Device and method for testing high-temperature creep of alumina fiber under controllable atmosphere

Abstract

The invention relates to the field of physical and chemical preparation, and relates to alumina fiber high-temperature creep test equipment and a test method under a controllable atmosphere. The testing equipment comprises a fiber clamping device, a furnace tube, a furnace body, a steering wheel, a temperature control system, a fiber loading device and at least two groups of displacement sensors, at least one group of displacement sensors is arranged under the loading device, and the detection direction of the displacement sensors is parallel to the alumina fiber connected to the loading device; and at least one group of displacement sensors is arranged above the fiber loading device, and the detection direction of the displacement sensors is vertical to the alumina fiber connected to the loading device. According to the invention, the horizontally laid ceramic fiber paper is matched with the tubular furnace, and the experiment precision is improved through the application of the steering wheel and the bidirectional displacement sensor (in the horizontal direction and the vertical direction). The device is reasonable in design, convenient to use, high in obtained data precision and convenient to apply.

Description

Technical Field

[0001] The invention relates to the field of physical and chemical preparation, and relates to a novel device for testing the high-temperature creep performance of a material, and in particular to a high-temperature creep testing device and a testing method for alumina fiber in a controlled atmosphere. Background Art

[0002] As a new type of strategic material, alumina fiber has a wide range of applications in aerospace, national defense and military industries due to its excellent mechanical properties and high-temperature oxidation resistance.

[0003] High temperature creep test is a high temperature mechanical property test of materials, which is used to test the process of slow deformation of materials under the action of high temperature and constant temperature and stress for a long time. High temperature creep performance is also an important indicator of constant alumina ceramic fiber materials. The current high temperature creep test equipment has a relatively simple structure and a low degree of automation, and basically tests metal bars, blocks and tubular materials. No high temperature creep equipment for filamentary materials such as alumina fibers has been found. The high temperature creep test of alumina fiber ceramics is a micron-level wire, and there are obvious technical barriers to using high temperature creep test equipment of other materials for testing. It requires a series of requirements such as a suitable clamping device and a precise displacement measuring instrument. At the same time, the current test methods use simple and inaccurate loading methods, box furnaces to provide heating environments, etc. These methods cannot truly reflect the high temperature creep behavior of fiber bundles, and the actual application rate is relatively low. At the same time, they are not suitable for high temperature creep tests of alumina fiber materials with high precision requirements. As pointed out in application number 202211621668.9, a measuring device and method for the high temperature creep of a metal material adopts a vertical type. At the same time, this patent does not involve improvements to the clamping device and clamping method, and it does not involve monitoring of horizontal (or lateral) displacement, so its test accuracy needs to be further improved.

[0004] In order to effectively measure the high-temperature creep performance of alumina fiber, the present invention improves the tightening method so that the fiber can be effectively installed on the equipment, and adds sensors in different positions to obtain more accurate deformation. At the same time, for the current low degree of automation, the present invention provides a data processing system, which can not only collect data in real time, but also obtain corresponding results according to the set calculation formula, and obtain high-temperature creep curves, relaxation curves and other high-temperature creep performance indicators of the material. Summary of the invention

[0005] In view of the above technical problems, the present invention provides a high temperature creep test method for alumina fiber, and optimizes and simplifies the measurement and calculation of strain. The relevant formula of the test principle is: ; ; ; ; ; in: 2L represents the initial total length of the fiber between -L and L, starting from the center of the fiber bundle specimen (the highest temperature area); (2L)e represents the effective creep length of the fiber between -L and L starting from the center of the fiber bundle specimen; Indicates the elongation of the fiber bundle sample (the elongation caused by high temperature creep, when the temperature rises to the set temperature and creep begins, it is the starting point of measurement); and They represent the measured total strain, the measured total strain rate, the specimen center strain, the specimen center strain rate, and the steady-state creep rate, respectively; Q represents the creep activation energy; R is the gas constant; σ is stress; T is the furnace temperature; T( l ) The temperature at a certain point in the furnace; T L is the temperature of the point L in the furnace at a distance from the center point; T0 is the temperature of the highest point in the furnace (center point temperature).

[0006] The size of L is selected according to one's own experimental needs. Different samples have different L values, which is related to the characteristics of the material itself. The 2L value needs to be smaller than the length of the furnace tube. Due to the different effective temperature zone lengths of the heating tube furnace, try to select the effective temperature zone length range of the furnace.

