Metal material performance detection sensor, system and method

Abstract

The invention discloses a metal material performance detection sensor, system and method. The detection system comprises a laser and a metal material performance detection sensor. The metal material performance detection sensor comprises an electromagnetic ultrasonic transducer EMAT and a magnetism gathering ring. When in use, the EMAT and the magnetism gathering ring are respectively arranged on two sides of a metal material sample; laser emitted by the laser device penetrates through the magnetism gathering ring to generate an ultrasonic signal in the metal material sample, and the ultrasonic signal is finally received by the EMAT. And calculating a metal material performance detection result based on the signals acquired by the EMAT. According to the invention, non-contact detection is adopted, and the signal-to-noise ratio is high.

Description

Technical Field

[0001] The present application relates to the field of metal material performance detection, and specifically to a metal material performance detection sensor, system and method. Background Art

[0002] my country's aerospace technology has advanced by leaps and bounds, and high-end equipment such as the J-20 and C919 have emerged. With the design and development of more high-end weapons and equipment, aerospace hot-end components are constantly developing towards high performance, high reliability and high safety, and working conditions are becoming more and more harsh and complex. Therefore, the mechanical properties testing of new materials (high temperature, vibration, corrosion) in extreme environments has gradually gained the attention of material researchers. Due to the lack of high-temperature resistant non-destructive testing technology, researchers are unable to obtain the performance degradation mechanism and failure model of metal materials in ultra-high temperature environments, and lack experimental data to guide the development and preparation of high-temperature alloy materials with high service performance in ultra-high temperature environments. Therefore, the development of a new high-temperature acoustic non-destructive testing technology has great engineering application value.

[0003] At present, the methods used in high temperature non-destructive testing technology at home and abroad are:

[0004] (1) Contact piezoelectric ultrasonic testing technology: Piezoelectric ultrasonic transducers are now capable of high-temperature testing due to the widespread application of high-temperature piezoelectric materials, but contact measurement still has the problem of difficulty in movement.

[0005] (2) Non-contact air-coupled ultrasonic detection technology. However, due to the serious mismatch in acoustic impedance between the air medium and the ultrasonic transducer material, the received ultrasonic signal will have a low amplitude and a poor signal-to-noise ratio.

[0006] (3) Non-contact laser ultrasonic detection technology. However, laser ultrasonic detection technology has high requirements on the surface roughness of the object in the receiving part of the interferometer, is costly, and is not conducive to detection in harsh environments.

[0007] (4) Non-contact electromagnetic ultrasonic detection technology. At present, electromagnetic acoustic resonance detection technology is relatively mature and can realize corrosion thinning detection in harsh environments, but it needs to complete frequency scanning work, and the electromagnetic ultrasonic detection receiving signal has the problem of low signal-to-noise ratio.

[0008] (5) The non-contact laser-electromagnetic ultrasonic detection technology combines laser ultrasound with electromagnetic ultrasound. It fully combines the advantages of both laser ultrasonic detection and electromagnetic ultrasonic detection. It not only utilizes the advantages of laser ultrasonic excitation broadband, but also utilizes the advantages of electromagnetic ultrasonic detection technology that has low surface requirements and low cost. However, the use of electromagnetic ultrasonic detection still has the problem of low signal-to-noise ratio when receiving signals.

[0009] Existing technologies are unable to achieve good online detection results for aerospace hot end components in extreme environments, such as aerospace engine turbine blades, tail nozzles, etc. Summary of the invention

[0010] The purpose of this application is to provide a metal material property detection sensor, system and method, which adopts non-contact detection and has a high signal-to-noise ratio.

[0011] In a first aspect, the present application provides a metal material performance detection sensor, including an electromagnetic ultrasonic transducer EMAT and a magnetic focusing ring;

[0012] When in use, the EMAT and the magnetic focusing ring are respectively placed on both sides of the metal material sample; the laser emitted by the laser passes through the magnetic focusing ring to generate an ultrasonic signal in the metal material sample and is finally received by the EMAT.

[0013] In some possible implementations, the EMAT includes a stepped permanent magnet and a coil;

[0014] The step permanent magnet comprises a first permanent magnet and a second permanent magnet which are coaxially arranged; the first permanent magnet and the second permanent magnet are both cylindrical, the first permanent magnet is arranged on the second permanent magnet, and the diameter of the first permanent magnet is smaller than the diameter of the second permanent magnet;

[0015] The coil is arranged at the front end of the first permanent magnet.

[0016] In some possible implementations, the permanent magnets of the EMAT and the magnetic focusing ring are both SmCo permanent magnets that can withstand a high temperature of 350°C.

[0017] In some possible implementations, the coil is a high-temperature resistant ceramic silver coil; the stepped permanent magnet and the coil are assembled in a shell with an opening at the front end, and the space between the shell and the stepped permanent magnet and the coil is filled with high-temperature resistant ceramic gel; a mica sheet is provided between the coil and the front end of the shell.

