Mg–Cu–Y–Ag bulk metallic glasses with enhanced compressive strength and plasticity

Novel Mg–Cu–Y–Ag bulk metallic glasses (BMGs) were prepared by water cooled copper mold casting. The compressive test shows that, by partial substitution of Mg with Ag, the compressive fracture stress, plastic strain, and Young's modulus of Mg58Cu25Y10Ag7 BMG alloy reach 1330 MPa, ∼0.2% and 74.8 GPa, respectively. The compressive strength of this BMG is the highest among those of Mg-based BMGs and crystalline alloys reported to date. Fine vein patterns and dimples are observed on the fracture surface of these BMGs. It is suggested that the improvement in the mechanical properties of Mg–Cu–Y–Ag BMG alloys is mainly attributed to the high moduli and Poisson's ratio of Ag.