Investigation of tribological and corrosion properties of B4C, H-BN and B5H10NAO13 added composite coatings grown on aluminum alloy

The Al 7075 alloy is a strategic engineering material widely used in the aerospace, defense, and automotive industries due to its low density, high specific strength, excellent machinability, ductility, high toughness, and fatigue resistance. However, despite these outstanding mechanical properties, its relatively low fracture toughness, limited damage tolerance, and susceptibility to corrosion under environmental conditions restrict its use in certain advanced structural applications. These shortcomings, particularly critical for long-term service conditions of aircraft components, emphasize the necessity of surface enhancement techniques. Ceramic-based coating methods applied to aluminum and its alloys offer an effective solution for improving surface characteristics by providing high hardness, superior wear resistance, and enhanced corrosion protection. In this context, ceramic coatings produced by the Micro Arc Oxidation (MAO) process have emerged as a widely preferred and efficient surface modification technique in surface engineering applications. In the present study, composite coatings were fabricated on 7075 aluminum alloy via the MAO method using three different boron-based additives (B₅H₁₀NaO₁₃, B₄C, and h-BN) to improve the surface properties of the alloy. The study was conducted in three stages: in the first stage, reference Al₂O₃ coatings were produced; in the second stage, composite coatings were synthesized by individually incorporating the three boron-based additives; and in the third stage, the microstructural, mechanical, tribological, and corrosion properties of the resulting coatings were comprehensively characterized. The findings demonstrate that the boron-doped composite coatings significantly improved the surface properties of the Al 7075 alloy, providing notable enhancements in both wear and corrosion resistance. These results indicate that boron-containing composite coatings have strong potential for contributing to both academic research and industrial applications in the field of surface engineering for lightweight metal alloys.