Methods for detecting microcracks in ceramic products

Abstract

This application relates to the field of ceramic testing technology and provides a method for detecting microcracks in ceramic products. This method is applied to a microcrack detection system, which includes: an inflatable component, a pressure control mechanism, a degassing mechanism, a control device, and multiple acoustic emission sensors disposed on the inner wall of the ceramic product. The method includes: the control device controlling the pressure control mechanism to inflate the inflatable component placed inside the ceramic product; when the control device detects that some of the acoustic emission sensors have received acoustic emission signals, the control device controls the pressure control mechanism to stop inflating the inflatable component and controls the degassing mechanism to discharge the gas from the inflatable component; the control device determines the location of the microcrack in the ceramic product based on the time it takes for some of the acoustic emission sensors to receive the acoustic emission signals. This application can detect and determine the location of microcracks in ceramic products.

Description

Technical Field

[0001] This application belongs to the field of ceramic testing technology, and in particular relates to a method for detecting microcracks in ceramic products. Background Technology

[0002] Because the firing process of ceramic products involves many uncertainties, various defects exist both inside and outside the ceramic products. In addition, long-term external effects cause microcracks on the ceramic products to develop further, thus affecting the preservation and use of the ceramic products.

[0003] Currently, the main method for inspecting microcracks in ceramics involves tapping the ceramic sample, collecting the sound signal with a microphone, and then having a damage detection module process and analyze the collected sound signal. The spectrum of the sound signal is compared with that of high-quality ceramic to determine whether a quality defect exists. In addition, there is a method using ultrasonic testing to detect ceramic defects. The principle is that when ultrasonic waves enter an object and encounter a defect, a portion of the sound waves is reflected. The transmitter and receiver can analyze the reflected waves to detect defects with exceptional precision.

[0004] The biggest drawback of the aforementioned ultrasonic testing method is its difficulty in testing ceramic products with complex shapes and appearances. Ceramic products (such as antique ceramic jars) vary greatly in shape, limiting the application scenarios of ultrasonic testing. Common ceramic defect detection methods often require comparison with the acoustic signals of qualified ceramic products, and can only determine the presence of microcracks, not their location. However, for ceramic products that have been preserved for a long time (such as antique ceramic jars), cracks are inevitable, making it difficult to find so-called "good" products. Furthermore, the fundamental purpose of testing is not to determine the presence of defects, but to locate the microcracks, allowing for targeted maintenance and repair. Summary of the Invention

[0005] This application provides a method for detecting microcracks in ceramic products, which can solve the problem of being unable to determine the location of microcracks in ceramic products.

[0006] This application provides a method for detecting microcracks in ceramic products. The method is applied to a microcrack detection system, which includes: an inflatable component, a pressure control mechanism, an air release mechanism, a control device, and multiple acoustic emission sensors disposed on the inner wall of the ceramic product.

[0007] The air outlet of the air pressure control mechanism is connected to the air inlet of the inflatable component, the air inlet of the air release mechanism is connected to the air inlet, and the control equipment is connected to the control terminal of the air pressure control mechanism, the control terminal of the air release mechanism, and the output terminal of each of the multiple acoustic emission sensors.

[0008] The methods include:

[0009] The control equipment controls the air pressure control mechanism to inflate the inflatable components placed inside the ceramic product;

[0010] When the control device detects that some of the multiple acoustic emission sensors have received acoustic emission signals, it controls the air pressure control mechanism to stop inflating the inflatable component and controls the unloading mechanism to discharge the gas inside the inflatable component.

[0011] The control equipment determines the location of microcracks in ceramic products based on the time it takes for some acoustic emission sensors to receive acoustic emission signals.

[0012] Optionally, the plurality of acoustic emission sensors include: a first acoustic emission sensor, a second acoustic emission sensor, a third acoustic emission sensor, and a fourth acoustic emission sensor;

[0013] The distance between the first acoustic emission sensor and the top of the ceramic product is H / 5, the distance between the second acoustic emission sensor and the top of the ceramic product is H / 5, and there is a first preset distance between the first acoustic emission sensor and the second acoustic emission sensor; the distance between the third acoustic emission sensor and the bottom of the ceramic product is H / 7, the distance between the fourth acoustic emission sensor and the bottom of the ceramic product is H / 7, and there is a second preset distance between the third acoustic emission sensor and the fourth acoustic emission sensor, where H represents the height of the ceramic product.

[0014] Optionally, before the control device controls the air pressure control mechanism to inflate the inflatable component placed inside the ceramic product, the method further includes:

[0015] The control equipment detects whether some of the multiple acoustic emission sensors receive acoustic emission signals.

[0016] When the control device detects that some of the acoustic emission sensors have received acoustic emission signals, the control device determines the location of the microcracks in the ceramic product based on the time when some of the acoustic emission sensors received the acoustic emission signals.

[0017] When the control device detects that some acoustic emission sensors have not received acoustic emission signals, it enters the step of controlling the air pressure control mechanism to inflate the inflatable components placed inside the ceramic product.

