炭/炭复合材料的微观结构及剪切断裂机理研究  

An investigation on microstructure and failure mechanism of carbon-carbon composites on shear test

作　　者：马李[1] 何录菊[2] 王古平[3] 史勤益[3] 周苗荣[3] 

机构地区：[1]广东石油化工学院机电工程学院,广东茂名525000 [2]广东石油化工学院教育信息技术中心,广东茂名525000 [3]台州学院物理与电子工程学院,浙江台州318000

出　　处：《炭素技术》2015年第2期10-14,共5页Carbon Techniques

基　　金：浙江省新苗人才计划(2013R428011);浙江省科技厅公益性技术应用研究计划项目(2014C37085)

摘　　要：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。Microstructure and fracture appearance of braided carbon-carbon （C/C） composites specimen and hybrid carbon-carbon composites specimen during shear test under normal temperature has been studied by means of SEM. Then modes of crack tormation and propagation are analyzed and fracture mechanism of the composite that the evolution of microstrueture under loading leads to failure is disclosed. The results show that the microdefect especially the interface defect in materials will impair the mechanical property and is likely to become the crack source which will lead to failure; the initiative crack will spread along the interface with low binding force under shear load and take two modes to outspread-round or traverse carbon fibre according to different situations. During the course all kinds of defects will accelerate the speed and increase the scope of crack extension so that making it possible for materials to be disabled in advanced under low stress.

关 键 词：炭/炭复合材料 剪切 微观结构 断口分析 界面 

分 类 号：TB332[一般工业技术—材料科学与工程]