Sample support for testing thermal conductivity of planetary differentiation rock powder and testing method
By combining a sample holder with a laser thermal conductivity meter, the problem of accuracy in measuring the thermal conductivity of loose planetary differentiated rock powder was solved, achieving improved measurement accuracy and repeatability while reducing sample usage.
Patent Information
- Application Number
- CN202511873497.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-12
- Publication Date
- 2026-03-03
AI Technical Summary
Existing technologies struggle to accurately measure the thermal conductivity of loose, planetary-differentiated rock powder. Traditional methods may alter the sample structure or require large sample volumes, leading to test results that deviate from reality.
Design a sample holder, including a sample base, an adjustment plate, and a cover plate. The sample thickness is adjusted by the number of adjustment plates. Sapphire material is used to ensure transmittance and detection accuracy. The thermal diffusivity is measured by combining a laser thermal conductivity meter.
This method enables accurate measurement of the thermal conductivity of loose powder while reducing the amount of sample used, ensuring the accuracy and repeatability of test results.
Smart Images
Figure CN121595644A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of thermal conductivity testing technology, and more specifically to a sample holder and testing method for testing the thermal conductivity of planetary diagenetic rock powder. Background Technology
[0002] The "2023 Research Frontiers" report released by the Chinese Academy of Sciences points out that asteroid surface characteristics and sample analysis are currently hot research frontiers in the field of Earth science. The research work on the samples returned from asteroid 2016HO3 by Tianwen-2 explicitly states the need to conduct research on the thermophysical properties of near-Earth asteroid surface materials. This research can provide scientific evidence for the characteristics of asteroid differentiation layers, the origin and evolution mechanism of asteroids, and the formation and evolution process of the early solar system.
[0003] However, the measurement of thermal conductivity of near-Earth asteroids faces significant challenges due to factors such as the loose structure of the powder on the surface, interparticle contact thermal resistance, porosity, and particle size distribution. While traditional steady-state methods (such as the hot plate method and the protective hot plate method) and transient methods (such as the hot wire method and the laser flash method) are widely used, steady-state methods require sample compaction to reduce contact thermal resistance, potentially altering the actual pore structure. The hot wire method is sensitive to particle size, leading to significant deviations. The laser flash method often requires sample compression, which may alter its true physical state, causing the test results to deviate from actual thermal conductivity behavior. Furthermore, steady-state methods require large sample volumes due to the large sensor area, making them unsuitable for testing precious samples.
[0004] Therefore, how to provide a sample holder that can easily and quickly measure the thermal conductivity of loose powder is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention
[0005] In view of this, the present invention provides a sample holder for testing the thermal conductivity of planetary differentiated rock powder, which enables adjustment of sample thickness. To achieve the above objectives, the present invention adopts the following technical solution: On one hand, this invention discloses a sample holder for testing the thermal conductivity of planetary differentiated rock powder, comprising: A sample base, wherein a placement groove is provided on the sample base, and a sample placement slot is provided in the placement groove; An adjusting plate is provided with a through hole, the shape and size of which are the same as the shape and size of the sample placement groove, and the shape and size of the adjusting plate are the same as the shape and size of the placement groove. Multiple adjusting plates are provided. During the test, multiple adjustment plates are stacked sequentially, and the through holes of the multiple adjustment plates are interconnected and all communicate with the sample placement slot.
[0006] Furthermore, it also includes a cover plate, the shape and size of which are the same as those of the placement groove. During the test, the cover plate overlaps the end of the adjustment plate that is away from the sample base.
[0007] Furthermore, the sample base is made of sapphire.
[0008] Furthermore, the adjustment plate is made of sapphire.
[0009] Furthermore, the cover plate is made of sapphire.
[0010] On the other hand, the present invention provides a test method for testing the thermal conductivity of planetary precipitated rock powder, the test method using the sample holder described above for testing the thermal conductivity of planetary precipitated rock powder, comprising the following steps: S10: Select the number of adjustment plates according to the required sample thickness, overlap the adjustment plates together, ensure that the edges of each adjustment plate are aligned, and make each through hole communicate with the sample placement slot; S20: Place the sample into the sample placement slot and through hole; S30: Use the cover plate to level the sample, making the sample flush with the end of the top adjustment plate away from the sample base, and then cover it with the cover plate. S40: Place the sample holder with the sample loaded on the sample stage of the laser thermal conductivity meter, put the instrument in, set the instrument parameters, and start measuring the thermal diffusivity of the sample; S50: Calculate the thermal conductivity based on the thermal diffusivity.
