A multiphase carbide and a preparation method and application thereof

Abstract

The application discloses a kind of multiphase carbide and preparation method and application, belong to multiphase carbide technical field, including the following steps: first, four or more than four transition metal salt containing equimolar amount of metal cation is weighed and dissolved in water and mixed uniformly to obtain transition metal salt solution, then modified mesoporous carbon microspheres are added, stirred for 10-20min, then stand for 6-8h, filter, dry, to obtain intermediate product;Second, intermediate product and deionized water are added into polytetrafluoroethylene lined autoclave, stirred uniformly to carry out hydrothermal reaction, after reaction, cool to room temperature, filter the reaction solution, filter cake is washed with distilled water and anhydrous ethanol in turn, after drying, to obtain precursor powder;Third, precursor powder is treated in vacuum condition, temperature 750-950 DEG C environment for 4-5h, to obtain multiphase carbide, the obtained product has high purity, low oxygen content and high antioxidant properties.

Description

Technical Field

[0001] This invention belongs to the field of multiphase carbide technology, specifically relating to a multiphase carbide, its preparation method, and its application. Background Technology

[0002] With the rapid development of space shuttles, reusable rockets, and supersonic spacecraft, higher requirements have been placed on the ablation and oxidation resistance of their thermal protection system materials, especially the long-term ablation and oxidation resistance at temperatures as high as 3000℃. Currently, traditional binary ultra-high temperature ceramics (ZrB2, HfB2, ZrC, HfC, TaC, HfN, etc.) are difficult to meet this requirement. Inspired by high-entropy alloys, researchers have recently attempted to introduce multiple transition metal elements to form single compounds, obtaining multi-element high-entropy carbides that are more suitable for service in high-temperature environments.

[0003] Currently, the main method for preparing high-entropy carbides is the solid-state method. For example, metal carbide powder is used as raw material, and atoms diffuse to form a single-phase solid solution through high temperature and spark plasma sintering (SPS). Alternatively, metal oxides and graphite powder are used to prepare the high-entropy carbides through carbothermic reduction reaction. Or, metal monomers and graphite powder are used to introduce carbon into the alloy structure at room temperature through ball milling. Although the raw materials for the solid-state method are readily available and the equipment is simple, the high-entropy carbides prepared still have the following problems: (1) The solid-state method requires ball milling of the raw materials to make them more uniform. In this process, oxygen or other metal impurities will inevitably be introduced, reducing the purity of the powder and thus affecting the material properties. (2) The particle size of the raw material powder is large, reaching the micron level, which is not conducive to atomic diffusion and easily causes incomplete solid solution reaction, making it impossible to prepare the current powder. (3) Due to the influence of the particle size of the raw material, the powder obtained by the solid-state method has a large particle size and uneven distribution, making it difficult to prepare uniform nanoparticles. Summary of the Invention

[0004] The purpose of this invention is to overcome at least one of the aforementioned problems in conventional technologies and to provide a multiphase carbide, its preparation method, and its application. The invention uses mesoporous carbon microspheres with high chemical activity and large specific surface area as the carbon source. Zirconium dihydrogenate is loaded onto the surface of the mesoporous carbon microspheres via an impregnation method. Then, utilizing the adsorption properties of the loaded zirconium dihydrogenate carbon microspheres and the interaction between the surface oxygen-containing groups and citric acid and trimethylolpropane, terminal carboxyl-terminated hyperbranched polyesters are introduced onto the surface of the loaded zirconium dihydrogenate carbon microspheres to obtain modified mesoporous carbon microspheres. Subsequently, using the modified mesoporous carbon microspheres as a substrate, highly active metal oxides or hydroxides are loaded onto the surface of the modified carbon microspheres via a hydrothermal co-precipitation method. After vacuum treatment, a nanoscale multiphase carbide with uniform chemical composition distribution, low oxygen content, and high antioxidant properties is obtained.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] A method for preparing a multiphase carbide includes the following steps:

[0007] Step 1: Weigh out four or more transition metal salts containing equimolar amounts of metal cations, dissolve them in water and mix them evenly to obtain a transition metal salt solution. Then add modified mesoporous carbon microspheres, stir for 10-20 minutes, let stand for 6-8 hours, filter, and dry to obtain the intermediate product.

