Microstructure and Properties of Ti-6Al-4V-0.1B Alloy under Different Heat Treatment

The relationship of microstructure and properties of Ti-6Al-4V-0.1B alloy rolled at α + β phase region is studied with different heat treatments.The results show that heat treatment at α + β phase region results in equiaxed or bimodal microstructures.The volume fraction of primary α phase decreases with increasing solution temperature.The strength of Ti-6Al-4V-0.1B alloy with Widmannstätten microstructure treated at β phase region is higher than that with duplex microstructure, but the plasticity is just opposite.During β heat treatment, original β grain size and α colonies increase with solution temperature raise.The optimized heat treatments are as 900 ℃/1h, AC + 540 ℃/8h, AC;and 1 080 ℃/1h, AC + 540 ℃/8h, AC.During the tensile deformation process, the TiB phases undertake loading transition and have good bonding force with the matrix.