Investigating run-in and steady-state wear mechanisms of Al-7075 alloy hybrid composite for brake rotor applications

An effective way for creating superior-grade metal matrix composites (MMCs) using Al composites is the stir-casting technique. Stir-casting stands out among the array of available methods, being a frequently adopted technique. This study focuses on producing Al7075/B4C + Al2O3 hybrid MMCs by incorporating different weight proportions of Al2O3 (3–12%) while maintaining a consistent weight proportion of B4C (6%). The microstructural analysis demonstrates that the B4C/Al2O3 particles are evenly dispersed throughout the Al matrix. A complete investigation was carried out to evaluate the Run in and steady state wear mechanism and hardness throughout distinct phases. Notably, when contrasted with the interface and matrix phases, the particle phase (Top phase) of the hybrid composites achieves the highest hardness. The wear rate and coefficient of friction of the composites were both decreased by the addition of B4C/Al2O3 particles. The composites reinforced with B4C/Al2O3 showed the greatest decreases in wear rate and coefficient of friction. A comparison of the wear characteristics of the created composite and the conventional brake drum material, namely cast iron, was also done with regard to industrial sustainability. It was discovered that the wear rate of B4C/Al2O3-reinforced composites was comparable to that of automotive industry-used cast iron brake drums. According to SEM data, abrasive wear at lower stresses and adhesive wear at higher loads mostly helped in material removal.