Microstructural, mechanical and biological characterizations of the promising titanium-tantalum alloy for biomedical applications

In this study, the microstructural, mechanical and biological characterizations of the Ti-25Ta (wt.%) alloy were investigated by means of optical microscope, X-ray diffraction, electron microscope, microhardness test, contact angle goniometer and in vitro cytotoxicity assay. As the alloy underwent heat-treatment at temperatures between 700 °C and 1000 °C for 30 min, its microstructure was a mixture of β phase and needle-like α′′ martensite phase. The analytical results indicated that the volume fraction of the needle-like α′′ martensite phase decreased with increasing heat-treatment temperature. The β transus temperature of the investigated Ti-25Ta alloy was below 700 °C. Moreover, the alloy heat-treated at 900 °C exhibited the maximum hardness Hv 743 ± 12.93. For wettability evaluation, all investigated samples possessed surface hydrophilicity. The cytotoxicity assay results also demonstrated that the heat-treated Ti-25Ta samples have well cell proliferation and adhesion behaviors. Therefore, these results and features could be used to further understand the relationship between the high temperature microstructure, mechanical behavior and in vivo biocompatibility of the Ti-25Ta alloy, and develop as a potential biomedical alloy.