Development of Metal Matrix Composites via Stir Casting Using Recycled Aluminum Alloy Reinforced With Spent Catalytic Converter (SCC) Particles

ABSTRACT

This study introduces an eco-friendly and sustainable approach to developing metal matrix composites (MMCs) by utilizing locally sourced scrap aluminium engine head (SAEH) as the matrix material, reinforced with powdered spent catalytic converter (SCC) particles and Al2O3. The stir casting method was chosen for composite fabrication due to its simplicity and cost efficiency. Microstructural analysis was performed using optical microscopy (OM), scanning electron microscopy (SEM) and energy-dispersive X-ray analysis (EDAX). The mechanical properties of the MMCs, including tensile strength, compressive strength, hardness, and impact resistance, as well as physical properties like density and porosity were investigated. The results demonstrate significant enhancements in the mechanical properties of the composite compared to the as-cast SAEH. The ultimate tensile strength increased from 70.3 MPa (as-cast SAEH) to 158.7 MPa (SAEH+SCC). Similarly, the ultimate compressive strength rose from 513.7 MPa to 717.85 MPa, while hardness improved from 32.56 HB to 45.5 HB. The impact strength also increased from 1.4 Joules to 1.7 Joules. Moreover, porosity was reduced from 14.28% to 8.3%, indicating improved material density and fewer defects. These findings suggest that reinforcing SAEH with SCC particles via stir casting leads to the development of a stronger, more durable composite. The research underscores the potential of using recycled materials to produce sustainable MMCs, aligning with the goals of minimizing environmental impact and enhancing mechanical properties for a variety of engineering applications. Additionally, the study supports the sustainable development goals (SDGs), advocating for environmentally responsible material development that contributes to global sustainability efforts.