The Heat-affected Zone in EDM and its Influence on a Following PECM Process

EDM (Electrical Discharge Machining) and PECM (Pulse Electrochemical Machining) provide unique possibilities for the machining of many different materials. Whereas EDM is able to machine any material above a minimal electrical conductivity, though with a certain degree of tool wear and heat influence, PECM has difficulties machining materials that build a passive layer or have chemically indissoluble contents. However, PECM has the advantage of working nearly wear-free. Based on this fact, a process chain can be built up that first structures copper electrodes by PECM and then uses them in EDM. When worn out, the electrodes can be restructured by PECM to keep a high reproducibility and constant quality of the machined geometry. In this contribution, the heat-affected zone of the tool electrode resulting from an EDM process and its potential influence on the machinability in the following PECM process are investigated for different copper alloys.