Tool clamp for axially stretching sample and working method
By using adapters and pins made of ceramic materials, combined with a heating constant temperature box and a tensile testing machine, the problem of inaccurate testing of traditional metal fixtures at high temperatures is solved, and the accurate testing of axial tensile performance at high temperatures is achieved, and the reliability and repeatability of test results are improved.
Patent Information
- Application Number
- CN202510562927.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-30
- Publication Date
- 2025-07-18
AI Technical Summary
When traditional metal fixtures undergo axial tensile tests under high temperature and ultra-high temperature environments, there are problems such as recrystallization and hole deformation, which affects the accuracy of the test results. The design of ceramic fixtures faces challenges in high temperature stability and clamping reliability.
Adapters and pins made of ceramic materials are designed as high-temperature resistant tooling fixtures, combined with a heating constant temperature box and tensile testing machine to ensure stable connections and conduct axial tensile testing at high temperatures. The smooth transition mechanism reduces stress concentration, and the modular design is easy to install and replace.
Accurate axial tensile performance testing at temperatures above 1000℃ is achieved, which improves the accuracy and reliability of test results, avoids high-temperature damage, meets the strength requirements of metal matrix material samples, and ensures the accuracy and repeatability of test results.
Smart Images
Figure CN120333978A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of mechanical testing, and specifically relates to a fixture and working method for an axially tensile sample. Background Art
[0002] In recent years, with the increasing demand for high-temperature materials in the fields of aerospace, energy, and power, the requirements for material testing technology and testing accuracy have gradually increased. Axial tensile testing is one of the key methods for evaluating the tensile properties of materials. When traditional metal fixtures are used for tensile testing in high-temperature and ultra-high-temperature (usually exceeding 1000 °C or even higher) environments, problems such as recrystallization and pore deformation are likely to occur due to limitations in the melting point of their own materials, high-temperature oxidation, and mismatch in the thermal expansion coefficients with the test materials, which affect the accuracy of test results.
[0003] As a fixture material, ceramic materials have excellent properties such as high specific strength, high specific modulus, high reliability, high temperature resistance, ablation resistance, and low density, and have the potential to replace metals and their alloys as a new generation of high-temperature structural materials. Compared with superalloy materials, ceramic matrix composites have a lower density (about 30% of nickel-based superalloys), better high-temperature resistance (exceeding 1200 °C), and a lower thermal expansion coefficient. However, the design and manufacture of ceramic fixtures also face many challenges, such as stability at high temperatures and reliability in clamping specimens. Therefore, there is an urgent need to develop a special fixture and operation method suitable for axial tensile testing at temperatures exceeding 1000 °C. Summary of the Invention
[0004] In view of the problems in the background art, the present invention provides a fixture for an axially tensile sample. The technical solution includes: a circular cross-section specimen, two first adapters, two first pins, a heating and constant-temperature box, and a tensile testing machine. The tensile testing machine includes an upper connecting rod and a lower connecting rod of the tensile testing machine. It is characterized in that it further includes: two ceramic adapters and two ceramic pins. The upper connecting rod and the lower connecting rod of the tensile testing machine are both threadedly connected to the stud portion of a first adapter through threads. The second pin connection cylindrical portions of the two ceramic adapters are respectively inserted into the first pin connection cylindrical portions of a first adapter, and the first pin connection cylindrical portions are connected to the second pin connection cylindrical portions through a first pin.
[0005] The circular cross-section specimen includes: the upper connector on the circular cross-section specimen, the circular cross-section test part, and the lower connector on the circular cross-section specimen. The upper connector and the lower connector on the circular cross-section specimen are respectively inserted into the second pin connection cylindrical parts of a ceramic adapter. The second pin connection cylindrical part of the upper ceramic adapter is connected to the upper connector of the circular cross-section specimen through a ceramic pin, and the second pin connection cylindrical part of the lower ceramic adapter is connected to the lower connector of the circular cross-section specimen through another first pin.
