Direct observation of grain-boundary dislocations in the FeCo alloy

Abstract

An extensive transmission electron microscopy study has been made of the structure of high and low angle grain boundaries in both ordered and disordered FeCo alloys which were electrochemically thinned from the bulk material. The grain boundaries observed were determined to be of the primary coincidence type and were found to contain numerous secondary grain-boundary dislocations. These secondary dislocations were either of the true grain-boundary types or else crystal lattice dislocations. The secondary grain-boundary dislocations were presumed to arise from the migration of the grain boundaries during grain growth and were frequently found to dissociate into crystal lattice dislocations arranged in the form of low angle boundaries within one of the adjacent grains.