Flexible array eddy current probe for detecting inner wall cracks and use method

Abstract

The invention provides a flexible array eddy current probe for detecting inner wall cracks and a use method, the flexible array eddy current probe comprises a flexible substrate, the flexible substrate is provided with a circuit board, and the circuit board is electrically connected with a crack detection matrix; the crack detection matrix comprises a TR probe unit, the TR probe unit is electrically connected with an eddy current detector, and the eddy current detector is electrically connected with a processing terminal; wherein the TR probe unit is in contact with a turbine blade, the eddy current detector inputs sine excitation current to the TR probe unit, so that the TR probe unit generates a time-varying magnetic field, the time-varying magnetic field induces an eddy current field in the turbine blade, the TR probe unit obtains a differential voltage signal through the eddy current field, and the eddy current detector sends the differential voltage signal to the processing terminal. And processing to obtain crack information. The eddy current probe can realize multi-point simultaneous detection, can be well attached to the surface of a complex test piece, and has the advantages of enhanced defect signal, small lift-off, fast response and high accuracy.

Description

Technical Field

[0001] The invention belongs to the technical field of nondestructive testing, and in particular to a flexible array eddy current probe for detecting inner wall cracks and a use method thereof. Background Art

[0002] The aircraft engine is one of the core components of the aircraft, providing power for the aircraft and is called the heart of the aircraft. The turbine blades in the aircraft engine are one of its key components. Turbine blades working in extreme environments are very likely to produce fatigue cracks caused by thermal mechanical fatigue and vibration fatigue. As the flight time increases, the fatigue cracks will gradually expand and eventually lead to fatigue fracture of the blades, causing flight accidents. Blade fatigue fracture is the final stage of blade fatigue failure. Therefore, when the blades fail due to fatigue, they should be repaired or replaced in time to avoid major safety accidents.

[0003] There are many causes of fatigue failure of turbine blades. Crack defects generated during the manufacturing process of turbine blades are one of the important causes of fatigue failure of blades. Therefore, defect detection during the manufacturing process of blades is of great significance to ensure the service safety of blades and improve the manufacturing level of aircraft engines.

[0004] At present, eddy current testing is often used for turbine blade defect detection and performance evaluation. Although the eddy current testing method can detect turbine blade defects, since the detection equipment uses a single probe for detection, the detection depth is limited to the surface and near-surface of the turbine blade. There are still certain limitations for the detection of defects on the inner wall of the blade. Due to the complex structure of the turbine blade, a general single rigid probe is difficult to fit the surface of the turbine blade, and it is easy to generate lift-off noise during the detection process, resulting in large deviations in the detection results. At the same time, the detection speed of a single probe is relatively low, which makes the detection cycle of the turbine blade long, affecting production efficiency. Summary of the invention

[0005] In order to solve the problem that the detection equipment used in the existing turbine blade production process performs detection through a single probe, resulting in low detection efficiency and low accuracy, the present invention provides a flexible array eddy current probe for detecting inner wall cracks and a method of use, so as to achieve effective detection of cracks on the inner wall of the blade.

[0006] To achieve the above object, the present invention provides the following technical solutions: The present invention proposes a flexible array eddy current probe for detecting inner wall cracks, comprising a flexible substrate, a circuit board is arranged on the flexible substrate, and the circuit board is electrically connected to a crack detection matrix; The crack detection matrix includes a TR probe unit, the TR probe unit is electrically connected to an eddy current detector, and the eddy current detector is electrically connected to a processing terminal; The TR probe unit is in contact with the turbine blade, and the eddy current detector inputs a sinusoidal excitation current into the TR probe unit to make the TR probe unit generate a time-varying magnetic field. The time-varying magnetic field induces an eddy current field in the turbine blade. The TR probe unit obtains a differential voltage signal through the eddy current field, and the eddy current detector sends the differential voltage signal to the processing terminal to process and obtain crack information.

[0007] Preferably, the crack detection matrix comprises a plurality of TR probe unit groups, and the plurality of TR probe unit groups are staggeredly arranged along the width direction of the obtained flexible substrate to form a parallelogram array; The TR probe unit group includes a plurality of TR probe units, and the TR probe units correspond to the eddy current detectors one by one.

