Effect of preloading treatment on dynamic mechanical properties of TiZr-based bulk metallic glass composite

Deformation-induced phase transformation behavior is beneficial for plasticity and work hardening ability of bulk metallic glass composites (BMGCs). In this study, the effects of preloading treatment on the microstructure and dynamic mechanical properties of a TiZr-based BMGC with deformation-induced phase transformation were systematically studied. The strength and impact absorption energy of the composite were improved after the preloading treatment. Under a pressure of 1000 MPa for 10 min, the composite exhibits the best dynamic mechanical properties. The composite has an impact absorption energy of 18.7 MJ m-3, 10 times that of the as-cast sample. These results are attributed to the preformation of martensite during the preloading treatment and increases in volume fraction and variant types of martensite during the final dynamic deformation process. Deformation-induced phase transformation can effectively release local stress concentration, refine beta phase grains, promote formation of multiple shear bands, and ultimately lead to a significant improvement in impact absorption energy. This study provides a new approach for improved dynamic mechanical properties of BMGCs.