Cleaner production of performance-enhanced hybrid composites using agro-industrial wastes: A sustainable waste management strategy

Abstract

Extensive research on developing sustainable hybrid composites using special waste streams as alternative conventional ceramic oxide reinforcements for effective solid waste management is envisioned. This study examines physical and mechanical characteristics of aluminium hybrid composites (AHC) via waste management strategy of reducing, recycling and reusing the bio-mass wastes; Coconut shell ash (CA) and Red mud (RD) at their total concentration of 2, 4 and 6 wt % as reinforcements. The particle size and its elements of the reinforcements are examined by particle size analyzer (PSA) and X-ray fluorescence (XRF) analysis. The composites are produced via the bottom pouring stir casting process. The composites’ morphology, composition, crystallinity via FESEM/EDAX, FT-IR, and XRD studies, mechanical (tensile, compressive strength, micro-hardness and impact energy) and physical (density and porosity) properties are analyzed to assess functionality. Characterization studies confirm the reinforced composites surpass the base aluminium alloy in physical and mechanical properties. Specifically, the composite with 6 wt % (CA + RD) has the potential to improve the base aluminium alloy in terms of density (2.61 g/cc), hardness (100.14 VH), impact energy (2.30 J), tensile (161.09 MPa), and compressive strength (226.05 MPa). Statistical analysis validates the experimental data, confirming the reinforcements as suitable alternatives to ceramic oxides for enhancing metal composites. The LCA results indicate energy consumption (293.12 MJ/kg) and CO₂ emissions (25.11 kg CO₂/kg), emphasizing the need for clean energy adoption and advanced raw material extraction to develop sustainable composites aligned with SDGs 9 and 12 in the construction and energy sectors.