In-vitro mechanical behavior and high cycle fatigue characteristics of NiTi-based shape memory alloy wire

Pseudoelastic NiTi-based shape-memory-alloy is a popular candidate for miniaturized biomedical components. Such material undergoes reversible stress-induced-phase-transformation resulting to significant recoverablestrain - 10%. In this study, the effect of corrosion, bio-fluids, fatigue mean-stress, stress-ratio and occurrence of functional-fatigue on the in-vitro performance of the NiTi system are carefully scrutinized. Systematic experiments are performed using specialized capstan-grip and customized bio-chamber in presence of relevant biofluids at human body-temperature. The alloy revealed excellent pseudoelastic plateau-strain along with a combination of optimally high ultimate tensile strength and ductility. Interesting insights developed from the study are beneficial for considering the biomedical usage of the alloy.

Automated summary

This study carefully examines the in-vitro performance of the NiTi system under conditions such as corrosion, bio-fluids, fatigue mean-stress, stress-ratio, and functional-fatigue. The alloy shows excellent pseudoelastic plateau-strain and optimal combination of ultimate tensile strength and ductility, providing valuable insights for its biomedical application.