[0018] In some possible implementations, the magnetic focusing ring is in the shape of a circular column, and is evenly divided into two parts, an upper part and an lower part, along the axial direction, wherein the upper part is magnetized to an N pole, and the lower part is magnetized to an S pole.

[0019] In some possible implementations, the magnetic focusing ring includes a third permanent magnet, a fourth permanent magnet and a fifth permanent magnet;

[0020] The third permanent magnet is in the shape of a circular column with equal inner diameters at the top and bottom;

[0021] The fourth permanent magnet is in the shape of a circular column with a large inner diameter at the upper part and a small inner diameter at the lower part;

[0022] The fifth permanent magnet is in the shape of a circular column with equal inner diameters at the top and bottom;

[0023] The third permanent magnet, the fourth permanent magnet and the fifth permanent magnet are coaxially arranged;

[0024] The height of the third permanent magnet is equal to that of the fourth permanent magnet, and the bottom surfaces are on the same plane; the third permanent magnet is sleeved outside the fourth permanent magnet;

[0025] The fifth permanent magnet is arranged on the lower part of the fourth permanent magnet; the outer diameter of the fifth permanent magnet is equal to the inner diameter of the upper part of the fourth permanent magnet; the inner diameter of the fifth permanent magnet is equal to the inner diameter of the lower part of the fourth permanent magnet; the height of the fifth permanent magnet is less than the height of the upper part of the fourth permanent magnet.

[0026] The longitudinal section of the magnetic focusing ring is divided into two symmetrical parts; the third permanent magnet, the fourth permanent magnet and the fifth permanent magnet in the left part are magnetized to S pole, N pole and S pole respectively, and the third permanent magnet, the fourth permanent magnet and the fifth permanent magnet in the right part are magnetized to N pole, S pole and N pole respectively.

[0027] In some possible implementations, the magnetic concentrator ring includes a sixth permanent magnet, a seventh permanent magnet, and a soft magnetic concentrator;

[0028] The sixth permanent magnet, the seventh permanent magnet and the soft magnetic concentrator are all in the shape of a circular column;

[0029] The sixth permanent magnet, the seventh permanent magnet and the soft magnetic concentrator are coaxially arranged;

[0030] The sixth permanent magnet is magnetized along the axial direction and is divided into two parts, the upper part is magnetized to an N pole, and the lower part is magnetized to an S pole;

[0031] The sixth permanent magnet is placed on the soft magnetic concentrator;

[0032] The seventh permanent magnet and the soft magnetic concentrator are of equal height, and their bottom surfaces are on the same plane; the seventh permanent magnet is sleeved outside the soft magnetic concentrator;

[0033] The inner diameter of the soft magnetic concentrator is equal to the inner diameter of the sixth permanent magnet; the seventh permanent magnet is magnetized radially and is divided into an inner part and an outer part; the outer diameter of the soft magnetic concentrator is equal to the inner diameter of the seventh permanent magnet and is smaller than the outer diameter of the sixth permanent magnet; the outer diameter of the inner part of the seventh permanent magnet is larger than the outer diameter of the sixth permanent magnet.

[0034] The outer portion of the seventh permanent magnet is magnetized to an N pole, and the inner portion of the seventh permanent magnet is magnetized to an S pole.

[0035] In a second aspect, the present application provides a metal material property detection system, comprising a laser and the above-mentioned metal material property detection sensor;

[0036] The laser is used as the excitation part, and the metal material performance detection sensor is used as the receiving part;

[0037] When in use, the laser emitted by the laser passes through the magnetic focusing ring to generate an ultrasonic signal in the metal material sample and is finally received by the EMAT; the metal material performance test result is calculated based on the signal collected by the EMAT.

[0038] In some possible implementations, the laser is provided with a multi-joint rotating shaft mechanical light-guiding arm; the laser light emitted by the laser is guided to the to-be-tested area of ​​the metal material sample through the multi-joint rotating shaft mechanical light-guiding arm, thereby exciting ultrasonic waves;

[0039] The system also includes an eddy current heater for heating the metal material sample;

[0040] The system also includes a three-dimensional vibration platform for placing metal material samples and simulating vibration environment.

[0041] In some possible implementations, the system further includes an XZ-axis two-dimensional scanning platform for installing the EMAT to achieve two-dimensional scanning of metal material samples.

[0042] In some possible implementations, the system further includes an impedance matcher, a preamplifier, a data acquisition card, and a computer connected in sequence; the impedance matcher is connected to the EMAT; the impedance matcher is used to adjust the matching capacitance and inductance parameters of the EMAT coil so that the amplitude and signal-to-noise ratio of the received signal are maximized while increasing the frequency bandwidth of the resonance signal; then the resonance signal passes through the preamplifier and the data acquisition card, and the data acquisition card transmits the signal to the computer, thereby obtaining the required resonance spectrum signal.

[0043] In a third aspect, the present application provides a metal material performance detection method, based on the above-mentioned metal material performance detection system, collecting resonance spectrum signals, and calculating the thickness d of the metal material sample based on the resonance spectrum signals:

[0044]

[0045] Where c is the ultrasonic speed, f is m 、f n are the frequency magnitudes of the mth resonant frequency point and the nth resonant frequency point respectively, m>n≥1.