[0007] The technical solution of the present invention is as follows: The present invention discloses a high temperature creep test equipment for alumina fibers in a controlled atmosphere; the equipment comprises a fiber clamping device 2, a furnace tube 4, a furnace body 5, a steering wheel 6, a temperature control system 7, a fiber loading device 8, and at least two sets of displacement sensors 9. The fiber clamping device 2 and the steering wheel 6 are arranged outside the furnace tube 4 and are respectively located at two ends of the furnace tube 4; During operation, ceramic fiber paper is laid on the chuck of the fiber clamping device 2, and the chuck clamps one end of the alumina fiber by laying the ceramic fiber paper. The alumina fiber passes through the furnace tube 4 and the steering wheel 6 in sequence, and the other end of the alumina fiber is connected to the alumina fiber loading device 8. At least one group of displacement sensors 9 is arranged directly below the loading device 8, and its detection direction is parallel to the alumina fiber connected to the loading device 8; at the same time, at least one group of displacement sensors 9 is arranged above the fiber loading device 8, and its detection direction is perpendicular to the alumina fiber connected to the loading device 8.

[0008] In the present invention, the fiber clamping device 2 is placed horizontally, and the ceramic fiber paper laid on the clamping head is laid horizontally. This design can reduce the shear force on the fiber to a minimum.

[0009] In the present invention, the fiber clamping device 2 cooperates with the ceramic fiber paper to clamp the fiber, and the fiber is placed on the rough ceramic fiber paper surface for clamping. This design can concentrate stress, avoid uneven force on the fiber, increase friction, and prevent the stressed fiber from falling off.

[0010] In the present invention, at least one group of displacement sensors 9 is arranged above the loading device 8, and its detection direction is perpendicular to the alumina fiber connected to the loading device 8. The displacement sensor arranged at this position can check whether the displacement occurs during the creep process, and at the same time, in order to avoid the fiber bundle from contacting the furnace tube during the creep process, resulting in experimental errors; the displacement sensor in the vertical direction is used to measure the elongation of the fiber bundle during the creep process, because the high-temperature creep experiment of alumina fiber has high accuracy requirements. The sensor used in the present invention has high accuracy (the preferred sensor is a small-range and accurate pen-type sensor (LVDT), whose model is Marposs U10, with a measuring stroke of ±0.1mm and an accuracy range of 0.1μm-0.5μm), and the horizontal and vertical directions are mutually calibrated, which further improves the accuracy.

[0011] In actual application, at one end of the furnace body 5 close to the steering wheel 6, an actual or virtual reference cross coordinate system is made on the furnace body 5 and / or the cross section of the furnace tube 4 with the anchor point of the center of the cross section of the furnace tube 4. The minimum scale of the coordinate system is 0.1 micron. This reference system is mainly used to cooperate with the displacement sensor 9 arranged above the loading device 8 and whose detection direction is perpendicular to the alumina fiber connected to the loading device 8, so as to further improve its accuracy in measuring whether there is horizontal displacement.

[0012] The present invention discloses a high temperature creep test equipment for alumina fiber under a controlled atmosphere; the furnace body 5 is a dual temperature zone furnace body. When a single temperature zone is distributed in the furnace tube area, there will be errors in each part. The dual temperature zone furnace body can be used to make the temperature distribution of the alumina fiber more uniform during the high temperature creep process. At the same time, the dual temperature zone furnace body adopts an advanced descending system, which can achieve precise temperature control, and the temperature control accuracy can reach ±1°C, and has the function of stepless adjustment from low power to high power, which is conducive to temperature control during the high temperature creep process and reduces experimental errors.

[0013] The present invention preferably uses a tubular furnace, which uses radiation heating. Heat is transferred around the furnace tube, making the heat transfer more uniform and less prone to local overheating. Box-type furnaces may use radiation heating or convection heating, and the temperature uniformity in the furnace is relatively poor. At the same time, the present invention utilizes the characteristics of the tubular furnace, adds sealed furnace covers at both ends of the furnace tube, and adjusts the atmosphere and pressure inside the furnace tube by connecting an external gas, thereby better restoring the actual use scenario of the alumina fiber, and the data is more accurate and more effective.

