Abstract: Influences of solution and aging treatment on microstructure, mechanical properties and corrosion resistance of near-β titanium alloy (Ti-3Al-6Mo-2Fe-Zr) were studied by means of optical microscope (OM), scanning electron microscope (SEM), X-ray diffraction (XRD). The results show that with the increase of solution temperature, the content of primary α phase gradually decreases. After solid solution treatment at 930 ℃, the alloy phase composition becomes a single β phase. When the solution temperature is below 830 ℃, the primary α phase gradually transforms into β phase with the increase of solution temperature. The strengthening effect of the second phase is weakened, resulting in a decrease in strength and an increase in plasticity. When the solution temperature is above 830 ℃, the β-phase grains gradually coarsen with the increase of solution temperature, leading to a decrease in strength and plasticity. The fracture mode also changes from micropore coalescence fracture to cleavage fracture. The corrosion resistance is improved as a result of the decrease of content of α phase and β/α phase boundary, as the solution temperature increases from 780 ℃ to 930 ℃. After the solution treatment at 780 ℃ for 1 h followed by water quenching and aging treatment at 500 ℃ for 6 h followed by furnace cooling, the fine needle-like secondary α phase precipitates within the metastable β phase, resulting in an increase in strength and a decrease in plasticity.

Key words: near-β titanium alloy, solution and aging treatment, microstructure, mechanical properties, corrosion resistance