A ternary high-temperature ceramic material, its preparation method and application

Abstract

The present invention provides a ternary high-temperature ceramic material, the chemical composition of which, by mass percentage, includes: 43-60% of TiB2, 36-52% of TiN, and 1-15% of SiC. In the present invention, TiN is an electromagnetic wave absorption material with a high melting point, high dielectric loss, and unique electromagnetic behavior, which can further improve the wave absorption performance of TiB2. At the same time, TiB2 can make up for the deficiencies of TiN in effective absorption bandwidth and weak absorption ability; SiC and TiN can form a dielectric loss type microwave absorption material in combination with TiB2, thereby enhancing the microwave absorption performance of TiB2.

Description

Technical Field

[0001] The present invention relates to the technical field of high-temperature composite ceramic materials, and particularly relates to a ternary high-temperature ceramic material, a preparation method thereof, and an application thereof. Background Art

[0002] Microwave absorption materials have attracted more and more attention in aspects such as aerospace, medical technology, and communication security. Due to their unique material properties, microwave absorption materials can reduce or prevent reflection by absorbing incident waves, thereby reducing the impact of electromagnetic radiation. In recent years, the design of more and more microwave absorption material systems and structures has been widely studied.

[0003] TiB₂ has excellent properties such as a high melting point (3225 °C), high electrical conductivity, high melting point, high hardness, and high temperature resistance, and has become one of the emerging transition metal boride ceramics in recent years. Its strong high-temperature stability and low density make it a microwave absorption material with high-temperature application prospects. However, its microwave absorption performance is low and it is difficult to meet the application requirements. Therefore, how to improve the microwave absorption performance of ceramic materials has become an urgent technical problem in this field. Summary of the Invention

[0004] The purpose of the present invention is to provide a ternary high-temperature ceramic material, a preparation method thereof, and an application thereof. The ternary high-temperature ceramic material provided by the present invention has excellent microwave absorption performance.

[0005] In order to achieve the above-mentioned invention purpose, the present invention provides the following technical solutions:

[0006] The present invention provides a ternary high-temperature ceramic material, and its chemical components by mass percentage include: 43-60% of TiB₂, 36-52% of TiN, and 1-15% of SiC.

[0007] Preferably, the chemical components by mass percentage include: 44.4-54.6% of TiB₂, 41.5-50.8% of TiN, and 3.6-4.8% of SiC.

[0008] Preferably, the chemical components by mass percentage include: 54.3% of TiB₂, 41.5% of TiN, and 4.2% of SiC.

[0009] Preferably, the TiB₂ is hexagonal flake-shaped, the side length of the hexagonal flake is 1-2 μm, and the thickness of the hexagonal flake is 0.1-0.3 μm.

[0010] Preferably, the TiN is hexagonal flake-shaped, the side length of the hexagonal flake is 0.5-2 μm, and the thickness of the hexagonal flake is 0.1-0.2 μm.

[0011] Preferably, the SiC is spherical particles with a diameter of 0.1 - 0.5 μm.

[0012] The present invention also provides a method for preparing the ternary high-temperature ceramic material described in the above technical solution, comprising the following steps:

[0013] (1) Mix tetrabutyl titanate, tetraethyl orthosilicate, hydrochloric acid, water, an emulsifier, and ethanol to obtain a first mixed solution;

[0014] (2) Mix sodium tetraborate, sucrose, and water to obtain a second mixed solution;

[0015] (3) Mix the first mixed solution obtained in step (1) and the second mixed solution obtained in step (2), and carry out a sol-gel reaction to obtain a sol;

[0016] (4) Age, dry, and calcine the sol obtained in step (3) in sequence to obtain a precursor;

[0017] (5) Carry out a borothermal reduction reaction on the precursor obtained in step (4) in a nitrogen atmosphere or successively in argon and nitrogen atmospheres to obtain a ternary high-temperature ceramic material;

[0018] There is no sequence requirement between step (1) and step (2).

[0019] Preferably, the calcination temperature in step (4) is 200 - 400 °C, and the calcination time is 0.5 - 2 h.

