A ceramic material, a method for its production and use

Abstract

The application relates to a ceramic material, a preparation method and application thereof, and belongs to the technical field of ceramic materials. The ceramic material is a solid solution of magnesium oxide and chromium oxide. The solid solution of magnesium oxide and chromium oxide has good compression resistance and high pressure transmission efficiency. Moreover, the solid solution of magnesium oxide and chromium oxide has excellent heat insulation properties, has the effect of neutron transparency, cannot be activated under neutron irradiation, and can be applied to high-temperature and high-pressure pressure transmission media for neutron diffraction.

Description

Technical Field

[0001] This application relates to the field of ceramic materials technology, and more specifically, to a ceramic material, its preparation method, and its application. Background Technology

[0002] Currently, magnesium oxide is generally used as the pressure transmission medium. However, in some high-temperature and high-pressure pressure transmission scenarios, magnesium oxide pressure transmission medium has poor thermal insulation properties, low pressure transmission efficiency, and poor sealing effect. Traditional magnesium oxide pressure transmission medium is not suitable for high-temperature and high-pressure pressure transmission processes.

[0003] To improve the sealing effect, pressure transmission efficiency, and thermal insulation performance of pressure-transmitting media, cobalt oxide-doped magnesium oxide pressure-transmitting media materials are generally used. However, due to the large amount of cobalt-containing materials currently used in the battery market, the price of cobalt-containing raw materials has risen sharply, making cobalt oxide expensive, and thus cobalt oxide-doped magnesium oxide pressure-transmitting media materials expensive as well. Moreover, cobalt oxide-doped magnesium oxide pressure-transmitting media materials have disadvantages such as complex preparation process, low density, poor thermal insulation performance, and low pressure transport efficiency, and cannot be used in the high-temperature and high-pressure pressurization module of neutron diffraction / imaging devices. Summary of the Invention

[0004] Based on the above-mentioned shortcomings, this application provides a ceramic material, its preparation method and application, in order to partially or completely improve the problem of poor performance of pressure transmission media in related technologies.

[0005] This application is implemented as follows:

[0006] In a first aspect, an example of this application provides a ceramic material that is a solid solution of magnesium oxide and chromium oxide.

[0007] In the above-mentioned process, the solid solution of magnesium oxide and chromium oxide exhibits good compressibility and high pressure transmission efficiency. Furthermore, the solid solution of magnesium oxide and chromium oxide possesses excellent thermal insulation properties and is neutron-transparent, remaining unactivated under neutron irradiation. Therefore, it can be used as a high-temperature, high-pressure transmission medium in neutron diffraction / imaging devices.

[0008] In conjunction with the first aspect, in one possible implementation, the raw materials forming the solid solution are 50-99.5% magnesium oxide and 0.5-50% chromium oxide by mass percentage.

[0009] Optionally, the raw materials forming the solid solution may be 70-99.5% magnesium oxide and 0.5-30% chromium oxide by mass percentage.

[0010] In the above-mentioned process, the raw materials for forming the solid solution are 50-99.5% magnesium oxide and 0.5-50% chromium oxide by mass percentage, which can form solid solutions with different solid solubilities in either the chromium oxide matrix or the magnesium oxide matrix.

[0011] In conjunction with the first aspect, in one possible implementation, the solid solution has a porosity of 1-50% and a density of 2.1-3.0 g / cm³. 3 .

[0012] In a second aspect, an example of this application provides a method for preparing a ceramic material, comprising:

[0013] Obtaining raw materials, including oxide powders for forming solid solutions, wherein the oxide powders are magnesium oxide powder and chromium oxide powder;

[0014] Pretreatment steps: Mix the raw materials evenly, and then press them into blanks;

[0015] Solid solution sintering step: Sinter at 600-2000℃ for 1-20h to obtain a solid solution of magnesium oxide and chromium oxide.

[0016] In the above process, a green body is prepared by mixing magnesium oxide powder and chromium oxide powder, and then sintered at 600-2000℃ for 1-20 hours to obtain a solid solution of magnesium oxide and chromium oxide. The solid solution of magnesium oxide and chromium oxide exhibits good compressibility and high pressure transmission efficiency. It also possesses excellent thermal insulation properties, is neutron transparent, and does not activate under neutron irradiation, making it suitable for use as a high-temperature, high-pressure transmission medium in neutron diffraction / imaging devices.