[0018] Optionally, the control device determines the location of microcracks in the ceramic product based on the time it takes for some acoustic emission sensors to receive acoustic emission signals, including:

[0019] The control device acquires the distance between each acoustic emission sensor and the emission point of the acoustic emission signal in a subset of acoustic emission sensors;

[0020] The location of the launch point is determined based on the obtained distance;

[0021] The location of the emission point is used as the location of the microcrack in the ceramic product.

[0022] Optionally, some acoustic emission sensors include a first target acoustic emission sensor, a second target acoustic emission sensor, and a third target acoustic emission sensor;

[0023] The control device acquires the distance between each acoustic emission sensor and the emission point of the acoustic emission signal, including:

[0024] Control equipment through formula Calculate the distance r1 between the acoustic emission sensor of the first target and the emission point of the acoustic emission signal;

[0025] Control equipment through formula Calculate the distance r2 between the acoustic emission sensor of the second target and the emission point of the acoustic emission signal;

[0026] Control equipment through formula Calculate the distance r3 between the acoustic emission sensor of the third target and the emission point of the acoustic emission signal;

[0027] Among them, L 12 L represents the distance between the first target acoustic emission sensor and the second target acoustic emission sensor. 13 Δt represents the distance between the acoustic emission sensors of the first and third targets. 12 Δt represents the time difference between the time when the acoustic emission sensor of the first target receives the acoustic emission signal and the time when the acoustic emission sensor of the second target receives the acoustic emission signal. 13 L represents the time difference between the time when the acoustic emission sensor of the first target receives the acoustic emission signal and the time when the acoustic emission sensor of the third target receives the acoustic emission signal. 23 Δt represents the distance between the acoustic emission sensors of the second and third targets. 23 This represents the time difference between the time when the acoustic emission sensor of the second target receives the acoustic emission signal and the time when the acoustic emission sensor of the third target receives the acoustic emission signal.

[0028] Optionally, the air pressure control mechanism includes: a first air pump, a first motor, a first force transmission rod, a second air pump, a second motor, a second force transmission rod, and an air supply pipe;

[0029] The outlet of the first air pump is connected to the first air inlet of the air supply pipe, the outlet of the second air pump is connected to the second air inlet of the air supply pipe, and the outlet of the air supply pipe is connected to the inflation port of the inflatable component.

[0030] The first air pump has a first signal trigger switch on the end of the cylinder away from the first air inlet. The output shaft of the first motor is connected to the piston rod of the first air pump through the first force transmission rod. The control end of the first motor is connected to the control device. One end of the piston rod of the first air pump has a piston head, and the other end has a first metal rod.

[0031] The second air pump has a second signal trigger switch on the end of its cylinder away from the second air inlet. The output shaft of the second motor is connected to the piston rod of the second air pump through the second force transmission rod. The control end of the second motor is connected to the control equipment. One end of the piston rod of the second air pump has a piston head, and the other end has a second metal rod.

[0032] Optionally, the control device controls the air pressure control mechanism to inflate the inflatable components placed inside the ceramic product, including:

[0033] The control device controls the first motor to drive the piston rod of the first air pump to move toward the first air inlet via the first force transmission rod; wherein, when the first metal rod contacts the first signal trigger switch, the first signal trigger switch sends a first control signal to the control device;

[0034] After receiving the first control signal, the control device controls the first motor to drive the piston rod of the first air pump to move away from the first air inlet via the first force transmission rod, and at the same time controls the second motor to drive the piston rod of the second air pump to move towards the second air inlet via the second force transmission rod; wherein, when the second metal rod contacts the second signal trigger switch, the second signal trigger switch sends the second control signal to the control device;

[0035] After receiving the second control signal, the control device controls the second motor to drive the piston rod of the second air pump to move away from the second air inlet via the second force transmission rod. At the same time, the control device returns to the step of controlling the first motor to drive the piston rod of the first air pump to move towards the first air inlet via the first force transmission rod.

[0036] Optionally, the venting mechanism includes a pressure relief pipe and a pressure relief valve located in the middle of the pressure relief pipe. The air inlet of the pressure relief pipe is connected to the air filling port. The exhaust port of the pressure relief pipe and the pressure relief valve are both located outside the ceramic product, and the control end of the pressure relief valve is connected to the control equipment.

[0037] Optionally, the microcrack detection system also includes a display device, with the output of each of the multiple acoustic emission sensors connected to the input of the display device.

[0038] Optionally, the microcrack detection system may also include an elastic retaining ring, which is fitted over the air inlet of the inflatable component.

[0039] The above-mentioned solution in this application has the following beneficial effects:

[0040] In the embodiments of this application, by inflating the inflatable component placed inside the ceramic product, the ceramic product is pressurized, causing the microcracks in the ceramic product to deform due to stress concentration. The deformation energy at the microcracks accumulates to a certain extent and is released in the form of elastic stress waves. When some of the multiple acoustic emission sensors installed on the inner wall of the ceramic product receive the elastic stress waves (i.e., acoustic emission signals), the inflation of the inflatable component is stopped, the gas inside the inflatable component is discharged, and the location of the microcracks in the ceramic product is detected based on the time when some acoustic emission sensors receive the acoustic emission signals, thus quickly and accurately determining the location of the microcracks in the ceramic product.

