In-situ loading system and method for induction heating ultrahigh-temperature multi-atmosphere CT (Computed Tomography)

Abstract

The invention discloses an in-situ loading system and method for induction heating ultrahigh-temperature multi-atmosphere CT, and belongs to the field of high-temperature mechanical testing. The device comprises a mechanical loading testing machine, a high-temperature furnace, a clamp unit and a cooling system. The high-temperature furnace is arranged in a mechanical loading testing machine; and the clamp unit is arranged in the high-temperature furnace. A runner is further arranged in the side wall of the high-temperature furnace, and cooling water flows through the runner to form a cooling system. The mechanical loading testing machine comprises an upper servo motor, a load sensor, a supporting frame and a lower servo motor from top to bottom. The high-temperature furnace comprises a cavity internally provided with a flow channel and a cabin door. The clamp unit comprises a stretching clamp, a compression clamp, a bending clamp and a shearing clamp. According to the invention, ultrahigh-temperature rapid heating and ultrahigh-temperature in-situ loading of stretching, compression, bending, shearing and the like of a sample in a vacuum or inert 2200 DEG C / atmosphere or different oxygen partial pressure 1800 DEG C extreme environment can be realized, and in-situ three-dimensional characterization of internal damage can be realized. And high-resolution in-situ slices of the sample in an extreme environment can be obtained.

Description

Technical Field

[0001] The present invention relates to an in-situ loading system and method for induction heating ultra-high temperature multi-atmosphere CT, belonging to the field of high temperature mechanical testing. Background Art

[0002] In industries such as aerospace, automotive, and energy and power, materials are often exposed to extreme environments, such as high temperatures and oxygen. The mechanical properties of materials in these extreme environments differ significantly from those at room temperature. Therefore, studying the mechanical properties of materials in these environments and uncovering their deformation and damage mechanisms at high temperatures is crucial. The complex internal microstructure of materials further complicates their damage and failure mechanisms at high temperatures. Widely used ex situ characterization methods cannot simulate the material's actual service environment and cannot observe material behavior in real time under extreme conditions such as high temperature and high pressure. Secondly, material damage and failure are often a dynamic process that evolves gradually. Ex situ characterization methods cannot monitor the immediate changes that occur in materials under load, deformation, or environmental changes, making it difficult to capture the dynamic damage evolution of materials. Furthermore, many ex situ characterization methods, such as optical microscopy and electron microscopy, focus primarily on surface features, making it difficult to effectively analyze the internal structure and deep-seated damage. Therefore, developing test instruments and testing methods that can simulate the material's actual service environment and dynamically capture the deformation and internal damage evolution of materials is crucial for improving the safety, reliability, and service life of materials.

[0003] In-situ research based on X-CT provides an advanced three-dimensional imaging technology for material performance research. It can observe the deformation, damage and failure process of materials in real time and dynamically under complex environments. Compared with traditional surface characterization methods, it can penetrate deep into the material and reveal the evolution of its microstructure. The advantage of this technology is that it can perform multiple imaging and analysis without destroying the sample. It is especially suitable for materials that need to be tested in extreme environments such as high temperature, high pressure or special atmosphere. Through X-CT in-situ testing, the entire process of the material under conditions such as stress or high temperature can be accurately captured, from the initial microcrack generation to the final destruction, to fully understand the damage evolution mechanism of the material. The high-resolution three-dimensional images provided by this technology can detect tiny structural changes that are difficult to detect with conventional methods, which helps to identify early damage and conduct in-depth research on the microscopic mechanisms of damage and failure.

[0004] In high-temperature in-situ equipment for X-CT three-dimensional tomography, halogen lamps are usually used for heating. However, halogen lamp heating is achieved by focusing the light reflections from multiple halogen lamps to heat a focal area, which is a spherical area with a diameter of only 5 mm. The heating area of a halogen lamp is small and cannot heat the entire sample. The temperature gradient on the surface of the sample is large. The heating temperature of a halogen lamp is also usually low, not exceeding 1750°C. The operating atmosphere is single, namely vacuum and atmosphere, and it is not suitable for inert environments and atmospheres with different oxygen partial pressures. In addition, it takes about an hour to scan a round of CT slices, which places very high demands on the thermal shock resistance of the halogen lamp. If the halogen lamp is damaged during the test, it will destroy the atmosphere and temperature of the high-temperature furnace, causing the test to fail. Summary of the Invention

[0005] To address the problems of low heating temperature, small heating temperature zone, large temperature gradient on the specimen surface, and single operating atmosphere in the aforementioned halogen lamp-heated in-situ high-temperature furnace, the present invention, based on the technical solution of induction heating, aims to provide an in-situ loading system and method for ultra-high-temperature, multi-atmosphere CT using induction heating. The system comprises a mechanical loading testing machine, a high-temperature furnace, a fixture unit, and a cooling system. This system enables ultra-high-temperature rapid heating of specimens in extreme environments such as vacuum or inert atmosphere (2200°C), or at different oxygen partial pressures (1800°C), as well as ultra-high-temperature in-situ loading such as stretching, compression, bending, and shearing, as well as in-situ three-dimensional characterization of internal damage. Furthermore, high-resolution in-situ slices of specimens in extreme environments can be obtained.

