Tribological Performances of FeS Solid Lubrication Duplex Layer under Liquid Paraffin Oil with n-Al2O3 Lubrication

FeS solid lubrication duplex layer was prepared on the surface of 45 steel by ion nitrocarburizing-ion sulphurizing process. The sulphide grains and holes all in micron and nano scale and distributing equably in the sulphide surface layer with 10 mu m thickness of the duplex layer. The duplex layer is composed of FeS, FeS2 and Fe3N. Under liquid paraffin oil with 0.1wt% n-Al2O3 lubrication, the synergistic effect between n-Al2O3 and the duplex layer is produced, and the chemical reaction films including sulphide, sulphate and nitride is formed, which makes the friction factor of the duplex layer keep being the lowest and about 0.07, and the volume loss is reduced by 97% than that of the plain surface(rubbing for 10 min), and reduced by 92% and 21% than that of the sulphurized surface and the nitrocarburized surface, respectively.