[0041] Other beneficial effects of this application will be described in detail in the following detailed description section. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0043] Figure 1 A flowchart illustrating a method for detecting microcracks in ceramic products according to an embodiment of this application;

[0044] Figure 2 This is a left view of a ceramic article equipped with an acoustic emission sensor according to an embodiment of this application;

[0045] Figure 3 This is a front view of a ceramic article equipped with an acoustic emission sensor according to an embodiment of this application;

[0046] Figure 4 This is a schematic diagram showing the position of the acoustic emission sensor and the emission point according to an embodiment of this application;

[0047] Figure 5 This is a schematic diagram of the microcrack detection system and ceramic product provided in an embodiment of this application;

[0048] Figure 6 This is a schematic diagram of the unloading mechanism provided in one embodiment of this application.

[0049] [Explanation of Labels in the Attached Image]

[0050] 10. First acoustic emission sensor; 20. Second acoustic emission sensor; 30. Third acoustic emission sensor; 40. Fourth acoustic emission sensor; 50. Ceramic product; 601. First air pump; 602. First motor; 603. First force transmission rod; 604. Second air pump; 605. Second motor; 606. Second force transmission rod; 607. Air supply pipe; 608. Inflatable component; 609. First signal trigger switch; 610. Piston rod; 611. First metal rod; 612. Second signal trigger switch; 613. Piston rod; 614. Second metal rod; 615. Loading platform; 616. Pressure relief pipe; 617. Pressure relief valve; 618. Elastic retaining ring. Detailed Implementation

[0051] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0052] It should be understood that, when used in this application specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or a collection thereof.

[0053] It should also be understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0054] As used in this application specification and the appended claims, the term "if" may be interpreted, depending on the context, as "when," "once," "in response to determination," or "in response to detection." Similarly, the phrase "if determined" or "if detected [the described condition or event]" may be interpreted, depending on the context, as meaning "once determined," "in response to determination," "once detected [the described condition or event]," or "in response to detection [the described condition or event]."

[0055] Furthermore, in the description of this application and the appended claims, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0056] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0057] Most common methods for detecting ceramic defects require comparison with the acoustic signals of qualified ceramic products, and can only determine whether there are microcracks in the ceramic products, but cannot determine the location of the microcracks.

[0058] To address the aforementioned problems, this application embodiment utilizes the principle of acoustic emission to detect the location of microcracks in ceramic products. Specifically, this application embodiment uses a microcrack detection system to inflate an inflatable component placed inside the ceramic product, pressurizing the ceramic product and causing stress concentration at the microcracks, resulting in deformation. The elastic stress wave released after the deformation energy at the microcracks accumulates to a certain extent is used to quickly and accurately determine the location of the microcracks in the ceramic product.

[0059] It should be noted that acoustic emission is a non-destructive testing method that determines the degree of internal damage to a structure based on stress waves emitted from within the structure. When an object is subjected to external forces or internal stresses, the defective or structurally abnormal parts deform due to stress concentration, and a portion of its stored energy is released in the form of elastic stress waves.

[0060] The method for detecting microcracks in ceramic products provided in this application will be described exemplarily below with reference to specific embodiments.

[0061] This application provides a method for detecting microcracks in ceramic products. The method is applied to a microcrack detection system, which includes: an inflatable component, a pressure control mechanism, a degassing mechanism, a control device, and multiple acoustic emission sensors disposed on the inner wall of the ceramic product.

[0062] The air outlet of the air pressure control mechanism is connected to the air inlet of the inflatable component, the air inlet of the unloading mechanism is connected to the air inlet, and the control equipment is connected to the control end of the air pressure control mechanism, the control end of the unloading mechanism, and the output end of each of the multiple acoustic emission sensors.

[0063] In some embodiments of this application, the control device possesses the functions of a preamplifier, data acquisition and processing system, and recording, analysis, and display system typical of acoustic emission detectors. It determines whether to transmit commands to the pressure control mechanism, unloading mechanism, etc., through internal program settings. Specifically, the control device can be a terminal device such as a tablet computer, laptop computer, ultra-mobile personal computer (UMPC), netbook, or personal digital assistant (PDA). It should be noted that this application does not impose any limitations on the specific type of control device.

[0064] like Figure 1 As shown in the embodiments of this application, the method for detecting microcracks in ceramic products includes the following steps:

[0065] Step 11: The control equipment controls the air pressure control mechanism to inflate the inflatable components placed inside the ceramic product.

[0066] In some embodiments of this application, before microcrack detection of ceramic products, an inflatable component can be placed inside the ceramic product so that the ceramic product can be pressurized by inflating the inflatable component during microcrack detection.

[0067] Specifically, in some embodiments of this application, the control device can control the air pressure control mechanism to inflate the inflatable component by sending control commands to the air pressure control mechanism.

