An alternating magnetization magnetostrictive flexible probe, detection device and detection method

Abstract

The present application relates to a kind of alternating magnetization magnetostrictive flexible probe, detection device and detection method, wherein, flexible probe includes spiral magnetizing coil and meander coil, the spiral magnetizing coil is set to the part to be measured, the spiral magnetizing coil is configured to produce alternating magnetic field by loading alternating current;The meander coil is set at the position between the spiral magnetizing coil and the part to be measured, the meander coil is configured to produce dynamic magnetic field by loading pulse string current, wherein, the flexible probe produces magnetostrictive vibration based on the alternating magnetic field and dynamic magnetic field, and excites out ultrasonic signal;Using spiral magnetizing coil instead of traditional permanent magnet to produce alternating magnetic field, spiral magnetizing coil and meander coil can be flexibly bent, so as to effectively fit the surface of the part to be measured, especially suitable for the curved surface detection of the part to be measured, effectively reduce the volume of probe while realizing flexible detection.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electromagnetic ultrasonic nondestructive testing, and particularly relates to an alternating-current magnetized magnetostrictive flexible probe, a detection device and a detection method. BACKGROUND

[0002] As a way of electromagnetic ultrasonic testing technology, magnetostriction has the advantages of no need of coupling agent, non-contact, simple structure, etc., and is widely used in the field of nondestructive testing.

[0003] Most of the traditional magnetostrictive probes use permanent magnets or direct current coils to provide a bias magnetic field. The permanent magnet is relatively large in size and cannot be attached to a curved surface. The direct current magnetization current is relatively large, generally reaching several hundred amperes or even kiloamperes, so that the experimental conditions are relatively high. SUMMARY

[0004] Therefore, an alternating-current magnetized magnetostrictive flexible probe, a detection device and a detection method are provided.

[0005] In a first aspect, the present application provides an alternating-current magnetized magnetostrictive flexible probe. The flexible probe comprises a spiral magnetizing coil and a meander coil. The spiral magnetizing coil is arranged on a part to be tested. The spiral magnetizing coil is configured to generate an alternating magnetic field by loading an alternating current. The meander coil is arranged at a position between the spiral magnetizing coil and the part to be tested. The meander coil is configured to generate a dynamic magnetic field by loading a pulse train current. The flexible probe generates magnetostrictive vibration based on the alternating magnetic field and the dynamic magnetic field, and excites an ultrasonic wave signal.

[0006] Further, the flexible probe further comprises a first flexible shell. The first flexible shell is in a cylindrical shape. The spiral magnetizing coil is arranged on the first flexible shell. The first flexible shell is configured to be deformed under the action of an external force to be attached to the surface of the part to be tested.

[0007] Further, the flexible probe further comprises a second flexible shell. The second flexible shell is in a sheet shape. The meander coil is embedded in the second flexible shell through an FPC process. The second flexible shell is configured to be deformed under the action of an external force to be attached to the surface of the part to be tested.

[0008] Further, the flexible probe further comprises a clock module electrically connected to the spiral magnetizing coil and the meander coil. The clock module is configured to control the loading timing of the alternating current and the pulse train current.

[0009] Further, the clock module includes the synchronization circuit and the gate circuit electrically connected with the helical magnetization coil and the meander coil, the synchronization circuit is used for controlling the excitation time of the alternating current and the pulse train current to be the same, and the gate circuit controls the pulse train quantity of the pulse train current based on the frequency of the alternating current and the pulse train current.

[0010] In the second aspect, the application provides a detection device based on an alternating current magnetization magnetostrictive flexible probe, which comprises the alternating current magnetization magnetostrictive flexible probe as described above, and further comprises an alternating current excitation power supply, a pulse train excitation power supply and a signal receiving module, the alternating current excitation power supply is electrically connected with the helical magnetization coil and is used for loading an alternating current to the helical magnetization coil, the pulse train excitation power supply is electrically connected with the meander coil and is used for loading a pulse train current to the meander coil, and the signal receiving module is electrically connected with the meander coil and is used for receiving an induced voltage signal generated by the meander coil.

