Dispersion toughening of Mg-based bulk metallic glass reinforced with porous Mo particles

We have successfully synthesized the porous Mo particles reinforced Mg₅₈Cu_28.5Gd₁₁Ag_2.5 metallic glass composites (BMGCs) rods with a diameter of 2∼6 mm by injection casting in an Ar atmosphere. The glass forming ability and mechanical properties of such Mg-based BMGCs are systematically investigated as a function of porous Mo volume fraction and injection-cast cooling rate. The results show that superior mechanical performance with up to 14% compressive failure strain, 1050 MPa yield strength and 1200 MPa fracture strength at room temperature can be obtained for the Mg-based BMGC with 25 vol% Mo particles. The dispersed porous Mo particles act as a network in the amorphous matrix, which restricts the highly localized shear banding into many isolated micro-scaled regions, avoiding complete shear-through of one principal shear band across the whole sample. This results in the formation of multiple shear bands within or around the porous Mo particles and the decrease of stress concentration for further propagation of shear band, enhancing the plasticity. Moreover, the yield strength and plastic strain exhibit an increasing trend with increasing cast cooling rate, due to lower residual porosity.