A method of self-healing hydrophobic organic coating with gradient texture implantation: Tackling the challenge of bearing corrosion and friction

Abstract

Bearing steel needs protection in marine environments due to its extreme lack of corrosion resistance. However, traditional anti-corrosion coatings face the problem of friction damage. This study proposes a method for self-healing hydrophobic organic coatings implant gradient texture, avoiding the harm of severe wear to the coating. Nano-SiO₂ modified stearic acid coating reduces the friction coefficient of bearings from 0.8 to 0.35 (room temperature) and below 0.1 (high temperature). The stearic acid with state change at high temperatures have a synergistic effect with ester lubricants, which has a lubrication enhancement effect exceeding 20 %. The regeneration behavior of the stearic acid layer is influenced by both metal chemical adsorption and oil interface diffusion. The gradient texture of laser secondary processing changes the equilibrium point of the reaction through anchoring and increasing the area. The additional fluid dynamic pressure generated by the asymmetrical pit texture enhances the lubrication effect. The adsorption rate in finite element simulation is 90 %, and the regeneration rate in the experiment is as high as 98 %, which proves the feasibility of using coatings on the bearing surface. This study provides new ideas for the corrosion and wear protection of bearings under harsh working conditions.