A device for measuring the thickness of a coating by magnetoresistive concentration of magnetic flux

Abstract

This invention belongs to the field of detection technology and discloses a magnetoresistive magnetic field measurement device for coating thickness, including magnetic core I (1), coil I (2), magnetic core II (3), and coil II (4). Both magnetic core I and magnetic core II have a "gate" shaped frame structure, arranged at 90° and in a cross-shaped configuration. The bottom of the "gate" shaped frame is vertically positioned on the coating surface. Coil I (2) is wound around the top beam of magnetic core I (1), and coil II (4) is wound around the top beam of magnetic core II (3). Alternating current flows through coil I (2) and coil II (4). This invention utilizes the principle of magnetic field concentration to penetrate thicker coatings, achieving non-destructive measurement, providing accurate coating measurement results, and improving measurement efficiency and sensitivity.

Description

Technical Field

[0001] This utility model belongs to the field of detection technology, and in particular relates to a magnetoresistive magnetic field measuring device for coating thickness. Background Technology

[0002] In recent years, coating thickness measurement has been widely applied in industries such as weaponry, aviation, aerospace, and shipbuilding, primarily involving product quality control, material protection, and the promotion of technological innovation. As an important surface protection measure, the uniformity and density of coating thickness significantly impact its protective effect and service life. Therefore, coating thickness testing is crucial for ensuring product quality and performance. In practical applications, coating thickness measurement methods include both non-contact and contact methods. Non-contact methods, such as laser thickness measurement and eddy current thickness measurement, are fast and non-destructive, but their accuracy is affected by factors such as ambient temperature and surface roughness. Contact methods, such as micrometer and caliper methods, are simple to operate and offer high measurement accuracy, but they can cause some damage to the coating surface.

[0003] Therefore, there is an urgent need to develop a completely new coating thickness measurement device to overcome the problems existing in the current technology. Utility Model Content

[0004] The technical problem to be solved by this invention is: how to accurately measure the coating thickness without damage.

[0005] To solve the above-mentioned technical problems, the specific technical solution of this utility model is as follows:

[0006] A magnetoresistive magnetic field measuring device for coating thickness includes a magnetic core I1, a coil I2, a magnetic core II3, and a coil II4;

[0007] Both magnetic core I and magnetic core II have a "gate" shaped frame structure. Magnetic core I and magnetic core II are arranged at 90° and cross-shaped. The bottom of their "gate" shaped frames is vertically set on the coating surface. Coil I2 is wound on the top beam of magnetic core I1, and coil II4 is wound on the top beam of magnetic core II3. Alternating current is passed through coil I2 and coil II4.

[0008] Low-frequency alternating current is passed through coil I2 and coil II4.

[0009] The bottoms of magnetic core I1 and magnetic core II3 are tightly attached to the surface of coating 5.

[0010] The magnetic core I1 and magnetic core II3 are more than 40 mm away from the edge of the substrate 6 with the coating.

[0011] The substrate 6 is a ferromagnetic material.

[0012] Among them, coil I2 and coil II4 are both inductors, which are wound with enameled wire with a diameter of 0.2mm on magnetic core I1 and magnetic core II3.

[0013] The number of turns of coil I2 and coil II4 is 1000.

[0014] This invention has the following advantages: it can penetrate thicker coatings by utilizing the principle of magnetic focusing, achieving non-destructive measurement, providing accurate measurement results for the coating, and improving measurement efficiency and sensitivity. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of a magnetoresistive magnetic field measuring device for measuring coating thickness according to this utility model.

[0016] In the diagram: 1. Magnetic core I; 2. Coil I; 3. Magnetic core II; 4. Coil II; 5. Coating; 6. Substrate. Detailed Implementation

[0017] To better understand the purpose, structure, and function of this utility model, a more detailed description of this utility model is provided below with reference to the accompanying drawings.

