摘要
采用化学气相渗透工艺制备平纹SiC/SiC复合材料,利用X射线CT无损检测技术研究纺织陶瓷基复合材料拉伸损伤演化与失效机理.制备了第3代SiC纤维增韧平纹叠层SiC/SiC狗骨状试件.研制了CT原位拉伸测试仪,完成了纳米X射线CT原位拉伸试验,对CT扫描三维重建图像和扫描电镜照片进行了分析.结果表明:纳米X射线CT原位试验能够揭示材料拉伸损伤演化过程.平纹SiC/SiC复合材料单轴拉伸应力-应变曲线呈现明显的非线性特征,损伤萌生于非线性变化阶段.首先,出现基体横向开裂,并随着拉力的增加逐渐扩展.其次,出现层间基体开裂和纤维束基体纵向开裂,并逐渐扩展至纤维束宽度.最后,拉伸方向纤维断裂,材料失效,大多基体横向裂纹闭合,但纵向纤维束与束间基体分离严重,断口参差不齐,有明显的纤维拔出现象.
Plain weave SiC/SiC composites were manufactured by the chemical vapor infiltration process,and X-ray computed tomography non-destructive testing technology was used to investigate the damage evolution and failure mechanism of textile ceramic matrix composites.Besides the third generation SiC fiber toughened plain weave laminated SiC/SiC dog bone test pieces were prepared.In addition,a CT in-situ tensile tester was developped,the nano in-situ X-ray CT tensile tests were completed,and the three-dimensional reconstruction images and scanning electron microscope photos of CT scans were analyzed.The results show that nano X-ray CT in-situ tests can reveal the evolution of tensile damage of materials.The uniaxial tensile stress-strain curve of plain weave SiC/SiC composites exhibits obvious nonlinear characteristics,with damage initiating in the stage of nonlinear changes.First,lateral cracking of the substrate occurs and gradually expands with increasing tensile force.Next,interlayer matrix cracking and fiber bundle matrix cracking occur longitudinally and gradually expand to the fiber bundle width.Finally,the fiber in the tensile direction breaks and the material fails.Most of the substrates have transverse cracks closed,but the longitudinal fiber bundles and the matrix between the bundles are severely separated,the fractures are uneven,and there are obvious fiber pull-outs.
作者
刘海龙
张大旭
祁荷音
伍海辉
郭洪宝
洪智亮
陈超
张毅
LIU Hailong;ZHANG Daxu;QI Heyin;WU Haihui;GUO Hongbao;HONG Zhiliang;CHEN Chao;ZHANG Yi(School of Naval Architecture,Ocean and Civil Engineering,Shanghai Jiao Tong University,Shanghai 200240,China;Aero Engine Corporation of China Commercial Aircraft Engine Co.,Ltd.,Shanghai 201180,China;Science and Technology on Thermostructural Composite Materials Laboratory,Northwestern Polytechnical University,Xi’an 710072,China)
出处
《上海交通大学学报》
EI
CAS
CSCD
北大核心
2020年第10期1074-1083,共10页
Journal of Shanghai Jiaotong University
基金
国家自然科学基金(11272207,U1831105)
上海市科学技术委员会科研计划(15DZ1161100)资助项目。
关键词
复合材料
原位试验
缺陷
损伤演化
失效机理
composite
in-situ test
defect
damage evolution
failure mechanism