[0068] As an optional example, to facilitate rapid pressurization of ceramic products, ensure perfect conformity to the inner walls of ceramic products of various shapes throughout the pressurization process, and apply a controllable, uniformly distributed load, the aforementioned inflatable component can be a balloon. The size of the balloon depends on the volume of the ceramic product. Specifically, for ceramic products with a volume of less than 1L, a 5-inch balloon can be used; for ceramic products with a volume of 1L to 8L, a 10-inch balloon can be used; and for ceramic products with a volume exceeding 8L, an 18-inch balloon can be used.

[0069] Step 12: When the control device detects that some of the multiple acoustic emission sensors have received acoustic emission signals, it controls the air pressure control mechanism to stop inflating the inflatable component and controls the unloading mechanism to discharge the gas inside the inflatable component.

[0070] In some embodiments of this application, during the process of inflating the inflatable component and pressurizing the ceramic product, defects or structurally abnormal areas (i.e., microcracks) in the ceramic product will deform due to stress concentration (the deformation energy at this location will accumulate to a certain extent and then be released in the form of elastic stress waves). After the elastic stress waves are released, the acoustic emission sensor on the inner wall of the ceramic product can receive the elastic stress waves (i.e., acoustic emission signals) and output the received acoustic emission signals to the control device (after receiving the acoustic emission signals, the control device amplifies the acoustic emission signals, eliminates noise, etc., leaving a useful signal, and determines the location of the microcracks based on the useful signal).

[0071] The number and placement of acoustic emission sensors on the inner wall of the ceramic product can be determined based on the size and shape of the product. It should be noted that the total coverage area of ​​all acoustic emission sensors on the inner wall of the ceramic product must cover the entire product, i.e., achieve full coverage.

[0072] Step 13: The control device determines the location of the microcracks in the ceramic product based on the time it takes for some acoustic emission sensors to receive acoustic emission signals.

[0073] In some embodiments of this application, when the control device receives (i.e. detects) acoustic emission signals from some of the multiple acoustic emission sensors, it indicates that the location of the microcrack is closer to these acoustic emission sensors and farther from the other acoustic emission sensors. This means the other acoustic emission sensors may not receive the acoustic emission signal, or the received signal is extremely weak (negligible). In this case, the location of the microcrack in the ceramic product can be determined based on the time it takes for these acoustic emission sensors to receive the acoustic emission signal.

[0074] To avoid damaging ceramic products during the testing process, once it is confirmed that some acoustic emission sensors have received acoustic emission signals, the pressurization of the ceramic products must be stopped. This means controlling the air pressure control mechanism to stop inflating the inflatable components and controlling the degassing mechanism to discharge the gas from the inflatable components.

[0075] It should be noted that there is no strict order between steps 12 and 13 above.

[0076] Therefore, in some embodiments of this application, by inflating the inflatable component placed inside the ceramic product, the ceramic product is pressurized, causing the microcracks in the ceramic product to deform due to stress concentration. Part of the energy stored in this deformation is released in the form of elastic stress waves. When some of the multiple acoustic emission sensors installed on the inner wall of the ceramic product receive the elastic stress waves (i.e., acoustic emission signals), the inflation of the inflatable component is stopped, the gas inside the inflatable component is discharged, and the location of the microcracks in the ceramic product is detected based on the time when some acoustic emission sensors receive the acoustic emission signals, thus quickly and accurately determining the location of the microcracks in the ceramic product.

[0077] It should be noted that, due to the high amplitude and easily distinguishable noise characteristics of acoustic emission intensity during crack propagation in ceramic materials, acoustic emission is a very suitable method for determining microcracks in ceramic products. It offers advantages such as simple operation, obvious results, accurate positioning, and the ability to identify microcracks of various sizes.

[0078] The above-mentioned method and system for detecting microcracks in ceramic products are described below with reference to specific embodiments.

[0079] like Figures 2 to 3 As shown, the aforementioned plurality of acoustic emission sensors include: a first acoustic emission sensor 10, a second acoustic emission sensor 20 (in... Figure 3 In the diagram, the second acoustic emission sensor 20 overlaps with the first acoustic emission sensor 10 (only the first acoustic emission sensor 10 is labeled in the figure), the third acoustic emission sensor 30, and the fourth acoustic emission sensor 40 (in...). Figure 2 In the diagram, the fourth acoustic emission sensor 40 overlaps with the third acoustic emission sensor 30; only the third acoustic emission sensor 30 is labeled in the figure.

[0080] The distance between the first acoustic emission sensor 10 and the top of the ceramic product 50 is H / 5, the distance between the second acoustic emission sensor 20 and the top of the ceramic product 50 is H / 5, and there is a first preset distance between the first acoustic emission sensor 10 and the second acoustic emission sensor 20 (which can be set according to the shape and size of the ceramic product 50); the distance between the third acoustic emission sensor 30 and the bottom of the ceramic product 50 is H / 7, the distance between the fourth acoustic emission sensor 40 and the bottom of the ceramic product 50 is H / 7, and there is a second preset distance between the third acoustic emission sensor 30 and the fourth acoustic emission sensor 40 (which can be set according to the shape and size of the ceramic product 50), where H represents the height of the ceramic product 50.

