Scanning type laser ultrasonic detection method and system

Abstract

The invention discloses a scanning type laser ultrasonic detection method and system. The scanning type laser ultrasonic detection method comprises the following steps: controlling a laser to generate pulse laser beams by using host computer software; performing two-dimensional scanning on a tested material in the horizontal X-Y axis direction by using a galvanometer scanning device; receiving generated longitudinal wave signals by using a longitudinal wave sensor centered at a testing block; amplifying the received longitudinal wave signals, acquiring the generated longitudinal wave signals by using a digital A / D acquisition card, and performing band-pass filtering on acquired ultrasonic signals by using the host computer software; and controlling a scanning moving mirror system to perform two-dimensional scanning imaging on the surface of the material by using a computer control circuit system, and rapidly performing opto-acoustic imaging on the longitudinal wave signals received in the two-dimensional scanning process according to the fact that primary longitudinal wave peak value signals indicating whether the surface of the material has crack defects or not reach the sensor at different moments, thereby achieving rapid quantitative imaging detection on the defects of the detected material. The scanning type laser ultrasonic detection method is small in computer processing data amount, and the material defects can be directly quantitatively detected in a longitudinal wave transmitted image.

Description

technical field [0001] The invention belongs to the technical field of laser ultrasonic nondestructive testing, and relates to a scanning laser ultrasonic testing method; the invention also relates to a scanning laser ultrasonic testing system for material testing by implementing the scanning laser ultrasonic testing method. Background technique [0002] In industrial production, during the rolling process of metal sheets, it is easy to generate damage on the surface or inside of the sheet, and contact surface defects (such as surface defects, delamination, inclusions, etc.) are relatively common defects, and laser ultrasonic technology is suitable for detecting such defects. For contact surface damage, the signal-to-noise ratio and sensitivity of such defects can be significantly improved during the detection process, which has very important practical application value. Laser ultrasonic testing technology mainly uses laser to excite ultrasonic signals (including surface wa...

AI Technical Summary

Problems solved by technology

However, this kind of inspection system: the amount of inspection data processing is large, and the quantitative inspection of the shape and size of inspection defects cannot be realized.

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