连续纤维增韧陶瓷基复合材料的环境性能模拟

连续纤维增韧碳化硅陶瓷基复合材料(ceramic matrix composite-SiC,CMC-SiC)是近年来迅速发展的一种新型低密度热结构材料,在高推比航空发动机、高比冲火箭发动机、冲压发动机和防热结构一体化材料等方面具有广阔的应用前景。航空航天器超常服役环境对材料的环境性能提出十分苛刻的要求,通过试车和试飞考核材料耗时、耗资,难以满足材料研制需求,发展科学高效的材料环境性能实验模拟和计算机模拟技术是国际研究的热点,也是材料优化设计的基础。本文介绍了基于“相似理论“建立的与航空发动机环境具有等效性的环境实验模拟平台和风洞模拟平台。利用该实验模拟平台研究了热物理化学因素与复杂应力因素耦合条件下CMC-SiC环境性能演变失效规律。基于计算热力学、分子模拟和因素分析法等理论与方法,初步建立了CMC-SiC相应的环境性能计算机模拟系统,揭示了材料的环境性能演化规律及其微观机制。

ENVIRONMENTAL PROPERTIES SIMULATION FOR CONTINUOUS FIBER-REINFORCED CERAMIC MATRIX COMPOSITES

Continuous fiber reinforced silicon carbide ceramic matrix composites (CMC-SiC) are a new type of thermostructural material with low density,which has developed quickly in recent years for application in aeroengines with high thrust to weight ratio, rocket engines with high impulse to mass ratio,advanced ramjet engines and thermal protection systems.The extreme service conditions in aerospace planes require advanced materials.It is very expensive and time-consuming to evaluate such materials by either ground or flight tests.Developing simulated environment testing facilities and computational techniques for optimization design of materials is an attractive solution to this problem.Two simulated aeroengine environments testing systems,i.e.,a simulated equivalent environment system (ES) and a wind tunnel environment system (WS),was developed based on the similitude theory.The effects of thermal physicochemical factors and complex stress factors on the environmental behavior of CMC-SiC can be investigated in these facilities.Additionally,a computer simulation system has been developed based on thermodynamics,molecular simulation and the factorization method.The evolution of the properties of CMC-SiC and of the microscopic mechanisms can be investigated as well.