[0046] Beneficial effects:

[0047] This application is based on the laser-electromagnetic ultrasonic detection technology of the resonance method. The laser is used to excite the ultrasonic signal. The metal material performance detection sensor receives the ultrasonic echo signal. The electromagnetic ultrasonic receiving performance is optimized and improved by the magnetic focusing ring. It can achieve non-contact detection with a large lift of 15mm, and the detection signal is not affected by the vibration environment. The resonance technology is integrated to greatly increase the amplitude of the detection signal and improve the signal-to-noise ratio of the detection signal. Under the working conditions of large lift-off, this application uses a high-temperature resistant SmCo permanent magnet, and after high-temperature design treatment of the metal material performance detection sensor, it can also achieve ultra-high temperature continuous online monitoring. This application can obtain high-reliability and high-quality detection data in a high-temperature vibration environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the technical solution of the embodiment of the present application, the following is a brief introduction to the drawings required for use in the embodiment. It should be understood that the following drawings Figure 1 To Attachment Figure 8 Only certain embodiments of the present application are shown, and therefore should not be regarded as limiting the scope of protection of the present application. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying any creative work.

[0049] Figure 1 This is a schematic diagram of the use of a metal material property sensor in an embodiment of the present application;

[0050] Figure 2 This is a schematic diagram of an EMAT structure in an embodiment of the present application;

[0051] Figure 3 This is a magnetic focusing ring structure in the embodiment of the present application, wherein Figure 3 (a) is the longitudinal section. Figure 3 (b) is a top view;

[0052] Figure 4 This is a magnetic focusing ring structure in the embodiment of the present application, wherein Figure 4 (a) is the longitudinal section. Figure 4 (b) is a top view;

[0053] Figure 5 This is a magnetic focusing ring structure in the embodiment of the present application, wherein Figure 5 (a) is the longitudinal section. Figure 5 (b) is a top view;

[0054] Figure 6 This is a schematic diagram of the structure of a metal material performance detection system in an embodiment of the present application;

[0055] Figure 7 Schematic diagram of the resonance signal and the resonance spectrum signal in the embodiment of the present application, wherein Figure 7(a) is a schematic diagram of the resonance signal obtained under the optimal parameter combination and the worst parameter combination; Figure 7 (b) Schematic diagram of resonance spectrum signal;

[0056] Figure 8 Schematic diagram of ultrasonic excitation under thermoelastic mechanism. DETAILED DESCRIPTION

[0057] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

[0058] It should be noted that the terms such as "first", "second" and the like in the specification and claims of the present application and the above-mentioned drawings are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is a specific relationship or order between these entities or operations. It should be understood that the words "first", "second" and the like do not limit the quantity and execution order, and the words "first" and "second" and the like do not limit them to be necessarily different. It should be understood that the data used in this way can be interchanged under appropriate circumstances. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, so that the process, method, article or device including a series of elements includes not only those elements clearly listed, but also other elements that are not clearly listed, or may also include elements inherent to such process, method, product or device. In the absence of more restrictions, the elements defined by the sentence "including one..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0059] In the present application, the terms "upper", "lower", "left", "right", "front", "back", "top", "bottom", "inner", "outer", "middle", "vertical", "horizontal", "lateral", "longitudinal" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings. These terms are mainly used to better describe the present application and its embodiments, and are not used to limit the indicated devices, elements or components to have a specific orientation, or to be constructed and operated in a specific orientation.

[0060] In addition, some of the above terms may be used to express other meanings in addition to indicating orientation or positional relationship. For example, the term "on" may also be used to express a certain dependency or connection relationship in some cases. For those of ordinary skill in the art, the specific meanings of these terms in this application can be understood according to specific circumstances.

[0061] In addition, the terms "installed", "set", "provided with", "connected", "connected", and "socketed" should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, elements, or components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0062] In order to solve the problem of lack of online testing technology for corrosion and thinning of aircraft engine turbine blades and tail nozzles under high temperature and vibration environment, this application proposes a metal material performance detection sensor, system and method. The laser electromagnetic ultrasonic detection technology based on the resonance method has the advantages of non-contact, high signal-to-noise ratio, high temperature resistance, wide frequency band, etc. It is suitable for non-destructive testing in harsh environments such as high temperature and vibration, and can realize damage vibration testing of metal material samples (workpieces to be tested) within 10mm thickness.

[0063] Specific embodiments according to the present application will be described below with reference to the accompanying drawings.

[0064] like Figure 1 As shown, an embodiment of the present application provides a metal material property sensor, including an electromagnetic ultrasonic transducer EMAT (English: ElectromagneticAcoustic Transducer) and a magnetic focusing ring;

[0065] When in use, the EMAT and the magnetic focusing ring are respectively placed on both sides of the metal material sample; the laser emitted by the laser passes through the magnetic focusing ring to generate an ultrasonic signal in the metal material sample and is finally received by the EMAT.

