Exploration of aviation bearings protection: Highly corrosion-resistant and wear-resistant biomimetic composite coatings inspired by mussels

Abstract

Aircraft engines are subject to salt spray erosion in marine environments, and the protection of bearings faces a dual challenge of anti-wear and anti-corrosion. This paper was inspired by mussels and prepared a polydopamine nano-SiO₂ modified stearic acid composite organic coating on the surface of bearing steel by in-situ polymerization. The results indicate that the composite coating has excellent corrosion resistance in seawater, reducing the current density from 3.87 × 10⁻⁵ A/cm² to 2.13 × 10⁻⁷ A/cm². The biomimetic microstructure effectively enhances the hydrophobicity of the coating, increasing the contact angle from 76.84° to 145.1°. The composite coating exhibits plastic deformation under high stress conditions of 17.55 GPa, with a stable friction coefficient between 0.11 and 0.12. According to first principles calculations, polydopamine as an intermediate layer increases the minimum interfacial energy from 14.11 kJ/mol to 23.96 kJ/mol. This polymer dopamine nano-SiO₂ modified stearic acid composite organic coating is expected to be used in moving parts such as aircraft bearings to reduce corrosion and wear, and extend service life.