Silicon nitride-bonded silicon carbide refractory material and preparation method thereof

Abstract

The present invention relates to the field of refractory technology, and in particular to a refractory material of silicon nitride combined with silicon carbide and a preparation method thereof, comprising silicon nitride, silicon carbide, aluminum oxide, magnesium oxide, borax, graphite and a binder; wherein the components are, by mass percentage, silicon nitride: 6-51%; silicon carbide: 25-35%; aluminum oxide: 10-20%; magnesium oxide: 5-15%; borax: 3-8%; graphite: 2-6%; binder: 4-10%, the binder being ethyl silicate, polyvinyl alcohol or styrene-butadiene copolymer, the silicon nitride being α-type silicon nitride, the silicon carbide being β-type silicon carbide, and the aluminum oxide being α-type aluminum oxide. The present invention, by combining silicon nitride and silicon carbide, provides excellent high-temperature stability and wear resistance, while possessing excellent chemical stability and low thermal expansion coefficient, and its innovative preparation method ensures the uniformity and high quality of the material, meeting the strict requirements for refractory materials in high-performance industrial applications.

Description

Technical Field

[0001] The present invention relates to the technical field of refractory materials, in particular to a refractory material of silicon nitride combined with silicon carbide and a preparation method thereof. Background Art

[0002] In modern industrial applications, the demand for refractory materials is increasing, especially in high temperature, high pressure and high wear environments. Traditional refractory materials, such as those based on alumina or silicates, although meeting these requirements to a certain extent, are still limited in their performance under extreme conditions. In particular, in terms of high temperature stability, wear resistance and chemical stability, traditional materials often cannot fully meet the increasingly stringent industrial standards.

[0003] At present, the main challenges facing the refractory field include improving the mechanical strength and thermal stability of materials at high temperatures while maintaining good chemical corrosion resistance and low thermal expansion coefficient. In addition, the processing and preparation of materials also face technical difficulties, such as how to ensure uniform mixing of raw materials and how to achieve material stability and consistency through efficient process steps. These challenges limit the use of traditional refractory materials in high-performance applications, especially in aviation, aerospace, nuclear reactors and high-temperature furnaces.

[0004] Therefore, developing a new type of refractory material that can exhibit excellent performance in extreme industrial environments has become an urgent technical need. Summary of the Invention

[0005] Based on the above objectives, the present invention provides a refractory material of silicon nitride combined with silicon carbide and a preparation method thereof.

[0006] A refractory material of silicon nitride combined with silicon carbide, comprising silicon nitride, silicon carbide, aluminum oxide, magnesium oxide, borax, graphite and a binder; wherein the mass percentage of each component is:

[0007] Silicon nitride: 6-51%;

[0008] Silicon carbide: 25-35%;

[0009] Alumina: 10-20%;

[0010] Magnesium oxide: 5-15%;

[0011] Borax: 3-8%;

[0012] Graphite: 2-6%;

[0013] Binder: 4-10%.

[0014] Furthermore, the binder is ethyl silicate, polyvinyl alcohol or styrene-butadiene copolymer, the silicon nitride is α-type silicon nitride, the silicon carbide is β-type silicon carbide, the aluminum oxide is α-type aluminum oxide, and the purity of the magnesium oxide is above 95%.

[0015] A method for preparing a refractory material of silicon nitride combined with silicon carbide comprises the following steps:

[0016] S1: pre-mixing silicon nitride, silicon carbide, aluminum oxide, magnesium oxide, borax, graphite and a binder according to a predetermined weight ratio to form a mixture A;

[0017] S2: wet ball milling the mixture A to form a mixed slurry;

[0018] S3: The mixed slurry is placed in a vacuum environment for drying to remove excess moisture and prevent bubble formation, and then sieved to obtain a powder with a particle size of 10-50 μm;

[0019] S4: The dried powder is pressed into shape in a static press to form a uniform and compact green body structure;

[0020] S5: Pre-sintering treatment is performed in a preset controlled atmosphere;

[0021] S6: sintering the pre-sintered material in a high-temperature hot pressing furnace to form a stable semi-finished refractory material;

[0022] S7: After sintering is completed, the surface of the semi-finished refractory material is laser treated to obtain the finished refractory material.

