Development and Surface Engineering of TiNi Shape Memory Alloy

Abstract

Shape memory alloys are currently replacing many conventional materials due to their various useful properties. Besides shape recovery above austenitic temperature and pseudo-elasticity, high strength and good corrosion properties are one of the many mentionable properties of these alloys. Due to their intriguing properties, aerospace, biomedical and automotive industries are leading the research frontier for these smart materials. This chapter presents the results of an experimental investigation conducted on development of Ti rich shape memory alloy by arc melting and hot rolling, and its surface study when machined by wire-EDM. The developed and machined specimens of TiNi alloys were also tested. Tensile study of the specimens showed that material rigidity has decreased due to intensive rolling process. Scan electron microscopic analysis of the fractured surface confirmed that the mode of failure of the rolled specimen was ductile in nature. Characteristic properties like necking, dimple formation, cracks which are related to ductile failure of metallic materials are clearly visible in the SEM micrographs. Micro hardness test revealed that micro hardness of the rolled specimens are much higher than as cast TiNi alloy and less along the edge of the fracture surface compared to bulk rolled material. © 2020, Springer Nature Switzerland AG.