Surface characteristics of Ti-6Al-4V alloy by EDM with Cu-SiC composite electrode

Ti-6Al-4V alloy is widely used in many industries due to its outstanding properties. However, it has poor machinability using conventional mechanical cutting process. Electrical discharge machining is an alternative competitive process to machine titanium alloy by electrical erosion. This article studies the machining characteristics of Ti-6Al-4V with Cu-SiC composite electrode. Surface topography, subsurface microstructure, energy dispersive spectroscopy analysis, and micro-hardness have been analyzed. The machined surfaces show irregular compound structures, droplets of debris, shallow craters, and micro-pores. The surfaces processed by Cu-SiC electrode have fewer number of microcracks compared with that by Cu electrode. Continuous and uniform hardened layer can be achieved by Cu-SiC electrode. The hardened layer has significantly higher hardness than the bulk material because the new phases of TiC and TiSi2 were created on the surface.