Effect of Solution Treatment on Microstructure and Selected Mechanical Properties of an (α+β) Titanium Alloy

Abstract

The influence of solution treatment on the microstructure and mechanical properties of an (α+β) high temperature titanium alloy (Ti-6.5Al-2Sn-4Zr-5Mo-1W-0.2Si) are investigated by optical microscope (OM), scanning electron microscopy (SEM), electron probe microanalysis (EPMA) and tensile tests at room and elevated temperatures. The results shows that, Ti-6.5Al-2Sn-4Zr-5Mo-1W-0.2Si alloy after simple solution treatment has good combinations of plasticity and tensile strength both at room and high temperature. With the solution temperature increasing, the volume fraction of primary α phase (αp) decreases gradually, while the volume fractions of β matrix (βt) and secondary α phase (αs) increase. Room and high temperature tensile properties are insensitive with microstructure after solution treatment. With the solution temperature increasing, the content of αp phase decreases while the content and size of βt increase, which would cause the strength increase and plasticity decrease at RT and 650°C.