http://www.sciencedirect.com/science/article/pii/S1359645414003097
Activation of non-basal slip systems can be achieved either by solute addition, high-temperature processes, grain refinement, or by hydrostatic pressure. Conceptually, adding <a> dislocations even in the pyramidal slip plane would not enable accommodation of the strains along the c-axis. Therefore, type I and type II <a+c> dislocations have immense importance in order to obtain five independent deformation modes that can fulfill the von Misses criterion for a general homogeneous plastic deformation. Thus the role of pyramidal slip systems in Mg generalized plasticity, and accordingly the alloy design and process design strategies, are of great industrial importance.