Effect of Various Ceramic Particles on the Microstructure, Hardness, Density, and Wear Behavior of Al/Al2O3 Hybrid Composites Produced by Ball Milling

Abstract

The automotive, aerospace, and defense industries require the development of advanced lightweight composites with exceptional mechanical and tribological properties. This work examines the effects of adding various ceramic particles to mechanically alloyed aluminum/alumina (Al/Al₂O₃). Reinforcement agents were selected due to their unique contributions to wear resistance, density, hardness, and microstructural refinement. These include silicon carbide (SiC), carbon nanotubes (CNT), nanosilica (NS), nanoclay (NC), and rare earth oxides (La₂O₃, Nd₂O₃, and Sm₂O₃). The comprehensive characterization methods used to evaluate the structural and functional performance of the composites included Vickers microhardness testing, FTIR spectroscopy, FESEM imaging, EDS mapping, density measurements, and tribological wear testing. FTIR analysis confirmed that the ceramic additives bonded solidly to the matrix. Furthermore, the friction resistance was found to be enhanced by NS and CNT. Although some adhesive wear was observed in CNT-reinforced samples, SEM images of the wear tracks showed that abrasive wear consistently remained the predominant mechanism across all composites. Overall, the findings demonstrate that, by carefully selecting and combining ceramic reinforcements, Al/Al₂O₃ can be effectively modified to increase hardness, density, and resistance to wear. Because of this, these materials are desirable choices for engineering applications requiring lightweight construction, high stress, and high wear.