Progress of Air-coupled Ultrasonic Non-destructive Testing Technology

Air-coupled ultrasonic non-destructive testing,possessing the characters of complete non-contact and non-destruction,can be used in some situations in which traditional ultrasonic testing is hardly applicable.The development of air-coupled ultrasonic non-destructive testing is summarized,and the main technical difficulties that restrict its progress are analyzed.Two methods to improve the efficiency of air-coupled ultrasonic transducers and corresponding research works are presented.Main detecting methods and corresponding application fields of air-coupled ultrasonic testing are introduced.It is concluded that air-coupled ultrasonic testing technique will be applied more widely in the future,however,the high efficiency transducer is a prerequisite for the successful application of the technology,and is also a focus of present research in this technical field.