The Study On Fatigue Behavior And Its Fracture Mechanisms Of TiAl-based Alloy

The fatigue crack propagation (FCP) rates and thermomechanical fatigue are considered in this paper. The FCP rates are tested at 20℃ 650℃ and 800℃ with different stress ratios . The study on TMF is conducted under different waves, temperature ranges, stess levels. The effects of all kinds of factors on the mechanisms of fatigue frature are analyzed by SEM and TEM technology. Additionally, the thermal fatigue of this alloy are also discussed in this paper.The results show that, the alloy of Ti-46.5Al-5Nb with nearly fully lamellar structure at cast condition appears excellent FCP resistance , good TMF and thermal fatigue properties. The application of Ti-46.5Al-5Nb alloy take a important role in the fields of aerospace and automobile.