Flexible eddy current sensor for curved surface part defect detection

Abstract

The invention belongs to an electromagnetic and eddy current testing technology category in the field of nondestructive testing. When a traditional eddy current sensor is used for detecting a curved surface part, very loud lift-off noise exists in a detection signal since the lift-off height is continuously changed, so as to result in a very high missed detection probability, while a flexible eddy current sensor can well reduce the changes of the lift-off height to inhibit the lift-off noise due to the flexible and deformable characteristics thereof. According to the flexible eddy current sensor, a Koch fractal planar eddy current sensor is integrated into a flexible printed circuit board, and is bonded with flexible magnetic adhesive, so as to form a flexible array eddy current sensor. When detecting a ferromagnetic part, through the effect of magnetic force between the magnetic adhesive and the part, the sensor is attached to a test piece in a self-adapting manner, so that the lift-off noise caused by lift-off is avoided, thereby improving the sensibility of eddy current to curved surface detection.

Description

technical field [0001] The invention belongs to the technical field of electromagnetic eddy current nondestructive testing, and relates to a novel array eddy current sensor structure designed and manufactured for rapidly detecting tiny defects of curved ferromagnetic metal components. It can be used in the eddy current detection technology of components made of curved conductive materials, and provides a new detection scheme for the rapid detection of actual irregular components. Background technique [0002] Defects such as cracks and pores in metal materials affect the safety and reliability of mechanical products in service to a certain extent. Regular non-destructive testing of key components of mechanical products is an essential testing link, as well as machinery manufacturing and maintenance. and maintenance an important task. The eddy current sensor working on the principle of electromagnetic induction is an important detection method in conventional detection, whic...

AI Technical Summary

Problems solved by technology

[0003] The invention proposes a new type of flexible eddy current array sensor structure that can be automatically attached to the ferromagnetic test piece. This sensor utilizes the mutual attraction between the magnetic glue and the ferromagnetic component to integrate it into the flexible circuit board. The planar eddy current sensor can be automatically attached to the surface of the ferromagnetic metal material component, and the change of the lift-off height of each unit of the array sensor is very small during detection, which overcomes the traditional eddy current array structure in the detection of curved surface parts. Under the influence of the lift-off noise caused by the height change and the detection noise caused by the angle relationship between the sensor axis and the part surface, the detection efficiency is low and the missed detection rate is high, which effectively improves the reliability of the actual eddy current array. sex and speed

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