Simultaneous micro-EDM and micro-ECM in low-resistivity deionized water

Abstract Micro-EDM and micro-ECM are two suitable machining processes for micro- and nano-fabrication. Each process alone has some undesirable effects which confine its capability. By appropriate combination of these two processes, the adverse effects can be significantly mitigated. However, micro-EDM operates in non-conductive dielectric fluid whereas micro-ECM employs conductive electrolyte. Because of two rather divergent requirements, micro-EDM and micro-ECM are usually used sequentially. By using low-resistivity deionized water, which exhibits both characteristics of a slightly conductive fluid and a dielectric fluid, this study aims to combine micro-EDM and micro-ECM in a unique hybrid machining process to achieve improved performance in both surface finish and machining accuracy. Through the analysis of material removal phenomenon in micro-EDM using low-resistivity deionized water, it is found that there is a conversion of material removal mechanism from mere micro-EDM to hybrid micro-EDM/ECM when low feedrate is applied. Arising from this observation, a novel hybrid machining process, named as simultaneous micro-EDM and micro-ECM (SEDCM), has been developed. Three key factors of SEDCM, namely low-resistivity deionized water, low feedrate and short voltage pulses, are identified.

[1]  Chong Nam Chu,et al.  Micro electrical discharge drilling of tungsten carbide using deionized water , 2009 .

[2]  Kamlakar P Rajurkar,et al.  Selected problems of micro-electrochemical machining , 2004 .

[3]  Takahisa Masuzawa,et al.  State of the Art of Micromachining , 2000 .

[4]  Kamlakar P Rajurkar,et al.  Micro and Nano Machining by Electro-Physical and Chemical Processes , 2006 .

[5]  Allen J. Bard,et al.  Electrochemical Methods: Fundamentals and Applications , 1980 .

[6]  Yoke San Wong,et al.  Towards a better understanding of the surface features of electro-discharge machined tool steels , 1990 .

[7]  Takahisa Masuzawa,et al.  Electrochemical surface finishing of tungsten carbide alloy , 1991 .

[8]  J. A. McGeough,et al.  Comparative studies of ecm, edm and ecam , 1981 .

[9]  Stephen T. Newman,et al.  State of the art electrical discharge machining (EDM) , 2003 .

[10]  B. Bhattacharyya,et al.  Advancement in electrochemical micro-machining , 2004 .

[11]  Liam Blunt,et al.  3D surface topography assessment of the effect of different electrolytes during electrochemical polishing of EDM surfaces , 2002 .

[12]  S. Yeo,et al.  Surface roughness model for micro electrical discharge machining , 2009 .

[13]  T. Sato,et al.  Fine surface finishing method for 3-dimensional micro structures , 1996, Proceedings of Ninth International Workshop on Micro Electromechanical Systems.

[14]  Takahisa Masuzawa,et al.  Quick Finishing of WEDM Products by ECM Using a Mate-Electrode , 1987 .

[15]  Takahisa Masuzawa,et al.  A Combined Electrical Machining Process for Micronozzle Fabrication , 1994 .

[16]  Mitsuro Hattori,et al.  A study of EDM and ECM/ECM-lapping complex machining technology , 2006 .

[17]  Mahmudur Rahman,et al.  An experimental study on micro-EDM in low-resistivity deionized water using short voltage pulses , 2012 .

[18]  Albert J. Shih,et al.  Near dry electrical discharge machining , 2007 .

[19]  Chong Nam Chu,et al.  Surface finishing of micro-EDM holes using deionized water , 2009 .

[20]  H. Hocheng,et al.  Effect of electrical discharge machining on surface characteristics and machining damage of AISI D2 tool steel , 2003 .

[21]  Han-Ming Chow,et al.  Micro-hole machining using micro-EDM combined with electropolishing , 2006 .