[0066] The embodiment of the present application proposes an electromagnetic ultrasonic sensor configuration that uses a magnetic field focusing ring to focus magnetic field. It can greatly improve the bias magnetic field required for electromagnetic ultrasonic receiving signals without hindering the normal laser light path, significantly improve the conversion efficiency of the electromagnetic ultrasonic transducer, and can greatly improve the bias magnetic field strength and the detection signal amplitude. By using the relationship that the EMAT signal-to-noise ratio is proportional to the square of the magnetic flux density, the signal-to-noise ratio of the detection signal can be further improved, thereby achieving large lift-off detection. The signal-to-noise ratio of the detection signal can be significantly improved by combining with the resonant thickness measurement technology, so that large lift-off corrosion thinning detection of 15mm can be achieved. It is suitable for online testing of thermal corrosion thinning and damage stress under high temperature, vibration, and large lift-off scenarios.

[0067] In some embodiments, Figure 2 As shown, the EMAT includes a stepped permanent magnet and a coil;

[0068] The step permanent magnet comprises a first permanent magnet and a second permanent magnet which are coaxially arranged; the first permanent magnet and the second permanent magnet are both cylindrical, the first permanent magnet is arranged on the second permanent magnet, and the diameter of the first permanent magnet is smaller than the diameter of the second permanent magnet;

[0069] The coil is arranged at the front end of the first permanent magnet.

[0070] In some embodiments, the permanent magnets of the EMAT and the magnetic focusing ring are both SmCo permanent magnets that can withstand high temperatures of 350° C., further increasing the high temperature resistance of the electromagnetic ultrasonic sensor.

[0071] In some embodiments, the coil is a new type of high temperature resistant ceramic silver coil, for example, a ceramic silver coil resistant to high temperatures of 850°C.

[0072] In some embodiments, the step permanent magnet and the coil are assembled in a housing with an opening at the front end, and a high temperature resistant ceramic gel is filled between the housing, the step permanent magnet and the coil. For example, the ceramic gel can withstand a high temperature of 1000°C for an instant. A mica sheet is arranged between the coil and the front end of the housing.

[0073] By isolating the coil with high-temperature mica sheets, the impact of temperature on the sensor can be further reduced in a large lift-off environment, enabling ultra-high temperature continuous detection.

[0074] The present application discloses a receiving probe in the form of a stepped permanent magnet with a ring magnet, a high temperature resistant ceramic silver coil, a high temperature resistant SmCo permanent magnet, and a high temperature resistant ceramic gel for infusion, which can greatly improve the residual magnetic induction intensity of the permanent magnet under high temperature conditions, and can achieve a 15mm large lift-off detection application under high temperature flutter conditions. And a high temperature resistant mica sheet is used for further isolation, which not only plays an insulating role, but also has the characteristics of wear resistance, high temperature resistance, and corrosion resistance, which can further protect the detection line, so that the sensor has good high temperature resistance and corrosion resistance under large lift-off conditions, and can achieve high temperature resistance and continuous detection above 1000°C.

[0075] like Figure 3 , Figure 4 as well as Figure 5 (Longitudinal section and top view) show three different configurations of magnetic ring structures.

[0076] In some embodiments, Figure 3 As shown, the magnetic focusing ring is in the shape of a circular column, and is evenly divided into two parts along the axial direction, the upper half is magnetized to the N pole, and the lower half is magnetized to the S pole.

[0077] The use of the magnetic focusing ring structure to focus magnetic field can not only allow the light source to pass normally and thus generate ultrasonic waves on the surface of the metal material sample, but also further enhance the bias magnetic field strength.

[0078] In some embodiments, Figure 4 As shown, the magnetic focusing ring includes a third permanent magnet, a fourth permanent magnet and a fifth permanent magnet;

[0079] The third permanent magnet is in the shape of a circular column with equal inner diameters at the top and bottom;

[0080] The fourth permanent magnet is in the shape of a circular column with a large inner diameter at the upper part and a small inner diameter at the lower part;

[0081] The fifth permanent magnet is in the shape of a circular column with equal inner diameters at the top and bottom;

[0082] The third permanent magnet, the fourth permanent magnet and the fifth permanent magnet are coaxially arranged;

[0083] The height of the third permanent magnet is equal to that of the fourth permanent magnet, and the bottom surfaces are on the same plane; the third permanent magnet is sleeved outside the fourth permanent magnet;

[0084] The fifth permanent magnet is arranged on the lower part of the fourth permanent magnet; the outer diameter of the fifth permanent magnet is equal to the inner diameter of the upper part of the fourth permanent magnet; the inner diameter of the fifth permanent magnet is equal to the inner diameter of the lower part of the fourth permanent magnet; the height of the fifth permanent magnet is less than the height of the upper part of the fourth permanent magnet.