[0006] One object of the present invention is achieved through the following technical solutions.

[0007] The present invention discloses an in-situ loading system for an induction heating ultra-high temperature multi-atmosphere CT, comprising a mechanical loading testing machine, a high temperature furnace, a fixture unit and a cooling system.

[0008] The high-temperature furnace is placed inside the mechanical loading testing machine and fixed via an adapter. The fixture unit is placed inside the high-temperature furnace and fixedly connected to the adapter. There are also flow channels in the side walls of the high-temperature furnace, through which cooling water flows to form a cooling system.

[0009] The mechanical loading testing machine includes an upper servo motor, a load sensor, a support frame, and a lower servo motor from top to bottom. The lower servo motor is connected to the support frame, and the upper servo motor is connected to the load sensor and coupled to the support frame to form an integrated structure for applying load to the specimen and driving the specimen to rotate.

[0010] The high-temperature furnace includes a cavity with a flow channel inside and a hatch. A through hole with a diameter of 100 mm is provided at the top and bottom of the cavity, allowing the adapter to extend into the high-temperature furnace to fix the high-temperature furnace. The side wall of the cavity is provided with a thermocouple mounting hole, a gas channel, an observation window and an X-ray transmission window. The hatch is also provided with an X-ray transmission window, and water cooling inlets and outlets are provided on the side wall of the cavity and the hatch. Water enters through the water inlet, flows in the flow channel opened in the side wall of the furnace body, and comes out from the water outlet to form a cooling system; the high-temperature furnace includes an induction coil, thermal insulation cotton and a heating element for heating and keeping the sample warm. Three small circular holes with a spacing of 90° and a diameter of 20 mm are distributed in the middle of the thermal insulation cotton and the heating element for observing the sample and measuring the temperature of the sample.

[0011] The clamp unit includes a tensile clamp, a compression clamp, a bending clamp and a shearing clamp, which can be replaced and used as needed;

[0012] The tensile fixture is divided into an upper tensile fixture and a lower tensile fixture, which are connected to the top load sensor and the bottom servo motor through adapters respectively, and are used to clamp the tensile specimen;

[0013] The compression fixture is divided into an upper compression fixture and a lower compression fixture, which are connected to the top load sensor and the bottom servo motor through adapters respectively, and are used to fix the compression specimen;

[0014] The bending fixture is divided into an upper bending fixture and a lower bending fixture. Both have the same structure and are symmetrically arranged. They are connected to the top load sensor and the bottom servo motor through adapters, respectively, to clamp the bending specimen. The bending fixture consists of a support arm and a chuck, which are movably connected by a pin. When a load is applied to the support arm, the pin rotates, driving the chuck to rotate, realizing the bending of the specimen.

[0015] The shear fixture is divided into an upper shear fixture, a loading block and a lower shear fixture. The upper shear fixture and the lower shear fixture are connected to the top load sensor and the bottom servo motor respectively through adapters; the lower shear fixture and the loading block fix the specimen through four anti-symmetrical support planes. When a load is applied to the upper shear fixture, the load is transferred to the loading block. Under the joint action of the loading block and the lower shear fixture, an anti-symmetric four-point bending load is formed, which will generate shear force at the center of the shear specimen to achieve shearing of the specimen.

[0016] The thickness of the X-ray transmission window is between 50 μm and 300 μm, and the diameter of the X-ray transmission window is 20 mm. The material of the X-ray transmission window can be replaced with aluminum alloy, boron nitride or quartz glass according to different usage functions.

[0017] Another object of the present invention is achieved through the following technical solutions.

[0018] An in-situ loading method for an induction-heated ultra-high temperature multi-atmosphere CT is implemented based on an in-situ loading system for an induction-heated ultra-high temperature multi-atmosphere CT. An in-situ loading method for an induction-heated ultra-high temperature multi-atmosphere CT comprises the following steps:

[0019] S1. Build the in-situ loading system for the induction heating ultra-high temperature multi-atmosphere CT;

[0020] S2. Connect the fixture to the load cell at the upper end and the lower servo motor at the lower end through the adapter, then place the sample in the heating element and connect the sample to the fixture to ensure that the tested part of the sample is located in the heating element;

[0021] S3. Adjust the incident height of the X-ray source so that the center of the sample is exactly in the X-ray optical path;

[0022] S4. Apply preload force to the specimen using a mechanical loading tester to ensure a stable connection between the specimen and the fixture.

