Carbide solid solution powder containing four non-metallic elements and preparation method thereof

Abstract

The invention relates to carbide solid solution powder containing four non-metallic elements and a preparation method of the carbide solid solution powder, and belongs to the technical field of carbide ceramics. The preparation method comprises the following steps: ball-milling and mixing two kinds of metal powder and C powder, carrying out pressureless plasma sintering, and then crushing the powder to obtain carbide powder; mixing the carbide powder with g-C3N4 powder, and carrying out primary fixed-temperature heat preservation to obtain N-containing carbide powder; mixing the N-containing carbide powder with B2O3 and phenolic resin, and preserving heat at a fixed temperature for the second time to obtain carbide solid solution powder containing four non-metallic elements. The carbide powder containing N, B and O, provided by the invention, is a single-phase solid solution, has a face-centered cubic structure, is high in purity, loose in structure and easy to break, and is beneficial to later processing and application.

Description

Technical Field

[0001] The invention belongs to the technical field of carbide ceramics, and in particular relates to a carbide solid solution powder containing four non-metallic elements and a preparation method thereof. Background Art

[0002] Ultra-high temperature ceramics have high melting point, high stability and high temperature strength. They are used in components such as nose cones and wing fronts of hypersonic aircraft. They are important candidate materials for ultra-high temperature thermal protection systems. At the same time, ultra-high temperature ceramics can also meet the needs of harsh service environments such as extreme high temperatures and strong corrosive media in petrochemical downhole drill bits. Commonly used ultra-high temperature ceramics include binary ceramics such as borides, nitrides and carbides of elements such as Zr, Hf and Ti. However, the oxidation resistance and ablation resistance of binary ultra-high temperature ceramic materials have certain limitations, which affect their potential applications. For example, ZrC will be oxidized into a loose and porous zirconium oxide layer below 2500℃, which has poor oxygen isolation ability, is not resistant to heat flow erosion, and has poor high temperature oxidation resistance; when HfB2 is above 2500℃, the ceramic material will have a significant decrease in ablation resistance due to the rapid volatilization of boron oxide.

[0003] At present, in order to improve the high-temperature oxidation resistance of carbides, more attention is paid to the influence of metal components on the high-temperature oxidation resistance of carbides. High-entropy ceramics (usually refers to solid solutions formed by five or more ceramic components) have become one of the research hotspots in recent years due to their excellent performance, while there are certain limitations on the influence of non-metallic components. Common carbide ceramics are single non-metallic components containing only carbon, while carbide ceramics containing two, three or more non-metallic components and their research are less. It is reported that carbide ceramics containing two non-metallic components, one of which is a carbide solid solution containing N and C, such as (Hf 0.2 Zr 0.2 Ta 0.2 Nb 0.2 Ti 0.2) (C 0.8 N 0.2 ), Peng et al.’s research results show that N doping makes carbide ceramics form stronger chemical bonds, making them have higher ablation resistance (Peng Z, et al. Corrosion Science, 2021, 184: 109359). The second is a carbide solid solution containing B and C, such as (Zr 0.8 Ti 0.2 )(C 0.74 B 0.26)(Zeng Y, et al. Nature Communications, 2017, 8: 15836), this boron carbide ceramic exhibits better antioxidant and ablation resistance than conventional ultra-high temperature ceramics in an oxidizing environment of 3000°C. Therefore, the introduction of non-metallic components is beneficial to improving the antioxidant and ablation resistance of carbides. For carbides containing three non-metallic components, Guan et al. (GUAN J, et al. Journal of the American Ceramic Society, 2022, 105 (10): 6417-6426) mixed a variety of metal powders and amorphous BCN powders by high-energy ball milling, and hot-pressed and sintered them at 1900°C to obtain composite ceramics. The obtained ceramics consist of BN (C) phase, (Ta 0.2 Nb 0.2 Zr 0.2 Hf 0.2 Ti 0.2 )(B,C,N) phase and oxide phase. This report only found carbide phase containing B and N in the composite ceramic (i.e. (Ta 0.2 Nb 0.2 Zr 0.2 Hf 0.2 Ti 0.2 )(B, C, N)), but no method for preparing solid solution powders of carbides containing B and N is reported. In addition, there is no report on the preparation method of carbides containing four non-metallic components (B, N, O and C). Summary of the invention

[0004] In view of the above problems, the present invention provides a carbide solid solution powder containing four non-metallic elements and a preparation method thereof. By dissolving N, B and O atoms into carbides, a single-phase novel carbide solid solution containing N, B and O can be obtained. The carbide has a face-centered cubic structure, while containing a certain amount of N, B and O elements in the crystal.

