Effect of heat treatment on the corrosion-fatigue of NiTi shape memory alloy

Abstract

Nickel Titanium (NiTi) shape memory alloys have been considered convenient implant material due to their distinguished properties including superelasticity (SE), shape memory effect (SME) and biocompatibility. Among these properties, corrosion resistance is one of the most crucial factors that affect the reliability of NiTi in biomedical use. Understanding the corrosion behavior of NiTi alloy is important due to the necessity of controlling the risk of corrosion-based Ni release and corrosion fatigue for the successful long-term implantation. Heat treatment can strongly influence the mechanical properties including fatigue life for meeting the structural requirements of medical implants. In this study, the effect of heat treatment temperature on the corrosion-fatigue of NiTi shape memory alloy was investigated to validate its performance in simulated body fluid medium using a custom-manufactured experimental setup under cyclic loading. It was observed that the number of cycles to failure increase with increased treatment temperature.