Research On Electromagnetic Ultrasonic Mobile Scanning Device

Electromagnetic acoustic transducer(EMAT) have been widely studied over the last four decades, mainly connected to their noncontact nature. First, no couplant is needed. Furthermore, the inspection of high-temperature components and moving objects can be performed, EMAT can produce several kinds of ultrasonic wave-modes. Therefore EMAT technology extends the traditional ultrasonic nondestructive testing to the high temperature, high speed, online and other fields. This paper designs the electromagnetic ultrasonic mobile scanning device and its control system, which is based on the electromagnetic ultrasonic defect detection principle.In order to solve the problems and disadvantages existing in the detection of piezoelectric ultrasonic technology of aluminum alloy sheet, the electromagnetic ultrasonic scanning device is designed, which is based on electromagnetic ultrasonic defect detection method and combined with the domestic and foreign scanning device mechanism, the probe can scan separately in x, y direction, and also realize compound scanning, the height of the probe can be adjusted to detect the influence of lifting distance change in defect detection. The stepper motor control system based on single chip microcomputer realizes speed control and position control of the probe. The scan mode of the probe is set through the keyboard input(uniform scan mode、positioning mode). The scanning speed, scanning direction, moving straight distance of the probe could be adjusted, the scanning device can track scanning rapidly and accurately on aluminum alloy workpiece.