelectromechanical systems (MEMS) and other extremely small devices. The Caltech Micromachining Laboratory (5) maintains an archive of research highlights and papers on its homepage, including a paper on a MEMS-driven flapping wing for a palm-sized aerial vehicle. An online article from Modern Machine Shop (6) outlines some new technologies and research in the area of high speed machining. A particularly interesting section of the article describes a system developed at the University of Florida that aims to enable micromachining to achieve rotational speeds of standard machining processes, specifically up to a half million rotations per minute. Cutting edge waterjet innovations are the subject of a February 2003 feature from a publication of the Society of Manufacturing Engineers (7). Extremely high pressure nozzles are being developed to improve cutting speed, and enhanced software for controlling machine movements is also a focus of study. This news article (8) from June 20, 2003 describes an electrochemical machining process that is being used to fabricate complex nanostructures. The work, produced by German and U.S. researchers, has the potential to compete with current lithographic processes.

Leske, Cavin.

342

Metallurgical Analysis of Crack Initiation of Wire-Cut Electrical Discharge-Machined Spline Actuators Made of 17-4 PH Stainless Steel  

Microsoft Academic Search

Spline actuators made of investment cast 17-4 PH (precipitation hardening) stainless steel were found to contain micro-cracks.\\u000a The cracked actuators were subjected to optical and scanning electron microscopy and hardness testing, which revealed that\\u000a the failure occurred due to fatigue crack initiation and growth after electrical discharge machining (EDM). The rehardened\\u000a layer produced by the EDM remained after machining, and

Ahmad-Reza Etemadi; Bahram Fazel; Armin Emami

343

Comparison of artificial neural networks an support vector machines for feature selection in electrogastrography signal processing.  

PubMed

The paper describes a feature selection process applied to electrogastrogram (EGG) processing. The data set is formed by 42 EGG records from functional dyspeptic (FD) patients and 22 from healthy controls. A wrapper configuration classifier was implemented to discriminate between both classes. The aim of this work is to compare artificial neural networks (ANN) and support vector machines (SVM) when acting as fitness functions of a genetic algorithm (GA) that performs a feature selection process over some features extracted from the EGG signals. These features correspond to those that literature shows to be the most used in EGG analysis. The results show that the SVM classifier is faster, requires less memory and reached the same performance (86% of exactitude) than the ANN classifier when acting as the fitness function for the GA. PMID:21095965

Curilem, Millaray; Chacon, Max; Acuna, Gonzalo; Ulloa, Sebastian; Pardo, Carlos; Defilippi, Carlos; Madrid, Ana Maria

2010-01-01

344

Electrical discharge machining of titanium alloy (Ti 6Al 4V)  

NASA Astrophysics Data System (ADS)

In this study, the electrical discharge machining (EDM) of titanium alloy (Ti-6Al-4V) with different electrode materials namely, graphite, electrolytic copper and aluminium and process parameters such as, pulse current and pulse duration were performed to explore the influence of EDM parameters on various aspects of the surface integrity of Ti6Al4V. Scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive spectrograph (EDS) and hardness analysis were performed. The experimental results reveal that the value of material removal rate, surface roughness, electrode wear and average white layer thickness are tendency of increase with increasing current density and pulse duration. However, extremely long-pulse durations such as 200 ?s led to decrease MRR and surface roughness. Furthermore, the surface hardness is increasing due to the Ti 24C 15 carbides formed on the surface and obvious cracks are always evident in re-solidified layer when machining copper electrode. The surface crack densities and critical crack lines were determined for the tested material. The graphite electrode is beneficial on material removal rate, electrode wear and surface crack density but relatively poorer surface finish.

Hasçal?k, Ahmet; Çayda?, Ula?

2007-09-01

345

Machine Learning.  

ERIC Educational Resources Information Center

As scientists seek to develop machines that can "learn," that is, solve problems by imitating the human brain, a gold mine of information on the processes of human learning is being discovered, expert systems are being improved, and human-machine interactions are being enhanced. (SK)

Kirrane, Diane E.

1990-01-01

346

Prediction and analysis of radial overcut in holes drilled by electrochemical machining process  

NASA Astrophysics Data System (ADS)

Radial overcut predictive models using multiple regression analysis, artificial neural network and co-active neurofuzzy inference system are developed to predict the radial overcut during electrochemical drilling with vacuum extraction of electrolyte. Four process parameters, electrolyte concentration, voltage, initial machining gap and tool feed rate, are selected to develop the models. The comparison between the results of the presented models shows that the artificial neural network and co-active neuro-fuzzy inference system models can predict the radial overcut with an average relative error of nearly 5%. Main effect and interaction plots are generated to study the effects of process parameters on the radial overcut. The analysis shows that the voltage, electrolyte concentration and tool feed rate have significant effect on radial overcut, respectively, while initial machining gap has a little effect. It is also found that the increase of the voltage and electrolyte concentration increases the radial overcut and the increase of the tool feed rate decreases the radial overcut.

Tajdari, Mehdi; Chavoshi, Saeed Zare

2013-09-01

347

Simulation and fabrication of micro-scaled flow channels for metallic bipolar plates by the electrochemical micro-machining process  

Microsoft Academic Search

In order to take better advantage of metallic bipolar plates for producing metallic fuel cells and make it a feasible technology, it is essential that we have an efficient and cost effective fabrication process for creating micro-scaled flow channels. In this study, an electrochemical micro-machining (EMM) process is developed. In order to have better process control a finite element analysis

Shuo-Jen Lee; Chi-Yuan Lee; Kung-Ting Yang; Feng-Hui Kuan; Ping-Hung Lai

2008-01-01

348

Performance evaluation and rheological characterization of newly developed butyl rubber based media for abrasive flow machining process  

Microsoft Academic Search

The precision manufacturing technology always demands a good surface finish at low cost. This scenario drives both industries and research community to develop novel finishing processes. Presently, there are many techniques and one among them is abrasive flow machining (AFM) process. The media developed by optimum process variables mainly governs the performance of AFM. In the present experimental endeavor, an

Kamal K. Kar; N. L. Ravikumar; Piyushkumar B. Tailor; J. Ramkumar; D. Sathiyamoorthy

2009-01-01

349

Application of adaptive neuro-fuzzy inference system and cuckoo optimization algorithm for analyzing electro chemical machining process  

NASA Astrophysics Data System (ADS)

Electrochemical machining process (ECM) is increasing its importance due to some of the specific advantages which can be exploited during machining operation. The process offers several special privileges such as higher machining rate, better accuracy and control, and wider range of materials that can be machined. Contribution of too many predominate parameters in the process, makes its prediction and selection of optimal values really complex, especially while the process is programmized for machining of hard materials. In the present work in order to investigate effects of electrolyte concentration, electrolyte flow rate, applied voltage and feed rate on material removal rate (MRR) and surface roughness (SR) the adaptive neuro-fuzzy inference systems (ANFIS) have been used for creation predictive models based on experimental observations. Then the ANFIS 3D surfaces have been plotted for analyzing effects of process parameters on MRR and SR. Finally, the cuckoo optimization algorithm (COA) was used for selection solutions in which the process reaches maximum material removal rate and minimum surface roughness simultaneously. Results indicated that the ANFIS technique has superiority in modeling of MRR and SR with high prediction accuracy. Also, results obtained while applying of COA have been compared with those derived from confirmatory experiments which validate the applicability and suitability of the proposed techniques in enhancing the performance of ECM process.

Teimouri, Reza; Sohrabpoor, Hamed

2013-12-01

350

Combined ultrasonic and electrical discharge machining of ceramic coated nickel alloy  

Microsoft Academic Search

The paper deals with the problem of drilling small diameter (?1mm Ø) cooling holes in electrically non-conductive ceramic coated nickel alloy using combined ultrasonic machining (USM) and electrical discharge machining (EDM). Plasma sprayed “thermal barrier” coatings are of significant interest to the aerospace industry as a means of improving operating performance for some gas turbine components. Details are presented of

T. B Thoe; D. K Aspinwall; N Killey

1999-01-01

351

Numerical analysis of chip formation and shear localisation processes in machining the Ti6Al4V titanium alloy  

Microsoft Academic Search

A finite element modelling was carried out to analyse the chip morphology and adiabatic shear banding localisation processes\\u000a when high-speed machining refractory titanium alloys. A thermo-visco-plastic model for the machined material and a rigid with\\u000a thermal behaviour for the cutting tool were assumed. The study tries to understand the effect of the material behaviour on\\u000a the produced chip morphology. One

M. Calamaz; D. Coupard; M. Nouari; F. Girot

2011-01-01

352

Vacuum Electrical Breakdown Characteristics of Oxygen-free Copper Electrodes Processed by Precision Machining in Clean Space  

Microsoft Academic Search

The vacuum electrical breakdown characteristics of oxygen-free copper electrodes, which were processed by precision diamond turning machining in a clean room and were heat-treated in hydrogen after that machining, were investigated by applying impulse voltage. These electrodes were carried in mobile vacuum chamber in order to keep them clean. The surface conditions were analyzed by the X-ray Photoelectron Spectroscopy (XPS)

Takashi Yamamoto; Takahiro Otsuka; Yasushi Yamano; Shinichi Kobayashi; Toshiyasu Higo; Nobukazu Toge; Koji Takata; Yasuo Higashi; Yoshio Saito; Nobuteru Hitomi

2003-01-01

353

Optical dipole trapping of radium atoms for EDM search  

NASA Astrophysics Data System (ADS)

We are developing an EDM search based on laser-cooled and trapped Ra-225 (half-life = 15 d) atoms. Due to octupole deformation of the nucleus, Ra-225 is predicted to be 2-3 orders of magnitude more sensitive to T-violating interactions than Hg-199, which currently sets the most stringent limits in the nuclear sector. Recently, we have succeeded in transferring Ra-226 atoms from a MOT into an optical dipole trap formed by a fiber laser beam at 1550 nm. For the EDM measurement, the cold atoms will be moved into the neighboring vacuum chamber inside magnetic shields where a pair of electrodes apply a 10 kV cm-1electric field. This work is supported by DOE, Office of Nuclear Physics under contract No. DE-AC02-06CH11357.

Trimble, W. L.; Sulai, I. A.; Parker, R. H.; Bailey, K.; Greene, J. P.; Holt, R. J.; Korsch, W.; Lu, Z.-T.; Mueller, P.; O'Connor, T. P.; Singh, J.

2010-03-01

354

Evaluation of a Prototype Fish Cleaning Machine with Proposals for a Commercial Processing Line.  

National Technical Information Service (NTIS)

A prototype heading and cleaning machine for small whiting was evaluated under commercial conditions. The major finding was that the machine is sound in theory and principle but needs some of its components redesigned for high speed production. Throughput...

J. M. Mendelsohn J. G. Callan

1980-01-01

355

An in-process form error measurement system for precision machining  

NASA Astrophysics Data System (ADS)

In-process form error measurement for precision machining is studied. Due to two key problems, opaque barrier and vibration, the study of in-process form error optical measurement for precision machining has been a hard topic and so far very few existing research works can be found. In this project, an in-process form error measurement device is proposed to deal with the two key problems. Based on our existing studies, a prototype system has been developed. It is the first one of the kind that overcomes the two key problems. The prototype is based on a single laser sensor design of 50 nm resolution together with two techniques, a damping technique and a moving average technique, proposed for use with the device. The proposed damping technique is able to improve vibration attenuation by up to 21 times compared to the case of natural attenuation. The proposed moving average technique is able to reduce errors by seven to ten times without distortion to the form profile results. The two proposed techniques are simple but they are especially useful for the proposed device. For a workpiece sample, the measurement result under coolant condition is only 2.5% larger compared with the one under no coolant condition. For a certified Wyko test sample, the overall system measurement error can be as low as 0.3 µm. The measurement repeatability error can be as low as 2.2%. The experimental results give confidence in using the proposed in-process form error measurement device. For better results, further improvement in design and tests are necessary.

Gao, Y.; Huang, X.; Zhang, Y.

2010-05-01

356

Six-Axis Electrical-Discharge Machine: Versatile machine tool is made by converting a radial drill.  

National Technical Information Service (NTIS)

This citation summarizes a one-page announcement of technology available for utilization. An electrical-discharge machine (EDM) of unusual versatility has been made by the conversion of a radial drill. The drilling head is replaced by a ram that holds and...

