TA15 titanium alloy has medium room temperature strength and high temperature strength, good thermal stability and welding performance. It is mainly used for aircraft and engine welding bearing parts with long working hours below 500 °C. The nominal composition of TA15 titanium alloy is Ti-6Al-2Zr-1Mo-1V, which has an aluminum equivalent of 6.33 and a molybdenum equivalent of 1.67, belonging to a high aluminum equivalent near α type alloy. The TA15 titanium alloy is generally used in an annealed state. With the application of parts of the TA15 titanium alloy subjected to impact loads on the aircraft, the stress and deformation caused by the instantaneous impact are much larger than those of the static load. Therefore, the impact properties of the material have attracted people's attention.
At 810-850 °C, the impact performance of TA15 titanium alloy decreases with the increase of heat treatment temperature. At the same temperature, the impact performance increases with the increase of holding time, and the impact performance increases with the increase of heat treatment temperature. The amplitude becomes larger. It shows that the TA15 titanium alloy bar can obtain higher impact performance after heat treatment at 810 °C × 2h, and the impact performance is improved by 35%. In the case where the shape and size of the primary α phase are substantially the same in the TA15 titanium alloy, the shape and size of the secondary α phase have a greater influence on the impact toughness. The impact value when the secondary α is a strip is significantly higher than the impact value when the secondary α is a circular or short rod.