A review was presented of the role of dislocation cores and planar faults in activating the non-basal deformation modes, <c+a> pyramidal slip and deformation twinning, in

hexagonal close-packed metals and alloys and in D019 intermetallic compounds. Material-specific mechanical behavior arises from a competition between alternate defect structures that determine the deformation modes. The importance of accurate atomistic modeling of these defects was emphasized; going beyond simple interatomic energy models. Recent results from both experiments and theory were summarized by discussing specific examples of Ti and Mg single crystals; Ti-, Zr- and Mg-based alloys; and Ti3Al ordered alloys.

Non-Basal Deformation Modes of HCP Metals and Alloys - Role of Dislocation Source and Mobility. M.H.Yoo, J.R.Morris, K.M.Ho, S.R.Agnew: Metallurgical and Materials Transactions A, 2002, 33[3A], 813-22