Research on the influence of loading frequency on the very high cycle fatigue performance of TC17 postprint

Abstract: TC17 titanium alloy is a typical material for aeroengine blades and discs, and its very high cycle fatigue performance is directly related to the long life and high reliability design of the aeroengine. The very high cycle fatigue performance of TC17 was studied using four test methods: conventional tensile-compression, conventional bending, accelerated tensile-compression, and accelerated bending. The conventional test frequency was (1.500±500) Hz, and the accelerated test frequency was (20±1) kHz. Fatigue test data of TC17 in the life range of 5×105-2×109 were obtained, and its fatigue strength were mainly concentrated in the range of 400-570 MPa. Through analysis of different types of test data, it is found that the loading frequency has little effect on the very high cycle fatigue performance of TC17, and the bending fatigue strength is higher than the tensile-compression fatigue strength. Fracture analysis shows that the loading frequency has no significant effect on the fatigue crack initiation and growth mechanism of TC17.