Influence of Nano Reinforced Particles on the Mechanical Properties of Aluminium Hybrid Metal Matrix Composite Fabricated by Ultrasonic Assisted Stir Casting

During the past few decades, materials design has shifted emphasis to pursue low cost, quality, light weight, environment friendliness, and performance. Aluminium matrix composites are important class of engineering materials used in aerospace, automotive, engineering, defence and other industries because of their lower density, higher specific strength, and better physical and mechanical properties. Aluminium Matrix composites are projected to significantly reduce the overall weight of the vehicles while maintaining satisfactory structural strength. Reinforcement of micro or nano-sized range particles with aluminium matrix yields improved physical and mechanical properties in composite materials. In this paper, we have investigated the effect of ultrasonic stirring in aluminium matrix composite with micro silicon carbide particles (fixed 5% wt.) and Nano Graphene (1, 3 and 5% wt.). Al356 was used as a matrix material. Micro SiC and Nano graphene produced by reduction of Graphite oxide Method were added as the hybrid reinforcements in varying proportions. Al 356 alloy/ (Graphene + SiC) hybrid composites with different hybrid ratios were synthesized using semisolid stirring assisted ultrasonic cavitation method. For comparison, an Al356 alloy + 5% SiC sample was also casted under the same conditions. Various properties of composites like tensile strength, ductility, Flexural strength, hardness, impact strength were measured and compared with Al356 + 5% SiC sample. The application of ultrasonic vibration on the composite during melting refined the grain structure of the matrix, and improved the distribution of nano-sized reinforcement. From the results of tensile test, it is found that the value of tensile strength increases with increase in Wt. % of graphene. The hardness of composites with 3% Nano graphene is higher than 1 and 5 % Nano graphene. The presence of Nano graphene in Al 356 alloy SiC composites validates the fact that, there is an improvement in mechanical properties.