Study of shape memory properties of Ti₍₅₀₎Ni_(50-x) M_x (M= Nb, Mo and Fe) alloys for biomedical applications using first principle approach

Abstract

The discovery of TiNi binary alloys has revolutionised the scientific and industrial communities more so in biomedical applications due to their excellent shape memory properties and biocompatibility. When TiNi is exposed to an external stimulus such as stress or temperature change, the material is able to recover its original structure after significant or quasi-plastic deformation. The aim of this study was to investigate the shape memory properties of TiNi(50-x)-Mx (M = Nb, Fe, Mo) alloys. In this study, CASTEP was used to perform first-principles calculations and to predict shape memory behaviour and biomechanical properties of these alloys. The results showed a decrease in the formation energy of Ti8Ni7Fe1. The poisons ratio was increasing significantly to the value of 0.39 corresponding to the G/B results. Initial fermi levels increased with the addition of a ternary alloy. Ti8Ni7Fe1 proved to be the best candidate for replacing TiNi alloys.