[0011] In the third aspect, the application provides a detection method based on an alternating current magnetization magnetostrictive flexible probe, which is applied to the detection device based on the alternating current magnetization magnetostrictive flexible probe as described above and comprises the following steps:

[0012] The two flexible probes are arranged at intervals and are both attached to the surface of the part to be detected, one of the flexible probes is an ultrasonic excitation probe, and the other is an ultrasonic receiving probe;

[0013] The alternating current excitation power supply loads an alternating current to the helical magnetization coil in the ultrasonic excitation probe and the ultrasonic receiving probe, thereby generating an alternating magnetic field that alternates in positive and negative directions at two positions on the surface of the part to be detected;

[0014] The pulse train excitation power supply loads a pulse train current to the meander coil in the ultrasonic excitation probe, thereby generating a dynamic magnetic field in the part to be detected;

[0015] The alternating magnetic field and the dynamic magnetic field interact with each other to generate magnetostrictive vibration on the surface of the part to be detected and excite ultrasonic signals;

[0016] The ultrasonic receiving probe receives the ultrasonic waves generated by the ultrasonic excitation probe and the ultrasonic waves reflected from the defects of the part to be detected, and an induced voltage signal is generated in the meander coil in the ultrasonic receiving probe;

[0017] The signal receiving module captures the induced voltage signal and analyzes and processes the signal to obtain a detection result.

[0018] Further, the clock module controls the loading time sequence of the alternating current excitation power supply and the pulse train excitation power supply, wherein the clock module synchronously turns on the alternating current excitation power supply and the pulse train excitation power supply.

[0019] Furthermore, the timing sequence for controlling the AC excitation power supply and the pulse train excitation power supply via the clock module includes:

[0020] The clock module captures the phase of the AC current. When the AC current value increases from zero, the synchronization circuit of the clock module sends a trigger signal to the pulse train excitation power supply.

[0021] When the clock module's gate circuit is turned on, the pulse train excitation power supply generates a preset number of pulse train currents in the tortuous coil of the ultrasonic excitation probe, thereby generating a dynamic magnetic field with a preset duration in the part under test.

[0022] Furthermore, the signal receiving module captures the induced voltage signal and sends it to the oscilloscope.

[0023] Compared with existing technologies, the use of helical magnetizing coils to replace traditional permanent magnets to generate bias magnetic fields allows for flexible bending of both helical magnetizing coils and zigzag coils, effectively conforming to the surface of the part under test. This is particularly suitable for the inspection of curved surfaces of the part under test, effectively reducing the probe size while achieving flexible inspection. The use of helical magnetizing coils to provide alternating magnetic fields means that the vibration influencing factors of magnetostriction force are jointly determined by the alternating magnetic field strength, dynamic magnetic field strength, and magnetostriction amount. This allows for effective excitation of ultrasound at relatively low currents, with a high signal-to-noise ratio. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of the AC magnetized magnetostrictive flexible probe for detecting parts on a plate surface, provided in an embodiment of the present invention.

[0025] Figure 2 This is a schematic diagram of the structure of an AC magnetized magnetostrictive flexible probe for detecting curved surfaces, provided in an embodiment of the present invention.

[0026] Figure 3 This is a schematic diagram of the overall structure of the detection device based on an AC magnetized magnetostrictive flexible probe provided in an embodiment of the present invention.

[0027] Figure 4 Experimental diagrams of the initial and direct waves of SH waves obtained by the detection device based on the AC magnetized magnetostrictive flexible probe provided in this embodiment of the invention for detecting a 1mm thick ferromagnetic 430 stainless steel plate.

[0028] Figure 5 This is a schematic diagram of the detection method based on an AC magnetized magnetostrictive flexible probe provided in an embodiment of the present invention. Detailed Implementation

[0029] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0030] like Figures 1-2 As shown, in a first aspect, the present invention provides an alternating current magnetized magnetostrictive flexible probe 100, the flexible probe 100 including a helical magnetizing coil 110 and a zigzag coil 120, the helical magnetizing coil 110 being attached to the part to be tested and configured to generate an alternating magnetic field by applying an alternating current; the zigzag coil 120 being disposed between the helical magnetizing coil 110 and the part to be tested and configured to generate a dynamic magnetic field by applying a pulse train current, wherein the flexible probe 100 generates magnetostrictive vibration based on the alternating magnetic field and the dynamic magnetic field, and excites an ultrasonic signal.

[0031] In practice, a helical magnetizing coil 110 is used to replace the traditional permanent magnet to generate a bias magnetic field. Both the helical magnetizing coil 110 and the zigzag coil 120 can be flexibly bent, thereby effectively conforming to the surface of the part to be tested, which is especially suitable for the inspection of curved surfaces of the part to be tested. This effectively reduces the size of the probe while achieving flexible inspection. The helical magnetizing coil 110 provides an alternating magnetic field. The vibration influencing factors of the magnetostrictive force are jointly determined by the alternating magnetic field strength, the dynamic magnetic field strength, and the magnetostriction amount. This allows for effective excitation of ultrasound at a relatively low current, and the signal-to-noise ratio is high.

