Effect of substitution of Ni for Cu on glass-forming ability and mechanical properties of Mg-Cu-Tb metallic glass alloys

The Mg₆₅Cu_25-xNi_xTb₁₀ (x = 0, 5, 10) bulk amorphous alloy rods with 3 mm diameters were prepared by copper mold casting technique, and the effect of Ni addition on the glass forming ability (GFA) and mechanical properties of Mg₆₅Cu_25-x Ni_xTb₁₀ (x = 0, 5, 10) alloys were studied by to X-ray diffractometry (XRD), differential scanning calorimeter (DSC), compression tests and scanning electron microscopy (SEM). The results show that the glass transition temperature (T_g) of the Mg₆₅Cu_25-x Ni_xTb₁₀ alloys increases slightly whereas the onset temperature of crystallization (T_x), decreases slightly with the increase of Ni content, which results in the decrease of the supercooled liquid region and the glass forming ability. However, an appropriate substitution of Cu by Ni(5%, mole fraction) in Mg₆₅Cu₂₅Tb₁₀ significantly improves the mechanical properties.