Investigation of Wire Electrical Discharge Machining of Thin Cross-Sections and Compliant Mechanisms

2004 ◽  
Author(s):  
Scott F. Miller ◽  
Enhui Shi ◽  
Chen-C. Kao ◽  
Albert J. Shih ◽  
Jun Qu
Keyword(s):  
Cross Section ◽  
Process Parameters ◽  
Electrical Discharge ◽  
Compliant Mechanisms ◽  
Electrical Discharge Machining ◽  
Limiting Factor ◽  
Wire Electrical Discharge Machining ◽  
Wire Edm ◽  
Thin Sections ◽  
Edm Process

The wire electrical discharge machining (EDM) of cross-section with minimum thickness and compliant mechanisms are studied. Effects of EDM process parameters, particularly the spark cycle time and spark on-time on thin cross-section cutting of Nd-Fe-B magnetic material, carbon bipolar plate, and titanium are investigated. An envelope of feasible wire EDM process parameters is generated for Ti. The application of such envelope to select suitable EDM process parameters for micro feature generation is demonstrated. Scanning Electron Microscopy (SEM) analysis of EDM surface, subsurface, and debris are presented. SEM observations lead to a hypothesis based on the thermal and electrostatic stress induced fracture to explain the limiting factor for wire EDM cutting of thin-sections. Applications of the thin cross-section cutting for EDM compliant mechanisms are discussed.

Investigation of the Spark Cycle Effect on Material Removal Rate in Wire Electrical Discharge Machining

Manufacturing ◽  
2003 ◽  
Author(s):  
Scott F. Miller ◽  
Albert J. Shih
Keyword(s):  
Process Parameters ◽  
Material Removal Rate ◽  
Electrical Discharge ◽  
Material Removal ◽  
Electrical Discharge Machining ◽  
Removal Rate ◽  
Short Circuit ◽  
Wire Electrical Discharge Machining ◽  
Time Duration ◽  
Edm Process

The development of new, advanced engineering materials and the needs for precise and flexible prototype and low-volume production have made wire electrical discharge machining (EDM) an important manufacturing process to meet such demand. This research investigates the effect of spark on-time duration and spark on-time ratio, two important EDM process parameters, on the material removal rate (MRR) and surface integrity of four types of advanced material: porous metal foams, metal bond diamond grinding wheels, sintered Nd-Fe-B magnets, and carbon-carbon bipolar plates. An experimental procedure was developed. During the wire EDM, five types of constraints on the MRR due to short circuit, wire breakage, machine slide speed limit, and spark on-time upper and lower limits have been identified. An envelope of feasible EDM process parameters is created and compared across different work-materials. Applications of such process envelope to select process parameters for maximum MRR and for machining of micro features are presented.

Development of the Cylindrical Wire Electrical Discharge Machining Process, Part 1: Concept, Design, and Material Removal Rate

2002 ◽  
Vol 124 (3) ◽  
pp. 702-707 ◽  
Author(s):  
Jun Qu ◽  
Albert J. Shih ◽  
Ronald O. Scattergood
Keyword(s):  
Material Removal Rate ◽  
Electrical Discharge ◽  
Material Removal ◽  
Electrical Discharge Machining ◽  
Removal Rate ◽  
Free Form ◽  
Wire Electrical Discharge Machining ◽  
Wire Edm ◽  
Edm Process ◽  
Cylindrical Wire

Results of applying the wire Electrical Discharge Machining (EDM) process to generate precise cylindrical forms on hard, difficult-to-machine materials are presented. The design of a precise, flexible, and corrosion-resistant underwater rotary spindle is first introduced. A detailed spindle error analysis identifies the major sources of error at different frequency spectrum. The spindle has been added to a conventional two-axis wire EDM machine to enable the generation of free-form cylindrical geometries. The mathematical model for material removal rate of the free-form cylindrical wire EDM process is derived. Experiments were conducted to explore the maximum material removal rate for cylindrical and 2D wire EDM of carbide and brass work-materials. Compared to the conventional 2D wire EDM of the same work-material, higher maximum material removal rates may be achieved in the cylindrical wire EDM, possibly due to better debris flushing condition.

