论文部分内容阅读
利用扫描电镜(SEM)对编织炭/炭复合材料和混杂炭/炭复合材料的常温剪切试样进行了微观结构和断口形貌观察,探讨了裂纹形成和扩展方式,揭示了材料在加载过程中微结构不断演化导致材料最终破坏的断裂机理。分析结果表明,材料中微观缺陷,特别是界面缺陷的存在降低了材料力学性能,并可能成为材料失效的裂纹源;起始裂纹在剪切载荷作用下沿着结合力较弱的界面扩展,在遇到炭纤维束时,根据不同情况会以绕过、切过炭纤维束两种方式向前扩展,在这一过程中多种缺陷的存在将加速裂纹扩张速度并增加裂纹扩展范围,导致材料有可能在低应力状态下提早破坏。
The microstructure and fracture morphology of braided carbon / carbon composites and hybrid carbon / carbon composites at room temperature were observed by scanning electron microscopy (SEM). The formation and propagation of cracks were discussed. The effects of loading process Meso-micro-structure of the continuous evolution of materials led to the ultimate failure mechanism of fracture. The results show that the existence of microscopic defects, especially interface defects, can reduce the mechanical properties of the material and may become the source of the material failure. The initial crack propagates along the weaker bonding interface under the shear loading. Encountered carbon fiber bundles, depending on the situation will be bypassed, cut through the carbon fiber bundles in two ways to expand forward, in the process of a variety of defects will accelerate the crack growth rate and increase the crack propagation range, resulting in the material It is possible to prematurely destroy under low stress conditions.