MICROSTRUCTURAL EVOLUTION AND MECHANICAL-PROPERTIES OF SIC/AL2O3 PARTICULATE-REINFORCED SPRAY-DEPOSITED METAL-MATRIX COMPOSITES

In this study, aluminium-copper-based metal-matrix composites were synthesized utilizing the spray atomization and co-deposition technique. Microstructural characterization studies were carried out with an emphasis on understanding the effects associated with the co-injection of silicon carbide and aluminium oxide particulates. The results demonstrate the ageing kinetics of the spray-deposited and hot-extruded metal-matrix composites to be the same as those of the monolithic aluminium-copper material. Results of ambient temperature mechanical tests demonstrate that the presence of particulate reinforcement in the metal matrix does little to improve strength, and degrades the ductility of the matrix material. A model is formulated to compute the critical volume fraction of reinforcement. The results obtained using this model suggest that an optimum volume fraction of silicon carbide is essential in order to realize a strength improvement in the metal-matrix composite, relative to their monolithic counterpart.