Phased array ultrasonic detection method for butt-weld joint of aluminum alloy sheet

Abstract

The invention discloses a phased array ultrasonic detection method for a weld joint of an aluminum alloy sheet. The phased array ultrasonic detection method comprises the following steps of: a, pretreating a detected surface; b, designing a tile-shaped focusing probe according to the weld joint detection requirement of an aluminum alloy sheet, and enabling electrons in phased array ultrasonic detection to generate a focusing effect; c, preparing portable equipment for phased array ultrasonic detection, a detection wedge block and a calibration test block; d, calibrating the accuracy of the detection wedge block, calibrating the sound velocity and the sensitivity, and calibrating an encoder; and e, performing detection on site, and then analyzing and judging according to phased array detection data and images to finish detection. During use, phased array ultrasonic beams can be physically focused in the transverse direction, acoustic beams can be better focused in a weld joint, the acoustic energy of a focusing area is improved, the influence of factors such as acoustic energy attenuation and acoustic scattering on the signal-to-noise ratio can be reduced, the detection effect of air holes in the weld joint of an aluminum alloy sheet is improved, the blind area of weld joint detection is reduced, the primary wave coverage area is increased, and the detection reliability is improved.

Description

technical field [0001] The invention relates to the technical field of material detection, in particular to a phased array ultrasonic detection method for welding seams of aluminum alloy thin plates. Background technique [0002] Aluminum alloy materials are widely used in the superstructure and part of the hull of ships, and their thickness is relatively thin, generally less than 10mm. As the main joining process, welding is widely used in the butt joint and fillet joint process of aluminum alloys. In the process of ship construction, a large number of welds will be formed. [0003] One of the commonly used ultrasonic testing methods in the aviation industry is water-filled phased array ultrasonic testing. This method grinds the weld reinforcement to be flush with the base metal, reducing the influence of the probe front. It is reported that it is applied to friction stir Inspection of welded seams. Water-filled phased array ultrasonic testing can be realized in workshops...

AI Technical Summary

Problems solved by technology

[0006] Ultrasonic testing technology, as an internal quality testing technology for welds with little environmental impact, can overcome the problems of radiographic testing in on-site testing. However, when conventional ultrasonic testing of aluminum alloy sheet welds, due to the influence of near-field length and scattering, it is easy to cause missed inspections. In addition, the detection effect of a single angle of conventional ultrasonic testing on the area defects in aluminum alloy welds is easily missed due to the influence of the angle, and the uncertainty of the sound pressure reflection amplitude in the near field and the thin plate structure will cause the conventional ultrasonic reflection signal to be noisy. There are more waves, the possibility of misjudgment is greatly increased

[0007] At present, there are no public reports and perfect solutions at home and abroad, which can completely solve the technical difficulties of ultrasonic testing of thin-plate aluminum alloy welds and form a reliable detection method. Therefore, a feasible phase control of aluminum alloy thin plates to welds is urgently needed Array Ultrasonic Testing Method

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