[0008] Preferably, a plurality of the TR probe units in the TR probe unit group are arranged linearly, and the number of the TR probe units in each TR probe unit group is the same.

[0009] Preferably, the TR probe unit comprises an excitation coil and a detection coil, and the excitation coil and the detection coil are electrically connected to the eddy current detector respectively.

[0010] Preferably, a pad is provided on the circuit board, and the pad includes a first pad and a second pad, the second pad is provided at the side of the crack detection matrix, and the second pad is electrically connected to the TR probe unit, the first pad is provided at the side of the circuit board, and the first pad is electrically connected to the eddy current detector; A lead is connected between the first pad and the second pad.

[0011] Preferably, the TR probe unit is installed inside the circuit board, and an end of the TR probe unit is flush with an end surface of the circuit board.

[0012] Preferably, the circuit board is a flexible printed circuit board.

[0013] Preferably, the flexible substrate is a silicone pad.

[0014] Preferably, the minimum spacing between the outer contours of the excitation coil and the detection coil ranges from 1.8 mm to 2.2 mm.

[0015] The present invention proposes a method for using a flexible array eddy current probe for detecting inner wall cracks, which is applied to the above-mentioned flexible array eddy current probe for detecting inner wall cracks and is characterized in that it includes the following steps: Place the outer end of the TR probe unit against the surface of the turbine blade; The TR probe unit is moved, wherein the TR probe unit generates a time-varying magnetic field based on a sinusoidal excitation current input by an eddy current detector, wherein the time-varying magnetic field induces eddy currents in turbine blades, and the eddy currents generate a feedback magnetic field opposite to the time-varying magnetic field, and the TR probe unit generates a differential voltage signal based on the feedback magnetic field; The eddy current detector acquires the differential voltage signal and transmits it to a processing terminal for processing to obtain crack information of the turbine blade.

[0016] Compared with the prior art, the present invention has the following beneficial technical effects: The present invention proposes a flexible array eddy current probe for detecting inner wall cracks. The eddy current probe realizes comprehensive and close detection of the inner wall of a turbine blade by adopting a flexible substrate to carry a circuit board and a crack detection matrix, thereby enhancing the detection coverage and improving the detection efficiency. The synergistic effect of the TR probe unit and the eddy current detector can accurately input a sinusoidal excitation current and generate a time-varying magnetic field, effectively induce an eddy current field in the turbine blade, and then reflect the existence of cracks through a differential voltage signal. The processing terminal efficiently processes the received signal and quickly analyzes the crack information. Compared with traditional eddy current detection probes, the eddy current probe can realize multi-point simultaneous detection, can better fit the surface of complex specimens, and has the advantages of defect signal enhancement, small lift-off, fast response, high accuracy, etc.

[0017] Furthermore, the crack detection matrix in the eddy current probe adopts multiple TR probe unit groups arranged in a parallelogram array in an offset manner, which not only expands the detection coverage but also enhances the adaptability to the inner wall of complex shape. Each TR probe unit group contains the same number of TR probe units, which are arranged linearly and correspond one-to-one with the eddy current detector, ensuring the stability and consistency of the detection signal, so that the probe can more accurately capture the slight changes in the eddy current field, thereby more accurately identifying crack information. The layout of the parallelogram array also improves the detection speed, shortens the detection cycle, reduces the detection cost, improves the detection performance, and broadens the application scope. It is suitable for the detection of turbine blades of various shapes and materials, bringing a higher level of intelligence and automation to the field of industrial detection.

