Process Capability of Wire-EDM of NiTi Shape Memory Alloy at Main Cut and Trim Cut Modes

Nitinol is widely used shape memory alloy (SMA) in manufacturing medical devices, actuators, mechanical couplings, etc. However, mechanical cutting of Nitinol is exceedingly difficult to machine. Machining induced surface integrity of SMA has significant impacts on device performance. In this study, Nitinol was machined by wire electric discharge machining (Wire-EDM) in both CH-oil and deionized water (DI-water). Surface characteristic evolution was examined from main cut (MC), first trim cut (TC), to finish trim cut (FC) and compared with the traditional mechanical cutting.