Effect of TiB₂ content on mechanical and tribological properties of stir-cast Al6082–TiB₂–Gr–Mg hybrid composites

Abstract Aluminium alloys are widely used in aerospace and transportation, but their limited wear resistance remains a major drawback. To address this, Al6082-based hybrid composites reinforced with titanium diboride (TiB 2 , 3–9 wt%), graphite (Gr, 1 wt%), and magnesium (Mg, 1 wt%) were fabricated by stir casting. Their microstructure, hardness, tensile strength, wear rate, and coefficient of friction (CoF) were investigated. Taguchi design with ANOVA identified significant factors, while regression analysis and machine learning models (linear regression and random forest) were applied for predictive evaluation. The addition of TiB 2 enhanced hardness and tensile strength but reduced ductility. The 9 wt% TiB 2 composite exhibited the lowest wear rate (0.0045 mm 3 m −1 ), while 3 wt% TiB 2 showed the lowest CoF (0.18) due to stable tribo-layer formation. These findings imply that such composites can replace conventional alloys in high-load automotive and aerospace parts.