Effect of particle size on dynamic mechanical behaviors of W particles/Zr-based bulk metallic glass composites

Abstract

The effect of particle size on the dynamic mechanical behavior of W particle /Zr-based bulk metallic glass composites (Wp/BMGCs) was investigated by split Hopkinson pressure bar (SHPB) and finite element method (FEM). The yield strength decreases with the increase of W particles size under quasi-static compression, while the fracture strain increases. The BMGC with 60% Wp shows the highest fracture strain, and the BMG matrix shows a uniform rheological characteristic which is different from the brittle fracture characteristic. Under dynamic compression, the yield strength of the BMGCs does not show obvious strain rate sensitivity, and the dynamic fracture strain is significantly lower than the quasi-static fracture strain. With the increase of the W particles size, the cladding on the BMG matrix weakened, and the fracture mode changed from fragmentation to shear fracture. We consider that the combination of interface debonding and cleavage fracture was the very reason for the changed fracture mode. It is found that the Ansys/LS-DYNA code is able to predict the response of the Wp/BMGCs in the element mesh if special care is taken, and good agreement is in general obtained between the numerical simulations and experimental results.