Experimental device for testing anisotropy of stress-induced magnetic Barkhausen noise

Abstract

The invention discloses an experimental device for testing anisotropy of stress-induced magnetic Barkhausen noise, and the device achieves the adjustment of an included angle among a magnetic field, stress and an initial easy-magnetization axis in a tested material through the cooperation of a working time sequence of a disc rotation module, an excitation field rotation module and a uniaxial stretching device. The magnetic Barkhausen noise signals of all direction angles in the rotation process of the excitation field are tested through the magnetic detection instrument module, magnetic characteristic parameters are extracted, the change rule of the magnetic characteristic parameters along with the direction angles is drawn, and then the test result of the anisotropy of the magnetic Barkhausen noise is obtained. According to the combined technical scheme of uniaxial stretching and excitation field rotation along the diameter line of the disc, the influence rule of factors such as stress and rolling direction on the anisotropy of the magnetic Barkhausen noise can be finely tested in a single test piece.

Description

Technical Field

[0001] The present invention belongs to the technical field of nondestructive testing, and further belongs to the technical field of magnetic Barkhausen noise testing. Specifically, it relates to an experimental device for testing the anisotropy of stress-induced magnetic Barkhausen noise. Background Art

[0002] In recent years, with the increasingly stringent requirements of the high-end equipment manufacturing industry for the service safety of materials, the nondestructive testing technology based on magnetic Barkhausen noise (MBN) has shown unique advantages in stress state evaluation and material property degradation monitoring due to its high sensitivity and non-contact characteristics. The MBN signal generally exhibits significant anisotropic characteristics, and its formation can be attributed to the synergistic effect of external excitation (including applied stress σ, external magnetic field H and their vector directions) and intrinsic properties (such as grain orientation, grain boundary distribution, etc.).

[0003] Current research mostly focuses on the MBN response under single-direction stress and magnetic field, such as "A.A. Samimi, T.W. Krause, L. Clapham. Multi-parameter Evaluation of Magnetic Barkhausen Noise in Carbon Steel [J]. Journal of Nondestructive Evaluation, 2016, 35(3): 1-8", "V. Moorthy. Important factors influencing the magnetic Barkhausen noise profile [J]. IEEE Transactions on Magnetics, 2016, 52(4): 1-13". However, the existing technology is difficult to finely test the influence law of factors such as stress and rolling direction on the anisotropy of magnetic Barkhausen noise in a single specimen, which restricts the application accuracy of the MBN technology in multi-axial stress detection in industry.

[0004] Therefore, in order to reveal the regulation law of factors such as stress and rolling direction on the anisotropy of MBN, an experimental device for testing the anisotropy of stress-induced magnetic Barkhausen noise is urgently needed to be developed. Summary of the Invention

[0005] The present invention provides an experimental device for testing the anisotropy of stress-induced magnetic Barkhausen noise, which is used to solve the technical problem that it is difficult to finely test the influence law of factors such as stress and rolling direction on the anisotropy of magnetic Barkhausen noise in a single specimen.

[0006] In order to achieve the above purpose, the technical solution provided by the present invention is:

[0007] Integrate a disk rotation module, an excitation magnetic field rotation module, and a uniaxial stretching device to form a multi-angle force-magnetic field loading platform. The excitation magnetic field rotation module includes a U-shaped electromagnet, an electromagnet fixture, a coupling, an electric rotary table driven by a servo motor, and a Z-axis manual displacement table, where: (1) The excitation method uses a U-shaped electromagnet, which is fixed by an electromagnet limit block and a fixture; (2) The rotation drive method consists of an electric rotary table that realizes torque transmission through a coupling. The rotation step angle is controlled by the host computer, and the positioning accuracy is ±0.1°; (3) The lift-off distance adjustment is precisely controlled by a Z-axis manual displacement table. The disk sample rotation module includes a barrel-shaped load platform with a V-groove positioning structure, a limit block, a manual rotary table with a scale accuracy of 2°, and a rotary table base. When implementing stress loading, the stress direction is loaded within the range of 0-90° by rotating the sample step by step.

[0008] Based on a three-axis electric positioning system, integrate a multi-angle force-magnetic field loading platform and an MBN detection instrument. The MBN sensor is connected to a breadboard on the Z-axis electric slide table through a tripod, and the host computer controls to achieve constant-pressure contact between the sensor probe and the sample surface; the multi-angle force-magnetic coupling loading platform is configured on the breadboard of the X / Y-axis electric slide table, and the host computer precisely positions the area to be measured of the sample to the projection area of the detection probe by controlling the X / Y-axis linkage.

