Abstract: Effect of solution treatment temperature (850, 820, 790, 760 ℃) on microstructure and mechanical properties of Ti-3.5Al-5Mo-6V-3Cr-2Sn-0.5Fe corrosion-resistant titanium alloy plate aged at 550 ℃ for 4 h was studied by means of scanning electron microscope, transmission electron microscope, X-ray diffractometer and tensile testing machine. The results indicate that the microstructure of both the original and heat treated titanium alloy plate is composed of equiaxed α phase and retained β phase. As the solution treatment temperature increases, the content of α phase decreases while the content of β phase increases. The heat treatment reduces the internal stress and dislocation density of the titanium alloy plate, thus improves the elongation. As the solution treatment temperature increases, the tensile strength of the aged titanium alloy first increases and then decreases, while the elongation is opposite. The titanium alloy solution treated at 820 ℃ and aged has the highest tensile strength, with tensile strengths of 1387 MPa and 1357 MPa in the RD and TD directions, and elongation of 3.7% and 4.1%, respectively.

Key words: corrosion-resistant titanium alloy, solution treatment, aging, microstructure, mechanical properties