Effect of Aging Treatment on Microstructure and Mechanical Properties of Ti27Nb2Ta3Zr β Titanium Alloy for Implant Applications

This work aims to clarify the influence of aging temperature and time on the microstructure and mechanical properties of the Ti-Nb alloy for biomedical applications. The ingot of Ti-27Nb-2Ta-3Zr alloy was subjected to the arc melting, hot-forging and heat treatment respectively. Microstructure characterization was investigated by optical microscope (OM), X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM). The tensile tests showed an upward trend of the volume fraction of omega phase and alpha phase with the increase of aging time. When the aging temperature was higher than 673 K, the amount of ellipsoid-shaped omega phase precipitation decreased and needle-like alpha phase appeared, which contributed to higher tensile strength, lower Young's modulus and better plasticity.