阅读说明：本技术 硝酸盐催化氮化反应赛隆纤维结合碳化硅-刚玉复合耐高温材料的制备方法 (Preparation method of nitrate catalyzed nitridation sialon fiber combined silicon carbide-corundum composite high-temperature-resistant material ) 是由 黄军同 张梦 陈凯 李喜宝 刘玲玉 陈智 于 2020-11-26 设计创作，主要内容包括：本发明的目的在于提供一种硝酸盐催化氮化反应赛隆纤维结合碳化硅-刚玉复合耐高温材料及其制备方法,该方法提供一种以硅粉、铝粉、氧化铝粉体及颗粒,碳化硅粉体及颗粒为原料,以硝酸铁、硝酸钴和硝酸镍其中一种或几种为催化剂,以酚醛树脂为结合剂,通过调控原料配比、原料配料顺序、催化剂添加量、多阶段氮化温度、保温时间、氮气流量等工艺参数和过程,采用催化氮化法制备赛隆反应结合碳化硅-刚玉复合耐高温材料。该方法制备得到的赛隆纤维结合碳化硅-刚玉复合耐高温材料具有氮化温度低、强度高、抗渣侵蚀和抗氧化性能好、寿命长的特点。(The invention aims to provide a sialon fiber combined silicon carbide-corundum composite high-temperature resistant material for nitrate catalytic nitridation reaction and a preparation method thereof. The sialon fiber combined silicon carbide-corundum composite high-temperature resistant material prepared by the method has the characteristics of low nitriding temperature, high strength, good slag corrosion resistance and oxidation resistance and long service life.)

1. A preparation method of a nitrate catalyzed nitridation sialon fiber combined silicon carbide-corundum composite high-temperature resistant material is characterized by comprising the following steps: the preparation method comprises the specific steps of,

firstly, performing dry ball milling on 4-15 wt.% of silicon powder and 5-12 wt.% of alumina fine powder for 0.1-1 hour, preparing 0.01-1 wt.% of catalyst into an aqueous solution with the concentration of 0.1-10%, adding the aqueous solution into the mixed powder, stirring for 0.15-1 hour, and then drying in a blast drying oven at 100-200 ℃ for 3-6 hours;

step two, grinding the dried silicon powder containing the catalyst and the alumina fine powder into fine powder by a ball mill, and then fully mixing the fine powder with the weighed 1.5-4 wt.% of aluminum powder for 0.2-1 hour by ball milling by the ball mill;

step three, sequentially adding 2-10 wt.% of coarse alumina particles, 8-12 wt.% of coarse silicon carbide particles and 4-8 wt.% of binding agent into a stirrer, stirring for 0.1-0.5 hour, then sequentially adding 1-8 wt.% of middle alumina particles, 15-30 wt.% of middle silicon carbide particles, 0-5 wt.% of fine alumina particles, 8-10 wt.% of fine silicon carbide particles, 0-5 wt.% of fine alumina powder, 1-15 wt.% of fine silicon carbide powder and the powder obtained in the step two, and forcibly stirring for 0.3-1.5 hours;

step four, mechanically pressing and molding the fully stirred sample under a friction brick press at the molding pressure of 100-200 MPa, standing the molded sample in a dry and cool and ventilated place for 12-24 hours after pressing, and drying the molded sample in a drying oven at the temperature of 50-110 ℃ for 5-10 hours after standing to obtain a precursor sample;

putting the precursor sample into a nitriding furnace, and sintering under the following nitriding process system: firstly, in the atmosphere of compressed air, the temperature is controlled at a rate of 2-8 ℃ per minute from room temperature^-1Raising the temperature to 180-250 ℃ at the heating rate, and preserving the heat for 3-10 hours; then firstly introducing nitrogenDischarging the air in the furnace for 0.5-3 hours, continuously introducing nitrogen, and then introducing nitrogen at the speed of 2-5 ℃ per minute^-1Raising the temperature rise rate to 600-650 ℃, and preserving the heat for 1-3 hours; then the temperature is controlled at a speed of 2-5 ℃ min^-1Raising the temperature rise rate to 700-750 ℃, and preserving the heat for 1-3 hours; then at 2-8 ℃ for min^-1Raising the temperature rise rate to 1250-1280 ℃, and preserving heat for 1-3 hours; then at 2-5 ℃ for min^-1The temperature of the reaction mixture is raised to 1350-1420 ℃ of the final nitriding sintering temperature, the temperature is kept at the highest temperature for 12-24 hours, and after the nitriding reaction is finished, the reaction mixture is naturally cooled to the room temperature.

The catalyst is one or more of ferric nitrate, cobalt nitrate and nickel nitrate, and is analytically pure.

2. The preparation method of the nitrate-catalyzed nitridation sialon fiber combined silicon carbide-corundum composite high-temperature-resistant material according to claim 1, which is characterized in that: the Si content in the silicon powder is more than or equal to 98 percent, and the particle size is less than or equal to 74 mu m.