[0018] like Figure 1 As shown, this embodiment of a magnetoresistive magnetic field measurement method for coating thickness includes a magnetic core I1, a coil I2, a magnetic core II3, a coil II4, a coating 5, and a substrate 6. Specifically, its working process is as follows: First, coil I2 is wound around magnetic core I1, and coil II4 is wound around magnetic core II3. To avoid the lift-off effect, magnetic cores I1 and II3 are arranged in a cross shape and tightly attached to the surface of coating 5. Then, based on the principle of electromagnetic induction, low-frequency alternating current is applied to coils I2 and II4 respectively, generating magnetic flux 1 and magnetic flux 2. Magnetic flux 1 passes through magnetic core I1 and substrate 6 to form a closed loop 1. Similarly, magnetic flux 2 passes through magnetic core II3 and substrate 6 to form a closed loop 2. The intersection of circuit 1 and closed loop 2, i.e., the center of the cross intersection of magnetic flux 1 and magnetic flux 2 on the substrate 6, is guided by the cross structure constructed by magnetic core I1 and magnetic core II3 to superimpose the two strong magnetic fields at the cross intersection to enhance the magnetic focusing effect, which can penetrate the thicker coating 5. Finally, the magnetic reluctance signal in the magnetic circuit is collected. When the thickness of coating 5 is different, the magnetic reluctance in the magnetic circuit is different. For thinner coating 5, the magnetic reluctance in the circuit is smaller, and for thicker coating 5, the magnetic reluctance in the circuit is larger. Therefore, the thickness information of coating 5 can be obtained according to the magnetic reluctance.

[0019] Preferably, to reduce the skin effect of eddy currents, the current flowing through coil I and coil II is low-frequency alternating current with a frequency range of tens to hundreds of hertz.

[0020] Preferably, to avoid lift-off effect, the magnetic core I and magnetic core II are tightly bonded to the coating surface.

[0021] Preferably, to avoid edge effects, the magnetic core I and magnetic core II should not be too close to the edge of the substrate, and the distance between them should be greater than 40 mm.

[0022] Preferably, the matrix is ​​a ferromagnetic material with strong magnetic conductivity.

[0023] Preferably, the magnetic core I and magnetic core II are of a "Π" shaped structure (a "gate" shaped frame structure). The magnetic core I and magnetic core II are arranged at 90° and are arranged in a cross shape on the coating surface. The cross structure formed by the magnetic core I and magnetic core II guides the two strong magnetic fields to superimpose at the cross point to enhance the magnetic focusing effect.

[0024] Preferably, both coil I and coil II are inductors, which are wound with enameled wire of 0.2 mm in diameter on magnetic core I and magnetic core II, and the number of turns of coil I and coil II is 1000.

[0025] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and improvements without departing from the principles of the present invention, and these modifications and improvements should also be considered to fall within the protection scope of the present invention.

Claims

1. A device for measuring the thickness of a magnetic coating by means of a magnetoresistive effect, characterized in that It includes magnetic core I (1), coil I (2), magnetic core II (3), and coil II (4); Both magnetic core I and magnetic core II have a "gate" shaped frame structure. Magnetic core I and magnetic core II are arranged at 90° and cross-shaped. The bottom of the "gate" shaped frame is vertically set on the coating surface. Coil I (2) is wound on the top beam of magnetic core I (1), and coil II (4) is wound on the top beam of magnetic core II (3). Alternating current is passed through coil I (2) and coil II (4).

2. The magnetoresistive, flux concentrating, device for measuring coating thickness according to claim 1, wherein, Low-frequency alternating current is passed through coil I (2) and coil II (4).

3. The magnetoresistive, flux concentrating, device for measuring coating thickness of claim 1, wherein, The bottoms of magnetic core I (1) and magnetic core II (3) are tightly attached to the surface of coating (5).

4. The magnetoresistive, flux concentrating, device for measuring coating thickness of claim 1, wherein, The distance between the magnetic core I (1) and magnetic core II (3) and the edge of the coated substrate (6) is greater than 40 mm.

5. A device for magnetoresistive magnetoencephalography measurement of coating thickness according to claim 4, characterized in that, The substrate (6) is a ferromagnetic material.

6. The magnetoresistive, flux concentrating, device for measuring coating thickness of claim 1, wherein, Both coil I (2) and coil II (4) are inductors, which are wound with enameled wire of 0.2 mm in diameter on magnetic core I (1) and magnetic core II (3).

7. The magnetoresistive, flux concentrating, device for measuring coating thickness of claim 6, wherein, The number of turns of coil I (2) and coil II (4) is 1000.

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