[0014] The preferred loading device of the present invention is equipped with a force sensor to monitor the change of force during the experiment, determine whether the force is correct by observation, and adjust the force to keep the force on the fiber constant. It is used to check the accuracy of the force, ensure the constancy and accuracy of the loading force during the experiment, reduce experimental errors, and is suitable for materials with high precision requirements such as alumina fibers.

[0015] The present invention provides a testing method for alumina fiber high temperature creep testing equipment under a controlled atmosphere, comprising the following steps: Step 1 Prepare ceramic fiber paper with a size matching that of the clamp in the fiber clamping device 2; Step 2 The alumina fiber bundle is treated with a solvent; after the solvent evaporates, the two ends of the fiber bundle are horizontally aligned and bonded to the center of two pieces of ceramic fiber paper using a binder, and the rough surface of the ceramic fiber paper contacts the fiber.

[0016] Step 3 The ceramic fiber paper sheet with alumina fiber is folded along the center line to ensure that the fiber bundle is kept in the middle part of the folded fiber paper to prevent the fiber from falling off and being damaged due to uneven force. Then it is installed on the chuck of the fiber clamping device 2; the chuck clamps one end of the alumina fiber by laying the ceramic fiber paper, and the alumina fiber passes through the furnace tube 4 and the steering wheel 6 in turn. The other end of the alumina fiber is connected to the alumina fiber loading device 8. At least one group of displacement sensors 9 is arranged directly below the carrier 8, and its detection direction is parallel to the alumina fiber connected to the loading device 8. The displacement sensor arranged at this position is defined as A; at least one group of displacement sensors 9 is arranged above the carrier 8, and its detection direction is perpendicular to the alumina fiber connected to the loading device 8. The displacement sensor arranged at this position is defined as B; a digital controller is used for input signal generation and data acquisition; A collects vertical displacement data, which represents the deformation of the fiber bundle during creep. B collects the fiber displacement deviation in the horizontal direction, and establishes a reference system on the left furnace wall through the set reference system (with the center of the furnace tube as the midpoint, as shown in the attached Figure 2 As shown in the figure, at the beginning of the experiment, the fiber is placed in the center of the furnace tube by adjusting the height of the pulley to coincide with the center line. After the experiment starts, the data of the horizontal displacement sensor is used to feedback whether the fiber bundle in the furnace has displacement deviation in the horizontal and vertical directions to ensure that it is not affected by other forces, such as shear force, so as to ensure the high accuracy of the experiment. When the displacement in the x-axis direction and the y-axis direction in the furnace exceeds the creep elongation When the error is less than 10%, the experimental results will be considered invalid and the high accuracy of the experiment cannot be guaranteed.

[0017] Step 4 Turn on the heating furnace and heat the furnace body. When the temperature reaches the specified temperature, collect the temperature data in the furnace, determine the temperature distribution inside the furnace body, obtain the creep temperature length, determine 2L through the selected temperature measurement range, and then use formula (4) to substitute the temperature value to obtain the ratio of the measured total strain rate and the center strain rate of the sample. Substitute the first two into formula (5) to obtain (2L) e Creep effective length.

[0018] Step 5 The alumina fiber is loaded with force by the loading device 8, and the accuracy of the force is checked by the sensor, that is, the force loaded by the loading device is compared with the reading of the sensor on the device. At the same time, the change of force in the whole process is monitored, and the loading device is adjusted to keep the force constant through feedback; after the set heat treatment time, the data of sensors A and B are collected to obtain the creep elongation of the sample And the displacement deviation of the fiber bundle in the furnace.

[0019] Step 6 Then the creep elongation obtained is and effective creep length (2L) e Substitute it into formula (2) to obtain the center strain of the specimen , the creep elongation obtained and the total initial creep length 2L are substituted into formula (1) to obtain the total measured strain of the specimen. .

[0020] The present invention provides a testing method for alumina fiber high temperature creep testing equipment under a controlled atmosphere. When used in industry, several alumina ceramic tubes with end covers suitable for the double-zone furnace are customized and fixed at the center of the double-zone furnace, which is beneficial to the uniformity and repeatability of the temperature distribution at the high-temperature center of the fiber bundle.

[0021] In step 4, a dual-zone furnace with a heating assembly and three symmetrically designed controlled thermocouples provides a high temperature environment and feeds back to a temperature controller, where three thermocouples measure the temperature distribution of the entire furnace.

