MMC based on aluminium (Al) were produced for light-weight applications especially in aviation and automobile areas. Present paper deals with the fabrication and mechanical performance of AA6061 matrix composites fortified with Al₂O₃ (alumina) and graphene particulates. Fluid metallurgy method namely stir casting route was employed for fabricating the hybrid composites. Al₂O_3p and graphene powder are mixed in different weight fractions in which graphene (1 wt. %) particle reinforcement is held consistent and Al₂O₃ reinforcement is differed freely with 5, 10 and 15 wt. %. Using optical analyser and SEM equipment, microstructural examination is carried out and the result reveals that the graphene and Al₂O₃ particles prevalently are homogeneously appropriated on the grain limits of Al matrix and Al₂O₃ particles are disseminated between graphene in the as-cast AA6061 MMC’s. Detailed analysis on investigation of the microstructure and mechanical aspects of Al6061-graphene-Al₂O_3p composites is presented by following ASTM guidelines; results uncovered that with increment in reinforcement particles, there is an enhancement in the hardness, ultimate strength, yield strength and a decline in the elongation values was however noticed when contrasted with Al6061 alloy. Fractography investigation revealed dimples in unreinforced alloy and the composite.

Al2618 alloy composites containing 6 wt% nano B₄C were prepared by liquid metallurgy two stage stir casting process. Characterization was performed using scanning electron microscope to validate the homogenous distribution of nano B₄C particles in the Al2618 alloy matrix. The presence of B and C elements was confirmed by EDS analysis in the nano B₄C reinforced metal composites. The mechanical behavior of the prepared nano composites were evaluated as per the ASTM standards, and it was noted that the tensile strength (ultimate strength and yield strength) and compression strength increased with the addition of 6 wt% nano B₄C particles. Finally, to understand the failure mechanisms the fractography analysis was conducted on the broken tensile specimens by using SEM images.

In the present investigation synthesis, microstructure, mechanical and wear behavior of 5 weight percentage of nano Al2O3 particulate reinforced AA7475 alloy composites has been reported. AA7475 matrix composite containing nano Al2O3 were fabricated by conventional stir casting method. The microstructures of the composites were examined by scanning electron microscopy. Further, mechanical and wear behavior of as cast AA7475 alloy and AA7475 - 5 wt. % nano Al2O3 composites were studied. Mechanical properties like hardness, ultimate, yield strength and percentage elongation were evaluated as per ASTM standards. Pin on disc apparatus was used to conduct the dry sliding wear tests. The experiments were conducted by varying loads and constant sliding speed of 300rpm for sliding distance of 4000m. Microstructural observation revealed the uniform distribution of particles in the AA7475 alloy matrix. From the analysis, it was found that the hardness, ultimate tensile strength and yield strength of composites were increased due to addition of nano Al2O3 particle in the AA7475 alloy matrix. Percentage elongation of the composite decreased in 5 wt. % nano Al2O3 reinforced composites. Further, the volumetric wear loss was found to increase with the load and sliding distance for all materials. Worn surface analysis made by using scanning electron micrographs to know the various mechanisms involved in the wear process.