基于石墨烯强化的多聚磷酸盐高温自适应润滑机理研究

The theory and methodology system is difficult to be established for studying the lubrication mechanism at elevated temperatues. It is due to the rigorous thermal-mechanical effect between contact bodies, which leads to the insufficient capacity in the detection and representation of the lubrication characteristics. The proposed project is based on the previous research work of applicant. The previous results indicate the polyphosphate lubricant presents good self-adaptive lubrication properties at elevated temperatures. However, the self-adaptive lubrication mechanism is worth to be further studied and the durability of this lubricant still needs to be improved at elevated temperatures. In this project, the graphene is introduced to the polyphosphate lubricant as an enhancer for improving the lubrication durability. The strengthening mechanism of graphene in the polyphosphate lubricant is investigated by means of experiment, image recognition and molecular dynamics simulation. The high temperature tribological experiment and application case studies will be carried out with graphene strengthening based polyphosphate lubricant. It is used to investigate the tribological characters and self-adaptive lubrication mechanism for the proposed lubricant, and establish the research methodology system for the liquid-solid suspension lubricant at elevated temperatures. This project is expected to provide a detailed reference for the study of self-adaptive lubrication mechanism and extend the application of liquid-solid suspension lubricant and graphene. It will contribute to the establishment of lubrication mechanism foundation and research methodology system for the proposed lubricant type at elevated temperatures. It will also present a good example for the development of new lubrication materials and corresponding high temperature application technologies.

高温条件下，接触体间由于动态剧烈的热力耦合效应，使得高温界面的摩擦润滑特征难以被检测且研究方法分散，难以形成系统的高温润滑理论及实验研究方法框架。本课题的开展是基于申请人前期对多聚磷酸盐的研究成果，即多聚磷酸盐在高温下具有良好的润滑自适应性，但是其高温自适应润滑机理仍需深入研究，且润滑层耐磨持久性有待进一步提高。本课题将石墨烯作为润滑强化剂引入多聚磷酸盐润滑剂中，采用实验检测、图像识别及分子动力仿真研究石墨烯在多聚磷酸盐润滑剂中的强化机理。在此基础上，开展基于石墨烯强化的多聚磷酸盐润滑剂高温摩擦实验及应用实例研究，探究其高温摩擦学特性及自适应润滑机理，并建立液-固混合悬浊液类高温润滑剂的实验研究方法框架。本项目的研究成果将为液-固混合悬浊液类润滑剂乃至石墨烯的拓展应用以及高温自适应润滑机理研究提供新的思路，形成系统性高温润滑理论及实验研究方法框架，也将有助于新型高温润滑材料的研发与应用。

严苛的使用条件及润滑剂在此条件下自身的不确定性，使得高温润滑机理研究很难形成统一的润滑理论，进而难以解释复杂多变的润滑现象。现有高温润滑剂存在着热稳定性差、耐磨持久性不稳定、不易清理等局限性，导致无法大量稳定应用于工业领域。本课题以石墨烯、多聚磷酸盐、纳米粉、二硫化钼等润滑材料为研究对象，研制了多种可用于不同高温摩擦环境的石墨烯类复合润滑剂，并采用高温摩擦实验、仿真与微观表界面检测方法，开展了石墨烯类高温润滑材料的摩擦学特性研究，探究了高温条件下石墨烯在多聚磷酸盐润滑剂中的强化机理，以及基于石墨烯强化的多聚磷酸盐润滑剂的高温自适应润滑机理。在此基础上，总结了液-固混合悬浊液类润滑剂的高温摩擦润滑实验框架，并开展了在带钢热轧工艺条件、航空发动机微动摩擦润滑条件及钛合金热轧工艺条件下的石墨烯类润滑剂应用验证实验研究，显著降低了摩擦磨损、改善了接触体表面质量并有效抑制了氧化。本课题研究成果有望为高温金属塑性加工、高温轴承、高温发动机等高温接触界面润滑领域的应用带来良好的经济及社会效益。