Abstract:
The most crucial cost element of Electric Discharge Machining (EDM) is the production of tool electrode (shortly electrode). Copper, its alloys, and graphite are the most commonly used electrode materials. Selecting the proper electrode material with low production and material cost, high workpiece material removal rate (MRR) and low tool electrode wear rate (TWR) is key to reducing machining costs with EDM. In this study, the EDM performance of CuBe tool electrodes in the machining of Ti6Al4V alloy was experimentally investigated in comparison to electrolytic Cu (E-Cu) electrodes for different pulse time (ts) and discharge current (I) settings. An increase in MRR and a decrease in TWR and relative wear (RW=TWR/MRR) were observed in machining with CuBe electrodes. However, the high raw material cost of CuBe alloy is an essential drawback in widely using these electrodes in industrial applications. A new performance index formulation is introduced for EDM applications that factor in the production cost of the electrode and its life (i.e., RW). According to our results, the CuBe could be used advantageously as the electrode material at medium current settings. However, at low and high current settings, the low raw material cost of E-Cu makes it more favorable.
