Material-grade vacuum low-temperature environment mechanical test system

Abstract

The invention relates to a material-grade vacuum low-temperature environment mechanical test system, and relates to the technical field of vacuum low-temperature furnaces. Comprising a test host, vacuum equipment, a platform assembly, a mechanical pump set and an exhaust device. Vacuum equipment and a platform assembly are mounted on the test host in a sliding manner and are used for supporting the vacuum equipment and the platform assembly; the vacuum equipment is used for providing a vacuum environment for the test sample and carrying out various tests on the test sample; the platform assembly is communicated with vacuum equipment through a vacuum pipeline; the mechanical pump set is connected with the vacuum pipeline through a vacuumizing pipeline and is used for pumping out gas in the vacuum equipment; and the exhaust device is mounted on the vacuum equipment and used for exhausting air and monitoring the air pressure state in the vacuum equipment. The device can provide a static mechanical test, a fatigue test and a material fatigue test, and can be used in multiple scenes of material fatigue test, stretching, compression, bending, shearing and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of vacuum cryogenic furnaces, and specifically to a material-level vacuum cryogenic environmental mechanics test system. Background Technique

[0002] With the development of fields such as aerospace, nuclear fusion energy, hydrogen energy, applied superconductivity, gas industry, and some large scientific projects in China, there are more and more projects involving cryogenic engineering. These fields have an increasing demand for cryogenic materials, and at the same time, the requirements for the performance data of cryogenic materials are becoming more and more comprehensive;

[0003] Cryogenic materials refer to metal and its alloy materials suitable for use from below zero degrees to absolute zero. When materials work in a cryogenic environment, their various mechanical properties are very different from those in a normal temperature environment. Among them, the mechanical properties of materials are an important performance index of materials or workpieces in engineering. Testing the mechanical properties of materials at low temperatures is of great significance for the research and optimization modification of the low-temperature properties of materials, and is also crucial for the design and safe use of cryogenic components.

[0004] At present, the commonly used cryogenic environment is mostly obtained by the method of liquid nitrogen (-196°C) refrigeration. The low-temperature mechanical support and the sample to be tested are immersed in the liquid nitrogen test device for testing to obtain various low-temperature mechanical property indexes of the material. However, the existing test device is made of low-temperature stainless steel material, and it is impossible to complete the material test in multiple scenarios during the test process, which hinders the further research on the low-temperature properties of materials.

[0005] Therefore, how to provide a material-level vacuum cryogenic environmental mechanics test system has become an urgent technical problem for those skilled in the art. Summary of the Invention

[0006] To solve at least one technical problem in the background technique, the present invention provides a material-level vacuum cryogenic environmental mechanics test system, which can provide static mechanics tests (tensile, compression, creep, relaxation, bending, etc.), fatigue tests (low-cycle fatigue test, high-cycle fatigue test), and material fatigue tests, and has multiple scenarios such as material fatigue test, tensile, compression, bending, and shear to solve the problems proposed in the above background technique.

[0007] To achieve the above object, the present invention provides a material-level vacuum cryogenic environmental mechanics test system, including: a test mainframe, a vacuum device, a platform assembly, a mechanical pump group, and an exhaust device;

[0008] The vacuum device and the platform assembly are slidably installed on the test mainframe for supporting the vacuum device and the platform assembly;

[0009] The vacuum device is used to provide a vacuum environment for the test sample and to perform various tests on the test sample;

[0010] The platform component is connected to the vacuum device through a vacuum pipeline;

[0011] The mechanical pump set is connected to the vacuum pipeline through a vacuum extraction pipeline and is used to extract the gas inside the vacuum device;

[0012] The exhaust device is installed on the vacuum device and is used for exhausting and monitoring the air pressure state inside the vacuum device.

[0013] Further, the test main machine includes a test machine table, a bottom plate is fixedly connected to the test machine table, legs are symmetrically and fixedly connected to the rear side of the lower end surface of the bottom plate, guide rails are symmetrically and fixedly connected to the front side position of the bottom plate, and a bracket for supporting and fixing the vacuum device is slidably connected to the guide rails.