[0009] The steps for detecting the anisotropy of magnetic Barkhausen noise under stress loading are as follows:

[0010] (1) Sample clamping and system calibration stage: Place the disk sample in the V-groove fixture of the barrel-shaped load platform, apply a pre-tightening force using the limit block to restrict the degrees of freedom of the sample; use the three-axis positioning system to calibrate the horizontal position and lift-off distance of the probe, and use the Z-axis displacement table of the rotary excitation device to adjust the lift-off distance of the electromagnet.

[0011] (2) Force-magnetic parameter setting stage: Set the stress loading scheme σ i (i = 1, 2,..., N) of the stretching device, and set parameters such as the rotation step Δβ, excitation frequency, and amplitude of the rotary excitation device.

[0012] (3) Automatic detection stage: Apply a pre-tensile load σ i and hold it. The rotary excitation device deflects the magnetic field direction at the set step Δβ, synchronously triggers the output of the excitation current of the electromagnet and the acquisition of the magnetic Barkhausen noise signal of the sensor, and the host computer processes the signal in real time and extracts the magnetic characteristic parameter M n (n = 1, 2,..., S).

[0013] (4) Repeat step (3) until the tests under all set loading stresses σ i are completed;

[0014] (5) Stress direction adjustment: Use the specimen rotation device to adjust the load application direction θ j (j = 1, 2, …, M), repeat steps (3) and (4) until the tests under all included angle θj conditions are completed;

[0015] (6) Data fusion stage: Under different stresses (magnitude σ i , direction θ j ), plot the curve of a certain magnetic parameter Mi varying with the angle β, which is the anisotropy result of the magnetic parameter M n in the test disc material;

[0016] Advantageous effects: The device and method of the present invention achieve independent regulation of the stress field and the magnetic field through modular structure design and electromechanical coupling control, solving the problem that it is difficult to conduct anisotropy tests of magnetic Barkhausen noise under arbitrary stresses and rolling directions in a single specimen in traditional methods. At the same time, compared with the traditional hand-held detection method, it effectively eliminates human operation errors. Description of the drawings

[0017] Figure 1 : Schematic structural diagram of the experimental device for testing stress-induced magnetic Barkhausen noise anisotropy;

[0018] Figure 2 : Front view of the device of the present invention;

[0019] Figure 3 : Front view of the excitation magnetic field rotation module;

[0020] Figure 4 : Front view of the disc specimen rotation module;

[0021] Figure 5 : Top view of the multi-angle force-magnetic field loading device;

[0022] Figure 6 : System block diagram of the detection device;

[0023] Figure 7 : Working timing flowchart of the detection device;

[0024] Figure 8 : Anisotropy pole figure of the magnetic Barkhausen noise characteristic parameter MBNEnergy under stress

[0025] Figure 1 Among them, 10. Marble gantry; 20. Marble base; 30. Z-axis electric slide; 40. X-axis electric slide; 50. Y-axis electric slide; 60. Sensor fixing tripod; 70. Magnetic Barkhausen noise sensor; 80. Excitation magnetic field rotation module; 90. Stress loading module; Detailed implementation manners

[0026] The following will be described in detail in conjunction with the accompanying Figures 1 - 5 drawings and specific embodiments of the present invention.

[0027] An experimental device for testing the stress-induced magnetic Barkhausen noise anisotropy is provided in an embodiment of the present invention. The disk specimen rotating device 920 and the uniaxial tension device 910 are used to apply stress loading at any angle, and the electric rotating table 840 and the U-shaped electromagnet 810 are used to apply magnetic field excitation at any angle. By extracting magnetic parameters from the magnetic Barkhausen noise time-domain signals synchronously collected by the magnetic Barkhausen noise sensor 70, the magnetic Barkhausen noise anisotropy law under different stresses and rolling directions is obtained.

[0028] Refer to the accompanying Figures 1 - 2 drawings. The X-axis electric slide 40 and the Y-axis electric slide 50 are arranged on the marble base 20 and are used to adjust the horizontal relative position between the test specimen and the sensor 70. The Z-axis electric guide rail 30 is carried by the gantry 10 and is used to adjust the vertical relative position between the sensor and the surface of the disk specimen. The excitation magnetic field rotation module 80 and the stress loading module 90 are arranged on the X-axis electric slide 40.

[0029] It should be noted that when using this device for magnetic Barkhausen noise detection, the X-axis electric slide 40 and the Y-axis electric slide 50 are adjusted to move the position to be detected of the specimen to the projection area of the magnetic Barkhausen noise sensor 70. The magnetic Barkhausen noise sensor 70 is installed on the Z-axis electric slide 30 through the tripod 60, and the Z-axis electric slide 30 is adjusted to make the sensor 70 contact with the surface of the test specimen. Compared with the method of detecting with a hand-held sensor, the detection stability and detection accuracy are improved.