[0011] As can be seen from the above technical solution, compared with the prior art, the present invention discloses a sample holder for testing the thermal conductivity of planetary differentiated rock powder. According to the required sample thickness, the number of adjustment plates can be increased or decreased to make the sample thickness meet the testing requirements, ensuring the accuracy of the test results of the sample thermal diffusivity, thereby ensuring the accuracy of the calculation of the sample thermal conductivity. Attached Figure Description
[0012] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.
[0013] Figure 1 This is a schematic diagram of the sample base of the sample holder for testing the thermal conductivity of planetary differentiated rock powder provided by the present invention. Figure 2This is a schematic diagram of the structure of the adjustment plate of the sample holder for testing the thermal conductivity of planetary differentiated rock powder provided by the present invention. Figure 3 This is a schematic diagram of the cover plate of the sample holder for testing the thermal conductivity of planetary differentiated rock powder provided by the present invention. Figure 4 A schematic diagram showing the structure of placing the sample holder on the sample stage of the laser thermal conductivity instrument; Figure 5 The temperature rise curve and fitting graph of basalt powder with a sample thickness of 2 mm are shown. Figure 6 The temperature rise curve and fitting graph of basalt powder with a sample thickness of 1.5 mm are shown. Figure 7 The temperature rise curve and fitting graph of basalt powder with a sample thickness of 1 mm are shown.
[0014] In the diagram: 1. Sample placement slot; 2. Sample base; 3. Placement groove; 4. Adjustment plate; 5. Through hole; 6. Cover plate; 7. Laser; 8. Sample stage; 9. Infrared detector. Detailed Implementation
[0015] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0016] See Figure 1-7 This invention discloses a sample holder for testing the thermal conductivity of planetary differentiated rock powder, comprising: Sample base 2, sample base 2 is provided with placement groove 3, and sample placement slot 1 is provided in placement groove 3; Adjustment plate 4, with through holes 5 provided on it. The shape and size of the through holes 5 are the same as those of the sample placement groove 1. The shape and size of the adjustment plate 4 are the same as those of the placement groove 3. Multiple adjustment plates 4 are provided. During the test, multiple adjustment plates 4 are stacked in sequence, and the through holes 5 of the multiple adjustment plates 4 are interconnected and all communicate with the sample placement slot 1.
[0017] Based on the required sample quantity for testing, select the number of adjustment plates 4. Place one adjustment plate 4 into the placement groove 3, making the edge of the adjustment plate 4 flush with the edge of the placement groove 3. At this time, the through hole 5 is connected to the sample placement groove 1. Place the remaining adjustment plates 4 one after another on top of the adjustment plates 4 in the placement groove 3, so that multiple through holes 5 are connected to the sample placement groove 1. Multiple through holes 5 and sample placement groove 1 are connected to form a placement cavity. Place the sample powder into the placement cavity.
[0018] By increasing or decreasing the number of adjustment plates 4, the capacity of the placement chamber can be flexibly changed, ensuring the accuracy of test results while reducing the amount of sample used.
[0019] In some embodiments, a cover plate 6 is also included. The shape and size of the cover plate 6 are the same as those of the placement groove 3. During the test, the cover plate 6 overlaps the end of the adjustment plate 4 that is away from the sample base 2.
[0020] After placing the sample into the placement chamber, use the cover plate 6 to smooth the upper surface of the sample to prevent it from being blown away by the purging air during measurement, thus ensuring the accuracy of the test results.
[0021] In some embodiments, the sample base 2 is made of sapphire.
[0022] In some embodiments, the adjustment plate 4 is made of sapphire.
[0023] In some embodiments, the cover plate 6 is made of sapphire.
[0024] Table 1. Results and Standard Values of Thermal Diffusion Test for Ceramic Standards
[0025] As can be seen from the measurement results of the standard substances in Table 1, the error between the measurement results of the sapphire sample holder and the standard value is within 3%, indicating that the sapphire sample holder can be used as a sample support without affecting the accuracy of the measurement results.
[0026] By using a sapphire sample holder, the sample holder achieves extremely high transmittance across a wide wavelength range from ultraviolet to mid-infrared (approximately 0.15-5.5 μm), ensuring that the laser pulse can pass through the sample base 2 without loss and reach the sample directly. Simultaneously, it ensures that the sample's infrared radiation signal can pass through the cover plate 6 almost without loss and be accurately captured by the infrared detector, guaranteeing that the detection results are unaffected.
