Effects of Solution Treatment on Microstructure Evolution and Mechanical Properties of Ti-22Al-24Nb-0.5Mo Alloy

As-rolled Ti-22Al-24Nb-0.5Mo sheets were subjected to various solution treatment systems to improve their microstructural and mechanical properties. The effects of solution temperature and holding time on the evolution of microstructure, mechanical properties, and fracture behavior were analyzed. The analysis involves studying the variations in second-phase content, grain boundary evolution, globularization of the lath α 2 phase, texture evolution, and changes in performance based on second-phase content and aspect ratio. Microstructure statistical analysis and mechanical property induction techniques were employed. Additionally, fracture mechanisms were identified through fracture behavior analysis. Microstructure evolution and tensile fracture models were constructed. Results indicate that the O phase rapidly dissolves in the B2 matrix within the temperature range of 990-1050 °C, leading to the globularization of the lath α 2 phase. The proportion of low-angle grain boundaries and texture intensity peak at 1020 °C. The yield strength and elongation of nearly all the sheets significantly increase after solution treatment except at 1050 °C for 45 min. The brittle fracture characteristics of the sheets gradually manifest as the solution temperature increases.