Sustainable aluminum matrix composites (Al MMCs) reinforced with rice husk fly ash (RHA): Mechanical and wear performance

Abstract

Al MMCs reinforced with rice husk fly ash (RHA) were fabricated by stir casting at 760 °C using pure commercial Al 1050 (CP-Al) alloy with 5 wt.% and 10 wt.% reinforcement. The addition of RHA refined the microstructure, reducing the average grain size from ∼55 µm to 33 µm, while suppressing columnar dendritic growth through particle-assisted nucleation. Mechanical properties improved, with the 10 wt.% RHA composites showing a 77% increase in hardness and a 61.25% increase in UTS, resulting from combined grain refinement & thermal mismatch effects. XRD and SEM results confirmed the interfacial stability of Al and RHA. The composites also exhibited superior wear resistance under loads of 20–60 N due to the load-bearing and wear-inhibiting role of RHA particles.