[0020] Preferably, the temperature of the borothermal reduction reaction in step (5) is 1000 - 1500 °C, and the time of the borothermal reduction reaction is 0.5 - 2.5 h.

[0021] The present invention also provides the application of the ternary high-temperature ceramic material described in the above technical solution or the ternary high-temperature ceramic material prepared by the preparation method described in the above technical solution in aerospace devices.

[0022] The present invention provides a ternary high-temperature ceramic material, the chemical composition of which, by mass percentage, includes: 43-60% of TiB2, 36-52% of TiN, and 1-15% of SiC. In the present invention, TiN is a high melting point electromagnetic wave absorption material with high dielectric loss and unique electromagnetic behavior, which can further improve the wave absorption performance of the TiB2 material. At the same time, TiB2 can make up for the deficiencies of TiN in effective absorption bandwidth and weak absorption ability; SiC and TiN can form a dielectric loss type microwave absorption material in combination with TiB2, thereby enhancing the microwave absorption performance of TiB2. The experimental results show that the maximum reflection loss of the ternary high-temperature ceramic material provided by the present invention is between -13.09 and -30.93 dB, and the effective absorption bandwidth can cover the X and Ku bands. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 XRD patterns of the ternary high-temperature ceramic materials prepared in Examples 1-3;

[0024] Figure 2 SEM images of the ternary high-temperature ceramic material prepared in Example 1;

[0025] Figure 3 XPS spectra of the ternary high-temperature ceramic material prepared in Example 1;

[0026] Figure 4 Microwave absorption spectra of the ternary high-temperature ceramic material prepared in Example 1;

[0027] Figure 5 Microwave absorption spectra of the ternary high-temperature ceramic material prepared in Example 2;

[0028] Figure 6 Microwave absorption spectra of the ternary high-temperature ceramic material prepared in Example 3. DETAILED DESCRIPTION OF THE INVENTION

[0029] The present invention provides a ternary high-temperature ceramic material, the chemical composition of which, by mass percentage, includes: 43-60% of TiB2, 36-52% of TiN, and 1-15% of SiC.

[0030] By mass percentage, the ternary high-temperature ceramic material provided by the present invention includes 43-60% of TiB2, preferably 44.4-54.6%, more preferably 54.3%. In the present invention, the TiB2 is preferably hexagonal flake-shaped; the side length of the hexagonal flake is preferably 1-2 μm; the thickness of the hexagonal flake is preferably 0.1-0.3 μm. In the present invention, there are rich interfaces between the flake structure of TiB2 and the particles of SiC, and an interlocking structure appears between the flake structures due to different growth orientations, thereby enhancing the microwave absorption performance of the ceramic material.

[0031] By mass percentage, the ternary high-temperature ceramic material provided by the present invention further comprises 36-52% of TiN, preferably 41.5-50.8%, and more preferably 41.5%. In the present invention, the TiN is preferably hexagonal flake-shaped; the side length of the hexagonal flake is preferably 0.5-2 μm; the thickness of the hexagonal flake is preferably 0.1-0.2 μm. In the present invention, there are rich interfaces between the flake structure of TiN and the particles of SiC, and an interlocking structure appears between the flake structures due to different growth orientations, thereby enhancing the microwave absorption performance of the ceramic material.

[0032] By mass percentage, the ternary high-temperature ceramic material provided by the present invention further comprises 1-15% of SiC, preferably 3.6-4.8%, and more preferably 4.2%. In the present invention, the SiC is preferably spherical particles; the diameter of the spherical particles is preferably 0.1-0.5 μm. In the present invention, there are rich interfaces between the particles of SiC and the flake structure of TiN, thereby enhancing the microwave absorption performance of the ceramic material.

[0033] In the present invention, TiN is an electromagnetic wave absorption material with a high melting point, high dielectric loss, and unique electromagnetic behavior, which can further improve the wave absorption performance of the TiB2 material. At the same time, TiB2 can make up for the defects of insufficient effective absorption bandwidth and weak absorption ability of TiN; SiC and TiN can form a dielectric loss type microwave absorption material in combination with TiB2, thereby enhancing the microwave absorption performance of TiB2.

