缺陷尺寸对红外热波技术缺陷深度测量的影响研究  

Effect of defect size on the measurement of defect depth using thermal wave imaging

作　　者：曾智[1,2] 陶宁[2] 冯立春[2] 张存林[2] 

机构地区：[1]重庆师范大学物理与电子工程学院,重庆400047 [2]首都师范大学物理系北京市太赫兹波谱与成像重点实验室太赫兹光电子学教育部重点实验室,北京100048

出　　处：《红外与激光工程》2012年第7期1910-1915,共6页Infrared and Laser Engineering

基　　金：国家自然科学基金(10804078;61079020);重庆市教委资助项目(KJ100605);重庆师范大学重点项目(06LB012)

摘　　要：缺陷深度测量是脉冲红外热波技术定量测量的一个重要应用,常用的几种测厚方法都是基于一维热传导模型。而实际测厚都是针对有限缺陷尺寸,因而三维热扩散会对深度测量产生一定影响。文中以表面阳极化处理后的铝和玻璃钢材料为例,采用脉冲红外热波技术作为实验方案。提取所获得的热图序列不同缺陷宽度位置处热波降温数据,利用这些数据近似模拟不同深度缺陷在相同缺陷尺寸时受到不同程度的三维热扩散影响。通过研究一维热传导理论模型分析了3种常用方法的测厚原理,并建立了测厚特征时间与缺陷深度平方线性关系。结果表明:缺陷尺寸对各线性关系的斜率和截距均有影响,且热扩散系数较小材料的斜率明显大于热扩散系数较大材料。Defect depth measurement is one of the major quantitative applications of thermal wave imaging and the current methods are based on 1D heat conduction model. However, since the practical depth measurement is to retrieve defect depth which is of limited size. 3D heat diffusion influences the precision of defect depth measurement. One aluminum sample whose surface was treated with anode oxidation and one fiber reinforced plastics （FRP） sample were used, and thermal wave imaging was used as experimental scheme to obtain the temperature decay data series. The temperature-time curves of different positions in each wedge were extracted to approximately simulate that different depth defects with the same defect size were affected with different levels of 3D heat diffusion. The theoretical procedures of three different thickness measurement methods were analyzed based on 1D heat conduction model, and the linear relationship between the characteristic time of each method and the square of defectdepth was constructed. The results indicate that defect size influences the slope and intercept of each linearity, and the slope is affected more seriously when the thermal diffusivity is smaller.

关 键 词：红外热波技术 缺陷深度 测厚 三维热扩散 

分 类 号：O434.3[机械工程—光学工程]