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The Dissociation of a Screw Superdislocation in the B2 Structure
Author(s) -
Saada G.,
Veyssière P.
Publication year - 1992
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.2221720127
Subject(s) - dihedral angle , metastability , materials science , planar , crystallography , anisotropy , lattice (music) , slip (aerodynamics) , condensed matter physics , chemistry , thermodynamics , physics , optics , hydrogen bond , computer graphics (images) , organic chemistry , molecule , computer science , acoustics
Cross‐slip of a dissociated 〈111〉 screw superdislocation in the absence of an applied stress is studied within the frame of anisotropic elasticity in model B2 crystals. Lattice friction is ignored. The superdislocation can either be coplanar, and then confined to either of the {110} and {112} habit planes, or dihedral. The stability of these configurations is governed by the values of one elasticity parameter named N , by the ratio z between the antiphase boundary (APB) energies on these planes, and by the cross‐slip angle α. The different situations of interest are studied. By contrast to what occurs in L1 2 alloys, it is shown that besides two alternative planar configurations, one may encounter dihedral stable or metastable configurations which add to the variety of possible locking configurations in B2 alloys. The relative stability of these possible locking modes is discussed in details with respect to N and z , for the different cases of cross‐slip.