高超声速飞行器可变流道超高温平面滑动密封结构制造基础研究

Ultra-high temperature plane sliding seal directly determines the efficiency of variable cross-section ramjet engine, which is a key technical problem to be solved urgently in the development of hypersonic vehicle. Based on the high temperature, strong vibration and thermal shock, the design and manufacture of key parts of sliding seal based on high strength and tough ceramic matrix composites were studied in this paper. This project mainly introduces the establishment of dynamic multi - field coupling model, studies the working principle of grid plate sliding seal under the harsh working conditions, and proposes a collaborative design and manufacturing method for the characteristics of high strength and tough ceramic matrix composites. We will study the modification of self-lubricating system material to improve the friction and wear properties of ultra-high temperature grid plate seal, and the principle and method of preparing high-deformation large-deformation ceramic elastic element by high strength fiber combined with chemical vapor infiltration. We also will study the design method of precision structure of ultra-high temperature dynamic seal and the performance evolution and stripping mechanism in the process of coordination between ceramic phase and toughening. Finally, the principle and method of the performance test of the typical plane sliding seal assembly test are proved, which provides theoretical and practical support for the design and manufacture of the critical ultrafast temperature dynamic sealing parts of the hypersonic vehicle.

超高温平面滑动密封直接决定变截面冲压发动机的效能，是高超声速飞行器研制中亟待解决的关键技术问题。以高超声速飞行器可变流道用超高温栅板式平面滑动密封为研究对象，针对其超高温、强振动、热冲击等严酷工作环境，研究基于高强韧陶瓷基复合材料的动密封关键零件设计制造基础问题。主要包括：建立动态多场耦合模型，研究栅板式平面滑动密封在上述苛刻工况条件下的工作原理，提出面向高强韧陶瓷基复合材料特性的协同设计和制造方法。研究自润滑体系材料改性以提高超高温栅板式密封摩擦磨损性能，及通过高强韧纤维结合化学气相渗透制备耐高温大变形陶瓷弹性元件的原理和方法。研究超高温动密封精密结构设计方法及陶瓷相和增韧相协调加工过程中的性能演变规律和剥离机制。最终通过典型平面滑动密封组件性能试验验证课题得出的原理和方法，为高超声速飞行器关键性超高温动密封零件设计制造提供理论和实践支撑。

超高温平面滑动密封直接决定变截面冲压发动机的效能，是高超声速飞行器研制中亟待解决的关键问题之一。本项目针对流道超高温、强振动、热冲击的环境特点，研究了基于陶瓷基复合材料的超高温栅板式平面滑动密封设计制造过程中的基础问题：1）建立平面滑动栅板密封的多场耦合模型，面向陶瓷基复合材料制造过程完成密封结构协同设计，获得了密封结构制造关键参数；2）研究高温自润滑异型栅板密封件和高弹大变形弹性元件成型工艺及表面精密结构加工工艺，阐明材料微观演变规律和剥离机制，探索加工工艺改进方法；3）研究密封结构装配工艺及性能测试方法，获得了高温陶瓷弹性元件特性和陶瓷摩擦副的摩擦磨损特性，试验验证高温栅板密封特性理论算法，获得了密封基本工作性能，为超高温动密封的研制提供理论依据和试验数据支撑。