Computer simulation of dislocation cores in h.c.p. metals I. Interatomic potentials and stacking-fault stability

Abstract

Four pair-wise potentials have been found to be suitable for the simulation by computer of stacking faults and dislocation core configurations in model crystals having the hexagonal-close-packed structure. The potentials define stress-free perfect crystals and have markedly different ranges and shapes, but the crystals have very similar elastic properties. The stability of translational stacking faults on basal and non-basal planes has been investigated, and it is concluded that stable faults can exist on all the planes considered. The translation vectors and volume expansions associated with the faults are reasonably well understood in terms of the hard-sphere model of the structure, irrespective of the form of the potential, and changes in atom coordination at the non-basal faults may be used to estimate the fault energy. The potentials are used in parts II and III to investigate dislocation behaviour.