Theoretical latent hardening of crystals in double slip—I. F.C.C. crystals with a common slip plane

The hardening of all slip systems in f.c.c. crystals, deforming in finite double-slip on two systems with a common slip plane, is determined according to the “simple theory” of rotation-dependent plastic anisotropy. Both tensile and compressive axial-loading are considered. Of particular interest are predictions of crystal response after the loading axis has rotated into a higher symmetry position (6-fold in tension and 4-fold in compression). In contrast with classical Taylor hardening, the simple theory predicts that the axis will “overshoot” the higher symmetry position. A postulate of minimum plastic work plays a significant role in the theoretical analyses of multiple-slip positions.