[0023] S5. Connect the gas channel to a vacuum pump to extract vacuum, or directly introduce specified gas to form a vacuum environment, an inert environment, and different oxygen partial pressure environments in the high-temperature furnace.

[0024] S6. Turn on the cooling system to allow cooling water to flow through the water cooling channel of the high-temperature furnace to cool the furnace body;

[0025] S7. Install a thermocouple or infrared temperature measuring device, heat and keep the sample warm using an induction heating device, and measure and calibrate the temperature of the sample using the thermocouple or infrared temperature measuring device;

[0026] S8. Conduct high temperature in-situ testing.

[0027] S9. End the experiment.

[0028] S10. Experimental data analysis.

[0029] The inert gas in step S5 is nitrogen, argon or helium.

[0030] In step S7, the heating temperature in a vacuum or inert environment is not less than 2200° C., and the heating temperature in the atmosphere or an environment with different oxygen partial pressures is not less than 1800° C.

[0031] Beneficial effects:

[0032] 1. The present invention discloses an in-situ loading system and method for induction-heated ultra-high-temperature multi-atmosphere CT. This system balances CT high resolution, structural thermal protection, and structural strength. Based on thermal simulation and structural optimization, the cavity size of the high-temperature furnace is designed to be a rectangular parallelepiped with a length of 270 mm, a width of 150 mm, and a height of 120 mm. This greatly reduces the volume, shortens the distance from the X-ray source to the sample, improves the resolution of CT slices, and can obtain high-quality three-dimensional visualization slices.

[0033] 2. The present invention discloses an in-situ loading system and method for an induction-heated ultra-high-temperature multi-atmosphere CT. Both the induction coil and the heating element are miniaturized. The diameter of the induction coil is 80 mm and the height is 65 mm. The inner diameter of the heating element is 20 mm, the outer diameter is 32 mm, and the height is 65 mm. In order to adapt to the induction coil and the heating element, the clamp unit is also miniaturized. The length and width of the clamp unit and the corresponding sample are strictly limited to 18 mm, thereby improving the ability of the X-ray source to penetrate the sample and increasing the accuracy of in-situ characterization.

[0034] 3. The present invention discloses an in-situ loading system and method for an induction-heated ultra-high-temperature multi-atmosphere CT. The high-temperature furnace is made of stainless steel and only needs to provide an ultra-high-temperature extreme environment. It does not require load bearing and lacks an annular aluminum window. Therefore, it can achieve large load loading, with a maximum load of 20kN.

[0035] 4. The present invention discloses an in-situ loading system and method for an ultra-high-temperature, multi-atmosphere CT system using induction heating. The heating method is induction heating, and a layer of thermal insulation cotton is wrapped between the induction coil and the heating element to maximize the temperature uniformity of the cylindrical space inside the heating element with a diameter of 20 mm and a height of 65 mm, thereby providing uniform temperature over a large range.

[0036] 5. The present invention discloses an in-situ loading system and method for ultra-high-temperature, multi-atmosphere CT systems using induction heating. These systems overcome the current limitation of halogen lamp-based high-temperature CT furnaces, which typically heat at temperatures below 1750°C. The present invention's high-temperature CT furnace achieves a heating temperature of no less than 2200°C in a vacuum or inert environment and no less than 1800°C in an oxygen or atmospheric environment, far exceeding the heating temperatures of current high-temperature CT furnaces.

[0037] 6. This invention discloses an in-situ loading system and method for ultra-high-temperature, multi-atmosphere CT using induction heating. Using induction heating, a coil provides a magnetic field to the heating element. This magnetic field generates annular eddy currents within the element, ultimately forming a cylindrical, uniformly heated region within the element. This allows for unlimited heating of samples and is applicable to diverse material systems, including conductors, semiconductors, and insulators.

[0038] 7. The present invention discloses an in-situ loading system and method for induction heating ultra-high temperature multi-atmosphere CT. The designed high-temperature furnace is equipped with a vacuum pump and a gas cylinder, so it can achieve multiple atmosphere environments such as vacuum / inert / atmosphere / different oxygen partial pressures.

[0039] 8. This invention discloses an in-situ loading system and method for an induction-heated, ultra-high-temperature, multi-atmosphere CT. Conventional high-temperature CT furnaces use aluminum windows as X-ray transmission windows, which obscure the furnace's interior. The high-temperature furnace of this invention is further equipped with a quartz glass observation window, enabling real-time observation of the sample inside the furnace. It also supports non-contact measurement of the sample, such as deformation measurement using DIC, temperature measurement using an infrared thermometer, and full-field temperature measurement using a thermal imager, allowing for visualization of the sample's temperature distribution.

