Integration and performance response of biowastes snail shell ash–reinforced AA6063 alloys: Interfacial effect, mechanical and corrosion properties

Traditional AA6063 aluminium alloy, while suitable for architectural applications, exhibits limitations in mechanical durability and long-term corrosion resistance in aggressive environments. Furthermore, conventional ceramic reinforcements are costly and energy-intensive. Aim: This study aims to develop eco-friendly, high-performance aluminium matrix composites (AMCs) by reinforcing AA6063 with snail shell ash (SSA), an agricultural waste, for potential use in ceiling systems. Composites with 0-25 wt.% SSA were fabricated via stir-casting. Microstructure was characterized using SEM/EDS and XRD. Mechanical performance was evaluated via hardness and pin-on-disc wear tests. Corrosion behaviour was assessed in 1 M HCl (30-60°C) through open-circuit potential (OCP), potentiodynamic polarization, and electrochemical impedance spectroscopy. Statistical optimization was performed using Response Surface Methodology (RSM). Microstructural analysis revealed grain refinement and homogeneous SSA dispersion. Hardness increased by 21.6% (to 35.5 HRB) and wear rate decreased by ∼12% at 25 wt.% SSA. Electrochemical tests showed a positive OCP shift up to +0.342 V, a 65% reduction in corrosion current density, and a 15% increase in polarization resistance. RSM identified an optimal formulation of 24.97 wt.% SSA at 30.01°C, yielding a minimal corrosion rate of 0.43 mm/yr. Adsorption isotherms confirmed physisorption as the primary inhibition mechanism. Conclusion: SSA is an effective, low-cost reinforcement that synergistically enhances the mechanical and corrosion properties of AA6063 composites via microstructural refinement, barrier effects, and the formation of protective phases. This work provides a sustainable pathway for valorizing biowaste in engineering materials..