论文部分内容阅读
对不同直径圆柱预制体的CVI增密过程进行数值模拟研究,分析预制体尺度对增密过程及密度分布的影响。针对高90mm,直径分别为60、120、180mm的预制体,分别模拟CVI过程中预制体的孔隙率、密度以及孔隙平均尺寸分布和变化特征。结果显示,小直径预制体经过一段时间的沉积后密度分布较为均匀,且平均密度值很高;预制体直径较大时,沉积易发生在表面区域,导致表面区域密度较高,中心区域密度值较低,影响进一步的增密过程。
The numerical simulation of CVI densification process for prefabricated cylinders with different diameters was carried out. The influence of preform size on densification process and density distribution was analyzed. For prefabricated body with height of 90mm and diameter of 60,120,180mm respectively, the porosity, density and average pore size distribution and variation characteristics of preform in CVI process were simulated respectively. The results show that the density distribution of the small diameter preform after a period of deposition is more uniform and the average density is very high. When the diameter of the preform is larger, the deposition tends to occur in the surface area, resulting in a higher density of the surface area. The density of the central area Lower, affect the further enrichment process.