1983-01-01

357

Incorporating Lamination Processing and Component Manufacturing in Electrical Machine Design Tools  

Microsoft Academic Search

Measures to improve the modeling of steel-sheet laminations in electrical machine design tools are studied. Only the magnetic properties, namely, the permeability (BH curves) and the iron losses are addressed. The sensitivity of these properties upon dimensional, directional (anisotropy) and excitation variations, as well as upon the electrical machines manufacturing steps is evaluated. The studied electrical machines manufacturing step are:

Waqas M. Arshad; Thomas Ryckebusch; F. Magnussen; H. Lendenmann; Bengt Eriksson; J. Soulard; B. Malmros

2007-01-01

358

Search for a permanent EDM in ^199Hg.  

NASA Astrophysics Data System (ADS)

The most stringent limit on CP-violating nuclear interactions comes from the search for an Electric Dipole Moment of ^199Hg [J.P. Jacobs, et al. Phys. Rev. A 52, 3521, (1995)]. We are working on the next generation of this experiment. The experiment uses a tunable UV laser for optical pumping of Hg at 254 nm. Significant improvements have been made to the detector efficiency and ^199Hg vapor cells. Systematic effects are reduced by using the rotation of linearly polarized off-resonant light to detect the spin precession of the Hg atoms. Recently we performed a detailed study of the electric field in the cells using the Stark shift of the 6^1S0 arrow 6^3P1 Hg transition. We measured, for the first time, the scalar Stark shift of this transition. It is equal to 3.34(6) kHz/(kV/cm^2). The accuracy of the Hg atomic theory is presently one of the limiting factors in the interpretation of the EDM limit. If the theory is improved, the Stark shift can be used as a check of the calculations. We are presently accumulating EDM data and checking for systematic errors. A preliminary result on the ^199Hg EDM will be reported.

Romalis, M. V.; Griffith, W. C.; Harber, D.; Heckel, B. R.; Fortson, E. N.; Jacobs, J. P.

2000-06-01

359

Electromechanical Machining.  

National Technical Information Service (NTIS)

The purpose of this work was to adapt the new process of electromechanical machining (EMM), in which metal is cut by direct contact of the tool with an electrochemically polarized workpiece, to turning and drilling. This investigation, which followed expe...

R. M. Latanision K. C. Nielsen

1976-01-01

360

Process Simulation Assisted Fabricating Micro-Herringbone Grooves for a Hydrodynamic Bearing in Electrochemical MicroMachining  

Microsoft Academic Search

This study presents the process simulation of fabricating a herringbone groove in a hydrodynamic bearing by Electrochemical Micro-Machining (EMM) process. The finite element simulation involved the multi-physics of a chemical reaction, a static electrical field and electric current density. A dedicated EMM system was established for this study. The groove pattern on the cathode tool was transferred to the internal

Dar-Yuan Chang; Ping-Chen Shen; Jung-Chou Hung; Shuo-Jen Lee; Hai-Ping Tsui

2011-01-01

361

Architecture For The Optimization Of A Machining Process In Real Time Through Rule-Based Expert System  

Microsoft Academic Search

Under the project SENSOR-IA which has had financial funding from the Order of Incentives to the Regional Technology Centers of the Counsil of Innovation, Science and Enterprise of Andalusia, an architecture for the optimization of a machining process in real time through rule-based expert system has been developed. The architecture consists of an acquisition system and sensor data processing engine

Rafael Serrano; Luis Carlos González; Francisco Jesús Martín

2009-01-01

362

Image processing with genetic algorithm in a raisin sorting system based on machine vision  

NASA Astrophysics Data System (ADS)

This study was undertaken to develop machine vision-based raisin detection technology. Supervised color image segmentation using a Permutation-coded Genetic Algorithm (GA) identifying regions in Hue-Saturation-Intensity (HSI) color space (GAHSI) for desired and undesired raisin detection was successfully implemented. Images were captured to explore the possibility of using GAHSI to locate desired raisin and undesired raisin regions in color space simultaneously. In this research, images were processed separately using three segmentation method, K-Means clustering in L*a*b* color space and GAHSI for single image, GA for single image in Red-Green-Blue (RGB) color space (GARGB). The GAHSI results provided evidence for the existence and separability of such regions. When compared with cluster analysis-based segmentation results, the GAHSI method showed no significant difference.

Abbasgholipour, Mahdi; Alasti, Behzad Mohammadi; Abbasgholipour, Vahdi; Derakhshan, Ali; Abbasgholipour, Mohammad; Rahmatfam, Sharmin; Rahmatfam, Sheyda; Habibifar, Rahim

2012-04-01

363

Evaluation of surface water resources from machine-processing of ERTS multispectral data  

NASA Technical Reports Server (NTRS)

The surface water resources of a large metropolitan area, Marion County (Indianapolis), Indiana, are studied in order to assess the potential value of ERTS spectral analysis to water resources problems. The results of the research indicate that all surface water bodies over 0.5 ha were identified accurately from ERTS multispectral analysis. Five distinct classes of water were identified and correlated with parameters which included: degree of water siltiness; depth of water; presence of macro and micro biotic forms in the water; and presence of various chemical concentrations in the water. The machine processing of ERTS spectral data used alone or in conjunction with conventional sources of hydrological information can lead to the monitoring of area of surface water bodies; estimated volume of selected surface water bodies; differences in degree of silt and clay suspended in water and degree of water eutrophication related to chemical concentrations.

Mausel, P. W.; Todd, W. J.; Baumgardner, M. F.; Mitchell, R. A.; Cook, J. P.

1976-01-01

364

Modeling of Electrical Discharge Machining Process Using Conventional Regression Analysis and Genetic Algorithms  

NASA Astrophysics Data System (ADS)

An attempt was made to model input-output relationships of an electrical discharge machining process based on the experimental data (collected according to a central composite design) using multiple regression analysis. Three input parameters, such as peak current, pulse-on-time and pulse-duty-factor, and two outputs, namely, material removal rate (MRR) and surface roughness (SR) had been considered for the said modeling. The value of regression coefficient was determined for each model. The performances of the developed models were tested with the help of some test cases collected through the real experiments and were found to be satisfactory. It had been posed as an optimization problem and solved using a genetic algorithm to determine the set(s) of optimal parameters for ensuring the maximum MRR and minimum SR. It was also formulated as a multi-objective optimization problem and a Pareto-optimal front of solutions had been obtained.

Maji, Kuntal; Pratihar, Dilip Kumar

2011-10-01

365

Hybrid Metaheuristics for Solving a Fuzzy Single Batch-Processing Machine Scheduling Problem  

PubMed Central

This paper deals with a problem of minimizing total weighted tardiness of jobs in a real-world single batch-processing machine (SBPM) scheduling in the presence of fuzzy due date. In this paper, first a fuzzy mixed integer linear programming model is developed. Then, due to the complexity of the problem, which is NP-hard, we design two hybrid metaheuristics called GA-VNS and VNS-SA applying the advantages of genetic algorithm (GA), variable neighborhood search (VNS), and simulated annealing (SA) frameworks. Besides, we propose three fuzzy earliest due date heuristics to solve the given problem. Through computational experiments with several random test problems, a robust calibration is applied on the parameters. Finally, computational results on different-scale test problems are presented to compare the proposed algorithms.

Molla-Alizadeh-Zavardehi, S.; Tavakkoli-Moghaddam, R.; Lotfi, F. Hosseinzadeh

2014-01-01

366

FPGA implementation of hardware processing modules as coprocessors in brain-machine interfaces.  

PubMed

Real-time computation, portability and flexibility are crucial for practical brain-machine interface (BMI) applications. In this work, we proposed Hardware Processing Modules (HPMs) as a method for accelerating BMI computation. Two HPMs have been developed. One is the field-programmable gate array (FPGA) implementation of spike sorting based on probabilistic neural network (PNN), and the other is the FPGA implementation of neural ensemble decoding based on Kalman filter (KF). These two modules were configured under the same framework and tested with real data from motor cortex recording in rats performing a lever-pressing task for water rewards. Due to the parallelism feature of FPGA, the computation time was reduced by several dozen times, while the results are almost the same as those from Matlab implementations. Such HPMs provide a high performance coprocessor for neural signal computation. PMID:22255365

Wang, Dong; Hao, Yaoyao; Zhu, Xiaoping; Zhao, Ting; Wang, Yiwen; Chen, Yaowu; Chen, Weidong; Zheng, Xiaoxiang

2011-01-01

367

Hybrid metaheuristics for solving a fuzzy single batch-processing machine scheduling problem.  

PubMed

This paper deals with a problem of minimizing total weighted tardiness of jobs in a real-world single batch-processing machine (SBPM) scheduling in the presence of fuzzy due date. In this paper, first a fuzzy mixed integer linear programming model is developed. Then, due to the complexity of the problem, which is NP-hard, we design two hybrid metaheuristics called GA-VNS and VNS-SA applying the advantages of genetic algorithm (GA), variable neighborhood search (VNS), and simulated annealing (SA) frameworks. Besides, we propose three fuzzy earliest due date heuristics to solve the given problem. Through computational experiments with several random test problems, a robust calibration is applied on the parameters. Finally, computational results on different-scale test problems are presented to compare the proposed algorithms. PMID:24883359

Molla-Alizadeh-Zavardehi, S; Tavakkoli-Moghaddam, R; Lotfi, F Hosseinzadeh

2014-01-01

368

Comparison of support vector machine-based processing chains for hyperspectral image classification  

NASA Astrophysics Data System (ADS)

Many different approaches have been proposed in recent years for remotely sensed hyperspectral image classification. Despite the variety of techniques designed to tackle the aforementioned problem, the definition of standardized processing chains for hyperspectral image classification is a difficult objective, which may ultimately depend on the application being addressed. Generally speaking, a hyperspectral image classification chain may be defined from two perspectives: 1) the provider's viewpoint, and 2) the user's viewpoint, where the first part of the chain comprises activities such as data calibration and geo-correction aspects, while the second part of the chain comprises information extraction processes from the collected data. The modules in the second part of the chain (which constitutes our main focus in this paper) should be ideally flexible enough to be accommodated not only to different application scenarios, but also to different hyperspectral imaging instruments with varying characteristics, and spatial and spectral resolutions. In this paper, we evaluate the performance of different processing chains resulting from combinations of modules for dimensionality reduction, feature extraction/ selection, image classification, and spatial post-processing. The support vector machine (SVM) classifier is adopted as a baseline due to its ability to classify hyperspectral data sets using limited training samples. A specific classification scenario is investigated, using a reference hyperspectral data set collected by NASA's Airborne Visible Infra-Red Imaging Spectrometer (AVIRIS) over the Indian Pines region in Indiana, USA.

Rojas, Marta; Dópido, Inmaculada; Plaza, Antonio; Gamba, Paolo

2010-08-01

369

Optimizing target surfaces for inertial confinement fusion experiments using micro-electrical discharge machining  

NASA Astrophysics Data System (ADS)

Cone guided fast-ignition laser fusion uses a re-entrant cone target to allow laser access through the plasma overlying the compressed core. Current experiments emulate that situation with a conical hole in an aluminum foil. It is critical that the 10 ?m diameter laser spot be centered on the 30 ?m diameter flat cone tip. Alignment is achieved by retro-imaging a low power beam from the cone tip. Micron scale roughness on the cone tip limits reflected light intensity making alignment difficult; an improved surface finish is required. The buried cone targets are fabricated by micro-electrical discharge machining (EDM). Various parameters are investigated to decrease the roughness and to improve the uniformity of the EDM cone tip surface: EDM wire material and shape, electrode voltage, machine capacitance, and machining speed. Results of surface roughness, uniformity, and material removal rate will be presented.

Waltz, C.; Jaquez, J. J.

2011-11-01

370

Machine processing of S-192 and supporting aircraft data: Studies of atmospheric effects, agricultural classifications, and land resource mapping  

NASA Technical Reports Server (NTRS)

Two tasks of machine processing of S-192 multispectral scanner data are reviewed. In the first task, the effects of changing atmospheric and base altitude on the ability to machine-classify agricultural crops were investigated. A classifier and atmospheric effects simulation model was devised and its accuracy verified by comparison of its predicted results with S-192 processed results. In the second task, land resource maps of a mountainous area near Cripple Creek, Colorado were prepared from S-192 data collected on 4 August 1973.

Thomson, F.

