Research on thermal stability of Ti40 alloy at 550 °C

Microstructures and mechanical properties of Ti40 alloy thermal exposures at 550 °C for different times were studied. The results show that there are only a few precipitates during thermal exposure, most of which distribute on grain boundaries and weakens its mechanical properties. By systematic analysis on its microstructures and mechanical properties, the thermal exposure at 550 °C can be divided into three stages and the formation and growth of the precipitates were different at each stage. During the third stage, the main reason of un-matched properties between strength and hardness is due to the formation of continuous precipitated zones along grain boundaries.