This study investigated the three-body abrasive wear behavior of heat-treated and as-cast Al LM6 and its composites reinforced with hematite (Fe 2 O 3 ) particles (0–12 wt.%) under varying loads (2–10 N) and speeds (40–200 rpm). The composites were produced through stir casting, a scalable and resource-efficient manufacturing technique suitable for automotive engineering applications. Microstructural examination revealed a dichotomy in the reinforcement effects: lower levels (3–6 wt.% Fe 2 O 3 ) promoted uniform particle dispersion, strong interfacial bonding, and minimal porosity, while higher levels (≥9 wt.%) led to particle agglomeration, micro void development, and decreased matrix cohesion. According to the quantitative wear data, the weight loss increased with the applied stress but decreased with increasing Fe 2 O 3 content. The as-purchased LM6 exhibited the highest wear (∼2.5 mg) at 10 N, whereas the LM6+12%Fe 2 O 3 heat-treated composite showed the lowest wear (∼0.5 mg). The findings demonstrated that while increasing the sliding speed decreased the weight loss by approximately 15–30%, increasing the applied stress enhanced the weight loss by approximately 20–35%. In comparison to similar as-cast composites, increasing the Fe 2 O 3 content decreased the weight loss by approximately 25–35%, while heat treatment resulted in an additional 10–20% reduction. Overall, the three-body abrasive wear resistance of the LM6 composites was significantly improved by the combination of heat treatment and Fe 2 O 3 reinforcement. The wear loss decreased with increasing rotational speed, and the best performance was shown by the LM6+12% Fe 2 O 3 heat-treated composite at 200 rpm. In all scenarios, heat treatment reduced the weight loss by 30–45%. The contributions of the matrix hardness, improved particle–matrix bonding, and protective tribo-layer development were highlighted by the SEM images of the worn surfaces. These findings collectively demonstrate that optimal reinforcement levels (6–9 wt.% Fe 2 O 3 ) combined with heat treatment significantly enhance the wear resistance of Al LM6 composites, supporting the development of durable, lightweight, and sustainable aluminum composites for automotive components, thereby contributing to extended service life and reduced material consumption. The main innovation of this study is the use of naturally occurring hematite (Fe₂O₃) as an affordable and sustainable substitute for traditional Al₂O₃/ZrB₂ reinforcements. It also establishes the coupled effects of load, sliding speed, and heat treatment, and clarifies the three-body abrasive wear mechanism.
