Atomic simulation study on the effect of Y atom and grain boundary on tensile deformation in polycrystalline magnesium alloy

The deformation of polycrystalline magnesium alloy was studied by molecular dynamics simulation. The influencing factors of tensile properties and its deformation mechanism were discussed. It was found that Y atom could inhibit the activation of basal < a > slip and promote the activation of pyramidal < c + a > slip. The crack was formed at the grain boundary with large orientation differences and propagated along the grain boundary. The stress concentration mainly occurred at grain boundaries, and its concentration decreases with the grain size decreasing. The formation of deformation twin was inhibited by small grains. The twin tended to nucleate at grain boundary and grew by absorbing dislocations. It was also found that new twin was preferentially formed near the old twin. (c) 2023 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

The deformation behavior of polycrystalline magnesium alloy was investigated using molecular dynamics simulation. The factors influencing tensile properties and deformation mechanism were discussed. It was observed that the presence of Y atoms inhibited the activation of basal < a > slip and promoted the activation of pyramidal < c + a > slip. Cracks formed along grain boundaries with significant orientation differences and propagated along these boundaries. Stress concentration mainly occurred at grain boundaries, with concentration decreasing as grain size decreased. Formation of deformation twins was suppressed in small grains, whereas twins tended to nucleate at grain boundaries and grew by absorbing dislocations. Additionally, new twins were preferentially formed near existing twins.