[0040] 9. The present invention discloses an in-situ loading system and method for ultra-high-temperature, multi-atmosphere CT using induction heating. During high-temperature in-situ scanning, the presence of a water-cooling tube may affect the distance between the radiation source and the high-temperature furnace. Furthermore, due to the small size of the high-temperature furnace, the water-cooling tube is close to the support frame of the mechanical loading tester. During induction heating, the metal support frame of the mechanical loading tester can easily become hot and damage the water-cooling tube. By designing a spring hook for the water-cooling tube, the water-cooling tube can be effectively restrained and protected during high-temperature in-situ testing, ensuring the smooth completion of the test. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 This is an overall schematic diagram of an in-situ loading system and method for an induction heating ultra-high temperature multi-atmosphere CT according to the present invention;

[0042] Figure 2 A schematic diagram of a mechanical loading testing machine for an in-situ loading system and method for induction heating ultra-high temperature multi-atmosphere CT according to the present invention;

[0043] Figure 3 A schematic diagram of a high-temperature furnace for an in-situ loading system and method for induction heating ultra-high temperature multi-atmosphere CT according to the present invention;

[0044] Figure 4 A schematic diagram of the interior of a high-temperature furnace for an in-situ loading system and method for induction heating ultra-high temperature multi-atmosphere CT according to the present invention;

[0045] Figure 5 A schematic diagram of a sealing flange of an in-situ loading system and method for an induction-heated ultra-high temperature multi-atmosphere CT according to the present invention;

[0046] Figure 6 A schematic diagram of the thermal insulation cotton of an in-situ loading system and method for induction heating ultra-high temperature multi-atmosphere CT according to the present invention;

[0047] Figure 7A schematic diagram of a heating element of an in-situ loading system and method for induction heating ultra-high temperature multi-atmosphere CT according to the present invention;

[0048] Figure 8 A schematic diagram of a tensile fixture for an in-situ loading system and method for induction heating ultra-high temperature multi-atmosphere CT according to the present invention;

[0049] Figure 9 A schematic diagram of a compression fixture for an in-situ loading system and method for induction heating ultra-high temperature multi-atmosphere CT according to the present invention;

[0050] Figure 10 A schematic diagram of a bending fixture for an in-situ loading system and method for an induction-heated ultra-high temperature multi-atmosphere CT according to the present invention;

[0051] Figure 11 A schematic diagram of a shear fixture for an in-situ loading system and method for induction heating ultra-high temperature multi-atmosphere CT according to the present invention;

[0052] Among them: 1-mechanical loading test machine, 2-high temperature furnace, 3-upper servo motor, 4-load sensor, 5-support frame, 6-lower servo motor, 7-adapter, 8-high temperature furnace hatch, 9-cabin door X-ray transmission window, 10-cabin door water cooling inlet, 11-cabin door water cooling outlet, 12-high temperature furnace cavity, 13-thermocouple installation hole, 14-high temperature furnace cavity water cooling inlet, 15-high temperature furnace cavity water cooling outlet, 16-gas channel, 17-high temperature furnace cavity X-ray transmission window, 18- Observation window, 19—sealing flange, 20—upper tensile fixture, 21—tensile specimen, 22—lower tensile fixture, 23—induction coil, 24—thermal insulation cotton, 25—heating element, 26—upper compression fixture, 27—compression specimen, 28—lower compression fixture, 29—upper bending fixture support arm, 30—upper bending fixture chuck, 31—bending specimen, 32—lower bending fixture chuck, 33—lower bending fixture support arm, 34—upper shear fixture, 35—loading block, 36—shear specimen, 37—lower shear fixture. DETAILED DESCRIPTION

[0053] The present invention will be further described below through specific embodiments in conjunction with the accompanying drawings.

[0054] Example 1

[0055] An in-situ tensile testing method for ultra-high temperature multi-atmosphere CT induction heating according to this embodiment includes the following steps:

[0056] S1. Build the in-situ loading system for induction heating ultra-high temperature multi-atmosphere CT. First, connect the upper and lower adapters 7 to the load sensor 4 of the mechanical loading tester 1 and the lower servo motor 6, respectively. The effect diagram is as follows: Figure 2 As shown. Figure 3The high temperature furnace 2 shown is placed in the support frame 5 of the mechanical loading tester 1, and the upper and lower adapters 7 are passed through the through holes of the high temperature furnace 2 to fix the high temperature furnace 2. The effect diagram is as follows Figure 1 As shown. Then through Figure 5 The sealing flange 19 shown seals the contact between the through hole of the high temperature furnace 2 and the adapter 7 to ensure the airtightness of the high temperature furnace 2. Then, the induction coil 23, Figure 6 The insulation cotton 24 shown is Figure 7 The heating element 25 is installed in the cavity of the high temperature furnace 2, and the effect diagram is as shown in FIG. Figure 4 shown.

[0057] S2, connect the upper tensile fixture 20 and the lower tensile fixture 22 to the upper load sensor 4 and the lower servo motor 6 through the adapter 7. Then pass the tensile specimen 21 through the heating element 25 and connect it to the upper tensile fixture 20 and the lower tensile fixture 22 respectively, ensuring that the tested part of the tensile specimen 21 is displaced into the heating element. The effect is shown in the figure. Figure 4 shown.