[0081] It should be noted that for ceramic products of normal size and specifications, 50 only requires... Figure 2 and Figure 3Four acoustic emission sensors are arranged as shown. The first acoustic emission sensor 10 and the second acoustic emission sensor 20 are symmetrically arranged at a distance H / 5 from the top of the ceramic product 50, and the third acoustic emission sensor 30 and the fourth acoustic emission sensor 40 are symmetrically arranged at a distance H / 7 from the bottom of the ceramic product 50. For ceramic products 50 of different sizes, the positions and number of acoustic emission sensors can be adjusted according to the size of their top and bottom. If the volume is too large and the acoustic emission sensors cannot completely cover the entire surface of the ceramic product 50, the number of acoustic emission sensors should be increased, arranged according to the principle of full coverage and staggered arrangement of adjacent layers of acoustic emission sensors.

[0082] Before installing the acoustic emission sensor on the inner wall of a ceramic product, it is necessary to test whether the sensor is working properly. Installation can proceed only after confirming that it is functioning correctly. During installation, a coupling agent (such as Vaseline) can be applied to the acoustic emission sensor to ensure good contact between the sensor and the ceramic product. Then, a clamp can be used to install the acoustic emission sensor onto the inner wall of the ceramic product.

[0083] In some embodiments of this application, before arranging the acoustic emission sensors and inflating the inflatable components, the presence of microcracks in the ceramic product can be detected. Specifically, the ceramic product can be placed on the loading platform of the microcrack detection system and left to stand for a period of time. Then, the control device detects whether some of the multiple acoustic emission sensors receive acoustic emission signals. Specifically, when the control device detects that some acoustic emission sensors do not receive acoustic emission signals, it initiates a step where the control device controls the air pressure control mechanism to inflate the inflatable components placed inside the ceramic product. Conversely, when the control device detects that some acoustic emission sensors receive acoustic emission signals, it determines the location of the microcracks in the ceramic product based on the time it takes for some of the acoustic emission sensors to receive the signals.

[0084] In some embodiments of this application, the control device determines the location of microcracks in a ceramic product based on the time it takes for a portion of the acoustic emission sensors to receive acoustic emission signals. The specific implementation includes the following steps:

[0085] Step 1: The control device acquires the distance between each acoustic emission sensor and the emission point of the acoustic emission signal in a subset of acoustic emission sensors.

[0086] In some embodiments of this application, the aforementioned partial acoustic emission sensor includes three acoustic emission sensors among the plurality of acoustic emission sensors, denoted as the first target acoustic emission sensor, the second target acoustic emission sensor, and the third target acoustic emission sensor.

[0087] Accordingly, in some embodiments of this application, the control device can be controlled by formula Calculate the distance r1 between the acoustic emission sensor of the first target and the emission point of the acoustic emission signal; simultaneously, it can be calculated using the formula... The distance r2 between the acoustic emission sensor of the second target and the emission point of the acoustic emission signal can be calculated using the formula. Calculate the distance r3 between the acoustic emission sensor of the third target and the emission point of the acoustic emission signal.

[0088] Among them, L 12 L represents the distance between the first target acoustic emission sensor and the second target acoustic emission sensor. 13 Δt represents the distance between the acoustic emission sensors of the first and third targets. 12 Δt represents the time difference between the time when the acoustic emission sensor of the first target receives the acoustic emission signal and the time when the acoustic emission sensor of the second target receives the acoustic emission signal. 13 L represents the time difference between the time when the acoustic emission sensor of the first target receives the acoustic emission signal and the time when the acoustic emission sensor of the third target receives the acoustic emission signal. 23 Δt represents the distance between the acoustic emission sensors of the second and third targets. 23 This represents the time difference between the time when the acoustic emission sensor of the second target receives the acoustic emission signal and the time when the acoustic emission sensor of the third target receives the acoustic emission signal.

[0089] Step two: Determine the location of the launch point based on the obtained distance.

[0090] In some embodiments of this application, the process of determining the location of the aforementioned launch point can be as follows: Figure 4 As shown, after calculating the distance r1 between the first target acoustic emission sensor S1 and the emission point of the acoustic emission signal, the distance r2 between the second target acoustic emission sensor S2 and the emission point of the acoustic emission signal, and the distance r3 between the third target acoustic emission sensor S3 and the emission point of the acoustic emission signal, a line segment a of length r1 is drawn starting from the location of the first target acoustic emission sensor S1, a line segment b of length r2 is drawn starting from the location of the second target acoustic emission sensor S2, and a line segment c of length r3 is drawn starting from the location of the third target acoustic emission sensor S3. Then, line segments a, b, and c intersect at a point (e.g., ...). Figure 5 The intersection point O in the diagram is the emission point. Since the positions of the first target acoustic emission sensor S1, the second target acoustic emission sensor S2, and the third target acoustic emission sensor S3, as well as their distances r1, r2, and r3, are all known, the position of the emission point can be determined through common geometric calculations.

[0091] Step 3: The location of the emission point is used as the location of the microcrack in the ceramic product.

[0092] In some embodiments of this application, since the acoustic emission signal is emitted from the microcracks in the ceramic product, the location of the emission point of the acoustic emission signal is the location of the microcracks in the ceramic product.