[0014] Further, the platform component includes a molecular pump slidably connected to the guide rail, an inlet valve is fixed on the molecular pump, the inlet valve is connected to a vacuum pipeline, a manual butterfly valve is fixed on the vacuum pipeline, and one end of the vacuum pipeline is connected to the vacuum device.

[0015] Further, the mechanical pump set includes a plurality of mechanical pumps, and the mechanical pumps are connected to the vacuum pipeline through a vacuum extraction pipeline.

[0016] Further, the vacuum device includes a vacuum furnace, a furnace body cold shield is fixed inside the vacuum furnace, the inside of the furnace body cold shield is a vacuum cavity, a cold spray nozzle is arranged in the vacuum cavity, a liquid baffle is fixed at the front side position of the bottom of the vacuum cavity, a pull rod reducing pair plate is fixed at the rear side of the liquid baffle, tension clamps are symmetrically and fixedly connected to the top of the pull rod reducing pair plate and the top of the vacuum cavity, and a test sample is arranged between the two tension clamps.

[0017] Further, a pull rod assembly is fixedly connected between the bottom of the vacuum furnace and the bottom plate and at the top of the vacuum furnace, the two pull rod assemblies respectively penetrate through the vacuum furnace and are fixed to the tension clamps, a corrugated pipe is sleeved outside the pull rod assembly, and the corrugated pipe is fixed to the pull rod assembly and the vacuum furnace respectively through flanges.

[0018] Further, a hatch is arranged at the front side of the vacuum furnace, a furnace door cold shield is fixed inside the hatch, the furnace door cold shield corresponds to the furnace body cold shield, and the hatch is fixedly connected to the vacuum furnace through a door hinge.

[0019] Further, a door lock for fixing the hatch is also fixed at the front side of the vacuum furnace, and an observation window is fixed at the front side of the hatch and extends into the furnace door cold shield.

[0020] Further, a refrigerant inlet and a vacuum connector are respectively fixed to the rear side of the vacuum furnace. The vacuum connector is located below the refrigerant inlet. A refrigerant nozzle is fixed inside the refrigerant inlet. The refrigerant nozzle corresponds to the test sample. The vacuum connector communicates with the vacuum chamber.

[0021] Further, the exhaust device includes a pressure monitor, a solenoid valve, and an exhaust pipeline. The top of the vacuum furnace communicates with the exhaust pipeline. The solenoid valve is arranged on the exhaust pipeline. A vacuum gauge is arranged on the vacuum furnace. The pressure monitor is fixed on one side of the solenoid valve.

[0022] The beneficial effects of the present invention are as follows:

[0023] The present invention can provide static mechanics tests (tensile, compression, creep, relaxation, bending, etc.), fatigue tests (low-cycle fatigue test, high-cycle fatigue test), and a material fatigue test control system to realize material fatigue testing, and has multiple scenarios for use such as tensile, compression, bending, and shear.

[0024] The present invention can provide a vacuum low-temperature environment system, which is a special temperature device adapted to the material fatigue test control system, and can provide an extreme temperature environment for the fatigue test of test material structures. It can be adapted to the residual stress measurement and analysis system, and can realize rapid and accurate residual stress testing to obtain residual stress results, full-width at half-maximum results, qualitatively analyze grain size, texture / orientation information.

[0025] The present invention can perform functions of vacuum environment, extreme temperature loading, and key information measurement. The testing machine provides a research basis for scientific innovation in the aspect of extreme multi-field coupling damage and failure of materials. Description of the Drawings

[0026] Figure 1 It is a view of the overall structure of the present invention;

[0027] Figure 2 It is a rear view of the overall structure of the present invention;

[0028] Figure 3 It is a left view of the overall structure of the present invention;

[0029] Figure 4 It is a front view of the overall structure of the present invention.

