A Review on Present Status of Friction Stir Welding of Nitinol, a Functionally Advanced, Versatile and Widely Used Shape Memory Alloy

Abstract

Ni-Ti alloys are extensively utilized in different fields of manufacturing because of their typical pseudoelastic effect and the shape memory properties. Welding of NiTinol is always essential to manufacture diverse geometrical structures with sufficient design flexibility following the application necessities. NiTinol is susceptible to compositional variations and microstructural changes because of the welding process. As a result, the mechanical and microstructural properties along with other functional properties get deteriorated with time. Welding of NiTinol without melting is extremely substantial because of the avoidance of the volatilization of the compositional constituents. Friction stir welding, a solid-state welding method, satisfies all the vital necessities of NiTinol alloy welding. This chapter will describe the friction stir welding of NiTinol in both similar and dissimilar material combinations in detail. The effect of different welding process variables on mechanical and metallurgical properties will be described along with the description of the smart functionality of the welded structures and the corrosion resistance performance.