Aero-engine blade in-service in-situ electromagnetic acoustic detection system and method

Abstract

The invention relates to the technical field of nondestructive testing of engine blades, and discloses an in-service in-situ electromagnetic acoustic detection system and method for aero-engine blades, which adopt an integrated design of an array eddy current sensor and an array surface wave sensor, ensure that dangerous cracks exposed out of a blade tenon can be reliably detected by an eddy current method, and meanwhile, improve the detection accuracy of the blade tenon. The internal fatigue damage can also be detected by an ultrasonic method, so that the engineering application problem that the embedded fatigue crack of the blade tenon of the aero-engine cannot be effectively detected in situ is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of non-destructive testing, and in particular to an in-service in-situ electromagnetic acoustic testing system and method for aircraft engine blades. Background Art

[0002] As the "heart" of an aircraft, the structural integrity of its blades directly affects flight safety and engine performance. However, engine blades are prone to stress fatigue and micro-motion damage caused by long-term operation in extreme environments of high temperature, high speed, high pressure and complex alternating loads, which can lead to cracks or even fractures. Figure 1 Eddy current testing technology can achieve effective in-situ detection of cracks in the blade body A / B / C area and the shallow surface of the tenon. However, when the crack occurs in the tenon embedded in the mortise and has not yet extended to the surface (such as the attached Figure 1 There is currently no effective detection method for this area (the D area in the middle). This technical bottleneck prevents the timely detection of early cracks that may exist in the hidden areas of the mortise and tenon groove, posing a major threat to engine safety. Therefore, developing in-situ detection methods for this area is a key technical challenge that urgently needs to be overcome. Summary of the Invention

[0003] To solve the above problems, the present invention provides an in-service in-situ electromagnetic acoustic detection system and method for aircraft engine blades. The present invention is implemented as follows:

[0004] An in-service in-situ electromagnetic acoustic detection system for aircraft engine blades, comprising:

[0005] The electromagnetic acoustic integrated detector 100 includes array eddy current detection function and ultrasonic surface wave detection function;

[0006] The electromagnetic acoustic detection probe 200 is designed as a contoured array eddy current-array ultrasonic surface wave integrated probe;

[0007] The electromagnetic acoustic detection probe 200 includes a handle portion 210, a probe portion 220, a contour array eddy current detection module 230, an array ultrasonic surface wave detection module 240 and a universal hinge structure 250;

[0008] The probe portion 220 is designed as a hollow cavity, one end of which is fixedly connected to the handle portion 210, and the other end is rotatably connected to the contour array eddy current detection module 230 through a universal hinge structure 250;

[0009] The contour array eddy current detection module 230 includes a contour array eddy current detection sensor 231 and a three-point positioning structure 232, which is used to fit the R angle surface of the root of the blade tenon;

[0010] The three-point positioning structure 232 includes a first pressing rod 2321, a second pressing rod 2322, a third pressing rod 2323, and a first elastic conductive layer 2324 connecting and fixing the three pressing rods.

[0011] The array ultrasonic surface wave detection module 240 includes an array ultrasonic surface wave detection sensor 241 and a coupling water delivery device 242, which is used to fit the blade surface above the root of the blade tenon;

[0012] The coupled water transfer device 242 includes a first micro water bladder 2421 , a micro water transfer channel 2422 , a second micro water bladder 2423 , a micro water permeable structure 2424 and a thin fabric layer 2425 ;

[0013] The first micro water bag 2421 is fixedly disposed on one side of the handle portion 210 via a first connecting end 2421-1 and a second connecting end 2421-2;

[0014] The micro water delivery channel 2422 is provided in the cavity of the probe portion 220, one end of which is connected to the first micro water bag 2421 through the first through hole 2201 on the probe portion 220, and the other end is connected to the second micro water bag 2423 also provided in the cavity of the probe portion 220;

[0015] The micro water seepage structure 2424 includes: a micro water storage channel 2424-1 communicating with the second micro water bag 2423, a fixing layer 2424-2 and a plurality of micro water seepage channels 2424-3;

[0016] The fixed layer 2424-2 is evenly distributed with through holes corresponding to the plurality of micro water seepage channels 2424-3;

[0017] The thin cloth layer 2425 is fixedly arranged on the detection surface of the array ultrasonic surface wave detection sensor 241;

[0018] The micro water seepage structure 2424 is integrated above the array ultrasonic surface wave detection sensor 241, and the water outlets of the multiple micro water seepage channels 2424-3 are connected to the thin cloth layer (2425).

