Effect of Solution and Aging Treatments Parameters on Microstructure and Mechanical Properties of Laser Additive Manufactured Ti-10V-2Fe-3Al Metastable β

Improvement of the mechanical property of the near-β titanium alloy Ti-10V-2Fe-3Al (TB6) fabricated by laser additive manufacturing can be achieved through solution and aging treatment. In this paper, the changes in the microstructures and mechanical properties of the deposited TB6 specimens were tested by changing the solution temperature, aging temperature, and aging time and the effects of the primary α phase (α_p) and secondary α phase (α_s) on the mechanical properties were analyzed. The results show that the solution temperatures mainly determine the volume fraction of α_p and grain boundary α phase (α_GB). Aging temperature and time have large impacts on the morphology of α_s. The strength of the solution- and age-treated specimens are controlled by the volume fraction and size of α_s. The higher volume fraction, α_s, obtained by the higher solution temperature could lead to a higher strength with balanced ductility. The coarser α_s obtained by the higher aging temperature or longer aging time will contribute to higher ductility, but decrease the strength of the alloy. The fracture mode of tensile specimens is mainly intergranular fracture due to the strain incompatibility between the grains and the grain boundaries.