THE IMPORTANCE OF NONCOMPACT SLIP IN SOME CLOSE-PACKED METALLIC STRUCTURES

The microscopic mechanisms associated with non-compact slip in hexagon al close packed metals, face centered cubic metals and ordered interme tallics are described. Informations are obtained from in-situ strainin g experiments in the electron microscope as well as macroscopic deform ation tests on magnesium, beryllium, aluminium, copper and Ni3Al. Disl ocation motion on non-compact planes occurs through various cross slip processes for screws. In some cases edge dislocations are slower than screws. The role of non-compact slip in high temperature deformation is discussed.