Predicting glass-forming compositions in the Al–La and Al–La–Ni systems

In this work, a criterion considering the topological instability (λ) and the differences in the electronegativity of the constituent elements (Δe) was applied to the Al–La and Al–Ni–La systems in order to predict the best glass-forming compositions. The results were compared with literature data and with our own experimental data for the Al–La–Ni system. The alloy described in the literature as the best glass former in the Al–La system is located near the point with local maximum for the λ·Δe criterion. A good agreement was found between the predictions of the λ·Δe criterion and literature data in the Al–La–Ni system, with the region of the best glass-forming ability (GFA) and largest supercooled liquid region (ΔTx) coinciding with the best compositional region for amorphization indicated by the λ·Δe criterion. Four new glassy compositions were found in the Al–La–Ni system, with the best predicted composition presenting the best glass-forming ability observed so far for this system. Although the λ·Δe criterion needs further refinements for completely describe the glass-forming ability in the Al–La and Al–La–Ni systems, the results demonstrated that this criterion is a good tool to predict new glass-forming compositions.

Research highlights▶ The glass-forming ability of the Al–La and Al–La–Ni systems was studied using the λ* and the λ·Δe criteria. ▶ Both criteria predicted with just 1% at. of error the best glass-former verified so far in the Al–La system. ▶ Four new glass-former compositions could be predicted in the Al–La–Ni system using the λ·Δe criterion. ▶ The best glass-former reported so far in the Al–La–Ni system was found.