[0022] When applied in industry, the atmosphere can also be selected. For example, pores are provided at both ends of the furnace tube 4 to control the atmosphere. More importantly, the present invention can also be used for some special reactions in the creep process.

[0023] The highest point where the alumina fiber contacts the steering wheel 6 is located on the same horizontal plane as the ceramic fiber paper. This design can effectively reduce stress in other directions and improve the accuracy of the test.

[0024] The present invention can adjust the atmosphere and pressure in the furnace during high-temperature sintering by introducing atmosphere through the end covers at both ends.

[0025] The beneficial effects of the present invention are: The testing equipment and process of the present invention are more intelligent, accurate and reliable, and have wider applications.

[0026] Compared with existing test methods, such as fiber pull creep test device, PE-UHMW fiber tensile creep performance test method, etc., a small-range and precise electronic tensile test system and pen-type displacement sensor intelligent assembly are used, and the measurement results are more accurate, effective and intelligent. At the same time, a displacement sensor is added in the horizontal direction to facilitate the verification of its horizontal translation, prevent offset, and improve the experimental accuracy.

[0027] The present invention assembles ceramic tubes in a double-zone furnace to effectively balance the temperature distribution of the fiber bundle at the high-temperature center, making it easier to control the temperature. At the same time, the present invention optimizes and simplifies the measurement and calculation of strain, which is more conducive to scientific research promotion and industrialization compared with other processes.

[0028] The present invention can ensure the constancy of force during the creep experiment, which is beneficial to improving the accuracy of the experiment.

[0029] The invention fills the gap in equipment for testing high-temperature creep of alumina fibers, and develops a high-precision alumina fiber creep testing method that matches the equipment.

[0030] The invention can pass the atmosphere and control the atmosphere and pressure during the high temperature creep test. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 Figure 1. Alumina fiber high temperature creep test equipment under controlled atmosphere; Figure 2 Schematic diagram of the reference system of the horizontal direction sensor; Figure 3 The device developed for the present invention is not equipped with a displacement sensor and is a physical picture of the device when loaded.

[0032] Figure 2 In the figure, 1 is a data processing system, 2 is a fiber clamping device, 3 is an alumina fiber, 4 is a furnace tube (4 has a sealing end cover), 5 is a high-temperature heating furnace body, 6 is a roller, 7 is a temperature control system, 8 is a fiber loading device, and 9 is a displacement sensor, which is composed of 9-1 and 9-2. DETAILED DESCRIPTION

[0033] The high temperature creep test equipment of alumina fiber under controlled atmosphere used in the embodiment of the present invention comprises a fiber clamping device 2, a furnace tube 4, a furnace body 5, a steering wheel 6, a temperature control system 7, a fiber loading device 8, and at least two sets of displacement sensors 9. The fiber clamping device 2 and the steering wheel 6 are arranged outside the furnace tube 4. During operation, ceramic fiber paper is laid on the chuck of the fiber clamping device 2, and the chuck clamps one end of the alumina fiber by laying the ceramic fiber paper. The alumina fiber passes through the furnace tube 4 and the steering wheel 6 in sequence, and the other end of the alumina fiber is connected to the alumina fiber loading device 8. The displacement sensor 9 is divided into two groups (one group is 9-1 and the other group is 9-2), one of which is 9-1 and is arranged directly below the loading device 8, and its detection direction is parallel to the alumina fiber connected to the loading device 8; at the same time, the other group 9-2 of the displacement sensor 9 is arranged above the fiber loading device 8, and its detection direction is perpendicular to the alumina fiber connected to the loading device 8.

[0034] The fiber clamping device 2 is placed horizontally, and the ceramic fiber paper is laid horizontally on the clamping head.

[0035] The fiber clamping device 2 cooperates with the ceramic fiber paper to clamp the fibers, and the fibers are placed on the rough surface of the ceramic fiber paper for clamping.

[0036] The displacement sensor 9 is divided into two groups. One group is arranged above the loading device 8, and its detection direction is perpendicular to the alumina fiber connected to the loading device 8. The displacement sensor arranged at this position can check whether there is displacement during the creep process, and at the same time, in order to avoid the fiber bundle from contacting the furnace tube during the creep process, resulting in experimental errors; the vertical displacement sensor is used to measure the elongation of the fiber bundle during the creep process, because the high-temperature creep experiment of alumina fiber requires high accuracy. At the same time, at one end of the furnace body 5 close to the steering wheel 6, a virtual reference cross coordinate system is made on the cross section of the furnace body 5 and the furnace tube 4 with the anchor point of the center of the cross section of the furnace tube 4. The minimum scale of the coordinate system is 0.1 micron. This reference system is mainly used to cooperate with the displacement sensor 9-2, which can further improve its accuracy in measuring whether there is horizontal displacement.

