Non-contact type measuring method and device for metal surface coating thickness

Abstract

Provided is a non-contact type measuring method and device for metal surface coating thickness, and a non-contact type eddy current detection probe is correspondingly selected according to the size ofa to-be-tested piece so as to carry out calibration, so that a relation curve of the eddy current signal and the corresponding lifting distance is obtained, and a metal matrix vortex ranging model ofthe to-be-tested piece is built, a vortex signal of the eddy current sensor is obtained in the detection process, and the distance from the center point of the metal matrix vortex area to the end surface of the eddy current probe according to the metal matrix vortex ranging model of the to-be-tested piece, and further the distance from the center point of the outer surface of the coating layer ofthe eddy current area to the plane, namely, the detection plane Pi where the light projection point of the laser ranging sensor group is located is measured according to the laser ranging sensor group, and finally the metal matrix surface coating thickness is obtained through calculation. According to the invention, stable and reliable nondestructive non-contact detection can be realized, and thedata processing method is simple, on-line detection is easy, so that a lot of economic cost and time are saved.

Description

technical field [0001] The invention relates to a technology in the field of mechanical processing, in particular to a non-contact method and device for measuring the coating thickness of a metal surface based on an eddy current sensor and a laser ranging sensor. Background technique [0002] In engineering applications, in order to increase the fire resistance and corrosion resistance of metal containers and pipes, non-metallic materials that are resistant to ablation and corrosion are usually pasted or sprayed on their inner or outer surfaces. The thickness of these covering layers plays an extremely important role in the characteristic analysis, quality control, working performance of the whole test piece, and its stability, reliability and service life. [0003] The existing non-destructive testing methods for coating thickness include magnetic thickness measurement, ultrasonic thickness measurement, laser thickness measurement and eddy current thickness measurement. Am...

AI Technical Summary

Problems solved by technology

Among these methods, eddy current thickness measurement is widely used for its advantages of no coupling agent, high sensitivity, simple structure, no influence of oily medium, fast detection speed and easy automation. It is commonly used in the measurement of coating thickness on the surface of flat metal substrates In the process of measurement, the probe is placed close to the surface of the coating, and the distance the probe is lifted is the thickness of the coating. This method is generally used for the measurement of dry coatings. It is basically a contact measurement, and sometimes it will cause damage to the coating surface. And for curved substrates, the resulting thickness value includes the curvature-induced datum offset

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