[0008] The second step involves adding the intermediate product and deionized water into a hydrothermal reactor lined with polytetrafluoroethylene, stirring until homogeneous, and then cooling to room temperature. The reaction solution is filtered, and the filter cake is washed successively with distilled water and anhydrous ethanol. After drying, the precursor powder is obtained.

[0009] The third step is to treat the precursor powder under vacuum conditions at a temperature of 750-950℃ for 4-5 hours to obtain the multiphase carbide.

[0010] Furthermore, in the first step, the ratio of the total metal cations in the modified mesoporous carbon microspheres to the transition metal salt is 12.5-13.5 g: 1 mol, the concentration of the transition metal salt solution is 0.4 mol / L, and the transition metal salt is one or more of the chloride, oxychloride, sulfate and ammonium salt of the transition metal, and the transition metal is one of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo and W.

[0011] Furthermore, in the second step, the mass ratio of intermediate product to deionized water is 1:10-15, the hydrothermal reaction temperature is 150-200℃, and the reaction time is 6-10h.

[0012] Furthermore, the modified mesoporous carbon microspheres are obtained through the following steps:

[0013] S1. Zirconium dihydrogenate, anhydrous ethanol and N,N-dimethylformamide were added to a flask and ultrasonically dispersed for 1 h to obtain a suspension. Mesoporous carbon microspheres were added to the suspension and ultrasonically treated for 5-10 min. After filtration, the filter cake was dried at 70 °C to constant weight to obtain the loaded zirconium dihydrogenate carbon microspheres.

[0014] S2. Add citric acid, trimethylolpropane, supported zirconium dihydrogen styrene carbon microspheres, p-toluenesulfonic acid, and N,N-dimethylformamide to the flask. Stir at 100-200 r / min for 10-20 min, then heat to 125℃ and control the stirring speed at 220 r / min. The system vacuum degree is 0.08 MPa. React for 3-4 h. After the reaction is complete, filter the mixture. Wash the filter cake 3-5 times with anhydrous ethanol and dry it to obtain modified mesoporous carbon microspheres.

[0015] Furthermore, the ratio of zirconium dihydrogen phosphate, anhydrous ethanol, N,N-dimethylformamide, and mesoporous carbon microspheres in S1 is 0.5-3g: 100-160mL: 800-850mL: 5-10g.

[0016] Furthermore, the ratio of citric acid, trimethylolpropane, supported zirconium dihydrogen saturated carbon microspheres, p-toluenesulfonic acid, and N,N-dimethylformamide in S2 is 0.015 mol: 0.005 mol: 3.5-8.5 g: 0.07 g: 150-200 mL.

[0017] Furthermore, the mesoporous carbon microspheres were prepared by a method well known to those skilled in the art, specifically by a hydrothermal method using triblock copolymer F127 as a template agent and low-order phenolic resin as a carbon source.

[0018] Furthermore, a multiphase carbide is prepared by the above-described preparation method.

[0019] Furthermore, the aforementioned multiphase carbides can be used to prepare high-temperature carbide thermal barrier coatings and carbide-reinforced metal-ceramic matrix composites.

[0020] The beneficial effects of this invention are:

[0021] 1. This invention uses mesoporous carbon microspheres with high chemical activity and large specific surface area as the carbon source. Zirconium dihydrogenate is loaded onto the surface of the mesoporous carbon microspheres by impregnation. Then, utilizing the adsorption properties of the loaded zirconium dihydrogenate carbon microspheres and the interaction between the oxygen-containing groups on the surface and citric acid and trimethylolpropane, a carboxyl-terminated hyperbranched polyester is introduced onto the surface of the loaded zirconium dihydrogenate carbon microspheres to obtain modified mesoporous carbon microspheres. Then, using the modified mesoporous carbon microspheres as the substrate, highly active metal oxides or hydroxides are loaded onto the surface of the modified carbon microspheres by hydrothermal coprecipitation. After vacuum treatment, a nanoscale, chemically uniformly distributed, low oxygen content, and high antioxidant properties multiphase carbide is obtained.