[0005] The first object of the present invention is to provide a method for preparing a carbide solid solution powder containing four non-metallic elements, the preparation method comprising:

[0006] The two metal powders are mixed with C powder by ball milling, and then the powders are crushed to obtain carbide powder after pressureless plasma sintering;

[0007] The carbide powder is mixed with the g-C3N4 powder and then kept at a fixed temperature to obtain the N-containing carbide powder;

[0008] The N-containing carbide powder is mixed with B2O3 and phenolic resin and then kept at a fixed temperature for a second time to obtain a carbide solid solution powder containing four non-metallic elements.

[0009] In the embodiment of the present invention, the pressureless spark plasma sintering conditions are: the vacuum degree in the sintering furnace is less than 5 Pa, the sintering temperature is 1300-1800° C., and the holding time is 15-60 min.

[0010] In an embodiment of the present invention, the added amount of g-C3N4 is 0 to 5.0 wt% of the carbide powder, excluding zero.

[0011] In the embodiment of the present invention, the added amount of the phenolic resin is 0-5.0wt% of the carbide powder, excluding zero.

[0012] In the embodiment of the present invention, the added amount of B2O3 is 0-5.0wt% of the carbide powder, excluding zero.

[0013] In an embodiment of the present invention, the carbide powder and the g-C3N4 powder are mixed by solution mixing; the solvent selected for the solution mixing is deionized water or ethanol.

[0014] In the embodiment of the present invention, the N-containing carbide powder is mixed with B2O3 and phenolic resin by solution mixing; the solvent selected for the solution mixing is deionized water or ethanol.

[0015] In the embodiment of the present invention, the conditions for the fixed temperature insulation are temperature of 1500-1800° C., insulation for 15-60 min, heating rate of 50-150° C. / min, and vacuum degree less than 5 Pa.

[0016] In the embodiment of the present invention, the conditions for the secondary fixed temperature insulation are a temperature of 1500-1800° C., insulation for 15-60 min, a heating rate of 50-150° C. / min, and a vacuum degree of less than 5 Pa.

[0017] The second object of the present invention is to provide a carbide solid solution powder containing four non-metallic elements, wherein the molecular formula of the carbide solid solution powder containing four non-metallic elements is X a Y b C y N z B w O m , wherein X and Y are two elements among Zr, Ti and Hf, 0.6≤y<1.0, 0<z≤0.2, 0<w≤0.2, 0<m≤0.2, y+z+w+m≤1, a+b=1.

[0018] In an embodiment of the present invention, the carbide solid solution powder containing four non-metallic elements is prepared by the following steps:

[0019] The two metal powders are mixed with C powder by ball milling, and then the powders are crushed to obtain carbide powder after pressureless plasma sintering;

[0020] The carbide powder is mixed with the g-C3N4 powder and then kept at a fixed temperature to obtain the N-containing carbide powder;

[0021] The N-containing carbide powder is mixed with B2O3 and phenolic resin and then kept at a fixed temperature for a second time to obtain a carbide solid solution powder containing four non-metallic elements.

[0022] Beneficial effects of the present invention:

[0023] The present invention provides a novel carbide solid solution powder material containing four non-metallic elements, which is a carbide powder containing N, B, and O as a single phase solid solution, has a face-centered cubic structure, high purity, loose structure, and is easy to break, which is conducive to later processing and application;

[0024] The present invention adopts two transition metal elements with similar particle sizes and C powder to mix by ball milling, and prepares carbide solid solution powder with carbon vacancy defects after pressureless plasma sintering. On this basis, g-C3N4 is added as a nitrogen source to allow N atoms to fill the designed carbon vacancies without changing the crystal structure of the carbide. At the same time, B2O3 is selected as a boron source, and B2O3 is melt-infiltrated into the carbide, and its B and O atoms further fill the carbon vacancies. In order to eliminate the influence of excess O, phenolic resin is added while B2O3 is melt-infiltrated to react with excess O, eliminate the second phase, and finally form a single phase carbide powder containing N, B and O;