[0006] The two ceramic adapters, the two ceramic pins, and the circular cross-section specimen are located in a heating and constant temperature box.
[0007] The axes of the circular cross-section specimen, the two first adapters, and the two ceramic adapters are collinear. The projections of the axes of the first pins and the ceramic pins on the reference plane are perpendicular and perpendicularly pass through the axis of the circular cross-section specimen. The reference plane is perpendicular to the axis of the circular cross-section specimen.
[0008] The axes of the two first pins are parallel, and the axes of the two ceramic pins are parallel.
[0009] The ceramic adapter includes: a second pin connection cylindrical part, a second cylindrical solid part, and a second pin connection cylindrical part. The second pin connection cylindrical part and the second pin connection cylindrical part are respectively integrally fixed to one end face of the second cylindrical solid part. The axes of the second pin connection cylindrical part, the second cylindrical solid part, and the second pin connection cylindrical part are collinear.
[0010] A first pin inner installation through hole passing through the axis of the second pin connection cylindrical part is provided on the second pin connection cylindrical part. The first pin passes through the first pin inner installation through hole and two first pin outer installation through holes to connect the ceramic adapter and the first adapter.
[0011] Second pin outer installation through holes passing through the axis of the second pin connection cylindrical part are provided on the two cylindrical walls of the second pin connection cylindrical part. The ceramic pin passes through the pin holes on the circular cross-section specimen connector and the two second pin outer installation through holes to connect the ceramic adapter and the circular cross-section specimen.
[0012] Chamfers are provided at the joints of the second pin connection cylindrical part and the second pin connection cylindrical part with the second cylindrical solid part.
[0013] The first adapter includes: a stud part, a first cylindrical solid part, and a first pin connection cylindrical part. The stud part and the first pin connection cylindrical part are respectively integrally fixed to one end face of the first cylindrical solid part. The axes of the stud part, the first cylindrical solid part, and the first pin connection cylindrical part are collinear. First pin outer installation through holes passing through the axis of the first pin connection cylindrical part are provided on the two cylindrical walls of the first pin connection cylindrical part.
[0014] An annular groove is formed on the outer periphery of the first cylindrical solid part, and the stud part is coated with a colloidal anti-seize compound.
[0015] The circular cross-section specimen is a specimen made of a metal matrix material; the operating temperature of the heating constant temperature oven is 1100 degrees Celsius.
[0016] The first adapter and the first pin are made of the same material; the ceramic adapter and the ceramic pin are made of the same material.
[0017] Both the ceramic adapter and the ceramic pin are made of high-strength high-temperature-resistant Zr02 ceramic material.
[0018] A working method for a tooling fixture for axially stretching a sample is also provided. The technical solution includes:
[0019] Step 1: Connect two first adapters to the ceramic adapter through first pins to ensure a firm connection.
[0020] Step 2: Place a ceramic adapter in the space above the circular cross-section specimen, and use a ceramic pin shaft to assemble with the connector on the circular cross-section specimen through a shoulder connection.
[0021] Step 3: Place another ceramic adapter in the space below the circular cross-section specimen, and use a ceramic pin shaft to assemble with the lower connector on the circular cross-section specimen through a shoulder connection.
[0022] Step 4: Place two ceramic adapters, two ceramic pins and the circular cross-section specimen in the heating constant temperature oven, adjust the position of the circular cross-section specimen so that it is exactly in the middle of the heating constant temperature oven, and then conduct an ultra-high temperature axial tensile test.
[0023] Step 5: Raise the temperature, and keep the temperature constant after the temperature in the oven reaches the required temperature.
[0024] Step 6: Install the sample in the fixture of the high-temperature electronic tensile testing machine, ensure that the sample is centered and the clamping force is appropriate, and avoid slipping or breaking at an unexpected position during the test.
[0025] Step 7: Measure the coaxiality in the control system.
[0026] Step 8: Install the extensometer clamp.
[0027] Step 9: Start the temperature inspection system of the testing machine, start monitoring the temperature change, and when the temperature reaches and stabilizes, start the tensile test and record the data during the tensile process.
