Tribological performance of MoS2 coating on slipper pair in axial piston pump

This study investigates tribological performance of MoS 2 coating on slipper pair in axial piston pump. Firstly, the MoS 2 coating on the surface of slipper pair was prepared by atmospheric plasma spraying treatment technology. Secondly, the tribological characteristics of slipper pair under various working conditions were evaluated on ring-on-block tester in oil lubrication. The original and worn surfaces of the specimens were analyzed with scanning electron microscope and energy dispersive spectrometer, and then the wear morphologies of the MoS 2 coatings were imaged by X-ray photoelectron spectroscopy. The experimental results showed that the friction coefficients of Cu-based materials with MoS 2 coating decreased by about 0.05 at 800 N. Especially, when the external load was set to 800 N, the wear rate of the ZY331608 decreased by about 16.4% after the substrates were treated by the MoS 2 coating, which exhibited excellent anti-friction and wear resistance. The formation of the MoS 2 lubricating film could be classified into four stages, including the initial friction stage, anchoring stage of MoS 2 on friction surface, covering stage of the sliding surface by MoS 2 and the formation stage of MoS 2 film. The dominating wear mechanisms of Cu-based materials with MoS 2 coating were adhesive wear and abrasive wear accompanied with oxidative wear.