[0034] The ternary high-temperature ceramic material of the present invention has rich contact interfaces and a flake interlocking structure, which can enhance its microwave absorption performance and has good microwave absorption performance in the X and Ku bands at 4-5.5 mm.

[0035] The maximum reflection loss of the ternary high-temperature ceramic material provided by the present invention is between -13.09 and -30.93 dB, and the effective absorption bandwidth can cover the X and Ku bands; the melting point of TiB2 in the high-temperature ceramic material of the present invention is 2980 °C, the melting point of TiN is 2950 °C, and the melting point of SiC is 2700 °C, all exceeding 2500 °C. Therefore, the material has a high melting point and is expected to be used as a material for enhancing microwave absorption in aerospace devices.

[0036] The present invention also provides a preparation method of the ternary high-temperature ceramic material described in the above technical solution, comprising the following steps:

[0037] (1) Mix tetrabutyl titanate, tetraethyl orthosilicate, hydrochloric acid, water, an emulsifier, and ethanol to obtain a first mixed solution;

[0038] (2) Mix sodium tetraborate, sucrose, and water to obtain a second mixed solution;

[0039] (3) Mix the first mixed solution obtained in step (1) and the second mixed solution obtained in step (2), and carry out a sol-gel reaction to obtain a sol.

[0040] (4) Age, dry, and calcine the sol obtained in step (3) in sequence to obtain a precursor.

[0041] (5) Carry out a boron carbide thermal reduction reaction on the precursor obtained in step (4) in a nitrogen atmosphere or in an argon and nitrogen atmospheres in sequence to obtain a ternary high-temperature ceramic material.

[0042] There is no order of priority between step (1) and step (2).

[0043] The present invention has no special limitation on the sources of the raw materials, and commercially available products well-known to those skilled in the art or well-known preparation methods can be used.

[0044] The present invention mixes tetrabutyl titanate, tetraethyl orthosilicate, hydrochloric acid, water, an emulsifier, and ethanol to obtain a first mixed solution.

[0045] In the present invention, the hydrochloric acid is preferably concentrated hydrochloric acid; the concentration of the concentrated hydrochloric acid is preferably 2 mol / L. The hydrochloric acid in the present invention is used to adjust the pH value of the solution so as to generate a sol. The present invention has no special limitation on the dosage of the hydrochloric acid, as long as the pH value of the first mixed solution is adjusted to the range of 1-2.

[0046] In the present invention, the emulsifier is preferably polyethylene glycol; the mass of the emulsifier is preferably 0.5-3% of the total mass of tetrabutyl titanate, tetraethyl orthosilicate, sucrose, and sodium tetraborate. The emulsifier in the present invention can limit the growth of sol particles themselves, intensify the aggregation and crosslinking of "clusters", and play a "guiding" role in the growth process of the "clusters".

[0047] The present invention has no special limitation on the dosages of water and ethanol, as long as the raw materials can be dissolved. In the present invention, both water and ethanol are solvents, water is the solvent of the aqueous phase, and ethanol is the solvent of the oil phase.

[0048] In the present invention, the operation of mixing tetrabutyl titanate, tetraethyl orthosilicate, hydrochloric acid, water, an emulsifier, and ethanol is preferably to mix hydrochloric acid, water, an emulsifier, and ethanol, and then add tetrabutyl titanate and tetraethyl orthosilicate.

[0049] The present invention has no special limitation on the operation of mixing the hydrochloric acid, water, an emulsifier, and ethanol, and the technical solutions for preparing a mixed material well-known to those skilled in the art can be used.

[0050] In the present invention, the temperature for adding tetrabutyl titanate and tetraethyl orthosilicate is preferably 50 to 65 °C. The present invention has no special limitation on the time for mixing tetrabutyl titanate and tetraethyl orthosilicate, and it can be dissolved.