1975-01-01

371

One-step process for superhydrophobic metallic surfaces by wire electrical discharge machining.  

PubMed

We present a direct one-step method to fabricate dual-scale superhydrophobic metallic surfaces using wire electrical discharge machining (WEDM). A dual-scale structure was spontaneously formed by the nature of exfoliation characteristic of Al 7075 alloy surface during WEDM process. A primary microscale sinusoidal pattern was formed via a programmed WEDM process, with the wavelength in the range of 200 to 500 ?m. Notably, a secondary roughness in the form of microcraters (average roughness, Ra: 4.16 to 0.41 ?m) was generated during the exfoliation process without additional chemical treatment. The low surface energy of Al 7075 alloy (? = 30.65 mJ/m(2)) together with the presence of dual-scale structures appears to contribute to the observed superhydrophobicity with a static contact angle of 156° and a hysteresis less than 3°. To explain the wetting characteristics on dual-scale structures, we used a simple theoretical model. It was found that Cassie state is likely to present on the secondary roughness in all fabricated surfaces. On the other hand, either Wenzel or Cassie state can present on the primary roughness depending on the characteristic length of sinusoidal pattern. In an optimal condition of the serial cutting steps with applied powers of ?30 and ?8 kW, respectively, a stable, superhydrophobic metallic surface was created with a sinusoidal pattern of 500 ?m wavelength. PMID:22732181

Bae, Won Gyu; Song, Ki Young; Rahmawan, Yudi; Chu, Chong Nam; Kim, Dookon; Chung, Do Kwan; Suh, Kahp Y

2012-07-25

372

Investigation of a novel hybrid process of laser drilling assisted with jet electrochemical machining  

NASA Astrophysics Data System (ADS)

Recast layer and spatter are two inherent defects commonly associated with holes produced with laser drilling. This paper reports a novel hybrid process of laser drilling assisted with jet electrochemical machining (JECM-LD) that aims to minimize such defects and improve the quality of laser-drilled holes. The process based on the application of a jet electrolyte, being aligned coaxially with the focused laser beam, on the workpiece surface during laser drilling. The effect of the jet electrolyte mainly is an electrochemical reaction with materials. The jet electrolyte also cools the workpiece and transports debris during the process. On the basis of a measurement of laser attenuation in electrolyte, an experimental apparatus system is made and JECM-LD experiments have been performed on 0.5-mm-thick 321S20 stainless steel with two lasers at wavelength of 1064 and 532 nm. It is shown that recast layer and spatter have been effectively reduced during the JECM-LD compared with laser drilling in ambient atmosphere conditions.

Zhang, Hua; Xu, Jiawen; Wang, Jiming

2009-11-01

373

Combined Sensor Package COMARS+ for Measuring Aerothermal and Radiation Loads on the Exomars EDM Capsule Back Cover  

NASA Astrophysics Data System (ADS)

Based on the former flight instrumentation experience combined aerothermal sensor package COMARS+ has been developed to perform radiative and convective heat flux measurements on the EDM back cover TPS of ExoMars EDM flight in 2016.

Guelhan, A.; Siebe, F.; Thiele, T.

2014-06-01

374

Experimental investigations on induction machine condition monitoring and fault diagnosis using digital signal processing techniques  

Microsoft Academic Search

Condition monitoring is used for increasing machinery availability and machinery performance, reducing consequential damage, increasing machine life, reducing spare parts inventories, and reducing breakdown maintenance. An efficient condition monitoring scheme is capable of providing warning and predicting the faults at early stages. The monitoring system obtains information about the machine in the form of primary data and through the use

Sa'ad Ahmed Saleh Al Kazzaz; G. K Singh

2003-01-01

375

{sup 3}He MAGNETOMETRY FOR A NEUTRON EDM MEASUREMENT  

SciTech Connect

The behavior of small amounts of polarized {sup 3}He in a bath of superfluid {sup 4}He at temperatures below 1 K is critical to a new technique for measuring the EDM of the neutron. We report on studies to enhance the number of ultracold neutrons produced in such a bath, on the development of neutron tomography in gaseous mixtures, on magnet properties associated with the precession of {sup 3}He, and on preparations for tests of the distribution and diffusion coefficients of {sup 3}He in the bath.

P. BANGERT; ET AL

2000-08-01

376

Multiconfiguration Dirac-Hartree-Fock calculations of EDM for Ra, Hg, Yb  

NASA Astrophysics Data System (ADS)

Using multiconfiguration Dirac-Hartree-Fock (MCDHF) method, we calculated the atomic electric dipole moment (EDM) for Ra, Hg, Yb, arising from nuclear Schiff moment, (P,T)-odd electron-nucleon interactions, and interaction of electron EDM with nuclear electromagnetic field.

Gaigalas, Gediminas; Biero?, Jacek; Radži?t?, Laima

2014-04-01

377

Investigation of micro-EDM material removal characteristics using single RC-pulse discharges  

Microsoft Academic Search

Similar to EDM, in micro-EDM, intense heat is generated between the workpiece and tool electrode by the discharge through a dielectric medium to result in the formation of a microcrater that is much smaller in size. In this study, a single-spark generator has been developed to study the erosion characteristics from the microcrater size. Using a simple heat transfer model,

Y. S Wong; M Rahman; H. S Lim; H Han; N Ravi

2003-01-01

378

Energy Models for Denmark EXPLOR-EDM Case Studies Base and High Case.  

National Technical Information Service (NTIS)

The input-output model (EXPLOR) and the energy demand model (EDM) are implemented for Denmark for the years 1970, 1973, 1974, 1980, 1985 and 1990, where 1970 is chosen as base year. The models have been modified and improved. The EDM-model has been almost...

P. E. Morthorst

1981-01-01

379

Tool vibration detection with eddy current sensors in machining process and computation of stability lobes using fuzzy classifiers  

Microsoft Academic Search

Today the knowledge of a process is very important for engineers to find optimal combination of control parameters warranting productivity, quality and functioning without defects and failures. In our laboratory, we carry out research in the field of high speed machining with modelling, simulation and experimental approaches. The aim of our investigation is to develop a software allowing the cutting

Arnaud Devillez; Daniel Dudzinski

2007-01-01

380

Influence and evaluation of non-ideal manufacturing process on the cogging torque of a permanent magnet excited synchronous machine  

Microsoft Academic Search

Purpose – The purpose of this paper is to describe how a minimisation of cogging torque is performed with respect to the non-ideal manufacturing process, aiming at a robust design of the studied machine, focusing on magnetisation faults and the use of different qualities of the permanent magnet material. Design\\/methodology\\/approach – The applied methodology is a combination of design of

Isabel Coenen; Mercedes Herranz Gracia; Kay Hameyer

2011-01-01

381

Sandia's search for environmentally sound cleaning processes for the manufacture of electronic assemblies and precision machined parts  

Microsoft Academic Search

As part of the DOE's commitment to minimizing waste at the national laboratories and its production agencies, Sandia has embarked on a program to reduce, and where feasible, eliminate hazardous liquid waste by-products of cleaning processes used in the manufacture of electronic assemblies and precision machined parts. The program is being carried out in conjunction with three DOE production agencies:

M. C. Oborny; E. P. Lopez; D. R. Frear; M. G. Benkovich; R. F. Salerno; J. V. Dichiaro; D. R. Ostheim; R. Jr. Waterbury

1990-01-01

382

Modelling the surface roughness behaviour of an EDMed workpiece with different tool electrodes using DoE  

NASA Astrophysics Data System (ADS)

Surface roughness of a workpiece is one of the measures used in evaluating the performance of any machining technique. In this paper, the behaviour of a post-EDM roughness of mild steel material subjected to machining with two different electrodes is evaluated through modelling using three machining variables. The variables are peak current, pulse on-time and pulse off-time, while the electrodes used are Cu-TaC compact green electrode and metallic Cu. The investigation was planned and analysed with Design of Experiment (DoE) in which the output response obtained with the two electrodes were compared. Results indicate that the roughness obtained with Cu-TaC electrode is a function of peak current, pulse on-time, pulse off-time with interaction between on-time and off time, whereas that of metallic Cu electrode is related with current and pulse on-time only. Further more, the metallic Cu electrode produced comparatively lower roughness under all the machining conditions. The lowest roughness obtained with Cu-TaC electrode is over 100% higher than that of Cu-electrode.

Ndaliman, M. B.; Khan, A. A.; Y Ali, M.; Hambiyah, M. A. Mohammad

2013-12-01

383

Effect of composition and processing on the thermal fatigue and toughness of high performance die steels. Final report  

SciTech Connect

The objective of this study was to improve average die life by optimizing die steel composition and the die processing. Four different steels, K,Q,C and Premium Grade H-13 have been investigated for thermal fatigue resistance and toughness. Optimum heat treatment processing has been determined for each steel with respect to austenitizing temperature and tempering conditions. The effect of the quenching rate on the thermal fatigue resistance and toughness of the die steels and the effect of Electro-Discharge Machining (EDM) on the thermal fatigue resistance were also determined. The immersion thermal fatigue specimen developed at CWRU was used to determine the thermal fatigue resistance as characterized by the two parameters of average maximum crack length and total crack area. The Charpy V-notch impact test was used over a -100{degrees}F to 450{degrees}F testing temperature range to evaluate the toughness and the brittle-ductile transition behavior. K steel has been identified as superior in performance compared to Premium Grade H-13. Q and C provide lower toughness and thermal fatigue resistance than H-13. Faster cooling rates provide higher thermal fatigue resistance and toughness. Higher austenitizing temperatures such as 1925{degrees}F compared to 1875{degrees}F provide better thermal fatigue resistance, but lower austenitizing temperatures of 1875{degrees}F provide better toughness. Higher hardness improves thermal fatigue resistance, but reduces toughness. A minimum of Rc 46 hardness is desired for aluminum die casting dies. EDM reduces the thermal fatigue resistance compared to conventional machining operations. When the EDM process of multiple small steps of decreasing energy and post-EDM treatments are employed, the effect can be reduced to a very slight amount. Preliminary evidence of the superior performance of the K steel has been provided by ongoing field testing of inserts in multiple cavity dies.

Wallace, J.F.; Wang, Y.; Schwam, D.

1997-06-01

384

The Influence of EDM Parameters in Finishing Stage on Surface Quality of Hot Work Steel Using Artificial Neural Network  

NASA Astrophysics Data System (ADS)

In this paper, the influence of different EDM parameters (pulse current, pulse voltage, pulse on-time , pulse off-time) in finishing stage on the surface quality (Ra) as a result of application copper electrode to a work piece( hot work steel DIN1.2344) has been investigated. Design of the experiment was chosen full factorial. Statistical analysis has been done and artificial neural network has been used to choose proper machining parameters and to reach certain surface roughness. Finally a hybrid model has been designed to reduce the artificial neural network errors. The experiment results indicated a good performance of proposed method in optimization of such a complex and non-linear problems.

Amini, S.; Atefi, R.; Solhjoei, N.

2011-01-01

385

Investigation into the effect of overlap factors and process parameters on surface roughness and machined depth during micro-turning process with Nd:YAG laser  

NASA Astrophysics Data System (ADS)

One of the emerging laser material processing technologies to process cylindrical shaped materials is the laser micro-turning process. This process is used to machine micro-turned groove or surface on the difficult-to-process materials for a specific length of turn along its axis. The present experimental study investigates the laser micro-turning operation of a cylindrical shaped aluminum oxide (Al2O3) ceramic to explore the effect of successive spot overlap and circumferential overlap on the surface roughness (Ra) criterion. Moreover, depth of machining has also been studied by varying various process parameters such as pulse frequency, workpiece rotating speed and laser beam average power. Various amounts of spot overlap have been accomplished by different combined settings of related parameters i.e. workpiece rotating speed and pulse frequency. In contrast, various circumferential overlap between successive rotational scan widths have been achieved by varying the rotational speed and also axial feed rate of the workpiece. Surface roughness (Ra) and machined depth have been measured as output response for machining at various parametric combinations. Analyses have been made through different plots of surface roughness (Ra) and machined depth to study the influence of these overlaps and different process parameters. The experimental results revealed that surface roughness decreases with the increase of both the overlap factors. It is observed from the results that with the increase in circumferential overlap, roughness of the machined surface decreases for each workpiece rotating speed setting. Further, wide spot crater is achieved at a higher value of average power. Minimum surface roughness is achieved as 5.25 µm at average power 10 W, pulse frequency 3000 Hz, workpiece rotating speed 400 rpm and Y feed rate 0.3 mm/s. The achieved machined depth is high at a low speed of rotation and pulse frequency settings. With the increase of average power of laser beam, the machined depth is found to increase linearly. The maximum micro-turning depth is achieved as 0.146 mm at parametric combination of average power of 10 W, pulse frequency of 3000 Hz, workpiece rotating speed of 400 rpm and Y feed rate of 0.3 mm/s.

