Microstructures And Tribological Properties Of Solid Lubrication Films Prepared By Sputtering And Ion Sulfuration

Wear is one of the major failure modes of machine parts. In order to improve the performances of parts and service life, traditional methods are to use lubrication oils. But lubrication oils could lose their lubricity under some harsh conditions, such as high temperature, high pressure, high speed and vacuum. Therefore solid lubrication is an effective approach which is suitable for the components operating in the above mentioned conditions, and can decrease evidently their wear.In this dissertation, the two-step methods, namely magnetic sputtering + low temperature ion sulfuration were used to prepare six kinds of solid lubrication films containing WS2, MoS2, and FeS on the AISI 1045 steel or M2 high-speed steel. As comparison, the microstructure of solid FeS was researched. The tribological properties of the films were investigated on T-11 ball-on-disk friction and wear tester, MMS-1G high speed and high temperature wear tester, under dry and oil lubrication conditions respectively. Scanning electron telescope(SEM) were used to observe the morphologies of films and solid FeS, X-ray Diffraction(XRD) were employed to analyze the phase structures, X-ray stress determinator were used to measure the residual stress of films, the nano-hardness and elastic modulus were surveyed by the nano-indentation tester.The experimental results show that the bonding strength between the six kinds of solid lubrication films and the substrates are very well, the mechanical performance of the films are excellent. The tribological properties of the films are all superior to the non-treated steels. Furthermore, the friction-reduction and wear-resistance performance of the multilayer films were better than that of single film.WS2,MoS2 and FeS all possess the close-packed hexagonal lattice structure, with low shearing force, slippage happens easily along the closed-packed plane, so the frictional coefficient is very low. In the frictional process, the solid lubrication films can be spread on the surface of counterpart, fill in the valleys of rough surfaces and effectively prevent the direct contact between metals and avoid the occurrence of adhesion.The theoretical research and partial practicable application of this dissertation demonstrated that, due to their excellent performance of friction-reduction and wear-resistance, the sulfide solid lubrication films can give play to the obvious functions, for example, energy-saving, resource-conserving, environment-protecting and discharge-reducing, and then have a brilliant prospect.