[0085] The longitudinal section of the magnetic focusing ring is divided into two symmetrical parts; the third permanent magnet, the fourth permanent magnet and the fifth permanent magnet in the left part are magnetized to S pole, N pole and S pole respectively, and the third permanent magnet, the fourth permanent magnet and the fifth permanent magnet in the right part are magnetized to N pole, S pole and N pole respectively.

[0086] Figure 4 For Figure 3 A new improved magnet configuration form (Improved Type 1) is proposed based on the magnetic focusing ring structure shown in the figure. This structure is improved based on the principle of the Halbach array and is based on the actual application scenario. Using the principle of the Halbach array, a permanent magnet with a circular cross section is surrounded by a permanent magnet with a circular cross section magnetized in the horizontal direction. With this configuration, the vertical magnetic field below the magnetic focusing ring is significantly enhanced.

[0087] In some embodiments, the magnetic concentrator ring includes a sixth permanent magnet, a seventh permanent magnet, and a soft magnetic concentrator;

[0088] The sixth permanent magnet, the seventh permanent magnet and the soft magnetic concentrator are all in the shape of a circular column;

[0089] The sixth permanent magnet, the seventh permanent magnet and the soft magnetic concentrator are coaxially arranged;

[0090] The sixth permanent magnet is magnetized along the axial direction and is divided into two parts, the upper part is magnetized to an N pole, and the lower part is magnetized to an S pole;

[0091] The sixth permanent magnet is placed on the soft magnetic concentrator;

[0092] The seventh permanent magnet and the soft magnetic concentrator are of equal height, and their bottom surfaces are on the same plane; the seventh permanent magnet is sleeved outside the soft magnetic concentrator;

[0093] The inner diameter of the soft magnetic concentrator is equal to the inner diameter of the sixth permanent magnet; the seventh permanent magnet is magnetized radially and is divided into an inner part and an outer part; the outer diameter of the soft magnetic concentrator is equal to the inner diameter of the seventh permanent magnet and is smaller than the outer diameter of the sixth permanent magnet; the outer diameter of the inner part of the seventh permanent magnet is larger than the outer diameter of the sixth permanent magnet.

[0094] The outer portion of the seventh permanent magnet is magnetized to an N pole, and the inner portion of the seventh permanent magnet is magnetized to an S pole.

[0095] Figure 5 For Figure 3Another new type of magnet configuration structure (improved type 2) proposed on the basis of the magnetic focusing ring structure shown in the figure can generate a vertical magnetic field inside the magnetic focusing ring, and the polarity of the magnetic field is opposite to the axial magnetic field provided by the step permanent magnet, thereby playing a role in magnetic focusing. The circular cylindrical magnet and the soft magnetic concentrator are used to make all adjacent magnetic poles have the same polarity, thereby achieving the purpose of magnetic focusing.

[0096] The three types of magnetic concentrating magnets proposed in the embodiments of the present application are all simulated and modeled using the finite element simulation software COMSOL, and all have a significant improvement in the bias magnetic field required for detection.

[0097] In a fourth aspect, an embodiment of the present application further provides a metal material property detection system, comprising a laser and the above-mentioned metal material property detection sensor;

[0098] The laser is used as the excitation part, and the metal material performance detection sensor is used as the receiving part;

[0099] When in use, the laser emitted by the laser passes through the magnetic focusing ring to generate an ultrasonic signal in the metal material sample, which is finally received by the EMAT; the metal material performance test result is calculated based on the signal collected by the EMAT.

[0100] In some embodiments, the laser is a Nimma series Q-switched Nd:YAG 1064nm solid pulse laser developed by ematech.

[0101] In some embodiments, the laser spot diameter emitted by the laser is 8 mm, the laser pulse width is 8 ns, and the repetition frequency is 10 Hz.

[0102] In some embodiments, the single pulse energy of the laser beam used is 185 mJ corresponding to 600 V, which does not reach the ablation threshold and does not damage the surface of the metal material sample.

[0103] In some embodiments, the laser uses liquid cooling circulation to dissipate heat and can emit laser light with a wavelength of 1064 nm.

[0104] like Figure 6 As shown, in some embodiments, the laser is provided with a multi-joint rotating shaft mechanical light guide arm, which can realize three-dimensional light path deflection, improve the detection efficiency in complex environments, and also facilitate the realization of scanning functions. The laser emitted by the laser is guided to the area to be tested of the metal material sample through the multi-joint rotating shaft mechanical light guide arm, thereby exciting ultrasonic waves.

[0105] In some embodiments, the multi-joint rotating shaft mechanical light-guiding arm contains a beam splitter inside, which, together with the voltage control of the laser (545V~700V) and a 10-speed attenuator, can achieve stable and adjustable single pulse energy of the laser beam in the range of 0.5mJ~600mJ, which can meet the detection requirements.

[0106] In some embodiments, the system further comprises an eddy current heater for heating the metal material sample.

[0107] The metal material sample is heated by an eddy current heater and wrapped with thermal insulation cotton, which can achieve a heating function of more than 1000°C.

[0108] In some embodiments, the system further comprises a three-dimensional vibration platform for placing the metal material sample and simulating a vibration environment.

