Modulating fatigue property of in situ Ti-based metallic glass composites by changing dendrite composition

Metallic glass composites (MGCs) serve as promising candidates of advanced structural materials. In this work, the Mo element was added to change the dendrite composition of in situ dendrite-reinforced Ti-based MGCs, for exploring the effect of dendrite composition on fatigue behavior. The Mo-containing MGC possessed the lower fatigue lives and fatigue endurance limit, relative to Mo-free MGC. Several characterization methods including X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) were utilized to reveal the fatigue deformation and damage features. The Mo could change the dendrite stability and then induce the fatigue deformation variation from martensitic transformation and twinning to dislocation slipping. The fatigue crack formed from the metallic glass (MG) matrix phases and deflected when encountering the dendrites in Mo-free MGC; for comparison, the fatigue crack formed from the dendrites and penetrated the adjacent MG matrix and dendrites in Mo-containing MGC. Current results may offer the guidance on future composition design for MGCs with excellent fatigue property.

Automated summary

In this study, the addition of molybdenum element was used to change the dendrite composition of in situ dendrite-reinforced metallic glass composites (MGCs) to investigate the effect on fatigue behavior. The results showed that MGCs containing molybdenum had lower fatigue lives and fatigue endurance limit compared to molybdenum-free MGCs. Characterization methods such as X-ray diffraction, scanning electron microscopy, and transmission electron microscopy were employed to reveal the fatigue deformation and damage features. The presence of molybdenum altered the dendrite stability and induced a change in fatigue deformation mechanism from martensitic transformation and twinning to dislocation slipping.