[0058] S3. Adjust the incident height of the X-ray source so that the optical path center of the X-ray is aligned with the centers of the high-temperature furnace cavity X-ray transmission window 17, the tensile specimen 21, and the hatch door X-ray transmission window 9.

[0059] S4. Apply a pre-tightening force to the tensile specimen 21 through the mechanical loading tester 1 to ensure that the tensile specimen 21 is stably connected to the upper tensile fixture 20 and the lower tensile fixture 22.

[0060] S5. Connect the gas channel 16 to a vacuum pump, then start the vacuum pump to evacuate the atmospheric pressure in the high-temperature furnace 2 to below 20 Pa to provide a vacuum environment. Alternatively, connect an external designated gas cylinder (nitrogen, argon, helium, etc.) to the gas channel 19 to introduce the designated gas into the high-temperature furnace 2, thereby creating a specific inert environment and a different oxygen partial pressure environment inside the high-temperature furnace 2.

[0061] S6. Start the cooling system. To enhance the water cooling effect, the high-temperature furnace 2 cooling system is divided into a door cooling system and a cavity cooling system. A water-cooling pipe is connected in series with the door water-cooling inlet 10 and the door water-cooling outlet 11 to form a water-cooling loop, which cools the high-temperature furnace door 8 separately. A water-cooling pipe is connected in series with the high-temperature furnace cavity water-cooling inlet 14 and the high-temperature furnace cavity water-cooling outlet 15 to form a water-cooling loop, which cools the high-temperature furnace cavity 12 separately.

[0062] S7. Install the thermocouple through the thermocouple mounting hole 13. If non-contact temperature measurement is required, an infrared thermometer can also be installed. Aim the infrared thermometer at the tested portion of the tensile specimen 21 through the X-ray transmission window 9 of the cabin door. Start the induction heating power supply. The induction coil 23, insulation 24, and heating element 25 heat and maintain the tensile specimen 21. Measure and calibrate the temperature of the tensile specimen 21 using a thermocouple or infrared temperature measuring device.

[0063] S8. After the tensile specimen 21 is heated and held, the mechanical loading testing machine 1 is started according to the designed loading program to mechanically load the tensile specimen 21. The X-ray source is then turned on to perform a high-temperature in-situ CT scan of the tensile specimen 21 under high temperature and stress conditions until the tensile specimen 21 fractures.

[0064] S9. After the tensile specimen 21 is damaged, the induction heating power supply is turned off, and the test is terminated. When the tensile specimen 21 cools to room temperature, the broken specimen 21 is removed for subsequent characterization and analysis.

[0065] S10, analyzing the load data, temperature data, and CT slices obtained by scanning to obtain damage information and fracture morphology of the tensile specimen 21 under the high-temperature tensile state.

[0066] Example 2

[0067] An in-situ compression testing method for an induction heating ultra-high temperature multi-atmosphere CT of this embodiment includes the following steps:

[0068] S1. Build the in-situ loading system for the induction heating ultra-high temperature multi-atmosphere CT. The building method is the same as that in Example 1.

[0069] S2. Connect the upper compression fixture 26 and the lower compression fixture 28 to the upper load sensor 4 and the lower servo motor 6 via the adapter 7. Then, pass the compression specimen 27 through the heating element 25 and contact the upper compression fixture 26 and the lower compression fixture 28, respectively, ensuring that the tested portion of the compression specimen 27 is located within the heating element.

[0070] S3. Adjust the incident height of the X-ray source so that the center of the X-ray optical path is in a straight line with the centers of the high-temperature furnace cavity X-ray transmission window 17, the compression sample 27 and the cabin door X-ray transmission window 9.

[0071] S4. Apply pre-tightening force to the compression specimen 27 through the mechanical loading tester 1 to ensure that the compression specimen 27 is stably connected to the upper compression fixture 26 and the lower compression fixture 28. The effect is shown in the figure. Figure 9 shown.

[0072] S5. Connect the gas channel 16 to a vacuum pump, then start the vacuum pump to evacuate the atmospheric pressure in the high-temperature furnace 2 to below 20 Pa to provide a vacuum environment. Alternatively, connect an external designated gas cylinder (nitrogen, argon, helium, etc.) to the gas channel 19 to introduce the designated gas into the high-temperature furnace 2, thereby creating a specific inert environment and a different oxygen partial pressure environment inside the high-temperature furnace 2.

