Computer simulation of twin boundaries in the h.c.p. metals

Abstract

The energy and atomic structure of {1121}, {1122) and {1012} twin boundaries in the hexagonal-close-packed (h.c.p.) metals have been investigated using computer simulation. Three distinctly different interatomic potential functions have been used in either equilibrium or non-equilibrium form. It is predicted that only one form of boundary can occur for {1121} and {1012} twins, but several interfaces may exist for (1122} twins. The stable boundaries are, with one exception, associated with one or both of the symmetry operations of reflection and 2-fold rotation defined in the conventional theory of twinning. The good agreement between the results for all six model crystals suggests that the structures found here have general relevance to twin boundaries in real h.c.p. metals.