Transmission Electron Microscopy of Interfacial Areas in Metal-Matrix Composites*

Abstract

Microtechniques of selected-area transmission electron microscopy have been developed for the study of interfacial areas in a high- strength aluminum alloy reinforced with stainless-steel wires. The specimen-preparation procedures are described and the conditions necessary for the successful production of useful areas of trans mission progressively nearer the interface in the composite foils are discussed. Dislocation arrangements in the aluminum alloy matrix of a composite subjected to fatigue loading have been ob served as a function of the distance from the filament-matrix interface. The dislocation density was not appreciably affected by the presence of the filament-matrix interface to within 25 microns of the interface. The results demonstrate the potential usefulness of such studies to the development of improved design criteria through a better understanding of the micromechanisms of com posite behavior.