[0073] S6. Start the cooling system. To enhance the water cooling effect, the high-temperature furnace 2 cooling system is divided into a door cooling system and a cavity cooling system. A water-cooling pipe is connected in series with the door water-cooling inlet 10 and the door water-cooling outlet 11 to form a water-cooling loop, which cools the high-temperature furnace door 8 separately. A water-cooling pipe is connected in series with the high-temperature furnace cavity water-cooling inlet 14 and the high-temperature furnace cavity water-cooling outlet 15 to form a water-cooling loop, which cools the high-temperature furnace cavity 12 separately.

[0074] S7. Install the thermocouple through the thermocouple mounting hole 13. If non-contact temperature measurement is required, an infrared thermometer can also be installed. Aim the infrared thermometer at the tested portion of the compression specimen 27 through the X-ray transmission window 9 of the cabin door. Start the induction heating power supply. The induction coil 23, insulation 24, and heating element 25 heat and maintain the tensile specimen 21. Measure and calibrate the temperature of the compression specimen 27 using a thermocouple or infrared temperature measuring device.

[0075] S8. After the compression specimen 27 is heated and held, the mechanical loading tester 1 is activated according to the designed loading program to mechanically load the compression specimen 27. The X-ray source is then activated to perform a high-temperature in-situ CT scan of the compression specimen 27 under high temperature and stress conditions until the compression specimen 27 fractures.

[0076] S9. After the compression sample 27 is damaged, the induction heating power supply is turned off, and the test is terminated. When the compression sample 27 cools to room temperature, the fractured sample 27 is removed for subsequent characterization and analysis.

[0077] S10, analyzing the load data, temperature data, and CT slices obtained by scanning to obtain damage information and fracture morphology of the compression sample 27 under high-temperature compression.

[0078] Example 3

[0079] An in-situ bending test method for an induction heating ultra-high temperature multi-atmosphere CT of this embodiment includes the following steps:

[0080] S1. Build the in-situ loading system for the induction heating ultra-high temperature multi-atmosphere CT. The building method is the same as that in Example 1.

[0081] S2, connect the upper bending fixture chuck 30 and the upper bending fixture support arm 29 through pins to form an upper bending fixture, and then connect the lower bending fixture chuck 32 and the lower bending fixture support arm 33 through pins to form a lower bending fixture, as shown in the effect diagram. Figure 10 As shown. The upper and lower bending fixtures are then connected to the upper load sensor 4 and the lower servo motor 6, respectively, via adapters 7. The bending specimen 31 is then passed through the heating element 25 and placed in the slots of the upper and lower bending fixture chucks 30 and 32, completing the specimen installation and ensuring that the tested portion of the bending specimen 31 is located within the heating element.

[0082] S3. Adjust the incident height of the X-ray source so that the optical path center of the X-ray is aligned with the centers of the high-temperature furnace cavity X-ray transmission window 17, the bent sample 31, and the cabin door X-ray transmission window 9.

[0083] S4. Apply pre-tightening force to the bending specimen 31 through the mechanical loading tester 1 to ensure that the bending specimen 31 is stably connected to the upper bending fixture and the lower bending fixture. The effect is shown in the figure. Figure 10 shown.

[0084] S5. Connect the gas channel 16 to a vacuum pump, then start the vacuum pump to evacuate the atmospheric pressure in the high-temperature furnace 2 to below 20 Pa to provide a vacuum environment. Alternatively, connect an external designated gas cylinder (nitrogen, argon, helium, etc.) to the gas channel 19 to introduce the designated gas into the high-temperature furnace 2, thereby creating a specific inert environment and a different oxygen partial pressure environment inside the high-temperature furnace 2.

[0085] S6. Start the cooling system. To enhance the water cooling effect, the high-temperature furnace 2 cooling system is divided into a door cooling system and a cavity cooling system. A water-cooling pipe is connected in series with the door water-cooling inlet 10 and the door water-cooling outlet 11 to form a water-cooling loop, which cools the high-temperature furnace door 8 separately. A water-cooling pipe is connected in series with the high-temperature furnace cavity water-cooling inlet 14 and the high-temperature furnace cavity water-cooling outlet 15 to form a water-cooling loop, which cools the high-temperature furnace cavity 12 separately.

[0086] S7. Install the thermocouple through the thermocouple mounting hole 13. If non-contact temperature measurement is required, an infrared thermometer can also be installed. Aim the infrared thermometer at the tested portion of the curved specimen 31 through the X-ray transmission window 9 of the cabin door. Activate the induction heating power supply. The induction coil 23, insulation 24, and heating element 25 heat and maintain the curved specimen 31. Measure and calibrate the temperature of the curved specimen 31 using a thermocouple or infrared temperature measuring device.

[0087] S8. After the bending specimen 31 is heated and held, the mechanical loading testing machine 1 is started according to the designed loading program to mechanically load the bending specimen 31. The X-ray source is then turned on to perform a high-temperature in-situ CT scan of the bending specimen 31 under high temperature and stress conditions until the bending specimen 31 fractures.

