Influence of preload on the tribological performance of MoS2/GO composite lubricating coating

Lubrkaticn is one of d. key iact iota rs to epsilon iota iota wue the teliable operation of sliding parts for some ctitical components in aerospace. The most fa. orabte lublication perfoimance of upsilon.e Itd:trkati:4 film is always achieved after the initial period or the pi emuming -in period. in this work the influence of preloads varying from. 0.5 to 15 N on the nibological perfonnance of molybdenum disttlfide/graphene odde (MoS2/GO) composite lubricating coating was studied. It was fottnd that the coefficient of friction (COF) during the numing-in period decreased from 0.17 at 0.5 N to 0.14 at 5 N, and stabilized at 0.14 with fiuther increasing the nomialload, indicated that the optimal stable COF was obtained at 5 N and negligible changes when load is furthet increased from 5 to 15 N. In contrary to the widely reported coatings that their ulbological tesults deterimate at high applied loads, the MoS2/GO cornposite lubricating coating here exhibits meh lower COF undet higher loads, with the COF decreased from 0.14 at 5 N to 0.03 at 100 N. 1he results suggests that the preload had a positive effect on the tribological perfomiance of the MoS2/GO cornposite coating, the COF of the composite coating decreased with the increase of the preload, which huther improved the tribological properties and even achieved the optimized lubrication condition, and the optinnun preload was egttal to or slightly higher than the steady-state load. This work provides a guiding idea for the selection strategy of the preload for optirnal tfibological pmformance of the solid lublicating coating.