Study On The Preparation Of Attapulgite/CeO₂ Friction Restoration Material And Tribological Properties

The research used the attapulgite from Guanshan,anhui province as raw material. The results of X-ray diffraction（XRD）,scanning electron microscope （SEM）,and complete chemical analysis show that the main mineral composition of raw material is attapulgite and with a small quantity of quartz.Using infrared spectrum analysis and laser Raman spectroscopy analysis to investigate its structure characteristics and BET method to determine its specific surface area and pore structure.To improve the attapulgite powder’s dispersion and suspension stability in the lubrication oil, the span60 was chose to modify the attapulgite’s surface.The optimized surface modification conditions had been confirmed by single factor experiments and orthogonal experiments which would be as follows:the amount of modification agent is 55%, the proper modification temperature is 78℃and the modification time is 40 minutes.The order of the modification effect on the size of the influence degree sequence is:modification temperature,modification time,amount of modification agent. It was analysed that,the modification mechanism of span60 is space resistance stability mechanism,namely span60 molecules combine with powder particles mainly in the state of physical adsorption,and the chemical-reaction bonds could be exsit simultaneously.Attapulgite/CeO₂ composite powders were synthesized by the auto spread combustion of citric acid-nitrate method. The results of X-ray diffraction show the peak intensity of both of attapulgite and CeO₂ reduce and the peaks of CeO₂ widen apparently.Meanwhile,the specific surface area of composite powder reduced by about 20%, hole volume reduced by about 19 percent, but the average pore size unchanged. It indicates that the process of composition realize the attapulgite coated by CeO₂, which induce to the the surface activity be reduced,thereby the tendency of powder reunions is weakened.The friction performance of attapulgite powder and attapulgite/CeO₂ composite powder have been evaluated.Experimental results show that attapulgite powder and attapulgite/CeO₂ composite powder have excellent friction-reducing property, friction coefficient of modified attapulgite reduces by 37% than basic oil’s,and that of attapulgite/CeO₂ composite powder reduces by 24.6%.Meanwhile,the oil liquid temperature,power dissipation and shock noise are all lower and more stable than that of basic oil.Attapulgite’s good friction-reducing property is concerned with its layered structure.Attapulgite/CeO₂ composite powder not only inherit attapulgite’s friction-reducing property,but also extrude the polishing and catalysis performance of CeO₂, the carbon-rich film（DLC） can be formed to improve the hardness,wear resistance and fatigue strength of the friction pair face.