论文部分内容阅读
采用先驱体浸渍裂解法制备三维编织的C/SiC复合材料,利用自主研发的高温散斑制作技术和改进的三维变形光学测试系统,基于数字图像相关技术测试原理,在高温小尺度下实时表征分析C/SiC复合材料的力学性能。运用X射线衍射和扫描电子显微镜测试分析了材料高温氧化情况、显微组织结构及裂纹扩展情况。研究表明:温度对C/SiC复合材料的性能有很大的影响。随着温度的升高,材料由脆性断裂逐渐转变为韧性断裂;材料的断裂韧性由7.98±0.12MPa·m~(1/2)减小到2.76±0.11MPa·m~(1/2),断裂强度从251.40±2.71MPa减小到86.94±1.82MPa。本文为掌握C/SiC复合材料的高温失效机理提供了一种有效的实验测试技术和方法。
The three-dimensional braided C / SiC composites were prepared by the precursor impregnation and pyrolysis method. Based on the self-developed high-temperature speckle fabrication technology and the improved three-dimensional deformation optical test system, based on the digital image correlation test principle, real-time characterization analysis Mechanical Properties of C / SiC Composites. The conditions of high temperature oxidation, microstructure and crack propagation were analyzed by X-ray diffraction and scanning electron microscopy. The results show that temperature has a great influence on the properties of C / SiC composites. With the increase of temperature, the material changed from brittle fracture to ductile fracture gradually. The fracture toughness decreased from 7.98 ± 0.12MPa · m ~ (1/2) to 2.76 ± 0.11MPa · m ~ (1/2) The breaking strength decreased from 251.40 ± 2.71MPa to 86.94 ± 1.82MPa. This article provides an effective experimental test technique and method for grasping the mechanism of high temperature failure of C / SiC composites.