[0025] The method for preparing the N, B, O carbide powder provided by the present invention has a short preparation time, is easy to control the reaction process, has no impurities introduced during the process, is conducive to optimizing the content of each component, and obtains a high-purity single-phase solid solution of N, B and O carbides;

[0026] The carbide solid solution containing N, B and O of the present invention has the ultra-high melting point temperature resistance of carbides and nitrides and the oxidation resistance of oxides and borides, has strong oxidation resistance and ablation resistance in a wide temperature range, and has important potential applications in thermal protection systems.

[0027] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1 A flow chart showing a method for preparing a carbide solid solution powder containing four non-metallic elements according to an embodiment of the present invention is shown;

[0030] Figure 2 The XRD diagram of the carbide solid solution powder containing four non-metallic elements in Example 1 of the present invention is shown;

[0031] Figure 3 The scanning electron microscope image of the carbide solid solution powder containing four non-metallic elements in Example 1 of the present invention is shown;

[0032] Figure 4 Shows Figure 3 The element distribution scan in the dashed box;

[0033] Figure 5 The XRD diagram of the carbide solid solution powder containing four non-metallic elements in Example 2 of the present invention is shown;

[0034] Figure 6 The XRD diagram of the carbide solid solution powder containing four non-metallic elements in Comparative Example 1 of the present invention is shown. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] like Figure 1 As shown, a method for preparing a carbide solid solution powder containing four non-metallic elements according to an embodiment of the present invention comprises:

[0037] Step 1: The two metal powders are mixed with C powder by ball milling, and then the powders are crushed to obtain carbide powder after pressureless plasma sintering;

[0038] Step 2, mixing carbide powder and g-C3N4 powder and then heat-keeping at a fixed temperature to obtain N-containing carbide powder;

[0039] Step 3: Mix the N-containing carbide powder with B2O3 and phenolic resin and then keep them at a fixed temperature for a second time to obtain a carbide solid solution powder containing four non-metallic elements.

[0040] In step 1, the ball milling speed is 150-300 rpm, the time is 1-5 hours, the ball milling medium is ethanol and / or water, and the ball-to-material ratio is 6-10:1.

[0041] In step 1, the pressureless discharge plasma sintering conditions are: the vacuum degree in the sintering furnace is less than 5 Pa, the temperature is 1300-1800° C., the insulation time is 15-60 min, and the heating rate is 50-150° C. / min.

[0042] In step one, the crushing is followed by ball milling into powder, the rotation speed is 150-300 rpm, the ball milling time is 0.5-2 h, the ball milling medium is ethanol and / or water, and the ball-to-material ratio is 6-10:1; wherein the specific value of the rotation speed is one of 150 rpm, 160 rpm, 170 rpm, 180 rpm, 190 rpm, 200 rpm, 210 rpm, 220 rpm, 230 rpm, 240 rpm, 250 rpm, 260 rpm, 270 rpm, 280 rpm, 290 rpm, and 300 rpm, and the specific value of the ball-to-material ratio is one of 6:1, 7:1, 8:1, 9:1, and 10:1.

[0043] In step 2, the added amount of g-C3N4 is 0 to 5.0 wt% of the carbide powder, excluding zero.

[0044] In step 2, the carbide powder and the g-C3N4 powder are mixed by solution mixing, and the solvent selected for the solution mixing is deionized water or ethanol.

[0045] In step 3, the added amount of B2O3 is 0-5.0wt% of the carbide powder, excluding zero.

[0046] In step three, the amount of phenolic resin added is 0-5.0wt% of the carbide powder, excluding zero.

[0047] In step 2, the N-containing carbide powder is mixed with B2O3 and phenolic resin by solution mixing, and the solvent selected for the solution mixing is deionized water or ethanol.

[0048] In step three, the conditions for the fixed temperature insulation are a temperature of 1500-1800°C, a insulation time of 15-60min, a heating rate of 50-150°C / min, and a vacuum degree of less than 5Pa. The specific temperature value is one of 1500°C, 1550°C, 1600°C, 1650°C, 1700°C, 1750°C, and 1800°C. The specific insulation time value is one of 15min, 20min, 25min, 30min, 35min, 40min, 45min, 50min, 55min, and 60min; the heating rate is one of 50°C / min, 60°C / min, 70°C / min, 80°C / min, 90°C / min, 100°C / min, 110°C / min, 120°C / min, 130°C / min, 140°C / min, and 150°C / min.

