Friction Performance and Condition Adaptability of Sinusoidal Gradient-Textured Solid Lubrication Composite Coatings

Combining surface texturing and solid lubricant coating is an effective approach to improve tribological performance and service life in surface engineering. However, few studies have systematically compared texture types and their adaptability to varying working conditions. In this work, a textured composite coating with a three-level gradient structure (interface texture–coating–surface texture) was prepared via plasma spraying and laser texturing. Reciprocating dry friction tests were carried out to compare the tribological properties of dimple, linear, and sinusoidal textures. The effects of normal load and sliding speed on friction and wear behavior were investigated. Results demonstrate that the average friction coefficients follow the order: non-textured coating > dimple-textured coating > linear-textured coating > sinusoidal-textured coating. The sinusoidal texture provides the lowest friction coefficient and superior debris capture and storage capacity, which effectively mitigate abrasive wear, adhesive wear, and fatigue spalling, leading to optimal friction reduction. Increasing the load moderately reduces the friction coefficient, but the coating fails rapidly due to severe plastic flow and adhesive tearing when the load exceeds 100 N. The textured composite coating presents favorable velocity adaptability with a friction coefficient reduced by 23.8%–41.3% relative to the non-textured coating. Yet the texture fails rapidly when the sliding speed exceeds 100 mm/s because of intensified adhesive wear and plastic deformation.