[0019] Furthermore, the contoured array eddy current detection sensor 231 includes:

[0020] The contoured coil bobbin 2311 is adapted to fit the concave curvature of the surface to be inspected and matches the R angle of the root of the tenon;

[0021] The coil array 2312 is configured as an eight-channel coil array and is embedded in the contoured coil frame 2311;

[0022] The micro spring pressing structure is arranged on the back of the contoured coil frame 2311 and includes spiral springs arranged in a matrix and a second elastic conductive layer covering the spring array.

[0023] Furthermore, the plurality of micro water seepage channels 2424 - 3 are evenly distributed on the four sides of the inner shell of the array ultrasonic surface wave detection sensor 241 .

[0024] An in-service in-situ electromagnetic acoustic detection method for aircraft engine blades, using the above-mentioned detection system, includes the following steps:

[0025] S1. Probe positioning and coupling:

[0026] The contoured array eddy current detection sensor 231 is placed on the R-angle surface of the root of the blade tenon by moving the probe portion 220, and the detection surface is automatically pressed against the R-angle surface of the root of the blade tenon by the three-point positioning structure 232;

[0027] Rotate the universal hinge structure 250 to adjust the angle of the array ultrasonic surface wave detection module 240 so that the array ultrasonic surface wave detection sensor 241 is in contact with the blade surface above the root of the blade tenon;

[0028] Pressing the first micro water bag 2421 causes water to flow through the micro water channel 2422 to the second micro water bag 2423 , and then penetrate the thin fabric layer 2425 through the micro water permeable structure 2424 to form an ultrasonically coupled water film.

[0029] S2. Synchronous scanning and detection

[0030] S2.1 Array Eddy Current Testing

[0031] The drive coil array 2312 emits a multi-frequency excitation signal, moves and scans along the R-angle surface of the blade tenon root, and collects eddy current detection signals of cracks on the blade tenon root surface in real time;

[0032] S2.2 Array Ultrasonic Surface Wave Detection

[0033] The array ultrasonic surface wave detection sensor 241 transmits a directional surface wave beam, moves and scans along the blade surface above the root of the blade tenon, and receives the ultrasonic detection signal of the internal crack of the blade tenon root in real time;

[0034] The array eddy current detection and the array ultrasonic surface wave detection are performed synchronously on the same scanning path.

[0035] S3. Collaborative Crack Identification

[0036] S3.1 Surface crack determination

[0037] Extract the phase mutation points and amplitude abnormal areas of the eddy current detection signal and mark them as the surface crack locations;

[0038] S3.2 Internal crack determination

[0039] In the scanned area with no abnormalities during eddy current testing, the attenuation information of the ultrasonic testing signal is extracted. When it exceeds the preset threshold, it is marked as the internal crack location;

[0040] S3.3 Comprehensive Positioning

[0041] The surface crack positions and internal crack positions are mapped to the same spatial coordinate system, and the crack distribution map is output.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] The present invention adopts an integrated design of array eddy current sensors and array surface wave sensors, which ensures that dangerous cracks exposed outside the blade tenon can be reliably detected by the eddy current method. At the same time, internal fatigue damage can also be detected by the ultrasonic method, solving the engineering application problem that buried fatigue cracks in the tenon of aircraft engine blades cannot be effectively detected in situ.

[0044] In response to actual detection conditions, an innovative integrated probe combining a contoured array eddy current and array ultrasonic surface wave was designed. The contoured array eddy current detection sensor, through the ingenious design of a contoured skeleton, a three-point positioning structure, and a micro-spring low-pressure structure, enables it to conform to the R-angle surface of the root of the blade tenon. The universal structure also enables the array ultrasonic surface wave detection sensor to conform to the blade surface above the root of the blade tenon, solving the positioning problem of the contoured array eddy current detection sensor and the array ultrasonic surface wave detection sensor of the integrated probe in a narrow space. At the same time, an innovative coupling water delivery device for the array ultrasonic surface wave detection sensor was designed. The ingenious design of a micro water bag, a micro water seepage structure, and a thin cloth layer allows a uniform water film to be formed on the surface of the array ultrasonic surface wave detection sensor without affecting the array eddy current detection, solving the coupling problem of the array ultrasonic surface wave detection sensor of the integrated probe in a narrow space. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the examples of the present invention or the technical solutions in the prior art or the drawings required for the description of the prior art, a brief introduction is given. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0046] Figure 1 This is the defect distribution diagram of the blade.