[0032] It is understandable that the parts to be tested are ferromagnetic parts, including ferromagnetic plates, etc.

[0033] In this embodiment, the spiral magnetizing coil 110 is attached to the part under test, and the spiral magnetizing coil 110 is configured to generate an alternating magnetic field by applying an alternating current.

[0034] In one embodiment, the flexible probe 100 further includes a first flexible housing, which is cylindrical in shape. A helical magnetizing coil 110 is wound around the first flexible housing. The first flexible housing is configured to deform under external force to adhere to the surface of the part to be measured. The helical magnetizing coil 110 is enameled wire, which is wound around the outer surface of the first flexible housing to form a helical structure, enabling conformal attachment according to the surface contour of the part to be measured.

[0035] The frequency of the alternating current loaded in the spiral magnetizing coil 110 is approximately between 1 kHz and 100 kHz.

[0036] In this embodiment, the zigzag coil 120 is positioned between the helical magnetizing coil 110 and the part under test. The zigzag coil 120 is configured to generate a dynamic magnetic field by applying a pulse train current. The zigzag coil 120 is a coil with a conductor extending in a serpentine direction, a structure readily apparent to those skilled in the art, and will not be described in further detail here.

[0037] In one embodiment, the flexible probe 100 further includes a second flexible housing, which is sheet-shaped, and the zigzag coil 120 is embedded in the second flexible housing using an FPC process. The second flexible housing is configured to deform under external force to adhere to the surface of the part to be tested.

[0038] The frequency of the pulse train current loaded in the zigzag coil 120 is approximately between 100kHz and 1MHz.

[0039] To facilitate control of the alternating current applied to the spiral magnetization coil 110 and the pulse train current applied to the zigzag coil 120, in one embodiment, the flexible probe 100 further includes a clock module electrically connected to the spiral magnetization coil 110 and the zigzag coil 120, the clock module being configured to control the timing of the application of the alternating current and the pulse train current.

[0040] The clock module includes a synchronization circuit and a gating circuit electrically connected to the spiral magnetization coil 110 and the zigzag coil 120. The synchronization circuit is used to control the excitation time of the AC current and the pulse train current to be the same, and the gating circuit controls the number of pulse trains of the pulse train current based on the frequency of the AC current and the pulse train current.

[0041] SH-mode ultrasonic waves, generated by alternating and dynamic magnetic fields, can detect both surface and internal defects in parts under test. The principle behind generating these ultrasonic waves is as follows: a zigzag coil 120 excites a dynamic magnetic field within the part under test, while a helical magnetizing coil 110 generates an alternating magnetic field. The interaction between the dynamic and alternating magnetic fields, based on the principle of magnetostriction, induces particle vibrations in the ferromagnetic material, thereby forming ultrasonic waves.

[0042] like Figure 1 As shown, when testing part M1 on the board, the zigzag coil 120 is in the shape of a sheet and laid flat on the surface of the part to be tested on the board, and the spiral magnetizing coil 110 is set on the side of the zigzag coil 120 away from the part to be tested on the board.

[0043] like Figure 2 As shown, when inspecting the curved part M2, the zigzag coil 120 is first bent so that it can fit against the curved surface of the part, while the spiral magnetization coil 110 is squeezed so that it forms a curvature that matches the curved surface.

[0044] Understandably, the spiral magnetizing coil 110 and the zigzag coil 120 can be deformed in a corresponding shape according to the surface shape of the part to be tested, thereby achieving flexible detection.

[0045] like Figure 3As shown, the present invention also provides a detection device 200 based on an AC magnetized magnetostrictive flexible probe 100, including the AC magnetized magnetostrictive flexible probe 100 as described above. The detection device 200 further includes an AC excitation power supply 210, a pulse train excitation power supply 221, and a signal receiving module 222. The AC excitation power supply 210 is electrically connected to a spiral magnetization coil 110 and is used to load AC current to the spiral magnetization coil 110. The pulse train excitation power supply 221 is electrically connected to a zigzag coil 120 and is used to load pulse train current to the zigzag coil 120. The signal receiving module 222 is electrically connected to the zigzag coil 120 and is used to receive the induced voltage signal generated by the zigzag coil 120.

[0046] like Figure 3 As shown, the present invention also provides a detection method based on an AC magnetized magnetostrictive flexible probe 100, applied to the detection device 200 based on the AC magnetized magnetostrictive flexible probe 100 as described above, comprising:

[0047] Step S100: Two flexible probes are spaced apart and attached to the surface of the part to be tested, wherein one of the flexible probes is an ultrasonic excitation probe and the other flexible probe is an ultrasonic receiving probe.