[0028] Step 10: After the test is completed, cool down to room temperature, take out the fixture, clean the residue, and check the fixture.
[0029] The beneficial effects of the present invention are as follows:
[0030] 1. The chucks on both sides of the circular cross-section specimen are connected to the upper connecting rod and the lower connecting rod of the tensile testing machine through ceramic adapters and the first adapter respectively. The materials of the connecting stress-bearing parts are all made of high-temperature-resistant ceramic materials, which are suitable for the axial tensile test of materials in high-temperature and ultra-high-temperature environments, overcoming the limitations of traditional metal tooling fixtures at high temperatures, and can accurately test the axial tensile properties of materials at temperatures above 1000 °C or even higher, thus effectively improving the accuracy of test results. At the same time, placing the first adapter outside the heating constant-temperature box further reduces the possibility of high-temperature damage to the tooling.
[0031] 2. The axis of the pin shafts above and below the ceramic adapter is perpendicular in space, so that both ceramic adapters bear the high-temperature axial strength and shear strength of the components during the entire high-temperature tensile test, meeting the strength requirements of metal matrix material specimens under extremely high-temperature conditions.
[0032] 3. The overall structure of the tooling fixture is reasonably designed. The symmetrical structure, smooth transition mechanism and curve reduce stress concentration, improving the strength and reliability of the tooling fixture. The modular design facilitates installation, disassembly and replacement, improving the convenience of use. Description of the Drawings
[0033] Figure 1 It is the front view schematic diagram of an embodiment of the tooling fixture for an axial tensile sample of the present invention;
[0034] Figure 2 It is the front view schematic diagram of the first adapter in the embodiment of the present utility model;
[0035] Figure 3 It is the front view schematic diagram of the ceramic adapter in the embodiment of the present utility model.
[0036] 1 - Upper connecting rod of the tensile testing machine, 2 - First adapter, 3 - Ceramic adapter, 4 - Upper connecting head of the circular cross-section specimen, 5 - Lower connecting head of the circular cross-section specimen, 6 - Lower connecting rod of the tensile testing machine, 7 - First pin, 8 - Ceramic pin, 9 - Heating constant-temperature box, 21 - Stud part, 22 - First cylindrical solid part, 23 - First pin connection cylindrical part, 31 - Second pin connection cylindrical part, 32 - Second cylindrical solid part, 231 - First pin outer installation through hole, 221 - Ring groove, 33 - Second pin connection cylindrical part, 311 - First pin inner installation through hole, 331 - Second pin outer installation through hole. Detailed Embodiment
[0037] The following further elaborates on the present invention in conjunction with the drawings.
[0038] As Figures 1 to 3The embodiment of the utility model shown includes: a circular cross-section specimen 100, two first adapters 2, two ceramic adapters 3, two ceramic pins 8, two first pins 7, and a tensile testing machine 200. The tensile testing machine 200 includes: an upper connecting rod 1 of the tensile testing machine, a lower connecting rod 6 of the tensile testing machine, and other components of the tensile testing machine. The two ceramic adapters 3, the two ceramic pins 8, and the circular cross-section specimen 100 are all located in a heating and constant temperature box 9.
[0039] The upper connecting rod 1 and the lower connecting rod 6 of the tensile testing machine 200 are both threadedly connected to the stud portion 21 of a first adapter 2.
[0040] The second pin connection cylindrical portions 31 of the two ceramic adapters 3 are respectively inserted into the first pin connection cylindrical portions 23 of a first adapter 2, and the first pin connection cylindrical portion 23 is connected to the second pin connection cylindrical portion 31 by a first pin 7.