[0047] Figure 2 Schematic diagram of the detection working conditions for this implementation.

[0048] Figure 3 Schematic diagram of the detection system structure implemented in this paper.

[0049] Figure 4 Schematic diagram of the array detection module of this embodiment.

[0050] Figure 5 FIG. 4 is a schematic diagram of the external structure of the array ultrasonic surface wave detection module of this embodiment.

[0051] Figure 6 FIG. 4 is a schematic diagram of an array ultrasonic surface wave detection module according to this embodiment.

[0052] Figure 7 Schematic diagram of the micro water seepage structure of this embodiment.

[0053] In the picture:

[0054] 100-Electromagnetic and acoustic comprehensive detector;

[0055] 200-Electromagnetic Acoustic Detection Probe;

[0056] 210-handle part;

[0057] 220-probe portion, 2201-first through hole;

[0058] 230 - contour array eddy current detection module, 231 - contour array eddy current detection sensor, 2311 - contour coil skeleton, 2312 - coil array, 232 - three-point positioning structure, 2321 - first pressure rod, 2322 - second pressure rod, 2323 - third pressure rod, 2324 - first elastic conductive layer;

[0059] 240 - array ultrasonic surface wave detection module, 241 - array ultrasonic surface wave detection sensor, 242 - coupled water transfer device, 2421 - first micro water bladder, 2421-1 - first connecting end, 2421-2 - second connecting end, 2422 - micro water transfer channel, 2423 - second micro water bladder, 2424 - micro water seepage structure, 2424-1 - micro water storage channel, 2424-2 - fixed layer, 2424-3 - micro water seepage channel, 2425 - thin fabric layer;

[0060] 250-Universal articulated structure. DETAILED DESCRIPTION

[0061] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention.

[0062] In the description of the present invention, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, features specified as "first" or "second" may explicitly or implicitly include one or more of the features.

[0063] As attached Figure 1 As shown, under extreme working conditions, the blade body, tenon root, blade tenon, and tenon-groove joint of an aircraft engine blade become high-risk areas for crack initiation due to stress concentration and micro-motion mode. For the inspection of blades, the exposed area can be reliably detected by eddy current detection, but for cracks embedded in the hidden area of ​​the tenon and groove, especially early cracks that have not extended to the surface, the eddy current method is almost impossible to identify. The traditional ultrasonic method can be used to detect internal defects, but due to the need for coupling agents and the influence of the blade tenon and groove shape on the sound waves, the detection signal is easily misjudged or missed. Based on this, the present embodiment provides an in-service in-situ electromagnetic acoustic detection system for aircraft engine blades, comprising:

[0064] The electromagnetic acoustic integrated detector 100 includes array eddy current detection function and ultrasonic surface wave detection function;

[0065] The electromagnetic acoustic detection probe 200 is designed as a contoured array eddy current-array ultrasonic surface wave integrated probe;

[0066] The electromagnetic acoustic detection probe 200 includes a handle portion 210, a probe portion 220, a contour array eddy current detection module 230, an array ultrasonic surface wave detection module 240 and a universal hinge structure 250;

[0067] The probe portion 220 is designed as a hollow cavity, and the interior of the hollow cavity is used to accommodate various detection signal lines, control lines and micro water channels 2422 of the coupling agent in the array ultrasonic surface wave detection module.

[0068] One end of the probe is fixedly connected to the handle portion 210, while the other end is rotatably connected to the contour array eddy current detection module 230 via a universal hinge structure 250. This universal hinge structure 250 enables relative rotation between the contour array eddy current detection module, the probe, and components such as the array ultrasonic surface wave detection sensor mounted on the probe's sidewall. In this embodiment, the universal hinge structure utilizes a ball joint, comprising a ball head and a ball head seat. Furthermore, the ball head is designed with several ball bearing grooves along its longitudinal axis, within which balls are positioned, to enhance smooth adjustment between the ball head and the ball head seat.

[0069] The contour array eddy current detection module 230 includes a contour array eddy current detection sensor 231 and a three-point positioning structure 232, which is used to fit the R angle surface of the root of the blade tenon;

[0070] The three-point positioning structure 232 includes a first pressure rod 2321, a second pressure rod 2322, a third pressure rod 2323 and a first elastic conductive layer 2324 connecting and fixing the three pressure rods, which are evenly distributed on the back of the contoured array eddy current detection sensor 231; the three mechanical pressures and the elastic conductive layer are used to balance the pressure, ensuring that the contoured array eddy current detection sensor fits tightly to the irregular surface.