3. The method for preparing the nitrate-catalyzed nitridation sialon fiber combined silicon carbide-corundum composite high-temperature-resistant material according to claim 1, wherein the Al content in the aluminum powder is more than or equal to 98%, and the particle size is less than or equal to 45 μm.

4. The preparation method of the nitrate-catalyzed nitridation sialon fiber combined silicon carbide-corundum composite high-temperature-resistant material according to claim 1, which is characterized in that: the alumina powder, Al₂O₃The content is more than or equal to 98 percent, and the grain diameter is less than or equal to 74 mu m.

5. The preparation method of the nitrate-catalyzed nitridation sialon fiber combined silicon carbide-corundum composite high-temperature-resistant material according to claim 1, which is characterized in that: al in the alumina particles₂O₃The content is more than or equal to 98 percent, and the particle size is as follows: the coarse particles are 1-2 mm, the medium particles are 0.5-1.5 mm, and the fine particles are 0-0.5 mm.

6. The preparation method of the nitrate-catalyzed nitridation sialon fiber combined silicon carbide-corundum composite high-temperature-resistant material according to claim 1, which is characterized in that: the SiC content in the silicon carbide powder is more than or equal to 99.5 percent, and the grain diameter is less than or equal to 74 mu m.

7. The method for preparing the nitrate-catalyzed nitridation reaction sialon-silicon carbide-corundum composite high-temperature-resistant material according to claim 1, wherein the content of SiC in the silicon carbide particles is not less than 99.5%, and the particle size is as follows: the coarse particles are 1-2 mm, the medium particles are 0.5-1.5 mm, and the fine particles are 0-0.5 mm.

8. The preparation method of the nitrate-catalyzed nitridation sialon fiber combined silicon carbide-corundum composite high-temperature-resistant material according to claim 1, which is characterized in that: the binding agent is phenolic resin.

9. The method for preparing the nitrate-catalyzed nitridation sialon fiber combined silicon carbide-corundum composite high-temperature-resistant material according to claim 1, wherein the purity of the high-purity nitrogen is more than 99.99%.

10. A nitrate catalyzed nitriding reaction sialon fiber combined silicon carbide-corundum composite high-temperature resistant material is characterized in that: the preparation method of the nitrate catalyzed nitridation sialon fiber combined silicon carbide-corundum composite high temperature resistant material according to any one of claims 1 to 9, wherein a large amount of sialon fibers obtained by the reaction of the catalyst catalyzed silicon powder, alumina powder and aluminum powder are used as reinforcements to strengthen and strengthen the silicon carbide-corundum composite matrix aggregate.

Technical Field

The invention relates to the field of refractory materials, in particular to a nitrate catalyzed nitridation sialon fiber combined silicon carbide-corundum composite high-temperature resistant material and a preparation method thereof.

Background

The high-temperature (fire) resistant material is mainly used in the metallurgical industry, especially the steel industry, the consumption of the high-temperature (fire) resistant material accounts for about 70 percent of the total output of the high-temperature (fire) resistant material, the high-temperature (fire) resistant material is an important basis for the development of the metallurgical industry, the quality and the variety of the high-temperature (fire) resistant material play a key role in the development of high-temperature technology and the steel industry, and the high-temperature (fire) resistant material also makes. The traditional high temperature (fire) resistant material mainly comprises oxides, but has the serious problems that the structure is easy to peel off due to the corrosion and the penetration of slag iron, the temperature field is changed, the internal thermal stress causes damage, molten steel inclusion caused by the dissolution of refractory material components in molten steel seriously affects the steel quality, and the like, and the development of the steel industry can not be met. In recent years, the world's world demand for low-carbon, ultra-low-carbon and high-quality clean steel and the development of external refining process require that the recarburization of molten steel by refractory materials be minimized. The non-oxide composite high-temperature resistant material produced by the method under the background has the excellent performances of high-temperature strength, low pollution to molten steel, good oxidation resistance, thermal shock resistance, slag/alkali corrosion resistance and the like, and is rapidly developed in the ferrous metallurgy industry.

Silicon nitride/sialon (Si) with excellent combination properties₃N₄Sialon) combined silicon carbide (SiC) composite refractory material is a typical representative of non-oxide composite high-temperature-resistant ceramic material, and is used on the inner linings of large and medium-sized blast furnaces in China, so that a good effect is achieved. beta-Sialon (general formula Si)_6-zAl_zO_zN_8-zIn the formula, 0 < z < 4.2) is Al₂O₃Partially substituted with Si by Al and O atoms₃N₄The oxidation resistance of the Si and N atoms in the silicon nitride is superior to that of the Si₃N₄The surface is easy to form a mullite oxide protective film during oxidation; the coefficient of thermal expansion (2.7X 10-6/DEG C) is larger than that of Si₃N₄(3.5X 10-6/deg.C) and, therefore, the Sialon bonded SiC composite has a lower Si content than Si₃N₄The combination of the SiC material with more excellent metal solution corrosion resistance, alkali corrosion resistance, thermal shock resistance and oxidation resistance can obviously improve the number of furnaces used continuously by the material in a blast furnace lining harsh environment. The research and the industrial test of the Luoyang refractory research institute in China prepare 100-ton Sialon bonded SiC bricks, and the research and the industrial test of the Sialon bonded SiC bricks are started in 1992 for the No. 4 blast furnace of saddle steel, so far, the research of the Sialon bonded SiC bricks at home and abroad tends to be mature, and the Sialon bonded SiC bricks mainly aim at prolonging the service life of the lower part of a large-scale blast furnace body, the furnace waist, the furnace belly and the like and the service life of a key furnace lining material for COREX smelting reduction iron-making.

