Electrical discharge machining characteristics of Ti-6Al-4V alloy.

Abstract

In order to reveal the electrical discharge machining (EDM) of titanium alloy, a series EDM tests on commercial product Ti-6Al-4V with graphite and copper used as the tool electrode materials were carried out at different parameters such as discharge current and pulse duration. The relationships between these factors and material removal rate, surface roughness, enlargement and heat-affected layer were investgated. The following main results were obtained. From the view point of metal removal rate using graphite electrode with negative polarity is remarkably larger than the copper electrode. But from the view point of surface roughness copper electrode is better than graphite electrode. The thickness of heat-affected layer increases with increasing pulse duration and discharge current, especially, when the pulse duration is large enough, the heat-affected layer becomes severely.