[0030] In the figure: 1. Testing machine platform; 2. Base plate; 3. Guide rail; 4. Bracket; 5. Cold shield of furnace door; 6. Cabin door; 7. Observation window; 8. Cold shield of furnace body; 9. Cold spray nozzle; 10. Test sample; 11. Door lock; 12. Pressure monitor; 13. Vacuum gauge; 14. Solenoid valve; 15. Bellows; 16. Tensile fixture; 17. Tie rod assembly; 18. Vacuum chamber; 19. Vacuum pipeline; 20. Gate valve; 21. Molecular pump; 22. Mechanical pump; 23. Leg; 24. Manual butterfly valve; 25. Refrigerant inlet; 26. Door hinge; 27. Liquid baffle; 28. Reducing pair plate of tie rod; 29. Vacuum connector. Detailed implementation manner

[0031] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0032] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily need to be used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so as to describe the embodiments of the present invention here. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device including a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0033] In the present invention, the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "front", "rear", "top", "bottom", "inner", "outer", "middle", "vertical", "horizontal", "lateral", "longitudinal", etc. is based on the orientation or positional relationship shown in the drawings. These terms are mainly used to better describe the present invention and its embodiments, and are not used to limit that the indicated devices, elements or components must have a specific orientation or be constructed and operated in a specific orientation.

[0034] Moreover, in addition to being able to represent the orientation or positional relationship, some of the above terms may also be used to represent other meanings. For example, the term "upper" may also be used to represent a certain attachment relationship or connection relationship in some cases. For those of ordinary skill in the art, the specific meanings of these terms in the present invention can be understood according to specific circumstances.

[0035] In addition, the terms "installed", "set up", "provided with", "connected", "linked", "socketed" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or an internal communication between two devices, components or parts. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0036] To achieve the above object, as Figures 1-4 shown, the present invention provides a material-level vacuum low-temperature environmental mechanics test system, including: a test host, a vacuum device, a platform assembly, a mechanical pump set, and an exhaust device;

[0037] The vacuum device and the platform assembly are slidably installed on the test host for supporting the vacuum device and the platform assembly;

[0038] The vacuum device is used to provide a vacuum environment for the test sample 10 and to perform various tests on the test sample 10;

[0039] The platform assembly is communicated with the vacuum device through a vacuum pipeline 19;

[0040] The mechanical pump set is connected to the vacuum pipeline 19 through a vacuum pumping pipeline for pumping out the gas in the vacuum device;

[0041] The exhaust device is installed on the vacuum device for exhausting and monitoring the air pressure state in the vacuum device.

[0042] The test host includes a test machine table 1, a bottom plate 2 is fixedly connected to the test machine table 1, legs 23 are symmetrically and fixedly connected to the rear side of the lower end surface of the bottom plate 2, guide rails 3 are symmetrically and fixedly connected to the front side position of the bottom plate 2, and a bracket 4 for supporting and fixing the vacuum device is slidably connected to the guide rails 3.

[0043] The platform assembly includes a molecular pump 21 slidably connected to the guide rail 3, a gate valve 20 is fixed on the molecular pump 21, the gate valve 20 is connected to a vacuum pipeline 19, a manual butterfly valve 24 is fixed on the vacuum pipeline 19, and one end of the vacuum pipeline 19 is communicated with the vacuum device.

[0044] The mechanical pump set includes a plurality of mechanical pumps 22, and the mechanical pumps 22 are connected to the vacuum pipeline 19 through a vacuum pumping pipeline.

[0045] The vacuum device includes a vacuum furnace, inside which a furnace body cold shield 8 is fixed. The inside of the furnace body cold shield 8 is a vacuum cavity 18. A cold spray nozzle 9 is arranged in the vacuum cavity 18. A liquid baffle 27 is fixed at the front side of the bottom of the vacuum cavity 18. A pull rod diameter reduction pair plate 28 is fixed at the rear side of the liquid baffle 27. Tensile jigs 16 are symmetrically and fixedly connected to the top of the pull rod diameter reduction pair plate 28 and the top of the vacuum cavity 18. A test sample is arranged between the two tensile jigs 16.

