Abstract
Polycrystalline Ni3Al with nominal composition 75 at.% Ni–25 at.% Al has been subjected to creep at 580°C under uniaxial compression and the dislocation structure examined by transmission electron microscopy. A superdislocation interaction between the two screw superpartial pairs with perpendicular Burgers vectors, [101] and [101], but which share a common dissociation plane (010), leads to the formation of a node. Subsequently, superdislocation networks, which consist of an array of nodes on (010), form. A possible mechanism for the node formation is discussed. The equilibrium shape of the superdislocation network has been estimated.