[0017] Furthermore, the above preparation method is simple and can produce solid solutions of magnesium oxide and chromium oxide with good pressure transmission efficiency, thermal insulation properties and neutron transparency.

[0018] In conjunction with the second aspect, in one possible implementation, the raw materials also include a treatment agent.

[0019] In conjunction with the second aspect, in one possible implementation, the treatment agent is selected from at least one of epoxy resin, glass cleaner, polyethylene, polypropylene, polystyrene, polybutene, polyvinyl chloride, polyvinyl alcohol, polyvinyl acetal, and polymethyl methacrylate.

[0020] In conjunction with the second aspect, in one possible implementation, the raw materials, by mass percentage, consist of 50%-99.5% magnesium oxide powder, 0.5%-50% chromium oxide, and no more than 30% treatment agent.

[0021] In the above-mentioned process, no more than 30% of epoxy resin, glass water, polyethylene, polypropylene, polystyrene, polybutene, polyvinyl chloride, polyvinyl alcohol, polyvinyl acetal or polymethyl methacrylate and other treatment agents are added to the raw materials. This can make the oxide powder used to form the solid solution fully mixed, increase the bonding between grains, reduce the generation of cracks in ceramic materials during sintering, and inhibit the propagation of cracks, so as to obtain a solid solution with good pressure transmission and heat insulation properties.

[0022] In conjunction with the second aspect, in one possible implementation, in the pretreatment step, the uniformly mixed raw materials are placed at 25–800°C for pre-sintering, and then the pre-sintered mixed powder is pressed into a blank.

[0023] In the above process, before performing the solution sintering step, the raw materials mixed with the treatment agent are pre-sintered at 25-800℃, which can further improve the pressure transmission performance and heat insulation performance obtained by subsequent solution sintering.

[0024] In conjunction with the second aspect, in one possible implementation, the solution sintering step involves sintering at a temperature of 1000-1500°C for 1-20 hours.

[0025] In the above process, sintering the green body at a temperature of 1000-1500℃ for 1-20 hours can yield a magnesium oxide-chromium oxide solid solution.

[0026] In a third aspect, this application provides an example of the use of a ceramic material in the preparation of thermal insulation media, pressure transmission media, X-ray diffraction media, X-ray imaging media, neutron diffraction media, and / or neutron imaging media.

[0027] In the above-mentioned implementation process, the solid solution ceramic material provided by the first aspect of this application has high pressure transmission efficiency, good thermal insulation performance and neutron transparency. It will not be activated under neutron irradiation. The solid solution ceramic material provided by the first aspect of this application can be used to prepare thermal insulation media, pressure transmission media, X-ray diffraction media, X-ray imaging media, neutron diffraction media and / or neutron imaging media. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0029] Figure 1 A schematic diagram of the preparation process of ceramic materials provided as an example in this application;

[0030] Figure 2 The XRD patterns of the ceramic materials provided in Example 1 and Comparative Example 2 of this application;

[0031] Figure 3 A photograph of the ceramic material provided in Embodiment 2 of this application;

[0032] Figure 4 This is a SEM image of the ceramic material provided in Embodiment 2 of this application. Detailed Implementation

[0033] The embodiments of this application will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are for illustrative purposes only and should not be considered as limiting the scope of this application. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0034] Currently, cobalt oxide is typically used to dope magnesium oxide to improve the pressure transmission and thermal insulation properties of pressure-transmitting media materials. However, doped magnesium oxide has drawbacks such as complex preparation process, low density, poor thermal insulation, and low pressure transport efficiency, making it unsuitable for use in high-temperature, high-pressure pressurization modules of neutron diffraction / imaging devices.

[0035] Therefore, this application provides a ceramic material of magnesium oxide and chromium oxide solid solution and its preparation method to further improve the pressure transmission performance and thermal insulation performance of the pressure transmission medium.

[0036] A solid solution is an alloy phase in which solute atoms dissolve into the solvent lattice while retaining the solvent's type. It is typically a crystal composed of atoms or molecules of other substances dissolved in a chemical matrix.