Kibria, G.; Doloi, B.; Bhattacharyya, B.

2014-08-01

386

Tool vibration detection with eddy current sensors in machining process and computation of stability lobes using fuzzy classifiers  

NASA Astrophysics Data System (ADS)

Today the knowledge of a process is very important for engineers to find optimal combination of control parameters warranting productivity, quality and functioning without defects and failures. In our laboratory, we carry out research in the field of high speed machining with modelling, simulation and experimental approaches. The aim of our investigation is to develop a software allowing the cutting conditions optimisation to limit the number of predictive tests, and the process monitoring to prevent any trouble during machining operations. This software is based on models and experimental data sets which constitute the knowledge of the process. In this paper, we deal with the problem of vibrations occurring during a machining operation. These vibrations may cause some failures and defects to the process, like workpiece surface alteration and rapid tool wear. To measure on line the tool micro-movements, we equipped a lathe with a specific instrumentation using eddy current sensors. Obtained signals were correlated with surface finish and a signal processing algorithm was used to determine if a test is stable or unstable. Then, a fuzzy classification method was proposed to classify the tests in a space defined by the width of cut and the cutting speed. Finally, it was shown that the fuzzy classification takes into account of the measurements incertitude to compute the stability limit or stability lobes of the process.

Devillez, Arnaud; Dudzinski, Daniel

2007-01-01

387

Efficient production by laser-materials-processing integrated into metal cutting machines  

Microsoft Academic Search

Beam guidance of high power YAG-laser (cw, pulsed, Q-switched) with average powers up to 2000 W by flexible glass fibers facilitates the integration of the laser beam as an additional tool into metal cutting machines. Hence, technologies like laser cutting, joining, hardening, caving, structuring of surfaces and laser-marking can be applied directly inside machining centers in one setting, thereby reducing

M. Wiedmaier; E. Meiners; Friedrich Dausinger; Helmut Huegel

1994-01-01

388

MULTI-OBJECTIVE OPTIMIZATION OF ABRASIVE FLOW MACHINING PROCESSES USING POLYNOMIAL NEURAL NETWORKS AND GENETIC ALGORITHMS  

Microsoft Academic Search

Abrasive flow machining (AFM) is an economic and effective non-traditional machining technique, which is capable of providing excellent surface finish on difficult to approach regions on a wide range of components. With this method, it has become possible to substitute various time-consuming deburring and polishing operations that had often lead to non-reproducible results. In this paper, group method of data

M. Ali-Tavoli; N. Nariman-Zadeh; A. Khakhali; M. Mehran

2006-01-01

389

Feasibility demonstration of using wire electrical-discharge machining, abrasive flow honing, and laser spot welding to manufacture high-precision triangular-pitch Zircaloy-4 fuel-rod-support grids  

SciTech Connect

Results are reported supporting the feasibility of manufacturing high precision machined triangular pitch Zircaloy-4 fuel rod support grids for application in water cooled nuclear power reactors. The manufacturing processes investigated included wire electrical discharge machining of the fuel rod and guide tube cells in Zircaloy plate stock to provide the grid body, multistep pickling of the machined grid to provide smooth and corrosion resistant surfaces, and laser welding of thin Zircaloy cover plates to both sides of the grid body to capture separate AM-350 stainless steel insert springs in the grid body. Results indicated that dimensional accuracy better than +- 0.001 and +- 0.002 inch could be obtained on cell shape and position respectively after wire EDM and surface pickling. Results on strength, corrosion resistance, and internal quality of laser spot welds are provided.

Horwood, W.A.

1982-05-01

390

Architecture For The Optimization Of A Machining Process In Real Time Through Rule-Based Expert System  

NASA Astrophysics Data System (ADS)

Under the project SENSOR-IA which has had financial funding from the Order of Incentives to the Regional Technology Centers of the Counsil of Innovation, Science and Enterprise of Andalusia, an architecture for the optimization of a machining process in real time through rule-based expert system has been developed. The architecture consists of an acquisition system and sensor data processing engine (SATD) from an expert system (SE) rule-based which communicates with the SATD. The SE has been designed as an inference engine with an algorithm for effective action, using a modus ponens rule model of goal-oriented rules.The pilot test demonstrated that it is possible to govern in real time the machining process based on rules contained in a SE. The tests have been done with approximated rules. Future work includes an exhaustive collection of data with different tool materials and geometries in a database to extract more precise rules.

Serrano, Rafael; González, Luis Carlos; Martín, Francisco Jesús

2009-11-01

391

Automatic River Bed Grain Size Measurement Using Image Processing and Support Vector Machines  

NASA Astrophysics Data System (ADS)

Gravel-bedded rivers cut through hilly and mountainous areas, driving landscape evolution and creating a diverse habitat upon which river food web ecosystems develop. Our understanding of the mechanics underlying important processes in fluvial geomorphology, hydrodynamics, and aquatic ecology inevitably requires knowledge about the grain size distribution of river bed material. Standard methods of sampling bed surface material may introduce errors due to biases and inadequate sample size. Alternative areal or volumetric sampling procedures are often impractical, particularly in coarse channel beds. Furthermore, all invasive sampling techniques can compromise laboratory flume experiments. These concerns suggest that there is a practical need for a reliable, automated, non-invasive procedure for obtaining the grain size distribution of bed surface material. Although considerable effort has been made to automatically generate grain size distributions using image processing and analysis techniques, the problem remains quite challenging: issues such as varying lighting conditions, partial immersion of particles in water, and heterogeneous mineralogy result in ambiguities that cannot be easily resolved. Feature extraction introduces further biases due to over- or under-segmentation of the image. Moreover, unless the grain distributions are fairly homogeneous between different locations, and images are collected in similar fashion, it is difficult to parametrize any such method in a transferable manner. In this study we present an image processing and machine learning procedure to automatically identify and measure grains from photographic images of gravel-bedded rivers. We apply the state-of-the-art of image segmentation techniques, making use of local cues such as brightness, color, and texture in a multi-scale approach. These cues are globalized using a graph partitioning method on the oriented contour signal. The resulting boundary probability signal is treated by a region-merging procedure that avoids the artifacts of standard segmentation, providing a flexible hierarchical structure which allows us to progressively retain the grains which give us the greatest level of confidence, based on a learned decisional model. Our parameter-free procedure characterizes grain size distributions both quantitatively and spatially, enabling the tool to deliver a spatial grid of grain size distributions at multiple scales, the finest of which depends upon image resolution and sediment characteristics. We test the procedure on a unique data set composed of a high-resolution photographic survey of the bed surface of a near-field-scale flume in which diverse square patches of particles were removed and sieved to obtain precise measurements. The results show that this procedure effectively and automatically recovers particle size distributions and the spatial pattern of sorting processes acting on the bed.

Bellugi, D.; Nelson, P. A.; Dietrich, W. E.

2010-12-01

392

Quantification of Geologic Lineaments by Manual and Machine Processing Techniques. [Landsat satellites - mapping/geological faults  

NASA Technical Reports Server (NTRS)

The effect of operator variability and subjectivity in lineament mapping and methods to minimize or eliminate these problems by use of several machine preprocessing methods was studied. Mapped lineaments of a test landmass were used and the results were compared statistically. The total number of fractures mapped by the operators and their average lengths varied considerably, although comparison of lineament directions revealed some consensus. A summary map (785 linears) produced by overlaying the maps generated by the four operators shows that only 0.4 percent were recognized by all four operators, 4.7 percent by three, 17.8 percent by two, and 77 percent by one operator. Similar results were obtained in comparing these results with another independent group. This large amount of variability suggests a need for the standardization of mapping techniques, which might be accomplished by a machine aided procedure. Two methods of machine aided mapping were tested, both simulating directional filters.

Podwysocki, M. H.; Moik, J. G.; Shoup, W. C.

1975-01-01

393

RDM: A Relational Database Machine.  

National Technical Information Service (NTIS)

There is felt a need in the data processing industry for computing machines which are designed specifically to handle information retrieval and storage. One concept of such a database machine, called a Relational Database Machine (RDM), is presented. The ...

H. S. Ames

1977-01-01

394

Applications of genetic algorithms in process planning: tool sequence selection for 2.5-axis pocket machining  

Microsoft Academic Search

Tool sequence selection is an important activity in process-planning for milling and has great bearing on the cost of machining.\\u000a Currently, it is accomplished manually without consideration of cost factors a priori. Typically, a large tool is selected\\u000a to quickly generate the rough shape and a smaller clearing tool is used to generate the net-shape. In this paper, we present\\u000a a

Zaryab Ahmad; Keyvan Rahmani; Roshan M. D’Souza

2010-01-01

395

Machine Vision  

NSDL National Science Digital Library

An overview of a generic image-based machine vision system is provided on this Web site (1). The tutorial describes the main components of such a system, how its accuracy is measured, and what scientific and industrial applications benefit from machine vision. A more technical perspective of machine vision technology is given in an online publication of the Automated Imaging Association (2). Monthly feature articles discuss breaking issues related to machine vision, and several technical papers can be downloaded, which are sorted into categories such as three dimensional imaging and nanotechnology. Researchers from the MIT's Artificial Intelligence Laboratory (3) are investigating how to enable a computer to interpret visual and audio signals from its human user. By using machine perception systems to track the user's gaze, for example, the computer could ascertain the focus of the user's attention, thereby facilitating interaction between the human and the computer. The project's homepage includes numerous research papers, as well as video demonstrations of some of its systems. Machine vision is also finding its way into vehicles. A March 2003 news article (4) highlights a field test in Michigan of a collision avoidance system that uses, among other things, machine vision to warn drivers that they are approaching a slower or stopped object too quickly. The 3D Computer Vision Group at Carnegie Mellon University (5) is involved in several projects, including three dimensional object recognition and humanoid robot vision. Many of the group's recent publications are available for download. NASA's Mars Exploration Rovers, the second of which was launched in July 2003, have vision systems that will let them safely navigate rough terrain. These systems are described in this conference paper (6), including specifics of the stereo vision algorithm and insights into future missions. A new implementation of machine vision comes from a former researcher from Cambridge University. His shape recognition system, which is detailed in this news article (7), is reportedly much more related to human visual processes than existing techniques. For additional developments related to this evolving technology, Machine Vision News (8) has information about worldwide research and new applications of machine vision systems.

Leske, Cavin.

396

Experimental Study of Re-impregnation Characteristics for Aged DC Machine and Effect of Application of Far Infrared Radiation to the process  

NASA Astrophysics Data System (ADS)

Recently hundreds of large dc machines manufactured for steel rolling mills at the high growing period are on the verge of replacement due to insulation deterioration of their armature windings after more than thirty years of service operation. Insulation technologies for aged machine are different from those for new machine, including varnish impregnation technologies. In this paper, experimental study of basic impregnation characteristics for aged dc machine to extend its life is described. Experimental study of application of far infrared radiation for the process is also presented.

Kiyokawa, Shin; Inoue, Haruo; Hirose, Haruo; Morita, Noboru

397

Consultant2: pre- and post-processing of Machine Learning applications  

Microsoft Academic Search

The knowledge acquisition bottleneck in the development of large knowledge based applications has not yet been resolved. One approach which has been advocated is the systematic use of Machine Learning (ML) techniques. However, ML technology poses difficulties to domain experts and knowledge engineers who are not familiar with it. This paper discusses Consultant-2, a system which makes a first step

Derek H. Sleeman; M. Rissakis; Susan Craw; Nicolas Graner; S. Sharma

1995-01-01

398

On Electro Discharge Machining of Inconel 718 with Hollow Tool  

NASA Astrophysics Data System (ADS)

Inconel 718 is a nickel-based alloy designed for high yield, tensile, and creep-rupture properties. This alloy has been widely used in jet engines and high-speed airframe parts in aeronautic application. In this study, electric discharge machining (EDM) process was used for machining commercially available Inconel 718. A copper electrode with 99.9% purity having tubular cross section was employed to machine holes of 20 mm height and 12 mm diameter on Inconel 718 workpieces. Experiments were planned using response surface methodology (RSM). Effects of five major process parameters—pulse current, duty factor, sensitivity control, gap control, and flushing pressure on the process responses—material removal rate (MRR) and surface roughness (SR) have been discussed. Mathematical models for MRR and SR have been developed using analysis of variance. Influences of process parameters on tool wear and tool geometry have been presented with the help of scanning electron microscope (SEM) micrographs. Analysis shows significant interaction effect of pulse current and duty factor on MRR yielding a wide range from 14.4 to 22.6 mm3/min, while pulse current remains the most contributing factor with approximate changes in the MRR and SR of 48 and 37%, respectively, corresponding to the extreme values considered. Interactions of duty factor and flushing pressure yield a minimum surface roughness of 6.2 ?m. The thickness of the sputtered layer and the crack length were found to be functions of pulse current. The hollow tool gets worn out on both the outer and the inner edges owing to spark erosion as well as abrasion due to flow of debris.

