High fatigue endurance limit of a Ti-based metallic glass

In this work, we investigated the three-point bending fatigue behavior of a brittle Ti32.8Zr30.2Ni5.3Cu9Be22.7 MG (ZT3) combined with damage morphology observation using scanning electron microscope. It is found that the brittle ZT3 MG possesses the excellent fatigue resistance with the fatigue endurance limit of similar to 527 MPa based on stress amplitude, and the fatigue ratio of similar to 0.29 termed as fatigue endurance limit divided by ultimate tensile strength, respectively. The superior fatigue property of ZT3 MG is mainly clarified based on shear-banding mechanism. The embrittlement suppresses shear band formation before fatigue crack initiation, probably delaying the fatigue crack initiation; the profuse shear bands as well as the staircase-like crack path during fatigue crack propagation further increases the resistance to fatigue damage and fracture. Besides, the fatigue behavior of ZT3 MG shows a lessened sensitivity to the defect, as evidenced by the slightly decreased fatigue lives and the low scatter of fatigue data in stress-life (S-N) curve. The ZT3 MG with excellent fatigue performance as well as high specific strength is expected to be a prime candidate material for structural applications in future.