[0046] Further optimizing the technical solution, a pull rod assembly 17 is fixedly connected between the bottom of the vacuum furnace and the bottom plate 2 and at the top of the vacuum furnace. The two pull rod assemblies 17 respectively penetrate the vacuum furnace and are fixed to the tensile jigs 16. A bellows 15 is sleeved outside the pull rod assembly 17. The bellows 15 is fixed to the pull rod assembly 17 and the vacuum furnace respectively through flanges.

[0047] Further optimizing the technical solution, a hatch door 6 is arranged at the front side of the vacuum furnace. A furnace door cold shield 5 is fixed inside the hatch door 6. The furnace door cold shield 5 corresponds to the furnace body cold shield 8. The hatch door 6 and the vacuum furnace are fixedly connected through a door hinge 26.

[0048] Further optimizing the technical solution, a door lock 11 for fixing the hatch door 6 is also fixed at the front side of the vacuum furnace. An observation window 7 is fixed at the front side of the hatch door 6. The observation window 7 extends into the furnace door cold shield 5. A vacuum flange is fixed on the observation window 7, and a vacuum valve body is fixed at the top of the vacuum valve. The observation window 7 is a vacuum pipe fitting, and a KF50 observation window is fixed at the front side of the vacuum pipe fitting. The purpose of setting the observation window 7 is to realize the intervention of external optical measurement DIC. Since the furnace body will not frost and the test sample will not frost after the vacuum furnace is evacuated, then DIC can directly observe the test sample through this observation window 7 to obtain the deformation process and mechanical response of the test sample at low temperature.

[0049] Further optimizing the technical solution, a refrigerant inlet 25 and a vacuum connector 29 are respectively fixed at the rear side of the vacuum furnace, where the vacuum connector 29 is located below the refrigerant inlet 25. A refrigerant spray nozzle is fixed inside the refrigerant inlet 25. The refrigerant spray nozzle corresponds to the test sample. The vacuum connector 29 communicates with the vacuum cavity.

[0050] The exhaust device includes a pressure monitor, a solenoid valve 14, and an exhaust pipe line; the top of the vacuum furnace is communicated with the exhaust pipe line. The solenoid valve 14 is arranged on the exhaust pipe line. A vacuum gauge 13 is arranged on the vacuum furnace. A pressure monitor 12 is fixed on one side of the solenoid valve 14. The pressure monitor 12 adopts a fixed pressure gauge or a pressure transmitter.

[0051] The present invention can provide a static mechanical test system for tensile, compression, creep, relaxation, bending, etc., and a fatigue test system for low-cycle fatigue test and high-cycle fatigue test, as well as a material fatigue test control system, realizing material fatigue test and multi-scenario use for tensile, compression, bending, shear, etc.; the present invention can provide a vacuum low-temperature environment system, which is a special temperature device adapted to the material fatigue test control system, and can provide an extreme temperature environment for the fatigue test of test material structural parts. And by vacuum pumping to create negative pressure, the temperature can be further reduced. The medium used in the present invention is liquid helium, generally at 4K. Then, with vacuum, the temperature will become 2K under ideal conditions, thus further reducing the temperature and more accurately simulating the extreme temperature environment; before the test, the air inside the furnace body will be purged with nitrogen to remove the internal air. In this way, when the furnace body is evacuated, there will be no water vapor inside, so there will be no frosting due to low temperature, no frosting on the specimen, and the specimen state inside the furnace body can be clearly seen. In addition, the present invention can also be adapted to a residual stress measurement and analysis system, enabling rapid and accurate residual stress testing to obtain residual stress results, full-width at half-maximum results, qualitatively analyze grain size, texture / orientation information; the present invention can perform vacuum environment, extreme temperature loading and key information measurement functions, and the testing machine provides a research basis for scientific innovation in the aspect of extreme multi-field coupling damage and failure of materials. The present invention combines the advantages of traditional low-temperature environmental chambers and closed low-temperature dewars, being able to both observe the test and ensure the low temperature of the specimen.

