Dislocation-dislocation annihilation by cross-slip

Two screw dislocations of opposite sign glide under stress in closely spaced parallel 111 slip planes. When the distance between the two slip planes is smaller than a critical value, a screw dipole is formed or the two screw lines mutually annihilate by cross-slipping into the second slip plane containing their 110 Burgers vector. Cross-slip is a thermally activated core mechanism.