Rajesha, S.; Sharma, A. K.; Kumar, Pradeep

2012-06-01

399

Cylindrical Wire Electrical Discharge Machining of Metal Bond Diamond Wheels Part II: Wheel Wear Mechanism.  

National Technical Information Service (NTIS)

The use of stereo scanning Electron Microscopy (SEM) to investigate the wear mechanism of the wire EDM true metal bond diamond wheel for ceramic grinding is presented. On the grinding wheel, a wedge-shape removal part was machined to enable the examinatio...

B. K. Rhoney A. J. Shih R. O. Scattergood R. Ott S. B. McSpadden

2003-01-01

400

Mean Machines.  

ERIC Educational Resources Information Center

Suggests scales as alternative representations of numerical concepts and operations that can be used as arithmetic-mean machines, adding machines, multiplication machines, and geometric-mean machines. (ASK)

Flores, Alfinio

1998-01-01

401

Simple Machines  

NSDL National Science Digital Library

Online Simple Machines Assignment OBJECTIVES: Student\\'s will be able to name and describe all seven simple machines. Students will be able to identify simple machines that they use everyday. Example: Clock = Gear INSTRUCTIONS: 1. Click on the Simple Machines Glossary page and familiarize yourself with the seven simple machines. Simple Machines Glossary Page 2. Students are to click on ...

Oldroyd, Mr.

2007-09-26

402

Acoustic emission as a process monitor for diamond machining of metal optical components  

SciTech Connect

The results of a study of acoustic emission (AE) produced by diamond machining of 6061 Al mirrors are presented. Workpiece speed, depth of cut, and feed rate were systematically varied to assess their effects on AE production. AE signatures were very repeatable when cuts were made under identical conditions. Results are discussed in light of potential AE generation mechanisms which included material deformation, inclusion fracture, and friction. Detection of tool/workpiece contact by means of AE monitoring was demonstrated. 5 refs.

Whittaker, J.W.; Miller, A.C. Jr.

1991-07-01

403

A knowledge-based inspection process planning system for coordinate measuring machines  

Microsoft Academic Search

The coordinate measuring machine (CMM) is one of the most effective geometry inspection facilities used in manufacturing industry. To fully utilize its capabilities in a computer-integrated manufacturing (CIM) environment, we should integrate CMM with other systems and facilities. This paper presents the development of a knowledge-based inspection planner based on the fundamental principles of AI planning to integrate computer-aided design

P. Gu

1994-01-01

404

Organization of Parallel Query Processing in Multiprocessor Database Machines with Hierarchical Architecture  

Microsoft Academic Search

The development of database systems with hierarchical hardware architecture is currently a perspective trend in the field of parallel database machines. Hierarchical architectures have been suggested with the aim to combine advantages of shared-nothing architectures and shared-memory architectures with shared memory and disks. A commonly accepted way of construction of hierarchical systems is to combine shared-memory (shared-everything) clusters in a

Leonid B. Sokolinsky

2001-01-01

405

Acoustic emission as a process monitor for diamond machining of metal optical components  

NASA Astrophysics Data System (ADS)

The results of a study of acoustic emission (AE) produced by diamond machining of 6061 Al mirrors are presented. Workpiece speed, depth of cut, and feed rate were systematically varied to assess their effects on AE production. AE signatures were very repeatable when cuts were made under identical conditions. Results are discussed in light of potential AE generation mechanisms which included material deformation, inclusion fracture, and friction. Detection of tool/workpiece contact by means of AE monitoring was demonstrated.

Whittaker, J. W.; Miller, A. C., Jr.

1991-07-01

406

Femtosecond laser ablation properties of transparent materials: impact of the laser process parameters on the machining throughput  

NASA Astrophysics Data System (ADS)

High average power, high repetition rate femtosecond lasers with ?J pulse energies are increasingly used for bio-medical and material processing applications. With the introduction of femtosecond laser systems such as the SpiritTM platform developed by High Q Lasers and Spectra-Physics, micro-processing of solid targets with femtosecond laser pulses have obtained new perspectives for industrial applications [1]. The unique advantage of material processing with subpicosecond lasers is efficient, fast and localized energy deposition, which leads to high ablation efficiency and accuracy in nearly all kinds of solid materials. The study on the impact of the laser processing parameters on the removal rate for transparent substrate using femtosecond laser pulses will be presented. In particular, examples of micro-processing of poly-L-lactic acid (PLLA) - bio-degradable polyester and XensationTM glass (Schott) machined with SpiritTM ultrafast laser will be shown.

Matylitsky, V. V.; Hendricks, F.; Aus der Au, J.

2013-03-01

407

Improvement of form accuracy in hybrid machining of microstructures  

Microsoft Academic Search

Micromachining is gaining popularity due to recent advancements in Micro Electro Mechanical Systems. Using conventional micromachining,\\u000a it is relatively difficult to produce moving components in the order of microns. In this study, an attempt is made to fabricate\\u000a microstructures using a combination of turning and electrodischarge machining (EDM). Several sets of experiments have been\\u000a performed to study the characteristics of

H. S. Lim; A. Senthil Kumar; M. Rahman

2002-01-01

408

Statistical Process Control (SPC) for Coordinate Measurement Machines. Using SPC and Monitoring of Standard Artifacts to Determine and Control Measurement Uncertainty in a Controlled Environment.  

National Technical Information Service (NTIS)

The application of process capability analysis, using designed experiments, and gage capability studies as they apply to coordinate measurement machine (CMM) uncertainty analysis and control will be demonstrated. The use of control standards in designed e...

R. N. Escher

2002-01-01

409

Bending strength analysis of micro WC-shaft manufactured by micro electro-discharge machining  

Microsoft Academic Search

Micro electro-discharge machining (micro-EDM) is a critical technology to fabricate high aspect ratio 3D micro-components.\\u000a However, the surfaces of micro-components manufactured by micro-EDM will exhibit micro-cracks to produce notch effects, and\\u000a lead to stress concentrate and reduction of fatigue strength. This paper performs micro-bending tests to investigate the influence\\u000a of various roughness and size on the bending fracture strength of

Biing Hwa Yan; Sheng Ho Huang; Fuang Yuan Huang

2006-01-01

410

Progress Toward the Next Generation of Hg EDM Experiment  

NASA Astrophysics Data System (ADS)

At present the best limit on the EDM of a diamagnetic atom comes from our experiment(J.P. Jacobs, W.M. Klipstein, S.K. Lamoreaux, B. R. Heckel, and E.N. Fortson, Phys. Rev. A 52), 3521 (1995). in ^199Hg (d^199Hg<8.7 × 10-28e cm). The sensitivity of the experiment was limited by shot noise. We will discuss several developments which should allow us to improve the sensitivity by one or two orders of magnitude. We have replaced the resonance lamp with a UV laser for optical pumping at 254 nm. By quadrupling the output of a high power diode laser at 1016 nm we produced over 100?W of UV. The laser will allow us to increase the detection efficiency and the optical pumping rate, as well as the density of Hg in the cells. We are also studying the mechanism of spin relaxation of ^199Hg atoms on silane and paraffin surfaces in an effort to determine the limiting factor for the spin lifetime. Past experience indicates that significant improvement of the lifetime is possible.

Romalis, M. V.; Heckel, B. R.; Fortson, E. N.; Jacobs, J. P.

1998-05-01

411

A discrepancy within primate spatial vision and its bearing on the definition of edge detection processes in machine vision  

NASA Technical Reports Server (NTRS)

The visual perception of form information is considered to be based on the functioning of simple and complex neurons in the primate striate cortex. However, a review of the physiological data on these brain cells cannot be harmonized with either the perceptual spatial frequency performance of primates or the performance which is necessary for form perception in humans. This discrepancy together with recent interest in cortical-like and perceptual-like processing in image coding and machine vision prompted a series of image processing experiments intended to provide some definition of the selection of image operators. The experiments were aimed at determining operators which could be used to detect edges in a computational manner consistent with the visual perception of structure in images. Fundamental issues were the selection of size (peak spatial frequency) and circular versus oriented operators (or some combination). In a previous study, circular difference-of-Gaussian (DOG) operators, with peak spatial frequency responses at about 11 and 33 cyc/deg were found to capture the primary structural information in images. Here larger scale circular DOG operators were explored and led to severe loss of image structure and introduced spatial dislocations (due to blur) in structure which is not consistent with visual perception. Orientation sensitive operators (akin to one class of simple cortical neurons) introduced ambiguities of edge extent regardless of the scale of the operator. For machine vision schemes which are functionally similar to natural vision form perception, two circularly symmetric very high spatial frequency channels appear to be necessary and sufficient for a wide range of natural images. Such a machine vision scheme is most similar to the physiological performance of the primate lateral geniculate nucleus rather than the striate cortex.

Jobson, Daniel J.

1990-01-01

412

Electrochemical machining process for forming surface roughness elements on a gas turbine shroud  

DOEpatents

The back side recessed cooling surface of a shroud defining in part the hot gas path of a turbine is electrochemically machined to provide surface roughness elements and spaces therebetween to increase the heat transfer coefficient. To accomplish this, an electrode with insulating dielectric portions and non-insulating portions is disposed in opposition to the cooling surface. By passing an electrolyte between the cooling surface and electrode and applying an electrical current between the electrode and a shroud, roughness elements and spaces therebetween are formed in the cooling surface in opposition to the insulating and non-insulating portions of the electrode, hence increasing the surface area and heat transfer coefficient of the shroud.

Lee, Ching-Pang (Cincinnati, OH); Johnson, Robert Alan (Simpsonville, SC); Wei, Bin (Mechanicville, NY); Wang, Hsin-Pang (Rexford, NY)

2002-01-01

413

Introspective Machine.  

National Technical Information Service (NTIS)

An introspective machine, capable of passing judgment on its own deductive performances, is modelled and analyzed. First, the class of ideal machines which is provided with unlimited resources is studied. Since ideal introspective machines are usually unf...

G. A. W. Vreeswijk

1989-01-01

414

Non-traditional machining techniques  

SciTech Connect

During the course of machining targets for various experiments it sometimes becomes necessary to adapt fixtures or machines, which are designed for one function, to another function. When adapting a machine or fixture is not adequate, it may be necessary to acquire a machine specifically designed to produce the component required. In addition to the above scenarios, the features of a component may dictate that multi-step machining processes are necessary to produce the component. This paper discusses the machining of four components where adaptation, specialized machine design, or multi-step processes were necessary to produce the components.

Day, Robert D [Los Alamos National Laboratory; Fierro, Frank [Los Alamos National Laboratory; Garcia, Felix P [Los Alamos National Laboratory; Hatch, Douglass J [Los Alamos National Laboratory; Randolph, Randall B [Los Alamos National Laboratory; Reardon, Patrick T [Los Alamos National Laboratory; Rivera, Gerald [Los Alamos National Laboratory

2008-01-01

415

Meso-Machining Capabilities.  

National Technical Information Service (NTIS)

Meso-scale manufacturing processes are bridging the gap between silicon-based MEMS processes and conventional miniature machining. These processes can fabricate two and three-dimensional parts having micron size features in traditional materials such as s...

Benavides Adams Yang

2001-01-01

416

Machining: An Introduction  

NSDL National Science Digital Library

Basic machining processes are introduced on this site that is devoted to engineering fundamentals. Descriptions and illustrations of drilling, turning, grinding, and other common processes are provided for people with little to no prior machining knowledge. A waterjet is a non-traditional machining technology that uses high pressure streams of water with abrasive additives rather than solid cutting instruments to slice through metal and other materials.