[0052] The control parameters of the present invention are as follows:

[0053] 1. The working vacuum degree of the vacuum low-temperature environment system: less than 20 Pa within 30 minutes;

[0054] 2. The leakage rate of the vacuum chamber of the vacuum low-temperature environment system: ≤ 0.5 Pa / h;

[0055] 3. The vacuum low-temperature environment system adopts a low-temperature medium refrigeration method;

[0056] 4. The vacuum low-temperature environment system can ensure that the surface temperature of the test specimen ≤ 4K;

[0057] 5. The temperature control accuracy of the vacuum low-temperature environment system: ≤ ±5°C;

[0058] 6. Frosting is not allowed on the viewing window of the vacuum low-temperature environment system;

[0059] 7. The vacuum low-temperature environment system is equipped with a pressure monitoring and overpressure protection device;

[0060] 8. The vacuum low-temperature environment system is equipped with a low-temperature sensor with a resolution of not less than 45 μK;

[0061] 9. The vacuum low-temperature environment system is equipped with a pressure sensor with an accuracy higher than 0.3 level;

[0062] 10. Vacuum low-temperature environment system low-temperature valve adaptation density: ≥124.98 kg / m 3 , working

[0063] temperature: -268.9 °C, flow rate: 2 L / min, caliber: 1 / 4 inch;

[0064] 11. Fatigue loading function of materials and components in ultra-low temperature vacuum environment;

[0065] 12. The lowest actual temperature of the test specimen is ≥2 K (-271 °C).

[0066] The working principle of the present invention is as follows:

[0067] Place the test sample 10 on the tensile fixture 16 and adjust the position; close the hatch 6.

[0068] Evacuate the vacuum chamber 18. The rough vacuum is completed by the mechanical pump 22. After that, the molecular pump 21 pumps the high vacuum. After completion, close the manual butterfly valve 24 to cut off the connection between the vacuum chamber 18 and the vacuum pipeline 19 to prevent the pipeline from frosting. An independent small pump is used between the shell layers to achieve rough vacuum to isolate the environmental temperature from conducting into the chamber.

[0069] At this time, a high vacuum environment has been formed in the vacuum chamber 18, and water vapor and other gases have been almost emptied. Then, start to spray liquid nitrogen or liquid helium at low temperature to cool the specimen. The spraying amount of the refrigerant is controlled by the solenoid valve 14, forming a closed-loop control with the temperature sensor and the controller. A cold shield is designed in the chamber to isolate the temperature, and the inner layer of the shell has also been evacuated to further isolate the environmental temperature. When the refrigerant starts to be sprayed, it will cause the internal pressure of the original vacuum chamber to increase. When the pressure sensor detects the pressure increase, it will open the exhaust valve. Almost at the same time as the refrigerant is sprayed, the exhaust valve will open to ensure that there is no water vapor condensation on the observation window 7. Use the observation device to monitor the change process of the sample through the observation window 7.

[0070] The above is only a preferred embodiment of the present invention, and does not impose any limitation on the technical scope of the present invention. Therefore, any minor modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A material-level vacuum cryogenic environmental mechanical test system, characterized in that, Comprising: A test mainframe, a vacuum device, a platform component, a mechanical pump set, and an exhaust device; A vacuum device and a platform component are slidably mounted on the test mainframe for supporting the vacuum device and the platform component; The vacuum device is used to provide a vacuum environment for the test sample (10) and perform various tests on the test sample (10); The platform component is connected to the vacuum device through a vacuum pipeline (19); The mechanical pump set is connected to the vacuum pipeline (19) through a vacuum pumping pipeline for pumping out the gas in the vacuum device; The exhaust device is installed on the vacuum device for exhausting and monitoring the air pressure state in the vacuum device.

