The effect of Fe element on the microstructure and mechanical properties of TC4 titanium alloy

This article mainly studies the effect of Fe content on the microstructure and mechanical mroperty of TC4 titanium alloy. Comparative analysis was conducted on the room temperature tension, 400℃ high temperature tension, room temperature impact, and metallographic microstructure of TC4 sample 1 with 0.05% Fe added and TC4 sample 2 with 0.23% Fe added after the same forging and heat treatment. The results indicate that increasing the Fe content（about 0.2%, mass fraction） is beneficial for primary growth α phase content decreased by about 9%. And secondary α phase thickness increases and they are arranged in a chaotic and intersecting manner. The strength of room temperature stretching, room temperature impact, and 400℃ high temperature stretching is significantly improved. The tensile strength and yield strength at room temperature increased by approximately 55MPa. The tensile strength increased by about 30MPa for 400℃ high-temperature stretching. This is because during the stretching process, the obstacles encountered during the slip of dislocations are enhanced, resulting in a large number of dislocations accumulating in the dispersed strengthening phase; At the same time, with the increase of Fe element,significant lattice distortion occurs when forming a solid solution with titanium alloy, which can also improve the strength of titanium alloy. But it has no significant effect on the plasticity of room temperature stretching and 400℃high-temperature stretching.