铝合金激光超声表面检测中EMAT接收性能对比  

Comparation of reception performance of EMATs in laser ultrasonic surface detection of aluminum alloys

作　　者：何盼 卢超[1] 石文泽[1] 朱颖[1,2] 陈果 赵莉萍[1] HE Pan;LU Chao;SHI Wenze;ZHU Ying;CHEN Guo;ZHAO Liping(Key Laboratory of Nondestructive Testing,Ministry of Education,Nanchang Hangkong University,Nanchang 330063,China;State Key Laboratory of Acoustic Field and Acoustic Information,Academy of Acoustics,Chinese Academy of Sciences,Beijing 100190,China)

机构地区：[1]南昌航空大学无损检测教育部重点实验室,南昌330063 [2]中国科学院声学研究所声场声信息国家重点实验室,北京100190

出　　处：《航空学报》2023年第16期289-308,共20页Acta Aeronautica et Astronautica Sinica

基　　金：国家自然科学基金(12064001,52065049);江西省主要学科与技术带头人培养计划(20204BCJL22039,20225BCJ23023);江西省杰出青年基金(20212ACB214010);江西省重点研发计划(20212BBE51006,20223BBE51034);南昌航空大学研究生创新专项资金(YC2021-S694)。

摘　　要：在铝合金板材激光电磁超声换能器(Laser-EMAT)瑞利波(RW)检测中,曲折线圈EMAT、线性线圈面内EMAT和线性线圈面外EMAT常被应用于接收超声波,但是这3类EMAT的接收性能和应用场合尚不明确。为此首先建立铝合金Laser-EMAT RW检测过程的有限元模型,分析了3类EMAT配置形式对接收RW、横波和纵波等模式超声波能量的影响;其次研究了表面约束机制对RW幅值及其纯度的影响,探讨了3类EMAT的表面缺陷检测能力;最后制作了3类EMAT探头进行铝合金板材Laser-EMAT的RW检测实验,分析了表面约束机制对3类EMAT接收的各模式超声波幅值和表面缺陷检测能力的影响。结果表明:与线性线圈面内EMAT相比,曲折线圈EMAT和线性线圈面外EMAT接收的RW纯度更高,更适合表面缺陷检测;线性线圈面内EMAT接收到的多模式超声波明显,更适合同时检测表面/内部缺陷;与无表面约束机制相比,采用表面约束机制可将3类EMAT接收到的RW幅值增强2倍以上,其中对曲折线圈EMAT的RW幅值的增强作用最明显,且与无表面约束机制的激光-线性线圈面内EMAT相比,含表面约束机制的激光-线性线圈面外EMAT可将接收的DW幅值提高6倍以上。Meander-line coil Electromagnetic Acoustic Transducer(EMAT),linear coil in-plane EMAT,and linear coil out-of-plane EMAT are often used to receive ultrasonic waves in the laser-EMAT Rayleigh Wave(RW)detection of aluminum alloy plate.However,the reception performance and applications of these three types of EMATs remain un⁃clear.Therefore,a finite element model of the laser-EMAT RW detection process for aluminum alloys was first estab⁃lished,and the effects of three types of EMAT configurations on the energy of RW,shear wave,and longitudinal wave modes of ultrasonic were analyzed.Secondly,the effects of the surface constraint mechanism on the RW amplitude and its purity were studied,and the surface defect detection capability of the three types of EMATs was explored.Fi⁃nally,three types of EMAT probes were made,and RW detection experiments were carried out with laser-EMAT on aluminum alloy plates.The influence of the surface constraint mechanism on the amplitude of each mode of ultrasonic waves received by the three types of EMATs and the ability of surface defect detection was analyzed.The results show that compared to the linear coil in-plane EMAT,the meander-line coil EMAT and linear coil out-of-plane EMAT receive a higher purity RW and are more suitable for surface defect detection.The multi-mode ultrasonic wave re⁃ceived by the linear coil in-plane EMAT is obvious,which is shown to be more suitable for simultaneous detection of surface/internal defects.Compared to the non-surface constraint mechanism,the RW amplitude of three kinds of EMATs can be enhanced more than two times by using the surface constraint mechanism,with the enhancement of the RW amplitude of the meander-line coil EMAT being the most significant.Compared to the laser-linear coil in-plane EMAT without a surface constraint mechanism,the laser-linear coil out-of-plane EMAT with a surface constraint mechanism can increase the received DW amplitude by more than 6 times.

关 键 词：铝合金 Laser-EMAT 表面缺陷 表面约束机制 空间分辨率 

分 类 号：V261.3[航空宇航科学与技术—航空宇航制造工程] TB552[理学—物理]