Prediction of good glass formers in the Al-Ni-La and Al-Ni-Gd systems using topological instability and electronegativity

Abstract

A new criterion has been recently proposed combining the topological instability (λ criterion) and the average electronegativity difference (Δe) among the elements of an alloy to predict and select new glass-forming compositions. In the present work, this criterion (λ.Δe) is applied to the Al-Ni-La and Al-Ni-Gd ternary systems and its predictability is validated using literature data for both systems and additionally, using own experimental data for the Al-La-Ni system. The compositions with a high λ.Δe value found in each ternary system exhibit a very good correlation with the glass-forming ability of different alloys as indicated by their supercooled liquid regions (ΔTx) and their critical casting thicknesses. In the case of the Al-La-Ni system, the alloy with the largest λ.Δe value, La56Al26.5Ni17.5, exhibits the highest glass-forming ability verified for this system. Therefore, the combined λ.Δe criterion is a simple and efficient tool to select new glass-forming compositions in Al-Ni-RE systems.