[0109] Based on the eddy current heater and the three-dimensional vibration platform, it is possible to simulate the complex working environment of high temperature vibration of aircraft engine turbine blades and tail nozzles, so as to conduct online acoustic detection of the performance of metal materials such as aircraft engine turbine blades and tail nozzle corrosion and thinning under high temperature vibration environment, and provide experimental data to guide the development and preparation of high-temperature alloy materials with high service performance in ultra-high temperature environment.

[0110] In some embodiments, the system further comprises an XZ-axis two-dimensional scanning platform for installing the EMAT to achieve two-dimensional scanning of metal material samples.

[0111] In some embodiments, the XZ-axis two-dimensional scanning platform is configured with a human-computer interaction interface.

[0112] EMAT performs scanning via an XZ-axis two-dimensional scanning platform, and uses a human-computer interaction interface developed based on Labview to achieve automated scanning and data collection of planned paths.

[0113] In some embodiments, the system further includes an impedance matcher, a preamplifier, a data acquisition card, and a computer connected in sequence; the impedance matcher is connected to the EMAT; the impedance matcher is used to adjust the matching capacitance and inductance parameters of the EMAT coil, improve the amplitude and signal-to-noise ratio of the received resonance signal, and at the same time improve the bandwidth of the resonance signal to obtain a resonance signal with a high-frequency bandwidth of the signal-to-noise ratio. After the resonance signal is amplified by the preamplifier, the resonance signal is transmitted to the computer by the data acquisition card, and the resonance signal is Fourier transformed in the computer, from a time domain signal to a frequency domain signal, so as to obtain the required resonance spectrum signal.

[0114] Among them, the impedance matcher adopts LC impedance matcher, including multiple inductors and capacitors. The LC impedance matcher is essentially a low-pass filter. There are many inductors such as 40μH, 25μH, 20μH, 6.3μH, 5.6μH, etc. on the impedance matcher. Generally, only one inductor is selected, and the influence of each inductor on the signal can be tested separately to select the inductor with the best signal. Each capacitor is connected in parallel, the largest is 10nF and the smallest is 100pF. The capacitance value of the capacitor in parallel is the sum of the capacitance values ​​of the single capacitors in parallel. For example, the total capacitance value of the circuit of 10nF and 10nF in parallel becomes 20nF. The experiment is carried out by gradually increasing the capacitance from small to large, and the capacitance combination parameters with the best signal effect are selected. In addition, it has been found that the signal bandwidth will decrease when the capacitance value is large, and the amplitude of the low-frequency signal will increase. The signal bandwidth will be wider when the capacitance value is small, and the amplitude of the high-frequency signal will increase, but the amplitude of the signal with the largest amplitude is not as good as when the capacitance value is large. Since the signal-to-noise ratio is the signal divided by the noise, the signal-to-noise ratio will increase when the signal amplitude is large. Therefore, it is necessary to select the optimal parameter combination according to the bandwidth and amplitude requirements of the selected signal, that is, the optimal impedance matching parameter combination, so as to improve the amplitude and signal-to-noise ratio of the received resonant signal, and at the same time increase the bandwidth of the resonant signal to obtain a resonant signal with a high-frequency bandwidth and a high signal-to-noise ratio.

[0115] like Figure 7 As shown, Figure 7 (a) is a schematic diagram of the resonant A-scan signal obtained under a lift-off of 0.5 mm; Figure 7 (b) is a schematic diagram of the resonant spectrum signal of EMAT at a lift-off of 0.5 mm.

[0116] In some embodiments, the preamplifier is an OLYMPUS 5072PR preamplifier.

[0117] The embodiment of the present application also provides a method for detecting the properties of metal materials. The method can use the laser electromagnetic ultrasonic resonance method to perform performance detection and safety assessment of aviation materials constituting hot end components.

[0118] The mechanism of laser-induced ultrasound is based on the power density of the incident light (10 6 W / cm 2 ) is divided into thermoelastic mechanism and ablation mechanism. Under the thermoelastic mechanism, the laser will not damage the surface of the material. At the same time, the shear wave has a greater amplitude than the longitudinal wave for thin metal material samples. Therefore, the excitation part adopts the principle of exciting ultrasonic waves under the thermoelastic mechanism. Figure 8 This is the principle diagram of ultrasonic excitation under the thermoelastic mechanism. When the laser energy density is less than the damage threshold of the solid surface, the irradiated area of ​​the solid illuminated by the light beam absorbs the laser energy and converts it into thermal energy. The local material within the spot range quickly heats up, resulting in local rapid thermal expansion, thereby generating tangential stress and exciting body waves and surface acoustic waves in the material.

