Effect of Solution Temperature on Tension-Compression Asymmetry in Metastable β-Titanium Alloys

Abstract

Three titanium alloys, Ti-10V-1Fe-3Al, Ti-10V-2Fe-3Al and Ti-10V-2Cr-3Al, were heated by solution treatment at in 700 °C (α + β phase region), 800 °C (near β phase region), 900 °C and 1000 °C (single β phase region). The effects of solution temperature on the microstructure and mechanical properties of the alloys were studied, and the mechanical asymmetry of tension and compression of three titanium alloys was analyzed; the results show that the microstructure of the three alloys changes regularly with the increase of solution temperature. Different solution temperatures have a significant effect on the compressive and tensile properties of the three alloys. During compression deformation, the stress-induced martensite transformation occurs in samples with solution at 800 °C and above; however, there is no phase transformation during the process of tensile tests. The asymmetry of yield strength, work hardening rate and final strength of the three alloys are obvious during compression deformation and tensile deformation. The difference in the number of twins between uniaxial tension and uniaxial compression, the presence or absence of stress-induced martensitic transformation, and the CRSS asymmetry of cone <c + a> slip may be the reasons for the asymmetry of mechanical properties.