Deformation modes in NbAl3

The DO₂₂ lattice of the NbAl₃ intermetallic compound shows very limited ductility at room temperature. In this study the slip and twinning systems that are active during the deformation process were investigated. Evaluation of the possible deformation modes was performed and contrast analysis in the transmission electron microscope revealed both expected and unexpected deformation modes. Two types of dislocations were found in the deformed structure, namely thea 〈110〉 superdislocation on the {112} plane and loops of unidentified dislocations on the {010} plane. No evidence of 〈201〉 superdislocations was found, probably due to the fact that this type of dislocation is expected to move in groups of four. Twins of the {112} type were found to play an important role in the deformation process since they supply a component of shear perpendicular to the (001) plane.