[0048] Step S200: The AC excitation power supply applies AC current to the spiral magnetization coils in both the ultrasonic excitation probe and the ultrasonic receiving probe, thereby generating alternating positive and negative magnetic fields at two locations on the surface of the part under test.

[0049] Step S300: The pulse train excitation power supply applies a pulse train current to the tortuous coil in the ultrasonic excitation probe, thereby generating a dynamic magnetic field in the part under test.

[0050] Step S400: The interaction between the alternating magnetic field and the dynamic magnetic field generates magnetostrictive vibration on the surface of the part under test, and excites ultrasonic signals.

[0051] Step S500: The ultrasonic receiving probe receives the ultrasonic waves generated by the ultrasonic excitation probe and the ultrasonic waves reflected from the defects of the part under test. An induced voltage signal is generated in the tortuous coil in the ultrasonic receiving probe.

[0052] Step S600: The signal receiving module captures the induced voltage signal and analyzes and processes it to obtain the detection result.

[0053] In step S100, the ultrasonic excitation probe generates ultrasonic waves based on the principle of magnetostriction, and the ultrasonic receiving probe generates electrical signals based on the principle of inverse magnetostriction.

[0054] In steps S200-S300, the loading timing of AC excitation power supply 210 and pulse train excitation power supply 221 is controlled by the clock module, wherein the clock module synchronously turns on AC excitation power supply 210 and pulse train excitation power supply 221.

[0055] The loading timing of the AC excitation power supply 210 and the pulse train excitation power supply 221 controlled by the clock module includes:

[0056] The clock module captures the phase of the AC current. When the AC current value increases from zero, the synchronization circuit of the clock module sends a trigger signal to the pulse train excitation power supply 221.

[0057] When the clock module's gate circuit is turned on, the pulse train excitation power supply 221 generates a preset number of pulse train currents in the zigzag coil 120 in the ultrasonic excitation probe, thereby generating a dynamic magnetic field with a preset duration in the part under test.

[0058] In step S600, the signal receiving module 222 transmits the captured induced voltage signal to the oscilloscope 230. Both the pulse train excitation power supply 221 and the signal receiving module 222 can be integrated into the excitation / receiving module 220, which includes a signal output terminal 223 connecting the signal receiving module 222 and the signal transmitted to the oscilloscope 230.

[0059] like Figure 1 As shown, in this embodiment of the invention, a spiral magnetizing coil 110 is used to provide an alternating magnetic field, and a zigzag coil 120 carries a pulse train current. The pulse train current is a sinusoidal function modulated by a Hanning window. The pulse train current generates a dynamic magnetic field in the part under test, which interacts with the alternating magnetic field to generate an oscillating magnetostrictive force in the Y direction and generates an SH wave in the X direction.

[0060] At this point, the magnetostrictive force can be expressed by the following formula:

[0061] ;

[0062] in, Magnetostrictive force, The piezomagnetic coefficient is . It is the magnetostrictive quantity. The alternating magnetic field strength, This represents the dynamic magnetic field strength.

[0063] The above-mentioned piezomagnetic coefficient For a constant value, the vibration influencing factors of magnetostrictive force are determined by the alternating magnetic field strength. Dynamic magnetic field strength and magnetostriction Together, they determined that effective excitation of SH waves can be achieved with relatively low current magnetization, and the signal-to-noise ratio is high.

[0064] The magnetic induction intensity of the current-carrying coil at a point P in space is approximately,

[0065] ;

[0066] in The permeability of free space, The number of coil turns. Coil current, This represents the distance of the coil from the central axis. Let P be the distance from the center of the coil.

[0067] The alternating magnetic field strength generated at point P by the helical magnetizing coil ,in, The magnetic field strength at point P caused by the excitation of the helical magnetization coil can be obtained using the formula for the current-carrying coil described above. Similarly, the magnetic field strength at point P of the zigzag coil can be approximated as follows: , The magnetic induction intensity of the zigzag coil at point P can be obtained using the calculation formula for the energized coil described above.

[0068] like Figure 3 As shown, the detection principle of the system of the present invention is as follows: the excitation / receiving device outputs a sinusoidal function modulated by a Hanning window to the zigzag coil 120, the AC power supply outputs AC power to the AC magnetizer, the excitation transducer generates a magnetostrictive force in the part under test based on the magnetostrictive principle to cause particle vibration, thereby generating SH wave, and the receiving transducer generates an electrical signal based on the inverse magnetostrictive principle and displays it in the oscilloscope 230.