[0030] Refer to the accompanying Figure 3 drawings. The excitation magnetic field rotation module 80 includes a U-shaped electromagnet 810, an electromagnet limit pressing block 820, an electromagnet clamp 830, a coupling 840, an electric rotating table 850, a Z-axis manual displacement table 860, and an excitation magnetic field rotation module base 870. Specifically, the electromagnet limit pressing block 820 and the electromagnet clamp 830 are connected by bolts to limit the degree of freedom of the U-shaped electromagnet 820; the electromagnet clamp 830 and the electric rotating table 850 are connected by a coupling 840. When using this device, the Z-axis manual displacement table 860 is adjusted to change the lift-off distance between the upper surface of the U-shaped electromagnet 810 and the test specimen; the step distance and the total stroke of the electric rotating table 850 are set to realize the automatic rotation of the magnetic field direction.

[0031] Refer to the accompanying Figure 4, the disk specimen rotation module 920 includes a specimen fixture 921, a specimen limit pressing block 925, a manual rotating table 922, and a rotating table base 923. Specifically, the specimen fixture 921, the manual rotating table 922, and the rotating table base 923 are connected by bolts. The specimen fixture 921 and the specimen limit pressing block 925 are connected by bolts to limit the degrees of freedom of the circular specimen to be tested 924. When using this module, rotate the manual rotating table 922 to control the stress direction.

[0032] See Appendix Figure 5 , which is a top view of the multi-angle force-magnetic field loading device, including an in-situ tensile device 910, a test disk specimen rotation module 920, and an excitation magnetic field rotation module 80.

[0033] See Appendix Figure 6 , in specific implementation, first, place the circular specimen to be tested in the fixture of the specimen rotating device and fix it. Rotate the specimen to change the stress direction, apply a preset tensile load using the in-situ tensile machine, rotate the excitation device to deflect the magnetic field direction in a set step, synchronously trigger the magnetic Barkhausen noise sensor to collect signals and calculate the magnetic parameters (MBN Max 、MBN Energy , etc.). After the detection is completed, unload the fastening bolts of the tensile machine pressing block, use the specimen rotation module to rotate the specimen to the next stress direction and continue the test; finally, perform multi-dimensional data association on different stress states (magnitude, direction) and the corresponding magnetic parameters to construct an anisotropic characteristic map.

[0034] See Appendix Figure 7 , which is a working timing flowchart of the detection device. Use this device to conduct experimental tests on oriented silicon steel materials. The magnetic Barkhausen noise characteristic parameter MBN Energy The anisotropy pole figure is as shown in Appendix Figure 8 . The physical meaning of MBN Energy is: the integral sum of the square of the MBN voltage signal received by the sensor within one excitation period with respect to the time axis.

[0035] The above is only a preferred embodiment of the present invention, and it does not impose any form of limitation on the present invention. Although the present invention has been disclosed above with a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art, without departing from the scope of the technical solution of the present invention, can make some changes or modifications to the above-disclosed technical content to obtain equivalent embodiments with equivalent changes. However, as long as it does not depart from the content of the technical solution of the present invention, any simple modification, equivalent change, and modification made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. An experimental device for testing stress-induced magnetic Barkhausen noise anisotropy, characterized in that: It includes a disc rotating module, an excitation field rotating module, a uniaxial stretching device and a magnetic detection instrument module. The tested sample is a disc, which is supported on the barrel-shaped stage of the disc rotating module. A magnetic Barkhausen noise detection coil is placed just above the center of the disc, and the excitation field rotating module is placed just below the center of the disc. The two end points of a certain diameter line of the rotating disc are clamped by the clamp of the uniaxial stretching device. The loading stress is consistent with the direction of the diameter line and the angle relative to the rolling direction is θ, 0≤θ≤90°; the angle of the excitation field relative to the rolling direction is β, 0≤θ≤360°.

2. The experimental device for testing stress-induced magneto-Barkhausen noise anisotropy according to claim 1, characterized in that: When testing the anisotropy of magnetic Barkhausen noise, the working sequence of the disk rotation module, the excitation field rotation module and the uniaxial stretching device is as follows: Step (1) Within the elastic limit of the material, set the stress loading scheme σ of the uniaxial tensile device on the disc specimen i , i=1,2,…,N; the angle θ between the stress loading direction and the rolling direction j , j = 1, 2, ..., M; the scanning step length of the excitation magnetic field with respect to the rolling direction is β and is Δβ; Step (2) Apply stress σ to the disk i The stepper motor in the excitation field rotation module drives the U-shaped electromagnet to rotate in space according to the set scanning step length Δβ, so that the angle β gradually increases from 0 to 360°. Under each angle β condition, the magnetic detection instrument module performs magnetic Barkhausen noise signal detection and extracts the magnetic parameter M. n , n=1,2,…,S; Step (3) Repeat step (2) until all the set loading stresses σ are completed. i Testing under conditions; Step (4) Remove the fixture and rotate the disc to adjust the angle θ between the stress loading direction and the rolling direction. j , repeat steps (2) and (3) until all angles θ are completed. j Testing under conditions; (5) At a given stress σ i and the angle θ j Under these conditions, plot a magnetic parameter M n The curve of the change with the angle β is the magnetic parameter M in the test disk material. n Anisotropic results.