[0018] Furthermore, the TR probe unit in this eddy current probe has built-in excitation coil and detection coil, both of which are electrically connected to the eddy current detector, enhancing the sensitivity and reliability of crack detection. The excitation coil is responsible for generating a time-varying magnetic field to excite the eddy current field in the turbine blades; the detection coil accurately captures the differential voltage signal generated by the change in the eddy current field. The two work together to not only improve the detection accuracy, but also ensure the stability and accuracy of the detection signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1A schematic diagram of the structure of a flexible array eddy current probe for detecting inner wall cracks proposed by the present invention; Figure 2 This is a schematic diagram of the structure of a silicone pad in a flexible array eddy current probe for detecting inner wall cracks proposed by the present invention; Figure 3 A schematic diagram of the structure of a flexible printed circuit board in a flexible array eddy current probe for detecting inner wall cracks proposed by the present invention; Figure 4 A schematic diagram of the arrangement of the coils of a flexible array eddy current probe in a flexible array eddy current probe for detecting inner wall cracks proposed by the present invention; Figure 5 A schematic diagram of the use principle of a flexible array eddy current probe for detecting inner wall cracks proposed by the present invention; In the accompanying drawings: 1. flexible substrate; 2. circuit board; 3. first excitation coil; 4. first detection coil; 5. third excitation coil; 6. third detection coil; 7. lead wire; 8. fourth detection coil; 9. fourth excitation coil; 10. second detection coil; 11. second excitation coil; 12. soldering pad; 13. TR probe unit. DETAILED DESCRIPTION

[0020] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.

[0021] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0022] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0023] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0024] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0025] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0026] The present invention proposes a flexible array eddy current probe for detecting inner wall cracks, such as Figure 1~Figure 4 As shown, it includes a flexible substrate 1, a circuit board 2 is arranged on the upper end surface of the flexible substrate 1, and the circuit board 2 is electrically connected to a crack detection matrix; the crack detection matrix includes a TR probe unit 13, the TR probe unit 13 is electrically connected to an eddy current detector, and the eddy current detector is electrically connected to a processing terminal; wherein, the TR probe unit 13 is in contact with the turbine blade, and the eddy current detector inputs a sinusoidal excitation current to the TR probe unit 13, so that the TR probe unit 13 generates a time-varying magnetic field, and the time-varying magnetic field induces an eddy current field in the turbine blade, and the TR probe unit 13 obtains a differential voltage signal through the eddy current field, and the eddy current detector sends the differential voltage signal to the processing terminal, processes and obtains crack information.

[0027] like Figure 1 and Figure 2 As shown, the flexible substrate 1 is rectangular and the flexible substrate 1 is a silicone pad. The silicone pad has a certain flexibility and can bend freely so as to better fit the surface of the test piece. At the same time, because it also has the advantages of insulation, compressibility, environmental protection, high temperature resistance, etc., the eddy current probe can fully fit the turbine blades with complex surfaces and has higher sensitivity and accuracy.

