Study On The Space Tribology Property Of Sulfide Solid Lubricating Layer And Coating Materials

In this paper, three different solid lubrication film materials of Ni/MoS2-C, FeS andMo-MoS2were prepared by nano-composite brush plating technology, low temperature ionsulfur technology and magnetron sputtering technology respectively. Space tribologicalperformances of this three sulfur solid lubrication film were studied also. Morphology,mechanical properties, structure and composition of films were analyzed by SEM, XPS, EDS,X-ray stress analyzer, and XRD. Tribological properties of films were studied by MSTS-1friction and wear tester under space which including high vacuum and atom oxygen. TEM wasused to analysis the nano-graphite particles dispersed in the Ni/MoS2-C coating, nano indentationwas used to analysis the mechanical properties of Mo/MoS2film while wear scar morphology ofthree different materials were analyed by SEM.The results shows:(1) Nanoparticle in composite plating reduce the grain size and thestrength of this plating was improved through effects of dispersion strengthening and fine crystalling strengthening. The combination plating gets good tribological properties. Nano graphiteparticles improved moisture resistance property of Ni/MoS2film, Ni-MoS2/C composite film stillretains good tribological properties storage in the atmosphere of100%relative humidity. Atomicoxygen oxidation makes the corrosion effect to the Ni-MoS2/C composite coating obviously.Surface of the Ni-MoS2/C were irradiated after5h storage under AO irradiation. The frictioncoefficient in the early stages gets lower because of oxide film on the surface while damage ofthe overall structure of the lubricating film causes less wear life.(2) FeS sulfide layer with thinness of7μm prepared by low temperature ion sulfur onGCr15matrix, surface of sulfide layer accompanied by a small amount of pore. FeS sulfide layershows low friction coefficient under high vacuum conditions. Oxygen content increasedsignificantly after a few hours irradiation of atomic oxygen and coefficient friction reduced littlecaused by the oxidate; the surface oxide formed after a certain time irradiation of atomic oxygenmake curve of friction coefficient appeared local fluctuations. (3) Mo/MoS2composite solid lubricating film material with thickness of about2μmprepared by using magnetron sputtering elemental molybdenum film assisted low temperatureion seepage GCr15matrix. Space tribology test results shows that under vacuum magnetronsputtering elemental molybdenum film does not have the lubrication of antifriction whileMo/MoS2by low temperature ion seepage in a high vacuum environment showed friendshiptribological.The sputtering effect of the space of atomic oxygen damage the flatness of thesurface of the composite film, the initial friction coefficient of the film after irradiation by atomicoxygen is higher than the unirradiated composite film, when frictional wear stable film stillshowed excellent space tribology performance.