[0093] The specific structure of the microcrack detection system described above will be illustrated below with reference to specific embodiments.

[0094] like Figure 5 As shown, the above-mentioned air pressure control mechanism includes: a first air pump 601, a first motor 602, a first force transmission rod 603, a second air pump 604, a second motor 605, a second force transmission rod 606, and an air supply pipe 607.

[0095] The first air pump 601 has its outlet connected to the first air inlet of the air supply pipe 607, the second air pump 604 has its outlet connected to the second air inlet of the air supply pipe 607, and the outlet of the air supply pipe 607 is connected to the inflation port of the inflatable component 608. A first signal trigger switch 609 is installed on the end of the cylinder of the first air pump 601 away from the first air inlet. The output shaft of the first motor 602 is connected to the piston rod 610 of the first air pump 601 via a first force transmission rod 603. The control terminal of the first motor 602 is connected to the control device... The first air pump 601 has a piston head at one end of its piston rod 610 and a first metal rod 611 at the other end. The second air pump 604 has a second signal trigger switch 612 at the end of its cylinder away from the second air inlet. The output shaft of the second motor 605 is connected to the piston rod 613 of the second air pump 604 via a second force transmission rod 606. The control end of the second motor 605 is connected to a control device. The piston rod 613 of the second air pump 604 has a piston head at one end and a second metal rod 614 at the other end.

[0096] In some embodiments of this application, when detecting the location of microcracks in a ceramic product, the ceramic product can be placed on the loading platform 615 of the microcrack detection system.

[0097] In some embodiments of this application, the piston movement of both the first air pump 601 and the second air pump 604 can inject 50ml of air, and both the first air pump 601 and the second air pump 604 can be made of non-metallic materials. It is understood that the embodiments of this application do not limit the air injection volume or the materials of the first air pump 601 and the second air pump 604.

[0098] In some embodiments of this application, the first metal rod 611 and the second metal rod 614 can both be iron blocks slightly shorter than the diameter of the air pump, and the first signal trigger switch 609 and the second signal trigger switch 612 can both be non-embedded signal trigger switches (such as signal trigger switches of model E2B-M30-N30).

[0099] Based on the above structure of the air pressure control mechanism, the specific process by which the control equipment controls the air pressure control mechanism to inflate the inflatable component placed inside the ceramic product is as follows:

[0100] The first step involves the control device controlling the first motor to drive the piston rod of the first air pump towards the first air inlet via the first force transmission rod; wherein, when the first metal rod contacts the first signal trigger switch, the first signal trigger switch sends a first control signal to the control device.

[0101] In some embodiments of this application, when the control device controls the first motor to drive the piston rod of the first air pump to move toward the first air inlet, it can control the piston rod of the first air pump to compress and inject air at a speed of L / 5 per second (L is the length of the cylinder of the first air pump). After 5 seconds, the first metal rod touches the first signal trigger switch, triggering the first signal trigger switch to send an electrical signal (i.e., the aforementioned first control signal).

[0102] In the second step, after receiving the first control signal, the control device controls the first motor to drive the piston rod of the first air pump to move away from the first air inlet via the first force transmission rod, and at the same time controls the second motor to drive the piston rod of the second air pump to move towards the second air inlet via the second force transmission rod; wherein, when the second metal rod contacts the second signal trigger switch, the second signal trigger switch sends a second control signal to the control device.

[0103] That is, after receiving the first control signal, the control device controls the first motor to reverse, driving the piston rod of the first air pump to move away from the first air inlet. Simultaneously, it controls the second motor to drive the piston rod of the second air pump to compress and inject air at a speed of L / 5 per second (L is the length of the second air pump's cylinder, which is the same as the length of the first air pump's cylinder). When the second metal rod touches the second signal trigger switch, it triggers the second signal trigger switch to emit an electrical signal (i.e., the aforementioned second control signal).

[0104] The third step involves the control device, upon receiving the second control signal, controlling the second motor to drive the piston rod of the second air pump away from the second air inlet via the second force transmission rod, while simultaneously controlling the first motor to drive the piston rod of the first air pump towards the first air inlet via the first force transmission rod.

[0105] That is, after the control device receives the second control signal, the control device controls the second motor to reverse, driving the piston rod of the second air pump to move away from the second air inlet, while returning to the first step. This process is repeated to achieve alternating air injection by the first and second air pumps, ensuring a uniform and stable injection speed, and controlling it at 10mL / s, thereby avoiding damage to ceramic products due to pressure.

[0106] It should be noted that when it is necessary to stop inflating the inflatable component, the control device can stop inflating the inflatable component by controlling the first motor and the second motor to stop working.

[0107] like Figure 6 As shown, the aforementioned venting mechanism includes a pressure relief pipe 616 and a pressure relief valve 617 disposed in the middle of the pressure relief pipe 616. The air inlet of the pressure relief pipe 616 is connected to the air filling port, and both the exhaust port of the pressure relief pipe 616 and the pressure relief valve 617 are located outside the ceramic product, and the control end of the pressure relief valve 617 is connected to the control equipment.

