Computational thermodynamics to identify Zr–Ti–Ni–Cu–Al alloys with high glass-forming ability

Abstract We have used a thermodynamic computational approach to identify the compositions of Zr–Ti–Ni–Cu–Al alloys exhibiting low-lying liquidus surfaces, which tend to favor the formation of bulk metallic glasses. Guided by these calculations, we have identified several series of new Zr-based alloys with excellent glass formability, some of which can be cast into glassy rods up to 14 mm in diameter. These alloys exhibit wide undercooled liquid regions ( T x − T g ) up to 85 K and high Vickers hardness from 550 to 700 kg/mm 2 . The best glass-forming alloy is Zr 51 Ti 5 Ni 10 Cu 25 Al 9 . The computational thermodynamic approach coupled with the reduced glass transition temperature criterion of Turnbull can rapidly identify regions of alloy composition suitable for experimental tests for glass formation. The glass-forming ability of the alloys we studied can be understood in terms of the relative liquidus temperature in a thermodynamically calculated temperature vs. composition section through a multicomponent phase diagram. It does not follow several other proposed thermodynamic or topological criteria. Our general approach may be extended into a universal tool to identify alloys with good potential to form bulk glasses.