Microstructure refinement and properties of as-cast Ti-6Al-4V titanium alloy

doi:10.13251/j.issn.0254-6051.2025.02.008

Abstract

Abstract: Microstructure of the as-cast Ti-6Al-4V titanium alloy was refined by deformation combined with heat treatment. Firstly, the as-cast Ti-6Al-4V titanium alloy was subjected to solution treatment at 1100 ℃ and water cooling to transform the microstructure into martensite. Then, the microstructure was refined by repeated rolling at 750 ℃. The results show that the principles of microstructure refinement are the deformation twinning, dislocation rearrangement, crystal rotation and discontinuous dynamic recrystallization.Through tensile test, it is found that compared to the as-cast Ti-6Al-4V titanium alloy, the alloy treated with microstructure refinement has a better strength-plasticity matching relationship. The improvement of alloy strength is the result of the combined effect of fine grain strengthening and dislocation strengthening. The improvement of plasticity is due to the formation of a plastic zone at the crack tip during crack initiation and propagation, which hinders crack propagation and enhances the plasticity of the material. In addition, dislocations can complete slip transmission between the α and β phases, which can better coordinate the deformation between the α and β phases and further enhance the plasticity of the material.

Key words: as-cast Ti-6Al-4V titanium alloy, microstructure refinement, tensile properties, in-situ tension

CLC Number:

TG146.2⁺3

Sun Hao, Meng Xun. Microstructure refinement and properties of as-cast Ti-6Al-4V titanium alloy[J]. Heat Treatment of Metals, 2025, 50(2): 52-60.

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