[0088] S9. After the bending sample 31 is damaged, the induction heating power supply is turned off, and the test is terminated. When the bending sample 31 cools to room temperature, the broken sample 31 is taken out for subsequent characterization and analysis.

[0089] S10 , analyzing the load data, temperature data, and CT slices obtained by scanning to obtain damage information and fracture morphology of the bending specimen 31 in a high-temperature bending state.

[0090] Example 4

[0091] An in-situ shear testing method for ultra-high temperature multi-atmosphere CT using induction heating in this embodiment includes the following steps:

[0092] S1. Build the in-situ loading system for the induction heating ultra-high temperature multi-atmosphere CT. The building method is the same as that in Example 1.

[0093] S2. Connect the upper shear fixture 34 and the lower shear fixture 37 to the upper load cell 4 and the lower servo motor 6, respectively, via the adapter 7. Then, pass the shear specimen 36 through the heating element 25 and place it on the lower shear fixture 37. Finally, place the loading block 35 on the shear specimen 36 to complete the specimen installation, ensuring that the tested portion of the shear specimen 36 is located within the heating element.

[0094] S3. Adjust the incident height of the X-ray source so that the center of the X-ray optical path is aligned with the centers of the high-temperature furnace cavity X-ray transmission window 17, the shear sample 36, and the cabin door X-ray transmission window 9.

[0095] S4. Apply pre-tightening force to the shear specimen 36 through the mechanical loading tester 1 to ensure that the shear specimen 36 is stably connected to the upper shear fixture 34 and the lower shear fixture 37. The effect is shown in the figure. Figure 11 shown.

[0096] S5. Connect the gas channel 16 to a vacuum pump, then start the vacuum pump to evacuate the atmospheric pressure in the high-temperature furnace 2 to below 20 Pa to provide a vacuum environment. Alternatively, connect an external designated gas cylinder (nitrogen, argon, helium, etc.) to the gas channel 19 to introduce the designated gas into the high-temperature furnace 2, thereby creating a specific inert environment and a different oxygen partial pressure environment inside the high-temperature furnace 2.

[0097] S6. Start the cooling system. To enhance the water cooling effect, the high-temperature furnace 2 cooling system is divided into a door cooling system and a cavity cooling system. A water-cooling pipe is connected in series with the door water-cooling inlet 10 and the door water-cooling outlet 11 to form a water-cooling loop, which cools the high-temperature furnace door 8 separately. A water-cooling pipe is connected in series with the high-temperature furnace cavity water-cooling inlet 14 and the high-temperature furnace cavity water-cooling outlet 15 to form a water-cooling loop, which cools the high-temperature furnace cavity 12 separately.

[0098] S7. Install the thermocouple through the thermocouple mounting hole 13. If non-contact temperature measurement is required, an infrared thermometer can also be installed. Aim the infrared thermometer at the tested portion of the shear specimen 36 through the X-ray transmission window 9 of the cabin door. Activate the induction heating power supply. The induction coil 23, insulation 24, and heating element 25 heat and maintain the temperature of the shear specimen 36. Measure and calibrate the temperature of the shear specimen 36 using a thermocouple or infrared temperature measuring device.

[0099] S8. After the shear specimen 36 is heated and held, the mechanical loading tester 1 is activated according to the designed loading program to mechanically load the shear specimen 36. The X-ray source is then activated to perform a high-temperature in-situ CT scan of the shear specimen 36 under high temperature and stress conditions until the shear specimen 36 fractures.

[0100] S9. After the shear specimen 36 is damaged, the induction heating power supply is turned off, and the test is terminated. After the shear specimen 36 cools to room temperature, the fractured specimen 36 is removed for subsequent characterization and analysis.

[0101] S10 , analyzing the load data, temperature data, and CT slices obtained by scanning to obtain damage information and fracture morphology of the shear specimen 36 under the high-temperature shear state.

[0102] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. Finally, it should be noted that the purpose of disclosing the embodiments is to facilitate a further understanding of the present invention. However, those skilled in the art will appreciate that various substitutions and modifications are possible without departing from the spirit and scope of the present invention and the appended claims. Therefore, the present invention should not be limited to the contents disclosed in the embodiments, and the scope of protection claimed by the present invention shall be subject to the scope defined in the claims.

Claims

1. An in-situ loading system for an induction heating ultra-high temperature multi-atmosphere CT, characterized by: Includes mechanical loading testing machine, high temperature furnace, fixture unit and cooling system; The high-temperature furnace is placed in the mechanical loading testing machine and fixed by an adapter; the fixture unit is placed inside the high-temperature furnace and fixedly connected to the adapter; there is also a flow channel in the side wall of the high-temperature furnace, and cooling water flows through the flow channel to form a cooling system.