[0022] 2. In this invention, zirconium dihydrogenate is loaded onto mesoporous carbon microspheres. During the treatment of precursor powder at a temperature of 750-950℃, the Zr produced by the decomposition of zirconium dihydrogenate reacts with O when heated. On the one hand, it consumes the oxygen content in the system, and on the other hand, it forms dense zirconium oxide that blocks the pores, hinders the further diffusion of the oxidizing atmosphere, and improves the oxidation resistance of the multiphase carbide.

[0023] 3. This invention introduces carboxyl-terminated hyperbranched polyester on the surface of supported zirconium dihydrogen phosphate carbon microspheres. The active carboxyl groups are used to perform complexation reactions on transition metal ions. Combined with the adsorption properties of transition metal ions by the internal cavities of the hyperbranched polymer, the mesoporous carbon microspheres are tightly bound to the transition metal ions, which helps to shorten the diffusion distance of the substances and improve the reaction rate.

[0024] 4. The multiphase carbide prepared by the present invention has a short preparation time, a simple process, no impurities are introduced during the process, small particle size, uniform distribution of metal elements, and excellent oxidation resistance. It can be used in various fields such as aerospace components, coating materials, and feature-functional ceramics. Attached Figure Description

[0025] The invention will now be further described with reference to the accompanying drawings.

[0026] Figure 1 This is the DSC spectrum of the multiphase carbide prepared in Example 1 of the present invention. Detailed Implementation

[0027] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. 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 of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0028] Example 1

[0029] Please see Figure 1 A method for preparing a multiphase carbide includes the following steps:

[0030] Step 1: Weigh out equimolar amounts of the metal salts and dissolve them in 12.5 mL of deionized water. Specifically, the metal salts are 1.6113 g ZrOCl2·8H2O, 1.2001 g Ti(SO4)2, 1.358 g NbCl5, and 0.5849 g NH4VO3. After mixing the metal salt solutions thoroughly, add 2.5 g of modified mesoporous carbon microspheres, stir for 10 min, let stand for 6 h, filter, and dry to obtain the intermediate product.

[0031] The second step involves adding the intermediate product and 10 times its weight of deionized water to a hydrothermal reactor lined with polytetrafluoroethylene. The reaction is carried out at 150°C for 6 hours. After the reaction is completed, the mixture is cooled to room temperature. The reaction solution is filtered, and the filter cake is washed with distilled water and anhydrous ethanol in sequence. After drying, the precursor powder is obtained.

[0032] The third step is to treat the precursor powder under vacuum conditions at a temperature of 750°C for 5 hours to obtain the multiphase carbide.

[0033] The modified mesoporous carbon microspheres are obtained through the following steps:

[0034] S1. Add 0.5g zirconium dihydrogenide, 100mL anhydrous ethanol and 800mL N,N-dimethylformamide to a flask and sonicate for 1h to obtain a suspension. Add 5g mesoporous carbon microspheres to the suspension and continue sonication for 5min. Then filter and dry the filter cake at 70℃ to constant weight to obtain zirconium dihydrogenide-loaded carbon microspheres.

[0035] S2. Add 0.015 mol citric acid, 0.005 mol trimethylolpropane, 3.5 g supported zirconium dihydrogen phosphate carbon microspheres, 0.07 g p-toluenesulfonic acid and 150 mL N,N-dimethylformamide to the flask. Stir at 100 r / min for 10 min, then heat to 125 °C, control the stirring speed at 220 r / min, and maintain a vacuum of 0.08 MPa. React for 3 h. After the reaction is complete, filter, wash the filter cake three times with anhydrous ethanol, and dry to obtain modified mesoporous carbon microspheres.

[0036] The average particle size of the multiphase carbide obtained in Example 1 was 50 nm, and the oxygen content was 1.34%. The thermogravimetric analysis (DSC) spectrum under air conditions is as follows: Figure 1 As shown, by Figure 1 It can be seen that the obtained multiphase carbides have good antioxidant properties.

