抄録
Fine regular structures are occasionally visible in the grain boundary of an annealed Fe–Mn alloy when observed in a high-voltage electron microscope. They are in the form of either an array of dislocations or serrations in the grain boundary. The orientation relationship between the neighboring grains was near one of the coincidence relationships and the grain boundary plane corresponded to one of the densely packed planes of the coincidence site. The structure and possible behavior of such dislocation array in the coincidence boundary were considered theoretically.
It was concluded that the Burgers vector of the boundary dislocation makes up a three-dimensional lattice which depends on the coincidence system but is independent of the boundary plane orientation. Each boundary dislocation is generally bound to a step in the grain boundary whose height depends on the boundary plane on which the dislocation is located. The Burgers vectors of lattice dislocation form superlattice with the Burges vectors of the grain boundary dislocation. Therefore, a lattice dislocation on arriving at the grain boundary disintegrates into grain boundary dislocations if the temperature is high and grain boundary diffusion is active. The Burgers vector of some of the grain boundary dislocations are parallel to the coincidence grain boundary. However, the Peierls stress for the gliding of the boundary dislocation appears to be generally high.
