Uniformly Moving Dislocations of Arbitrary Orientation in Anisotropic Media

The dynamical behavior of uniformly moving dislocations in anisotropic media is considered for the general case in which the dislocation involves three components of displacement. It is found that both edge and screw dislocations can display an anomalous behavior. It appears that, in general, the force of interaction between two parallel dislocations on the same slip plane changes sign with increasing dislocation velocity; this result obtains whether the dislocations involved be two edges, two screws, or an edge and a screw. The threshold velocity at which the force of interaction changes sign is a function of the orientation and type of dislocation. However, the limiting velocity, at which the energy of the dislocation becomes infinite, is a function only of the orientation of the dislocation and is the same whether the dislocation be pure edge, pure screw, or mixed in character. Numerical results are presented for ($\overline{1}10$) [$11\overline{1}$] dislocation motion in lithium.