The motion of edge dislocations and kinked edge dislocations in body-centered cubic Fe were studied at atom level. The kink-pair nucleation mechanism was found directly from the configurational evolution of dislocations: the edge dislocations moved primarily via the kink-pair nucleation, and the pre-existing kink did not affect this mode of motion. The result was in agreement with the energy calculation. Furthermore, the Peierls stress, dislocation velocity, and phonon-drag coefficient were considered. There were obviously two motion regions with different stresses. In the low-stress region, the stress exercised a great influence upon the dislocation motion and the dislocation velocity increased significantly with the increase of stress. In the high-stress region, however, phonon drag practice a dominant factor on the dislocation motion, the dislocation move with approximately constant speed close to the transverse speed of sound.

The Kink-Pair Nucleation in Edge Dislocation Motion. S.Yu, C.Y.Wang, T.Yu: Solid State Sciences, 2009, 11[3], 733-9