[0119] When the laser-electromagnetic ultrasonic resonance thickness measurement method is used for thickness measurement, based on the above-mentioned metal material performance detection system, a broadband ultrasonic signal is excited by a laser source. When the thickness of the test piece is equal to an integer multiple of half the wavelength, the ultrasonic wave is superimposed inside the test piece to form a standing wave. If the ultrasonic wave frequency propagating inside the metal material sample is equal to its natural frequency, the metal material sample will resonate to form a superimposed signal with stronger energy, resulting in a significant change in the specific frequency of the frequency domain signal. The thickness of the metal material sample can be calculated by using the frequency domain difference relationship between the mth resonant frequency point and the nth resonant frequency point of the resonant spectrum signal:

[0120]

[0121] Where d is the thickness of the metal sample, f m 、f n are the frequency magnitudes of the mth resonant frequency point and the nth resonant frequency point respectively, m>n≥1.

[0122] In other embodiments, the thickness of the metal material sample may be determined by other methods or measuring instruments, and then the ultrasonic velocity in the metal material sample may be calculated according to the above formula.

[0123] The embodiments of the present application also provide a method for characterizing the performance of a metal material sample. The impact of metal fatigue damage on acoustic properties has always been a long-standing problem in the field of acoustics. The appearance and expansion of dislocations and microcracks will have a certain impact on the sound velocity and sound attenuation inside metal materials. Dislocation refers to an internal microscopic defect of a crystalline material, that is, a local irregular arrangement of atoms. Due to viscosity and energy dissipation, dislocations will vibrate with phase lag under the action of ultrasonic waves, reducing the wave velocity of ultrasonic waves. At the same time, dislocations are also the main source of attenuation changes. In fatigue experiments, dislocations play an important role in the expansion of cracks and can produce extremely high stress areas at the tip of the crack.

[0124] According to the resonant frequency points of the resonant spectrum signal obtained above, at the resonant frequency points of different orders, the shape, size and amplitude of the resonant spectrum signal are closely related to the sound velocity and sound attenuation of the material. The sound velocity and sound attenuation inside the metal material sample (such as a metal sheet) will change in different damage states, and the sound velocity and sound attenuation are closely related to the dislocation density and length of the material. Accurately measuring the frequency point changes of the resonant spectrum signal and comparing them can achieve damage evaluation of the metal material sample. In addition, by measuring and drawing the resonant spectrum curve for the metal material sample, a resonant spectrum database of metal material samples in different damage states can be established, and the performance characterization of the metal material sample can be achieved by comparing the resonant spectrum database.

[0125] The present application proposes a method for detecting corrosion and thinning of high-temperature alloy materials using the laser-electromagnetic ultrasonic resonance method. The detection method combines laser ultrasonic excitation with electromagnetic ultrasonic reception to achieve true non-contact detection. At the same time, the resonance technology is integrated and the frequency domain detection technology method is used to realize online testing of corrosion and thinning of thin plate materials. The amplitude of the detection signal can be greatly improved, and the problem of low transducer efficiency of electromagnetic ultrasonic detection can be overcome.

[0126] The laser-electromagnetic ultrasonic detection method proposed in this application has the characteristics of non-contact, small size and high temperature resistance, and is suitable for non-destructive testing in harsh environments such as high temperature and confined space. It has the advantages of laser ultrasonic broadband excitation and can utilize the low cost of electromagnetic ultrasound and the low requirements on the surface of the detection material. The laser-electromagnetic acoustic resonance detection method that integrates the resonance detection technology further makes up for the disadvantage of the low signal-to-noise ratio of the laser electromagnetic ultrasonic detection technology, and can realize real-time online detection in high temperature vibration environments.

[0127] The above description of the embodiments of the present application is only a partial embodiment of the present application, which is used to enable professionals in the field to implement or use the content of the present application, and is not used to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A metal material performance detection sensor, characterized in that: It includes an electromagnetic ultrasonic transducer EMAT and a magnetic focusing ring; When in use, the EMAT and the magnetic focusing ring are respectively placed on both sides of the metal material sample; the laser emitted by the laser passes through the magnetic focusing ring to generate an ultrasonic signal in the metal material sample and is finally received by the EMAT.

2. The metal material performance detection sensor according to claim 1, characterized in that: The EMAT comprises a stepped permanent magnet and a coil; The step permanent magnet comprises a first permanent magnet and a second permanent magnet which are coaxially arranged; the first permanent magnet and the second permanent magnet are both cylindrical, the first permanent magnet is arranged on the second permanent magnet, and the diameter of the first permanent magnet is smaller than the diameter of the second permanent magnet; The coil is arranged at the front end of the first permanent magnet.

3. The metal material performance detection sensor according to claim 2, characterized in that: The permanent magnets of the EMAT and the magnetic focusing ring are both SmCo permanent magnets that can withstand a high temperature of 350°C.

4. The metal material property detection sensor according to claim 3, characterized in that: The coil is a high-temperature resistant ceramic silver coil; the step permanent magnet and the coil are assembled in a shell with an opening at the front end, and high-temperature resistant ceramic gel is filled between the shell and the step permanent magnet and the coil; a mica sheet is arranged between the coil and the front end of the shell.