[0049] In step three, the conditions for the secondary fixed temperature insulation are a temperature of 1500-1800°C, insulation for 15-60 min, a heating rate of 50-150°C / min, and a vacuum degree of less than 5 Pa; the specific temperature value is one of 1500°C, 1550°C, 1600°C, 1650°C, 1700°C, 1750°C, and 1800°C, and the specific insulation time is one of 15min, 20min, 25min, 30min, 35min, 40min, 45min, 50min, 55min, and 60min; the heating rate is one of 50°C / min, 60°C / min, 70°C / min, 80°C / min, 90°C / min, 100°C / min, 110°C / min, 120°C / min, 130°C / min, 140°C / min, and 150°C / min.

[0050] Example 1

[0051] Preparation of carbide solid solution powder containing four non-metallic elements:

[0052] Step 1, the two metal powders and C powder are ball-milled on a planetary ball mill for 2 hours and then taken out (the particle size of the two metal powders is -300 mesh, the C powder is -4000 mesh, the purity is ≥99%, the ball milling medium is ethanol, the rotation speed is 150rpm, and the ball-to-material ratio is 6:1), dried at 40°C, sieved to obtain a mixed powder, and the mixed powder is placed in a pressureless discharge plasma sintering graphite mold for pressureless plasma sintering. During sintering, the vacuum degree in the furnace is less than 5Pa, and the temperature is increased to 1600°C at a heating rate of 100°C / min, and kept warm for 30min, then cooled to room temperature, taken out and crushed, ball-milled into powder in a ball mill, the ball milling time is 0.5h, the ball milling medium is ethanol, the rotation speed is 200rpm, the ball-to-material ratio is 6:1, and dried at 40°C to obtain a carbide powder, wherein the two metal powders are Zr powder and Ti powder, and the molar ratio of Zr powder, Ti powder and C powder is 0.8:0.2:0.65,

[0053] Step 2: Add carbide powder and g-C3N4 powder into ionized water, stir and mix for 24 hours, take out and dry at 40°C after mixing to obtain a mixture of g-C3N4 and carbide powder, then place the mixture in a graphite can and perform a fixed temperature insulation in a vacuum sintering furnace, the vacuum degree in the furnace is less than 5Pa during the fixed temperature insulation, heat up to 1600°C at a heating rate of 50°C / min, and keep warm for 30 minutes, then cool to room temperature and take out to obtain N-containing carbide powder, wherein the molar ratio of N in g-C3N4 powder to C in carbide powder is 0.1:0.65;

[0054] Step 3: Add ethanol to N-containing carbide powder, B2O3 and phenolic resin, and stir and mix for 24 hours. After mixing, take out and dry at 40°C to obtain a mixture of B2O3, N-containing carbide powder and phenolic resin. Place the mixture in a graphite can and then perform secondary fixed temperature insulation in a vacuum sintering furnace. During the secondary fixed temperature insulation, the vacuum degree in the furnace is less than 5Pa. The temperature is increased to 1700°C at a heating rate of 100°C / min and kept warm for 30 minutes. Then, it is cooled to room temperature and taken out to obtain a carbide solid solution powder containing N, B and O (i.e., a carbide solid solution powder containing four non-metallic elements), wherein the molar ratio of B in B2O3 to C in the N-containing carbide powder is 0.1:0.65, and the added mass of phenolic resin is 1 / 3 of the mass of B2O3 powder.

[0055] The obtained carbide powder containing N, B and O was subjected to XRD test, and the test results are shown in the figure Figure 2 As shown, from Figure 2 It can be seen that the obtained carbide powder containing N, B and O has a face-centered cubic structure of a single phase.

[0056] The surface morphology of the obtained carbide powder containing N, B and O was observed by scanning electron microscopy. The obtained morphology is shown in Figure 3 As shown, from Figure 3 It can be seen that the powder particle size is ~10μm, and Figure 3 The elements contained in the powder in the dotted box area are scanned and analyzed as shown in the figure below. Figure 4 As shown, from Figure 4 It can be seen that the six elements Zr, Ti, C, N, B and O are evenly distributed among each other.

