HRTEM investigation of dislocation interactions in WC
Résumé
The defect structure of the carbide phase in WC-Co alloys is studied by high resolution transmission electron microscopy. 1/3 < 1-213 > dislocations dissociated into 1/6 < 1-213 > partial dislocations in the {10-10} prismatic plane are studied and the atomic structure of the associated stacking fault is characterized. Another type of prismatic fault bounded by 1/2 < 10-11 > partial dislocations is also analysed. Interactions of extended dislocations are often observed and lead to the formation of dipoles when the dissociation occurs in parallel prismatic planes, or to 1/6 < 11-20 > stair-rod dislocations when the dissociation takes place in intersecting prismatic planes. The reaction of 1/6 < 1-213 > partial dislocations leads to sessile defects that are expected to limit the plasticity of the WC phase even at high temperature. (C) 2013 Published by Elsevier Ltd.