[0069] like Figure 4 As shown, the present invention is based on Figure 3 The detection device 200 shown obtained experimental diagrams of the initial wave and direct wave of SH wave in a 1mm ferromagnetic 430 stainless steel plate. The AC magnetizer was supplied with AC current of 30A and 8000Hz. Under relatively low current conditions, signal excitation and reception can be achieved, and a good signal-to-noise ratio can be obtained.

[0070] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. An AC magnetostrictive flexible probe, characterized in that, Flexible probes include: A spiral magnetizing coil is attached to the part under test and is configured to generate an alternating magnetic field by applying an alternating current. A zigzag coil is positioned between the helical magnetizing coil and the part under test, and the zigzag coil is configured to generate a dynamic magnetic field by applying a pulse train current. The flexible probe generates magnetostrictive vibrations based on the alternating magnetic field and the dynamic magnetic field, and excites ultrasonic signals. The flexible probe also includes a clock module electrically connected to the helical magnetization coil and the zigzag coil, the clock module being configured to control the loading timing of the alternating current and the pulse train current; The clock module includes a synchronization circuit and a gating circuit electrically connected to the spiral magnetization coil and the zigzag coil. The synchronization circuit controls the excitation time of the AC current and the pulse train current to be the same, and the gating circuit controls the number of pulse trains of the pulse train current based on the frequency of the AC current and the pulse train current.

2. The AC magnetized magnetostrictive flexible probe according to claim 1, characterized in that, The flexible probe also includes a first flexible housing, which is cylindrical, and the spiral magnetizing coil is wound on the first flexible housing. The first flexible housing is configured to deform under external force so as to adhere to the surface of the part to be tested.

3. The AC magnetized magnetostrictive flexible probe according to claim 1, characterized in that, The flexible probe also includes a second flexible housing, which is sheet-shaped. The zigzag coil is embedded in the second flexible housing using an FPC process. The second flexible housing is configured to deform under external force so as to adhere to the surface of the part to be tested.

4. A detection device based on an AC magnetized magnetostrictive flexible probe, characterized in that, The detection device, comprising the AC magnetized magnetostrictive flexible probe as described in any one of claims 1-3, further comprises: An AC excitation power supply, which is electrically connected to the spiral magnetizing coil, is used to apply AC current to the spiral magnetizing coil; A pulse train excitation power supply, which is electrically connected to the zigzag coil, is used to apply pulse train current to the zigzag coil; A signal receiving module, which is electrically connected to the zigzag coil, is used to receive the induced voltage signal generated by the zigzag coil.

5. A detection method based on an AC magnetized magnetostrictive flexible probe, characterized in that, The detection device based on the AC magnetostrictive flexible probe as described in claim 4 includes: Two flexible probes are spaced apart and attached to the surface of the part to be tested. One of the flexible probes is an ultrasonic excitation probe, and the other flexible probe is an ultrasonic receiving probe. The AC excitation power supply applies AC current to the helical magnetization coils in both the ultrasonic excitation probe and the ultrasonic receiving probe, thereby generating alternating positive and negative magnetic fields at two locations on the surface of the part under test. The pulse train excitation power supply applies a pulse train current to the tortuous coil in the ultrasonic excitation probe, thereby generating a dynamic magnetic field in the part under test. The interaction between the alternating magnetic field and the dynamic magnetic field generates magnetostrictive vibrations on the surface of the part under test, and excites ultrasonic signals. The ultrasonic receiving probe receives ultrasonic waves generated by the ultrasonic excitation probe and ultrasonic waves reflected from the defects in the part under test. An induced voltage signal is generated in the tortuous coil in the ultrasonic receiving probe. The signal receiving module captures the induced voltage signal and analyzes and processes it to obtain the detection result.

6. The detection method based on an AC magnetized magnetostrictive flexible probe according to claim 5, characterized in that, The clock module controls the loading timing of the AC excitation power supply and the pulse train excitation power supply, wherein the clock module synchronously turns on the AC excitation power supply and the pulse train excitation power supply.

7. The detection method based on an AC magnetostrictive flexible probe according to claim 6, characterized in that, The timing sequence for controlling the AC excitation power supply and the pulse train excitation power supply via the clock module includes: The clock module captures the phase of the AC current. When the AC current value increases from zero, the synchronization circuit of the clock module sends a trigger signal to the pulse train excitation power supply. When the clock module's gate circuit is turned on, the pulse train excitation power supply generates a preset number of pulse train currents in the tortuous coil of the ultrasonic excitation probe, thereby generating a dynamic magnetic field with a preset duration in the part under test.

8. The detection method based on an AC magnetostrictive flexible probe according to claim 5, characterized in that, The signal receiving module captures the induced voltage signal and sends it to the oscilloscope.

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