Physico-mechanical properties, tribological behaviour and metallurgical characteristics of aluminium metal matrix composites reinforced with agricultural residues: A Review

Abstract

Aluminium Metal Matrix Composites (AMMCs) that are reinforced with agricultural residues (such as rice husk ash, coconut shell ash, sugarcane bagasse ash, maize/corn-cob ash, palm kernel and shell ash) have garnered increasing attention as environmentally friendly, low-cost, and lightweight alternatives to traditional ceramic reinforcements. This review gathers recent findings on (1) physico-mechanical properties (tensile strength, hardness, ductility, density), (2) tribological behaviour (wear rate, friction coefficient, wear mechanisms), and (3) metallurgical characteristics (microstructure, interfacial bonding, phase formation, porosity) of agro-reinforced AMMCs. The review describes common synthesis methods (stir casting and powder metallurgy), emphasises critical microstructure–property correlations, pinpoints persistent challenges (particle agglomeration, inadequate wettability, porosity, variable pre-treatment) and optimisation process. Key fabrication techniques are briefly outlined, and future research directions encompassing hybridisation techniques and surface modifications are provided.