Multiscale computational and experimental analysis of slip-GB reactions: In situ high-resolution electron backscattered diffraction and concurrent atomistic-continuum simulations

In this paper, in situ high-resolution electron backscattered diffraction (EBSD) is combined with concurrent atomistic-continuum (CAC) simulations to study the interactions between dislocation-mediated slip and grain boundaries (GBs) in Ni. It is found that the local stress associated with slip-GB intersections first increases upon the pileup of dislocations, then remains high even after the nucleation of dislocations in the neighboring grain, only relaxing after the nucleated dislocations propagate away from the GB due to more incoming dislocations participating in the pileup. The local stress relaxation is accompanied by an atomic-scale GB structure reconfi-guration, which affects not only the subsequent dislocation transmission, but also the configuration of those dislocations away from the GB. These findings demonstrate the importance of incorporating local stress history at higher length scale models, such as crystal plasticity finite element.

Automated summary

This paper combines in situ high-resolution electron backscattered diffraction (EBSD) with concurrent atomistic-continuum (CAC) simulations to investigate the interactions between dislocation-mediated slip and grain boundaries (GBs) in Ni. The study shows that the local stress at slip-GB intersections initially increases with the pileup of dislocations and remains high, even after the nucleation of dislocations in the neighboring grain. The local stress only relaxes when the nucleated dislocations propagate away from the GB due to more incoming dislocations participating in the pileup. The relaxation of local stress is accompanied by the reconfiguration of atomic-scale GB structure, which not only affects subsequent dislocation transmission but also the configuration of dislocations away from the GB. These findings highlight the importance of incorporating local stress history in higher length scale models, such as crystal plasticity finite element.