However, in general, the performance of Sialon-bonded SiC refractories has yet to be improved and refined in many ways. First, Sialon bonded SiC bricks are still in need of improvement in oxidation resistance. The high temperature reaction of Sialon in combination with SiC refractory involves the co-oxidation of the Sialon matrix phase and the SiC particle phase, and the Sialon phase surface and SiC particle phase interface is believed to be the primary site for oxidation to occur. Its high temperature oxidation behavior is related to the intrinsic qualities of the materials of the phases and the extrinsic oxidation conditions. And Al₂O₃Has the advantages of good oxidation resistance, high hardness, high strength, high temperature resistance, corrosion resistance and the like, so the Sialon-Al alloy₂O₃the-SiC composite material as a new generation of high-grade refractory material can overcome the defects of respective independent components, and integrates Sialon and Al₂O₃The SiC has excellent performance, and the advantages of the SiC and the SiC can be complemented, so that the SiC has excellent performance and is expected to be applied to high-temperature key parts.

Secondly, the Sialon-SiC refractory material has the problems of large difficulty in industrial preparation, often black core/sandwich (namely incomplete nitridation reaction) and the like when nitridation is carried out at the temperature of more than 1500 DEG CThe product performance is influenced by phenomena such as silicon flow and the like; and the Sialon bonded SiC composite refractory material formed by the in-situ nitridation reaction is prepared by a gas phase reaction, has the technical problems that the product porosity is high, the bonding between a matrix and an aggregate needs to be further strengthened, the strength and the thermal shock resistance of the material need to be further improved, and the like, and needs to be continuously explored and researched by material science and technology workers to solve the technical problems. The scientists at home and abroad have made a lot of efforts to improve the structure, such as Y, mainly by adding some additives₂O₃. Lehongzhi et al research addition Y₂O₃The composite refractory material has the advantages of improving the normal-temperature folding resistance (by 24 percent), the compressive strength (by 7 percent), the oxidation resistance and the thermal shock resistance of the Sialon-SiC composite refractory material product, but reducing the high-temperature strength by 57 percent. The measures ensure that the normal temperature strength is not greatly improved but the high temperature strength is reduced; in addition, rare earth oxides are expensive and limit the scope of application. Therefore, the key to the improvement of the optimized organization structure by seeking a more appropriate method is to improve the compactness of the Sialon-SiC-based composite refractory material, strengthen the matrix and the aggregate, and improve the strength and the thermal shock resistance of the material.

In the last decade, the development of nanotechnology is vigorous, and the adoption of advanced technology to prepare high-purity, cheap and agglomeration-free nanoscale materials and the application of nanotechnology to high-temperature (fire) resistant materials to improve the performance thereof have been the problems considered by related researchers. On the one hand, the nanopowder is introduced directly into the refractory material as a second phase, improving the sinterability and microstructure of the article, thereby strongly affecting the mechanical properties of the article. The nanometer powder is distributed among or in the refractory aggregate particles, so that crystal lattices of the grains are distorted to promote sintering, meanwhile, a plurality of interfaces are formed in the grains, and when the material is stressed to generate cracks, the cracks can be deflected or pinned, thereby improving the fracture strength and toughness of the product, improving the high temperature resistance, and improving the thermal shock resistance and the high temperature creep resistance. Introduction of alpha-Al into high-purity corundum by Jiaxianling et Al₂O₃Adding a small amount of nano Al into the mixture of corundum brick₂O₃And the nano SiO2 can obviously improve the sampleThe mechanical property index of (2). On the other hand, the nanostructures are formed in situ during the preparation of the refractory to improve the refractory properties. E.g. Karamian by reaction with alumino-silicates-Al₂O₃SiC crystal whisker in-situ generated in-C amorphous refractory material can obviously enhance Al₂O₃-C composite refractory strength.

In fact, in Si₃N₄/Sialon bonded Al₂O₃In the microstructure of the-SiC composite refractory, SiC particles or corundum particles are covered with Si₃N₄The sintered nitride is usually wrapped by Sialon matrix, and a network-shaped woven structure is formed by the sintered nitride, so that the mechanical property of the material is improved to a certain extent, and the structure is penetrated among SiC particles, but the improvement effect is limited due to the fact that the fiber and whisker structure is usually in air holes in the material or the product and is low in content. In combination with the latest achievement of the current nano-material new technology in refractory materials, how to increase the whisker content in the materials, especially the content of nano-whiskers, and improve Si content through the structural design₃N₄/Sialon bonded Al₂O₃The compactness of the SiC composite refractory material, the strengthening of the matrix and the aggregate, and the improvement of the strength and the thermal shock resistance of the material are key points.

