ABSTRACT

Using quasicontinuum method (QCM), we study GB migration in the dissociated edge dislocation interacting with a Sigma 11 symmetrical tilt grain boundary (STGB) upon the mixed-mode of simple shear and tensile loadings. The interaction mechanisms are analyzed with the aid of Burgers vectors conservation equations. It is found that loading state significantly impacts not only the dislocation transmission but also the nucleation of grain boundary dislocations (GBDs). Under mixed loading, GBD dipole nucleation tends to easily occur in comparison to the pure shearing even when some incoming dislocations impinging on GB. Besides, mixed loading could reduce the normal stress resolved on the out-going slip plane in the neighboring grain, which makes the dislocation transmission easier in comparison with the pure shearing loading. Further, a map of the critical shear and normal stresses resolved on the grain boundary (GB) plane at the dislocation-GB interaction site is given to identify dislocation transmission, nucleation of GBD and GBD dipole for the different loading states and the cases of different number of incoming dislocations.