Thermal and mechanical properties of Cu60-xZr25Ti15Nix bulk metallic glasses with x=0, 1, 3, 5, 7, 9 and 11 at.%

Abstract

Systematic investigation on thermal and mechanical properties of Cu60-xZr25Ti15Nix bulk metallic glasses with x = 0, 1, 3, 5, 7, 9 and 11 at.% points out that monolithic Cu53Zr25Ti15Ni7 and Cu51Zr25Ti15Ni9 bulk metallic glasses containing optimum Ni content of 7 and 9 at.% are effective to enhance both thermal stability of amorphous structure up to 716 K and plastic strain of 2.4% at room temperature. This indicates that a selection of additional elements such as Ni by considering a mixing enthalpy to the constituent elements is very important to control the thermal stability and plasticity. Moreover, it is believed that the addition of minor Ni can be a trigger to form the chemical heterogeneity upon solidification. Such chemical heterogeneity formed by the selection of the minor elements has a strong influence to cause the oscillation of the shear stress by wavy propagation of the shear bands thus leading the improvement of macroscopic plasticity of the bulk metallic glasses.