A microstructural analysis of Al-rich γ-TiAl deformed by 〈0 1 1] dislocations

A transmission electron microscope investigation of the conditions of locking of 〈0 1 1] dislocations and related deformation debris is conducted in Al-rich γ-TiAl (L10 ordered structure) deformed in a temperature range relevant to the yield stress anomaly (YSA). Observations are paralleled with results previously obtained in L12 compounds (e.g. Ni3Al-based alloys) where a YSA occurs within a comparable range of deformation temperatures, involving an analogous type of dislocation with comparable dissociation modes and similar locking abilities. It is shown that in spite of differences in dislocation fine structure, the two systems to belong to the same class of YSA.