A testing device for ablative performance of composite material in vacuum environment

Abstract

The utility model belongs to performance test technical field relates to a kind of testing device of composite ablative performance under vacuum environment, comprising: low-pressure vacuum chamber and the device ontology in the low-pressure vacuum chamber;The device ontology includes support frame, and the inner wall of support frame is fixed with heat insulation layer, and support frame is equipped with temperature sensor, and support frame is equipped with sample support platform and heating lamp group, and heating lamp group is located above sample support platform, and sample support platform is placed with the sample to be measured, and the sample to be measured is connected with temperature sensor.The testing device, through low-pressure vacuum chamber creates vacuum oxygen-free environment, can effectively peel off oxidation reaction interference, to focus on the pure thermal physical ablation mechanism of the sample to be measured on performance test, to obtain intrinsic thermal response of the sample to be measured under thermal radiation.

Description

Technical Field

[0001] This utility model belongs to the field of performance testing technology and relates to a testing device for the ablation performance of composite materials under vacuum conditions. Background Technology

[0002] Currently, with the development of deep space exploration missions, reconnaissance satellites, manned spacecraft, and space shuttles all need to return to Earth promptly after completing their orbital flight missions. Due to the high speeds of these vehicles, they encounter severe aerodynamic heating upon entering the dense atmosphere, where surface temperatures can reach up to 1000°C. Furthermore, these vehicles are subjected to high pressure, strong erosion, and high heat flux during flight, all of which can lead to severe ablation of the surface materials, potentially damaging their internal properties. Therefore, investigating the ablation properties of materials is essential for evaluating the performance of spacecraft surface materials.

[0003] A Chinese patent document (publication number: CN110208318A, publication date: September 6, 2019) discloses a plasma ablation performance testing device. This device includes a pressure cap, an inner sample box sleeve, an outer sample box sleeve, a push rod, and a support base. In use, the inner and outer sample box sleeves are assembled and fixed to the ablation platform via the base. The sample is placed in the inner sample box sleeve. The pressure cap is threaded to one end of the outer sample box sleeve, simultaneously tightening the inner sample box sleeve. The push rod is threaded to the other end of the outer sample box sleeve, simultaneously fixing the sample in the inner sample box sleeve. Cooling circulating water is introduced by opening a valve. The ablation process parameters are set according to GJ323-1996, and the plasma ablation performance is tested using a plasma spray gun. Simultaneously, the temperature of the sample back wall is measured through the center hole of the push rod. The push rod is manually unscrewed to remove the sample.

[0004] Another Chinese patent document (publication number: CN116429816A, publication date: July 14, 2023) discloses an ablation resistance testing device, including a plasma gun, a testing platform, a heat flux density calibration device, and testing auxiliary fixtures; by cooperating with the plasma gun, the heat flux density calibration device, and the testing auxiliary fixtures, the device can meet the requirements for long-term ablation resistance testing of ultra-high / high melting point materials or coatings, and effectively solve the problems of fixture ablation and melting caused by long-term ablation resistance testing in the prior art.

[0005] While both patents can assess the ablation resistance of materials, they present several problems because they both use plasma flames as heat sources and are tested in an aerobic atmospheric environment. First, in an aerobic plasma flame, the material is simultaneously subjected to both oxidative corrosion and thermophysical degradation. It is difficult to separate these two effects during testing, thus failing to eliminate oxidation interference and making it impossible to accurately assess the ablation performance of the material under purely thermophysical conditions. Second, due to the uneven temperature distribution of the plasma flame, with significant differences between the high-temperature central region and the low-temperature peripheral region, the thermal effects are uneven. Therefore, during thermophysical ablation of the material, the intensity of thermal effects varies in different regions, making it impossible to accurately assess the overall ablation performance of the material. Finally, the equipment in both patents is complex and costly, and the high-pressure, high-temperature ionized gas in the plasma flame may pose an explosion risk in an aerobic environment, threatening the personal safety of technicians.

