Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : October 25, 2023 - October 27, 2023
To investigate the specificity of Σ15 grain boundaries in hetero-nanostructured Ti as a source of deformation modes of basal slip and {1121} twin, we perform tensile deformation simulations of a polycrystalline model containing random grain boundaries through molecular dynamics simulations. As a result, the following were found. (1) The basal dislocations are not activated even if it reached the CRSS of Σ15, but the prism dislocations are emitted from random grain boundaries preferentially. This suggests that Σ15 acts as an effective source of the basal dislocation. (2) The CRSS of the prism slip system emitted from Σ15 is much larger than the CRSS for random grain boundaries. This indicates that Σ15 is a difficult interface for prism dislocations to be activated. (3) The CRSS of {1011} twin activated at random grain boundaries was lower than the RSS of {1011} twin at Σ15. This indicates that Σ15 is a difficult interface for {1011} twin to be activated. In other words, it was recognized that {1121} twin was activated in Σ15 because {1121} twin reached the CRSS before {1011} twin.
