One of the fundamental problems of Electrical Discharge Machining (EDM) process is tool electrode wear. In this study, ultra fine grains (UFG) structure of pure copper was used to improve performance and also increase the electrical wear resistance of tool electrode. Equal Channel Angular Pressing (ECAP) was used to reduce the crystal size of pure copper. Samples were processed through ECAP die up to 8 passes, and then used as electrode in EDM process. The effect of electrodes grain size, discharge current, and machining time on the metal removal of the work piece and electrical wear of the electrodes were investigated. In addition, the microstructure, and electrical conductivity of copper tool electrodes were examined. By applying the ECAP on pure copper a fine, approximately 50-200 nm grain size, microstructure was obtained after 8 passes. The results show that for finer crystalline structure of copper electrodes, electrical wear decreases but material removal rate is somehow constant.

Keywords: Electrical discharge machining, Tool Electrode Wear, Equal channel angular pressing, Ultra Fine Grained Copper

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