Structural heterogeneity governing deformability of metallic glass

Deformability of metallic glasses (MGs) is strongly influenced by their thermomechanical processing history that governs their en-ergy state and local atomic configurations. Here, we reveal that monatomic tantalum MG nanowires, tailored by electropulsing, can attain a remarkable range of deformability, manifesting as either liquid-like flow or brittle fracture. Inherent structural hetero-geneity on the level of atomic order dominates the plasticity and deformation transition of monatomic MGs. By tracking atomic rear-rangement during straining, we find the dispersive and sparse distri-bution of local order is associated with necking, yet percolation of medium-range order constrains the deformability and results in brittle failure. This work sheds new light on the structure-property relationships in MGs, which has important implications for the design of nanoscale MGs with tunable mechanical properties.

Automated summary

Monatomic tantalum metallic glass nanowires, tailored by electropulsing, exhibit a wide range of deformability, either as liquid-like flow or brittle fracture. The plasticity and deformation transition of monatomic metallic glasses are dominated by inherent structural heterogeneity on the atomic level. The dispersive and sparse distribution of local order is associated with necking, while the percolation of medium-range order constrains the deformability and results in brittle failure. This work provides insights into the structure-property relationships in metallic glasses and has implications for the design of nanoscale metallic glasses with tunable mechanical properties.