Interaction of Dislocations with an Applied Stress in Anisotropic Crystals

The equilibrium shape of a dislocation segment between two pinning points in the same glide plane is calculated. The assumption is made that the dependence of the dislocation self-energy on the geometry of the dislocation line can be expressed by using an energy per unit length, $E$, which is a function only of the angle, $\theta$, between the Burgers vector and the tangent to the dislocation. Only glide of the dislocation, not climb, is considered. The results obtained are compared with those for elastically isotropic crystals. It is found that the character of the dislocation shape is altered considerably if $E+\frac{d^{2}E}{d{\theta }^2}$ can be negative. It is suggested that the change in sign of this quantity is associated with diffusionless phase changes.