[0051] The present invention mixes sodium tetraborate, sucrose and water to obtain a second mixed solution.

[0052] The present invention has no special limitation on the amount of water used, as long as it can ensure that the raw materials are completely dissolved.

[0053] In the present invention, the mass ratio of tetrabutyl titanate, tetraethyl orthosilicate, sodium tetraborate and sucrose is preferably (40% - 45%):(10% - 15%):(20% - 25%):(20% - 25%), more preferably 43%:11%:24%:22%.

[0054] In the present invention, the temperature for mixing is preferably 60 to 80 °C. The present invention has no special limitation on the mixing time, as long as it can ensure that the raw materials are mixed evenly.

[0055] After obtaining the first mixed solution and the second mixed solution, the present invention mixes the first mixed solution and the second mixed solution to carry out a sol-gel reaction to obtain a sol.

[0056] In the present invention, the mixing of the first mixed solution and the second mixed solution is preferably to drop the second mixed solution into the first mixed solution. The present invention has no special limitation on the dropping rate, and the dropping rate well-known to those skilled in the art can be adopted. The dropping method adopted by the present invention can control the reaction speed and ensure sufficient reaction.

[0057] In the present invention, the temperature of the sol-gel reaction is preferably 50 to 80 °C, more preferably 60 °C; the time of the sol-gel reaction is preferably 1 to 2 h; the sol-gel reaction is preferably carried out under magnetic stirring conditions. The present invention has no special limitation on the operation of magnetic stirring, and the operation well-known to those skilled in the art can be adopted. The present invention can improve the reaction degree by controlling the temperature and time of the sol-gel reaction.

[0058] After obtaining the sol, the present invention ages, dries and calcines the sol in sequence to obtain a precursor.

[0059] In the present invention, the aging time is preferably 5 to 18 h, more preferably 12 to 15 h; the aging temperature is preferably 25 °C. Aging adopted by the present invention can turn the sol into a wet gel and can obtain a precipitate with complete crystal form, large particle size and purity.

[0060] In the present invention, the drying temperature is preferably 60 to 80 °C; the drying time is preferably 24 to 48 h, more preferably 30 to 36 h.

[0061] In the present invention, the calcination temperature is preferably 200 to 400 °C, more preferably 250 to 300 °C; the calcination time is preferably 0.5 to 2 h, more preferably 1 to 1.5 h; the calcination is preferably carried out in a muffle furnace. The present invention has no special limitation on the model of the muffle furnace, and the instruments and equipment well-known to those skilled in the art can be used. The present invention can remove crystal water by calcination; and can carbonize sucrose into C elemental substance.

[0062] After the calcination is completed, the present invention preferably mills the product obtained by the calcination to obtain a precursor.

[0063] In the present invention, the milling is preferably carried out in a planetary ball mill. The present invention has no special limitation on the model of the planetary ball mill, and the instruments and equipment well-known to those skilled in the art can be used.

[0064] In the present invention, the milling time is preferably 5 h; the milling speed is preferably 400 r / min.

[0065] After obtaining the precursor, the present invention carries out a boron-carbon thermal reduction reaction on the precursor in a nitrogen atmosphere or successively in an argon and nitrogen atmosphere to obtain a ternary high-temperature ceramic material.

[0066] After obtaining the precursor, the present invention carries out a boron-carbon thermal reduction reaction on the precursor in a nitrogen atmosphere to obtain a ternary high-temperature ceramic material.

[0067] In the present invention, the temperature of the boron-carbon thermal reduction reaction is preferably 1000 to 1500 °C, more preferably 1200 to 1500 °C; the time of the boron-carbon thermal reduction reaction is preferably 0.5 to 2.5 h, more preferably 1 to 2 h. The present invention can further improve the reaction degree by controlling the process parameters of the boron-carbon thermal reduction reaction.

[0068] In the present invention, the boron-carbon thermal reduction reaction is preferably carried out in a tube furnace. The present invention has no special limitation on the model of the tube furnace, and the instruments and equipment well-known to those skilled in the art can be used.

