激光超声结合电磁超声在铝板无损检测中的应用研究  

Application of Nondestructive Detection of Aluminum Using Laser Ultrasonic Technology and EMAT Method

作　　者：谷艳红 张振振 高先和[1] 石朝毅[1] 卢军[1] 张胜 周泽华[1] Gu Yanhong;Zhang Zhenzhen;Gao Xianhe;Shi Chaoyi;Lu Jun;Zhang Sheng;Zhou Zehua(Institute of Advanced Manufacturing Engineering,Hefei University,Hefei,Anhui 230601,China;Laser Insitute,Qilu University of Technology(Shandong Academy of Sciences),Jinan,Shandong 250103,China)

机构地区：[1]合肥学院先进制造工程学院,安徽合肥230601 [2]齐鲁工业大学(山东省科学院),山东省科学院激光研究所,山东济南250103

出　　处：《中国激光》2020年第5期413-419,共7页Chinese Journal of Lasers

基　　金：安徽高校省级自然科学研究项目重点项目(KJ2018A0547);合肥学院人才科研基金项目(18-19RC47)。

摘　　要：为了检测金属材料生产、使用过程中的厚度损失及表面裂缝损伤,对比分析了激光干涉仪和电磁超声换能器(EMAT)对金属激光超声信号探测的准确度和实用性。采用激光干涉仪表面波信号与纵波信号相结合的方法探测了铝板厚度,并根据背面纵波信号测量了铝板表面裂痕缺陷深度;采用EMAT表面波信号确定铝板裂痕缺陷的位置,纵波信号确定铝板的厚度。结果表明,相比激光干涉仪的复杂激光超声信号接收光路,EMAT铝板测厚及裂痕缺陷位置检测的误差均在4%以下,且裂痕缺陷位置的预测值不会随着表面裂痕缺陷深度的减小而增加。可见,采用激光超声与电磁超声相结合的方法可有效地降低检测条件的复杂性,提高激光超声的实用性。In this study,we compare the accuracy and applicability of laser interferometer and electromagnetic acoustic transducer(EMAT)with respect to the detection of the metal laser ultrasonic signals to detect the thickness loss and surface-breaking cracks with respect to the metals during the production and usage processes.The surface and longitudinal wave signals were detected using the laser interferometer for predicting the thickness of the aluminum plate,and the longitudinal wave signal on the back of the aluminum plate was detected using the laser interferometer to detect the depth of the defect.Surface wave signal of EMAT is used to determine the position of crack defect of aluminum plate,and longitudinal wave signal of EMAT is used to determine the thickness of aluminum plate.The results show that,compared with the laser interferometer′s complex laser ultrasonic signal receiving optical path,the errors of EMAT aluminum plate thickness measurement and crack defect location detection are less than 4%.And the prediction of the crack location will not increase with the decrease of the surface crack depth.Furthermore,the obtained results prove that the combination of the laser ultrasonic technology and the EMAT method can effectively reduce the complexity associated with the detection conditions and improve the applicability of laser ultrasonic technology.

关 键 词：测量 激光超声 电磁超声 无损检测 测厚 缺陷 

分 类 号：O426.9[理学—声学]