Effect of Heat Treatment on Microstructure and Properties of Ti-6Al-4V-0.5Si alloy

Titanium and its alloys have excellent comprehensive properties, and have been widely used in aerospace, medical chemistry and other fields since the 20th century. Nowadays, high performance and low cost have become one of the main directions of research and development of titanium alloys in the world. The effects of insoluble aging temperature on the tensile strength, elongation, morphology and phase composition of Ti-6Al-4V-0.5Si alloy were analyzed. The results show that there are more hexagonal and oblique α martensite phases in Ti-6Al-4V-0.5Si alloy after solution treatment. After aging treatment, the martensite phase is decomposed and recrystallized to obtain dispersed α+β phase. Comprehensive analysis shows that the comprehensive properties of the alloy are the best when the solid solution aging process is 950℃×30min(WQ)+480℃×4h(AQ). The tensile strength and elongation of the alloy are 7456 MPa and 8.3% respectively, which are 24.8% and 36.0% higher than those before the solid solution aging treatment.