A carbide high-entropy-sic composite ceramic powder and a preparation method thereof

Abstract

The present application relates to high-entropy compound preparation technical field, especially to a kind of carbide high-entropy-SiC composite ceramic powder and preparation method thereof.Carbide high-entropy-SiC composite ceramic powder, molecular formula is XC-SiC, wherein X is four or five elements in Hf, Nb, Zr, Ta, Ti equimolar ratio combination.The carbide high-entropy-SiC composite ceramic powder prepared by the present application has lower oxygen content, and has wide potential application value in the field of energy, aviation and aerospace.The preparation method provided by the present application can greatly improve the uniformity of each element on molecular scale, thereby the preparation temperature can be reduced, and the equipment required by the method is simple, a series of composite ceramic powders can be obtained, and the powder has the advantages of high purity.

Description

Technical Field

[0001] This invention relates to the field of high-entropy compound preparation technology, and in particular to a high-entropy carbide-SiC multiphase ceramic powder and its preparation method. Background Technology

[0002] High-entropy ceramics are a new type of ceramic that has emerged in recent years. They are defined as ceramics containing at least five elements, with no dominant element, and all elements comprising 5%-35% of the total content. To date, research on high-entropy ceramics mainly focuses on carbide high-entropy ceramics, boride high-entropy ceramics, and silicide high-entropy ceramics. High-entropy ceramics possess high melting points, good corrosion resistance, and excellent electrochemical properties, showing great potential for development in ultra-high temperature and energy fields.

[0003] Current research on high-entropy ceramics is still in the exploratory stage, and the preparation of high-entropy ceramics mainly focuses on the preparation of bulk materials. Most preparation methods use transition metal oxides, carbides, silicides, and borides as raw materials, and utilize hot pressing sintering, spark plasma sintering, and other methods under high temperature and high pressure to obtain dense high-entropy bulk materials. These methods can currently successfully synthesize most high-entropy ceramics. High-entropy carbide-SiC multiphase ceramics possess excellent oxidation / ablation resistance and are one of the effective ways to improve the mechanical properties and oxidation / ablation resistance of high-entropy carbide ceramics. However, obtaining multiphase ceramics with uniform composition remains a bottleneck problem. To date, the literature on the synthesis of high-entropy carbide-SiC multiphase ceramics includes: H. Wang, S. Wang, Y. Cao, W. Liu, Y. Wang, Oxidation behaviors of (Hf 0.25 Zr 0.25 Ta 0.25 Nb 0.25 )C and(Hf 0.25 Zr 0.25 Ta 0.25 Nb 0.25)C-SiC at 1300-1500℃, J.Mater.Sci.Technol.60(2020)147-155 and W.Guo, J.Hu, Y.Ye, S.Bai, Ablation behavior of (TiZrHfNbTa)Chigh-entropy ceramics with the addition of SiC secondary underan oxyacetylene flame, Ceram. Int. 48(9)(2022)12790-12799. Both of the above-mentioned papers used transition metal carbides and SiC as raw materials, and obtained dense bulk materials through spark plasma sintering. However, this method is not suitable for synthesizing powder materials. (Li Lu, Tonghui Wen, Wei Li, Qingbo Wen, Zhaoju Yu, Shasha Tao, Jincan Yang, Yalei Wang, Xingang Luan, Xiang Xiong, Ralf Riedel, Single-source-precursor synthesis of dense monolithic SiC / (Ti 0.25 Zr 0.25 Hf 0.25 Ta 0.25 (Cceramic nanocomposite with excellent high-temperature oxidation resistance. Journal of the European Ceramic Society 44(2024) 594-609. This paper uses an amino metal salt as the transition metal source and allyl hydrogenated polycarbosilane (AHPCS) as the silicon source to obtain (Ti 0.25 Zr 0.25 Hf 0.25 Ta 0.25 C-SiC composite ceramic powder, but the reagents used in the literature require strict isolation from air. Although the yield is high, the actual operation is difficult and subject to certain limitations.

