High Temperature Mechanical Properties of Ti-Al-Nb Alloys with Different Phase

Three kinds of Ti-Al-Nb alloys (single-phase ,double-phase and triple-phase)were prepared by changing the contents of Ti,Al and Nb.Compressive and tensile tests were used to investigate the mechanical properties at room temperature to 1 373 K.The characteristics of microstructure and the tensile fracture surface were analyzed and observed kuch with XRD and SEM.The results showed that the compressive yield strength of Ti-47.5Al-5Nb alloy was 450 MPa at room temperature,neraly the same to the yield strength at 1 200 K.The data of Ti-42.8Al-14.2Nb alloy and Ti-40Al-20Nb alloy were 1 150 MPa and 950 MPa at room temperature,respectively.The compressive yield strength decreased quickly with increasing temperature above 1 200 K.Ti-42.8Al-14.2Nb alloy had good plasticity and yield strength at high temperatures.