ABSTRACT
An investigation has been carried out into the formation of the spinel MgAl2O4 phase on the surface of fibres in aluminium alloy MMCs. Interface analysis was performed by a FEGSTEM using a windowless EDS detector and PEELS. It was found that the MgAl2O4 phase was formed initially during the casting process by a reaction between the oxygen within the air spaces of the preform and the alloy. The SiO2 binder was not reduced during casting nor during cooling even though diffusion of magnesium and aluminium atoms has been reported to occur.