[0006] In view of the above, this utility model is hereby proposed. Utility Model Content

[0007] The purpose of this invention is to overcome the shortcomings of the prior art and provide a testing device for the ablation performance of composite materials in a vacuum environment, so as to solve the problems that the testing equipment in the prior art is costly and risky, and cannot accurately evaluate the ablation performance of the material as a whole under pure thermophysical action. This invention provides a testing device for the ablation performance of composite materials under vacuum conditions, comprising: a low-pressure vacuum chamber and a device body located within the low-pressure vacuum chamber; The device body includes a support frame, an insulation layer is fixed to the inner wall of the support frame, a temperature sensor is provided outside the support frame, a sample support platform and a heating lamp assembly are provided inside the support frame, the heating lamp assembly is located above the sample support platform, a sample to be tested is placed on the sample support platform, and the sample to be tested is connected to the temperature sensor.

[0008] Specifically, the sample support platform is set on the heat insulation layer on the bottom surface of the support frame, and the heating lamp assembly is fixedly installed on the heat insulation layer on the top surface of the support frame.

[0009] Specifically, the temperature sensor is a thermocouple.

[0010] Specifically, there are three thermocouples. Any one of the three thermocouples is connected to the heated surface of the sample to be tested, and the remaining two thermocouples are connected to the back side of the sample to be tested.

[0011] Specifically, it also includes a heat flow sensor, which is disposed within the support frame at a position level with the top surface of the sample support stage.

[0012] Specifically, the sample support platform has a hollow structure, comprising a primary support platform and a secondary support platform arranged sequentially from top to bottom; the bottom surface of the secondary support platform is fixedly connected to the heat insulation layer of the inner bottom surface of the support frame, and the bottom surface of the primary support platform is movably connected to the top surface of the secondary support platform. Preferably, the bottom surface area of ​​the primary support platform is smaller than that of the secondary support platform, and the top surface of the primary support platform is provided with a groove for placing the sample to be tested. Further, the groove is a circular groove or a square groove.

[0013] Specifically, the heating lamp assembly includes multiple arrays of quartz lamps to provide an ablation environment for the sample to be tested.

[0014] Compared with the prior art, the technical solution provided by this utility model has the following beneficial effects: This testing device, 1) By creating a vacuum oxygen-free environment through a low-pressure vacuum chamber, the interference of oxidation reaction can be effectively eliminated, thereby focusing the performance test on the pure thermophysical ablation mechanism of the sample under test, so as to obtain the intrinsic thermal response of the sample under test under thermal radiation.

[0015] 2) By fixing the heat insulation layer to the inner wall of the support frame, heat diffusion during the test can be effectively prevented. On the one hand, it can reduce the fire risk caused by heat transfer, and on the other hand, it can avoid the risk of burns or radiation to the workers caused by high temperature and high heat radiation. It can also keep the set heat flow value inside the test device, ensuring the thermal environment of the temperature field is stable during the test, thereby ensuring the authenticity of the test data.

[0016] 3) Through the array layout of the heating lamp group, uniform radiant heating in a plane can be achieved. Moreover, the heating lamp group uses quartz lamps with low purchase, operation and maintenance costs, which can quickly achieve heating and cooling. Therefore, the heating state can be quickly adjusted according to the test requirements, which is convenient for precise control of heating time and heat flux density, thus facilitating the testing of material ablation performance and improving testing efficiency.

[0017] 4) The temperature sensor can measure the temperature of the sample to be tested, and the heat flow sensor can monitor the heat flow to the surface of the sample to be tested in real time. By comparing the two data, it can be determined whether the heating heat flow to the surface of the sample to be tested is within the set value, which makes it easy to adjust the heat flow density of the test device. Attached Figure Description

[0018] The accompanying drawings are incorporated in and form part of this specification, and together with the description, serve to explain the principles of this invention.

[0019] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 A structural diagram of a test device for the ablation performance of composite materials under vacuum environment provided by this utility model; Figure 2 This is a schematic diagram of the structure of the device body provided in Embodiment 1 of this utility model; Figure 3 This is a schematic diagram of the structure of the device body provided in Embodiment 2 of this utility model.

