STRESS-INDUCED KNITTING OF DISOLACTION NETWORKS WITH 4-FOLD NODES IN AN ALUMINIUM-MAGNESIUM ALLOY

Two-dimensional dislocation networks were studied in an aluminium-magnesium alloy slightly strained at 500°c after liquid quench, looking especially for four-fold nodes. The condition for the stress-induced knitting of networks with four-fold nodes was found to be that the knitting is performed by two different sets of dislocations, one of which has a Burgers vector perpendicular to that of the forest dislocations. Several networks with four-fold nodes were observed which were knitted on symmetrical tilt boundaries consisting of a dislocation forest in a (110) plane. The existence of such networks gives rise to the assumption that at the high temperature in question one knitting dislocation, the Burgers vector of which is perpendicular to that of the forest dislocation, is moving on the (110) plane by glide. © 1969 Taylor & Francis Group, LLC.