Ultrasonic thickness measurement device and method for multilayered wave-absorbing coatings

Abstract

The invention relates to an ultrasonic thickness measurement device and method for multilayered wave-absorbing coatings, and belongs to the technical field of ultrasonic non-destructive testing and evaluation. The device comprises a portable digital ultrasonic flaw detector with a bandwidth ranging from 0 to 35 MHz, a delay block probe or an ultrasonic delay line probe partly immersed in water, a coating sound velocity calibrated sample and a computer integrated with a thickness measuring arithmetic. The device is characterized in that the coating thickness is calculated by selecting delta t or fn according to the characteristic of ultrasonic echo wave; and through the iteration windowing analysis by combining the autocorrelation method with the sound pressure reflection coefficient power spectrum method, the coating thickness measuring is realized by selecting an exact fn. The device and the method have the advantages that the limitations that in the conventional ultrasonic thickness measuring technology, the requirements to frequency bands of a flaw detector and the probe are high; the data interception needs manual intervention, and the device is only suitable for single-layer coating, are overcome; the size of the device is small; the weight is light; and the device is suitable for the on-the-spot thickness measuring of various matrixes and outer layers of multilayered coatings, and has major economic benefits and social benefits.

Description

Technical field [0001] The invention relates to a thickness measuring device and a thickness measuring method for detecting multilayer wave-absorbing coatings by ultrasonic, which belongs to the technical field of ultrasonic nondestructive inspection and evaluation. Background technique [0002] The use of absorbing materials for radar wave stealth is a very economical and effective technical approach, and the thickness of radar absorbing materials and the uniformity of the coating layer directly affect the final stealth effect. In the process of on-site coating construction and quality inspection, the thickness of each layer of absorbing coating is required to meet the qualified standard. Accurate and reliable nondestructive testing method for the thickness of the absorbing coating is an urgent engineering demand in this field. [0003] The current non-destructive testing methods for the thickness of the absorbing coating mainly include the magnetic method, the eddy current metho...

AI Technical Summary

Problems solved by technology

Compared with the existing thickness measurement method of absorbing coating, this method should overcome the limitation that the traditional ultrasonic thickness measurement method must be able to read the two resonant frequencies in the signal amplitude spectrum / power spectrum to obtain the coating thickness accurately. There is no requirement for the electrical and magnetic properties of the wave-absorbing coating, and it can accurately measure the thickness of the outermost layer of single-layer and multi-layer wave-absorbing coatings

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