| Magnetic fluids (MF) are stable colloidal systems consisting of single-domain magnetic particles,dispersant and carrier liquids, which possesses super paramagnetic. Under an external magnetic field,it can be confined, positioned and controlled. For the special properties, MF has been widely used insealing and lubrication of bearings.Here, the magnetic surface is a kind of surface covered with micro magnetic film arrays. As themagnetic arrays can generate periodic gradient magnetic field on the substrate surface, MF which caninteract with magnetic field was chosen as lubricant for such surface.The magnetic functional surface was manufactured by using the photolithography,micro-electrochemical machining and electrodepositing methods. Then the magnetic field distributionof such surface was analyzed by using the finite element analysis software. The kinetic/static frictionforces and adhesive force of the magnetic surface as well as non-magnetic surface lubricated with MFwere tested. The main research results are as follows:Compared with the non-magnetic surface, the magnetic surface showed obvious lubricationadvantages in high speed condition. The thicker magnetic film thickness and higher area ratio, thebetter anti-friction effect it appeared. However, the friction increased for the magnetic surface at thelow speed. While in the high-speed and heavy load condition, the magnetic surface can effectivelyreduce wear, the surface with thicker film and higher ratio show better wear resistant.The static friction coefficient of the magnetic surface was lower than that of the non-magneticsurface at the light load condition, and the coefficients also reduced with the increase of the magneticfilm thickness and area ratio. But in the heavy load, there is no obvious changes for the magnetic andnon-magnetic surface.Magnetic functional surface can significantly improve the adhesive force. As the increase ofmagnetic film thickness and area ratio, the adhesive forces increased gradually. |
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