机械密封橡胶/金属高压密封界面微动损伤机理与控制研究

The fretting damage failure on the sealing interface of rubber/metal has become an important factor restricting the development of high-reliability of mechanical seal. This study mainly focuses on the key and common issue in mechanical seal-the fretting damage failure, which usually exists on the sealing interface of rubber/metal in auxiliary seal. The fretting damage on the contact interface between the auxiliary seal ring and it's counterpair for mechanical seal was investigated systematically by fretting tribological theory. Through simulating the real friction and wear condition for the auxiliary seal ring against it's counterpair and based on material of friction pairs, displacement amplitude, frequency, contact load, compression ratio, number of cycles, operating environment (e.g. high-pressure, media) and so on, the interaction and relationship between the test parameters, environment, damage morphology and extent were discussed by analyzing the running condition fretting map, damage morphology, wear volume and so on in detail, to develop the failure model of fretting damage and to discuss the fretting damage mechanism and control method for the sealing interface of rubber/metal. so as to provide the theoretic dependence of tribological design for further constructing the mechanical seal system with high reliability. Also, it will be helpful to mitigate problem on the fretting damage failure of the sealing interface of rubber/metal for mechanical seal and to extend its application field.

橡胶/金属密封界面的微动损伤失效制约了机械密封技术向高可靠性发展。本项目针对机械密封的关键共性问题-橡胶/金属密封界面微动损伤失效，提出运用微动摩擦学理论，系统地对辅助密封圈接触界面间的微动损伤进行理论分析和试验研究，通过模拟密封圈与对磨副间的摩擦磨损，从配副材料、位移幅值、运动频率、接触载荷、压缩率、循环周期以及运行环境（如高压、介质）等方面入手，通过微动运行工况图、损伤形貌、磨损量等指标的详细分析，探讨试验参数、运行环境、损伤形貌及损伤程度之间的相互作用和内在联系，建立橡胶/金属密封界面的微动损伤失效模型，探讨橡胶/金属密封界面的微动损伤机理和控制方法。本研究不仅可以为进一步构建高可靠性的机械密封系统提供摩擦学设计的理论依据，同时对减缓机械密封橡胶/金属密封界面微动损伤失效、拓展机械密封的应用领域等方面具有重要的意义。

密封技术的可靠性和稳定性已成为现代流程工业设备安全、稳定运行的关键因素。橡胶动密封广泛应用于航空航天、交通运输、工程机械、石油石化、制药装备等领域的液压密封、气动密封以及机械密封的辅助密封等。密封件工作时，普遍存在摩擦、磨损、密封和润滑等基本问题，橡胶/金属摩擦副可能出现相对静止、不连续滑移、部分滑移和完全滑移等复杂的接触状态，势必引起橡胶/金属接触副间微动的产生，进而制约了机械密封技术向高可靠性发展。本项目针对机械密封的关键共性问题—橡胶/金属密封界面微动损伤失效，基于微动摩擦学理论分析微动运行行为、损伤形貌、磨损量等指标，探讨试验参数、运行环境、损伤形貌及损伤程度之间的相互作用和内在关联，建立橡胶/金属密封界面的微动损伤失效模型，揭示机械密封辅助密封圈及其配副材料密封界面的微动损伤机制。主要研究成果包括：(1) 采用含高阶项的 Mooney‐Rivilin本构模型对密封用 O 形丁腈橡胶圈进行了轴对称有限元分析，揭示了位移幅值、介质压力、压缩率及摩擦系数对其微动特性的影响机制；(2) 完成了 O 型密封圈夹具系统的改造，利用UMT-3摩擦磨损试验机进行橡胶 O 形圈的微动摩擦磨损试验，再现了密封圈接触界面的微动损伤。同时，选取典型配副材料考察位移幅值、运行周期、接触载荷、压缩率、材料匹配及其表面粗糙度等因素对微动损伤的影响规律；(3) 揭示了 O 型圈在微动作用下的运行行为、磨损机理及其损伤演变规律，建立了橡胶/金属密封界面的微动运行工况图; (4) 此外，研究发现了橡胶/金属摩擦配副最佳表面粗糙度参考范围，揭示了不同表面粗糙度下橡胶表面的损伤机制，研制了可以有效减缓橡胶/金属的黏着的石墨烯涂层，提出了有效控制密封界面抵抗摩擦磨损的若干方法。本项目不仅可以为进一步构建高可靠性的橡塑密封系统提供摩擦学设计的理论依据，而且对解决机械密封微动摩擦界面乃至橡塑密封界面的摩擦磨损失效、拓展橡塑密封的应用领域等方面具有重要的意义。