[0071] The use of contour-profiling multi-channel eddy current detection sensors, contour-profiling structures and positioning structures with elastic conduction can dynamically fit complex curved surfaces to improve the accuracy of sensor positioning; each channel is independently excited and received, and multiple channels are scanned in parallel to improve detection efficiency.

[0072] The array ultrasonic surface wave detection module 240 includes an array ultrasonic surface wave detection sensor 241 and a coupling water delivery device 242, which is used to fit the blade surface above the root of the blade tenon and transmit a directional surface wave beam to the part to be tested through the array ultrasonic surface wave detection sensor 241.

[0073] A special coupling water delivery device 242 is provided to achieve the delivery of coupling agent in the ultrasonic surface wave detection method in a narrow space. Specifically, the coupling water delivery device 242 includes a first micro water capsule 2421, a micro water delivery channel 2422, a second micro water capsule 2423, a micro water permeable structure 2424, and a thin fabric layer 2425.

[0074] The first micro water capsule 2421 is fixedly arranged on one side of the handle portion 210 through a first connection end 2421-1 and a second connection end 2421-2; preferably, the first micro water capsule can be selectively injected with deionized water or silicone oil-based coupling agent according to the requirements of the detection working conditions.

[0075] The micro water delivery channel 2422 is provided in the cavity of the probe portion 220, one end of which is connected to the first micro water bag 2421 through the first through hole 2201 on the probe portion 220, and the other end is connected to the second micro water bag 2423 also provided in the cavity of the probe portion 220;

[0076] The micro water seepage structure 2424 includes: a micro water storage channel 2424-1 connected to the second micro water bag 2423, a fixed layer 2424-2 and multiple micro water seepage channels 2424-3; a uniform water film is formed by the micro water seepage channel and the thin cloth layer to avoid the streams of water that may be formed by traditional water coupling affecting the array eddy current detection below the ultrasonic detection.

[0077] The fixed layer 2424-2 is evenly distributed with through holes corresponding to the plurality of micro water seepage channels 2424-3;

[0078] The thin cloth layer 2425 is fixedly arranged on the detection surface of the array ultrasonic surface wave detection sensor 241;

[0079] The micro water seepage structure 2424 is integrated above the array ultrasonic surface wave detection sensor 241 , and the water outlets of the multiple micro water seepage channels 2424 - 3 are connected to the thin cloth layer 2425 .

[0080] Furthermore, the contoured array eddy current detection sensor 231 includes:

[0081] The contoured coil bobbin 2311 is adapted to fit the concave curvature of the surface to be inspected and matches the R angle of the tenon root;

[0082] The coil array 2312 is configured as an eight-channel coil array or a sixteen-channel coil array and is embedded in the contoured coil frame 2311 ;

[0083] The micro-spring pressure structure, located on the back of the contoured coil bobbin 2311, comprises a matrix of coil springs and a second elastic conductive layer covering the spring array. The multi-channel coil completely covers the test area and, combined with the micro-spring pressure structure, dynamically compensates for minor surface irregularities, improving detection sensitivity.

[0084] Furthermore, the plurality of micro water seepage channels 2424-3 are evenly distributed on the four sides of the housing of the array ultrasonic surface wave detection sensor 241, forming a three-dimensional transmission channel so that the coupling agent (water) can evenly cover the thin cloth layer.

[0085] An in-service in-situ electromagnetic acoustic detection method for aircraft engine blades, using the above-mentioned detection system, includes the following steps:

[0086] S1. Probe positioning and coupling:

[0087] The contoured array eddy current detection sensor 231 is placed on the R-angle surface of the root of the blade tenon by moving the probe portion 220, and the detection surface is automatically pressed against the R-angle surface of the root of the blade tenon by the three-point positioning structure 232;

[0088] In this embodiment, the three-point positioning structure features a micro-spring-type pressure structure on the back of each of the three pressure rods, achieving elastic conformal performance. In other embodiments, the three-point positioning structure can be made of shape memory alloy, dynamically adjusting the contact pressure based on the blade's R-angle curvature during testing. The coil array utilizes a flexible PCB coil array embedded in a contoured coil bobbin.

