Synthesis And Anti-wear Properties Of Nano-additives

Nano-particle as additive in the lubrication is a new application due to its special properties. Now many kinds of nano-particles have been prepared and tested as additives of lubrication. The working theory is different to the scale. In the paper, The methods of how to prepare the Ni and NiO nano-particles are discussed.In this paper, the synthesis of nickel nanoparticles by reduced and hydrothermal methods are researched. And also, the anti-wear properties of nickel nanoparticles are studied. The synthesis of nickel nanoparticles is studied by hydrazine reducing nickel chloride in ethylene glycol at 60 ℃ without any surfactant. The product is characterized to be spheroid and the mean diameter is about 10 nm. The factors such as temperature, amount of NaOH, mol ratio of N2H5OH and Ni2+ influencing on the Ni nanoparticle's mean diameter are studied. The results show that the change of reaction time is consistent with the change of nickel nanoparticles' mean diameter mostly. When using hydrothermal method, the optimized condition is gained but the products agglomerate and the diameter of nickel nano-particle is bigger than reduced method. Add 4%(wt) nickel nanoparticles' solution(Ni: 3wt%) in the 500SN oil, the WSD reduced 35%. If add 4% 80nm nickel nanoparticles' solution, the Pb value will increas 29.4%.The NiO nanoparticles are prepared by two depositing methods. One is using NH3·H2O as depositing solvent, and the mol ratio of Ni2+/NH3-H2O is 1:1.3-1:1.5 to prepare the Ni(OH)2. Then it is to calcine at 400 ℃ for 2-4 hours. The NiO nano-particle produced by this method is about 30-50nm.The effects of reaction time, the mol ratio of materials, the calcined temperature and time on the diameter of NiO are all studied. The other depositing method is using CO(NH2)2 as precipitator. When Ni2+:CO(NH2)2(mol ratio) is 1:4, the materials react at 90-94 ℃ for 2-3 hours to prepare Ni(OH)2, The diameter about 20-30nm of NiO is received to calcine Ni(OH)2 at 400 ℃ for 2-3 hours. Besides materials' mol ratio and reaction temperature, the reaction time and calcined temperature working on the NiO diameter are also studied. Compare with the first method, the products of the second method are more like a sheet. When add 0.25% NiO(30-50nm) to 500SN oil, the WSD will reduce 7.7%. Add the same amount of NiO(30-50nm) to 150SN base oil, the PB value will increase 9.1%.