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Modified WS2 by silane coupling agent were encapsulated in the dimples fabricated on the surface of cylinder liner samples by hot-pressing method. The tribological properties, anti-adhesion performance of the samples as well as the releasing behavior of modified WS2 in the dimples were tested by a reciprocating tribotester. Moreover, the anti-erosion performance of modified WS2 was examined by ultrasonic vibration test. The results indicate that the composite lubrication structure has good anti-friction and anti-adhesion effects. Furthermore, the release rate of WS2 in the dimples is decreased by 102.2% due to the introduction of silane coupling agent. Additionally, the synergistic effect among the dimples, the solid lubricant and the silane coupling agent can explain the anti-friction and sustained release mechanisms.

A surface texture produced by three-step microarc oxidation (MAO) was optimized to improve the tribology performance of a self-lubricating composite coating for diesel engine piston skirts. WS2 was introduced into the self-lubricating composite coating as a self-lubricating additive. The effects of MAO’s varying electrical parameters in terms of stages and action time on the microstructure and chemical composition of the coatings were analyzed by XPS mapping, micron CT, SEM, XRD, and EDS mapping. Furthermore, friction-wear tests under dry lubricating were employed to evaluate the self-lubricating property of the composite coating. Compared to the bare ZL109 aluminum alloy, the optimized composite coating’s friction coefficients were reduced by 60%. Notably, the wear loss of cylinder liner samples matched with the optimized composite coating was almost zero under this work condition.

Ceramic based self-lubricating coating was successfully fabricated on Al-based plasma electrolytic oxidation (PEO) ceramic coating in this work. The coating was reinforced with thermosetting polyimide (PI) containing tungsten disulfide (WS2) fillers. The morphology, chemical composition and phase structure of the PEO, PEO/PI and PEO/PI/WS2 coatings were observed by SEM, EDS and XRD, respectively. Tribological properties of the coatings were comparatively investigated using a reciprocating pin-on-block tribotester under different conditions. Under dry sliding conditions, the friction coefficient of PEO/PI/WS2 coating was about 0.4, which was 50% lower than that of PEO coating. Meanwhile, the wear rate of counter pin cooperated with PEO/PI/WS2 coating was only 0.04 mg min−1, which was 90.9% lower than that of PEO coating. Under step loading conditions, the load was ultimately increased to 70 N and the total duration time was about 35 min, while the corresponding values of PEO coating were 30 N and 13 min, respectively. These are owed to the hard ceramic coating and the soft self-lubricating coating, which can improve the load capacity and decrease the friction, of the ceramic based self-lubricating coating.