Comparative In Vitro Study of Ti-12V-9Sn Shape Memory Alloy with C.P. Ti and Ti-12V Alloy for Potential Biomedical Application

The microstructure, mechanical property and electrochemical behavior of Ti-12V-9Sn shape memory alloy was investigated, with commercial pure titanium (C.P. Ti) and Ti-12V as controls. The mestable β phase was partially retained in Ti-12V-9Sn alloy together with α'' martensite phase room temperature whereas only martensitic phases (α' and α'') existed in Ti-12V alloy at room temperature. Ti-12V-9Sn alloy exhibited a good combination of strength and elongation, which showed a “double yield” feature, moreover with a complete shape recovery strain of 4%. The electrochemical measurements indicated that all of the experimental samples exhibited excellent corrosion resistance in the artificial saliva with and without 0.2% NaF, among which Ti-12V-9Sn alloy possessed the lowest corrosion current density in both simulated body fluids.