2. The material-level vacuum cryogenic environmental mechanical test system according to claim 1, characterized in that, The test mainframe includes a test machine table (1), a bottom plate (2) is fixedly connected to the test machine table (1), legs (23) are symmetrically and fixedly connected to the rear side of the lower end surface of the bottom plate (2), guide rails (3) are symmetrically and fixedly connected to the front side position of the bottom plate (2), and a bracket (4) for supporting and fixing the vacuum device is slidably connected to the guide rails (3).

3. The material-level vacuum cryogenic environmental mechanics test system according to claim 2, wherein, The platform component includes a molecular pump (21) slidably connected to the guide rails (3), a gate valve (20) is fixed on the molecular pump (21), the gate valve (20) is connected to a vacuum pipeline (19), a manual butterfly valve (24) is fixed on the vacuum pipeline (19), and one end of the vacuum pipeline (19) is connected to the vacuum device.

4. A material-level vacuum cryogenic environmental mechanics test system according to claim 1 or 3, characterized in that The mechanical pump set includes multiple mechanical pumps (22), and the mechanical pumps (22) are connected to the vacuum pipeline (19) through a vacuum pumping pipeline.

5. The material-level vacuum cryogenic environmental mechanical test system according to claim 1, wherein The vacuum device includes a vacuum furnace, a furnace body cold shield (8) is fixed inside the vacuum furnace, the inside of the furnace body cold shield (8) is a vacuum cavity (18), a cold spray nozzle (9) is arranged in the vacuum cavity (18), a liquid baffle (27) is fixed at the front side position of the bottom of the vacuum cavity (18), a pull rod reducing pair plate (28) is fixed at the rear side of the liquid baffle (27), stretching jigs (16) are symmetrically and fixedly connected to the top of the pull rod reducing pair plate (28) and the top of the vacuum cavity (18), and a test sample is arranged between the two stretching jigs (16).

6. The material-level vacuum cryogenic environmental mechanical test system according to claim 5, characterized in that, Between the bottom of the vacuum furnace and the bottom plate (2) and at the top of the vacuum furnace, pull rod assemblies (17) are fixedly connected. The two pull rod assemblies (17) respectively pass through the vacuum furnace and are fixed to the stretching jigs (16). A corrugated pipe (15) is sleeved outside the pull rod assemblies (17), and the corrugated pipe (15) is fixed to the pull rod assemblies (17) and the vacuum furnace through flanges respectively.

7. A material-level vacuum cryogenic environmental mechanical test system according to claim 6, characterized in that, A hatch door (6) is arranged at the front side of the vacuum furnace, a furnace door cold shield (5) is fixed inside the hatch door (6), the furnace door cold shield (5) corresponds to the furnace body cold shield (8), and the hatch door (6) and the vacuum furnace are fixedly connected through a door hinge (26).

8. The material-level vacuum cryogenic environmental mechanical test system according to claim 7, wherein A door lock (11) for fixing the hatch door (6) is also fixed at the front side of the vacuum furnace, and an observation window (7) is fixed at the front side of the hatch door (6), and the observation window (7) extends into the furnace door cold shield (5).

9. The material-level vacuum cryogenic environmental mechanical test system according to claim 8, wherein A refrigerant inlet (25) and a vacuum connector (29) are respectively fixed to the rear side of the vacuum furnace, wherein the vacuum connector (29) is located below the refrigerant inlet (25). A refrigerant nozzle is fixed inside the refrigerant inlet (25), and the refrigerant nozzle corresponds to the test sample. The vacuum connector (29) is communicated with the vacuum chamber.

10. A material-level vacuum cryogenic environmental mechanical test system as described in claim 5 or 9, characterized in that, The exhaust device includes a pressure monitor, a solenoid valve (14) and an exhaust pipeline; the top of the vacuum furnace is communicated with the exhaust pipeline, the solenoid valve (14) is arranged on the exhaust pipeline, a vacuum gauge (13) is arranged on the vacuum furnace, and a pressure monitor (12) is fixed on one side of the solenoid valve (14).

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