[0057] The obtained carbide powder containing N, B and O was then tested by ICP-OES element content test, and the atomic ratio of Zr to Ti was 0.80:0.20, and the atomic ratio of C, N, B and O was 0.69:0.10:0.10:0.11, forming (Zr 0.80 Ti 0.20 )(C 0.69 N 0.10 B 0.10 O 0.11 ) solid solution.

[0058] Example 2

[0059] Preparation of carbide solid solution powder containing four non-metallic elements:

[0060] Step 1: Ball mill the two metal powders and C powder in a planetary ball mill for 2 hours and then take them out (the particle size of the two metal powders is -300 mesh, the C powder is -4000 mesh, the purity is ≥99%, the ball milling medium is ethanol, the rotation speed is 200rpm, and the ball-to-material ratio is 6:1), dry at 40°C, sieve to obtain a mixed powder, place the mixed powder in a pressureless discharge plasma sintering graphite mold for pressureless plasma sintering, and the vacuum degree in the furnace is less than 5Pa during sintering. The temperature was raised to 1600°C at a heating rate of 100°C / min and kept at that temperature for 30 minutes, then cooled to room temperature, taken out and crushed, and ball-milled into powder in a ball mill. The ball milling time was 0.5h, the ball milling medium was ethanol, the speed was 200rpm, the ball-to-material ratio was 6:1, and the carbide powder was obtained after drying at 40°C, wherein the two metal powders were Zr powder and Hf powder, and the molar ratio of Zr powder, Hf powder and C powder was 0.62:0.38:0.7;

[0061] Step 2, add carbide powder and g-C3N4 powder into ionized water, stir and mix for 24 hours, take out and dry at 40°C after mixing to obtain a mixture of g-C3N4 and carbide powder, then place the mixture in a graphite can and then perform a fixed temperature insulation in a vacuum sintering furnace, the vacuum degree in the furnace is less than 5Pa during the fixed temperature insulation, heat up to 1600°C at a heating rate of 50°C / min, and keep warm for 30 minutes, then cool to room temperature and take out to obtain N-containing carbide powder, wherein the molar ratio of N in g-C3N4 powder to C in carbide powder is 0.1:0.7;

[0062] Step 3: Add N-containing carbide powder, B2O3 and phenolic resin to ethanol and stir and mix for 24 hours. After mixing, take out and dry at 40°C to obtain a mixture of B2O3, N-containing carbide powder and phenolic resin. Place the mixture in a graphite can and then perform secondary fixed temperature insulation in a vacuum sintering furnace. During the secondary fixed temperature insulation, the vacuum degree in the furnace is less than 5Pa. The temperature is increased to 1700°C at a heating rate of 100°C / min and kept warm for 30 minutes. Then, it is cooled to room temperature and taken out to obtain a solid solution powder of carbides containing N, B and O (i.e., a solid solution powder of carbides containing four non-metallic elements), wherein the molar ratio of B in B2O3 to C in the N-containing carbide powder is 0.1:0.7, and the added mass of phenolic resin is 1 / 3 of the mass of B2O3 powder.

[0063] The obtained carbide powder containing N, B and O was subjected to XRD test, and the test results are shown in the figure Figure 5 As shown, from Figure 5 It can be seen that the obtained carbide powder containing N, B and O has a face-centered cubic structure of a single phase, and the atomic ratio of Zr and Hf is 0.62:0.38, and the atomic ratio of C, N, B and O is 0.75:0.10:0.08:0.07 according to ICP-OES element content analysis, forming (Zr 0.62 Hf 0.38 )(C 0.75 N 0.10 B 0.08 O 0.07 ) solid solution.

