Effects of Different Electrode Materials on High-speed Electrical Discharge Machining of W9Mo3Cr4V

Abstract

In order to break through the limit in material removal rate (MRR) of electrical discharge machining (EDM), electric arc machining (EAM), as a new and high-speed processing method, is used to machine difficult-to-machine materials. This method has an exciting high MRR with tens times increase in EDM and a low relative electrode wear ratio (REWR) when machining W9Mo3Cr4V. The electrode material is an important factor that affects the processing cost and quality of EAM. In this paper, traditionally conductive metal materials were used as electrode materials to process W9Mo3Cr4V in EAM, including brass (H62), copper (T2), stainless steel 304, aluminum alloy 6061 and graphite (C). Experimental results show that tubular graphite (C) is the best electrode material for EAM. Additionally, when tubular graphite with 16mm external diameter and 12mm internal diameter is used as tool electrode, the effects of processing parameters (peak current, electrode polarity, electrode speed and flushing pressure) are also investigated in present study. MRR, REWR, white layer thickness (WLT) and surface roughness (Rz) are selected as output responses.