2008-04-23

417

Annual Symposium on Machine Processing of Remotely Sensed Data, 4th, Purdue University, West Lafayette, Ind., June 21-23, 1977, Proceedings  

NASA Technical Reports Server (NTRS)

Papers are presented on a variety of techniques for the machine processing of remotely sensed data. Consideration is given to preprocessing methods such as the correction of Landsat data for the effects of haze, sun angle, and reflectance and to the maximum likelihood estimation of signature transformation algorithm. Several applications of machine processing to agriculture are identified. Various types of processing systems are discussed such as ground-data processing/support systems for sensor systems and the transfer of remotely sensed data to operational systems. The application of machine processing to hydrology, geology, and land-use mapping is outlined. Data analysis is considered with reference to several types of classification methods and systems.

Morrison, D. B. (editor); Scherer, D. J.

1977-01-01

418

Economic Decision Making Model for Geothermal Sludge Disposal alternatives (EDM-GSD): Version 1. 0  

SciTech Connect

The Economic Decision Making Model for Geothermal Sludge Disposal Alternatives-Version 1.0'' (EDM-GSD 1.0) is a microcomputer-based dynamic model developed to assist in determining the benefits and costs of various geothermal solid waste treatment procedures. It is intended for use by geothermal managers in dealing with geothermal waste and treatment process issues as a means to assist in overcoming the technical and economic barriers to expanded geothermal energy utilization. The model is based on a 50MW flash plant. However, it is designed to provide the user with sufficient flexibility when inputing data to analyze all types of geothermal plants. Default values for economic and technical parameters can be overridden by the user through the input of specific data. In addition, data can be changed for any year of an analysis to account for desired changes in input parameters such as costs and distance to disposal sites. The results of the model will allow the user to: Determine current geothermal plant disposal costs; Evaluate the cost-effectiveness of alternative treatment techniques; and Evaluate the economic effects of changes in disposal regulations.

Not Available

1987-09-01

419

Effect of single and multi-channel electrodes application on EDM fast hole drilling performance  

Microsoft Academic Search

This paper presents a comparative experimental investigation of electrical discharge machining fast hole drilling of aerospace\\u000a alloys, namely Inconel 718 and Ti–6Al–4V. A series of experiments was carried out using electrical discharge machining process\\u000a in order to explore the influence of electrode type and material, i.e., single and multi-channel tubular electrodes made of\\u000a brass and copper materials. The comparisons were

Oguzhan Yilmaz; M. Ali Okka

2010-01-01

420

Mechanical strength improvement of electrical discharge machined cemented carbides through PVD (TiN, TiAlN) coatings  

Microsoft Academic Search

Electrical discharge machining (EDM) is an alternative shaping route for manufacturing complex component shapes of hard and brittle materials as WC–Co cemented carbides (hardmetals). However, it results in a heat-affected surface layer with poor surface integrity that often leads to mechanical degradation of these materials. This work focuses on assessing the feasibility of physical vapor deposition (PVD) of hard coatings

B. Casas; A. Lousa; J. Calderón; M. Anglada; J. Esteve; L. Llanes

2004-01-01

421

Machine processing of remotely sensed data; Proceedings of the Conference, Purdue University, West Lafayette, Ind., October 16-18, 1973  

NASA Technical Reports Server (NTRS)

Topics discussed include the management and processing of earth resources information, special-purpose processors for the machine processing of remotely sensed data, digital image registration by a mathematical programming technique, the use of remote-sensor data in land classification (in particular, the use of ERTS-1 multispectral scanning data), the use of remote-sensor data in geometrical transformations and mapping, earth resource measurement with the aid of ERTS-1 multispectral scanning data, the use of remote-sensor data in the classification of turbidity levels in coastal zones and in the identification of ecological anomalies, the problem of feature selection and the classification of objects in multispectral images, the estimation of proportions of certain categories of objects, and a number of special systems and techniques. Individual items are announced in this issue.

1973-01-01

422

The temperature of a plasma used in electrical discharge machining  

NASA Astrophysics Data System (ADS)

The temperature in an electrical discharge machining (EDM) plasma was determined from measurements of relative intensities of the 411.85 and 413.29 nm Fe I spectral lines. The time-dependence of the plasma temperature was measured for individual electrical machining pulses. Under our experimental conditions (electrodes of C6(+) and M1E(-), cosmetic paraffin as the dielectric liquid) the measured plasma temperature ranged from 8000 to 10 000 K for different current pulses. We observed higher temperature values during the initial phase of the discharge. Temporal characteristics of discharge electric parameters, light emission and the plasma temperature are presented.

Albinski, Kazimierz; Musiol, Karol; Miernikiewicz, Adam; Labuz, Stefan; Malota, Marek

1996-11-01

423

Current breathomics-a review on data pre-processing techniques and machine learning in metabolomics breath analysis.  

PubMed

We define breathomics as the metabolomics study of exhaled air. It is a strongly emerging metabolomics research field that mainly focuses on health-related volatile organic compounds (VOCs). Since the amount of these compounds varies with health status, breathomics holds great promise to deliver non-invasive diagnostic tools. Thus, the main aim of breathomics is to find patterns of VOCs related to abnormal (for instance inflammatory) metabolic processes occurring in the human body. Recently, analytical methods for measuring VOCs in exhaled air with high resolution and high throughput have been extensively developed. Yet, the application of machine learning methods for fingerprinting VOC profiles in the breathomics is still in its infancy. Therefore, in this paper, we describe the current state of the art in data pre-processing and multivariate analysis of breathomics data. We start with the detailed pre-processing pipelines for breathomics data obtained from gas-chromatography mass spectrometry and an ion-mobility spectrometer coupled to multi-capillary columns. The outcome of data pre-processing is a matrix containing the relative abundances of a set of VOCs for a group of patients under different conditions (e.g. disease stage, treatment). Independently of the utilized analytical method, the most important question, 'which VOCs are discriminatory?', remains the same. Answers can be given by several modern machine learning techniques (multivariate statistics) and, therefore, are the focus of this paper. We demonstrate the advantages as well the drawbacks of such techniques. We aim to help the community to understand how to profit from a particular method. In parallel, we hope to make the community aware of the existing data fusion methods, as yet unresearched in breathomics. PMID:24713999

Smolinska, A; Hauschild, A-Ch; Fijten, R R R; Dallinga, J W; Baumbach, J; van Schooten, F J

2014-06-01

424

Machine learning and genetic algorithms in pharmaceutical development and manufacturing processes  

Microsoft Academic Search

We develop an adaptive Automated Intelligent Manufacturing System (AIMS) for Case 1:to a well-understood-pharmaceutical-process to demonstrate our methodology, Case 2:with clustering, to a not-well-controlled or understood-process for seemingly identical experiments yielding disparate results, Case 3:to scale-up a process from development to manufacturing, and Case 4:to deploy AIMS adaptively, to modify the process model and reoptimize the system contemporaneously, when predictive

Hoi-Ming Chi; Herbert Moskowitz; Okan K. Ersoy; Kemal Altinkemer; Peter F. Gavin; Bret E. Huff; Bernard A. Olsen

2009-01-01

425

XCUT: A rule-based expert system for the automated process planning of machined parts  

Microsoft Academic Search

Automated process planning is becoming a popular research and development topic in engineering and applied artificial intelligence. It is generally defined as the automatic planning of the manufacturing procedures for producing a part from a CAD based product definition. An automated process planning system, XCUT, is currently being developed using rule-based expert system techniques. XCUT will generate process plans for

S. L. Brooks; K. E. Hummel; M. L. Wolf

1987-01-01

426

Mathematical modelling of color mixing process and PLC control implementation by using human machine interface  

Microsoft Academic Search

The mixing process is a multivariable and intrinsically non-linear plant. Mathematical modelling of the mixing color process has been taken into consideration in order to design an adequate control (PI controllers) to assure zero steady state, fast control and disturbance rejection. The comparisons of the nonlinear mathematical model and linear one have been done. The control of the process has

Laurentiu Schiop; Marian Gaiceanu

2010-01-01

427

Machine Shop Grinding Machines.  

ERIC Educational Resources Information Center

This curriculum manual is one in a series of machine shop curriculum manuals intended for use in full-time secondary and postsecondary classes, as well as part-time adult classes. The curriculum can also be adapted to open-entry, open-exit programs. Its purpose is to equip students with basic knowledge and skills that will enable them to enter the…

Dunn, James

428

Graphical processing unit-based machine vision system for simultaneous measurement of shrinkage and soil release in fabrics  

NASA Astrophysics Data System (ADS)

We present a machine vision system for simultaneous and objective evaluation of two important functional attributes of a fabric, namely, soil release and shrinkage. Soil release corresponds to the efficacy of the fabric in releasing stains after laundering and shrinkage essentially quantifies the dimensional changes in the fabric postlaundering. Within the framework of the proposed machine vision scheme, the samples are prepared using a prescribed procedure and subsequently digitized using a commercially available off-the-shelf scanner. Shrinkage measurements in the lengthwise and widthwise directions are obtained by detecting and measuring the distance between two pairs of appropriately placed markers. In addition, these shrinkage markers help in producing estimates of the location of the center of the stain on the fabric image. Using this information, a customized adaptive statistical snake is initialized, which evolves based on region statistics to segment the stain. Once the stain is localized, appropriate measurements can be extracted from the stain and the background image that can help in objectively quantifying stain release. In addition, the statistical snakes algorithm has been parallelized on a graphical processing unit, which allows for rapid evolution of multiple snakes. This, in turn, translates to the fact that multiple stains can be detected and segmented in a computationally efficient fashion. Finally, the aforementioned scheme is validated on a sizeable set of fabric images and the promising nature of the results help in establishing the efficacy of the proposed approach.

Kamalakannan, Sridharan; Gururajan, Arunkumar; Hill, Matthew; Shahriar, Muneem; Sari-Sarraf, Hamed; Hequet, Eric F.

2010-04-01

429

Vacuum Electrical Breakdown Characteristics of Oxygen-free Copper Electrodes Processed by Precision Machining in Clean Space  

NASA Astrophysics Data System (ADS)

The vacuum electrical breakdown characteristics of oxygen-free copper electrodes, which were processed by precision diamond turning machining in a clean room and were heat-treated in hydrogen after that machining, were investigated by applying impulse voltage. These electrodes were carried in mobile vacuum chamber in order to keep them clean. The surface conditions were analyzed by the X-ray Photoelectron Spectroscopy (XPS) before and after the ion-beam sputtering and after the 500 times repetitive breakdowns. These experiments can be performed in in-situ experimental apparatus that are maintained in ultra-high vacuum (10-7 to 10-8Pa). As a result, these electrodes showed higher breakdown fields at the first breakdown relative to values obtained in the past studies. In addition, their conditioning achieved with less number of breakdowns. According to the XPS spectra, it was confirmed that organic contaminants were reduced by heat treatment in hydrogen and ion beam sputtering. These shows that heat treatment in hydrogen is effective in reducing contaminants on the electrode surface and improving the breakdown characteristics.

Yamamoto, Takashi; Otsuka, Takahiro; Yamano, Yasushi; Kobayashi, Shinichi; Higo, Toshiyasu; Toge, Nobukazu; Takata, Koji; Higashi, Yasuo; Saito, Yoshio; Hitomi, Nobuteru

430

The nEDM experiment at the Paul Scherrer Institute, Switzerland  

NASA Astrophysics Data System (ADS)

A permanent electric dipole moment of the neutron would be a sign of combined charge-conjugation and parity (CP) violation. The prediction of the Standard Model (SM) of particle physics for the neutron EDM is about 10-31 e cm and at the same time CP violation in the SM is insufficient in order to explain the observed baryon asymmetry of the universe (BAU). Several extensions of the SM aiming at explaining the observed BAU also predict values for the neutron EDM up to just below the current best experimental limit of dn <2.9×10-26e cm (90%C.L.) [1]. Our collaboration aims at improving the experimental sensitivity to the nEDM by two orders of magnitude which will probe a large part of the parameter space for these models.

