Planar dissociations of [101-bar] superdislocations in TiAl: ab-initio electron theory and generalized Peierls-Nabarro model

摘要

The planar configuration of the [101-bar] superdislocation in stoichiometric TiAl is determined with the generalized Peierls-Nabarro model using the γ-surface energies calculated by the ab-initio electron theory. The displacement field is parametrized by a superposition of four partial Peierls dislocations. From the calculated separations of the partials it is concluded that a weak-beam image of the [101-bar] superdislocation should resolve a superlattice intrinsic stacking-fault ribbon, whereas the complex stacking-fault (antiphase-boundary) ribbon is at (beyond) the limit of the resolution.