Dislocation-assisted diffusion-mediated atomic reshuffling in the Kolbe mechanism for micro-twinning in Ni-based superalloys from molecular dynamics simulation

Micro-twinning is one of the dominant creep deformation mechanisms in Ni-based superalloys at intermediate temperatures. The Kolbe micro-twinning mechanism, based on thermally activated reordering, has been confirmed experimentally and analyzed theoretically. However, many aspects of the reordering process are still under debate. This work presents the first molecular dynamics (MD) simulation study of the Kolbe mechanism. We demonstrate that atomic diffusion-mediated reordering takes place in the immediate vicinity of the cores of twinning partials and proceeds in a highly concerted manner, directly influenced by propagation of the dislocations.

Automated summary

This study presents the first molecular dynamics simulation of the Kolbe mechanism, revealing that atomic diffusion-mediated reordering occurs in a highly concerted manner, directly influenced by the propagation of dislocations.