Zenner, Johannes; nEDM Collaboration

2013-10-01

431

[Proceedings of the] International Conference on Educational Data Mining (EDM) (3rd, Pittsburgh, PA, July 11-13, 2010)  

ERIC Educational Resources Information Center

The Third International Conference on Data Mining (EDM 2010) was held in Pittsburgh, PA, USA. It follows the second conference at the University of Cordoba, Spain, on July 1-3, 2009 and the first edition of the conference held in Montreal in 2008, and a series of workshops within the AAAI, AIED, EC-TEL, ICALT, ITS, and UM conferences. EDM 2011…

Baker, Ryan S. J. d., Ed.; Merceron, Agathe, Ed.; Pavlik, Philip I., Jr., Ed.

2010-01-01

432

Proceedings of the International Conference on Educational Data Mining (EDM) (5th, Chania, Greece, June 19-21, 2012)  

ERIC Educational Resources Information Center

The 5th International Conference on Educational Data Mining (EDM 2012) is held in picturesque Chania on the beautiful Crete island in Greece, under the auspices of the International Educational Data Mining Society (IEDMS). The EDM 2012 conference is a leading international forum for high quality research that mines large data sets of educational…

International Educational Data Mining Society, 2012

2012-01-01

433

The Monitoring of Machines Surveillance des Machines.  

National Technical Information Service (NTIS)

The application of classical vibration analysis to the surveillance of the mechanical condition of machines is described. Automated procedures handled by specialized computers, using advanced signal processing techniques, are sought. Vibration measurement...

M. Gaillochet

1980-01-01

434

Using state machines to model the Ion Torrent sequencing process and to improve read error rates  

PubMed Central

Motivation: The importance of fast and affordable DNA sequencing methods for current day life sciences, medicine and biotechnology is hard to overstate. A major player is Ion Torrent, a pyrosequencing-like technology which produces flowgrams – sequences of incorporation values – which are converted into nucleotide sequences by a base-calling algorithm. Because of its exploitation of ubiquitous semiconductor technology and innovation in chemistry, Ion Torrent has been gaining popularity since its debut in 2011. Despite the advantages, however, Ion Torrent read accuracy remains a significant concern. Results: We present FlowgramFixer, a new algorithm for converting flowgrams into reads. Our key observation is that the incorporation signals of neighboring flows, even after normalization and phase correction, carry considerable mutual information and are important in making the correct base-call. We therefore propose that base-calling of flowgrams should be done on a read-wide level, rather than one flow at a time. We show that this can be done in linear-time by combining a state machine with a Viterbi algorithm to find the nucleotide sequence that maximizes the likelihood of the observed flowgram. FlowgramFixer is applicable to any flowgram-based sequencing platform. We demonstrate FlowgramFixer’s superior performance on Ion Torrent Escherichia coli data, with a 4.8% improvement in the number of high-quality mapped reads and a 7.1% improvement in the number of uniquely mappable reads. Availability: Binaries and source code of FlowgramFixer are freely available at: http://www.cs.tau.ac.il/~davidgo5/flowgramfixer.html. Contact: davidgo5@post.tau.ac.il

Golan, David; Medvedev, Paul

2013-01-01

435

Preliminary design and manufacturing feasibility study for a machined Zircaloy triangular pitch fuel rod support system (grids) (AWBA development program)  

SciTech Connect

General design features and manufacturing operations for a high precision machined Zircaloy fuel rod support grid intended for use in advanced light water prebreeder or breeder reactor designs are described. The grid system consists of a Zircaloy main body with fuel rod and guide tube cells machined using wire EDM, a separate AM-350 stainless steel insert spring which fits into a full length T-slot in each fuel rod cell, and a thin (0.025'' or 0.040'' thick) wire EDM machined Zircaloy coverplate laser welded to each side of the grid body to retain the insert springs. The fuel rods are placed in a triangular pitch array with a tight rod-to-rod spacing of 0.063 inch nominal. Two dimples are positioned at the mid-thickness of the grid (single level) with a 90/sup 0/ included angle. Data is provided on the effectiveness of the manufacturing operations chosen for grid machining and assembly.

Horwood, W A [ed.] [ed.

1981-07-01

436

Analysis of the rheological model of the process of chip formation with metal machining  

Microsoft Academic Search

The present paper discusses mathematical modelling with regard to deformation processes resulting from chip forming and removal when cutting heavilyprocessed materials in a condition of non-homogeneous stress state, which can evoke undesirable self-excited oscillation. By describing the chip forming and removal process a synthesized rheological model was used.

V. Maksarov; J. Olt

437

Support vector machines for recognizing shifts in correlated and other manufacturing processes  

Microsoft Academic Search

Traditional statistical process control (SPC) techniques of control charting are not applicable in many process industries where the data from the facilities are often autocorrelated. This is often true in piece-part manufacturing industries that are highly automated and integrated. Several attempts have been made in the literature to extend traditional SPC techniques to deal with autocorrelated parameters. However, these extensions

RATNA BABU

438

Measurement of an off-axis parabolic mirror using coordinates measurement machine and swing arm profilometer during the grinding process  

NASA Astrophysics Data System (ADS)

We present the measurement methods for off-axis parabolic mirrors using Coordinates Measurement Machine and Swing Arm Profilometer during the grinding process. An off-axis parabolic mirror with 1200mm in parent focal length, 360mm in off-axis displacement and 410mm in diameter is measured using the methods introduced in this paper. The convergence curves of the surface error are reported, which is reduced from 204.7?m in PV, 55.3?m in rms to 1.1?m in PV, 0.3?m in rms after 39 iterations of grinding. Besides, the measurement methods are able to control the parent focal length and off-axis displacement to less than 0.1mm tolerance. An interferometric result is presented, which validates the measurement methods.

Jing, Hongwei; Lin, Changqing; Fan, Bin; Kuang, Long; Wu, Shibin; Wu, Fan; Fan, Tianquan

439

Computer-Aided TRIZ Ideality and Level of Invention Estimation Using Natural Language Processing and Machine Learning  

NASA Astrophysics Data System (ADS)

Patent textual descriptions provide a wealth of information that can be used to understand the underlying design approaches that result in the generation of novel and innovative technology. This article will discuss a new approach for estimating Degree of Ideality and Level of Invention metrics from the theory of inventive problem solving (TRIZ) using patent textual information. Patent text includes information that can be used to model both the functions performed by a design and the associated costs and problems that affect a design’s value. The motivation of this research is to use patent data with calculation of TRIZ metrics to help designers understand which combinations of system components and functions result in creative and innovative design solutions. This article will discuss in detail methods to estimate these TRIZ metrics using natural language processing and machine learning with the use of neural networks.

Adams, Christopher; Tate, Derrick

440

Current source LCC resonant converter for an EDM power supply  

Microsoft Academic Search

In this paper, the design of a low size power supply prototype for electrical discharge machining is presented. The system is a DC to DC LCC resonant converter whose switching frequency is tuned at the natural resonant frequency where the converter tends to act as a current source. In this way, two effects are achieved: (1) the necessary over-voltage, first

Rosario Casanueva; Luis A. Chiquito; Francisco J. Azcondo; Salvador Bracho

2001-01-01

441

Machine Vision for High Precision Volume Measurement Applied to Levitated Containerless Materials Processing  

NASA Technical Reports Server (NTRS)

By combining the best practices in optical dilatometry with new numerical methods, a high-speed and high precision technique has been developed to measure volume of levitated, containerlessly processed samples with sub- pixel resolution. Containerless processing provides the ability to study highly reactive materials without the possibility of contamination affecting thermo-physical properties. Levitation is a common technique used to isolate a sample as it is being processed. Noncontact optical measurement of thermo-ophysical properties is very important as traditional measuring methods cannot be used. Modern, digitally recorded images require advanced numerical routines to recover the sub-pixel locations of sample edges and, in turn produce high precision measurements.

Bradshaw, R. C.; Schmidt, D. P.; Rogers, J. R.; Kelton, K. F.; Hyers, R. W.

2005-01-01

442

Application of Machine Learning and Expert Systems to Statistical Process Control (SPC) Chart Interpretation.  

National Technical Information Service (NTIS)

Statistical Process Control (SPC) charts are one of several tools used in quality control. Other tools include flow charts, histograms, cause and effect diagrams, check sheets, Pareto diagrams, graphs, and scatter diagrams. A control chart is simply a gra...

M. Shewhart

1991-01-01

443

Straightening-stretching machine  

SciTech Connect

A straightening-stretching machine has been designed at the All Union Design and Research Institute for Chemical Engineering. It straightens metal strips in the cold state by stretching beyond their limit with a maximum extension deformation of 3%. A sketch indicates stand, drive for untwisting strip, power cylinder, slide block, and front clamping head, among other aspects of the machine. The technical characteristics are specified and the process is explained. The economy affected on introducing the straightening-stretching machine is indicated.

Deryabin, G.N.; Kuz'min, G.G.

1983-07-01

444

Real-time wireless monitoring of workpiece material and debris characteristics in micro-electro-discharge machining  

Microsoft Academic Search

Wireless signals are generated with each discharge in micro-electro-discharge machining (muEDM), providing an opportunity to directly monitor discharge quality. Unlike traditional methods of monitoring progress in machining, which rely on electrical characteristics at the discharge supply terminals, this method is less affected by parasitics. The depth location of a metal-metal interface can be distinguished in the wireless signal. This is

Mark T. Richardson; Yogesh B. Gianchandani

2008-01-01

445

Bioinspired material based on femtosecond laser machining of cast sheet micromolding as a pattern transfer process.  

PubMed

We present herein a simple, fast, and easy-to-use process to replicate poly(methyl methacrylate) (PMMA) plates generating surface effects. First, a femtosecond laser has been used to fabricate, with sufficient accuracy, a periodic pattern on a glass plate at the microscale. This glass plate, used as a master, can be structured on a large distance with a good control of its roughness. Then, the polymer plates were obtained by bulk polymerization without any solvents with a good replication from the cast sheet process, which has been industrially performed for years. Thus, the modification of this process, environmentally friendly, lets us foresee new applications for commodity polymers by introducing visual iridescent properties and hydrophobicity exaltation. PMID:21309506

Sarrat, B; Pécheyran, C; Bourrigaud, S; Billon, L

2011-03-15

446

Using a design of experiment method to improve KDP crystal machining process  

NASA Astrophysics Data System (ADS)

Surface quality is an important issue for KDP crystals implemented in high power lasers. Single Point Diamond Turning is the only way to get the required transmitted wavefront and damage threshold, especially in the UV band of the laser Megajoule. The aim of the process development was to reach an rms roughness lower than 3 nm using a vertical fly-cutter, an appropriate cleaning equipment and an interferometric microscope for measurements. A Taguchi Design of Experiment method has been used to optimize the fly-cutting process parameters on 100 X 100 mm2 KDP crystals.

Lahaye, Philippe; Chomont, Christian; Dumont, Pierre; Duchesne, Jacky; Chabassier, Genevieve

1999-09-01

447

Using a design of experiment method to improve KDP crystal machining process  

NASA Astrophysics Data System (ADS)

Surface quality is an important issue for KDP crystal implemented in high power lasers. Single Point Diamond Turning is the only way to get the required transmitted wavefront and damage threshold, specially in the UV band of the laser Megajoule. The aim of the process development was to reach an rms roughness lower than 3 nm using a vertical fly-cutter, an appropriate cleaning equipment and an interferometric microscope for measurements. A Taguchi Design of Experiment method has been sued to optimize the fly-cutting process parameters on 100 X 100 mm2 KDP crystals.

Lahaye, Philippe; Chomont, Christian; Dumont, Pierre; Duchesne, Jacky; Chabassier, Genevieve

1999-07-01

448

An analysis of metropolitan land-use by machine processing of earth resources technology satellite data  

NASA Technical Reports Server (NTRS)

A successful application of state-of-the-art remote sensing technology in classifying an urban area into its broad land use classes is reported. This research proves that numerous urban features are amenable to classification using ERTS multispectral data automatically processed by computer. Furthermore, such automatic data processing (ADP) techniques permit areal analysis on an unprecedented scale with a minimum expenditure of time. Also, classification results obtained using ADP procedures are consistent, comparable, and replicable. The results of classification are compared with the proposed U. S. G. S. land use classification system in order to determine the level of classification that is feasible to obtain through ERTS analysis of metropolitan areas.

Mausel, P. W.; Todd, W. J.; Baumgardner, M. F.

