主动红外热像无损检测技术的研究现状与进展

摘要

与渗透、磁粉、射线等传统无损检测技术相比,主动红外热像技术具有非接触、无污染、高效率等优点,已成为一种重要的材料表面和近表面缺陷无损检测技术,该技术包括主动热激励、表面热图采集和图像处理3个步骤.对热灯、超声波、电磁线圈、微波、激光等几种主要热激励手段进行了对比分析,分别总结了其特点、适用范围及研究应用现状;热图采集效果主要取决于红外热像仪的性能高低;图像处理依靠各种图像处理软件进行,当前应用于红外热像检测中的图像处理方法有背景减去、噪声去除、时间平均等.随着热激励技术和图像处理技术的发展,以及红外热像仪性能的提高,主动红外热像无损检测技术也呈现出由人工识别向自动识别、由定性检测向定量检测、由单一手段向复合手段发展的趋势.%Kinds of nondestructive testing (NDT)technique are important methods for material quality control and performance evaluation.Compared with traditional NDT methods such as osmosis testing,magnetic particle testing,and ray testing,active infrared thermography has become a significant NDT technique in surface and sub-surface defects detection for the advantages of non-contact,non-pollution and high efficiency.This technique consists of three main steps,active thermal excitation,surface thermal image collecting and thermal image processing.As thermal exciting agents,thermolamp,ultrasonic wave,magnetic coil,microwave and laser are comparatively analysed,their characteristic,sphere of application and research states are summarized.The effect of thermal image collecting is rest on the performance of thermal infrared imager.Thermal image processing relies on professional software.Background subtract,noise elimination and time average are frequently-used methods in active infrared thermography at present.At last,it is pointed out that as a result of advances in thermal excitation,image processing and thermal infrared imager,some tendencies have appeared in active infrared thermography,such as from artificial cognition to machine cognition,from qualitative detection to quantitative detection and from single technique to complex technique.