Effect of aging temperature on microstructure and mechanical properties of Ti-Nb-Ta-Zr-Fe alloy for biomedical applications

The effect of aging temperature on microstructure and mechanical properties of Ti-25Nb-10Ta-1Zr-0.2Fe alloy was investigated. The results showed that the solution treated sample possesses good plasticity behavior. The deformation mechanism of the solution treated sample during tensile process is stress induced martensite transformation from beta phase to alpha" phase. An increase in yield strength as well as a great decrease in plasticity is observed in the alloy after aging treatments owing to the precipitates forming barriers against dislocation slip. The precipitation of omega phase in (3 phase at relatively lower aging temperature between 150-400 degrees C leads to low strength-to-modulus ratio and low elongation, whereas the precipitation of a phase at relatively higher aging temperature of 550 degrees C results in high strength, low Young's modulus and moderate elongation.