C/C复合材料等温CVI工艺T-S模糊系统研究

等温CVI是目前制备高性能碳／碳(C／C)复合材料的重要技术,其主要不足之处是周期长,成本高,建立CVI工艺参数与沉积速率或均匀性之间的关系模型,进而来指导工艺的设计与优化,是达到降低C／C复合材料开发成本的重要途径。本文提出基于模糊推理系统理论,建立等温CVI工艺基于实验的T—S模糊系统模型,来挖掘和表达实验中所积累的无法用公式来描述的经验,根据该模型得到了一类盘状制件CVI工艺主要沉积条件的作用机理,为工艺优化、设计和控制提供了理论上的指导。

T-S fuzzy system for isothermal CVI process of C/C Composites

Isothermal CVI is one of the most important conventional techniques for the manufacture of C/C composites,because C/C composites fabricated by isothermal CVI possess some excellent properties and the isothermal CVI process which with a good parameter control utilizes relatively simple equipment.The isothermal CVI process,however,is a lengthy technical procedure with a high cost.The model of relation between densification rate or uniformity and the CVI process parameters should be built to guide the optimization of CVI process,and this is an important way of decreasing the fabricating cost of C/C composites.Unfortunately,the CVI process is influenced by so many factors that it cannot be easily and precisely modeled by "first principles" methods.In this paper,an experimental T-S fuzzy system model for isothermal CVI process was proposed based on the theory of fuzzy inference system,and this model was used to mine and express the experience that cannot be expressed by formulas.From the T-S fuzzy system,the mechanisms of main infiltration conditions had been studied,and in theory,they were good instructions for the optimization,design and control of CVI process.