High fatigue endurance limit of a metastable Ti-based metallic glass composite with martensitic transformation

Introducing the dendrite phase is an effective solution to overcome the low fatigue resistance of metallic glass (MG). In present study, we examined the four-point bending fatigue behavior of a new Ti50.32Zr33.92Cu4.56Ni2.12Be9.08 metallic glass composite (MGC) containing metastable dendrites. The stress-life (S-N) test and various characterization techniques including X-ray diffractometer (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM) were carried out. The fatigue endurance limit, defined as the maximum stress amplitude to which the sample is subjected for 107 cycles without failure, was measured to be -360 MPa in current MGC. Just compared to the four-point bending fatigue data in previously reported MGCs, the fatigue limit of current MGC is highest. Such excellent fatigue property results from the coupled effect of two aspects on the shear banding and fatigue damage behaviors, i.e., one is the fine separation between the dendrite phases and the other is the martensitic transformation of the metastable dendrites. These findings may improve the understanding on the fatigue mechanisms and provide a promising way for designing the MGs or MGCs with better fatigue performance.

Automated summary

Introducing dendrite phase has effectively improved the fatigue limit of metallic glass composite, leading to better fatigue performance. This may provide a promising approach for designing metallic glasses or metallic glass composites with improved fatigue performance.