A modified stir casting method is applied to fabricate Al-Al2O3 micro and nano composites. The method consisted of heat treatment of reinforcement particles, addition of 1wt.% magnesium as the wetting agent, injection of heat treated particles within the melt by inert argon gas and finally stirring the melt. All the processes are performed in a designed furnace and attached equipment. A novel measurement method was presented in this study to quantitatively study the wettability and distribution of the particles in the composite samples. Subsequently effects of various process parameters e.g. heat treatment of reinforcement particles, additive wetting agent, injection process, stirring the melt, weight percentage of Al2O3 particles and Al2O3 particle size (micron and nano size) on the wettability and distribution of particles investigated. The results showed the poor incorporation of Al2O3 particles in the aluminum melt prepared by the common condition while the use of heat treated particles and 1wt.% additive Mg significantly increases the wettability of particles and also injection of particles and the stirring process improved distribution of the Al2O3 particles within the aluminum melt.

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