高精度陀螺仪表关键零组件材料稳定性研究及调控机理

The present investigation mainly focuses on the 2024Al alloy, beryllium (Be) and instrumental grade SiC/Al composites, which have been used in key components ofhigh precision gyro instruments. Based on the simulation of the service and long-term storage condition of gyro instruments, their dimemsional stability under multi-fields (temperature, stress and time fields) would be comprehensively invesitated, and the coupling effect of multi-fields and corresponding mechamism would be revealed. Meanwhile, the microstructure envolution process (microstructure of dislocations, precipitates, grain size and orientation, and macro- and micro-stress) during the coupling effect of multi-fields would be clarified. Moreover, the constitutive equation for micro-creep under the coupling effect of multi-fields could be derived. Furthermore, stress relaxation models under the coupling effect of multi-fields would be established, and the corresponding dimensional stability would be deeply discussed, which is beneficial for the enrichment and development of micro-deformation theory of metal materials. Based on the above investigation, the microstructure control techniques (such as isotropic thermomechanical and stabilization treatments, etc.) for high dimensional stability would be explored and eventually realized. Through simulation, the thermal stress field of gyro instruments’ components under coupling effect of multi-fields would be quantitatively described, which could be tested and verified by comparing with the experimental dimensional evolution results. Eveltually, the relationship between the gyro instruments’ precision and the dimensional stability of materials would be discussed, and material mechanism of the successive drift behavior of gyro instruments would be revealed, establishing theorical foundation for the improvement of the precision and stability of gyro instruments.

以高精度陀螺仪关键材料2024Al合金、Be材和仪表级SiC/Al复合材料为主要研究对象，模拟陀螺仪服役条件和长期贮存条件，系统研究温度场、应力场和时间多场耦合作用下的材料尺寸稳定性行为，揭示多场耦合规律和作用机制；研究多场耦合作用下位错结构、第二相析出、晶粒取向与尺寸、宏微观应力的演化规律；构建多场耦合作用下微蠕变的本构方程；揭示多场耦合下的尺寸稳定性微观机制，进一步丰富和发展金属的微形变理论；在此基础上，探索高尺寸稳定性的微观结构调控方法，通过各向同性化形变热处理、稳定化处理等手段，实现对仪表材料的显微组织调控；通过计算机模拟，定量描述多场耦合下的陀螺零组件的热应力场，并通过陀螺组件尺寸变化规律检测验证计算结果；建立仪表精度与材料稳定性相关规律，揭示精密仪表材料精度逐次漂移的材料学原理，为高精度陀螺仪精度及其稳定性提高奠定理论基础。

本项目以提高陀螺仪精度及精度稳定性为需求牵引，通过模拟贮存、多次启动、大过载等服役环境，研究了铝合金、铍材和仪表级SiC/Al复合材料尺寸变化机制，回答了引发惯性仪表精度漂移的材料学原因。研究了2024Al铝合金的尺寸稳定性，揭示了由织构引发的尺寸变化各向异性机理，提出了消除织构各向异性的形变热处理方法，为改良现役仪表用铝合金的尺寸稳定性提供理论指导。研究了国产Be-1铍材的尺寸稳定性，明确了第二相长大是引发微塑性变形的主要原因，提出了改善铍材的尺寸稳定化方法，为铍材在惯性仪表中的进一步应用提供基础数据。研究了仪表级复合材料的尺寸稳定性，阐明了由基体内禀拉应力引起的尺寸变化机制，制定了基体合金化+热处理的组织调控工艺路线，为复合材料在惯性仪表中的更新换代提供了理论基础和工艺支撑。与中国航天科技集团九院16所密切协作，验证了三类仪表材料组织调控工艺的正确性，突破了仪表级复合材料高精度复杂薄壁构件加工工艺，并加工装配了国内第一台仪表级SiC/Al复合材料三浮陀螺仪样机，正在开展装机测试。本研究为陀螺仪精度及精度稳定性提升奠定了材料学基础，优化的仪表级复合材料正式批产应用于25个武器型号的惯性器件、红外光学、激光通信等高精度装备。