Effect of Graphite Addition on the Mechanical Properties of Stir cast Particulate Aluminum Metal Matrix Composite Reinforced with Alumina and silicon Carbide

Fabrication of PAMC by stir casting, at semisolid stage of the matrix results in homogeneous distribution of the reinforcements in the matrix, which leads to better mechanical and tribological property of the composite. In present study aluminum alloy Al6082 was reinforced with 1% Al2O3 and 3% SiC and 0 to 6% graphite particles by weight. We have varied temperature, speed of agitation and kept all other parameters constant. With present stir casting process, we have successfully processed the total reinforcement up to15% by weight. PAMC has shown 23% increase in hardness, 110% increase in tensile strength and 54% increase in the stiffness. With increase in the graphite reinforcement, coefficient of friction and wear rate of PAMC decreases. Coefficient of friction stabilizes between 0.3 to 0.33 and wear rate stabilizes near to 0.00005 mm3/Nm.