[0004] To improve yield and obtain a class of carbide high-entropy-SiC multiphase ceramic powders with a wide preparation range, this invention proposes a new preparation method. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a high-entropy carbide-SiC multiphase ceramic powder and its preparation method. The preparation method has advantages such as simple preparation equipment, low preparation temperature, ability to obtain a series of multiphase ceramic powders, and high powder purity.

[0006] This invention provides a high-entropy carbide-SiC multiphase ceramic powder with the molecular formula XC-SiC, where X is an equimolar combination of four or five elements selected from Hf, Nb, Zr, Ta, and Ti.

[0007] This invention also provides a method for preparing carbide high-entropy-SiC multiphase ceramic powder, comprising the following steps:

[0008] S1. Weigh the raw material and dissolve it in solvent A to obtain mixed solution A; the raw material is four or five of the following: Hf source, Nb source, Zr source, Ta source, and Ti source;

[0009] S2. Add silane to mixed solution A, and mix thoroughly to obtain mixed solution B;

[0010] S3. Add solvent B to the mixed solution B, stir until uniform, solidify, and grind to obtain precursor powder;

[0011] S4. The precursor powder obtained in step S3 is heat-treated under an argon protective atmosphere and then cooled to room temperature to obtain carbide high-entropy-SiC multiphase ceramic powder.

[0012] Preferably, the Hf source is HfCl4, the Nb source is NbCl5, and the Zr source is ZrCl4 or C. 12 H 28 The Ta source is one of O4Zr or ZrOCl2·8H2O, and the Ti source is TiCl4 or C. 16 H 36 O4Ti or C8H 20 One of the O4Ti types.

[0013] Preferably, the silane includes one or both of methyltrimethoxysilane or dimethyldimethoxysilane.

[0014] Preferably, the molar ratio Si / M of the silane to the total number of moles of all metal elements in the raw material is 1-5:1.

[0015] Preferably, solvent A in step S1 is a n-butanol solution; solvent B in step S3 is acetylacetone.

[0016] Preferably, the number of moles of solvent B added is equal to the total number of moles of all metal elements in the raw material.

[0017] Preferably, the curing temperature in step S3 is 80-200℃.

[0018] Preferably, the heat treatment conditions in step S4 are: temperature of 1200-1800℃, heating rate of 3℃ / min-9℃ / min, and heat treatment holding time of 0.5-2h.

[0019] Preferably, the temperature of the heat treatment is 1500-1800℃.

[0020] Beneficial effects:

[0021] The high-entropy carbide-SiC multiphase ceramic powder prepared by this invention has a low oxygen content (oxygen content < 0.9%) and excellent electrochemical performance, and has broad potential application value in energy, aviation and aerospace fields.

[0022] The preparation method provided by this invention dissolves the raw materials Hf source, Nb source, Zr source, Ta source, and Ti source in a solvent, achieving superior uniformity compared to traditional mixing methods. Simultaneously, the addition of the solvent B-acetylacetone enables the solution to form a polymer, preventing liquid segregation. The silane used is methyltrimethoxysilane or dimethyldimethoxysilane, avoiding the risk of failure upon exposure to air and enhancing the precursor's resistance to hydrolysis. This preparation method significantly improves the uniformity of each element at the molecular scale, thereby reducing the preparation temperature. Furthermore, the method requires simple equipment, can obtain a series of multiphase ceramic powders, and the powders possess high purity. Attached Figure Description

[0023] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0024] Figure 1 For (Hf) 0.25 Nb 0.25 Zr 0.25 Ta 0.25 XRD pattern of C-SiC multiphase ceramic powder;

[0025] Figure 2 For (Hf) 0.25 Ti 0.25 Zr 0.25 Ta 0.25 XRD pattern of C-SiC multiphase ceramic powder;

[0026] Figure 3 For (Hf) 0.2 Nb 0.2 Zr 0.2 Ta 0.2 Ti 0.2 XRD pattern of C-SiC multiphase ceramic powder. Detailed Implementation

[0027] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0028] It should be noted that the terminology used herein is for the purpose of describing particular implementations only and is not intended to limit the exemplary implementations according to this application. As used herein, the singular form includes the plural form unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this description, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0029] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. 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.

