NANOINDENTATION STUDY ON NiTi THIN FILM SHAPE MEMORY ALLOYS

A single bi-layered sample consisting of a monolayer of Ni and a monolayer of Ti with the Ni layer as a base layer was deposited on a silicon substrate. During deposition, the substrate was rotated at a predefined speed. The as deposited layers were then annealed at temperatures of 300 ¿ C, 400 ¿ C,500 ¿ C and 600 ¿ C, for a time period of 1 hour in a vacuum furnace in order to achieve crystallinity in the as deposited layers and form a crystalline single layer and also for the purpose of chemical homogeneity. The thesis deals with the process of manufacture of NiTi thin film shape memory alloys and the characterisation of their morphology as well as the mechanical properties of the thin films like hardness, reduced elastic modulus and hence the elastic modulus, wear rate and hence the wear resistance, depth recovery ratio and consequently the super elastic properties. The films were manufactured in a DC/RF magnetron sputtering machine on thoroughly cleaned Si substrate held at a temperature of 300 ¿ C from two 99.99 % pure 75 mm Ni and Ti target materials in an inert atmosphere made up of 99.99% pure Argon. During deposition, the substrate was rotated at a predefined speed. Tot