Interaction of edge dislocation with point defect clusters created in displacement cascades in α-zirconium

Atomic-scale details of the interaction of a 1 / 3 1   1   2 ¯   0 ( 0   0   0   1 ) edge dislocation, which dissociates in the basal plane, with four typical vacancy and self-interstitial atom (SIA) clusters created by displacement cascades in α-zirconium are investigated by computer modelling. A triangular cluster of SIAs lying within a basal atomic plane adjacent to the dislocation glide plane is not absorbed by the dislocation but is pushed along by the leading partial. A 3-D SIA cluster lying across the glide plane is completely absorbed by the dislocation by creation of two super-jogs. The dislocation also climbs by interaction with a prismatic vacancy cluster, but only half of the vacancies are absorbed in this case. For a cluster formed from a basal platelet of vacancies, the dislocation experiences a glide resistance, but both the line and cluster are fully restored after breakaway. Stress–strain curves and the critical stress for dislocation breakaway from a cluster are presented.