脉冲涡流缺陷检测理论与技术研究综述

Review of research on theory and technology of pulsed eddy current testing for detection of defects

由于具有非接触、效率高、检测信号的信息含量丰富等诸多优点,脉冲涡流技术被广泛应用工业产品的缺陷检测,尤其是带包覆层、异质、以及多层导电结构等检测难度极大的工业产品。脉冲涡流探头结构的设计和优化是提高检测灵敏度和准确度的关键,目前大量的研究工作围绕探头结构的设计和优化开展;不同材质、结构、以及缺陷类型或形状需要选用合适特征量表征,特征量的选取与分析也是脉冲涡流技术研究的关键;另外,由于脉冲涡流检测信号受提离高度影响极大,未知提离高度的缺陷准确检测面临极大的挑战,因此提离效应的抑制也是研究的重点之一。本文从探头的设计与开发、特征量的选取与分析、提离效应的抑制等方面,对脉冲涡流检测技术的研究进展进行综述。同时,为更好的推动脉冲涡流检测技术发展,论文在现有的研究基础上,对脉冲涡流探头设计、特征量分析、以及提离效应抑制等进行了展望。

Due to the advantages of non-contact,high efficiency,and rich information content of the detection signal,pulsed eddy current technology is widely used in the defect detection of industrial products,especially those with cladding,heterogeneous,and multi�layer conductive structures that are extremely difficult to detect.The design and optimization of pulsed eddy current probe structure is the key to improve the detection sensitivity and accuracy,and a lot of research work has been carried out around the design and optimization of the probe structure;different materials,structures,and defects of different types or shapes need to be characterized by the use of appropriate features,and the selection and analysis of the features is also the key to the research of pulsed eddy current technology;In addition,since the pulse eddy current detection signal is greatly affected by the lift-off height,the accurate detection of defects with unknown lift-off height faces great challenges,so the suppression of the lift-off effect is also one of the research focuses.In this paper,the research progress of pulsed eddy current detection technology is reviewed from the aspects of probe design and development,selection and analysis of feature quantity,and suppression of lift-off effect,etc.At the same time,in order to better promote the development of pulsed eddy current detection technology,the paper,on the basis of the existing research,makes an outlook on the design of pulsed eddy current probe,feature quantity analysis,and the suppression of lift-off effect.