Effects of Heat Treatment on Microstructure and Property of Cast Ti-18Al-10Nb Alloy

The effects of heat treatment temperatures and cooling method on the cast microstructure and mechanical properties of Ti-18Al-10Nb alloy were studied. The results indicate that the microstructure of Ti-18Al-10Nb alloy is composed of α₂ phase and β phase in cast condition. During the heat treatment process, the content and the thickness of α₂ phase reduce accompanied by the compressive properties of the alloy decrease as the solution temperature rlse. The compressive strength of Ti-18Al-10Nb alloy as cast condition is 1454 MPa, while alloys carried out at 985 ℃ for 1 h with air cooling, the compressive strength of alloy is 1355 MPa and the compressive strain is 0.047, which is 68.5% lower than that of the cast condition. The compression strength of water-quenched alloy increases at the same heat treatment temperature. After 785 ℃ for 1 h with water quenching, the compressive strength of the alloy is 1210 MPa, however, the compressive strength of the alloy with air cooling is 1178 MPa.