Tribological Performances and Friction Reduction Mechanism of N-Al2O3/FeS Solid Lubrication Duplex Layer

Abstract

FeS solid lubrication duplex layer was prepared on the surface of 45 steel by ion nitrocarburizing-ion sulphurizing process. The sulphide grains in micron and nano scale and holes distributing equably on the duplex layer. The n-Al2O3 particles in liquid paraffin oil were set into the holes in micron and nano scale of the duplex layer by using vacuum dipping process to prepare the n-Al2O3/FeS solid lubrication duplex layer. Friction and wear performances of the n-Al2O3/FeS solid lubrication duplex layer were investigated to be excellent under different loads and temperatures. The causes are as follows: the solid lubrication function of FeS solid lubrication duplex layer, the “micron nano bearing” function of the nanoparticles embedded in the micron nano pores of FeS solid lubrication duplex layer, and oil lubrication are integrated by nanoparticles/FeS solid lubrication duplex layer and exert synergic lubrication function under high temperature and over loading condition. so the coefficients of friction and volume loss of the n-Al2O3/FeS solid lubrication duplex layer under load 60N and temperature 150°C are 10% and 31.3% lower than those of the FeS solid lubrication duplex layer lubricated by the n-Al2O3 additive, respectively.