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Al2O3nanoparticles were prepared by hydrothermal method and calcining method.Using the graft and situ surface modification method to change the surface of thenanoparticles. The optimum process parameters of hydrothermal method: aluminum source:aluminum isopropoxide, KH-560modifier dosage:1.0wt%, PH value:8, hydrothermaltemperature:220℃. In calcining method, the test factors are aluminum source:Al（NO3）3, PHvalue:9, calcining temperature:500℃, modifier dosage:1.5wt%. The structure of Al2O3nanoparticles was characterized by way of instruments analysis such as X-ray diffractionanalyzer, scanning electron microscope, laser particle size analyzer. The dispersion ability ofAl2O3prepared by hydrothermal method are better than calcining method. Al2O3aresuccessfully modified by KH560, which tested by Fourier transform infrared spectra （FT-IR）.CuO nanoparticles were prepared by hydrothermal method. The optimum processparameters: modifier: natrium oleinicum, hydrothermal temperature:150℃, hydrothermaltime:16h. CuO are succesfully modified by sodium oleate, testing through Fourier transforminfrared spectra （FT-IR）. After modified, the size of CuO nanoparticles changed from83nm to65nm and the dispersion ability improved, which are tested by laser particle size analyzer,scanning electron microscope and ZETA anylysis.CuO/Al2O3nanoparticles were prepared by hydrothermal method. The optimumprocess parameters: molar ratio of Al/Cu:1:1, hydrothermal temperature:140℃, modifier:oleic acid, modifier dosage:5.0wt%, PH:5. The CuO/Al2O3are composite nanoparticlescosnsist of CuO, Al2O3, CuAl2O4. The CuO/Al2O3are83nm with good dispersive abilityThe friction reducing and anti-wear behavior of the CuO, Al2O3and CuO/Al2O3nanoparticles used as additive in lubricant oil were analyzed by friction and wear test machineof MMU-10G. the friction coefficient of the samples studied have a biggest friction reductionof33.2%,23.8%,35.6%when0.05wt%of CuO,0.1wt%of Al2O3,0.1wt%of CuO/Al2O3composites were existed in the lubricant respectively. When0.05wt%of CuO,0.1wt%ofpure Al2O3and0.1wt%of CuO/Al2O3composites were existed in the lubricating oil, theWSD reduction were10.3%,36.2%,39.1%respectively. For further study, antifriction andantiwear performance of lubricant dispersed with CuO/Al2O3composites and physicalmixtures of CuO and Al2O3are also investigated. The lubricant dispersed with CuO/Al2O3composites has the best antifriction and antiwear effect by comparison to lubricant withCuONps, Al2O3Nps or physical mixtures of CuO and Al2O3, presenting the Synergistic effect of CuO and Al2O3. It seems that CuO/Al2O3composites has a trend to present Synergisticeffect, while physical mixtures exerting a adduct effect.Through the analysis of friction test, nanoparticles friction-reducing mechanism is asfollows: CuO/Al2O3composites transferred onto the thrust-ring surface together with thelubrication and a protective film was formed during the rubbing process. At the presence ofthe nanoparticles, friction between pairs was changed from sliding friction to rolling frictionwith the nanoparticles as bearings.
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