[0023] Furthermore, the pre-mixing in S1 to form mixture A comprises:

[0024] S11: First, weighed silicon nitride, silicon carbide, aluminum oxide, and magnesium oxide are placed in a high-efficiency mixer and preliminarily dry-mixed at a speed of 200-300 rpm for 5-10 minutes;

[0025] S12: Then, borax and graphite are added to the mixer, and the mixing is continued for 5 minutes while maintaining the same rotation speed as in step S11;

[0026] S14: Finally, slowly add the binder and reduce the speed of the mixer to 100-150 rpm, and mix and stir for 10-15 minutes until the entire mixture reaches a uniform state to form a mixture A.

[0027] Furthermore, the wet ball milling of the mixture A in S2 specifically includes:

[0028] S21: Transfer the mixture A obtained in step S1 into a ball mill, and ensure that the inside of the ball mill is clean and free of impurities;

[0029] S22: adding an appropriate amount of water to the ball mill to form a wet ball milling environment, wherein the volume ratio of the water to the mixture A is 1:1;

[0030] S23: Select zirconia grinding balls with a diameter of 5-10 mm, and control the mass ratio of grinding balls to mixture A to be 3:1;

[0031] S24: setting the rotation speed of the ball mill to 400-600 rpm and performing ball milling for 1-3 hours;

[0032] S25: After the ball milling is completed, the ball-milled slurry is taken out for later use.

[0033] Furthermore, the S3 specifically includes:

[0034] S31: transferring the wet ball-milled mixed slurry obtained in step S2 to a vacuum drying device, and controlling the vacuum degree of the drying device to -0.08 to -0.1 MPa, the drying temperature to 50-70° C., and the drying time to 2-4 hours;

[0035] S32: After drying, the dried mixture is sieved using a sieve with a pore size of 10-50 microns, specifically to ensure that the obtained powder particle size meets the requirements;

[0036] S33: During the screening process, check the screen regularly to prevent clogging.

[0037] Furthermore, the step of pressing the dried powder in a static press in S4 includes:

[0038] S41: Pour the powder obtained after sieving in step S3 evenly into the mold of the static press;

[0039] S42: Pre-press the powder into a mold in a static press. Adjust the pre-pressure of the static press to 10-20 MPa for 30-60 seconds to eliminate air in the powder and ensure uniform distribution of the powder.

[0040] S43: After that, the pressure is increased and the powder is formally pressed into shape in a static press. The pressure is set to 200-300 MPa and the pressing time is controlled to be 1-3 minutes.

[0041] S44: After the pressing is completed, slowly unload the pressure to avoid the green body from being cracked or damaged due to sudden decompression. The unloading time is controlled to 30-50 seconds.

[0042] Furthermore, the controlled atmosphere preset in S5 is nitrogen, argon or helium, and the specific steps of the pre-sintering treatment include:

[0043] S51: first placing the green body obtained in step S4 into a sintering furnace, and setting the atmosphere of the sintering furnace to a preset controlled atmosphere;

[0044] S52: gradually heating to a pre-sintering temperature of 800-1000°C, with the temperature rising rate controlled at 5-10°C / min;

[0045] S53: Pre-sintering at the temperature set in step S52 for 1-3 hours;

[0046] S54: After the pre-sintering is completed, the temperature is slowly lowered to room temperature, and the cooling rate is also controlled at 5-10°C / min.

[0047] Furthermore, a sintering process is performed in S6:

[0048] S61: placing the green body pre-sintered in step S5 into a high-temperature hot press furnace, and setting the sintering temperature of the high-temperature hot press furnace to 1600-1800°C;

[0049] S62: gradually heating up to the set sintering temperature, with the heating rate controlled at 5-15°C / min. After reaching the set temperature, maintaining constant temperature sintering for 2-6 hours;

[0050] S63: After sintering, the temperature is lowered to room temperature at a rate of 5-15°C / min.

[0051] S64: Finally, take out the sintered semi-finished refractory material for use.

[0052] Furthermore, the laser treatment of the surface of the semi-finished refractory material in S7 includes:

[0053] S71: placing the semi-finished refractory material sintered in step S6 into a laser processing device;

[0054] S72: Selecting an appropriate laser type and power setting for surface treatment, wherein the solid-state laser is a Nd:YAG laser with a power setting of 100-500 watts;

[0055] S73: Adjust the focal size and scanning speed of the laser, wherein the focal diameter is 0.1-1.0 mm and the scanning speed is 100-500 mm / s;

[0056] S74: Perform laser scanning processing to ensure that the laser evenly covers the entire surface. After the laser processing, the finished refractory material is obtained.

