Milling performance of Ti2AlNb by DC short electric arc machining based on different electrode materials

In this paper, a novel efficient and sustainable electrical discharge machining method, referred to as short electric arc machining (SEAM), is proposed to solve the problems of low efficiency, severe tool wear, and high cost of Ti2AlNb machining by traditional methods. The mechanism of SEAM with different voltages and tool electrode materials (W70Cu30, high-purity graphite, copper-plated graphite, and 304 stainless steel) is studied using a DC power supply, and the workpiece material removal rate (MRR), surface roughness (Sa), and relative tool wear rate (RTWR) are analyzed. In addition, the surface morphology, cross-sectional morphology, elemental distribution, and microhardness of Ti2AlNb after processing are investigated. The experimental results show that under 28 V, the W70Cu30 electrode achieves the highest MRR of 2571 mm3/min, which is higher than that of the other three electrode materials. It has also the lowest RTWR of the electrode and a relative electrode loss of only 0.0974%. The lowest surface roughness and heat-affected layer of the workpiece after machining are 53.2 and 56.54 µm, respectively. The absolute difference of the width of the cross-section of the workpiece is the smallest, and the hardness of the recast layer of the workpiece is close to the hardness of the base metal, which is conducive to further processing.