[0037] The sensor used is a small-range and accurate pen-type sensor (LVDT), model Marposs U10, with a measuring stroke of ±0.1mm and an accuracy range of 0.1μm-0.5μm. The furnace body 5 is a dual-temperature zone tubular furnace.

[0038] Comparative Example 1 (1) Prepare some 3cm x 3cm pieces of ordinary printing paper (all smooth) (3cm is to fit the size of the clamping tool) (2) Use anhydrous ethanol to bundle a bundle of fibers into a fiber bundle test sample with a length of about 85 cm. After the ethanol evaporates, use an adhesive such as epoxy resin or glue to horizontally align the two ends of the fiber bundle and bond them to the center of two pieces of printing paper.

[0039] (3) The paper sheet with alumina fiber is mounted on the clamping head of the fiber clamping device 2; the alumina fiber passes through the furnace tube 4 and the steering wheel 6 in sequence, and the other end of the alumina fiber is connected to the alumina fiber loading device 8. One group of displacement sensors 9 is arranged directly below the loading device 8, and its detection direction is parallel to the alumina fiber connected to the loading device 8. The displacement sensor arranged at this position is defined as A; a digital controller is used to generate input signals and collect data; A collects vertical displacement data, which represents the deformation amount of the fiber bundle during the creep process. ; (4) The furnace body is heated up and set to 1200°C. After the temperature stabilizes, the temperature is checked to determine the central temperature area 2L=10cm. The alumina fiber is loaded with force through the loading device 8, and the accuracy of the force is checked through the sensor, that is, the force loaded by the loading device is compared with the sensor reading on the device. At the same time, the force changes during the whole process are monitored, and the force is kept constant by adjusting the loading device; after the set heat treatment time, the creep elongation of the sample is obtained by collecting sensor A. At the same time, after the temperature is stabilized, the temperature is collected, and then the temperature is substituted into formula (4) to obtain the temperature value to obtain the ratio of the measured total strain rate and the center strain rate of the specimen, and then 2L is substituted into formula (5) to obtain the effective creep length (2L) e A digital controller is used for input signal generation and data acquisition; the input creep stress of the fiber loading device is preset to be 100 MPa, and the stress magnitude is verified by feedback readings from the force sensor on the loading device.

[0040] (5) After the fiber is subjected to high temperature insulation treatment for a long time, the fiber creeps. The displacement sensor installed in the vertical direction is coaxial with the fiber to measure the elongation. It is 0.006mm, and the fiber undergoes creep rupture during the test.

[0041] (6) Calculate the effective high temperature creep measurement length (2L) of the fiber bundle based on the various parameters measured. e is about 5.6 mm, and then the creep elongation and effective creep length (2L) e Substitute it into formula (2) to obtain the center strain of the specimen , the creep elongation obtained and the total initial creep length 2L are substituted into formula (1) to obtain the total measured strain of the specimen. .

[0042] The central strain of the fiber is calculated from equations (2) and (3) based on the elongation of the fiber bundle measured by the pen-type displacement sensor: About 0.01%, and steady-state creep rate About 3.13×10 -9 .

[0043] The data obtained from Example 2, the center strain About 0.01%, and steady-state creep rate About 3.13×10 -9， It is far smaller than the publicly reported data of fiber, the deviation is too large, and the measurement results do not conform to the actual situation.

[0044] Example 1 By considering the problems arising in the above comparative examples, corresponding measures are taken in the following embodiments to correct the corresponding problems and improve the effectiveness and accuracy of the experimental tests.

[0045] (1) Prepare some ceramic fiber papers of 3 cm x 3 cm size (3 cm is to fit the size of the clamping tool chuck) (2) Use anhydrous ethanol to bundle a bundle of fibers into a fiber bundle test sample with a length of about 85 cm. After the ethanol evaporates, use an adhesive such as epoxy resin or glue to horizontally align the two ends of the fiber bundle and bond them to the center of two pieces of ceramic fiber paper, using the rough surface to contact the fibers.

