Short-to-medium range structure and glass-forming ability in metallic glasses

In this paper, we investigate the clustering model and glass-forming ability (GFA) in response to variant compositions and cooling rates. The structural units are obtained by molecular dynamics and hierarchical clustering. In the clustering model, a nesting relationship from small- to large-scale units, i.e., from short- to medium-range order, is observed during the hierarchical clustering. Furthermore, the packing efficiency of short-range units is applied to depict the GFA, and the result suggests that the packing efficiency is not strictly increased with respect to cooling rate. A positive correlation between a high packing efficiency and a large skewness is found, which validates that alloys with the stronger GFA have a more disordered structure.