Abstract: Ceramic reinforced aluminum matrix composite materials are gaining wide acceptance in the engineering application because of their low density, high strength and good structural rigidity. Inclusion of MgO particulates as reinforcement in aluminum LM13 alloy material composite improves its hardness. In the present investigation aluminum LM13/MgO composites were developed by vortex method by varying the weight percentage of MgO particulates from 0wt% to 10wt% in the steps of 2wt%. The casted matrix alloy and its composites have been subjected to solutionizing treatment at a temperature of 530° C for 2 hours, followed by quenching in different media such as air, water and ice. The quenched hardness specimens were subjected to artificial aging at 164° C. Microstructural studies were carried out to understand nature of structure. The hardness test was conducted on both aluminum LM13 alloy and aluminum LM13/MgO particulate composite, before and after heat treatment. Aluminum LM13/MgO particulate composites exhibited significant improvement in hardness when compared with aluminum LM13 alloy.