[0021] The components include: 1. Low-pressure vacuum chamber; 2. Device body; 3. Sample support platform; 31. Primary support platform; 32. Secondary support platform; 4. Support frame; 5. Heating lamp assembly; 6. Temperature sensor; 7. Heat flow sensor; 8. Sample to be tested. Detailed Implementation

[0022] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this invention. Rather, they are merely examples consistent with some aspects of this invention as detailed in the appended claims.

[0023] To enable those skilled in the art to better understand the technical solution of this utility model, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments.

[0024] Example 1 See Figure 1 As shown in the figure, this embodiment provides a structural diagram of a test device for the ablation performance of composite materials under vacuum conditions. The test device includes: a low-pressure vacuum chamber 1 and a device body 2 located inside the low-pressure vacuum chamber 1. See Figure 2 The device body 2 includes a support frame 4, the inner wall of which is fixed with a heat insulation layer, a temperature sensor 6 is provided outside the support frame 4, a sample support stage 3 and a heating lamp group 5 are provided inside the support frame 4, the heating lamp group 5 is located above the sample support stage 3, a sample 8 to be tested is placed on the sample support stage 3, and the sample 8 to be tested is connected to the temperature sensor 6.

[0025] In this embodiment, the sample support platform 3 is disposed on the heat insulation layer on the bottom inner surface of the support frame 4, and the heating lamp group 5 is fixedly installed on the heat insulation layer on the top inner surface of the support frame 4.

[0026] The sample support platform 3 has a hollow structure, including a primary support platform 31 and a secondary support platform 32. The bottom surface of the secondary support platform 32 is fixedly connected to the heat insulation layer on the inner bottom surface of the support frame 4, while the bottom surface of the primary support platform 31 is movably connected to the top surface of the secondary support platform 32, facilitating quick disassembly of the primary support platform 31 to place the sample 8 to be tested. Here, the heat insulation layer is made of low-density carbon fiber / graphite fiber felt / blanket. This material has extremely low thermal conductivity (especially perpendicular to the fiber direction), excellent high-temperature stability (up to 2500℃ or higher under inert atmosphere or vacuum), low heat capacity, low outgassing rate (using high-purity products that have undergone high-temperature pretreatment), good thermal shock resistance, good processability, and can effectively isolate the direct radiation of heat flow to the vacuum chamber wall. Multiple layers can be stacked for use.

[0027] It should be noted that the sample support platform 3 is a component used to place the sample 8 to be tested. In order to facilitate the placement and fixation of the sample 8 to be tested, a groove can be provided on the side of the primary support platform 31 away from the secondary support platform 32. The width and depth of the groove can be preset according to the usage requirements, as long as it is ensured that the sample 8 to be tested can be completely placed in the groove. In this way, the position of the sample 8 to be tested can be limited by the groove wall, ensuring that the sample 8 to be tested will not be displaced during the test.

[0028] It is worth noting that, in order to better limit the movement of the sample 8 under test, the shape of the groove can be set according to the shape of the sample 8 under test. For example, when the sample 8 under test is circular, the groove is a circular groove; when the sample 8 under test is square, the groove is a square groove.

[0029] Furthermore, the sample support stage 3 is made of heat-insulating cotton felt and has a hollow structure to allow for normal heat dissipation from the back of the sample 8 under test. The use of heat-insulating cotton felt serves two purposes: firstly, it effectively blocks downward heat conduction from the sample 8 during ablation, preventing heat conduction from heating the entire device; secondly, it ensures that heat primarily acts on the surface of the sample 8, preventing heat loss and thus more realistically simulating the thermal response of materials in actual ablation environments; and thirdly, ablation tests are typically conducted at high temperatures (up to several thousand degrees Celsius), and the sample support stage 3 will directly contact the sample 8 under intense thermal shock. The high-temperature resistance of the heat-insulating cotton felt helps control the temperature of the sample support stage 3 within a safe range, reducing reliance on the cooling system and improving test safety.

