Study on Creep-Fatigue Mechanical Behavior and Life Prediction of Ti2AlNb-Based Alloy.

Low-cycle fatigue, creep and creep-fatigue tests of Ti2AlNb-based alloy were carried out at 550 °C. Compared with low-cycle fatigue, a creep-fatigue hysteresis loop has larger area and smaller average stress. The introduction of creep damage will greatly reduce the cycle life, and change the fatigue crack initiation point and failure mechanism. Based on the linear damage accumulation rule, the fatigue damage and creep damage were described by the life fraction method and the time fraction method, respectively, and the creep-fatigue life of the Ti2AlNb-based alloy is predicted within an error band of ±2 times.