Predict the temperature dependence of the elastic limit in metallic glasses from the energy-strain landscape picture
Date:
2022 Materials Research Socienty Spring Meeting & Exhibition
Abstract
Potential energy landscape (PEL) is considered one of the most promising ways to understand the atomistic mechanisms of inelastic deformations in glassy materials. However, the evolution of the entire PEL under loading strain is still not clear. Here, we use molecular dynamics simulations and high-throughput energy barrier calculations to determine the PEL evolution as a function of strain under finite temperature, presented as the “energy-strain landscape” picture. Based on this new picture, we discover a strain-independent quantity “eigen-barrier” to characterize the reversibility of shear-transformation (ST) events. A model is developed to determine the hysteresis stress-strain loop of individual independent ST events as a function of temperature, thus predicting the temperature dependence of the elastic limit at low temperatures. Contrary to the common expectation that the elastic limit decreases with increasing temperature, we show that the elastic limit can increase with increasing temperature. This finding provides a quantitative description of the strain dependence of the PEL and brings a new perspective to understand the inelasticity properties of glasses.