[0028] The crack detection matrix includes a plurality of TR probe unit groups, which are staggered along the width direction of the flexible substrate 1 to form a parallelogram array, and the TR probe unit group includes a plurality of TR probe units 13, and the TR probe units 13 correspond to the eddy current detectors one by one. The plurality of TR probe units 13 in the TR probe unit group are linearly arranged, and the number of TR probe units 13 in each TR probe unit group is the same. The TR probe unit 13 includes an excitation coil and a detection coil, and the excitation coil and the detection coil are electrically connected to the eddy current detector respectively. For example, Figure 1 , Figure 3 and Figure 4 As shown, the circuit board 2 is a flexible printed circuit board, and a plurality of first mounting holes are arranged at the center position on the upper end surface of the circuit board 2. The minimum distance between the contours of two adjacent first mounting holes ranges from 1.8 mm to 2.2 mm. In this embodiment, 2 mm is preferred. Two groups of the plurality of first mounting holes are arranged along the length direction of the circuit board 2. The two groups of first mounting holes are staggered along the width direction of the circuit board 2 to form a parallelogram array. Second mounting holes are arranged at positions corresponding to the first mounting holes on the flexible substrate 1. An excitation coil or a detection coil is installed in the second mounting hole and the corresponding first mounting hole. The ends of the excitation coil and the detection coil are flush with the end surface of the circuit board 2. The first mounting hole on the flexible printed circuit board is aligned with the second mounting hole on the silicone pad and then glued and fixed. Both are flexible and can be bent at will, so as to realize accurate detection of complex surfaces. In this embodiment, four TR probe units 13 are installed at the center position of the circuit board 2. The four The TR probe units 13 form a parallelogram array; the four TR probe units 13 are the first probe unit, the second probe unit, the third probe unit and the fourth probe unit in sequence; the first probe unit includes the first excitation coil 3 and the first detection coil 4; the second probe unit includes the second excitation coil 11 and the second detection coil 10; the third probe unit includes the third excitation coil 5 and the third detection coil 6; the fourth probe unit includes the fourth excitation coil 9 and the fourth detection coil 8; the first excitation coil 3, the first detection coil 4, the third excitation coil 5 and the third detection coil 6 form a group, which are installed in a corresponding group of mounting holes on the circuit board 2, and the first excitation coil 3, the second excitation coil 11, the third excitation coil 5 and the fourth excitation coil 9 are located at positions such as Figure 4As shown, the arrangement of the excitation coils is symmetrical, alternately forming a parallel oblique line structure; the second excitation coil 11, the second detection coil 10, the fourth excitation coil 9 and the fourth detection coil 8 form a group, which are installed in another group of corresponding mounting holes on the circuit board 2, and the first detection coil 4 and the second detection coil 10 and the third detection coil 6 and the fourth detection coil 8 are arranged similarly to the excitation coils, forming the same parallel oblique line structure, the second excitation coil 11, the second detection coil 10, the fourth excitation coil 9 and the fourth detection coil 8 are installed adjacent to each other in this order, and the two groups are staggered to form a parallelogram-shaped array; during the detection process, the excitation coil or the detection coil of the TR probe unit 13 contacts the surface of the turbine blade, and the excitation coil generates a time-varying magnetic field under the action of the sinusoidal excitation current input by the eddy current detector, and the time-varying magnetic field induces an eddy current field in the turbine blade, wherein the eddy current field is mainly concentrated in the detection area on the blade surface, and the distribution presents a ring-shaped or local vortex-shaped closed current. Since the excitation coils are arranged in parallel, the eddy current field has directionality, and it is in multiple components The TR probe units 13 of the present invention overlap each other, thereby enhancing the coverage of the detection. In the defect-free area, the eddy current field in the turbine blade is evenly distributed, and the amplitude and direction are relatively stable. The signal sensed by the detection coil is symmetrical and stable. When the probe moves to the area where there is a crack on the turbine blade, the eddy current field in the turbine blade will be cut off or redistributed by the time-varying magnetic field, the density of the eddy current field will be reduced, and the direction will be shifted, thereby forming an abnormal eddy current field. A differential voltage signal is generated at both ends of the detection coil, so that the detection coil can monitor the changes in the eddy current field in real time. The four TR probe units 13 work together to cover the entire detection area and improve the detection efficiency. In this eddy current probe, the turbine blade is detected by the TR probe units 13 arranged in an array, so as to realize comprehensive detection of the turbine blade detection area and improve the detection efficiency and accuracy. The multiple TR probe units 13 arranged in a parallelogram array can be more evenly distributed on the surface of the turbine blade, thereby realizing comprehensive detection of the blade, reducing the detection blind area and improving the detection accuracy and reliability.

[0029] like Figure 1 and Figure 3As shown, a pad 12 is arranged on the upper end surface of the circuit board 2, and the pad 12 includes a plurality of first pads and a plurality of second pads. The plurality of second pads are symmetrically arranged along the length direction of the circuit board 2 on the side of the crack detection matrix, that is, on the front and back sides of the crack detection matrix. The second pads are electrically connected to the excitation coil or the detection coil of the TR probe unit 13, and one second pad is electrically connected to one excitation coil or detection coil. The plurality of first pads are symmetrically arranged along the length direction of the circuit board 2 on the side of the circuit board 2, and the second pads correspond to the first pads one by one. A lead 7 is connected between the second pads and the corresponding first pads. The first pad is electrically connected to the eddy current detector, and the first pad corresponding to the second pad connected to the excitation coil of a TR probe unit 13 is connected to one end of the eddy current detector, so that the eddy current detector inputs a sinusoidal excitation current to the excitation coil, and the first pad corresponding to the second pad connected to the detection coil of the TR probe unit 13 is connected to the other end of the eddy current detector to obtain the differential voltage signal generated by the detection coil.

