纳米碳酸钙用作润滑油添加剂的摩擦学性能和机理研究

【作者】 王仁兵；

【导师】 顾卓明； 顾彩香；

【作者基本信息】 上海海运学院 ， 轮机工程， 2002， 硕士

【摘要】 纳米粒子是介于宏观物质与微观原子或分子之间的过渡亚稳态物质，具有小尺寸效应、量子尺寸效应、表面效应与宏观量子隧道效应等，从而表现出一些特殊的性质。将纳米粒子加入到润滑油中，可以提高其极压性能和抗磨性能，减少摩擦阻力，延长机器零部件的使用寿命。本文采用X射线衍射仪和透射电镜检验了纳米碳酸钙粒子的粒径和内部结构，根据亲水亲油平衡值(HLB)，选择合适的表面活性剂将其加入到含有纳米碳酸钙粒子的润滑油中进行表面改性。通过测试最大无卡咬负荷、观察磨斑表面形貌和测定磨斑直径以及测试摩擦系数，对纳米碳酸钙粒子的极压性能和抗磨减摩性能进行了分析和研究；通过XPS测试对纳米碳酸钙润滑油添加剂进行了摩擦化学的分析和研究，对于纳米碳酸钙粒子的抗磨减摩机理做了系统的分析。本论文所做的具体工作及结论如下： 1、介绍了纳米粒子的奇特性能并探讨了纳米材料在润滑技术领域的研究和应用进展。 2、采用先进的仪器对所选择的纳米碳酸钙粒子进行了测定： (1)使用旋转阳极靶多晶X射线衍射仪测定其晶体结构和平均粒径大小。 (2)用透射电子显微镜观察其形貌和测定粒径大小。 3、根据表面活性剂亲水亲油平衡值选择了聚醚、吐温-60、司本-20和司本-80作为纳米碳酸钙粒子的表面活性剂，它们以胶囊的形式存在。结果表明这几种活化剂同时使用产生了很好的协同效应，使得纳米碳酸钙粒子在润滑油中得到了很好的分散性和稳定性。 4、通过测试和分析纳米碳酸钙粒子的摩擦学性能，证明了纳米碳酸钙粒子加到基础油中可以提高基础油的极压性能和抗磨减摩性能。纳米碳酸钙粒子在含量为0.7％左右时摩擦学性能最佳；成品油中加入0.5％的纳米碳酸钙粒子时，抗磨减摩性能效果显著。 5、通过XPS测试，对纳米碳酸钙粒子的摩擦化学性能进行了研究，在摩擦过程中碳酸钙、氧化钙和金属钙共同起到了提高极压性能、抗磨减摩的作用。 6、探讨了纳米碳酸钙粒子的抗磨减摩机理，对于纳米粒子在润滑油中的存在方式和作用提出了个人见解： (1)纳米碳酸钙粒子近似为球形，它们起了类似微型“球轴承”的作用，从而提高了摩擦副表面的润滑性能。 (2)在重载和高温条件下，两摩擦表面间的纳米氧化钙颗粒被压平，形成一滑动系，降低了摩擦和磨损。 （3）摩擦过程中纳米碳酸钙、纳米氧化钙粒子能填平摩擦表面低凹处甚至陷入基体中，并可及时填补损伤部位，具有自修复功能，使摩擦表面始终处于较为平整的状态。 （4）纳米碳酸钙和纳米氧化钙粒子通过摩擦过程中的摩擦化学作用在磨斑表面上形成了沉积膜，少量金属钙通过扩散作用渗透到钢基体表面，形成表面强化层，提高了表面的耐磨性。 本文所做工作是对纳米粒子作为润滑油添加剂性能研究领域的探索性工作，是上海市科委项目“纳米材料用于润滑油剂添加剂的摩擦机理研究”和上海市教委重点基金项目“纳米材料在润滑技术中的应用”中的一部分，大量的工作还需要在今后继续深入研究。更多还原

【Abstract】 The nanometer particles are metastable materials that lie between macroscopical materials and atoms or molecules with the characteristics of little size effect, quantum measurement effect, surface effect and macroscopical quantum tunnel effect, etc., thus demonstrating some special properties. When mixed with the lubricating oil, the nanometer particles can improve lubricating oil’s abilities of extreme pressure, anti-wear and reduce frictional resistance. So the nanometer particles can lengthen the service life of the machine and its parts. By adopting X-ray diffraction and Transmission Electron Microscope (TEM), this thesis has insepectd the size and the structure of the calcium carbonate (CaCO3) particles. According to Hydrophile and Lipophile Balance (HLB), the suitable surface-active agents have been selected and put into lubricating oil with nanometer CaCO3 particles. By testing some parameters, such as the maximum non-seizure load, the shape and diameter of wear scar, the friction factor, the nanometer CaCO3 particles’ properties of extreme pressure, anti-wear and friction reduction have been tested and analyzed. The properties of the nanometer CaCO3 particles’ tribology chemistry have been analyzed through X-ray Photoelectron Spectrum test. Also the nanometer CaCO3 particles’ mechanism of anti-wear and friction reduction has been studied systematically. Specific work and conclusions are as follows:1. This thesis introduces the nanometer particles’ queer characters and discusses the application of the nanometer particles as lubricating oil additive.2. The chosen nanometer CaCOj particles have been tested and analyzed through advanced instruments.1) The crystal structure and average size of the nanometer CaCOs particles have been tested by rotatory anode harrow X-ray diffractometer.2) The shape and average size of the nanometer CaCO3 particles have been tested through TEM.3. On the basis of HLB suitable surface-active agents such as Polyether, Tween-60, Span-20 and Span-80, which exist as capsules, are selected. The results show that they have good concertedness, making the nanometer CaCO3 particles receive very good dispersiveness and stability in the oil.4. The results of the test of the nanometer CaCO3 particles’ tribology property show that it can improve base oil’s properties of extreme pressure and anti-wear and friction reduction. Base oil’s tribology property is the best when the nanometer CaCO3 particles’ content is about 0.7%. The result also shows that the properties of anti-wear and friction reduction are remarkableHIwhen 0.5% content of the nanometer CaCO3 particles are added to the finished oil.5. The results of the test of the nanometer CaCO3 particles’ tribology chemistry through X-ray Photoelectron Spectrum show that the nanometer CaCOs, calcium oxide (CaO) and metal calcium improve the oil’s properties of extreme pressure, anti-wear and friction reduction together.6. The mechanism of anti-wear and friction reduction of nanometer CaCOa has been discussed and individual opinions of the nanometer particles’ existing way and effects have been proposed.1) The shape of the nanometer CaCOs particle is approximate to that of sphericity. Its function is similar to that of the miniature "ball bearing". Thus it improves the lubricating performance of friction pairs.2) Under heavy load and high-temperature conditions, the nanometer CaO particles between two friction surfaces are flattened and form a sliding system. Thus wear and friction are reduced.3) In the course of friction the nanometer CaCOs particles and CaO particles can fill up the concave of the surface and even sink into substrate and fill in the worn position promptly. It shows the nanometer particles have automation to make the friction surface in a comparatively even state.4) Through tribology chemistry function, the nanometer CaCOj and CaO particles form a deposited film on the wear scar’s surface or strengthen the surface through a small amount of metal Ca’s diffusion to improve the fr更多还原