[0108] In some embodiments of this application, when the control device detects that some of the acoustic emission sensors among a plurality of acoustic emission sensors have received acoustic emission signals, it can send a control signal to the pressure relief valve to control the pressure relief valve to be in an open state, so that the gas in the inflatable component can be discharged through the pressure relief pipe, thereby achieving the purpose of pressure relief.

[0109] In some embodiments of this application, such as Figure 5 As shown, the microcrack detection system also includes an elastic retaining ring 618, which is sleeved on the outside of the air inlet of the inflatable component 608, thereby effectively preventing the gas inside the inflatable component 608 from leaking out during the pressurization of the ceramic product.

[0110] Understandably, to ensure effective crack detection, the inflation performance of the microcrack detection system needs to be tested before pressurizing ceramic products. Specifically, the inflation port of the inflatable component can be fixed to the elastic retaining ring. After confirming that it is clamped, the control device is used to control the first and second motors to inject air into the inflatable component. Then, the expansion state of the inflatable component is observed. If the expansion state of the inflatable component is good and there is no air leakage, it indicates that the inflation performance of the microcrack detection system is good. If air leakage or explosion of the inflatable component occurs, the microcrack detection system should be inspected and repaired to ensure that the inflation performance of the microcrack detection system is in good condition.

[0111] In some embodiments of this application, the microcrack detection system further includes a display device, the input of which is connected to the output of each of the plurality of acoustic emission sensors, thereby facilitating the user to observe whether the acoustic emission sensors have collected acoustic emission signals from the display device.

[0112] It is worth mentioning that, since ceramic products generally do not spontaneously generate acoustic emission signals, this application employs a controllable pressure microcrack detection system with a certain strength and pressure-bearing capacity to pressurize the ceramic products, thereby inducing acoustic emission signals. Furthermore, by releasing pressure and quantitative control, the development of microcracks is kept within a range that does not affect the overall structure. Based on this, compared to conventional detection methods, this application has the advantages of being controllable, non-destructive, accurate, and capable of rapidly detecting microcrack areas in ceramic products.

[0113] Furthermore, common ceramic defect detection methods mostly require comparison with the acoustic signals of qualified ceramic products, and can only determine whether a ceramic product has microcracks, but cannot accurately locate the area of ​​microcracks. However, for ancient ceramic products that have been preserved for a long time (such as ancient ceramic jars), cracks are inevitable, making it difficult to find so-called "good" products. Moreover, the fundamental purpose of detection is not to determine whether ancient ceramic products have defects, but to determine the location of microcracks, thereby enabling targeted maintenance and repair. Therefore, the ceramic microcrack detection method proposed in this application can provide technical guidance for the restoration of ancient ceramic products and has significant application prospects in the field of ancient ceramic product restoration.

[0114] In addition to the restoration of ancient ceramic artifacts, the microcrack detection method for ceramic artifacts proposed in this application is also applicable to the non-destructive testing of microcracks in various brittle materials. By controlling the loading of the test piece, acoustic emission signals are obtained, and the specific area of ​​the microcrack can be deduced. Therefore, compared with commonly used detection methods, the detection method proposed in this invention has a wider range of applications.

