Numerical Simulation and Experimental Research on Wire Electrical Discharge Machining of NiTi Shape Memory Alloy

The surface quality and material removal rate of NiTi shape memory alloy (NiTi-SMA) wire electrical discharge machining (WEDM) are affected by discharge current, pulse width, flushing pressure and other factors. In this paper, a series of univariate experimental analyses were carried out. Based on the theory of heat transfer field and flow field, a numerical model for the machining process of NiTi-SMA WEDM is established. Combining experimental and simulation results, the law that the material removal rate and surface quality are affected by each process parameter is obtained. Discharge current and pulse width are the main factors affecting surface quality and material removal rate. Flushing pressure is the cause of the asymmetric distribution of the discharge pits.