C/SiC复合材料的红外热像无损检测研究

摘要

采用红外脉冲热像检测方法对C/SiC复合材料试样中不同尺寸和深度的平底孔模拟缺陷进行无损检测,分析了红外脉冲热像检测方法的检测原理、红外脉冲热像检测结果和微分处理后的检测结果.研究结果表明,对于同一缺陷,红外脉冲热像图中显示的缺陷尺寸随时间变化规律近似服从卡方分布,并且在红外热波信号传播至缺陷深度时,显示的缺陷尺寸最大;对红外脉冲热像图进行微分处理,可提高小缺陷和深度缺陷的检测能力,且能够提高缺陷的识别度;红外脉冲热像法检测C/SiC材料,能发现最小直径为Φ2 mm的缺陷,无法发现深度大于4 mm(直径不大于Φ15 mm)的缺陷;该红外脉冲热像法检测C/SiC材料的最小径深比为1.3.%The flat bottom holes of different sizes and depths in C/SiC composite samples were nondestructively tested by using infrared pulse thermography testing method. The principle,processing and results of infrared pulse thermogra-phy testing were analyzed. The research results show that:for the same defect,the change of defect size with time ap-proximately obeys the chi－square distribution,and when infrared pulse spread to the depth of defect,the shown defect size is biggest;Testing and distinguishing ability for small and deep defects can be improved after differential process-ing;the method can test defects of 2 mm diameter,and can not test defects of deeper than 4 mm depth(not bigger than 1 5 mm diameter)in C/SiC composite;The minimal diameter/depth ratio of tested C/SiC composite is 1.3.