[0037] A solid solution of magnesium oxide and chromium oxide refers to a solid solution with magnesium oxide as the matrix and chromium oxide as the solute; or a solid solution with chromium oxide as the matrix and magnesium oxide as the solute.

[0038] The preparation method of the ceramic material provided in this application is described in detail below with reference to the accompanying drawings.

[0039] Please see Figure 1 The preparation methods of ceramic materials include:

[0040] S1. Obtain raw materials, including oxide powders used to form solid solutions, wherein the oxide powders are magnesium oxide powder and chromium oxide powder.

[0041] The oxide powders that form solid solutions are magnesium oxide powder and chromium oxide powder, which can form magnesium oxide-based solid solutions or chromium oxide-based solid solutions, thereby reducing the probability of introducing oxide impurities of other metals into the ceramic materials obtained subsequently.

[0042] Forming a solid solution of magnesium oxide and chromium oxide, rather than a simple mixture of magnesium oxide and chromium oxide, allows ceramic materials to possess high pressure transmission performance while also exhibiting good thermal conductivity and neutron transparency.

[0043] Furthermore, this application does not limit the specific types of magnesium oxide powder and chromium oxide powder, and relevant personnel may make corresponding adjustments as needed.

[0044] For example, this application does not limit the particle size of magnesium oxide powder. In one possible implementation, high-purity nano or micro magnesium oxide powder may be selected.

[0045] For example, this application does not limit the particle size of chromium oxide powder. In one possible implementation, high-purity nano or micro chromium oxide powder may be selected.

[0046] Furthermore, in order to reduce the probability of cracking or other defects in the ceramic material during the subsequent solution sintering step, in one possible embodiment, a treatment agent may be added to the raw materials.

[0047] For example, the treatment agent may be selected from at least one of epoxy resin, glass cleaner, polyethylene, polypropylene, polystyrene, polybutene, polyvinyl chloride, polyvinyl alcohol, polyvinyl acetal and polymethyl methacrylate.

[0048] For example, the treatment agent may be selected from epoxy resin.

[0049] For example, the treatment agent can be selected from windshield washer fluid.

[0050] For example, the treatment agent may be selected from polyvinyl alcohol.

[0051] For example, the treatment agent may be selected from polymethyl methacrylate.

[0052] Furthermore, this application does not limit the specific ratio of magnesium oxide powder, chromium oxide powder, and treatment agent in the raw materials.

[0053] In one possible embodiment, the raw material, by mass percentage, is 50%-99.5% magnesium oxide powder, 0.5%-50% chromium oxide, and no more than 30% treatment agent.

[0054] For example, the content of magnesium oxide powder can be one of 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95% or 99.5% or any combination thereof.

[0055] For example, the content of chromium oxide powder can be one of 0.5%, 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, or 50%, or any combination thereof.

[0056] For example, the content of magnesium oxide powder can be one of 0.01%, 0.05%, 0.1%, 0.15%, 0.2%, 0.5%, 1%, 5%, 10%, 15%, 20%, 25% or 30% or any combination thereof.

[0057] For example, by mass percentage, the raw material is 99.49% magnesium oxide powder, 0.5% chromium oxide and 0.01% treatment agent.

[0058] For example, by mass percentage, the raw material is 94% magnesium oxide powder, 5% chromium oxide and 1% treatment agent.

[0059] For example, by mass percentage, the raw material is 85% magnesium oxide powder, 10% chromium oxide and 5% treatment agent.

[0060] For example, by mass percentage, the raw material is 75% magnesium oxide powder, 20% chromium oxide and 5% treatment agent.

[0061] For example, by mass percentage, the raw material is 60% magnesium oxide powder, 30% chromium oxide and 10% treatment agent.

[0062] For example, by mass percentage, the raw material is 50% magnesium oxide powder, 45% chromium oxide and 5% treatment agent.

[0063] For example, the raw material is 50% magnesium oxide powder and 50% chromium oxide by mass percentage.

[0064] For further information, please refer to [link / reference]. Figure 1 The preparation method provided in this application also includes:

[0065] S2. Pre-treatment steps: Mix the raw materials evenly and then press them into blanks.

