Influence of SiO2 and nano graphene particles on the microstructure and mechanical behavior of A356 alloy metal composites

The current research focuses on investigating the microstructural and mechanical properties of aluminum (Al) metal matrix composites (MMCs) reinforced with both silicon dioxide (SiO2) and nano-graphene particles. The composite material was produced using a novel two stage stir cast metallurgy approach. In this study, a constant reinforcement of 1 wt. % nanographene was maintained, while the SiO2 content was independently varied at levels of 2.5, 5, and 7.5 wt. %. Employing scanning electron microscopy (SEM) tool, microstructural analyses were conducted, revealing a uniform dispersion of ceramic silicon dioxide (SiO2) and graphene particles within the as-cast A356 MMCs. Mechanical testing, following the ASTM standards, was carried out on the composites, specifically assessing tensile strength, yield strength, and percentage elongation to evaluate the properties of the Al-based MMCs. The findings of this study indicate a significant enhancement in both tensile and yield strength values for the fabricated composites by 60.64% and 82.78% respectively. However, it is important to note that the percentage elongation decreases as the reinforcement content in the composite increases.