[0057] Beneficial effects of the present invention:

[0058] The present invention, by combining silicon nitride and silicon carbide, significantly improves performance in extreme high-temperature environments. The thermal stability and wear resistance of this material far exceed those of traditional refractory materials, making it particularly suitable for high-temperature industrial applications such as high-temperature furnaces, aerospace fields and nuclear power facilities. This refractory material can maintain structural and functional integrity under long-term high-temperature exposure, thereby extending the service life of the equipment and reducing maintenance requirements.

[0059] The present invention also has excellent chemical stability and a low thermal expansion coefficient. This property enables the material to remain stable in chemically corrosive environments, such as acidic or alkaline conditions, and is not easily corroded by chemical substances. The low thermal expansion coefficient ensures that the material is dimensionalally stable under temperature changes, reduces stress and deformation caused by temperature, and further improves the reliability and service life of the material.

[0060] The present invention ensures the uniformity and consistency of the refractory material by precisely controlling key steps such as raw material pretreatment, mixing, molding and sintering, thereby improving the quality and performance of the product. In particular, the introduction of the laser surface treatment step brings about a significant improvement in the surface quality of the refractory material and improves the overall performance of the finished product. This method not only improves the performance of the refractory material, but also improves production efficiency and economy. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] In order to more clearly illustrate the technical solutions in the present invention or 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 only for the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0062] Figure 1 Schematic diagram of a method for preparing a refractory material according to an embodiment of the present invention. DETAILED DESCRIPTION

[0063] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to specific embodiments.

[0064] It should be noted that, unless otherwise defined, the technical or scientific terms used in the present invention should have the usual meanings understood by people with ordinary skills in the field to which the present invention belongs. The "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly. Example 1

[0065] like Figure 1 As shown, a refractory material of silicon nitride combined with silicon carbide includes silicon nitride, silicon carbide, aluminum oxide, magnesium oxide, borax, graphite and a binder; wherein the mass percentage of each component is,

[0066] Silicon nitride: 30%;

[0067] Silicon carbide: 30%;

[0068] Alumina: 15%;

[0069] Magnesium oxide: 10%;

[0070] Borax: 5%;

[0071] Graphite: 3%;

[0072] Binder: 7%;

[0073] Borax is used to improve the thermal shock resistance of the material, and graphite is used to improve the thermal conductivity of the material.

[0074] The binder is ethyl silicate, the silicon nitride is α-type silicon nitride, the silicon carbide is β-type silicon carbide, the aluminum oxide is α-type aluminum oxide, and the purity of the magnesium oxide is 98%.

[0075] A method for preparing a refractory material of silicon nitride combined with silicon carbide comprises the following steps:

[0076] S1: pre-mixing silicon nitride, silicon carbide, aluminum oxide, magnesium oxide, borax, graphite and a binder according to a predetermined weight ratio to form a mixture A;

[0077] S2: wet ball milling the mixture A to form a mixed slurry;

[0078] S3: The mixed slurry is placed in a vacuum environment for drying to remove excess moisture and prevent bubble formation, and then sieved to obtain a powder with a particle size of 30 μm;

[0079] S4: The dried powder is pressed into shape in a static press to form a uniform and compact green body structure;

[0080] S5: Pre-sintering treatment is performed in a preset controlled atmosphere to improve the mechanical strength and high temperature resistance of the formed body;

[0081] S6: sintering the pre-sintered material in a high-temperature hot pressing furnace to form a stable semi-finished refractory material;

[0082] S7: After sintering is completed, the surface of the semi-finished refractory material is laser treated to produce the finished refractory material. This step is used to improve the smoothness and wear resistance of the surface. Laser treatment can accurately remove surface defects and enhance the overall performance of the material.

[0083] Pre-mixing is performed in S1 to form a mixture A comprising:

[0084] S11: First, weighed silicon nitride, silicon carbide, aluminum oxide, and magnesium oxide were placed in a high-efficiency mixer and preliminarily dry-mixed at a speed of 250 rpm for 7 minutes to ensure that these hard components were evenly mixed;

[0085] S12: Next, borax and graphite are added to the mixer, and the mixing is continued for 5 minutes while maintaining the same rotation speed as in step S11 to ensure that these auxiliary ingredients are evenly distributed among the hard ingredients;

[0086] S14: Finally, slowly add the binder and reduce the speed of the mixer to 125 rpm, and mix and stir for 10-15 minutes until the entire mixture reaches a uniform state to form a mixture A.

