The interface region in squeeze-infiltrated composites containing δ-alumina fibre in an aluminium matrix

The nature of the interfaces formed between fine, delta -alumina fibers and Al-based matrices is examined. Alloys containing Mg and Si and high-purity Al have been employed. The fabrication process involved high-pressure melt infiltration of a fibrous preform. It has been found that no detectable interfacial reaction product is formed in these systems, although there is in some cases evidence of a limited exchange of Mg between melt and fiber surface. It is concluded, both from measurements and from process analysis, that any distinct chemical reaction product formed at the interface between fiber and matrix must be limited in extent to the atomic monolayer level. 29 ref.--AA(UK/US).