[0066] The raw materials are mixed evenly and then pressed into a blank to facilitate the formation of a solid solution of magnesium oxide and chromium oxide during subsequent solution sintering.

[0067] This application does not restrict how the raw materials are mixed evenly; relevant personnel may make corresponding adjustments as needed.

[0068] For example, the weighed raw materials are placed in a ball mill, mixer or mortar and mixed thoroughly.

[0069] Furthermore, before pressing the uniformly mixed raw materials, the pretreatment step may also include:

[0070] S201, Pre-sintering steps

[0071] The uniformly mixed raw materials are pre-sintered at 25–800°C.

[0072] Adding activating agents to the raw materials to revitalize magnesium oxide and chromium oxide powders can make the powders more uniformly dispersed and increase the bonding between grains. To reduce the content of impurities other than solid solutions in ceramic materials, the uniformly mixed raw materials are pre-sintered at temperatures of 25-800℃ to remove impurities.

[0073] For example, the uniformly mixed raw materials can be pre-sintered for 30 minutes within a temperature range of 25°C, 50°C, 100°C, 150°C, 200°C, 250°C, 300°C, 350°C, 400°C, 450°C, 500°C, 550°C, 600°C, 650°C, 700°C, 750°C, or 800°C, or any two of these temperatures.

[0074] Furthermore, the pre-sintered powder can be granulated.

[0075] Furthermore, the granulated powder can be sieved.

[0076] This application does not limit the distance particle size of the powder after sieving. For example, the particle size of the sieved mixed powder can be one of or any two of 0.01μm, 0.05μm, 0.1μm, 0.2μm, 0.5μm, 1μm, 5μm, 10μm, 100μm, 500μm, 1000μm, 5000μm or 10000μm.

[0077] Furthermore, this application does not limit the pressure level; relevant personnel can make appropriate selections as needed.

[0078] This application does not limit the pressing pressure. For example, a pressure of 10 MPa to 1000 MPa can be applied to the powder to press it into a green body.

[0079] Furthermore, this application does not restrict how the blank is pressed; relevant personnel can make the desired selection as needed.

[0080] For example, pre-compression molding can be performed using an isostatic press, a tablet press, or any molding machinery.

[0081] For further information, please refer to [link / reference]. Figure 1 The preparation method provided in this application also includes:

[0082] S3, Solution Sintering Step

[0083] Sintering at 600-2000℃ for 1-20 hours yields a solid solution of magnesium oxide and chromium oxide.

[0084] This application does not limit the specific sintering temperature; relevant personnel can make the appropriate selection based on requirements such as solid solubility or sintering density.

[0085] For example, the sintering temperature can be one or a range of any two of the following: 600°C, 700°C, 800°C, 900°C, 1000°C, 1100°C, 1200°C, 1300°C, 1400°C, 1500°C, 1600°C, 1700°C, 1800°C, 1900°C, or 2000°C.

[0086] Furthermore, this application does not limit the specific sintering time, and relevant personnel can make corresponding adjustments as needed.

[0087] For example, the sintering time can be one or a range between any two of 1h, 2h, 3h, 4h, 5h, 20h, 6h, 7h, 8h, 9h, 10h, 11h, 12h, 13h, 14h, 15h, 16h, 17h, 18h, 19h or 20h.

[0088] For example, sintering can be performed at 600°C for 20 hours.

[0089] For example, sintering can be performed at 2000°C for 1 hour.

[0090] For example, sintering can be performed at 1800°C for 2 hours.

[0091] For example, sintering can be performed at 1700°C for 5 hours.

[0092] Furthermore, this application does not limit the specific heating process, and relevant personnel can make corresponding adjustments as needed.

[0093] In one possible implementation, the temperature can be increased to 600-2000°C at a heating rate of 0.01-30°C / s.

[0094] For example, the heating rate can be one or a range between any two of 0.01℃ / s, 0.05℃ / s, 0.1℃ / s, 0.5℃ / s, 1℃ / s, 5℃ / s, 10℃ / s, 15℃ / s, 20℃ / s, 25℃ / s, and 30℃ / s.

[0095] Furthermore, this application does not limit the specific cooling process after sintering is completed, and relevant personnel can make corresponding adjustments as needed.

