Effects of thermal treatments on the microstructures and mechanical properties of Ti–5Nb–5Mo alloys

Abstract The aim of this study was to investigate the microstructure and mechanical properties of Ti–5Nb–5Mo alloy subjected to different heat treatments in an attempt to improve the bending strength/modulus ratios for the development of biometals for orthopedic and dental implant applications. The results show that the as-cast Ti–5Nb–5Mo alloy was composed mainly of the α″ phase, and the same phase could also be observed in the samples subjected to the ice water quenching and air cooling treatments. The α″ single-phase was also identified on the samples age-treated at 300 or 400 °C for 30 min. Both water-quenched and 400 °C-aged alloys with the α″ single phase showed much higher bending strength/modulus ratios (a value of 24.3 and 23.7, respectively) than was found in the as-cast and other heat-treated samples. Therefore, the cooling methods or subsequent aging treatment can be considered optimal heat treatment conditions for Ti–5Nb–5Mo alloy for use in orthopedic and dental applications.