Four-layer defects in quenched aluminium

Abstract

Abstract The form of vacancy clusters in quenched aluminium of 99.99% purity has been investigated using transmission electron microscopy techniques. A new four-layer planar vacancy cluster lying on parallel {111} planes has been observed and its structure has been characterized by observing both the unfaulting behaviour of the defect and the electron contrast behaviour of its component dislocations. It is argued that this defect is heterogeneously nucleated.