Large-angle grain-boundary structures in hexagonal close-packed metals

Abstract

We present a set of observations of large-angle grain-boundary structures in zinc, obtained by transmission electron microscopy. The necessary formalisms for relating experimental observations to theoretical predictions of the boundary structures are given. Dislocation structures are observed in several boundaries, indicating a ‘crystalline’ character. The structures can be related, in most cases, to coincident site lattices formed either by simple rotations of the crystals or by combinations of rotation and constraint of the c/a ratio to some special value. The Burgers vectors of the dislocations are found to be DSC vectors, and good agreement is obtained between the observed and calculated dislocation array structures.