Plastic Deformation

· When the dislocation loop on the slip plane expands by an amount dx, work is done by the external forces as the region of slipped material increases. This work translates into an effective force per unit length of the dislocation loop given by: F = {(b · Σ) xt}.
· This force is seen to be normal to the line vector, t, and may be resolved into components in the slip plane and normal to the slip plane.

· In the slip plane of the dislocation: F_g= F· g , where g is the unit vector in the slip direction: g = t x (b x t)/ (b x t) .
· Normal to the slip plane: F_n = F · n , where n is the unit vector normal to the slip plane: n = (b x t)/ (b x t)