Nowadays, technological and industrial advancement is highly dependent on introduction of new materials with special properties. Production of composite materials had been a major step in development and optimization of materials. Aluminum matrix composites due to unique properties such as high strength to weight ratio, good ductility, high corrosion resistance, good thermal and electrical conductivity are the most commonly used metal matrix composites. There are different methods for producing composites, among which liquid state methods are more practical. Mechanical properties of composites depends on the distribution of particles, particle size and shape, wettability and casting defects. In this study, aluminum matrix nano-composite reinforced with silicon oxy-carbide particles was manufactured by in-situ stir casting. A mixture of organic silanes, TEOS and PDMS, at a weight ratio of 40/60 was used to synthesize ceramic particles. Sol-gel method, followed by pyrolysis at different temperatures was employed to complete ceramic particles manufacturing. The results of Fourier Transform Infrared Spectroscopy test of the particles revealed Si-O-Si and Si-C bonds. The product was a nanopowder according to the results of microscopic studies as well as measurements of specific surface area. For further investigation a mixture of pure aluminum powder and silicon oxy carbide were heated at 800°C for an hour in argon atmosphere. X-ray diffraction analysis indicated presence of aluminum oxide, silicon carbide and some aluminum.In order to manufacture aluminum matrix composite, 1 and 3 wt% silicon-oxy-carbide nanoparticles were added to a vortex of molten aluminum. The resultant slurries were poured at 800 and 900°C.The results of the microstructure and mechanical properties investigations of the composites showed improvements of yield strength and hardness up to 46.5% and 5.9% respectively. Nevertheless addition of more silicon oxy-carbide nanoparticles adversely affects mechanical properties because of increasing porosity as well as agglomeration of the particles. Keywords: Cast composite, aluminium matrix, insitu, pyrolysis, reinforcement