The transition metal can be used as a catalyst because the unsatisfied d orbital can accept electrons or electron pairs to form a complex, and an active intermediate is formed by the coordination of a ligand and an acceptor, so that the activation energy of the reaction is reduced. Among them, Fe, Co and Ni are proved to be transition metals with highest catalytic activity by a plurality of researches, and are widely applied in the fields of coal gasification catalysis, ethanol gasoline vehicle tail gas purification catalysis, platinum-series bimetallic (Pt/M, M: Fe, Co, Ni) nano catalytic materials and the like. In recent years, Fe, Co, Ni and the like are used as catalysts to carry out deep research on the control of the morphology and the structure of the carbon nanophase, and the carbon nanophase synthesized by adopting transition group metals can obtain carbon nanofiber materials with higher yield and good morphology and structure. The applicant has conducted studies on the phase composition and morphology of the reaction product of nitriding Si powder by catalysts (Fe, Co, Ni) in the past, and found thatThe catalyst can promote the nitridation of Si powder to form Si₃N₄And can promote Si₃N₄And forming whiskers. However, the micro-nano metal catalysts Fe, Co and Ni are easy to agglomerate in the actual production process, are difficult to disperse uniformly, and are easy to form large-particle alloy compounds with Si powder, so that the efficiency of the catalyst is greatly reduced. Therefore, the proper catalyst form is selected to bond Al to Sialon₂O₃The promotion of the formation of Sialon fibers/whiskers by catalyzing the N-N fracture in a reaction system of the-SiC composite refractory material is the key for further promoting the improvement of the comprehensive properties such as the strength of the composite material.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provides a preparation method of a sialon fiber combined silicon carbide-corundum composite high-temperature resistant material, which is low in nitridation reaction temperature, complete in nitridation reaction and excellent in performance and is formed by carrying out catalytic nitridation reaction by taking ferric nitrate/cobalt/nickel as a catalyst. The method comprises the steps of preparing the Sialon fiber-bonded SiC-Al by taking silicon powder, aluminum oxide powder and particles, and silicon carbide powder and particles as raw materials and ferric nitrate, cobalt nitrate and nickel nitrate as catalysts at 1350-1420 ℃ in a nitrogen atmosphere₂O₃A composite high temperature resistant material. The Sialon fiber prepared by the method is combined with SiC-Al₂O₃The composite high-temperature resistant material has low nitriding temperature, high strength, good high-temperature erosion resistance, excellent thermal shock resistance, long service life and good industrialization prospect.

In order to achieve the purpose, the invention adopts the technical scheme that the preparation method of the nitrate catalyzed nitridation sialon fiber combined silicon carbide-corundum composite high-temperature resistant material comprises the following specific steps:

firstly, performing dry ball milling on 4-15 wt.% of silicon powder and 5-12 wt.% of alumina fine powder for 0.1-1 hour, preparing 0.01-1 wt.% of catalyst into an aqueous solution with the concentration of 0.1-10%, adding the aqueous solution into the mixed powder, stirring for 0.15-1 hour, and then drying in a blast drying oven at 100-200 ℃ for 3-6 hours;

step two, grinding the dried silicon powder containing the catalyst and the alumina fine powder into fine powder by a ball mill, and then fully mixing the fine powder with the weighed 1.5-4 wt.% of aluminum powder for 0.2-1 hour by ball milling by the ball mill;

step three, sequentially adding 2-10 wt.% of coarse alumina particles, 8-12 wt.% of coarse silicon carbide particles and 4-8 wt.% of binding agent into a stirrer, stirring for 0.1-0.5 hour, then sequentially adding 1-8 wt.% of middle alumina particles, 15-30 wt.% of middle silicon carbide particles, 0-5 wt.% of fine alumina particles, 8-10 wt.% of fine silicon carbide particles, 0-5 wt.% of fine alumina powder, 1-15 wt.% of fine silicon carbide powder and the powder obtained in the step two, and forcibly stirring for 0.3-1.5 hours;

step four, mechanically pressing and molding the fully stirred sample under a friction brick press at the molding pressure of 100-200 MPa, standing the molded sample in a dry and cool and ventilated place for 12-24 hours after pressing, and drying the molded sample in a drying oven at the temperature of 50-110 ℃ for 5-10 hours after standing to obtain a precursor sample;

putting the precursor sample into a nitriding furnace, and sintering under the following nitriding process system: firstly, under the atmosphere of compressed air, heating from room temperature to 180-250 ℃ at a rate of 2-8 ℃ min < -1 >, and preserving heat for 3-10 hours; then introducing nitrogen for 0.5-3 hours to exhaust air in the furnace, continuously introducing nitrogen, raising the temperature to 600-650 ℃ at a rate of 2-5 ℃ and min-1, and preserving the heat for 1-3 hours; then raising the temperature to 700-750 ℃ at the rate of 2-5 ℃ min < -1 >, and preserving the heat for 1-3 hours; then raising the temperature to 1250-1280 ℃ at the temperature rise rate of 2-8 ℃ min < -1 >, and preserving the heat for 1-3 hours; and then raising the temperature to 1350-1420 ℃ at the rate of 2-5 ℃ min < -1 >, preserving the temperature for 12-24 hours at the highest temperature, and naturally cooling to room temperature after the nitridation reaction is finished.

