Alloying effects on mechanical properties of the Cu-Zr-Al bulk metallic glass composites

Recently, bulk metallic glass (BMG) composites reinforcing with an austenite primary phase have shown much improved mechanical properties under tensile loading due to the transformation-induced plasticity. In this paper, alloying effects of the transitional metals on the mechanical properties of a CuZr-based BMG composite were studied both experimentally and theoretically. It was found that additions of certain elements such as Co and Ni could greatly enhance the mechanic performance of the BMG composite. Experimental results, coupled with first-principle calculations, suggest that such alloying atoms could effectively reduce the generalized stacking fault energy of B2-CuZr due to the less charge density redistribution during the stack fault formation and thus promoted the martensitic transformation, eventually giving rise to the improved mechanical properties.