[0087] The wet ball milling treatment of the mixture A in S2 specifically includes:

[0088] S21: Transfer the mixture A obtained in step S1 into a ball mill, and ensure that the inside of the ball mill is clean and free of impurities;

[0089] S22: adding an appropriate amount of water to the ball mill to form a wet ball milling environment, with the volume ratio of water to mixture A being 1:1 to ensure that the mixture is fully wetted during the ball milling process;

[0090] S23: Use 8 mm diameter zirconia grinding balls and control the mass ratio of grinding balls to mixture A to be 3:1 to ensure effective grinding and uniform mixing;

[0091] S24: setting the rotation speed of the ball mill to 500 rpm and performing ball milling for 2 hours;

[0092] S25: After the ball milling is completed, the ball-milled slurry is taken out for later use.

[0093] S3 specifically includes:

[0094] S31: The wet-milled mixed slurry obtained in step S2 is transferred to a vacuum drying device, and the vacuum degree of the drying device is controlled to be -0.09 MPa, the drying temperature is 60° C., and the drying time is 3 hours. Vacuum drying helps to remove excess water in the slurry and prevent the formation of bubbles.

[0095] S32: After drying, the dried mixture is sieved using a 30-micron pore size sieve to ensure that the obtained powder particle size meets the requirements;

[0096] S33: During the screening process, check the screen regularly to prevent clogging and ensure uniform distribution of the powder. The powder after screening should have uniform particle size and good fluidity.

[0097] In S4, the dried powder is pressed into a static press, including:

[0098] S41: Pour the powder obtained after sieving in step S3 evenly into the mold of the static press;

[0099] S42: Pre-press the powder into a mold in a static press. The pre-pressing force of the static press is adjusted to 15 MPa for 45 seconds to eliminate air in the powder and ensure uniform distribution of the powder.

[0100] S43: After that, the pressure is increased and the powder is formally pressed into shape in a static press. The pressure is set to 250 MPa and the pressing time is controlled to 2 minutes to ensure a uniform and compact structure of the green body.

[0101] S44: After the pressing is completed, slowly unload the pressure to avoid the green body from being cracked or damaged due to sudden decompression. The unloading time is controlled to 40 seconds.

[0102] The preset controlled atmosphere in S5 is nitrogen. The specific steps of the pre-sintering process include:

[0103] S51: first placing the green body obtained in step S4 into a sintering furnace, and setting the atmosphere of the sintering furnace to a preset controlled atmosphere to prevent oxidation of the material during the sintering process;

[0104] S52: gradually raising the temperature to a pre-sintering temperature of 900°C, with the temperature rising rate controlled at 7°C / min to avoid thermal stress causing damage to the green body;

[0105] S53: Pre-sintering for 2 hours at the temperature set in step S52, with the time adjusted according to the size and density of the green body;

[0106] S54: After pre-sintering, the green body is slowly cooled to room temperature at a cooling rate of 7°C / minute to prevent cracks or other structural damage caused by rapid cooling. The green body is then removed from the pre-sintered body and inspected to ensure its structural integrity and to prepare for the next sintering process.

[0107] Sintering treatment is performed in S6:

[0108] S61: placing the green body pre-sintered in step S5 into a high-temperature hot pressing furnace, and setting the sintering temperature of the high-temperature hot pressing furnace to 1700° C. This temperature range is conducive to achieving sufficient sintering and crystal growth of the material;

[0109] S62: gradually heating to the set sintering temperature, with the heating rate controlled at 10°C / min. After reaching the set temperature, maintaining the constant temperature for sintering for 4 hours;

[0110] S63: After sintering is completed, the temperature is lowered to room temperature at a rate of 10°C / min.

[0111] S64: Finally, take out the sintered semi-finished refractory material for use.

[0112] Laser treatment of the surface of semi-finished refractory materials in S7 includes:

[0113] S71: placing the semi-finished refractory material sintered in step S6 in a laser processing device, and ensuring accurate alignment and stability of the device for precise surface treatment;

[0114] S72: Select the appropriate laser type and power setting for surface treatment. The solid-state laser is an Nd:YAG laser with a power setting of 300 watts to effectively treat the material surface without causing damage.

