Tribological Study of AA7075—Graphene—Kaolin Hybrid Composite Fabricated Through Powder Metallurgy Route

This study explores the fabrication of aluminum alloy (AA7075) metal matrix composites (AMMCs) using the powder metallurgy technique. The composites incorporate graphene and kaolin as reinforcing particles, with varying weight percentages (wt. %). The kaolin clay varies from 3 to 12% by weight, while graphene particles are kept constant at 0.5% by weight for all AMMCs. AA7075 alloy is chosen for its significant use in constructing lightweight structures that require high strength-to-weight ratios and enhanced wear resistance. The focus of the research is on developing Al-based MMCs with superior wear resistance. To assess tribological properties, pin-on-disc testing is performed under dry sliding conditions, evaluating wear resistance in different scenarios. The tribological analysis considers various MMCs under a 20 N applied load and 1 m/s sliding velocity. Results indicate that the hybrid MMC, AA7075—0.5% Graphene—12% Kaolin, outperforms other fabricated MMCs. This specific combination exhibits the lowest coefficients of friction (COF), wear rate values, and maximum hardness value, measuring 0.73, 0.3712 × 10–6 mm3/m, and 60.1 HRB respectively.