[0027] On the other hand, a test method for testing the thermal conductivity of planetary precipitated rock powder, the test method using the sample holder described above for testing the thermal conductivity of planetary precipitated rock powder, includes the following steps: S10: Select the number of adjustment plates 4 according to the required sample thickness, overlap the adjustment plates 4 together, ensure that the edges of each adjustment plate 4 are aligned, and make each through hole 5 communicate with the sample placement groove 1. S20: Place the sample into the sample placement slot 1 and the through hole 5; S30: Use the cover plate 6 to scrape the sample flat, so that the sample is flush with the end of the uppermost adjusting plate 4 away from the sample base 2, and then cover it with the cover plate 6. S40: Place the sample holder with the sample loaded on the sample stage 8 of the laser thermal conductivity instrument, put the instrument in, set the instrument parameters, and start testing the thermal diffusivity of the sample using the laser flash method. S50: Calculate the thermal conductivity based on the thermal diffusivity.
[0028] During the test of the thermal diffusivity of the sample, after the sample is placed in the sample stage of the instrument, the laser 7 passes through the circular hole in the center of the sample stage 8 and irradiates the bottom surface of the sample in the sample holder. Then, the infrared detector 9 above detects the temperature rise signal on the upper surface of the sample. By fitting the temperature rise curve through the standard model, the half-heating time is obtained, and the thermal diffusivity of the sample can be obtained.
[0029] Using basalt powder to simulate planetary differentiated rock powder as an example, the thermal conductivity of the sample was measured to investigate the influence of different sample thicknesses on the thermal diffusivity measurement results.
[0030] Table 2. Thermal diffusion test results for a sample with a thickness of 2 mm.
[0031] Table 3. Thermal diffusion test results for a 1.5 mm thick sample.
[0032] Table 4. Thermal diffusion test results for a sample with a thickness of 1 mm
[0033] Comparing the measurement results of the three samples with different thicknesses, it can be seen that when the sample thickness is too thick, its temperature rise curve shows obvious fluctuations and deviates significantly from the standard fitting curve, resulting in a large uncertainty deviation in the measurement results. As the sample thickness decreases, its temperature rise curve becomes smoother, the better the fit with the standard fitting curve, the better the repeatability of the corresponding thermal diffusivity result, and the smaller the uncertainty.
[0034] Measuring the thermal diffusivity of the sample using the laser flash method ensures the accuracy of the test results while reducing the amount of sample used, thus guaranteeing the accuracy of the thermal conductivity calculation.
[0035] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.
[0036] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. 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 the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A sample holder for testing the thermal conductivity of planetary differentiated rock powder, characterized in that, include: A sample base, wherein a placement groove is provided on the sample base, and a sample placement slot is provided in the placement groove; An adjusting plate is provided with a through hole, the shape and size of which are the same as the shape and size of the sample placement groove, and the shape and size of the adjusting plate are the same as the shape and size of the placement groove. Multiple adjusting plates are provided. During the test, multiple adjustment plates are stacked sequentially, and the through holes of the multiple adjustment plates are interconnected and all communicate with the sample placement slot.
2. The sample holder for testing the thermal conductivity of planetary differentiated rock powder according to claim 1, characterized in that, It also includes a cover plate, the shape and size of which are the same as those of the placement groove. During the test, the cover plate overlaps the end of the adjustment plate that is away from the sample base.
3. The sample holder for testing the thermal conductivity of planetary differentiated rock powder according to claim 1, characterized in that, The sample base is made of sapphire.
4. The sample holder for testing the thermal conductivity of planetary differentiated rock powder according to claim 1, characterized in that, The adjustment plate is made of sapphire.
5. The sample holder for testing the thermal conductivity of planetary differentiated rock powder according to claim 2, characterized in that, The cover plate is made of sapphire.
6. A test method for measuring the thermal conductivity of planetary diagenetic rock powder, characterized in that, The test method uses the sample holder for testing the thermal conductivity of planetary differentiated rock powder as described in any one of claims 1-5, and includes the following steps: S10: Select the number of adjustment plates according to the required sample thickness, overlap the adjustment plates together, ensure that the edges of each adjustment plate are aligned, and make each through hole communicate with the sample placement slot; S20: Place the sample into the sample placement slot and through hole; S30: Use the cover plate to level the sample, making the sample flush with the end of the top adjustment plate away from the sample base, and then cover it with the cover plate. S40: Place the sample holder with the sample loaded on the sample stage of the laser thermal conductivity meter, put the instrument in, set the instrument parameters, and start measuring the thermal diffusivity of the sample; S50: Calculate the thermal conductivity based on the thermal diffusivity.