混杂碳/碳复合材料超高温拉伸断裂模式

Research on tensile fracture mechanism of hybrid CARBON-CARBON composites at ultra high temperature

通过电子扫描电镜 (SEM)研究了混杂碳 /碳复合材料的组分微结构形态、内部微缺陷产生的原因以及随温度升高的演化规律 ,结合超高温拉伸试件断口的形貌分析 ,揭示了超高温条件下混杂碳 /碳复合材料的断裂机理。在温度和载荷载的作用下 ,基体内的孔洞和微裂纹逐渐融合、扩展、长大 ,纤维 /基体界面结合减弱、脱开 ,形成大的裂纹并沿着纤维 /基体界面迅速扩展 ,使得材料的性能退化 。

The present paper is concerned with the evaluation of microstructure and interior defects of hybrid carbon-carbon composites with increasing temperature. The fracture mechanism of hybrid carbon-carbon composites is also investigated from SEM photographs of fractured surfaces of specimens experienced ultra-high temperature under tensile load, the conclusion is therefore obtained that the porous and cracks coalescence, growth and propagation and the fiber/matrix interfaces degeneration under the combination of ultra-high temperature and load cause strength descend, composite would fractured from a weak section.