[0030] Example 1

[0031] A type of (Hf) 0.25 Nb 0.25 Zr 0.25 Ta 0.25 The preparation method of C-SiC multiphase ceramic powder includes the following steps:

[0032] S1. Weigh 0.01 mol HfCl4, 0.01 mol NbCl5, 0.01 mol ZrCl4, and 0.01 mol TaCl5, dissolve them in n-butanol solution to obtain mixed solution A;

[0033] S2. Weigh 0.04 mol of methyltrimethoxysilane and add it to mixed solution A. After mixing evenly, mixed solution B is obtained.

[0034] S3. Add 0.04 mol of acetylacetone solution to mixed solution B, stir evenly, solidify at 100℃, and grind to obtain precursor powder;

[0035] S4. The precursor powder obtained in step S3 is kept at 1500℃ for 2 hours under an argon atmosphere, with a heating rate of 5℃ / min. After cooling to room temperature, (Hf) is obtained. 0.25 Nb 0.25 Zr 0.25 Ta 0.25 XRD patterns of C-SiC composite ceramic powder are attached. Figure 1 .

[0036] Example 2

[0037] A type of (Hf) 0.25 Ti 0.25 Zr 0.25 Ta 0.25 The preparation method of C-SiC multiphase ceramic powder includes the following steps:

[0038] S1. Weigh out 0.015 mol HfCl4 and 0.015 mol gC 16 H 36 O4Ti, 0.015mol C 12 H 28 O4Zr and 0.015 mol TaCl5 are dissolved in n-butanol solution to obtain mixed solution A;

[0039] S2. Weigh 0.04 mol of methyltrimethoxysilane and 0.04 mol of dimethyldimethoxysilane and add them to mixed solution A. After mixing evenly, mixed solution B is obtained.

[0040] S3. Add 0.06 mol of acetylacetone solution to mixed solution B, stir evenly, solidify at 120℃, and grind to obtain precursor powder;

[0041] S4. The precursor powder obtained in step S3 is kept at 1600℃ for 1 hour under an argon atmosphere, with a heating rate of 6℃ / min. After cooling to room temperature, (Hf) is obtained. 0.25 Ti 0.25 Zr 0.25 Ta 0.25 XRD patterns of C-SiC multiphase ceramic powder are attached. Figure 2 .

[0042] Example 3

[0043] A type of (Hf) 0.25 Ti 0.25 Zr 0.25 Ta 0.25 The preparation method of C-SiC multiphase ceramic powder includes the following steps:

[0044] S1. Weigh out 0.01 mol HfCl4 and 0.01 mol C8H 20 O4Ti, 0.01 mol ZrOCl2·8H2O, and 0.01 mol TaCl5 are dissolved in n-butanol solution to obtain mixed solution A;

[0045] S2. Weigh 0.12 mol of dimethyldimethoxysilane and add it to mixed solution A. After mixing evenly, mixed solution B is obtained.

[0046] S3. Add 0.04 mol of acetylacetone solution to mixed solution B, stir evenly, solidify at 150℃, and grind to obtain precursor powder.

[0047] S4. The precursor powder obtained in step S3 is kept at 1700℃ for 0.5h under an argon atmosphere, with a heating rate of 7℃ / min. After cooling to room temperature, (Hf) is obtained. 0.25 Ti 0.25 Zr 0.25 Ta 0.25 XRD patterns of C-SiC multiphase ceramic powder are attached. Figure 2 .

[0048] Example 4

[0049] A type of (Hf) 0.2 Nb 0.2 Zr 0.2 Ta 0.2 Ti 0.2 The preparation method of C-SiC multiphase ceramic powder, and its XRD pattern are shown in the appendix. Figure 3 This includes the following steps:

[0050] S1. Weigh 0.02 mol HfCl4, 0.02 mol TiCl4, 0.02 mol ZrCl4, 0.02 mol TaCl5, and 0.02 mol NbCl5, dissolve them in n-butanol solution to obtain mixed solution A;

[0051] S2. Weigh 0.4 mol of dimethyldimethoxysilane and add it to mixed solution A. After mixing evenly, mixed solution B is obtained.

