Dynamic tensile behavior of two-dimensional carbon fiber reinforced silicon carbide matrix composites
Dynamic tensile behavior of two-dimensional carbon fiber reinforced silicon carbide matrix composites
复制标题
二维碳纤维增强碳化硅基复合材料的动态拉伸行为
DOI：
10.1016/j.msea.2011.05.053
复制
发表时间：
2011-08-25
期刊：
影响因子：
6.4
通讯作者：
Li Yulong
中科院分区：
文献类型：
--
作者：
Chen Xuan;Li Yulong
采用分离式Hopkinson拉伸杆和电子万能试验机分别对二维碳纤维增强碳化硅基（2D-C/SiC）复合材料的动态和准静态拉伸行为进行了研究。结果表明，在高应变速率下，2DC/SiC复合材料的拉伸强度得到了提高。此外，涂层试样不仅表现出15%的抗拉强度的改善，但提高应变速率敏感性相比，未涂层的。拉伸破坏应变对应变率不敏感，保持在0.4%左右。动态加载下的失效试样的宏观光学照片显示锯齿状的断裂表面，其特征在于分层和裂纹偏离，以及明显的纤维拔出/分裂，与准静态加载下的光滑断裂表面形成对比。动态加载下的断裂表面的扫描电子显微镜显微照片清楚地显示出集成束拔出，这意味着抑制束内脱粘和增强束内界面强化，在准静态加载下的广泛的束内脱粘相比。因此，我们认为，对于20 C/SiC复合材料，束内界面的应变率敏感性是主要负责的应变率敏感性的拉伸强度。(C)2011 Elsevier B. V.保留所有权利。
An investigation has been undertaken to determine the dynamic and quasi-static tensile behavior of two-dimensional carbon fiber reinforced silicon carbide matrix (2D-C/SiC) composites by means of the split Hopkinson tension bar and an electronic universal test machine respectively. The results indicate that the tensile strength of 2D C/SiC composites is increased at high strain rate. Furthermore, coated specimens show not only a 15% improvement in tensile strength but heightened strain rate sensitivity compared with uncoated ones. It is also shown that the tensile failure strain is strain rate insensitive and remains around 0.4%. Optical macrograph of failed specimens under dynamic loading revealed jagged fracture surfaces characterized by delamination and crack deviation, together with obvious fiber pull-out/splitting, in contrast with the smooth fracture surfaces under quasi-static loading. Scanning electron microscopy micrograph of fracture surface under dynamic loading clearly displayed integrated bundle pull-out which implies suppressed in-bundle debonding and enhanced in-bundle interfacial strengthening, in contrast with extensive in-bundle debonding under quasi-static loading. Thus we conclude that, with 20 C/SiC composites, the strain rate sensitivity of in-bundle interface is mainly responsible for the strain rate sensitivity of the tensile strength. (C) 2011 Elsevier B.V. All rights reserved.