Structural and mechanical characterizations of ductile Fe particles-reinforced Mg-based bulk metallic glass composites

In this study, the atomic composition of Mg₅₈Cu_28.5Gd₁₁Ag_2.5 which possess high glass forming ability (GFA) was selected as the matrix alloy for synthesizing the ductile Fe particles-reinforced Mg-based bulk metallic glass composites (BMGCs) by using injection casting method. The results show that the compressive ductility increases with the volume fraction of Fe particles and reaches up to the compressive plastic strain of 8% for the Mg-based BMGC with 20 vol.% Fe. In parallel, multiple-shear bands were revealed on the sample surface which is near the fracture area. This suggests that these Fe particles can branch primary shear band into multiple-shear bands and decrease the stress concentration for further propagation of shear band, and so as to enhance plasticity. Additionally, a slightly decreasing in yield strength with increasing the addition of Fe particles was found presumably due to the formation of brittle Fe₂Gd intermetallic phase at the interface between the Fe particle and amorphous matrix. In overall, the ductile Fe dispersoids would provide a good toughening effect in promoting the practical use of amorphous materials.