In-situ reinforcement of AA6063/Al2O3 hybrid composite: comparative wear and hardness evaluation of Manihot esculenta and green Plantago major particulates

Abstract

AbstractThe AA6063 alloy, renowned for its resistance against corrosion and favourable mechanical properties, has limited applications within the automotive and aerospace sectors owing to its reduced hardness and wear properties. Manihot esculenta and Plantago major are essential food crops contributing to environmental pollution. This study repurposes the Manihot esculenta peel ash (MEPA) and Plantago major peel ash (PMPA) as innovative reinforcements for the in-situ fabrication of Al2O3/AA6063 hybrid and monolithic composites (HMCs) using the two-step stir casting method. MEPA/Al2O3/AA6063 and PMPA/Al2O3/AA6063 HMCs, fabricated with novel weight percentage variations of 2, 4, 5, 6, 8, and 10%, underwent mechanical and tribological investigations. Although previous studies have examined the physio-mechanical properties of MEPA and PMPA in hybrid composites, their tribological performance remains unexplored. Additionally, using MEPA and PMPA as reinforcing elements in a monolithic aluminium matrix is novel. Oxide compositions and chemical constituents in MEPA and PMPA powders were determined, with fabricated MHCs characterized for SEM and energy-dispersive X-ray studies. Results revealed the presence of hard particulates, including SiO2 (44%), Al2O3 (16%), K2O (13%), CaO (12%), and Fe2O3 (8%) in MEPA powders, while PMPA powders were dominated by K2O (81%). Morphological studies showed uniform dispersion of reinforcements within the matrix. Composite hardness and wear resistance improved with rising MEPA weight ratios, contrasting with decreasing trends in PMPA particulates. Comparatively, MEPA showed a superior impact on the hardness and tribological performance of Al2O3/AA6063 HMCs compared to PMPA These findings highlight MEPA and PMPA as sustainable engineering solutions for aluminium matrix reinforcement.