Transmission electron microscope studies of point defect clusters in fcc and bcc metals

Reviews the contribution that transmission electron microscopy has made to the understanding of the mobility and clustering of point defects in fcc and bcc metals. The first part of the paper considers the nucleation and growth of vacancy clusters in quenched fcc metals. In the second part the complex subject of irradiation damage is discussed with emphasis being placed on showing the inter-relationship existing between basic damage processes governing defect production and the visible defect structure. The third section discusses the observation of cluster growth and shrinkage in terms of the information they provide about defect mobility. In the final part of the paper a summary is presented of the main conclusions that can be drawn from electron microscope studies regarding the behaviour of vacancy and interstitial defects in fcc and bcc metals.