2. The in-situ loading system for induction heating ultra-high temperature multi-atmosphere CT according to claim 1, characterized in that: The mechanical loading testing machine includes an upper servo motor, a load sensor, a support frame and a lower servo motor from top to bottom; the lower servo motor is connected to the support frame, the upper servo motor is connected to the load sensor and coupled to the support frame to form an integral structure, and the servo motor and the upper servo motor are used in conjunction to apply load to the sample and drive the sample to rotate.

3. The in-situ loading system for induction heating ultra-high temperature multi-atmosphere CT according to claim 1, characterized in that: The high-temperature furnace includes a cavity with a flow channel inside and a cabin door; through holes are opened at the top and bottom of the cavity to allow the adapter to extend into the high-temperature furnace to fix the high-temperature furnace; thermocouple mounting holes, gas channels, observation windows and X-ray transmission windows are opened on the side walls of the cavity, and an X-ray transmission window is also opened on the cabin door, and water cooling inlets and outlets are opened on the side walls of the cavity and the cabin door; water enters through the water inlet, flows in the flow channel opened in the side walls of the furnace body, and comes out from the water outlet to form a cooling system; the high-temperature furnace includes an induction coil, thermal insulation cotton and a heating element for heating and keeping the sample warm; three small circular holes with a spacing of 90° and a diameter of 20 mm are distributed in the middle position of the thermal insulation cotton and the heating element for observing the sample and measuring the temperature of the sample.

4. The in-situ loading system for induction heating ultra-high temperature multi-atmosphere CT according to claim 1, characterized in that: The clamp unit includes a tensile clamp, a compression clamp, a bending clamp and a shearing clamp, which can be replaced and used as needed. The tensile fixture is divided into an upper tensile fixture and a lower tensile fixture, which are connected to the top load sensor and the bottom servo motor through adapters respectively, and are used to clamp the tensile specimen; The compression fixture is divided into an upper compression fixture and a lower compression fixture, which are connected to the top load sensor and the bottom servo motor through adapters respectively, and are used to fix the compression specimen; The bending fixture is divided into an upper bending fixture and a lower bending fixture. Both have the same structure and are symmetrically arranged. They are connected to the top load sensor and the bottom servo motor through adapters, respectively, to clamp the bending specimen. The bending fixture consists of a support arm and a chuck, which are movably connected by a pin. When a load is applied to the support arm, the pin rotates, driving the chuck to rotate, realizing the bending of the specimen. The shear fixture is divided into an upper shear fixture, a loading block and a lower shear fixture. The upper shear fixture and the lower shear fixture are connected to the top load sensor and the bottom servo motor respectively through adapters; the lower shear fixture and the loading block fix the specimen through four anti-symmetrical support planes. When a load is applied to the upper shear fixture, the load is transferred to the loading block. Under the joint action of the loading block and the lower shear fixture, an anti-symmetric four-point bending load is formed, which will generate shear force at the center of the shear specimen to achieve shearing of the specimen.

5. The in-situ loading system for induction heating ultra-high temperature multi-atmosphere CT according to claim 1, characterized in that: The thickness of the X-ray transmission window is between 50 μm and 300 μm, and the diameter of the X-ray transmission window is 20 mm; the material of the X-ray transmission window can be replaced with aluminum alloy, boron nitride or quartz glass according to different usage functions.

6. An in-situ loading method for an induction-heated ultra-high temperature multi-atmosphere CT, implemented based on the in-situ loading system for an induction-heated ultra-high temperature multi-atmosphere CT according to claim 1, 2, 3, 4, or 5, characterized in that: The following steps are involved: S1. Build the in-situ loading system for the induction heating ultra-high temperature multi-atmosphere CT; S2. Connect the fixture to the load cell at the upper end and the lower servo motor at the lower end through the adapter, then place the sample in the heating element and connect the sample to the fixture to ensure that the tested part of the sample is located in the heating element; S3. Adjust the incident height of the X-ray source so that the center of the sample is located on the optical path of the X-ray; S4. Apply preload force to the specimen using a mechanical loading tester to ensure a stable connection between the specimen and the fixture. S5. Connect the gas channel to a vacuum pump to extract vacuum, or directly introduce specified gas to form a vacuum environment, an inert environment, and different oxygen partial pressure environments in the high-temperature furnace; S6. Turn on the cooling system to allow cooling water to flow through the water cooling channel of the high-temperature furnace to cool the furnace body; S7. Install a thermocouple or infrared temperature measuring device, heat and keep the sample warm using an induction heating device, and measure and calibrate the temperature of the sample using the thermocouple or infrared temperature measuring device; S8. Conduct high temperature in-situ testing; S9, end the test; S10. Experimental data analysis.

7. The method according to claim 6, wherein: The inert gas in step S5 is nitrogen, argon or helium.

8. The method according to claim 6, wherein: In step S7, the heating temperature in a vacuum or inert environment is not less than 2200° C., and the heating temperature in the atmosphere or an environment with different oxygen partial pressures is not less than 1800° C.

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