Microstructural Characterization of Thermal Damage on Silicon Wafers Sliced Using Wire-Electrical Discharge Machining

2018 ◽  
Vol 140 (9) ◽  
Author(s):  
Kamlesh Joshi ◽  
Upendra Bhandarkar ◽  
Indradev Samajdar ◽  
Suhas S. Joshi
Keyword(s):  
Raman Spectroscopy ◽  
Electrical Discharge ◽  
Thermal Damage ◽  
Electrical Discharge Machining ◽  
Wafer Surface ◽  
Wire Electrical Discharge Machining ◽  
Wire Edm ◽  
Material Loss ◽  
Pulse On Time

Slicing of Si wafers through abrasive processes generates various surface defects on wafers such as cracks and surface contaminations. Also, the processes cause a significant material loss during slicing and subsequent polishing. Recently, efforts are being made to slice very thin wafers, and at the same time understand the thermal and microstructural damage caused due to sparking during wire-electrical discharge machining (wire-EDM). Wire-EDM has shown potential for slicing ultra-thin Si wafers of thickness < 200 μm. This work, therefore, presents an extensive experimental work on characterization of the thermal damage due to sparking during wire-EDM on ultra-thin wafers. The experiments were performed using Response surface methodology (RSM)-based central composite design (CCD). The damage was mainly characterized by scanning electron microscope (SEM), transmission electron microscopy (TEM), and Raman spectroscopy. The average thickness of thermal damage on the wafers was observed to be ∼16 μm. The damage was highly influenced by exposure time of wafer surface with EDM plasma spark. Also, with an increase in diameter of plasma spark, the surface roughness was found to increase. TEM micrographs have confirmed the formation of amorphous Si along with a region of fine grained Si entrapped inside the amorphous matrix. However, there were no signs of other defects like microcracks, twin boundaries, or fracture on the surfaces. Micro-Raman spectroscopy revealed that in order to slice a wafer with minimum residual stresses and very low presence of amorphous phases, it should be sliced at the lowest value of pulse on-time and at the highest value of open voltage (OV).

Development of a Copper Heat Pipe with Axial Grooves Manufactured Using Wire Electrical Discharge Machining (Wire-EDM)

2015 ◽  
Vol 1120-1121 ◽  
pp. 1325-1329 ◽  
Author(s):  
Felipe B. Nishida ◽  
Larissa S. Marquardt ◽  
Valquíria Y.S. Borges ◽  
Paulo H.D. Santos ◽  
Thiago Antonini Alves
Keyword(s):  
Heat Pipe ◽  
Thermal Management ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Average Diameter ◽  
Working Fluid ◽  
Outer Diameter ◽  
Wire Electrical Discharge Machining ◽  
Wire Edm ◽  
Heat Loads

In this research, a heat pipe with grooves was experimentally analyzed for the application in thermal management of electronic packaging. The heat pipe was produced by a copper tube with an outer diameter of 9.45 mm, length of 205 mm, and capillary structure composed by axial grooves with average diameter of 220 μm. The grooves were manufactured using wire electrical discharge machining (wire-EDM). The working fluid used was de-ionized water. The condenser was cooled by air forced convection and the evaporator was heated using an electrical resistor. This heat pipe was tested horizontally to increasing heat loads varying from 5 to 15 W. The experimental results showed that the heat pipe worked successfully.

Surface Roughness Optimization of Wire Electrical Discharge Machining Using ABC Algorithm

2015 ◽  
Vol 766-767 ◽  
pp. 902-907
Author(s):  
Bibin K. Tharian ◽  
B. Kuriachen ◽  
Josephkunju Paul ◽  
Paul V. Elson
Keyword(s):  
Surface Roughness ◽  
Process Parameters ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Wire Electrical Discharge Machining ◽  
Wire Tension ◽  
Pulse On Time ◽  
Pulse Off Time ◽  
Off Time ◽  
Wire Feed

Wire electrical discharge machining is one of the important non-traditional machining processes for machining difficult to machine materials. It involves the removal of material by the discrete electric discharges produced between the inter electrode gap of continuously moving wire electrode and the work piece. The ability to produce intricate profiles on materials irrespective of the mechanical properties made this process to be widely used in industries. The present study investigates the relationship of various process parameters in WEDM of AISI 202 stainless steel with brass electrode.The experiments were planned according to Taguchi’s L18 orthogonal array and experimental models were developed. The important process parameters identified for the present study were pulse on time, peak current, pulse off time, wire feed, wire tension, dielectric flushing pressure, servo feed and gap voltage. The surface roughness of the machined surface was measured as the process performance measure. Analysis of variance test has also been carried out to check the adequacy of the developed models and to identify the level of significance of each process parameters. In addition to the developed models, ABC optimization has been performed to identify the optimum parameter combination for minimum surface roughness and the obtained optimal process parameters are peak current 11 A, pulse on time 100 μs, pulse off time 49 μs, wire feed 4 m/min, wire tension 10 N, flushing pressure 12 kg/cm2, servo feed 2100 mm/min and set gap voltage 30 V. Finally the results were verified with the experimental results and found that they are in good agreement.

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