[0037] Example 2

[0038] A method for preparing a multiphase carbide includes the following steps:

[0039] Step 1: Weigh out equimolar amounts of the metal salts and dissolve them in 12.5 mL of deionized water. Specifically, the metal salts are 1.6113 g ZrOCl2·8H2O, 1.2001 g Ti(SO4)2, 1.358 g NbCl5, and 0.5849 g NH4VO3. After mixing the metal salt solutions thoroughly, add 2.7 g of modified mesoporous carbon microspheres, stir for 15 min, let stand for 7 h, filter, and dry to obtain the intermediate product.

[0040] The second step involves adding the intermediate product and 12 times its weight of deionized water into a hydrothermal reactor lined with polytetrafluoroethylene. The reaction is carried out at 180°C for 8 hours. After the reaction is completed, the mixture is cooled to room temperature. The reaction solution is filtered, and the filter cake is washed with distilled water and anhydrous ethanol in sequence. After drying, the precursor powder is obtained.

[0041] The third step is to treat the precursor powder under vacuum conditions at a temperature of 850°C for 4.5 hours to obtain the multiphase carbide.

[0042] The modified mesoporous carbon microspheres are obtained through the following steps:

[0043] S1. Add 2g of zirconium dihydrogenate, 120mL of anhydrous ethanol and 830mL of N,N-dimethylformamide to a flask and sonicate for 1h to obtain a suspension. Add 8g of mesoporous carbon microspheres to the suspension and continue sonication for 8min. Then filter and dry the filter cake at 70℃ to constant weight to obtain zirconium dihydrogenate-loaded carbon microspheres.

[0044] S2. Add 0.015 mol citric acid, 0.005 mol trimethylolpropane, 6.5 g supported zirconium dihydrogen phosphate carbon microspheres, 0.07 g p-toluenesulfonic acid and 180 mL N,N-dimethylformamide to the flask. Stir at 150 r / min for 15 min, then heat to 125 °C, control the stirring speed at 220 r / min, maintain a vacuum of 0.08 MPa, and react for 3.5 h. After the reaction is complete, filter, wash the filter cake four times with anhydrous ethanol, and dry to obtain modified mesoporous carbon microspheres.

[0045] The average particle size of the multiphase carbide obtained in Example 2 was 70 nm, and the oxygen content was 1.24%.

[0046] Example 3

[0047] A method for preparing a multiphase carbide includes the following steps:

[0048] Step 1: Weigh out equimolar amounts of the metal salts and dissolve them in 12.5 mL of deionized water, specifically 1.6113 g ZrOCl2·8H2O, 1.2001 g Ti(SO4)2, 1.358 g NbCl5, and 0.5849 g NH4VO3. After mixing the above metal salt solutions thoroughly, add 2.7 g of modified mesoporous carbon microspheres, stir for 20 min, let stand for 8 h, filter, and dry to obtain the intermediate product;

[0049] The second step involves adding the intermediate product and 15 times its weight of deionized water to a hydrothermal reactor lined with polytetrafluoroethylene. The reaction is carried out at 200°C for 10 hours. After the reaction is completed, the mixture is cooled to room temperature. The reaction solution is filtered, and the filter cake is washed with distilled water and anhydrous ethanol in sequence. After drying, the precursor powder is obtained.

[0050] The third step is to treat the precursor powder under vacuum conditions at a temperature of 950°C for 5 hours to obtain the multiphase carbide.

[0051] The modified mesoporous carbon microspheres are obtained through the following steps:

[0052] S1. Add 3g of zirconium dihydrogenate, 160mL of anhydrous ethanol and 850mL of N,N-dimethylformamide to a flask and sonicate for 1h to obtain a suspension. Add 10g of mesoporous carbon microspheres to the suspension and continue sonication for 10min. Then filter and dry the filter cake at 70℃ to constant weight to obtain zirconium dihydrogenate-loaded carbon microspheres.