[0041] The circular cross-section specimen 100 includes: an upper connection head 4 of the circular cross-section specimen, a circular cross-section test portion, and a lower connection head 5 of the circular cross-section specimen. The two connection heads (the upper connection head 4 and the lower connection head 5 of the circular cross-section specimen) of the circular cross-section specimen 100 are respectively inserted into the second pin connection cylindrical portions 33 of a ceramic adapter 3. The second pin connection cylindrical portion 33 of the upper ceramic adapter 3 is connected to the upper connection head 4 of the circular cross-section specimen 100 by a ceramic pin 8, and the second pin connection cylindrical portion 33 of the lower ceramic adapter 3 is connected to the lower connection head 5 of the circular cross-section specimen 100 by another first pin 7.
[0042] The axes of the circular cross-section specimen 100, the two first adapters 2, and the two ceramic adapters 3 are collinear. The axes of the two first pins 7 are parallel, and the axes of the two ceramic pins 8 are parallel. The projection of the axis of the first pin 7 and the axis of the ceramic pin 8 on the reference plane is perpendicular and perpendicularly passes through the axis of the circular cross-section specimen 100, and the reference plane is perpendicular to the axis of the circular cross-section specimen 100.
[0043] As Figure 2 The first adapter 2 shown includes: a stud portion 21, a first cylindrical solid portion 22, and a first pin connection cylindrical portion 23. The stud portion 21 and the first pin connection cylindrical portion 23 are respectively integrally fixed to one end face of the first cylindrical solid portion 22. The axes of the stud portion 21, the first cylindrical solid portion 22, and the first pin connection cylindrical portion 23 are collinear. First pin outer mounting through holes 231 passing through the axis of the first pin connection cylindrical portion 23 are opened on both cylinder walls of the first pin connection cylindrical portion 23.
[0044] As Figure 3The shown ceramic adapter 3 includes: a second pin connecting cylindrical portion 31, a second cylindrical solid portion 32, and a second pin connecting cylindrical tubular portion 33; wherein the second pin connecting cylindrical portion 31 and the second pin connecting cylindrical tubular portion 33 are integrally and fixedly connected to one end face of the second cylindrical solid portion 32 respectively; the axes of the second pin connecting cylindrical portion 31, the second cylindrical solid portion 32, and the second pin connecting cylindrical tubular portion 33 are collinear;
[0045] A first pin inner mounting through hole 311 passing through the axis of the second pin connecting cylindrical portion 31 is formed on the second pin connecting cylindrical portion 31. The first pin 7 passes through the first pin inner mounting through hole 311 and two first pin outer mounting through holes 231, thereby connecting the ceramic adapter 3 and the first adapter 2;
[0046] Second pin outer mounting through holes 331 passing through the axis of the second pin connecting cylindrical tubular portion 33 are formed on the two cylindrical walls of the second pin connecting cylindrical tubular portion 33. The ceramic pin 8 passes through the pin holes on the circular cross-section specimen 100 connector (the upper connector 4 and the lower connector 5 on the circular cross-section specimen) and two second pin outer mounting through holes 331, thereby connecting the ceramic adapter 3 and the circular cross-section specimen 100.
[0047] In this embodiment, an annular groove 221 is formed on the outer periphery of the first cylindrical solid portion 22 to better relieve the deformation of the fixture.
[0048] In this embodiment, the circular cross-section specimen 100 is a specimen made of a metal matrix material; the working temperature of the heating constant temperature oven 9 is 1100 degrees Celsius; the tensile forces applied by the upper connecting rod 1 and the lower connecting rod 6 of the tensile testing machine in the up and down directions are both 5000 N;
[0049] In this embodiment, to ensure that the thermal expansion coefficients at the joints are the same at high temperatures, the first adapter 2 and the first pin 7 are made of the same material, both made of GH4698 nickel-based superalloy material.
[0050] In this embodiment, to ensure that the thermal expansion coefficients at the joints are the same at high temperatures, the ceramic adapter 3 and the ceramic pin 8 are made of the same material, both made of high-strength high-temperature-resistant Zr02 ceramic material; the furnace part connected to the circular cross-section specimen 100 is separated. The traditional high-temperature alloy fixture used is a single crystal structure in the Ni-based forming process. Due to the thermal cycle from room temperature to 1100 °C during repeated experiments, the recrystallization of the single crystal fixture structure occurs on the surface, weakening the excellent high-temperature performance of the single crystal structure due to the change of the material structure. The failure mechanism is the crack propagation and fracture between the polycrystalline structures on the surface of the fixture; while Zr02 ceramic has the characteristic of high-temperature resistance. Dividing the adapter into two structures with different materials and only setting the ceramic adapter 3 in the heating constant temperature oven 9 can change the fracture problem of the fixture caused by crystallization.