[0030] It should be noted that the sizes of the primary support platform 31 and the secondary support platform 32 can be set according to the usage requirements. For example, the bottom area of the primary support platform 31 can be smaller than the top area of the secondary support platform 32. In this way, the primary support platform 31 and the secondary support platform 32 can form a structure like the Chinese character "Lv", so that technicians can quickly distinguish the primary support platform 31 and the secondary support platform 32, and then it is convenient to quickly disassemble the primary support platform 31 to place the test sample 8.

[0031] The support frame 4 is a component used to provide support force for each component, and its material and size can be set according to the size of the test sample 8. For example, it can be prepared from an alloy with higher strength and better heat resistance.

[0032] The heating lamp group 5 is a component used to provide an ablation heat environment. The heating lamp group 5 can be multiple quartz lamps, and the multiple quartz lamps are arranged in a parallel array.

[0033] It should be noted that in order to better achieve heating, the distance between the heating lamp group 5 and the test sample 8 can be set according to the requirements. For example, the distance between the heating lamp group 5 and the test sample 8 can be 60 mm, and no specific limitation is made here.

[0034] The thermocouple is a component used to measure the temperature of the test sample 8, and its quantity can be set according to the requirements. For example, in this embodiment, the number of thermocouples is 3, and one of the 3 thermocouples is connected to the heated surface of the test sample 8, and the remaining 2 thermocouples are connected to the back surface of the test sample 8. In this way, the temperature of the heated surface and the back surface of the test sample 8 can be grasped in real time through the three thermocouples.

[0035] For the test device provided in this embodiment, the specific test process is as follows: When using this test device to perform ablation performance testing, the test sample 8 can be first placed in the groove on the primary support platform 31. Then, one thermocouple is connected to the heated surface of the test sample 8, and the remaining two thermocouples pass through the inside of the primary support platform 31 and are connected to the back surface of the test sample 8. Then, the primary support platform 31 is movably connected to the secondary support platform 32. The entire device body 2 with the test sample 8 placed on it is placed into the low-pressure vacuum chamber 1. Then, the low-pressure vacuum chamber 1 is evacuated until the vacuum degree inside the low-pressure vacuum chamber 1 reaches below 3000 Pa. At this time, the heating lamp group 5 is turned on to perform heat flux ablation on the test sample 8, and the temperature of the heated surface and the back surface of the test sample 8 is detected by the thermocouple to ensure the stability of the ablation heat environment. When the ablation is completed, when the back surface temperature of the test sample 8 drops below 80 °C, the vacuum degree is turned off, and the test sample 8 is taken out after cooling. The mass ablation rate is calculated by detecting the weight of the test sample 8 after ablation, and the ablation performance of the test sample 8 is obtained by combining the heated surface temperature curve and the back temperature curve of the test sample 8.

[0036] Example 2 Based on Example 1, this embodiment also provides a structural diagram of a testing device for the ablation performance of composite materials under vacuum. The structural composition of this testing device is the same as that in Example 1, except that the device body 2, in addition to the structural composition (including connection relationships) provided in Example 1, also includes a heat flow sensor 7. The heat flow sensor 7 is positioned at the same height as the top surface of the sample support stage 3. See [link to relevant documentation]. Figure 3 .

[0037] It should be noted that the heat flow sensor 7 is a component used to monitor the internal heat flow of the device during the ablation test. The measurement range and accuracy of the heat flow sensor 7 can be preset according to usage requirements; for example, the measurement range of the heat flow sensor 7 can be 300~800 kW / m. 2 Furthermore, the measurement accuracy is less than 5%. Since the heat flow sensor 7 is positioned at the same height as the top surface of the sample support stage 3, the heat flow sensor 7 and the sample 8 under test are on the same horizontal line. Therefore, the temperature monitored by the heat flow sensor 7 is the heat flow reaching the surface of the sample 8 under test, which realizes the monitoring of the ablation thermal environment and facilitates the verification of the accuracy of the thermocouple test results.

