Dislocations in the primary slip systems of face-centered cubic crystals

Abstract

Application is made of the anisotropic elastic analysis 1,2 of uniformly moving dislocations to study the dynamical behavior of dislocations in the primary slip systems of f.c.c. crystals. Both edge and screw dislocations in the 〈112〉 and 〈110〉 orientations on the {111} plane are considered in detail. For various f.c.c. elements, numerical solutions are obtained for the force between two parallel dislocations as a function of velocity. Calculated values are presented of: 1. (1) the threshold velocity at which the force vanishes, and 2. (2) the limiting velocities of both edge and screw dislocations. These calculations determine the extent of the velocity range of anomalous behavior for the different dislocation interactions. Since the dislocations of interest usually exist as two partial dislocations separated by a stacking fault, numerical solutions are also obtained for the force between the two partials as a function of velocity for both extended edge and screw dislocations. In addition to the calculations for the f.c.c. elements, similar calculations are also made for a series of fictional f.c.c. materials. As a result, a number of correlations are obtained between elastic constant values and dynamical behavior.