Study on the effects of short electric arc milling on TC4 machining performance

Short electric arc milling (SEAM) is a new type of discharge machining

method to efficiently remove difficult-to-machine conductive materials. Different electrode materials were used to carry out short electric arc milling experiments on titanium alloy TC4, and the influences of different discharge parameters (voltage, frequency, duty ratio) on material removal rate (MRR) and relative tool wear rate (RTWR) during machining were explored. Furthermore, the macro and micro morphology of the workpiece, the change of elements and the determination of hardness are analyzed. The experimental results shows that the factors affecting MRR and RTWR is pulse voltage, pulse duty ratio, pulse frequency. Copper electrode has high material removal rate and good surface quality. There are recast layer, droplet and micropore structures on the machined surface. The surface microhardness decreases gradually from the recast layer to the substrate, and tends to be stable at 90μm from the workpiece surface depth. It is proved that metal electrode materials are more suitable for SEAM processing titanium alloy materials, which provides a theoretical basis for SEAM processing titanium alloy parts in the future.