激光-环型电磁超声方法检测表面裂纹  

The Method of Surface Cracks Testing with Laser/Ring-EMAT

作　　者：弋东驰 裴翠祥(指导)[1] 陈振茂[1] 

机构地区：[1]机械结构强度与振动国家重点实验室,陕西省无损检测与结构完整性评价工程技术中心,西安交通大学,西安710049

出　　处：《无损检测》2016年第11期70-73,共4页Nondestructive Testing

摘　　要：传统激光-电磁超声对表面裂纹检测的灵敏度受表面裂纹方向的影响,为解决这一问题,提出了一种基于环形电磁超声探头的激光-电磁超声无损检测方法。相比于传统的激光-电磁超声表面裂纹检测方法,该方法不但具有更高的灵敏度,而且不受裂纹方向的影响。为了验证该方法的有效性,设计了一种环形电磁超声探头,并对其线圈参数进行了优化,提高了检出信号的信噪比;进而利用该环形探头有效检出了试件中的不同方向表面裂纹。With using pulsed laser to excite electromagnetic acoustic transducers（EMATs）and generate ultrasonic waves,laser-EMAT can provide a noncontact ultrasonic testing（UT）method.To overcome the drawback that sensitivity of traditional laser-EMAT UT method is dependent on the direction of defect to be measured,a modified laser-EMAT UT method with using a ring EMAT is proposed in this work.Compared to the traditional laser-EMAT method,the sensitivity of the laser-ring EMATUT is much higher,and independent to the crack orientation.To validate the feasibility of this method,a ring EMAT is firstly designed and optimized to improve the sensitivity for laser ultrasound detection.Then,the laser-ring EMAT system is applied to scan a specimen with a normal surface crack.

关 键 词：激光超声 电磁超声 无损检测 表面裂纹 

分 类 号：TG115.28[金属学及工艺—物理冶金]