[0038] Specifically, when using this testing device to perform ablation performance testing, the sample 8 to be tested is first placed in the groove provided on the primary support platform 31. Then, one thermocouple is connected to the heated surface of the sample 8, and the remaining two thermocouples are passed through the interior of the primary support platform 31 and connected to the back side of the sample 8. The primary support platform 31 is then movably connected to the secondary support platform 32. The entire connected device body 2 is placed into the low-pressure vacuum chamber 1, and then the low-pressure vacuum chamber 1 is evacuated until the vacuum level inside the chamber reaches below 3000 Pa. At this time, the heating lamp assembly 5 is turned on to perform thermal ablation on the sample 8. The ablation temperature on the surface of the sample 8 is monitored in real time by the heat flow sensor 7, and the heat flow of the heating lamp assembly 5 is adjusted according to the monitoring results. Thermocouples are used to detect the temperature of the heated surface and the back side of the sample 8 to ensure a stable ablation thermal environment. After ablation, when the temperature of the back side of the sample 8 drops below 80°C, the vacuum is turned off, and the sample 8 is removed after cooling. The mass ablation rate is calculated by measuring the weight of the sample 8 after ablation, and the ablation performance of the sample 8 is obtained by combining the temperature curves of the heated surface and the back surface of the sample 8.

[0039] The above description is merely a specific embodiment of this utility model, enabling those skilled in the art to understand or implement it. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this utility model.

[0040] It should be understood that this utility model is not limited to the content already described above, and various modifications and changes can be made without departing from its scope. The scope of this utility model is limited only by the appended claims.

Claims

1. A testing device for the ablation performance of composite materials under vacuum conditions, characterized in that, include: Low-pressure vacuum chamber (1) and device body (2) located inside the low-pressure vacuum chamber (1); The device body (2) includes a support frame (4), the inner wall of the support frame (4) is fixed with a heat insulation layer, a temperature sensor (6) is provided outside the support frame (4), a sample support platform (3) and a heating lamp group (5) are provided inside the support frame (4), the heating lamp group (5) is located above the sample support platform (3), a sample to be tested (8) is placed on the sample support platform (3), and the sample to be tested (8) is connected to the temperature sensor (6).

2. The testing apparatus for the ablation performance of composite materials under vacuum environment according to claim 1, characterized in that, The sample support platform (3) is set on the heat insulation layer on the bottom surface of the support frame (4), and the heating lamp group (5) is fixedly installed on the heat insulation layer on the top surface of the support frame (4).

3. The testing apparatus for the ablation performance of composite materials under vacuum environment according to claim 1, characterized in that, The temperature sensor (6) is a thermocouple.

4. The testing apparatus for the ablation performance of composite materials under vacuum environment according to claim 3, characterized in that, The number of thermocouples is three. Any one of the three thermocouples is connected to the heated surface of the sample to be tested (8), and the remaining two thermocouples are connected to the back side of the sample to be tested (8).

5. The testing apparatus for the ablation performance of composite materials under vacuum environment according to claim 1, characterized in that, It also includes a heat flow sensor (7), which is located inside the support frame (4) at a position level with the top surface of the sample support stage (3).

6. The testing apparatus for the ablation performance of composite materials under vacuum environment according to claim 1, characterized in that, The sample support platform (3) is a hollow structure, including a primary support platform (31) and a secondary support platform (32) arranged sequentially from top to bottom; the bottom surface of the secondary support platform (32) is fixedly connected to the heat insulation layer of the inner bottom surface of the support frame (4), and the bottom surface of the primary support platform (31) is movably connected to the top surface of the secondary support platform (32).

7. The testing apparatus for the ablation performance of composite materials under vacuum environment according to claim 6, characterized in that, The bottom area of ​​the primary support platform (31) is smaller than the bottom area of ​​the secondary support platform (32).

8. The testing apparatus for the ablation performance of composite materials under vacuum environment according to claim 6, characterized in that, The top surface of the primary support platform (31) is provided with a groove for placing the sample (8) to be tested.

9. The testing apparatus for the ablation performance of composite materials under vacuum environment according to claim 8, characterized in that, The groove is either circular or square.

10. The testing apparatus for the ablation performance of composite materials under vacuum environment according to claim 1, characterized in that, The heating lamp assembly (5) includes multiple quartz lamps arranged in an array.

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