Preferably, the catalyst is one or more of ferric nitrate, cobalt nitrate and nickel nitrate, and is analytically pure.

Preferably, the Si content in the silicon powder is more than or equal to 98 percent, and the particle size is less than or equal to 74 mu m.

Preferably, the Al content in the aluminum powder is more than or equal to 98 percent, and the particle size is less than or equal to 45 mu m.

Preference is given toThe alumina powder, Al₂O₃The content is more than or equal to 98 percent, and the grain diameter is less than or equal to 74 mu m.

Preferably, the alumina particles contain Al₂O₃The content is more than or equal to 98 percent, and the particle size is as follows: the coarse particles are 1-2 mm, the medium particles are 0.5-1.5 mm, and the fine particles are 0-0.5 mm.

Preferably, the SiC content in the silicon carbide powder is more than or equal to 99.5 percent, and the particle size is less than or equal to 74 mu m;

preferably, the content of SiC in the silicon carbide particles is more than or equal to 99.5%, and the particle size is as follows: the coarse particles are 1-2 mm, the medium particles are 0.5-1.5 mm, and the fine particles are 0-0.5 mm.

Preferably, the binding agent is phenolic resin;

preferably, the high purity nitrogen gas is > 99.99% pure.

The invention also provides a nitrate catalyzed nitriding reaction sialon fiber and silicon carbide-corundum composite high-temperature-resistant material, which is prepared by the preparation method of the nitrate catalyzed nitriding reaction sialon fiber and silicon carbide-corundum composite high-temperature-resistant material, and the nitrate catalyzed nitriding reaction sialon fiber and silicon carbide-corundum composite high-temperature-resistant material is compounded by taking a large amount of sialon fibers obtained by the reaction of catalyst catalytic silicon powder, alumina powder and aluminum powder as reinforcements to strengthen and strengthen the silicon carbide-corundum composite matrix aggregate.

Compared with the prior art, the invention has the following positive effects and prominent characteristics due to the adoption of the technical scheme:

1. the invention adopts one or more of ferric nitrate, cobalt nitrate and nickel nitrate as catalysts, the transition metal nitrates are easy to dissolve in water and are prepared into aqueous solution to be uniformly added into Si powder and Al₂O₃Fine powder raw material is added, so that transition metal ions can be uniformly dispersed in the raw material. Then the moisture is removed through heat treatment at about 100-200 ℃, so that the moisture and the subsequently added raw material Al powder are prevented from being hydrated. In the method, transition metal nitrate dissolved in water is used instead of micro-nano metal particles, so that the agglomeration of directly used metals is avoided, catalytic active sites can be effectively utilized to the maximum extent, and the catalytic efficiency of the catalyst is greatly improved; meanwhile, aqueous solution in the form of transition metal nitrate is used as a catalyst, and compared with the method adopting micro-nano solid Fe,The Co powder and the Ni powder have better dispersion effect and catalytic nitridation efficiency, under the same efficiency, the content of the transition metal actually participating in the reaction is far less than that of the transition metal particles directly used, the catalyst agglomeration and the residue in the product can be reduced, and the Sialon-Al is improved₂O₃Physical properties of the SiC refractory composite. Transition metal nitrate is used as a catalyst, so that the nitridation reaction of the raw materials can be promoted, the nitridation reaction temperature is reduced, and the reaction time is shortened;

2. according to the invention, iron nitrate, cobalt nitrate and nickel nitrate with low price are added as catalysts, so that the nitridation reaction of the raw materials is promoted, the sintering temperature and reaction time of the nitridation reaction are reduced, and energy is saved; and the rare earth oxide which is an expensive sintering aid is replaced, so that the cost is reduced.

3. According to the invention, ferric nitrate, cobalt nitrate and nickel nitrate are added as catalysts to promote the nitridation of silicon powder, aluminum powder and alumina powder and form a large amount of Sialon nano fibers, and the Sialon nano fibers can obviously improve the prepared Sialon combined SiC-Al₂O₃Physical properties of the composite high temperature resistant material.

4. The invention selects a specific nitriding process system to sinter, and the sintering is carried out at 180-250 ℃ for 1-3 hours in the atmosphere of compressed air, so as to treat the dehydration of the binding agent phenolic resin; raising the temperature to 600-650 ℃ in nitrogen, and preserving the heat for 1-3 hours, so that the metal aluminum powder can be nitrided to form aluminum nitride and the phenomenon of aluminum flowing is overcome; continuously heating to 700-750 ℃ and preserving heat for 1-3 hours, so as to carbonize the phenolic resin, wrap the particles and improve the erosion resistance of the material; raising the temperature to 1250-1280 ℃ and preserving the heat for 1-3 hours so as to ensure that the silicon powder is gradually nitrided to overcome the phenomenon of silicon flowing; these particular nitridation sintering processes can improve the overall performance of the material.

