纳米CeO₂、TiO₂粒子组合物用作润滑油添加剂的摩擦学性能和机理研究

【作者】 李磊；

【导师】 顾卓明； 顾彩香；

【作者基本信息】 上海海事大学 ， 轮机工程， 2007， 硕士

【摘要】 近年来随着经济的增长,我国的润滑油以及润滑油添加剂的需求量在逐年递增,而且对润滑油的品质要求也越来越高,传统意义上油溶性添加剂越来越无法满足我国工业发展的需要;另一方面人们的环保意识也在逐渐提高,传统的润滑油添加剂由于含有硫、氯、磷等污染环境的元素,所以这些添加剂也逐渐被划入淘汰者的行列。同时常规微米数量级的无机粒子在润滑油中的分散性较差,并且会对摩擦副表面造成损坏,因此也严重制约了这些添加剂的广泛应用。因此,面对这种情况,各个润滑油公司、科研机构和大中专院校都在努力寻找新的突破点。随着纳米技术的出现和应用,纳米润滑添加剂为解决这一难题带来了新的希望。本文选用了适当的纳米CeO₂和TiO₂粒子,经过对纳米粒子表面改性后将其加入到基础油中,并在四球磨损试验机上对纳米CeO₂、TiO₂粒子及其粒子组合物作为润滑油添加剂的摩擦学性能进行了测试,最后探讨了这些纳米粒子用作润滑油添加剂的抗磨减摩作用机理。本文主要结论如下;1.采用X-线衍射仪（XRD）和透射电子显微镜（TEM）测定了纳米CeO₂和TiO₂粒子的晶体结构、粒径大小和晶体形貌,测定结果为;纳米CeO₂粒子呈球形,平均粒径为10.4nm;纳米TiO₂粒子呈颗粒状,平均粒径为15.2nm。2.根据亲水亲油平衡值（HLB）,选用了Tween-20、Tween-60、Span-20和十二烷基苯磺酸钠作为纳米CeO₂和TiO₂粒子的表面活性剂,并且按照质量比为2;2;1;1进行配制时,该复合表面活性剂对纳米CeO₂和TiO₂粒子具有较好的分散稳定效果。3.在磨损试验机上对纳米CeO₂、TiO₂粒子以及粒子组合物用作润滑油添加剂的摩擦学性能进行了测试,试验表明纳米粒子作为润滑油添加剂能明显提高润滑油的最大无卡咬负荷P_B值、减小磨斑直径WSD和降低摩擦因数μ。4.纳米CeO₂、TiO₂粒子组合物添加剂的最佳添加量为;Wt_CeO2;Wt_TiO2=1;3,总质量分数为0.6%左右。5.通过对所配制润滑油油样、钢球磨斑形貌观察和实验数据的分析,可知表面活性剂将纳米CeO₂粒子和纳米TiO₂粒子包围形成了“微胶粒”,从而使纳米粒子在润滑油中得到了良好的分散,并且使得纳米润滑油稳定性相对较好;同时还发现纳米CeO₂粒子对纳米TiO₂粒子在润滑油中的团聚具有良好的抑制作用,并可以适当减少纳米TiO₂粒子的使用量。6.通过采用TEM分析、XRD分析、SEM分析等现代测试手段,从纳米粒子的晶体结构、晶粒大小和磨斑形貌等处着手,探讨了纳米CeO₂、TiO₂粒子用作润滑油添加剂可能的抗磨、减摩作用机理,提出了自己的观点。主要机理有;（a）“微抛光”作用机理;（b）“微滚珠”作用机理;（c）“填充修复”作用机理;（d）协同作用机理。本课题所开展的工作是“纳米技术在润滑油中的应用”研究领域的探索性工作,是上海市教委科研项目“纳米材料润滑油添加剂产业化应用的关键技术研究”（05FZ31）和“纳米润滑油添加剂在发动机中的应用研究”（06FZ008）中的一部分,大量的工作和验证还有待今后继续深入研究。更多还原

【Abstract】 As the development of our economy,our country is needing more and more high quality lubricanting oils and lubricanting oil additives.The traditional oil-soluble anti-wear and friction-reducing additives which contain harmful elements such as sulfide,chlorine and phosphorus have not met the needs of development of modern industry for the poor qualities of lubricant products and rising consciousness of environment protection.So they will be fallen into disuse. The routine micron inorganic particles can抰be dispersed in the oil,and can scratch the working surfaces,so they are not be used widely.In this condition, many lubricant companies,academes and college schools are searching new breaks to meet the needs.As the development of nanotechnology,nano-lubricant additives will give a bright future of resolving the problems well.In this paper,nano-particles of CeO₂ and TiO₂ were selected appropriately,the surfaces of nano-particles of CeO₂ and TiO₂ were modified with surfactants,nano-lubritanting oils were prepared by putting nano-particles of CeO₂ and TiO₂ into base oil,the nano-lubricanting oils were tested on a four-ball tribotester and the anti-wear and friction-reducing mechanisms of nano-particles of CeO₂ and TiO₂ as lubricanting oil additives were studied with modern testing tools.The main conclusions are following;1.The crystal structure and average sizes of nano-particles of CeO₂ and TiO₂ were tested by a X-ray Diffractometer.And the morphologies and average sizes of nano-particles of CeO₂ and TiO₂ were measured with a Transmission Electron Microscope.The results indicated that nano-particles of CeO₂ whose diameters are about 10.4nm appeared as spherical powders and nano-particles of TiO₂ whose diameters are about 15.2 nm appeared as granular particles.2.On the basis of HLB values,suitable surfactants such as Tween-20, Tween-60,Span-20 and sodium sodecylbenzenesulfonate were selected to modify the surfaces of nano-particles of CeO₂ and TiO₂.The results indicated that nano-particles of CeO₂ and TiO₂ have the good dispersion and stability in the lubricating oils after modification when the qualitatively proportion of surfactants is 2;2;1;1.3.Tribological properties of nano-particles of CeO₂ and TiO₂ as lubricanting oil additives were tested on a four-ball tribotester.The results implied that nano-additives of CeO₂ and TiO₂ can improve the tribological properties of the lubricating oils by rising P_B and reducing WSD andμ.4.The optimal proportion of nano-additives of CeO₂ and TiO₂ as lubricanting oil additives is Wt_CeO2;Wt_TiO2=1;3,and the content is about 0.6%。5.Through observing the examples of nano-lubricanting oils and the morphologies of the worn steel balls and analyzing experimental datum,the results could imply that the compound surfactants encircled the nano-particles and they formed many microcapsules in the lubricating oil,so the nano-particles of CeO₂ and TiO₂ could disperse well and not reunite again.It might also be that nano-particles of CeO₂ could restrain the reunification of nano-particles of TiO₂.6.By using modern testing tools,such as TEM,X-ray diffractometer and SEM, the mechanisms of anti-wear and friction-reducing of nano-particles of CeO₂ and TiO₂ as lubricanting oil additives were discussed according to crystal structures, sizes of nano-particles and the morphologies of worn steel balls.Some mechanisms could be揗inute Ball Bearing Effect Mechanism?揗inute Polishing Effect Mechanism?揊illing and Repairing Effect Mechanism ?and搕he Compound Effect Mechanism?This paper was a groping study of揘anometer Material抯Application in Lubricanting Technology?and it is one part of揜esearch on the Key Techniques of Industrialization of Nanometer Materials as Lubricanting Oil Additives（05FZ31）" and揜esearch on Nanometer Material抯Application in Engine Lubricanting oil （06FZ008）?of Shanghai Scientific and Technological Committee.More research works are expected to be further developed.更多还原