笼形纳米碳包合物作为切削介质的冷却与润滑机理研究

In order to improve the cooling and lubricating effect in the cutting area, the lubricating additives will be filled in the cage-like nano carbon by its filling and modification technology, and a kind of clathrate that has a structure of ‘inner filled and external modified’ will be used as additives of nano-fluid cutting fluid. Compared with traditional cutting fluid, the new fluid will have better cooling and lubrication ability. The clathrates will have better dissolution and can reduce the surface tension of the cutting fluid, so the fluid will be easy to permeate into cutting area, and the additives in the compounds will be released to enhance lubricity. Firstly, the filling mechanism of the clathrates will be analyzed, and the characteristics like filling rate, solubility, thermal stability of the clathrates will be studied, based on which, the preparation process will be established. Secondly, the formulation of the cutting fluid will be designed to investigate the dispersion stability, the permeability and thermal properties, etc. The lubricating property of the nanofluid will also be evaluated by tribo-test, and then the preparation technology of the nanofluid will be optimized. Finally, using technology like high-pressure cooling, MQL, etc., the cooling and lubrication mechanism of the nanofluid will be studied through series of cutting tests, and the inherent influence rule of the surface quality and the tool wear will also be studied. Through this study, a kind of high-performance cutting fluid will be achieved to replace traditional cutting fluid, and a theoretic support for the optimization of cutting parameter will be supplied.

为增强切削区域的冷却与润滑作用，结合纳米碳的填充、修饰技术，提出将润滑添加剂填充到笼形纳米碳（碳纳米管、C60）的空腔中，形成一种“内填充、外修饰”的包合物，再利用它制备纳米流体切削介质（切削液）。与传统切削液比，该纳米流体在切削区域的导热、换热能力将得到明显提升，且包合物能降低液体表面张力，还具有一定溶解性，使切削液更易渗透到切削区域，并在切削力作用下释放润滑剂起增强润滑的作用。首先，分析纳米碳与润滑剂的填充机理，研究包合物的填充率、溶解性、热稳定性等，建立制备工艺。其次，设计切削液的配方，研究其导热性、渗透性、分散稳定性等热物性能，通过摩擦学试验评价其润滑性能，优化切削液的制备工艺。最后，结合高压冷却、MQL等技术，通过系列切削试验，揭示纳米流体的冷却与润滑作用机理，以及其影响表面质量、刀具磨损的规律。通过本研究，有望实现一种可替代传统切削液的高性能切削液，为切削工艺优化提供理论支撑。

提出将各种润滑添加剂填充到碳纳米管、C60等笼形纳米碳的空腔中制备一种“内填充、外修饰”的包合物，并以包合物为添加剂制备纳米流体切削液，利用包合物具有自润滑性，且导热性强的特点，提高纳米流体在切削区域的润滑、换热能力以及渗透性能。本研究为解决切削区域的冷却和润滑问题提供了一种新方案。主要研究成果包括：（1）分别制备了油酸、T321、RC2540与MWCNTs、C60的包合物，并利用红外光谱、热重分析、透射电镜、扫描电镜等手段对复合物进行了表征，揭示填充过程中的驱动力，并对填充率进行了计算。（2）分别利用包合物制备纳米流体，并对纳米流体的分散稳定、导热系数、导电率、表面张力、粘度进行测试，证明稳定、充分分散的条件下，包合物最多可使基液的导热系数提高110%，利用包合物制备的纳米流体具有更高的导热系数、更小的粘度，包合物能更好的提高纳米流体的导电性、润湿性，复合物在基础液中的最佳浓度分别约为0.1%。（3）对纳米流体的摩擦学性能进了测试，并利用X射线光电子能谱、扫描电镜等对摩擦区域进行了分析。证明利用包合物制备的纳米流体的摩擦系数有逐渐减小的趋势，且在不同载荷下，其减摩效果甚至优于润滑添加剂本身。当包合物的浓度为0.1%左右时，纳米流体能够取得较好的减摩、抗磨效果；随着酸化处理时间的增加，包合物纳米流体的减摩、抗磨也越好。（4）利用包合物纳米流体进行实际切削，取得了较好的加工效果，与普通乳化液相比，利用纳米流体在MQL条件下车削加工时的切削力减少15%，切削温度降低25%，工件表面粗糙度值减小16%，刀具耐用度提高了22%。所取得的研究成果在国内外期刊发表（含录用）论文11篇，其中SCI源刊5篇，EI源刊3篇，中文核心期刊3篇，授权发明专利2项。