Effect of additional elements on the thermal stability of the Cu-Zr glassy alloys

The Cu-Zr binary alloys are known to have a high glass forming ability. Inoue et al. reported that the melt-spun CuxZr100-x (x=25-75 at%) binary alloys could possess a single amorphous phase with a wide super-cooled liquid region. In this work, we focused on the Cu60Zr40 glassy alloy with an extremely wide super-cooled liquid region, Delta T-x of about 75 K and replaced a part of the alloy with additional elements. We prepared the (Cu0.6Zr0.4)(97)M-3 (M = B, Al, Si, Cr, Fe, Co, Ni, Pd, Ag, Au), (Cu0.6Zr0.4)(94)M-6 (M = B, Al, Si, Cr, Fe, Co, Ni, Ag) and the Cu60Zr35M5 (M= B, Al, Si, Cr, Co, Ni, Zn) glassy alloys by the melt-spinning technique and investigated the thermal stability and the mechanical properties of those ternary alloys. It is found that addition of those elements causes a decrease in Delta T-x and that addition of Al, Si, Cr, or Ni increases the Vickers hardness of the alloy. The glass transition was not observed for the Cu65Zr35Si5 alloy.