[0046] (3) Fold the ceramic fiber paper with alumina fiber in accordance with the center line to ensure that the fiber bundle remains in the middle of the folded fiber paper to prevent uneven force on the fiber from falling off and being damaged. Then install it on the chuck of the fiber clamping device 2; the chuck clamps one end of the alumina fiber by laying the ceramic fiber paper, and the alumina fiber passes through the furnace tube 4 and the steering wheel 6 in turn. The other end of the alumina fiber is connected to the alumina fiber loading device 8. One of the two groups of displacement sensors 9 is set directly below the loading device 8, and its detection direction is parallel to the alumina fiber connected to the loading device 8. The displacement sensor arranged at this position is defined as A, that is, Figure 1 9-1 in the figure; one of the two groups of displacement sensors 9 is arranged above the loading device 8, and its detection direction is perpendicular to the alumina fiber connected to the loading device 8. The displacement sensor arranged at this position is defined as B, that is, Figure 1 9-2 in the figure; a digital controller is used to generate input signals and collect data; A collects vertical displacement data, which represents the deformation of the fiber bundle during creep. B collects the fiber displacement deviation in the horizontal direction, determines the position of the aligned fiber bundle, and on the premise of determining the reference system, uses the data from the horizontal displacement sensor to feedback whether the fiber bundle in the furnace has horizontal displacement in the left-right direction or in the up-down direction, to ensure that it is not affected by other forces.

[0047] (4) The furnace body is heated up and set to 1200°C. After the temperature stabilizes, the temperature is calibrated to determine the central temperature area 2L (L=5cm). The alumina fiber is loaded with force through the loading device 8, and the accuracy of the force is calibrated through the sensor, that is, the force loaded by the loading device is compared with the sensor reading on the device. At the same time, the force changes during the whole process are monitored, and the force is kept constant by adjusting the loading device; after the set heat treatment time, the data of sensors A and B are collected to obtain the creep elongation of the sample And X, Y displacement. At the same time, after the temperature is stabilized, the temperature is collected, and then the temperature is substituted into formula (4) to obtain the temperature value to obtain the ratio of the measured total strain rate and the center strain rate of the specimen, and then 2L is substituted into formula (5) to obtain the effective creep length (2L) e A digital controller is used for input signal generation and data acquisition. The input creep stress of the fiber loading device is preset to be 100 MPa, and the stress is then calibrated by feedback from the force sensor on the loading device.

[0048] (5) After the fiber is subjected to high temperature insulation treatment for a long time, the fiber creeps. The displacement sensor installed in the vertical direction is coaxial with the fiber to measure the elongation. About 0.11mm.

[0049] (6) Calculate the effective high temperature creep measurement length (2L) of the fiber bundle based on the various parameters measured. e is about 5.3cm, and then the creep elongation and effective creep length (2L) e Substitute it into formula (2) to obtain the center strain of the specimen , the creep elongation obtained and the total initial creep length 2L are substituted into formula (1) to obtain the total measured strain of the specimen. .

[0050] The central strain of the fiber is calculated from equations (2) and (3) based on the elongation of the fiber bundle measured by the pen-type displacement sensor: is about 0.21%, and the steady-state creep rate About 1.13×10 -6 .

[0051] The results obtained in this example are close to the creep properties reported for the fibers, which proves the validity and accuracy of this test method, and also proves the practicality of this test method.

Claims

1. A high temperature creep test equipment for alumina fiber under controlled atmosphere; characterized by: The invention comprises a fiber clamping device (2), a furnace tube (4), a furnace body (5), a steering wheel (6), a temperature control system (7), a fiber loading device (8), and at least two sets of displacement sensors (9). The fiber clamping device (2) and the steering wheel (6) are arranged outside the furnace tube (4) and are respectively located at two ends of the furnace tube (4); During operation, ceramic fiber paper is laid on the clamping head of the fiber clamping device 2, and the clamping head clamps one end of the alumina fiber by laying the ceramic fiber paper. The alumina fiber passes through the furnace tube (4) and the steering wheel (6) in sequence, and the other end of the alumina fiber is connected to the alumina fiber loading device (8). At least one group of displacement sensors (9) is arranged directly below the loading device (8), and its detection direction is parallel to the alumina fiber connected to the loading device (8); at the same time, at least one group of displacement sensors 9 is arranged above the fiber loading device (8), and its detection direction is perpendicular to the alumina fiber connected to the loading device (8).

