Mechanistic performance of Al–Mg–Si alloy reinforced agro-waste residue for structural applications

Al–Mg–Si alloys offer lightweight properties and an excellent strength-to-weight ratio, making them attractive for engineering applications. However, limitations in their mechanical performance have driven interest in reinforcing these alloys with synthetic ceramics and agro-waste residues. Although previous studies have explored plantain peel ash, rice husk ash, and coconut shell ash, comprehensive investigations into cassava peel ash (CPA) and alumina-reinforced Al–Mg–Si alloys remain limited. This study examines the mechanistic performance of CPA/Alumina-reinforced Al–Mg–Si composites manufactured via a two-stage stir casting procedure, with CPA contents of 2–10 wt%. Composites were evaluated for porosity, density, hardness, tensile and yield strength, ductility, E-modulus, toughness, strain at failure, and wear resistance. Microstructural analysis revealed heterogeneous, roundish reinforcement dispersion, with XRF and XRD confirming silica as the dominant oxide phase. The composites exhibited lightweight characteristics with porosity between 0.93 % and 1.94 %. Hardness ranged from 57.10 to 68.24 BHN, tensile strength from 95.35 MPa (CPA-10) to 210.68 MPa (CPA-4), and yield strength peaked at 175.09 MPa (CPA-4). CPA-0 showed the highest toughness (5.55 J) and ductility (12.22 %), while wear resistance improved progressively with CPA, peaking at CPA-10 (1.280 mm/mm³). CPA-4, with 4 wt% CPA and 6 wt% alumina, emerged as the optimal composition, offering an excellent balance of strength, stiffness, and moderate ductility. The findings confirm that cassava peel ash, when optimally hybridized with alumina, can serve as a sustainable, eco-friendly reinforcement, significantly enhancing the mechanical performance of aluminum alloys for broader structural and engineering applications.