[0069] In the present invention, the rate of rising to the temperature of the boron-carbon thermal reduction reaction is preferably 5 to 10 °C / min, more preferably 8 °C / min.

[0070] In the present invention, the purity of the nitrogen is preferably 99.999%. The present invention carries out a boron-carbon thermal reduction reaction (nitridation reaction) in a nitrogen atmosphere to generate TiN.

[0071] After obtaining the precursor, the present invention conducts a boron-carbon thermal reduction reaction on the precursor in an argon and nitrogen atmosphere in sequence to obtain a ternary high-temperature ceramic material.

[0072] In the present invention, the temperature of the boron-carbon thermal reduction reaction of the precursor in an argon atmosphere is preferably 1000-1500 °C, more preferably 1200-1500 °C; the time of the boron-carbon thermal reduction reaction of the precursor in an argon atmosphere is preferably 0.5-2.5 h, more preferably 1-2 h.

[0073] In the present invention, the rate of heating up to the temperature of the boron-carbon thermal reduction reaction is preferably 5-10 °C / min, more preferably 8 °C / min.

[0074] In the present invention, the temperature of the boron-carbon thermal reduction reaction in a nitrogen atmosphere is preferably 300-1500 °C, more preferably 300-500 °C; the time of the boron-carbon thermal reduction reaction in a nitrogen atmosphere is preferably 0.5-6 h, more preferably 2-6 h.

[0075] In the present invention, the purity of the argon atmosphere is preferably 99.999%.

[0076] In the present invention, the boron-carbon thermal reduction reaction is preferably carried out in a tube furnace. The present invention has no special limitation on the model of the tube furnace, and the instruments and equipment well-known to those skilled in the art can be used.

[0077] In the present invention, the purity of the nitrogen is preferably 99.999%. In the present invention, TiN is formed by carrying out a boron-carbon thermal reduction reaction (nitridation reaction) in a nitrogen atmosphere.

[0078] The present invention uses tetrabutyl titanate, tetraethyl orthosilicate, sodium tetraborate, and sucrose as raw materials to obtain a precursor by a sol-gel method. The steps are simple and the cost is low. Mixing and reacting in a liquid form can achieve uniform mixing and distribution of TiB2, SiC, and TiN; by introducing nitrogen to carry out a nitridation reaction, the cost is low.

[0079] The present invention also provides the application of the ternary high-temperature ceramic material described in the above technical solution or the ternary high-temperature ceramic material prepared by the preparation method described in the above technical solution in aerospace devices.

[0080] The present invention has no special limitation on the operation of the application of the ternary high-temperature ceramic material in aerospace devices, and the application operations well-known to those skilled in the art can be used.

[0081] Next, the technical solutions of the present invention will be clearly and completely described in conjunction with the embodiments of the present invention. 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.

[0082] Embodiment 1

[0083] The ternary high-temperature ceramic material has the following chemical composition by mass percentage: 54.3% of TiB2, 41.5% of TiN, and 4.2% of SiC;

[0084] The TiB2 is in the form of hexagonal flakes, the side length of the hexagonal flakes is 1 - 2 μm, and the thickness of the hexagonal flakes is 0.1 - 0.3 μm.

[0085] The TiN is in the form of hexagonal flakes, the side length of the hexagonal flakes is 0.5 - 2 μm, and the thickness of the hexagonal flakes is 0.1 - 0.2 μm.

[0086] The SiC is in the form of spherical particles, and the diameter of the spherical particles is 0.1 - 0.5 μm;

[0087] The preparation method of the ternary high-temperature ceramic material comprises the following steps:

[0088] (1) Dissolve 39.1708 g of tetrabutyl titanate and 10.4165 g of tetraethyl orthosilicate in 400 mL of ethanol containing 9.45 mL of 2 mol / L concentrated hydrochloric acid, 250 mL of water, and 2 g of polyethylene glycol, and heat in a water bath at 60°C to obtain a first mixed solution;