[0089] Rotate the universal hinge structure 250 to adjust the angle of the array ultrasonic surface wave detection module 240 so that the array ultrasonic surface wave detection sensor 241 is in contact with the blade surface above the root of the blade tenon;

[0090] Pressing the first micro water bag 2421 causes water to flow through the micro water channel 2422 to the second micro water bag 2423 , and then penetrate the thin fabric layer 2425 through the micro water permeable structure 2424 to form an ultrasonically coupled water film.

[0091] In this embodiment, manual adjustment is adopted. In other embodiments, a piezoelectric micro pump can be integrated on the first micro water bag structure to adjust the water flow rate as needed to ensure the stability of the water film thickness.

[0092] S2. Synchronous scanning and detection

[0093] S2.1 Array Eddy Current Testing

[0094] The drive coil array 2312 emits a multi-frequency excitation signal, moves and scans along the R-angle surface of the blade tenon root, and collects eddy current detection signals of cracks on the blade tenon root surface in real time;

[0095] S2.2 Array Ultrasonic Surface Wave Detection

[0096] The array ultrasonic surface wave detection sensor 241 transmits a directional surface wave beam, moves and scans along the blade surface above the root of the blade tenon, and receives the ultrasonic detection signal of the internal crack of the blade tenon root in real time;

[0097] The array eddy current testing and array ultrasonic surface wave testing are performed simultaneously on the same scanning path. The array eddy current testing module 230 collects multi-channel eddy current testing signals in real time, while the array ultrasonic surface wave testing module 240 transmits a directional surface wave beam and receives echo signals. The electromagnetic and acoustic integrated testing instrument 100 processes both signals synchronously. The eddy current testing signal uses phase analysis to identify surface cracks, while the ultrasonic testing signal uses amplitude attenuation analysis to determine internal defects.

[0098] S3. Collaborative Crack Identification

[0099] S3.1 Surface crack determination

[0100] Extract the phase mutation points and amplitude abnormal areas of the eddy current detection signal and mark them as the surface crack locations;

[0101] S3.2 Internal crack determination

[0102] In the scanned area with no abnormalities during eddy current testing, the attenuation information of the ultrasonic testing signal is extracted. If there is no obvious abnormality in the ultrasonic testing signal in the same area, but the amplitude attenuation detected in the adjacent area exceeds the preset threshold, it is marked as the internal crack location when it exceeds the preset threshold.

[0103] S3.3 Comprehensive Positioning

[0104] Through the crack collaborative identification algorithm of the electromagnetic and acoustic integrated detector 100, the surface crack position and the internal crack position are mapped to the same spatial coordinate system, and a three-dimensional crack distribution map is output to intuitively display the defect location, size and depth information. Risk level assessment is performed based on the crack distribution map. In one embodiment, eddy current detection found multiple phase abnormalities at the root of the blade tenon, which were confirmed to be a surface thermal fatigue crack network after analysis. At the same time, ultrasonic detection detected amplitude attenuation abnormalities in the area near the surface crack, which was determined to be an internal buried crack, and there was a trend of connectivity with the surface crack. Through the crack collaborative identification algorithm, a three-dimensional crack distribution map is generated, and the crack extension trend is predicted and analyzed to provide data support for the remaining life assessment of the blade.

[0105] The present invention uses eddy current and ultrasonic complementarity to conduct electromagnetic and acoustic collaborative detection, achieving full coverage of surface and internal defects of the blade tenon, and designs an adaptive coupling structure to effectively solve the problem of complex surface coupling, providing a comprehensive basis for maintenance decisions of turbine blades.