[0051] In this embodiment, arc chamfers are provided between the three parts of the ceramic adapter 3. Due to the smooth transition design, it is more convenient for machining. After machining, the surface is polished and buffed to meet certain requirements for surface roughness (for example, Ra ≤ 0.8 μm).
[0052] In this embodiment, the size of the stud portion 21 is M18*2 - 6g, and a gum-like anti-seize compound is applied.
[0053] In this embodiment, the materials of the upper connecting rod 1 and the lower connecting rod 6 of the tensile testing machine are Ni-based alloys; during the design, it is necessary to test the thermal expansion coefficients of the Ni-based alloy, the material of the circular cross-section specimen 100, and the material of the first adapter 2, and calculate the clearances of the ceramic adapter 3, the ceramic pin 8, and the circular cross-section specimen 100 to effectively ensure the adjustability of the axial loading force, and thus ensure the coaxiality during the testing process. Ensure the uniformity of the stress-strain acquisition of the sample.
[0054] The working method is as follows:
[0055] Step 1: Connect the two first adapters to the ceramic adapter through the first pins to ensure a firm connection; specifically, first pass the first pins 7 through the first pin inner mounting through-holes 311 and the two first pin outer mounting through-holes 231 respectively, so as to combine two pairs of the first adapters 2 and the ceramic adapter 3; connect a pair of the first adapters 2 and the ceramic adapter 3 to the upper connecting rod 1 of the tensile testing machine through the stud portion 21, and then connect the other pair of the first adapters 2 and the ceramic adapter 3 to the lower connecting rod 6 of the tensile testing machine through the stud portion 21;
[0056] Step 2: Place a ceramic adapter in the upper space of the circular cross-section specimen 100, and assemble it with the upper connector 4 of the circular cross-section specimen by using a ceramic pin shaft through a shoulder connection method; specifically, connect the upper pair of the first adapters 2 and the ceramic adapter 3 to the upper connector 4 of the circular cross-section specimen through the ceramic pin 8;
[0057] Step 3: Place the other ceramic adapter in the lower space of the circular cross-section specimen 100, and assemble it with the lower connector 5 of the circular cross-section specimen by using a ceramic pin shaft through a shoulder connection method; specifically, after adjusting the height of the lower connecting rod 6 of the tensile testing machine, connect the lower pair of the first adapters 2 and the ceramic adapter 3 to the lower connector 5 of the circular cross-section specimen through the ceramic pin 8; complete the installation of the fixture, the circular cross-section specimen 100, and the tensile testing machine 200; pay attention to ensuring the coaxiality and perpendicularity of the chuck and the connection part during the installation process;
[0058] Step 4: Place the whole fixture in the heating constant temperature oven 9, adjust the position of the circular cross-section specimen 100 so that it is exactly in the middle of the heating constant temperature oven 9, and then perform an ultra-high temperature axial tensile test;
[0059] Step 5: Raise the temperature. After the temperature inside the chamber reaches the required temperature, keep it insulated. In Step 5, use a platinum-rhodium 30 - platinum-rhodium 6 temperature measurement system to calibrate the temperature source to ensure that the temperature measurement accuracy reaches 0.1°C.
[0060] Step 6: Install the sample in the fixture of the high-temperature electronic tensile testing machine, ensuring that the sample is centered and the clamping force is appropriate (closed-loop control) to avoid slippage or fracture at an unexpected position during the test.
[0061] Step 7: Measure the coaxiality in the control system and set parameters such as the tensile rate and the acquisition frequency of 80 Hz according to the experimental requirements.