[0089] (2) Dissolve 21.9478 g of sodium tetraborate and 20.6949 g of sucrose in water at 80°C to obtain a second mixed solution; wherein, the mass ratio of tetrabutyl titanate:tetraethyl orthosilicate:sodium tetraborate:sucrose is 43%:11%:24%:22%;

[0090] (3) Drop the second mixed solution obtained in step (2) into the first mixed solution, and carry out a sol-gel reaction for 1 h under magnetic stirring at 60°C to obtain a sol;

[0091] (4) Subject the sol obtained in step (3) to aging, drying, and calcination in sequence, and then use a polytetrafluoroethylene ball milling tank and agate balls as ball milling media, and ball mill on a planetary ball mill at a rotation speed of 400 r / min for 5 h to obtain a precursor; wherein, the aging time is 12 h, the aging temperature is 25°C; the drying temperature is 80°C, and the drying time is 48 h; the calcination temperature is 300°C, and the calcination time is 1 h;

[0092] (5) Put the precursor obtained in step (4) into a crucible and raise the temperature to 1500 °C at a heating rate of 8 °C / min. First, keep it at a constant temperature for 1 h under an argon atmosphere with a flow rate of 100 ml / min, and then keep it at a constant temperature for 2 h under a nitrogen atmosphere with a flow rate of 100 mL / min to carry out the boron-carbon thermal reduction reaction to obtain a ternary high-temperature ceramic material; among them, the purity of both nitrogen and argon is 99.999%.

[0093] Example 2

[0094] The ternary high-temperature ceramic material has the following chemical composition by mass percentage: 44.4% of TiB₂, 50.8% of TiN, and 4.8% of SiC;

[0095] The TiB₂ is in the shape of hexagonal flakes, the side length of the hexagonal flakes is 1 - 2 μm, and the thickness of the hexagonal flakes is 0.1 - 0.3 μm.

[0096] The TiN is in the shape of hexagonal flakes, the side length of the hexagonal flakes is 0.5 - 2 μm, and the thickness of the hexagonal flakes is 0.1 - 0.2 μm.

[0097] The SiC is in the shape of spherical particles, and the diameter of the spherical particles is 0.1 - 0.5 μm;

[0098] The preparation method of the ternary high-temperature ceramic material comprises the following steps:

[0099] (1) Dissolve 39.1708 g of tetrabutyl titanate and 10.4165 g of tetraethyl orthosilicate in 400 mL of ethanol containing 9.45 mL of 2 mol / L concentrated hydrochloric acid, 250 mL of water, and 2 g of polyethylene glycol, and heat it in a water bath at 60 °C to obtain a first mixed solution;

[0100] (2) Dissolve 21.9478 g of sodium tetraborate and 20.6949 g of sucrose in water at 80 °C to obtain a second mixed solution; among them, the mass ratio of tetrabutyl titanate:tetraethyl orthosilicate:sodium tetraborate:sucrose is 43%:11%:24%:22%;

[0101] (3) Drop the second mixed solution obtained in step (2) into the first mixed solution, and carry out a sol-gel reaction for 1 h under magnetic stirring at 60 °C to obtain a sol;

[0102] (4) The sol obtained in step (3) is subjected to aging, drying, and calcination in sequence, and then using a polytetrafluoroethylene ball milling tank and agate balls as ball milling media, ball mill it on a planetary ball mill at a rotation speed of 400 r / min for 5 h to obtain a precursor; among them, the aging time is 12 h, and the aging temperature is 25 °C; the drying temperature is 60 °C, and the drying time is 36 h; the calcination temperature is 300 °C, and the calcination time is 1 h;

[0103] (5) Put the precursor obtained in step (4) into a crucible and raise the temperature to 1500 °C at a heating rate of 8 °C / min, hold for 2 h for boron-carbon thermal reduction reaction, and the atmosphere is nitrogen with a flow rate of 100 mL / min to obtain a ternary high-temperature ceramic material; among them, the purity of nitrogen is 99.999%.