[0096] In one possible implementation, the temperature can be reduced to room temperature at a rate of 0.01-30°C / s.

[0097] For example, the cooling rate can be one or a range between any two of 0.01℃ / s, 0.05℃ / s, 0.1℃ / s, 0.5℃ / s, 1℃ / s, 5℃ / s, 10℃ / s, 15℃ / s, 20℃ / s, 25℃ / s, and 30℃ / s.

[0098] Furthermore, this application does not limit the specific sintering equipment; relevant personnel may choose accordingly based on their needs.

[0099] For example, the sintering apparatus for high-temperature sintering is any variant of a heating furnace, a heat treatment furnace, a calcining furnace, or a drying and baking furnace.

[0100] The density of the magnesium oxide and chromium oxide solid solution ceramic material prepared using the above method can be 2.1 g / cm³. 3 2.2g / cm 3 2.3g / cm 3 2.4g / cm 3 2.5g / cm 3 2.6g / cm 3 2.7g / cm 3 2.8g / cm 3 Or 3.0g / cm 3 The range between one or any two of them.

[0101] The porosity of the magnesium oxide and chromium oxide solid solution ceramic material prepared by the above preparation method can be one of 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45% or 50% or any combination thereof.

[0102] The grain size of the magnesium oxide and chromium oxide solid solution ceramic material prepared by the above preparation method can be one of 0.01 μm, 0.05 μm, 0.1 μm, 0.2 μm, 0.5 μm, 1 μm, 5 μm, 10 μm, 200 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm or 200 μm or any combination thereof.

[0103] Furthermore, this application also provides a pressure-transmitting medium, which is prepared from a ceramic material obtained by the above preparation method.

[0104] The pressure-transmitting medium provided in this application example has good pressure transmission and thermal insulation properties, and can be used in high-temperature environments. For example, it can be used in pressure gauges.

[0105] Furthermore, this application also provides a heat insulation medium prepared from ceramic materials obtained by the above preparation method.

[0106] The insulation medium provided in this application example can be used for heat insulation in high-temperature environments. For example, it can be used in the furnace body of a high-temperature furnace. Furthermore, this application also provides a neutron diffraction medium and / or a neutron imaging medium, which is prepared from ceramic materials obtained by the above-described preparation method.

[0107] The neutron diffraction medium and / or neutron imaging medium provided in this application have good neutron transparency, minimal neutron absorption and blocking, and will not activate or harm the detected organism after irradiation. For example, it can be applied to high-temperature and high-pressure loading devices for neutron diffraction.

[0108] Furthermore, this application also provides an X-ray diffraction and / or imaging medium, which is prepared from a ceramic material obtained by the above preparation method.

[0109] For example, it can be applied to the cavity of an X-ray diffractometer.

[0110] The ceramic material of this application will be further described in detail below with reference to the embodiments.

[0111] Example 1

[0112] Example 1 provides a ceramic material, the preparation method of which is as follows:

[0113] (1) Raw material preparation: Weigh 85 parts of magnesium oxide powder and 15 parts of chromium oxide powder. See Table 1 for specific composition.

[0114] (2) Pretreatment: The raw materials from step (1) are mixed using a high-energy ball mill, and the mixed powder after uniform mixing is pressed into a blank.

[0115] (3) Solid solution sintering: The blank from step (2) is sintered at 1200℃ for 5 hours to obtain a solid solution of magnesium oxide and chromium oxide.

[0116] Example 2

[0117] Example 2 provides a ceramic material, which differs from Example 1 in that:

[0118] (1) Raw material preparation: Weigh 85 parts of magnesium oxide powder, 15 parts of chromium oxide powder, and 5 parts of treatment agent. The treatment agent is selected from polyvinyl chloride. See Table 1 for specific components.

[0119] Example 3

[0120] Example 3 provides a ceramic material that differs from Example 2 in that:

[0121] In step (2), the mixed powder is pre-sintered at a temperature of 230°C; the pre-sintered powder is then pressed into a blank. See Table 1 for the specific composition.

[0122] Comparative Example 1

[0123] Comparative Example 1 provides a ceramic material, which differs from Example 1 in that in step (1), (1) raw material preparation: 85 parts of magnesium oxide powder, 5 parts of chromium oxide powder and 10 parts of cobalt oxide are weighed. See Table 1 for the specific composition.