5. In the invention, ferric nitrate, cobalt nitrate and nickel nitrate are added as catalysts, so that the nitridation reaction of the raw materials is promoted, the problem that the nitridation reaction is difficult to completely generate 'black core/sandwich' in the preparation process of Sialon is solved, and the obtained Sialon is combined with SiC-Al₂O₃The apparent porosity of the composite high-temperature resistant material is 12.3-13.1%, the volume density is 2.85-2.98 g/cm3,the normal-temperature flexural strength is 50-65 MPa, and the high-temperature flexural strength at 1400 ℃ is as follows: 50-60MPa, and 255-280 MPa in compressive strength, and the prepared Sialon fiber combined SiC-Al₂O₃The composite high-temperature resistant material has more excellent strength, oxidation resistance, thermal shock resistance stability and slag erosion resistance.

Drawings

The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

FIG. 1 is a Sialon fiber-bonded SiC-Al prepared by adding 1.0 wt.% ferric nitrate to example 1₂O₃XRD pattern of the composite high temperature resistant material;

FIG. 2 is a Sialon fiber-bonded SiC-Al prepared by adding 0.2 wt.% cobalt nitrate to example 2₂O₃SEM photo of the composite high temperature resistant material cross section;

FIG. 3 is a Sialon fiber-bonded SiC-Al prepared by adding 0.2 wt.% cobalt nitrate to example 2₂O₃SEM photograph of a plurality of fibers in the section of the composite high-temperature resistant material.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more clear, the following embodiments of the present invention are further described in detail, but the scope of the present invention is not limited thereby.

The present invention will be described in further detail with reference to specific examples.

The method comprises the steps of weighing according to the Sialon molecular formula and the raw material proportioning rule of the refractory composite material, pretreating the catalyst and the raw materials to fully mix the catalyst and the fine powder raw materials, and forcibly stirring and uniformly mixing the particle raw materials, the bonding agent and the fine powder raw materials in a stirrer. And then pressing and molding the fully stirred raw materials in a friction brick press, standing, drying, and finally putting the sample into a nitriding furnace to be subjected to nitriding firing in a nitrogen atmosphere.

The present invention will be described in more detail below with reference to specific examples, but these examples are only for the purpose of facilitating understanding of the present invention and the present invention is not limited to these examples.

In order to avoid repetition, the raw materials related to this specific embodiment are uniformly described as follows, and are not described in detail in the embodiments:

the Si content in the silicon powder is more than or equal to 98 percent, and the particle size is less than or equal to 74 mu m.

The Al content in the aluminum powder is more than or equal to 98 percent, and the particle size is less than or equal to 45 mu m.

Al in the alumina powder₂O₃The content is more than or equal to 98 percent, and the grain diameter is less than or equal to 74 mu m.

Al in the alumina particles₂O₃The content is more than or equal to 98 percent, and the particle size is as follows: the coarse particles are 1-2 mm, the medium particles are 0.5-1.5 mm, and the fine particles are 0-0.5 mm.

The SiC content in the silicon carbide powder is more than or equal to 99.5 percent, and the grain diameter is less than or equal to 74 mu m.

The SiC content in the silicon carbide particles is more than or equal to 99.5 percent, and the particle size is as follows: the coarse particles are 1-2 mm, the medium particles are 0.5-1.5 mm, and the fine particles are 0-0.5 mm.

The catalyst is ferric nitrate Fe (NO)₃)₂·9H₂O, cobalt nitrate Co (NO)₃)₂·6H₂O, nickel nitrate Ni (NO)₃)₂·6H₂And one or more of O is analytically pure.

The binding agent is phenolic resin.

Example 1

According to the formula Si_6-zAl_zO_zN_8-z(wherein z is 4) and Fe (NO) is used as the catalyst₃)₂·9H₂And when O is obtained, the weighed raw materials and the total ingredients of the raw materials are shown in the table 1 after calculation according to the proportioning principle:

table 1 ingredient ratio (wt.%) of each raw material

Firstly, carrying out dry ball milling on 14 wt.% of silicon powder and 8.7 wt.% of alumina fine powder for 0.5 hour, preparing 1.0 wt.% of catalyst into 8% aqueous solution, adding the aqueous solution into the mixed powder, stirring for 0.3 hour, and then drying for 3 hours in a blast drying oven at 100 ℃;

step two, grinding the dried silicon powder containing the catalyst and the alumina fine powder into fine powder by a ball mill, and then fully mixing the fine powder with weighed 2.3 wt.% aluminum powder for 0.5 hour by the ball mill;

step three, sequentially adding 4 wt.% of alumina coarse particles, 9.0 wt.% of silicon carbide coarse particles and 7 wt.% of bonding agent into a stirrer, sequentially adding 6 wt.% of alumina medium particles, 30 wt.% of silicon carbide medium particles, 4 wt.% of alumina fine particles, 9.0 wt.% of silicon carbide fine particles, 5 wt.% of silicon carbide fine powder and the powder obtained in the step two after stirring for 0.2 hour, and forcibly stirring for 0.5 hour;