[0104] Example 3

[0105] The ternary high-temperature ceramic material has a chemical composition by mass percentage of: 54.6% TiB₂, 41.8% TiN, and 3.6% SiC;

[0106] The TiB₂ is hexagonal flake-shaped, the side length of the hexagonal flake is 1 - 2 μm, and the thickness of the hexagonal flake is 0.1 - 0.3 μm.

[0107] The TiN is hexagonal flake-shaped, the side length of the hexagonal flake is 0.5 - 2 μm, and the thickness of the hexagonal flake is 0.1 - 0.2 μm.

[0108] The SiC is spherical particles, and the diameter of the spherical particles is 0.1 - 0.5 μm;

[0109] The preparation method of the ternary high-temperature ceramic material is the following steps:

[0110] (1) Dissolve 39.1708 g of tetrabutyl titanate and 10.4165 g of tetraethyl orthosilicate in 400 mL of ethanol containing 9.45 mL of 2 mol / L concentrated hydrochloric acid, 250 mL of water, and 2 g of polyethylene glycol, and heat in a water bath at 60 °C to obtain a first mixed solution;

[0111] (2) Dissolve 21.9478 g of sodium tetraborate and 20.6949 g of sucrose in water at 80 °C to obtain a second mixed solution; among them, the mass ratio of tetrabutyl titanate:tetraethyl orthosilicate:sodium tetraborate:sucrose is 43%:11%:24%:22%;

[0112] (3) Drop the second mixed solution obtained in step (2) into the first mixed solution, and carry out a sol-gel reaction for 1 h under the condition of magnetic stirring at 60 °C to obtain a sol;

[0113] (4) The sol obtained in step (3) is successively aged, dried, and calcined, and then using a polytetrafluoroethylene ball mill pot and agate balls as ball milling media, ball mill on a planetary ball mill at a rotation speed of 400 r / min for 5 h to obtain a precursor; among them, the aging time is 12 h, the aging temperature is 25 °C; the drying temperature is 80 °C, and the drying time is 48 h; the calcination temperature is 300 °C, and the calcination time is 1 h;

[0114] (5) Put the precursor obtained in step (4) into a crucible and raise the temperature to 1500 °C at a heating rate of 8 °C / min. First, keep it at a constant temperature for 2 h under the condition of argon with a flow rate of 100 mL / min, then cool it down to 300 °C with the furnace and keep it at a constant temperature for 6 h under the condition of nitrogen with a flow rate of 100 mL / min to carry out the boron-carbon thermal reduction reaction to obtain a ternary high-temperature ceramic material; among them, the purities of nitrogen and argon are both 99.999%.

[0115] Figure 1 XRD patterns of the ternary high-temperature ceramic materials prepared in Examples 1-3. From Figure 1 It can be seen that the TiB2-TiN-SiC ternary high-temperature ceramic material was successfully synthesized in the present invention.

[0116] Figure 2 SEM image of the ternary high-temperature ceramic material prepared in Example 1. From Figure 2 It can be seen that the shapes of the ternary high-temperature ceramic materials are flakes and particles, and the rich interfaces and interlocking structures can improve the microwave absorption performance.

[0117] Figure 3 XPS image of the ternary high-temperature ceramic material prepared in Example 1. From Figure 3 It can be seen that the TiB2-TiN-SiC ternary high-temperature ceramic material was successfully synthesized in the present invention.

[0118] Dissolve paraffin in 1 mL of cyclohexane, then ultrasonically dissolve it at 60 °C. After adding the ternary high-temperature ceramic materials prepared in Examples 1-3 (the mass ratio of the ternary high-temperature ceramic material to paraffin is 50 wt%:50 wt%), raise the temperature to 80 °C until the cyclohexane completely volatilizes. Put the obtained solid into a mold and press it into a 2-mm-thick annular sample for microwave absorption testing. The results are as Figures 4 to 6 shown.

[0119] Figure 4 Microwave absorption image of the ternary high-temperature ceramic material prepared in Example 1; Figure 5 Microwave absorption image of the ternary high-temperature ceramic material prepared in Example 2; Figure 6 Microwave absorption image of the ternary high-temperature ceramic material prepared in Example 3.

