Review on non-conventional machining of shape memory alloys

Shape memory alloys (SMAs) are the developing advanced materials due to their versatile specific properties such as pseudoelasticity, shape memory effect (SME), biocompatibility, high specific strength, high corrosion resistance, high wear resistance and high anti-fatigue property. Therefore, the SMAs are used in many applications such as aerospace, medical and automobile. However, the conventional machining of SMAs causes serious tool wear, time consuming and less dimensional deformity due to severe strain hardening and pseudoelasticity. These materials can be machined using non-conventional methods such as laser machining, water jet machining (WJM) and electrochemical machining (ECM), but these processes are limited to complexity and mechanical properties of the component. Electrical discharge machining (EDM) and wire EDM (WEDM) show high capability to machine SMAs of complex shapes with precise dimensions. The aim of this work is to present the consolidated references on the machining of SMAs using EDM and WEDM and subsequently identify the research gaps. In support to these research gaps, this work has also evolved the future research directions.