2. The high temperature creep test equipment for alumina fiber in a controlled atmosphere according to claim 1; characterized in that: The fiber clamping device (2) is placed horizontally, and the ceramic fiber paper is laid horizontally on the clamping head.

3. The high temperature creep test equipment for alumina fiber in controlled atmosphere according to claim 2; characterized in that: The fiber clamping device (2) cooperates with the ceramic fiber paper to clamp the fibers, and the fibers are placed on the rough surface of the ceramic fiber paper for clamping.

4. The high temperature creep test equipment for alumina fiber in a controlled atmosphere according to claim 1; characterized in that: The displacement sensor (9) is a pen-type sensor with a measuring stroke of ±0.1 mm and an accuracy range of 0.1 μm-0.5 μm.

5. The high temperature creep test equipment for alumina fiber in controlled atmosphere according to claim 1, characterized in that: The furnace body (5) is a dual-temperature zone furnace body, and its temperature control accuracy is ±1°C.

6. The high temperature creep test equipment for alumina fiber in controlled atmosphere according to claim 1; characterized in that: Tube furnace, the tube furnace adopts radiation heating method.

7. A method for testing the alumina fiber high temperature creep test equipment under controlled atmosphere according to any one of claims 1 to 6, characterized in that: The steps include: Step 1 Prepare ceramic fiber paper with a size matching that of the clamp in the fiber clamping device (2); Step 2 The alumina fiber bundle is treated with a solvent; after the solvent evaporates, the two ends of the fiber bundle are horizontally aligned and bonded to the center of two pieces of ceramic fiber paper using a binder, and the rough surface of the ceramic fiber paper contacts the fiber; Step 3 Fold the ceramic fiber paper with alumina fibers in accordance with the center line to ensure that the fiber bundles remain in the middle of the folded fiber paper to prevent uneven force on the fibers from falling off and being damaged. The fiber clamping device (2) is then mounted on the clamping head of the fiber clamping device (2); the clamping head clamps one end of the alumina fiber by laying ceramic fiber paper, and the alumina fiber passes through the furnace tube (4) and the steering wheel (6) in sequence. The other end of the alumina fiber is connected to the alumina fiber loading device (8). At least one group of displacement sensors (9) is arranged directly below the loading device (8), and its detection direction is parallel to the alumina fiber connected to the loading device (8). The displacement sensor arranged at this position is defined as A; vertical displacement data is collected, and this data represents the deformation amount of the fiber bundle during the creep process. ; A digital controller is used to generate input signals and collect data. At least one group of displacement sensors 9 is arranged above the loading device (8), and its detection direction is perpendicular to the alumina fiber connected to the loading device (8). The displacement sensor arranged at this position is defined as B. The fiber displacement deviation in the horizontal direction is collected, and the data of the horizontal displacement sensor is used to feedback whether the fiber bundle has been displaced in the horizontal direction, so as to ensure that it is not affected by other forces. Step 4 Turn on the heating furnace and heat the furnace body. When the temperature reaches the specified temperature, collect the temperature data in the furnace, determine the temperature distribution inside the furnace body, obtain the creep temperature interval length, determine 2L through the selected temperature measurement interval, and then use formula (4) to substitute the temperature value to obtain the ratio of the measured total strain rate and the center strain rate of the sample; Substitute the first two into formula (5) to obtain (2L) e Length of effective creep temperature interval; Step 5 The alumina fiber is loaded with force by the loading device 8, and the accuracy of the force is checked by the sensor, that is, the force loaded by the loading device is compared with the reading of the sensor on the device. At the same time, the change of force in the whole process is monitored, and the loading device is adjusted to keep the force constant through feedback; after the set heat treatment time, the data of sensors A and B are collected to obtain the creep elongation of the sample and horizontal displacement; Step 6 Then the creep elongation obtained is and effective creep length (2L) e Substitute it into formula (2) to obtain the center strain of the specimen , the creep elongation obtained and the total initial creep length 2L are substituted into formula (1) to obtain the total measured strain of the specimen. .

8. The testing method of the alumina fiber high temperature creep testing equipment under controlled atmosphere as claimed in claim 7, characterized in that: The highest position where the alumina fiber contacts the steering wheel (6) is located at the same level as the ceramic fiber paper.

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