Thermal Stability and Mechanical Properties of Ti-15-3 Titanium Alloy

The microstructure stability and tensile properties of Ti-15-3 titanium alloy were investigated by aging the alloy at different conditions. The results showed that when the temperature was below 250°C, ω phase precipitates and the tensile strength increased with increasing aging time. Although there were a little of ω phase after aging at 200C for 1000h, Ti-15-3 alloy still presented good strength and ductility. When the aging temperature was 250°C~400°C, ω precipitation or β’ phase separation occurred from β matrix, and finally transformed to α precipitates. The tensile strength increased firstly and then decreased with increasing aging time. When aged at above 400°C, α phase precipitated fast from the alloy, and the strength increased gradually.