[0030] The present invention proposes a method for using a flexible array eddy current probe for detecting inner wall cracks, which is applied to the above-mentioned flexible array eddy current probe for detecting inner wall cracks, and comprises the following steps: The outer end of the TR probe unit 13 is attached to the surface of the turbine blade; The TR probe unit 13 is moved. The TR probe unit 13 generates a time-varying magnetic field based on the sinusoidal excitation current input by the eddy current detector. The time-varying magnetic field induces eddy currents in the turbine blades. The eddy currents generate a feedback magnetic field opposite to the time-varying magnetic field. The TR probe unit 13 generates a differential voltage signal based on the feedback magnetic field. The eddy current detector obtains the differential voltage signal and transmits it to the processing terminal to obtain the crack information of the turbine blade.

[0031] The specific implementation steps are as follows: The eddy current probe is placed on the surface of the turbine blade. The moving direction of the TR probe unit 13 composed of the excitation coil and the detection coil is parallel to the moving direction of the probe, that is, the excitation coil and the detection coil adopt a movement mode of passing through the crack area in sequence, such as Figure 5 As shown, the flexible array probe is completely fitted with the surface of the turbine blade, and then the back crack of the turbine blade is scanned. When scanning the crack, the exciting coil and the detecting coil pass through the crack one after the other; During scanning, the eddy current detector passes a sinusoidal excitation current into the first excitation coil 3, the second excitation coil 11, the third excitation coil 5 and the fourth excitation coil 9. The excitation frequency is 20kHz, the excitation voltage is 4.25V, and the gain is 20dB. A time-varying magnetic field is generated in the excitation coil. When the excitation coil is close to the turbine blade to be tested, the time-varying magnetic field will induce an eddy current field in the blade. The eddy current field generates a feedback magnetic field opposite to the time-varying magnetic field generated by the excitation coil. The feedback magnetic field will in turn affect the detection coil, so that a differential voltage signal is generated at both ends of the detection coil, and the eddy current detector obtains the differential voltage signal. Collect the differential voltage signals generated at both ends of the first detection coil 4, the second detection coil 10, the third detection coil 6 and the fourth detection coil 8 under the influence of the eddy current field at the crack to obtain the number of turns of the detection coil , imaginary number , excitation signal angular frequency , detect the change in magnetic induction intensity caused by the eddy current change caused by the crack at the coil , detection coil The plane enclosed by the turns of wire ,flat Perimeter And detect the magnetic potential disturbance of the field point on the coil , the differential voltage signal at both ends of the detection coil is calculated by the calculation formula of the induced electromotive force change, and the eddy current detector transmits the differential voltage signal obtained by the detection calculation to the computer for subsequent processing through the processing terminal; The calculation formula for the change of induced electromotive force is:

[0032] in, is a differential voltage signal, In order to detect the change of magnetic induction intensity of the coil, is an imaginary number, is the excitation signal angular frequency, To detect the number of coil turns, To detect coil The plane enclosed by the turns of wire, For plane Perimeter And detect the magnetic potential loss disturbance at the field point on the coil.

[0033] Multi-channel data is collected, that is, each TR probe unit 13 in the eddy current probe collects data independently, and multiple TR probe units 13 constitute a multi-channel acquisition system, covering the entire inspection area of ​​the turbine blade. All signals are transmitted to the processing terminal through the eddy current detector for data processing. , detect the induced voltage of the coil at the defect-free position The detection sensitivity S of the probe is calculated using the sensitivity S calculation formula. If the detection sensitivity S is greater than 5%, it is determined that there is a crack in the turbine blade. The processing terminal generates a two-dimensional eddy current signal distribution map of the blade detection area based on the differential voltage signal, and then identifies the location, shape and size of the crack to obtain the crack information.

[0034] The calculation formula of sensitivity S is: ×100% in, To detect the induced voltage when the coil passes through the defect, To detect the induced voltage of the coil at the defect-free point.

