Passing dislocations in f.c.c. alloys and related superlattices

Abstract

A detailed numerical analysis has been made of the equilibrium configurations associated with extended passing screw dislocations of opposite signs on parallel planes in a disordered (f.c.c.) and ordered alloy (Cu₃Au type). Both the shear stresses required to move these configurations past one another as well as the cross-slip stresses exerted by one on the other have been calculated. It is shown that ordering increases both the passing and cross-slip stresses. This is related for the most part to the increased degree of coalescence in the extended partials brought about by atomic ordering.