【摘要】 根据二维编织C/SiC复合材料的细观结构及其制备工艺特点,提出了一种预测该材料热传导系数的单胞模型。模型简化了编织结构纱线的实际构型,充分考虑了编织结构复合材料由于化学气相渗透(CVI)工艺制备陶瓷基复合材料产生的孔洞对热传导系数的影响。利用单胞模型预测了二维编织C/SiC的结构参数、纤维体积含量、孔洞体积含量对复合材料热传导系数的影响规律。结果表明:随着纤维束扭结处产生间隙与纱线宽度比值的增大,热传导系数减小;当其它参数不变时,热传导系数随着纤维体积含量和孔洞体积含量的增加而下降。利用Hot Disk热测量仪采用瞬变平面热源法测试了二维编织C/SiC复合材料面内的热传导系数,试验结果与模型预测结果吻合较好。更多还原

【Abstract】 A unit cell model based on meso-structure and fabrication procedure was presented for the in-plain coefficient of thermal conductivity for 2D braided C/SiC composites.In this unit cell model,the actual strand cross-section geometry was simplified and the void caused by the possible gap between two adjacent strands was taken into account.The influence of structure parameters on the 2D braided C/SiC composite’s coefficient of thermal conductivity was predicted.The predicted results show that the composite’s coefficient of thermal conductivity decreases with the increase of kinking distance,as well as,decreases with the increase of fiber volume fraction and void volume fraction.The test result shows that there is a good correlation between the predicted results and the experimental values.更多还原