Recently, the research team led by Prof. Jiang Jianzhong from the School of Advanced Materials and New Energy, Fuyao University of Science and Technology, published a research paper entitled Anomalous temperature dependence of elastic limit in metallic glasses in the renowned international journal Nature Communications. Using molecular dynamics (MD) simulations and the high-throughput nudge-elastic band (NEB) method, this study investigated the relationship between the kinetics of shear transformation (ST) events and the deformation of metallic glasses at finite temperatures, providing a new perspective for understanding the plastic yielding of metallic glasses.

Based on the Nudge-Elastic Band (NEB) method, the research constructed energy-strain landscapes to quantitatively analyze the effects of temperature and strain on shear transformation events and their activation energies. It was found that the elastic limit of metallic glasses at ultra-low temperatures and its temperature dependence are determined not only by the strain at which shear transformations occur at that temperature, but also by whether the shear transformation events are reversible at the given temperature. A deformation mechanism was proposed, in which shear transformations evolve from irreversible to reversible via thermal activation as temperature rises, accounting for the anomalous increase in the elastic limit of metallic glasses with increasing temperature.

Using MD simulations, the team studied the ultra-low-temperature mechanical behavior of Cu₆₄.₅Zr₃₅.₅ metallic glass samples and discovered the anomalous temperature dependence of the elastic limit in the ultra-low-temperature regime. Shear transformation events during deformation were analyzed using potential energy-strain landscapes and microstructural characterizations. Strain-dependent potential energy diagrams were established to reveal the mechanism underlying the anomalous elastic limit, enabling a systematic understanding of the yielding mechanical behavior of metallic glasses at ultra-low temperatures.

Paper link: https://doi.org/10.1038/s41467-023-44048-7