Twin boundary and grain boundary effects on cyclic responses of tensile pre-deformed highly oriented nanotwinned Cu: Molecular dynamics simulation

摘要

Molecular dynamics method is performed for analyzing the relationship of the twin boundary and grain boundary on the cyclic response of nanotwinned Cu. Results show that the strength difference among the grain boundary, the twin boundary and the variation of dislocation density are nearly 2-2.5 times. We predict twin boundary is only a factor that affects the stable response, however, the dislocation form and the time to reach stability is caused by the grain boundary. Furthermore, the phenomenon of cyclic hardening is found in all the nanotwinned Cu samples. (C) 2020 Elsevier B.V. All rights reserved.