step four, mechanically pressing and molding the fully stirred sample under a friction brick press at the molding pressure of 150MPa, placing the molded sample in a dry and cool and ventilated place for standing for 12 hours after pressing, and placing the molded sample in a drying oven for drying for 6 hours at the temperature of 80 ℃ after standing to obtain a precursor sample;

putting the precursor sample into a nitriding furnace, and sintering under the following nitriding process system: first of all, under an atmosphere of compressed air, from room temperature at a rate of 2 ℃ min^-1Raising the temperature to 180 ℃ at the heating rate, and preserving the heat for 3 hours; then nitrogen was introduced for 1 hour to exhaust the air in the furnace, and nitrogen was continuously introduced, followed by a rate of 2. min^-1Raising the temperature to 600 ℃ at the heating rate, and keeping the temperature for 1 hour; followed by a rate of 2 ℃ min^-1Raising the temperature to 700 ℃ at the heating rate, and keeping the temperature for 1 hour; then at 2 ℃ min^-1The temperature rising rate is increased to 1250 ℃, and the temperature is preserved for 1 hour; then at 2 ℃ min^-1The rate of the reaction is increased to the final nitriding sintering temperature of 1420 ℃, the temperature is kept for 12 hours at the highest temperature, and after the nitriding reaction is finished, the reaction product is naturally cooled to the room temperature, and the Sialon combined SiC-Al is obtained₂O₃A composite high temperature resistant material.

Example 2

According to the formula Si_6-zAl_zO_zN_8-z(wherein z is 3.8) and Co (NO) is used as the catalyst₃)₂·6H₂When O is added, the raw materials and the total ingredients are calculated according to the proportioning principle, and the weighed raw materials and the total ingredients are shown in Table 2：

Table 2 ingredient ratio (wt.%) of each raw material

Firstly, carrying out dry ball milling on 13 wt.% of silicon powder and 8.5 wt.% of alumina fine powder for 0.2 hour, preparing 0.2 wt.% of catalyst into 10% aqueous solution, adding the aqueous solution into the mixed powder, stirring for 0.5 hour, and then drying for 5 hours in a blast drying oven at 120 ℃;

step two, grinding the dried silicon powder containing the catalyst and the alumina fine powder into fine powder by a ball mill, and then fully mixing the fine powder with weighed 2.5 wt.% aluminum powder for 0.3 hour by the ball mill;

step three, sequentially adding 7 wt.% of coarse alumina particles, 11.5 wt.% of coarse silicon carbide particles and 5 wt.% of binding agent into a stirrer, stirring for 0.3 hour, then sequentially adding 8 wt.% of middle alumina particles, 20.8 wt.% of middle silicon carbide particles, 5 wt.% of fine alumina particles, 9.5 wt.% of fine silicon carbide particles, 10 wt.% of fine silicon carbide powder and the powder obtained in the step two, and forcibly stirring for 1 hour;

step four, mechanically pressing and molding the fully stirred sample under a friction brick press at the molding pressure of 180MPa, placing the molded sample in a dry and cool and ventilated place for standing for 18 hours, and placing the molded sample in a drying oven for drying for 8 hours at 100 ℃ after standing to obtain a precursor sample;

putting the precursor sample into a nitriding furnace, and sintering under the following nitriding process system: first of all, under an atmosphere of compressed air, from room temperature at a rate of 4 ℃ min^-1Raising the temperature to 200 ℃ at the heating rate, and keeping the temperature for 2 hours; then nitrogen was introduced for 0.5 hour to allow the air in the furnace to escape, and nitrogen was continuously introduced, followed by a rate of 3. min^-1Raising the temperature to 650 ℃ at the heating rate, and keeping the temperature for 0.5 hour; then at a rate5℃·min^-1Raising the temperature to 700 ℃ at the heating rate, and keeping the temperature for 1 hour; then at 2 ℃ min^-1The temperature rising rate is increased to 1280 ℃, and the temperature is kept for 1 hour; then at 2 ℃ min^-1The rate of the reaction is increased to 1380 ℃ of the final nitriding sintering temperature, the temperature is kept for 15 hours at the highest temperature, and after the nitriding reaction is finished, the reaction product is naturally cooled to room temperature to obtain the Sialon bonded SiC-Al₂O₃A composite high temperature resistant material.

Example 3

According to the formula Si_6-zAl_zO_zN_8-z(wherein z is 2) and Ni (NO) is used as the catalyst₃)₂·6H₂And when O is obtained, the weighed raw materials and the total ingredients of the raw materials are shown in the following table 3 after calculation according to the proportioning principle:

table 3 ingredient ratio (wt.%) of each raw material

Firstly, performing dry ball milling on 4.9 wt.% of silicon powder and 11.9 wt.% of alumina fine powder for 0.6 hour, preparing 0.8 wt.% of catalyst into 6% aqueous solution, adding the aqueous solution into the mixed powder, stirring for 0.5 hour, and then drying for 5 hours in a blast drying oven at 100 ℃;

step two, grinding the dried silicon powder containing the catalyst and the alumina fine powder into fine powder by a ball mill, and then fully mixing the fine powder with weighed 3.2 wt.% aluminum powder for 0.6 hour by the ball mill;

