Effect of Various Annealing Temperature on Microstructure and Properties of Metastable β-Type Ti-35Nb-2Ta-3Zr Alloy for Biomedical Applications

Microstructure and properties of a metastable beta-type Ti-35Nb-2Ta-3Zr alloy after cold rolling plus annealing at various temperatures were investigated systematically. The X-ray diffraction results show that the sample annealed at 923 K is mainly composed of the beta phase (92.3%). However, the samples annealed at 723, 823, and 1023 K contain a large amount of alpha '' phase of 39.6, 36.5, and 39.4%, respectively. The elastic modulus of the sample annealed at 923 K is about 50.1 GPa. However, these of the samples annealed at 723, 823, and 1023 K are 73.7, 56.1, and 70.2 GPa. Furthermore, the sample annealed at 923 K presents the best elasticity and the highest recovery strain (similar to 66.87%). The corrosion rate of the sample annealed at 923 K (similar to 2.403 mu m.a(-1)) is the lowest among all the samples, which may be attributed to its minimum content of alpha '' phase.