Effect of aging temperature on microstructure and properties of Ti–5Al–5Mo–5V–1Cr–1Fe alloy by hot isostatic pressing

Ti–5Al–5Mo–5V–1Cr–1Fe alloy was fabricated by hot isostatic pressing (HIP), and the effect of aging temperature on its microstructure and mechanical properties was investigated. The results show that the microstructure of the HIPed TC18 titanium alloy consists of equiaxed α phase, lath α phase, α_s phase, and a small amount of β phase. Solution and aging treatment can promote the precipitation of α_s phase from the β phase. When the aging temperature is 500 °C, the alloy achieves a tensile strength of 1341 MPa and a yield strength of 1267.5 MPa. As the aging temperature increases to 650 °C the content of α_s phase decreases and coarsening of the α_s phase occurs. Although this microstructural evolution leads to a reduction in the strength of the alloy, it significantly improves its plastic deformation capacity, resulting in an elongation of 22.25% and a reduction of area of 59%.