[0062] Step 8: Install the extensometer clamp.
[0063] Step 9: Start the temperature inspection system of the testing machine and begin to monitor the temperature change. When the temperature reaches and stabilizes (1100 degrees Celsius in this embodiment), start the tensile test and record key data such as the stress-strain curve, fracture strength, elongation rate, etc. during the tensile process.
[0064] Step 10: After the test is completed, lower the temperature to room temperature, remove the fixture, clean the residues, and check whether the fixture is damaged or worn. If necessary, replace or repair it.
[0065] Through test verification, the tensile device of the present invention performs excellently under high-temperature conditions above 1100°C and can effectively conduct tensile mechanical tests. Whether at room temperature or high temperature, the device can stably and accurately measure performance parameters such as the tensile strength, stress-strain curve, fracture strength, elongation rate, and yield strength of metal and ceramic matrix composites, meeting the requirements of the coaxiality of the equipment's axial tensile direction being lower than 8% and the software data acquisition frequency being 80 Hz. The fixture will not cause damage to the specimen during clamping, ensuring the accuracy, reliability, and good repeatability of the test results. The fracture of all specimens occurs within the specified gauge length, effectively avoiding the situation where the tensile specimen cannot be completed due to premature damage of the clamping part, which further confirms the rationality of the design of this fixture.
Claims
1. An industrial fixture for axially stretching a sample, comprising: A circular cross-section specimen (100), two first adapters (2), two first pins (7), a heating and constant temperature oven (9), and a tensile testing machine (200), wherein the tensile testing machine (200) includes: an upper connecting rod (1) and a lower connecting rod (6) of the tensile testing machine; characterized in that it further includes: two ceramic adapters (3) and two ceramic pins (8), and the upper connecting rod (1) and the lower connecting rod (6) of the tensile testing machine (200) are both threadedly connected to the stud portion (21) of a first adapter (2); the second pin connection cylindrical portions (31) of the two ceramic adapters (3) are respectively inserted into the first pin connection cylindrical portions (23) of a first adapter (2), and the first pin connection cylindrical portion (23) is connected to the second pin connection cylindrical portion (31) by a first pin (7); The circular cross-section specimen (100) includes: an upper connecting head (4) of the circular cross-section specimen, a circular cross-section testing portion, and a lower connecting head (5) of the circular cross-section specimen. The upper connecting head (4) and the lower connecting head (5) of the circular cross-section specimen are respectively inserted into the second pin connection cylindrical portions (33) of a ceramic adapter (3); the second pin connection cylindrical portion (33) of the upper ceramic adapter (3) is connected to the upper connecting head (4) of the circular cross-section specimen (100) by a ceramic pin (8), and the second pin connection cylindrical portion (33) of the lower ceramic adapter (3) is connected to the lower connecting head (5) of the circular cross-section specimen (100) by another first pin (7); The two ceramic adapters (3), the two ceramic pins (8), and the circular cross-section specimen (100) are located in the heating and constant temperature oven (9).
2. The tooling fixture for an axially stretched sample according to claim 1, characterized in that, The axes of the circular cross-section specimen (100), the two first adapters (2), and the two ceramic adapters (3) are collinear. The projection of the axis of the first pin (7) and the axis of the ceramic pin (8) on the reference plane are perpendicular and perpendicularly pass through the axis of the circular cross-section specimen (100), and the reference plane is perpendicular to the axis of the circular cross-section specimen (100).
3. The tooling fixture for an axially stretched sample according to claim 2, characterized in that, The axes of the two first pins (7) are parallel, and the axes of the two ceramic pins (8) are parallel.
