Defect, surface and displacement-threshold properties of α-zirconium simulated with a many-body potential

Abstract

A many-body interatomic potential has been developed for the h.c.p. metal α-zirconium using the same methodology as that used by Ackland for α-titanium. The repulsive pair part of the potential has been constructed so that the model can be employed for simulating atomic collisions. The favoured self-interstitial configurations are the 〈1120〉 crowdion and split defects, and they are highly mobile in the basal plane. The energy of surfaces is not strongly dependent on the crystallographic orientation, and the I₂ stacking fault on the basal plane is not stable. The displacement threshold energy in a crystal at 0 K exhibits a similar orientation dependence to that computed recently for α-titanium by Bacon et al. and has the same minimum of 27·5 eV along the 〈1120〉 directions, but the mean value of 55 eV averaged over all orientations is higher than that of 30 eV in titanium.