Tension-compression asymmetry of grain-boundary sliding: A molecular dynamics study

摘要

? 2022 Elsevier B.V.The underlying mechanisms of the tension–compression asymmetry of grain boundary (GB) sliding are studied by molecular dynamics (MD) simulations. The results show that the compressive stress has a suppression effect on GB sliding, while the tensile stress has a promotion effect. The pressure-dependent behaviors of GB sliding are attributed to two aspects. The first one is the tension–compression asymmetry of local shear events in GBs, which is similar to shear banding in metallic glasses. The other is due to a novel strengthening mechanism of compression-induced GB bending, which increases the plastic flow stress.