Overview of Research Advances in Electromagnetic Acoustic Transducer

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.