[0052] S3. Add 0.1 mol of acetylacetone solution to mixed solution B, stir until homogeneous, solidify at 180℃, and grind to obtain precursor powder.

[0053] S4. The precursor powder obtained in step S3 is kept at 1800℃ for 1 hour under an argon atmosphere, with a heating rate of 5℃ / min. After cooling to room temperature, (Hf) is obtained. 0.2 Nb 0.2 Ti0.2 Zr 0.2 Ta 0.2 XRD patterns of C-SiC composite ceramic powder are attached. Figure 3 .

[0054] Example 5

[0055] A type of (Hf) 0.2 Nb 0.2 Zr 0.2 Ta 0.2 Ti 0.2 The preparation method of C-SiC multiphase ceramic powder includes the following steps:

[0056] S1. Weigh out 0.025 mol HfCl4 and 0.025 mol C 16 H 36 O4Ti, 0.025mol C 12 H 28 O4Zr, 0.025 mol TaCl5, and 0.025 mol NbCl5 are dissolved in n-butanol solution to obtain mixed solution A;

[0057] S2. Weigh 0.4 mol of methyltrimethoxysilane and 0.225 mol of dimethyldimethoxysilane and add them to mixed solution A. After mixing evenly, mixed solution B is obtained.

[0058] S3. Add 0.125 mol of acetylacetone solution to mixed solution B, stir evenly, solidify at 200℃, and grind to obtain precursor powder;

[0059] S4. The precursor powder obtained in step S3 is kept at 1600℃ for 1.5h under an argon atmosphere, with a heating rate of 6℃ / min. After cooling to room temperature, (Hf) is obtained. 0.2 Nb 0.2 Ti 0.2 Zr 0.2 Ta 0.2 XRD patterns of C-SiC multiphase ceramic powder are attached. Figure 3 .

[0060] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-entropy carbide-SiC multiphase ceramic powder, characterized in that, The molecular formula is XC-SiC, where X is a combination of four or five elements selected from Hf, Nb, Zr, Ta, and Ti in equal molar ratios. Its preparation method includes the following steps: S1. Weigh the raw material and dissolve it in solvent A to obtain mixed solution A; the raw material is four or five of the following: Hf source, Nb source, Zr source, Ta source, and Ti source; the solvent A is a n-butanol solution; S2. Add silane to mixed solution A, mix thoroughly to obtain mixed solution B, wherein the silane includes one or both of methyltrimethoxysilane or dimethyldimethoxysilane, and the molar ratio Si / M of the silane to the total number of moles M of all metal elements in the raw material is 1-5:1; S3. Add solvent B to the mixed solution B, stir until homogeneous, solidify, and grind to obtain precursor powder; the solvent B is acetylacetone. S4. The precursor powder obtained in step S3 is heat-treated under an argon protective atmosphere and then cooled to room temperature to obtain carbide high-entropy-SiC multiphase ceramic powder; the heat treatment temperature is 1200-1800℃.

2. The carbide high-entropy-SiC multiphase ceramic powder according to claim 1, characterized in that, The Hf source is HfCl4, the Nb source is NbCl5, and the Zr source is ZrCl4 and C. 12 H 28 One of O4Zr or ZrOCl2·8H2O, wherein the Ta source is TaCl5, and the Ti source is TiCl4 or C. 16 H 36 O4Ti or C8H 20 One of the O4Ti types.

3. The carbide high-entropy-SiC multiphase ceramic powder according to claim 1, characterized in that, The number of moles of solvent B added is equal to the total number of moles of all metal elements in the raw material.

4. The carbide high-entropy-SiC multiphase ceramic powder according to claim 1, characterized in that, The curing temperature in step S3 is 80-200℃.

5. The carbide high-entropy-SiC multiphase ceramic powder according to claim 1, characterized in that, The heat treatment conditions in step S4 are as follows: temperature is 1500-1800℃, heating rate is 3℃ / min-9℃ / min, and heat treatment holding time is 0.5-2h.

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