Abstract: Effect of solid solution and aging treatment on microstructure, phase structure and mechanical properties of TC6 alloy was investigated via optical microscope (OM), scanning electron microscope (SEM), X-ray diffraction (XRD), Vickers hardness tester and mechanical properties testing system. The results show that the TC6 alloy is mainly composed of lamellar α phase, needle-like martensite α′ phase and β phase after solution treatment at 900 ℃. However, after solution treatment at 1000 ℃, the alloy is mainly composed of needle-like martensite α′ phase and β phase. During the aging process at different temperatures, the α′ martensite phase formed under water quenching is decomposed and transformed into α and β phases completely. Also, with the aging temperature increasing, the relative content of β phase increases gradually. By comparison, the overall mechanical properties of the TC6 alloy after solution treatment at 900 ℃ and aging at 500 ℃ are the optimal, with the compressive strength and yield strength being 2000 MPa and 1061 MPa respectively, and the hardness value being 499 HV0.2.

Key words: TC6 alloy, solution treatment and aging, microstructure, mechanical properties