In this paper, the effects of reinforcements on the mechanical behavior of the cast aluminium-based composites are investigated. The reinforcing materials B4C, SiC, and Graphite with different weight percentages (3%, 6%, 9%, and 12%) are used to fabricate the composites. The composite with 12% by weight exhibits the highest hardness and tensile strength. This paper identified the changes in the behavior of mechanical properties such as tensile strength, hardness, and elongations of the Hybrid Composite & SEM test is used to determine the microstructures of the composite material.