Tribological Properties of Laser Microtextured Surface Bonded With Composite Solid Lubricant at High Temperature

Abstract

A combination technology of the solid lubricant and the laser surface texturing (LST) can significantly improve the tribological properties of friction pairs. The plate sample was textured by fiber laser and composite lubricant of polyimide (PI) and molybdenum disulfide (MoS2) powders were filled in the microdimples. Sliding friction performances of micronsized composite lubricant and nanosized composite lubricant were investigated by ringplate tribometer at temperatures ranging from room temperature (RT) to 400 آ°C. On the one hand, the results of the micronsized composite lubricant show that the friction coefficient of the textured surface filled with composite lubricant (TS) exhibits the lowest level and the highest stability compared to a textured surface without solid lubrication, smooth surface without lubrication, smooth surface burnished with a layer of composite solid lubricant. The better dimple density range is 35–46%. The friction coefficients of the sample surface filled with microncomposite solid lubricant with the texture density of 35% are maintained at a low level (about 0.1) at temperatures ranging from RT to 300 آ°C. On the other hand, the results of the nanosized composite lubricant show that these friction properties are better than those of MoS2PI micronsized composite. The friction coefficients of MoS2PICNTs nanosized composite solid lubricant are lower than those of the MoS2PI composite lubricant at temperatures ranging from RT to 400 آ°C. In addition, the possible mechanisms involving the synergetic effect of the surface texture and the solid lubricant are discussed in the present work.