[0064] Comparative Example 1

[0065] Preparation of solid solution powder:

[0066] Step 1, the two metal powders and C powder are ball-milled on a planetary ball mill for 2 hours and then taken out (the particle size of the two metal powders is -300 mesh, the C powder is -4000 mesh, the purity is ≥99%, the ball milling medium is ethanol, the rotation speed is 150rpm, and the ball-to-material ratio is 6:1), dried at 40°C, sieved to obtain a mixed powder, and the mixed powder is placed in a pressureless discharge plasma sintering graphite mold for pressureless plasma sintering. During sintering, the vacuum degree in the furnace is less than 5Pa, and the temperature is increased to 1600°C at a heating rate of 100°C / min, and kept warm for 30min, then cooled to room temperature, taken out and broken, ball-milled into powder in a ball mill, the ball milling time is 0.5h, the ball milling medium is ethanol, the rotation speed is 200rpm, the ball-to-material ratio is 6:1, and dried at 40°C to obtain a carbide powder, wherein the two metal powders are Zr powder and Ti powder, and the molar ratio of Zr powder, Ti powder and C powder is 0.8:0.2:0.65;

[0067] Step 2: Add carbide powder, g-C3N4 powder, B2O3 powder and phenolic resin to ethanol and stir and mix for 24 hours. After mixing, take out and dry at 40°C to obtain a mixture of B2O3, N-containing carbide powder and phenolic resin. Place the mixture in a graphite can and then perform secondary fixed temperature insulation in a vacuum sintering furnace. During the secondary fixed temperature insulation, the vacuum degree in the furnace is less than 5 Pa. The temperature is increased to 1700°C at a heating rate of 100°C / min and kept warm for 30 minutes. Then, it is cooled to room temperature and taken out to obtain a powder, wherein the molar ratio of N in g-C3N4 powder to C in carbide powder is 0.1:0.65, the molar ratio of B in B2O3 to C in N-containing carbide powder is 0.1:0.7, and the added mass of phenolic resin is 1 / 3 of the mass of B2O3 powder.

[0068] The obtained powder was subjected to XRD test, and the test results are shown in the figure Figure 6 As shown, from Figure 6 It can be seen that the prepared powder has diffraction peaks of Zr-Ti-CNBO solid solution phase, t-(Zr,Ti)O2, m-ZrO2 and TiB2, indicating that the powder is a mixture of these four substances, among which the Zr-Hf-Ti-CBN solid solution shows the characteristic peak of ZrC, indicating that the nitrogen source, boron source and carbon source are added simultaneously, and the prepared powder cannot form a single phase containing N, B and O carbide solid solution powder.

[0069] Comparative Example 2

[0070] Preparation of solid solution powder:

[0071] The same as Example 1, except that step 2 is omitted.

[0072] (1) Zr powder, Ti powder and C powder were mixed in a molar ratio of 0.8:0.2:0.65, and ball milled for 2 h in a planetary ball mill, wherein the ball milling medium was ethanol, the rotation speed was 200 rpm, and the ball-to-material ratio was 6:1. After ball milling, the mixture was taken out, dried at 40° C., and sieved to obtain a mixed powder;

[0073] (2) placing the mixed powder in a pressureless discharge plasma sintering graphite mold for pressureless discharge plasma sintering, with a vacuum degree of less than 5 Pa in the furnace, heating the mixture to 1600° C. at a heating rate of 100° C. / min and keeping the temperature for 30 min, then cooling the mixture to room temperature, taking it out and crushing it, and grinding it into powder in a ball mill, wherein the ball milling medium is ethanol, the rotation speed is 200 rpm, the ball-to-material ratio is 6:1, the ball milling time is 0.5 h, taking it out after ball milling, and drying it at 40° C. to obtain carbide powder;

[0074] (3) Based on the B element in the B2O3 powder and the C element in the carbide powder, the B2O3 powder and the above-mentioned carbide powder are mixed in ethanol at a molar ratio of 0.1:0.8, and 5wt% phenolic resin based on the total mass of the powder is added. After 24 hours, the powder is taken out and dried at 40°C; then, it is placed in a graphite pot and pressurelessly sintered in a vacuum sintering furnace with a vacuum degree of less than 5Pa. The temperature is raised to 1600°C at a heating rate of 50°C / min, and the temperature is kept for 30 minutes. Then, it is cooled to room temperature and taken out to obtain boron carbide powder.

[0075] According to ICP-OES element content analysis, the atomic ratio of Zr to Ti is 0.80:0.20, the atomic ratio of C to B is 0.70:0.09, and the molecular formula of the boron carbide powder is (Zr 0.80 Ti 0.20 )(C 0.70 B 0.09 ).