[0120] From Figures 4 to 6 It can be seen the reflection loss of electromagnetic waves corresponding to different thicknesses, indicating the loss ability of the ternary high-temperature ceramic material to electromagnetic waves at a fixed frequency, and it has excellent microwave absorption performance.

[0121] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A ternary high-temperature ceramic microwave absorption material, the chemical composition of which, by mass percentage, includes: TiB2 43 - 60%, TiN 36 - 52%, and SiC 1 - 15%; The TiN is hexagonal flake-shaped, the side length of the hexagonal flake is 0.5 - 2 μm, and the thickness of the hexagonal flake is 0.1 - 0.2 μm; The preparation method of the ternary high-temperature ceramic microwave absorption material comprises the following steps: (1) Mix tetrabutyl titanate, tetraethyl orthosilicate, hydrochloric acid, water, an emulsifier, and ethanol to obtain a first mixed solution; (2) Mix sodium tetraborate, sucrose, and water to obtain a second mixed solution; (3) Mix the first mixed solution obtained in step (1) and the second mixed solution obtained in step (2), and carry out a sol-gel reaction to obtain a sol; (4) Subject the sol obtained in step (3) to aging, drying, and calcination in sequence to obtain a precursor; (5) Carry out a boron-carbon thermal reduction reaction on the precursor obtained in step (4) in a nitrogen atmosphere or in an argon and nitrogen atmospheres in sequence to obtain the ternary high-temperature ceramic microwave absorption material; There is no sequence priority between step (1) and step (2).

2. The ternary high-temperature ceramic microwave absorption material according to claim 1, wherein The chemical composition by mass percentage includes: TiB2 44.4 - 54.6%, TiN 41.5 - 50.8%, and SiC 3.6 - 4.8%.

3. The ternary high-temperature ceramic microwave absorption material according to claim 2, wherein The chemical composition by mass percentage includes: TiB2 54.3%, TiN 41.5%, and SiC 4.2%.

4. The ternary high-temperature ceramic microwave absorption material according to any one of claims 1 to 3, wherein The TiB2 is hexagonal flake-shaped, the side length of the hexagonal flake is 1 - 2 μm, and the thickness of the hexagonal flake is 0.1 - 0.3 μm.

5. The ternary high-temperature ceramic microwave absorption material according to any one of claims 1 to 3, wherein The SiC is spherical particles, and the diameter of the spherical particles is 0.1 - 0.5 μm.

6. A method for preparing the ternary high-temperature ceramic microwave absorption material according to any one of claims 1 to 5, comprising the following steps: (1) Mix tetrabutyl titanate, tetraethyl orthosilicate, hydrochloric acid, water, an emulsifier, and ethanol to obtain a first mixed solution; (2) Mix sodium tetraborate, sucrose, and water to obtain a second mixed solution; (3) Mix the first mixed solution obtained in step (1) and the second mixed solution obtained in step (2), and carry out a sol-gel reaction to obtain a sol; (4) Subject the sol obtained in step (3) to aging, drying, and calcination in sequence to obtain a precursor; (5) Carry out a boron-carbon thermal reduction reaction on the precursor obtained in step (4) in a nitrogen atmosphere or in an argon and nitrogen atmospheres in sequence to obtain the ternary high-temperature ceramic microwave absorption material; There is no sequence priority between step (1) and step (2).

7. The preparation method according to claim 6, wherein In step (4), the calcination temperature is 200 - 400 °C, and the calcination time is 0.5 - 2 h.

8. The preparation method according to claim 6, wherein In step (5), the temperature of the boron-carbon thermal reduction reaction is 1000 - 1500 °C, and the time of the boron-carbon thermal reduction reaction is 0.5 - 2.5 h.

9. Application of the ternary high-temperature ceramic microwave absorption material according to any one of claims 1 to 5 or the ternary high-temperature ceramic microwave absorption material prepared by the preparation method according to any one of claims 6 to 8 in aerospace devices.

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