[0115] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for detecting microcracks in ceramic products, characterized in that, The ceramic product is an ancient ceramic product, and the method is applied to a microcrack detection system. The microcrack detection system includes: an inflatable component, an air pressure control mechanism, an air release mechanism, a control device, and multiple acoustic emission sensors disposed on the inner wall of the ceramic product. The air outlet of the air pressure control mechanism is connected to the air inlet of the inflatable component, the air inlet of the air release mechanism is connected to the air inlet, and the control device is connected to the control terminal of the air pressure control mechanism, the control terminal of the air release mechanism, and the output terminal of each of the multiple acoustic emission sensors. The method includes: The control device controls the air pressure control mechanism to inflate the inflatable component placed inside the ceramic product to pressurize the ceramic product. Throughout the pressurization process, the inflatable component is in perfect contact with the inner wall of the ceramic product, applying a controllable and uniformly distributed load. When the control device detects that some of the multiple acoustic emission sensors have received acoustic emission signals, it controls the air pressure control mechanism to stop inflating the inflatable component and controls the degassing mechanism to discharge the gas inside the inflatable component. The control device determines the location of the microcrack in the ceramic product based on the time when the acoustic emission signal is received by the partial acoustic emission sensor. The plurality of acoustic emission sensors are: a first acoustic emission sensor, a second acoustic emission sensor, a third acoustic emission sensor, and a fourth acoustic emission sensor; The distance between the first acoustic emission sensor and the top of the ceramic product is H / 5. The distance between the second acoustic emission sensor and the top of the ceramic product is H / 5, and there is a first preset distance between the first acoustic emission sensor and the second acoustic emission sensor; the distance between the third acoustic emission sensor and the bottom of the ceramic product is H / 7, the distance between the fourth acoustic emission sensor and the bottom of the ceramic product is H / 7, and there is a second preset distance between the third acoustic emission sensor and the fourth acoustic emission sensor, where H represents the height of the ceramic product; Before the control device controls the air pressure control mechanism to inflate the inflatable component placed inside the ceramic product, the method further includes: The control device detects whether some of the multiple acoustic emission sensors receive an acoustic emission signal. When the control device detects that some of the acoustic emission sensors have received acoustic emission signals, the control device determines the location of the microcracks in the ceramic product based on the time when the acoustic emission sensors receive the acoustic emission signals. When the control device detects that some of the acoustic emission sensors have not received an acoustic emission signal, it proceeds to the step of controlling the air pressure control mechanism to inflate the inflatable component placed inside the ceramic product. The control device determines the location of the microcrack in the ceramic product based on the time when the acoustic emission signal is received by the partial acoustic emission sensor, including: The control device acquires the distance between each acoustic emission sensor in the partial acoustic emission sensor and the emission point of the acoustic emission signal; The location of the launch point is determined based on the obtained distance; The location of the emission point is taken as the location of the microcrack in the ceramic product; The acoustic emission sensors include a first target acoustic emission sensor, a second target acoustic emission sensor, and a third target acoustic emission sensor; The control device acquires the distance between each acoustic emission sensor in the partial acoustic emission sensors and the emission point of the acoustic emission signal, including: The control device uses the formula Calculate the distance r1 between the first target acoustic emission sensor and the emission point of the acoustic emission signal; The control device uses the formula Calculate the distance r2 between the second target acoustic emission sensor and the emission point of the acoustic emission signal; The control device uses the formula Calculate the distance r3 between the third target acoustic emission sensor and the emission point of the acoustic emission signal; Among them, L 12 L represents the distance between the first target acoustic emission sensor and the second target acoustic emission sensor. 13 Δt represents the distance between the first target acoustic emission sensor and the third target acoustic emission sensor. 12 Δt represents the time difference between the time when the first target acoustic emission sensor receives the acoustic emission signal and the time when the second target acoustic emission sensor receives the acoustic emission signal. 13 L represents the time difference between the time when the first target acoustic emission sensor receives the acoustic emission signal and the time when the third target acoustic emission sensor receives the acoustic emission signal. 23 Δt represents the distance between the second target acoustic emission sensor and the third target acoustic emission sensor. 23 This represents the time difference between the time when the second target acoustic emission sensor receives the acoustic emission signal and the time when the third target acoustic emission sensor receives the acoustic emission signal.

2. The method according to claim 1, characterized in that, The air pressure control mechanism includes: a first air pump, a first motor, a first force transmission rod, a second air pump, a second motor, a second force transmission rod, and an air supply pipe; The air outlet of the first air pump is connected to the first air inlet of the air supply pipe, the air outlet of the second air pump is connected to the second air inlet of the air supply pipe, and the air outlet of the air supply pipe is connected to the air inlet of the inflatable component. The first air pump has a first signal trigger switch on the end of its cylinder away from the first air inlet. The output shaft of the first motor is connected to the piston rod of the first air pump through the first force transmission rod. The control end of the first motor is connected to the control device. One end of the piston rod of the first air pump has a piston head, and the other end has a first metal rod. The second air pump has a second signal trigger switch on the end of its cylinder away from the second air inlet. The output shaft of the second motor is connected to the piston rod of the second air pump through the second force transmission rod. The control end of the second motor is connected to the control device. One end of the piston rod of the second air pump has a piston head, and the other end has a second metal rod.

3. The method according to claim 2, characterized in that, The control device controls the air pressure control mechanism to inflate the inflatable component placed inside the ceramic product, including: The control device controls the first motor to drive the piston rod of the first air pump to move toward the first air inlet via the first force transmission rod; wherein, when the first metal rod contacts the first signal trigger switch, the first signal trigger switch sends a first control signal to the control device; After receiving the first control signal, the control device controls the first motor to drive the piston rod of the first air pump to move away from the first air inlet via the first force transmission rod, and simultaneously controls the second motor to drive the piston rod of the second air pump to move towards the second air inlet via the second force transmission rod; wherein, when the second metal rod contacts the second signal trigger switch, the second signal trigger switch sends a second control signal to the control device; After receiving the second control signal, the control device controls the second motor to drive the piston rod of the second air pump to move away from the second air inlet via the second force transmission rod, and simultaneously returns to the step of the control device controlling the first motor to drive the piston rod of the first air pump to move towards the first air inlet via the first force transmission rod.

4. The method according to claim 1, characterized in that, The venting mechanism includes a pressure relief pipe and a pressure relief valve disposed in the middle of the pressure relief pipe. The air inlet of the pressure relief pipe is connected to the air filling port. The exhaust port of the pressure relief pipe and the pressure relief valve are both located outside the ceramic product, and the control end of the pressure relief valve is connected to the control device.

5. The method according to claim 1, characterized in that, The microcrack detection system also includes a display device, and the output of each of the multiple acoustic emission sensors is connected to the input of the display device.

6. The method according to claim 1, characterized in that, The microcrack detection system also includes an elastic retaining ring, which is sleeved on the outside of the inflation port of the inflatable component.

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