Annular laser-electromagnetic ultrasonic focusing probe

Abstract

The invention provides an annular laser-electromagnetic ultrasonic focusing probe which comprises a probe shell, an optical lens group, an optical fiber, an annular permanent magnet, an annular receiving coil and an annular focusing laser beam. The optical lens group is fixed in the probe shell, the optical fiber is connected at the top of the probe shell and used for leading in a single-beam laser source, the annular permanent magnet is fixed at the bottom of the probe shell, the annular receiving coil is centrally pasted at the bottom of the annular permanent magnet, the single-beam laser source led-in by the optical fiber is coincided with an optical axis of the optical lens group, the annular focusing laser beam is formed at a probe outlet and used for exciting focusing ultrasonic waves in a metal sample, and the inner diameter of the annular permanent magnet and the annular receiving coil is larger than the outer diameter of the annular focusing laser beam. According to the focusing probe, the optical lens group generates annular lasers, ultrasonic body waves of point focusing can be excited, focusing ultrasonic echo signals are received by the aid of the annular permanent magnet and the annular receiving coil, integral transceiving is achieved, and the capability for detecting defects of metal structure bodies is enhanced. The probe is compact in structure, convenient to move and operate and high in detection efficiency and can be used for detecting inner defects of metal materials.

Description

technical field [0001] The invention relates to a non-contact ultrasonic detection technology, in particular to a ring laser-electromagnetic ultrasonic focusing probe, which can be used for detection and evaluation of internal defects of metal materials. Background technique [0002] The laser-electromagnetic ultrasonic testing method is a composite non-contact ultrasonic testing technology that uses pulsed lasers to excite ultrasonic waves and uses electromagnetic ultrasonic probes to receive ultrasonic signals. This method combines the advantages of high laser ultrasonic excitation efficiency, wide frequency band, high electromagnetic ultrasonic detection sensitivity, and little influence on the surface state of the test piece, and has great application potential. However, due to the strong surface waves generated in metal materials under the laser ultrasonic thermoelastic mode, the body waves are weak and the beam energy distribution is not concentrated. Therefore, laser...

AI Technical Summary

Problems solved by technology

However, due to the strong surface waves generated in metal materials in the laser ultrasonic thermoelastic mode, the body waves are weak and the beam energy distribution is not concentrated

Therefore, laser-electromagnetic ultrasound is currently mainly used for the detection of surface defects, and it is more difficult to detect internal defects.

In addition, the current laser-electromagnetic ultrasonic testing technology at home and abroad adopts the one-shot-one-retract split-body detection mode, that is, the laser and electromagnetic ultrasonic probes are located at different positions of the specimen, resulting in an uncompact design of the entire probe device and inconvenient operation.

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