Electrochemical discharge machining for fabricating holes in conductive materials: A review

With the increasing requirements for accuracy and integrity of machining under severe application environment, electrochemical discharge machining (ECDM) has evolved continuously for fabricating micro-holes. The method can be categorized into two types based on whether the material being machined is electrically conductive or non-conductive. Most research to date has been focused on non-conductive materials, with numerous introductory review articles. However, despite a growing number of studies of machining conductive materials, there is a lack of systematic analyses and summaries. Therefore, the purpose of this paper is to fill an important gap in the literature by presenting a comprehensive review of the research and development of ECDM technology for processing conductive materials, especially micro-holes. First, the characteristics of this method are summarized. Second, the development of this method and the mechanism of discharge are compared and analyzed. Third, a discussion is given on how machining performance is affected by parameters such as solution conductivity, electrical parameters, tool electrode structure, and workpiece material. Also, to enhance the machining quality, some auxiliary ECDM measures are presented. Finally, future prospects and trends of ECDM are identified.