Stress-induced migration of tilt and twist grain boundaries

The reaction of planar -tilt and twist grain boundaries to mechanical stresses is reviewed. It was found that the motion of low-angle grain boundaries as well as of high-angle grain boundaries can be induced by an imposed external mechanical stress field. The migration of grain boundaries was measured in-situ using X-ray diffraction to localize the grain boundary position continuously. From the observed activation enthalpies, conclusions can be reached regarding the migration mechanisms of the stress-induced grain boundary motion. The motion of planar low- and high-angle grain boundaries under the influence of a mechanical stress field can be attributed to the movement of the grain boundary dislocations which comprise the structure of the boundary. A sharp transition between low- and high-angle grain boundaries was observed for tilt as well as for twist grain boundaries.