电磁超声换能器的研究进展综述

Overview of Research Advances in Electromagnetic Acoustic Transducer

电磁超声换能器是一种新型的超声波发射接收装置。因为无需与被测物接触,EMAT将传统的超声无损检测技术扩展到了高温、高速和在线检测中;同时,由于能够省略对被测物表面较为繁琐的预处理工作,EMAT显著提高了检测效率。目前,在充分发挥电磁超声自身优势的基础上,通过与其他新技术相结合、并应用多种新的建模和信号处理方法,EMAT的功能已变得日益强大。以近十几年的文献为基础,从EMAT装置的设计与优化、EMAT模型的建立、EMAT接收信号的处理、电磁超声技术的工程应用几方面对EMAT的研究现状和最新发展进行了综述。

Electromagnetic acoustic transducer （EMAT） is a new ultrasonic transmitting and receiving device. As no complete contact is required between the transducer and the test piece, EMAT has extended traditional ultrasonic applications into elevated temperatures, high speeds and in-line detection fields. In addition, without the necessity of a good surface condition, the time consuming and complicated preparation works of the test piece also can be omitted,and thus lead to a great improvement of the detection efficiency. Nowadays,on the basis of its predominant advantages,the functions of EMAT have been profoundly improved by the combination with other new techniques and by the utilization of many new modeling and signal processing methods. Based on papers published in the past ten years, the present state of research and advancements in this field were summarized, including design and optimization of EMAT, modeling of EMAT, signal processing of EMAT, and applications of electromagnetic acoustic technique.