Applying a new criterion to predict glass forming alloys in the Zr–Ni–Cu ternary system

Abstract

A new criterion has been recently proposed to predict and select the glass forming ability (GFA) of metallic alloys. It was found that the critical cooling rate for glass formation (Rc) correlates well with a proper combination of two factors, the minimum topological instability (λmin) and the thermodynamic parameter (Δh). The (λmin) criterion is based on the concept of topological instability of stable crystalline structures and (Δh) depends on the average work function difference (Δϕ) and the average electron density difference Δnws1/3 among the constituent elements of the alloy. In the present work, the selection criterion was applied in the Zr–Ni–Cu system and its predictability was analyzed experimentally. Ribbon-shaped and splat-shaped samples were produced by melt-spinning and splat-cooling techniques respectively. The crystallization content and behavior were analyzed by X-ray diffraction (XRD) and differential scanning calorimetry (DSC), respectively. The results showed a good correlation between the theoretical GFA values and the amorphous phase percentages found in different alloy compositions.