[0076] The products prepared in Example 1 and Comparative Example 2 were tested for their antioxidant properties, and the test results are shown in Table 1. The products prepared in Example 1 and Comparative Example 2 were tested for their antioxidant properties by TG-DSC in an air atmosphere, with a heating rate of 10°C / min, a product particle size of 10 to 100 μm, and an air atmosphere, and the initial oxidation temperature was read from the DSC heating curve. The higher the initial oxidation temperature, the better the antioxidant property of the product.

[0077] Table 1

[0078] Initial oxidation temperature / ℃ Example 1 685 Comparative Example 2 660

[0079] It can be seen from the data in Table 1 that the anti-oxidation performance of the carbide solid solution containing four non-metallic elements obtained in Example 1 is better than the anti-oxidation performance of the solid solution obtained in Comparative Example 2.

[0080] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent substitutions for some of the technical features therein; and these modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a solid solution powder of carbides containing four non-metallic elements, characterized in that: include: The two metal powders are mixed with C powder by ball milling, and then the powders are crushed to obtain carbide powder after pressureless plasma sintering; The carbide powder is mixed with the g-C3N4 powder and then kept at a fixed temperature to obtain the N-containing carbide powder; The N-containing carbide powder is mixed with B2O3 and phenolic resin and then kept at a fixed temperature for a second time to obtain a carbide solid solution powder containing four non-metallic elements.

2. The method for preparing a solid solution powder of carbides containing four non-metallic elements according to claim 1, characterized in that: The pressureless discharge plasma sintering conditions are as follows: the vacuum degree in the sintering furnace is less than 5 Pa, the sintering temperature is 1300-1800° C., and the heat preservation time is 15-60 minutes.

3. The method for preparing a solid solution powder of carbides containing four non-metallic elements according to claim 1, characterized in that: The added amount of g-C3N4 is 0 to 5.0 wt% of the carbide powder, excluding zero.

4. The method for preparing a solid solution powder of carbides containing four non-metallic elements according to claim 1, characterized in that: The added amount of the phenolic resin is 0-5.0wt% of the carbide powder, excluding zero.

5. The method for preparing a solid solution powder of carbides containing four non-metallic elements according to claim 1, characterized in that: The added amount of B2O3 is 0-5.0wt% of the carbide powder, excluding zero.

6. The method for preparing a solid solution powder of carbides containing four non-metallic elements according to claim 1, characterized in that: When the carbide powder and the g-C3N4 powder are mixed, solution mixing is adopted; the solvent selected for the solution mixing is deionized water or ethanol.

7. The method for preparing a solid solution powder of carbides containing four non-metallic elements according to claim 1, characterized in that: When the N-containing carbide powder is mixed with B2O3 and phenolic resin, solution mixing is adopted; the solvent selected for the solution mixing is deionized water or ethanol.

8. The method for preparing a solid solution powder of carbides containing four non-metallic elements according to claim 1, characterized in that: The conditions for the fixed temperature insulation are as follows: temperature of 1500-1800° C., insulation of 15-60 min, heating rate of 50-150° C. / min, and vacuum degree of less than 5 Pa.

9. The method for preparing a solid solution powder of carbides containing four non-metallic elements according to any one of claims 1 to 8, characterized in that: The conditions for the secondary fixed temperature insulation are a temperature of 1500-1800° C., insulation for 15-60 min, a heating rate of 50-150° C. / min, and a vacuum degree of less than 5 Pa.

10. A solid solution powder containing four non-metallic elements, characterized in that: The molecular formula is X a Y b C y N z B w O m , wherein X and Y are two elements among Zr, Ti and Hf, 0.6≤y<1.0, 0<z≤0.2, 0<w≤0.2, 0<m≤0.2, y+z+w+m≤1, a+b=1.

11. The carbide solid solution powder containing four non-metallic elements according to claim 10 is prepared by the following steps: The two metal powders are mixed with C powder by ball milling, and then the powders are crushed to obtain carbide powder after pressureless plasma sintering; The carbide powder is mixed with the g-C3N4 powder and then kept at a fixed temperature to obtain the N-containing carbide powder; The N-containing carbide powder is mixed with B2O3 and phenolic resin and then kept at a fixed temperature for a second time to obtain a carbide solid solution powder containing four non-metallic elements.

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