[0124] Comparative Example 2

[0125] Comparative Example 2 provides a ceramic material that differs from Example 1 in that:

[0126] In step (1), (1) raw material preparation: weigh 85 parts of magnesium oxide powder, 7 parts of chromium oxide powder, 4 parts of iron oxide and 4 parts of titanium oxide.

[0127] See Table 1 for specific ingredients.

[0128] Table 1

[0129] serial number magnesium oxide Chromium oxide Treatment cobalt oxide iron oxide Titanium oxide Example 1 85 15 - - - - Example 2 85 15 5 - - - Example 3 85 15 5 - - - Comparative Example 1 85 5 - 10 - - Comparative Example 2 85 7 - - 4 4

[0130] Test case

[0131] XRD analysis was performed on the mixed powder before sintering and the product after sintering in Example 1, and on the mixed powder before sintering and the product after sintering in Comparative Example 2. The test results are as follows: Figure 2 As shown.

[0132] Morphological analysis was performed on the ceramic material provided in Example 2. A photograph of the ceramic material provided in Example 2 is shown below. Figure 3 As shown, the SEM image of the ceramic material provided in Example 2 is as follows. Figure 4 As shown.

[0133] The pressure transmission performance and thermal conductivity of the ceramic materials provided in Examples 1-3 and Comparative Examples 1-2 were tested, and the test results are shown in Table 2. The pressure transmission performance was tested by pressing a tungsten carbide cube with an 8mm truncated angle against a 14mm side length of the test sample, calibrating the pressure, and obtaining the test data. For example, 170T / 9GPa in the test data indicates that the applied force was 170 tons at a calibrated pressure of 9GPa.

[0134] Table 2

[0135] serial number Porosity % Pressure transmission performance Thermal conductivity (W / m·K) Example 1 36 170T / 9GPa 6.2 Example 2 34 168T / 9GPa 5.5 Example 3 32 166T / 9GPa 5.1 Comparative Example 1 28 205T / 9GPa 7.5 Comparative Example 2 26 210T / 9GPa 15

[0136] Results Analysis: Figure 2It can be seen that the ceramic material provided in this application is a solid solution of magnesium oxide and chromium oxide, while a solid solution cannot be formed in Comparative Example 2. From... Figure 3 and Figure 4 It can be seen that treating magnesium oxide and chromium oxide powders with a conditioning agent can form a dense, virtually crack-free ceramic material after subsequent solution sintering. Combined with Examples 1-3, it can be seen that the conditioning agent can improve the pressure transmission performance of the ceramic material.

[0137] Comparing Example 1 and Comparative Examples 1-2, it can be seen that the magnesium oxide-chromium oxide solid solution provided in this application has good pressure transmission performance and low thermal conductivity (good heat preservation performance).

[0138] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for preparing a ceramic material, characterized in that, include: Obtaining raw materials; The raw material, by mass percentage, comprises 50%-99.5% magnesium oxide powder, 0.5%-50% chromium oxide, and 0.01%-30% physical treatment agent; the physical treatment agent is polyvinyl chloride. Pretreatment step: Mix the raw materials evenly, and then press them into a blank; Solid solution sintering step: Sinter at 600-2000 ℃ for 1-20 h to obtain a solid solution of magnesium oxide and chromium oxide.

2. The preparation method according to claim 1, characterized in that, In the pretreatment step, the uniformly mixed raw materials are placed at 25~800 ℃ for pre-sintering, and then the pre-sintered mixed powder is pressed into a green body.

3. The preparation method according to claim 1 or 2, characterized in that, In the solution sintering step, sintering is carried out at a temperature of 1000-1500 °C for 1-20 h.

4. A ceramic material, characterized in that, Prepared by the preparation method according to any one of claims 1 to 3.

5. The ceramic material according to claim 4, characterized in that, The ceramic material has a porosity of 1-50% and a density of 2.1-3.0 g / cm³. 3 .

6. The use of the ceramic material according to claim 4 or 5 in the preparation of thermal insulation media, pressure transmission media, X-ray diffraction media, X-ray imaging media, neutron diffraction media and / or neutron imaging media.

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