Developments on electrochemical discharge machining: A review of experimental investigations on tool electrode process parameters

The electrochemical discharge machining is a combination of electrochemical machining and electrical discharge machining. The machining is achieved by chemical etching effect and melting of workpiece material due to electrical discharges. This process is used for a variety of nonconductive materials (glass, quartz, ceramic, Pyrex and so on) for the purpose of micromachining and specially for micro electro mechanical system applications. This article presents a comprehensive review of recent developments on tool electrode process parameters, which have resulted in enhanced efficiency and accuracy of the machining process. The tool electrode process parameters are shape, size, roughness, insulation and motion of tool and so on. These process parameters affect the process performance in terms of material removal rate, surface quality and dimensional accuracy of micromachined products. For example, spherical tool geometry provides five times higher material removal rate as compared to cylindrical tool geometry. The impact of electrochemical discharge machining process parameters associated with tool electrode is also discussed. A summary of review and proposed research directions is presented in this article.