[0035] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the attached claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention. Any figure mark in the claims should not be regarded as limiting the claims involved.

[0036] In addition, it should be understood that although this specification is described in accordance with the implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation modes that can be understood by those skilled in the art. The above content is only to illustrate the technical idea of ​​the present invention, and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution according to the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A flexible array eddy current probe for detecting inner wall cracks, characterized in that: It comprises a flexible substrate (1), a circuit board (2) being arranged on the flexible substrate (1), and the circuit board (2) being electrically connected to a crack detection matrix; The crack detection matrix comprises a TR probe unit (13), the TR probe unit (13) is electrically connected to an eddy current detector, and the eddy current detector is electrically connected to a processing terminal; The TR probe unit (13) is in contact with a turbine blade, the eddy current detector inputs a sinusoidal excitation current into the TR probe unit (13) so that the TR probe unit (13) generates a time-varying magnetic field, the time-varying magnetic field induces an eddy current field in the turbine blade, the TR probe unit (13) obtains a differential voltage signal through the eddy current field, and the eddy current detector sends the differential voltage signal to the processing terminal to process and obtain crack information.

2. A flexible array eddy current probe for detecting inner wall cracks according to claim 1, characterized in that: The crack detection matrix comprises a plurality of TR probe unit groups, wherein the plurality of TR probe unit groups are staggeredly arranged along the width direction of the obtained flexible substrate (1) to form a parallelogram array; The TR probe unit group comprises a plurality of TR probe units (13), and the TR probe units (13) correspond one to one to the eddy current detectors.

3. A flexible array eddy current probe for detecting inner wall cracks according to claim 2, characterized in that: A plurality of the TR probe units (13) in the TR probe unit group are arranged linearly, and the number of the TR probe units (13) in each TR probe unit group is the same.

4. The flexible array eddy current probe for detecting inner wall cracks according to claim 2, characterized in that: The TR probe unit (13) comprises an excitation coil and a detection coil, and the excitation coil and the detection coil are electrically connected to the eddy current detector respectively.

5. The flexible array eddy current probe for detecting inner wall cracks according to claim 1, characterized in that: The circuit board (2) is provided with a soldering pad (12), the soldering pad (12) comprising a first soldering pad and a second soldering pad, the second soldering pad being provided at a side of the crack detection matrix, the second soldering pad being electrically connected to the TR probe unit (13), the first soldering pad being provided at a side of the circuit board (2), the first soldering pad being electrically connected to the eddy current detector; A lead (7) is connected between the first pad and the second pad.

6. The flexible array eddy current probe for detecting inner wall cracks according to claim 2, characterized in that: The TR probe unit (13) is installed inside the circuit board (2), and an end of the TR probe unit (13) is flush with an end surface of the circuit board (2).

7. A flexible array eddy current probe for detecting inner wall cracks according to claim 6, characterized in that: The circuit board (2) is a flexible printed circuit board.

8. The flexible array eddy current probe for detecting inner wall cracks according to claim 1, characterized in that: The flexible substrate (1) is a silicone pad.

9. The flexible array eddy current probe for detecting inner wall cracks according to claim 1, characterized in that: The minimum spacing between the outer contours of the excitation coil and the detection coil is in the range of 1.8 mm to 2.2 mm.

10. A method for using a flexible array eddy current probe for detecting inner wall cracks, applied to a flexible array eddy current probe for detecting inner wall cracks as claimed in any one of claims 1 to 9, characterized in that: The following steps are involved: The outer end of the TR probe unit (13) is placed against the surface of the turbine blade; Moving the TR probe unit (13), the TR probe unit (13) generating a time-varying magnetic field based on a sinusoidal excitation current input by an eddy current detector, the time-varying magnetic field inducing eddy currents in turbine blades, the eddy currents generating a feedback magnetic field opposite to the time-varying magnetic field, and the TR probe unit (13) generating a differential voltage signal based on the feedback magnetic field; The eddy current detector acquires the differential voltage signal and transmits it to a processing terminal for processing to obtain crack information of the turbine blade.

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