Thermo-mechanical study of bulk glass forming Zr-Cu-Ni-Al alloys

• Higher GFA was found for Zr69Cu12·5Ni11Al7.5 compared to Zr68Cu13Ni11·5Al7.5 alloy.
• Quasicrystals formation was found in bulk glass forming Zr68Cu13Ni11·5Al7.5 alloy.
• Lower specific heat was measured in the undercooled liquid for Zr69Cu12·5Ni11Al7.5.

The thermal stability and viscous flow behavior of bulk glass forming Zr68Cu13Ni11·5Al7.5 and Zr69Cu12·5Ni11Al7.5 alloys are studied. The viscosity experimental results are interpreted based on the free volume model (FVM). The values of the obtained model parameters are used to estimate the glass forming ability (GFA) in terms of Angell parameter, and the fracture strength of the alloys based on its correlation with the glass transition temperature (Tg). The viscosity data are compared with DSC measurements. The two glasses, having similar composition, revealed comparable Tg, but one of them (Zr68Cu13Ni11·5Al7.5) showed substantially lower crystallization temperature due to quasicrystals formation. Higher GFA was obtained for Zr69Cu12·5Ni11Al7.5 alloy.