[0053] S2. Add 0.015 mol citric acid, 0.005 mol trimethylolpropane, 8.5 g supported zirconium dihydrogen phosphate carbon microspheres, 0.07 g p-toluenesulfonic acid and 200 mL N,N-dimethylformamide to the flask. Stir at 200 r / min for 20 min, then heat to 125 °C, control the stirring speed at 220 r / min, and maintain a vacuum of 0.08 MPa. React for 4 h. After the reaction is complete, filter, wash the filter cake 5 times with anhydrous ethanol, and dry to obtain modified mesoporous carbon microspheres.

[0054] The average particle size of the multiphase carbide obtained in Example 3 was 90 nm, and the oxygen content was 1.17%.

[0055] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0056] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for producing a multiphase carbide, characterized by, Comprising the following steps: The first step, four or more transition metal salts containing equal molar amounts of metal cations are weighed and dissolved in water and mixed uniformly to obtain a transition metal salt solution, then modified mesoporous carbon microspheres are added, stirred for 10-20 min, and then left to stand for 6-8 h, filtered, dried, and the intermediate product is obtained; The second step, the intermediate product and deionized water are added to a polytetrafluoroethylene-lined hydrothermal reactor, stirred uniformly, and hydrothermal reaction is carried out, after the reaction is completed, cooled to room temperature, the reaction solution is filtered, the filter cake is washed with distilled water and anhydrous ethanol in turn, dried, and the precursor powder is obtained; The third step, the precursor powder is treated in a vacuum environment at a temperature of 750-950℃ for 4-5h, and the multiphase carbide is obtained. The modified mesoporous carbon microspheres are obtained by the following steps:

2. The method of claim 1, wherein the complex carbide is prepared by the steps of: The amount ratio of the modified mesoporous carbon microspheres and the total metal cations in the transition metal salt in the first step is 12.5-13.5g:1mol.

3. The method of claim 1, wherein the complex carbide is prepared by the steps of: In the second step, the mass ratio of the intermediate product and deionized water is 1:10-15, the hydrothermal reaction temperature is 150-200℃, and the reaction time is 6-10h. ​ 4. The method of claim 1, wherein the complex carbide is prepared by the steps of: The modified mesoporous carbon microspheres are obtained by the following steps: S1, zirconium dihydride, anhydrous ethanol and N,N-dimethylformamide are added to a flask, ultrasonic dispersion is carried out for 1h to obtain a suspension, mesoporous carbon microspheres are added to the suspension, ultrasonic treatment is continued for 5-10min, then filtration is carried out, the filter cake is dried at 70℃ until the weight is constant, and the zirconium dihydride-loaded carbon microspheres are obtained; S2, citric acid, trihydroxymethyl propane, zirconium dihydride-loaded carbon microspheres, p-toluenesulfonic acid and N,N-dimethylformamide are added to a flask, stirring is carried out at a speed of 100-200r / min for 10-20min, then the temperature is raised to 125℃, the stirring speed is controlled at 220r / min, the vacuum degree of the system is 0.08MPa, and reaction is carried out for 3-4h, after the reaction is completed, filtration is carried out, the filter cake is washed with anhydrous ethanol for 3-5 times, and drying is carried out to obtain the modified mesoporous carbon microspheres.

5. The method of claim 4, wherein the complex carbide is prepared by the steps of: The amount ratio of zirconium dihydride, anhydrous ethanol, N,N-dimethylformamide and mesoporous carbon microspheres in S1 is 0.5-3g:100-160mL:800-850mL:5-10g.

6. The method of claim 4, wherein the complex carbide is prepared by the steps of: The amount ratio of citric acid, trihydroxymethyl propane, zirconium dihydride-loaded carbon microspheres, p-toluenesulfonic acid and N,N-dimethylformamide in S2 is 0.015mol:0.005mol:3.5-8.5g:0.07g:150-200mL.

7. A complex carbide characterized by, Prepared by the preparation method of any one of claims 1-6.

8. Use of the multiphase carbide according to claim 7 in the preparation of high-temperature carbide thermal barrier coatings or carbide-reinforced cermet matrix composites.

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