先驱体转化-热压单向C_f/SiC复合材料的高温弯曲力学行为  

BENDING BEHAVIOR OF UD-C_f/SiC COMPOSITES PREPARED BY PRECURSOR PYROLYSIS AND HOT PRESSING AT ELEVATED TEMPERATURES

作　　者：曹英斌[1] 张长瑞[1] 周新贵[1] 陈朝辉[1] 

机构地区：[1]国防科技大学航天与材料工程学院先进陶瓷纤维及其复合材料国防科技重点实验室,长沙410073

出　　处：《硅酸盐学报》2001年第5期435-438,共4页Journal of The Chinese Ceramic Society

基　　金：国防预研重点资助项目 ( 12 .1.4.3)

摘　　要：研究了采用先驱体转化 -热压烧结制备的单向Cf/SiC复合材料室温 ,15 73,172 3,192 3K温度下力学行为 ,并从显微结构的特征分析了单向Cf/SiC复合材料高温力学行为的变化原因 .结果表明 :Cf/SiC复合材料的室温 ,15 73,172 3 ,192 3K温度下弯曲强度分别为5 5 0 ,392 ,394,5 74MPa ,弯曲模量分别为 15 7,14 8,132 ,83GPa .Cf/SiC复合材料破坏时 ,其破坏方式将从室温和 15 73K的分层断裂向172 3K ,192 3K的脆性断裂转化 .Cf/SiC显微结构的分析表明 ,在纤维周围和大晶粒间存在着大量的有一定结晶程度的玻璃相 。The bending behavior of C f/SiC composites prepared by precursor pyrolysis and hot pressing was studied at temperatures from RT to 1 973 K. The changes of the mechanical behavior at different temperatures were explained by the changes in microstructure. The results show that the UD_C f/SiC composites′ bending strength and modulus at RT, 1 573, 1 723, 1 923 K are 550, 392, 394, 574 MPa and 157, 148, 132, 83 GPa, respectively. The fracture behavior changes from delaminating mode at RT and 1 573 K to brittle mode at 1 723 K and 1 923 K. It is found from the HRTEM images that there are a glass layer in the fiber/matrix interface and the interface between SiC powders. The softening of the glass layer at high temperature will strongly influence the high temperature mechanical behaviors of the C f/SiC composites.

关 键 词：碳纤维增强 碳化硅复合材料 高温 力学性能 显微结构 先驱体转化 热压 陶瓷基复合材料 

分 类 号：TQ174.15[化学工程—陶瓷工业] Q174.758[化学工程—硅酸盐工业]