Nowadays, numerous metallic alloys are known to exhibit smart behavior;
these metallic materials are categorized as shape memory alloys (SMAs). Shape
memory alloys belong to a group of smart alloys that have the potential to recover their
original shape from a deformed shape when triggered by factors, such as heat,
electricity, and stress. This shape change gives rise to SMART behavior (Stimulated
Martensite - Austenite Reverse Transformation). Shape memory alloys have attractive
characteristics, such as high recovery force, high strength, etc. Shape memory alloys
find their use in many applications i.e., aerospace, biomedical, automobile, robotics,
etc. The ever-increasing demand for shape memory alloys among industries is
attributed to their ability to respond to different machining processes. Conventional
machining processes (CM) and unconventional machining (UCM) processes are the
two major types of processes upon which the studies on shape memory alloys have
been carried out. The machining studies carried out reveal that the use of conventional
machining to process shape memory alloys to various products is considered
undesirable since it causes damage and introduces changes in the characteristics of the
material. Unconventional machining processes are therefore preferred. Various types of
unconventional machining processes like laser beam machining (LBM),
electrodischarge machining (EDM), electrochemical machining (ECM), abrasive jet
machining (AJM), abrasive water-jet machining (AWJM), etc., generally involve
machining of shape memory alloys in an unconventional way so that the wear rate and
surface roughness are reduced. A study of unconventional machining processes is
therefore considered essential contributing further to the domain of smart materials.
Hence, through this review, the mechanism of shape memory alloys and their
applications, various types of unconventional machining processes, and their recent
advances are highlighted.
Keywords: Abrasive water jet machining, Electrochemical machining, Electrodischarge machining, Laser beam machining, Martensitic transformation, Superelasticity, Shape memory alloys, Shape memory effect.