3. The experimental device for testing stress-induced magneto-Barkhausen noise anisotropy according to claim 1, characterized in that: The disc rotating module includes a barrel-shaped stage, a disc sample limiting pressure block, a manual rotating stage and a rotating stage base. The rotating stage base is fastened to the lower surface of the stretching device by bolts. A V-groove positioning structure is provided on the upper surface of the barrel-shaped stage for carrying the disc sample. The upper surface maintains a coplanar horizontal relationship with the plane of the sample clamping end of the stretching device, and the disc sample maintains a concentric relationship with the barrel-shaped stage.

4. The experimental device for testing stress-induced magnetic Barkhausen noise anisotropy according to claim 2, characterized in that: A disk sample rotating device and a uniaxial stretching device are used to realize stress loading at any angle. An electric rotating table and a U-shaped electromagnet are used to realize magnetic field excitation at any angle. The anisotropy law of magnetic Barkhausen noise under different stresses and rolling directions is obtained by extracting magnetic parameters of the magnetic Barkhausen noise time domain signal synchronously collected by the magnetic Barkhausen noise sensor.

5. The experimental device for testing stress-induced magneto-Barkhausen noise anisotropy according to claim 1, characterized in that: The horizontal relative position adjustment between the test sample and the magnetic Barkhausen noise sensor is achieved through the X-axis electric slide and the Y-axis electric slide; the Z-axis electric guide is carried by the gantry and is used to adjust the vertical relative position of the magnetic Barkhausen noise sensor and the surface of the disc sample; the excitation field rotation module and the stress loading module are configured on the X-axis electric slide.

6. The experimental device for testing stress-induced magnetic Barkhausen noise anisotropy according to claim 5, characterized in that: When using the device for magnetic Barkhausen noise detection, adjust the X-axis electric slide and the Y-axis electric slide to move the test piece to be tested to the projection area of ​​the magnetic Barkhausen noise sensor. The magnetic Barkhausen noise sensor is installed on the Z-axis electric slide through a tripod. Adjust the Z-axis electric slide to make the sensor contact with the surface of the test sample.

7. The experimental device for testing stress-induced magneto-Barkhausen noise anisotropy according to claim 1, characterized in that: The excitation field rotation module includes a U-shaped electromagnet, an electromagnet limit pressure block, an electromagnet fixture, a coupling, an electric rotating table, a Z-axis manual displacement table and an excitation field rotation module base; the electromagnet limit pressure block and the electromagnet fixture are connected by bolts to limit the freedom of the U-shaped electromagnet; the electromagnet fixture and the electric rotating table are connected by a coupling; when using the device, the Z-axis manual displacement is adjusted to change the lifting distance between the upper surface of the U-shaped electromagnet and the test sample; the stepping distance and total stroke of the electric rotating table are set to realize automatic rotation of the magnetic field direction.

8. The experimental device for testing stress-induced magneto-Barkhausen noise anisotropy according to claim 2, characterized in that: The disc sample rotation module includes a sample fixture, a sample limiting pressure block, a manual rotating table and a rotating table base; the sample fixture, the manual rotating table and the rotating table base are connected by bolts, and the sample fixture and the sample limiting pressure block are connected by bolts to limit the degree of freedom of the circular sample to be tested; when using this module, the manual rotating table is rotated to achieve control of the stress direction.

9. The experimental device for testing stress-induced magneto-Barkhausen noise anisotropy according to claim 1, characterized in that: When the experimental device is implemented specifically, first, the circular test sample is placed in the fixture of the specimen rotating device and fixed, the stress direction is changed by rotating the sample, a preset tensile load is applied by an in-situ stretching machine, the excitation device is rotated to set the step-size deflection magnetic field direction, and the magnetic Barkhausen noise sensor is synchronously triggered to collect signals and calculate the magnetic parameters in real time. After the test is completed, the fastening bolts of the stretching machine block are unloaded, and the sample is rotated to the next stress direction by the sample rotation module to continue the test; finally, different stress states are multi-dimensionally associated with corresponding magnetic parameters to construct anisotropic characteristic maps.

10. The experimental device for testing stress-induced magneto-Barkhausen noise anisotropy according to claim 1, characterized in that: This device was used to test the oriented silicon steel material and obtain the characteristic parameter of magnetic Barkhausen noise MBN under stress. Energy Anisotropy pole figure; MBN Energy It is: the integral sum of the square of the MBN voltage signal received by the magnetic Barkhausen noise sensor relative to the time axis within one excitation cycle.

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