Atomistic insights into strain localization at basal twist grain boundaries in hexagonal close-packed metals

The generalized stacking fault energy as well as the grain boundary energy of basal twist grain boundaries of Ti, Mg, Zr HCP metals are calculated by means of density functional theory in coincident site lattice boundaries. It was found that the generalized stacking fault energy of these boundaries is very low (< 10 mJ/m 2 ) for various twist angles. Thus, localization of plastic deformation by shearing of basal twist grain boundaries is likely to happen in HCP metals which present high values of the critical resolved shear stress for basal slip (such as Ti and Zr). • The generalized stacking fault energy of basal twist grain boundaries of Ti, Mg, Zr hexagonal close-packed metals is calculated in coincident site lattice boundaries. • The generalized stacking fault energy of these boundaries is very low (< 10 mJ/m2) and independent of the twist angle and of the coincident site lattice index Σ. • Thus, localization of plastic deformation by shearing of basal twist grain boundaries is likely to happen in hexagonal close-packed metals which present high values of the critical resolved shear stress for basal slip (such as Ti and Zr).