Design of uniform nano α precipitates in a pre-deformed β-Ti alloy with high mechanical performance

Abstract

A strategy for the microstructural design to achieve a critical upper limit of uniform nano α precipitates by controlling the amount of dislocations in the pre-deformed matrix after short time aging treatment was proposed in Ti–10Mo–8V–1Fe–3.5Al (all in wt.%, TB3 alloy) β alloy. The optimal processes focused on the interaction of defects, mainly point defects and dislocations that are generated during cold rolling (CR). Texture evolution of α and β phases was also specified. Amount of nano-scaled α precipitates was characterized by the number density of precipitates observed by SEM, which is saturated at ∼204.1 μm−2. For the CR 20% sample, a good combination of tensile strength (∼1400 MPa) and elongation (∼12%) was achieved after secondary aging at 550 for 1 h, which provides an enlightenment for the re-engineering of traditional precipitate-hardening alloys. Keywords: β-Ti alloy, Short-time aging saturation, Uniform α precipitates, Mechanical properties