Characterising particle–matrix interfacial bonding in particulate Al–TiC MMCs produced by different methods

Abstract

Abstract By measuring the change in elastic modulus with increasing plastic strain, particle–matrix bonding in Al–TiC MMCs has been characterised. Data show that rates of damage accumulation are lowest, damage initiation stresses are highest and hence interfacial bonding is strongest, in cast composites. It is thought that this is due to the attainment of intimate contact between Al and TiC, through the use of a flux that dissolves surface oxides, and the nucleation of solid Al on the particle surfaces. Intimate metal–ceramic contact is not so easily achieved in composites manufactured from metal powders, owing to the presence of oxide films on their surfaces. Increasing the shear stresses present during solid state consolidation processes does, however, improve the particle–matrix interface strength due to more effective break-up of the oxide barrier.