[0106] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. An in-service electromagnetic acoustic detection system for aircraft engine blades, characterized by: include: An electromagnetic acoustic integrated detector (100) comprising an array eddy current detection function and an ultrasonic surface wave detection function; An electromagnetic acoustic detection probe (200) is designed as a contoured array eddy current-array ultrasonic surface wave integrated probe; The electromagnetic acoustic detection probe (200) comprises a handle portion (210), a probe portion (220), a contoured array eddy current detection module (230), an array ultrasonic surface wave detection module (240), and a universal hinge structure (250); The probe portion (220) is designed as a hollow cavity, one end of which is fixedly connected to the handle portion (210), and the other end of which is rotatably connected to the contour array eddy current detection module (230) via a universal hinge structure (250); The contour array eddy current detection module (230) comprises a contour array eddy current detection sensor (231) and a three-point positioning structure (232), which is used to fit the R-angle surface of the root of the blade tenon; The three-point positioning structure (232) comprises a first pressing rod (2321), a second pressing rod (2322), a third pressing rod (2323) and a first elastic conductive layer (2324) connecting and fixing the three pressing rods, which are evenly spaced and arranged on the back of the contoured array eddy current detection sensor (231); The array ultrasonic surface wave detection module (240) comprises an array ultrasonic surface wave detection sensor (241) and a coupling water delivery device (242), and is used to fit the blade surface above the root of the blade tenon; The coupled water transfer device (242) includes a first micro water bag (2421), a micro water transfer channel (2422), a second micro water bag (2423), a micro water permeable structure (2424), and a thin fabric layer (2425); The first micro water bag (2421) is fixedly arranged on one side of the handle portion (210) via a first connecting end (2421-1) and a second connecting end (2421-2); The micro water delivery channel (2422) is arranged in the cavity of the probe portion (220), one end of which is connected to the first micro water bag (2421) through the first through hole (2201) on the probe portion (220), and the other end is connected to the second micro water bag (2423) also arranged in the cavity of the probe portion (220); The micro water seepage structure (2424) comprises: a micro water storage channel (2424-1) communicating with the second micro water bag (2423), a fixed layer (2424-2), and a plurality of micro water seepage channels (2424-3); The fixed layer (2424-2) is evenly distributed with through holes corresponding one to one to the plurality of micro water seepage channels (2424-3); The thin cloth layer (2425) is fixedly arranged on the detection surface of the array ultrasonic surface wave detection sensor (241); The micro water seepage structure (2424) is integrated above the array ultrasonic surface wave detection sensor (241), and the water outlets of the multiple micro water seepage channels (2424-3) are connected to the thin cloth layer (2425).

2. The in-service in-situ electromagnetic acoustic detection system for aircraft engine blades according to claim 1, characterized in that: The contoured array eddy current detection sensor (231) comprises: A contoured coil frame (2311) adapted to fit the concave curvature of the surface to be inspected and matching the R angle of the root of the tenon; The coil array (2312) is configured as an eight-channel coil array or a sixteen-channel coil array and is embedded in the contoured coil frame (2311); The micro spring pressing structure is arranged on the back of the contoured coil frame (2311), and includes spiral springs arranged in a matrix and a second elastic conductive layer covering the spring array.

3. The in-service in-situ electromagnetic acoustic detection system for aircraft engine blades according to claim 1, characterized in that: The plurality of micro water seepage channels (2424-3) are evenly distributed on the four sides of the inner shell of the array ultrasonic surface wave detection sensor (241).

4. A method for in-service electromagnetic acoustic detection of aircraft engine blades, using the detection system according to any one of claims 1 to 3, characterized in that: The following steps are involved: S1. Probe positioning and coupling: The contoured array eddy current detection sensor (231) is placed on the R-angle surface of the root of the blade tenon by moving the probe portion (220), and the detection surface is automatically pressed against the R-angle surface of the root of the blade tenon by a three-point positioning structure (232); Rotating the universal hinge structure (250) to adjust the angle of the array ultrasonic surface wave detection module (240) so that the array ultrasonic surface wave detection sensor (241) fits the blade surface above the root of the blade tenon; Pressing the first micro water bag (2421), water flows through the micro water channel (2422) to the second micro water bag (2423), and penetrates the thin cloth layer (2425) through the micro water permeable structure (2424) to form an ultrasonically coupled water film; S2. Synchronous scanning and detection S2.1 Array Eddy Current Testing The driving coil array (2312) emits a multi-frequency excitation signal, moves and scans along the R-angle surface of the blade tenon root, and collects eddy current detection signals of cracks on the blade tenon root surface in real time; S2.2 Array Ultrasonic Surface Wave Detection An array ultrasonic surface wave detection sensor (241) is used to emit a directional surface wave beam, which is moved and scanned along the blade surface above the blade tenon root, and an ultrasonic detection signal of cracks inside the blade tenon root is received in real time; The array eddy current detection and the array ultrasonic surface wave detection are performed synchronously on the same scanning path. S3. Collaborative Crack Identification S3.1 Surface crack determination Extract the phase mutation points and amplitude abnormal areas of the eddy current detection signal and mark them as the surface crack locations; S3.2 Internal crack determination In the scanned area with no abnormalities during eddy current testing, the attenuation information of the ultrasonic testing signal is extracted. When it exceeds the preset threshold, it is marked as the internal crack location; S3.3 Comprehensive Positioning The surface crack positions and internal crack positions are mapped to the same spatial coordinate system, and a crack distribution map is output.

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