step three, sequentially adding 6 wt.% of coarse alumina particles, 9.5 wt.% of coarse silicon carbide particles and 6 wt.% of binding agent into a stirrer, sequentially adding 8 wt.% of middle alumina particles, 28.7 wt.% of middle silicon carbide particles, 6 wt.% of fine alumina particles, 8.5 wt.% of fine silicon carbide particles, 6.5 wt.% of fine silicon carbide powder and the powder obtained in the step two after stirring for 0.3 hour, and forcibly stirring for 1 hour;

step four, mechanically pressing and molding the fully stirred sample under a friction brick press at the molding pressure of 180MPa, placing the molded sample in a dry and cool and ventilated place for standing for 12 hours, and placing the molded sample in a drying oven for drying for 8 hours at 110 ℃ after standing to obtain a precursor sample;

putting the precursor sample into a nitriding furnace, and sintering under the following nitriding process system: first of all, under an atmosphere of compressed air, from room temperature at a rate of 2 ℃ min^-1Raising the temperature to 200 ℃ at the heating rate, and preserving the heat for 3 hours; then nitrogen was first passed for 1.5 hours to allow the air in the furnace to escape, nitrogen was continued to be passed, and then at a rate of 2 min^-1Raising the temperature to 650 ℃ at the heating rate, and keeping the temperature for 1 hour; followed by a rate of 2 ℃ min^-1Raising the temperature to 700 ℃ at the heating rate, and keeping the temperature for 1 hour; then at 2 ℃ min^-1The temperature rising rate is increased to 1260 ℃, and the temperature is kept for 1 hour; then at 2 ℃ min^-1The rate of the reaction is increased to the final nitriding sintering temperature of 1400 ℃, the temperature is kept at the highest temperature for 12 hours, and after the nitriding reaction is finished, the reaction product is naturally cooled to the room temperature to obtain the Sialon bonded SiC-Al₂O₃A composite high temperature resistant material.

Example 4

According to the formula Si_6-zAl_zO_zN_8-z(wherein z is 4.1) and Co (NO) is used as the catalyst₃)₂·6H₂O and Ni (NO)₃)₂·6H₂And when O is obtained, the weighed raw materials and the total ingredients of the raw materials are shown in the table 4 after calculation according to the proportioning principle:

table 4 ingredient ratio (wt.%) of each raw material

Firstly, carrying out dry ball milling on 15 wt.% of silicon powder and 7.9 wt.% of alumina fine powder for 0.3 hour, preparing 0.5 wt.% of catalyst into 9% aqueous solution, adding the aqueous solution into the mixed powder, stirring for 0.4 hour, and drying for 4 hours in a blast drying oven at 120 ℃;

step two, grinding the dried silicon powder containing the catalyst and the alumina fine powder into fine powder by a ball mill, and then fully mixing the fine powder with weighed 3.1 wt.% aluminum powder for 0.5 hour by the ball mill;

step three, sequentially adding 5 wt.% of alumina coarse particles, 8.5 wt.% of silicon carbide coarse particles and 6 wt.% of binding agent into a stirrer, sequentially adding 6 wt.% of alumina medium particles, 28 wt.% of silicon carbide medium particles, 5 wt.% of alumina fine particles, 9.0 wt.% of silicon carbide fine particles, 6 wt.% of silicon carbide fine powder and the powder obtained in the step two after stirring for 0.3 hour, and forcibly stirring for 0.5 hour;

step four, mechanically pressing and molding the fully stirred sample under a friction brick press at the molding pressure of 180MPa, placing the molded sample in a dry and cool and ventilated place for standing for 12 hours after pressing, and placing the molded sample in a drying oven for drying for 5 hours at 100 ℃ after standing to obtain a precursor sample;

putting the precursor sample into a nitriding furnace, and sintering under the following nitriding process system: first of all, under an atmosphere of compressed air, from room temperature at a rate of 2 ℃ min^-1Raising the temperature to 200 ℃ at the heating rate, and keeping the temperature for 2.5 hours; then nitrogen was introduced for 1 hour to exhaust the air in the furnace, and nitrogen was continuously introduced, followed by a rate of 2. min^-1Raising the temperature to 600 ℃ at the heating rate, and keeping the temperature for 1 hour; followed by a rate of 2 ℃ min^-1Raising the temperature to 700 ℃ at the heating rate, and keeping the temperature for 1 hour; then at 2 ℃ min^-1The temperature rising rate is increased to 1280 ℃, and the temperature is kept for 2 hours; then at 2 ℃ min^-1The rate of the reaction is increased to 1350 ℃ of the final nitriding sintering temperature, the temperature is kept for 18 hours at the highest temperature, and after the nitriding reaction is finished, the reaction product is naturally cooled to room temperature to obtain the Sialon bonded SiC-Al₂O₃A composite high temperature resistant material.

The embodiments of the present invention are not limited to the above-described embodiments, and other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and are intended to be included in the scope of the present invention.

The above examples are merely illustrative for clearly illustrating the present invention and are not intended to limit the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.