5. The metal material property detection sensor according to claim 1, characterized in that: The magnetic focusing ring is in the shape of a circular column and is evenly divided into two parts, an upper part and an lower part, along the axial direction. The upper part is magnetized to an N pole and the lower part is magnetized to an S pole.

6. The metal material property detection sensor according to claim 1, characterized in that: The magnetic focusing ring includes a third permanent magnet, a fourth permanent magnet and a fifth permanent magnet; The third permanent magnet is in the shape of a circular column with equal inner diameters at the top and bottom; The fourth permanent magnet is in the shape of a circular column with a large inner diameter at the upper part and a small inner diameter at the lower part; The fifth permanent magnet is in the shape of a circular column with equal inner diameters at the top and bottom; The third permanent magnet, the fourth permanent magnet and the fifth permanent magnet are coaxially arranged; The height of the third permanent magnet is equal to that of the fourth permanent magnet, and the bottom surfaces are on the same plane; the third permanent magnet is sleeved outside the fourth permanent magnet; The fifth permanent magnet is arranged on the lower part of the fourth permanent magnet; the outer diameter of the fifth permanent magnet is equal to the inner diameter of the upper part of the fourth permanent magnet; the inner diameter of the fifth permanent magnet is equal to the inner diameter of the lower part of the fourth permanent magnet; the height of the fifth permanent magnet is less than the height of the upper part of the fourth permanent magnet; The longitudinal section of the magnetic focusing ring is divided into two symmetrical parts; the third permanent magnet, the fourth permanent magnet and the fifth permanent magnet in the left part are magnetized to S pole, N pole and S pole respectively, and the third permanent magnet, the fourth permanent magnet and the fifth permanent magnet in the right part are magnetized to N pole, S pole and N pole respectively.

7. The metal material property detection sensor according to claim 1, characterized in that: The magnetic concentrator ring includes a sixth permanent magnet, a seventh permanent magnet and a soft magnetic concentrator; The sixth permanent magnet, the seventh permanent magnet and the soft magnetic concentrator are all in the shape of a circular column; The sixth permanent magnet, the seventh permanent magnet and the soft magnetic concentrator are coaxially arranged; The sixth permanent magnet is magnetized along the axial direction and is divided into two parts, the upper part is magnetized to an N pole, and the lower part is magnetized to an S pole; The sixth permanent magnet is placed on the soft magnetic concentrator; The seventh permanent magnet and the soft magnetic concentrator are of equal height, and their bottom surfaces are on the same plane; the seventh permanent magnet is sleeved outside the soft magnetic concentrator; The inner diameter of the soft magnetic concentrator is equal to the inner diameter of the sixth permanent magnet; the seventh permanent magnet is magnetized radially and is divided into an inner part and an outer part; the outer diameter of the soft magnetic concentrator is equal to the inner diameter of the seventh permanent magnet and is smaller than the outer diameter of the sixth permanent magnet; the outer diameter of the inner part of the seventh permanent magnet is larger than the outer diameter of the sixth permanent magnet. The outer portion of the seventh permanent magnet is magnetized to an N pole, and the inner portion of the seventh permanent magnet is magnetized to an S pole.

8. A metal material performance detection system, characterized in that: It comprises a laser and a metal material performance detection sensor as described in any one of claims 1 to 7; The laser is used as an excitation part, and the metal material performance detection sensor is used as a receiving part; When in use, the laser emitted by the laser passes through the magnetic focusing ring to generate an ultrasonic signal in the metal material sample, which is finally received by the EMAT; the metal material performance test result is calculated based on the signal collected by the EMAT.

9. The system according to claim 8, characterized in that The laser is provided with a multi-joint rotating shaft mechanical light-guiding arm; the laser emitted by the laser is guided to the to-be-tested area of ​​the metal material sample through the multi-joint rotating shaft mechanical light-guiding arm, thereby exciting ultrasonic waves; The system also includes an eddy current heater for heating the metal material sample; The system also includes a three-dimensional vibration platform for placing metal material samples and simulating vibration environment.

10. The system according to claim 9, characterized in that The system also includes an XZ axis two-dimensional scanning platform for installing the EMAT to achieve two-dimensional scanning of the metal material sample.

11. The system according to claim 10, characterized in that The system also includes an impedance matcher, a preamplifier, a data acquisition card and a computer connected in sequence; the impedance matcher is connected to the EMAT; the impedance matcher is used to adjust the matching capacitance and inductance parameters of the EMAT coil to maximize the amplitude and signal-to-noise ratio of the received signal while increasing the frequency bandwidth of the resonant signal; The resonance signal then passes through the preamplifier and the data acquisition card, and the data acquisition card transmits the signal to the computer to obtain the required resonance spectrum signal.

12. A method for detecting properties of metal materials, characterized in that: Based on the metal material performance detection system described in claim 11, the resonance spectrum signal is collected, and the thickness d of the metal material sample is calculated based on the resonance spectrum signal: Where c is the ultrasonic speed, f is m 、f n are the frequency magnitudes of the mth resonant frequency point and the nth resonant frequency point respectively, m>n≥1.

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