1976-01-01

449

Review of the investigation of mixture formation and combustion process using rapid compression machine and direct visualization system  

NASA Astrophysics Data System (ADS)

This paper reviews of some applications of optical visualization systems to compute the fuel-air mixing process during early stage of mixture formation in Diesel Combustion Engines. A number of studies have contributed to the understanding of fuel air mixing in DI diesel engine. This review has shown that the mixture formation process affects initial flame development. The review also found that injection pressure has a great effect on the mixture formation then the flame development and combustion characteristics. The method of the simulation of real phenomenon of diesel combustion with optical access rapid compression machine is also reviewed and experimental results are presented. The application of these methods to the investigation of diesel sprays highlights mechanisms which govern propagation and distribution of the formation of a combustible fuel-air mixture. A summary of the implementation of constant volume chamber and optical visualization system are shown in the accompanying tables and figures. The visualization of the formation process of diesel spray and its combustion in the diesel combustion chamber of diesel engine has been recognized as one of the best ways to understand the characteristics of the mixture formation.

Jaat, M.; Khalid, Amir; Manshoor, B.; Ramsy, Him

2013-12-01

450

Running BSD Kernels as User Processes by Partial Emulation and Rewriting of Machine Instructions  

Microsoft Academic Search

A user-level operating system (OS) can be im- plemented as a regular user process on top of an- other host operating system. Conventional user- level OSes, such as User Mode Linux, view the un- derlying host operating system as a specific hard- ware architecture. Therefore, the implementation of a user-level OS often requires porting of an ex- isting kernel to

Hideki Eiraku; Yasushi Shinjo

2003-01-01

451

Objective detection of the central auditory processing disorder:A new machine learning approach  

Microsoft Academic Search

The objective detection of binaural interaction is of diagnostic interest for the evaluation of the central auditory processing disorder (CAPD). The ?-wave of the binaural interaction component in auditory brainstem responses has been suggested as an objective measure of binaural interaction and has been shown to be of diagnostic value in the CAPD diagnosis. However, a reliable and automated detection

Daniel J. Strauss; Wolfgang Delb; Peter K. Plinkert

2004-01-01

452

Intelligent detection of DTMF tones using a hybrid signal processing technique with support vector machines  

Microsoft Academic Search

Efficient methods for DTMF signal detection are important for developing telecommunication equipment. This paper presents a hybrid signal processing and artificial intelligence based approach for the detection of Dual-tone Multifrequency (DTMF) tones under the influence of White Gaussian Noise (WGN) and frequency variation. Key innovations include the use of a Finite Impulse Response (FIR) bandpass filter for reduction of noise

J. Nagi; K. S. Yap; S. K. Tiong; S. K. Ahmed; F. Nagi

2008-01-01

453

New processing possibilities of materials by micro and nano precision laser machining for microelectronics applications  

NASA Astrophysics Data System (ADS)

The permanently development of microelectronics production by continuously increasing of devices densities meantime with corresponding decreasing of processing line till further submicronic range. The processing of huge diversity of materials as metals, polymers, ceramics, silicon, germanium, other materials III-Vs, glass, diamond, hard metal oxides, composites is need. On this paper will be presented our advanced studies and of experiments realized with very good results for a full range of those materials by micro and nanoprocessing for to realize the best accuracy, according with microelectronics technical requirements specified as below: 1. The microdrilling for microvias used for MCM's, MEMS and MOEMS application. 2. The high precision microcutting and scribing used for individual chips separation Isingulation on processed wafers of micro and optoelectronics applications 3. 2D I3D processing for microlens, microlens array and microalveoles fabrication 4. Microengraving of KOP (Potasium dihydrogen phosphate) crystal by laser microablation 5. Micro and nano cleaning of thin and ultrathin layers need for production of microelectronics devices production.

Ulieru, Dumitru; Apostol, Ileana

2005-06-01

454

Widening the adoption of workflows to include human and human-machine scientific processes  

NASA Astrophysics Data System (ADS)

Scientific workflows capture knowledge in the form of technical recipes to access and manipulate data that help scientists manage and reuse established expertise to conduct their work. Libraries of scientific workflows are being created in particular fields, e.g., Bioinformatics, where combined with cyber-infrastructure environments that provide on-demand access to data and tools, result in powerful workbenches for scientists of those communities. The focus in these particular fields, however, has been more on automating rather than documenting scientific processes. As a result, technical barriers have impeded a wider adoption of scientific workflows by scientific communities that do not rely as heavily on cyber-infrastructure and computing environments. Semantic Abstract Workflows (SAWs) are introduced to widen the applicability of workflows as a tool to document scientific recipes or processes. SAWs intend to capture a scientists’ perspective about the process of how she or he would collect, filter, curate, and manipulate data to create the artifacts that are relevant to her/his work. In contrast, scientific workflows describe the process from the point of view of how technical methods and tools are used to conduct the work. By focusing on a higher level of abstraction that is closer to a scientist’s understanding, SAWs effectively capture the controlled vocabularies that reflect a particular scientific community, as well as the types of datasets and methods used in a particular domain. From there on, SAWs provide the flexibility to adapt to different environments to carry out the recipes or processes. These environments range from manual fieldwork to highly technical cyber-infrastructure environments, i.e., such as those already supported by scientific workflows. Two cases, one from Environmental Science and another from Geophysics, are presented as illustrative examples.

Salayandia, L.; Pinheiro da Silva, P.; Gates, A. Q.

2010-12-01

455

Machining Data for Beryllium Metal.  

National Technical Information Service (NTIS)

The report contains evaluated machining information for beryllium which has been extracted from many sources. Machining data are tabulated and presented in chart form for the following processes: turning, milling, drilling, band sawing, grinding, boring, ...

J. F. Kahles R. F. Snider

1966-01-01

456

SQUID magnetometry for the cryoEDM experiment---Tests at LSBB  

Microsoft Academic Search

High precision magnetometry is an essential requirement of the cryoEDM experiment at the Institut Laue-Langevin, Grenoble. We have developed a SQUID system for this purpose, however tests done in Oxford have been limited by the noisy electromagnetic environment inside our laboratory, therefore we have tested a smaller version of our prototype system in the very low noise environment at LSBB,

S. Henry; H. Kraus; M. Malek; V. B. Mikhailik; G. Waysand

2008-01-01

457

Results from a Search for the Permanent Electric Dipole Moment (EDM) of ^199Hg  

NASA Astrophysics Data System (ADS)

Observation of a nonzero EDM would imply CP violation beyond the Standard Model. Additional sources of CP violation are expected to help explain the matter-antimatter asymmetry observed in our universe and naturally arise in extensions to the standard model such as supersymmetry. Our group has recently reported a new upper limit: |dHg| < 3.1x10-29 e-cm for the EDM of ^199Hg. The experiment compared the spin precession frequencies in four spin-polarized Hg vapor cells: two cells lie in parallel magnetic and anti-parallel electric fields, resulting in EDM-sensitive spin precession while the remaining two cells, at zero electric field, serve to cancel noise generated by magnetic field gradients and test for systematic errors. A frequency shift, linear in the applied electric field, due to the Stark mixing of atomic states has been identified and measured. A description of the EDM experiment and measurements that led to our recent result will be presented. )

Heckel, Blayne

2010-02-01

458

Multimodal interactive machine translation  

Microsoft Academic Search

Interactive machine translation (IMT) [1] is an alternative approach to machine translation, integrating human expertise into the automatic translation process. In this framework, a human iteratively interacts with a system until the output desired by the human is completely generated. Traditionally, interaction has been performed using a keyboard and a mouse. However, the use of touchscreens has been popularised recently.

Vicent Alabau; Daniel Ortiz-Martínez; Alberto Sanchis; Francisco Casacuberta

2010-01-01

459

Relational Algebra Machine GRACE  

Microsoft Academic Search

Most of the data base machines proposed so far which adopts a filter processor as their basic unit show poor performance for the heavy load operation such as join and projection etc., while they can process the light load operations such as selection and update for which a full scan of a file suffices. These machines which incorporates n processors

Masaru Kitsuregawa; Hidehiko Tanaka; Tohru Moto-oka

1982-01-01

460

PASM (partitionable SIMD/MIND machine) parallel-processing system: Hardware design and intelligent operating system concepts. Final report  

SciTech Connect

Many of today's scientific and industrial problems require enormous computing power. Since circuit switching speeds are reaching fundamental limits, avenues to speed up computations other than that using faster components are being explored. One such avenue is the use of parallelism. PASM is a dynamically reconfigurable SIMD/MIMD parallel processing system with up to 1,024 processing elements (PEs). It can be dynamically reconfigured to work as one or more SIMD (single instruction stream - multiple data stream) and/or MIMD (multiple instruction stream - multiple data stream) machines. A prototype with 30 MC68010 microprocessors, including 16 PEs in the computational engine, is being designed and constructed. The design of the prototype hardware is described, as well as the design tradeoffs that were made. Extending the current prototype by the addition of a Network Interface Unit (NIU) to each PE is proposed. Such an NIU significantly enhances interprocessor communication by offloading communication overhead from the PE's main CPU. One way to extend the prototype design to a system with 1,024 processors in the computational engine is presented. The powerful reconfiguration capabilities of PASM can be fully utilized only if all tradeoffs influencing reconfiguration are known.

Schwederski, T.

1986-07-01

461

Large-scale cell production of stem cells for clinical application using the automated cell processing machine  

PubMed Central

Background Cell-based regeneration therapies have great potential for application in new areas in clinical medicine, although some obstacles still remain to be overcome for a wide range of clinical applications. One major impediment is the difficulty in large-scale production of cells of interest with reproducibility. Current protocols of cell therapy require a time-consuming and laborious manual process. To solve this problem, we focused on the robotics of an automated and high-throughput cell culture system. Automated robotic cultivation of stem or progenitor cells in clinical trials has not been reported till date. The system AutoCulture® used in this study can automatically replace the culture medium, centrifuge cells, split cells, and take photographs for morphological assessment. We examined the feasibility of this system in a clinical setting. Results We observed similar characteristics by both the culture methods in terms of the growth rate, gene expression profile, cell surface profile by fluorescence-activated cell sorting, surface glycan profile, and genomic DNA stability. These results indicate that AutoCulture® is a feasible method for the cultivation of human cells for regenerative medicine. Conclusions An automated cell-processing machine will play important roles in cell therapy and have widespread use from application in multicenter trials to provision of off-the-shelf cell products.

2013-01-01

462

Kid Machine  

NSDL National Science Digital Library

This activity is on page 3 (continued on page 2) of the pdf, part of the Simple Machines Discovery Box. In this fun activity, learners "create" a complex machine by simulating the parts in action. Learners move their bodies and make sounds as if they are individual parts of a moving machine. Then learners discover what happens when part of a machine is broken and problem solve ways to fix it.

Omsi

2004-01-01

463

Electrostatic Machines  

NSDL National Science Digital Library

This website from Antonio Carlos M. De Queiroz, an associate professor at the Federal University of Rio de Janeiro, illustrates a number of different electrostatic machines. The site includes details and images of machines built by the professor as well as many other historical machines of this type. Some information is also available in Portugese.

De Queiroz, Antonio C.

2011-07-13

464

Simple Machines  

NSDL National Science Digital Library

This is an online activity about simple machines. Learners will try their hand at putting these amazing devices to work. They will use several simple machines to help "build" a tree house. This is an excellent activity to demonstrate how science - in particular, simple machines - are at work in our everyday lives.

Cosi

2000-01-01

465

An innovative method for coordinate measuring machine one-dimensional self-calibration with simplified experimental process  

NASA Astrophysics Data System (ADS)

In this paper, an innovative method for CMM (Coordinate Measuring Machine) self-calibration is proposed. In contrast to conventional CMM calibration that relies heavily on a high precision reference standard such as a laser interferometer, the proposed calibration method is based on a low-cost artefact which is fabricated with commercially available precision ball bearings. By optimizing the mathematical model and rearranging the data sampling positions, the experimental process and data analysis can be simplified. In mathematical expression, the samples can be minimized by eliminating the redundant equations among those configured by the experimental data array. The section lengths of the artefact are measured at arranged positions, with which an equation set can be configured to determine the measurement errors at the corresponding positions. With the proposed method, the equation set is short of one equation, which can be supplemented by either measuring the total length of the artefact with a higher-precision CMM or calibrating the single point error at the extreme position with a laser interferometer. In this paper, the latter is selected. With spline interpolation, the error compensati