4. A fixture for an axially tensile sample according to any one of claims 1 to 3, characterized in that, The ceramic adapter (3) includes: a second pin connection cylindrical portion (31), a second cylindrical solid portion (32), and a second pin connection cylindrical portion (33); wherein the second pin connection cylindrical portion (31) and the second pin connection cylindrical portion (33) are respectively integrally and fixedly connected to one end face of the second cylindrical solid portion (32); the axes of the second pin connection cylindrical portion (31), the second cylindrical solid portion (32), and the second pin connection cylindrical portion (33) are collinear; A first pin inner mounting through hole (311) passing through the axis of the second pin connection cylindrical portion (31) is formed on the second pin connection cylindrical portion (31). The first pin (7) passes through the first pin inner mounting through hole (311) and two first pin outer mounting through holes (231) to connect the ceramic adapter (3) and the first adapter (2); On both cylindrical walls of the second pin connection cylindrical part (33), there are second pin outer mounting through holes (331) passing through the axis of the second pin connection cylindrical part (33). The ceramic pin (8) passes through the pin holes on the connector of the circular cross-section specimen (100) and the two second pin outer mounting through holes (331) to connect the ceramic adapter (3) and the circular cross-section specimen (100). There are chamfers at the joints of the second pin connection cylindrical part (31) and the second pin connection cylindrical part (33) with the second cylindrical solid part (32).
5. The workholding fixture for an axially stretched sample according to claim 1, characterized in that, The first adapter (2) includes: a stud part (21), a first cylindrical solid part (22), and a first pin connection cylindrical part (23). The stud part (21) and the first pin connection cylindrical part (23) are integrally and fixedly connected to one end face of the first cylindrical solid part (22) respectively; the axes of the stud part (21), the first cylindrical solid part (22), and the first pin connection cylindrical part (23) are collinear; on both cylindrical walls of the first pin connection cylindrical part (23), there are first pin outer mounting through holes (231) passing through the axis of the first pin connection cylindrical part (23).
6. The workholding fixture for an axially tensile sample according to claim 5, characterized in that, There is an annular groove (221) on the outer circumference of the first cylindrical solid part (22), and the stud part (21) is coated with a gum-like anti-seize compound.
7. The workholding fixture for an axially stretched sample according to claim 1, wherein The circular cross-section specimen (100) is a specimen made of a metal matrix material; the working temperature of the heating and constant temperature oven (9) is 1100 degrees Celsius.
8. The tooling fixture for an axially stretched sample according to claim 1, characterized in that, The first adapter (2) and the first pin (7) are made of the same material; the ceramic adapter (3) and the ceramic pin (8) are made of the same material.
9. The tooling fixture for an axially stretched sample according to claim 8, characterized in that, The ceramic adapter (3) and the ceramic pin (8) are both made of high-strength and high-temperature-resistant Zr02 ceramic materials.
10. The working method of a tooling fixture for an axially stretched sample according to claim 1, characterized in that, Including: Step 1: Connect the two first adapters to the ceramic adapter through the first pins to ensure a firm connection. Step 2: Place a ceramic adapter in the upper space of the circular cross-section specimen, and use a ceramic pin shaft to assemble with the connector on the circular cross-section specimen through a shoulder connection method. Step 3: Place the other ceramic adapter in the lower space of the circular cross-section specimen, and use a ceramic pin shaft to assemble with the lower connector of the circular cross-section specimen through a shoulder connection method. Step 4: Place the two ceramic adapters, the two ceramic pins, and the circular cross-section specimen in the heating and constant temperature oven, adjust the position of the circular cross-section specimen so that it is exactly in the middle of the heating and constant temperature oven, and then conduct an ultra-high temperature axial tensile test. Step 5: Raise the temperature, and keep the temperature constant after the temperature in the oven rises to the required temperature. Step 6: Install the sample in the fixture of the high-temperature electronic tensile testing machine, ensure that the sample is centered and the clamping force is appropriate, and avoid slipping or breaking at an unexpected position during the test. Step 7: Measure the coaxiality in the control system. Step 8: Install the extensometer clamp. Step 9: Start the temperature inspection system of the testing machine, start monitoring the temperature change. When the temperature reaches and stabilizes, start the tensile test and record the data during the tensile process. Step 10: After the test is completed, when the temperature drops to room temperature, remove the fixture, clean the residues, and check the fixture.