[0115] S73: Adjust the focus size and scanning speed of the laser, the focus diameter is 0.5 mm, and the scanning speed is 300 mm / s;

[0116] S74: Perform laser scanning to ensure that the laser evenly covers the entire surface. Depending on the size and shape of the material, multiple scans may be required to process the entire surface. After laser processing, the finished refractory material is obtained. Example 2

[0117] The ingredients ratio is as follows:

[0118] Silicon nitride (α-type): 51%;

[0119] Silicon carbide (β type): 25%;

[0120] Alumina (α type): 10%;

[0121] Magnesium oxide (purity 97%): 5%;

[0122] Borax: 3%;

[0123] Graphite: 2%;

[0124] Binder (polyvinyl alcohol): 4%;

[0125] Specific preparation steps:

[0126] S1: Premixing: Combine silicon nitride, silicon carbide, aluminum oxide, and magnesium oxide. Initially dry mix in a high-efficiency mixer at 200 rpm for 5 minutes. Then add borax and graphite and continue mixing for 5 minutes. Finally, slowly add the binder, reduce the speed to 100 rpm, and mix for 10 minutes.

[0127] S2: Wet ball milling: Transfer the premix to a ball mill, add an equal volume of water, and use 5 mm diameter zirconia balls, maintaining a ball-to-mixture mass ratio of 3:1. Set the ball mill speed to 400 rpm and the milling time to 1 hour.

[0128] S3: Vacuum drying: transfer the ball-milled mixed slurry to a vacuum drying device, set the vacuum degree to -0.08 MPa, the temperature to 50°C, and the drying time to 2 hours. Then, sieve with a 10-micron sieve to ensure that the powder particle size meets the requirements;

[0129] S4: Pressing: Pour the dried powder evenly into the static press mold and pre-press at 10 MPa for 30 seconds to eliminate air and ensure uniform distribution. Then, press at 200 MPa for 1 minute. After the pressing is complete, slowly release the pressure for 30 seconds.

[0130] S5: Pre-sintering treatment: Place the pressed green body in a sintering furnace and gradually heat it to 800°C (heating rate 5°C / min) under an argon atmosphere. The pre-sintering time is set to 1 hour. After the pre-sintering is completed, slowly cool it to room temperature at a cooling rate of 5°C / min.

[0131] S6: Sintering treatment: Place the pre-sintered green body in a high-temperature hot press furnace, set the sintering temperature to 1600°C, and increase the temperature at a rate of 5°C / minute. Sinter at the set temperature for 2 hours. After sintering, cool it down to room temperature at a controlled rate of 5°C / minute.

[0132] S7: Laser treatment, specifically using a Nd:YAG laser to perform surface treatment on the sintered semi-finished product. The laser power is set to 100 watts, the focus diameter is 0.1 mm, and the scanning speed is 100 mm / s to ensure uniform coverage of the entire surface to obtain the finished refractory material. Example 3

[0133] The ingredients ratio is as follows:

[0134] Silicon nitride (α type): 6%;

[0135] Silicon carbide (β type): 35%;

[0136] Alumina (α type): 20%;

[0137] Magnesium oxide (95% purity): 15%;

[0138] Borax: 8%;

[0139] Graphite: 6%;

[0140] Binder (styrene-butadiene copolymer): 10%;

[0141] Specific preparation steps:

[0142] S1: Premixing: Combine silicon nitride, silicon carbide, aluminum oxide, and magnesium oxide. Initially dry mix in a high-efficiency mixer at 300 rpm for 10 minutes. Then add borax and graphite and continue mixing for 5 minutes. Finally, slowly add the binder, reduce the speed to 150 rpm, and mix for 15 minutes.

[0143] S2: Wet ball milling: Transfer the premix to a ball mill, add an equal volume of water, and use 10 mm diameter zirconia balls, maintaining a ball-to-mixture mass ratio of 3:1. Set the ball mill speed to 600 rpm and the milling time to 3 h.

[0144] S3: Vacuum drying: transfer the ball-milled mixed slurry to a vacuum drying device, set the vacuum degree to -0.1 MPa, the temperature to 70°C, and the drying time to 4 hours. Then, sieve with a 50-micron sieve to ensure that the powder particle size meets the requirements;

[0145] S4: Pressing and molding: Pour the dried powder evenly into the static press mold, pre-press and mold it first, set the pre-pressure to 20MPa, and last for 60 seconds to eliminate air and ensure uniform distribution. Then, press it formally, set the pressure to 300MPa, and last for 3 minutes. After the pressing is completed, slowly unload the pressure, and the unloading time is 50 seconds.

[0146] S5: Pre-sintering treatment: Place the pressed green body in a sintering furnace and gradually heat it to 1000°C (heating rate 10°C / min) under a helium atmosphere. The pre-sintering time is set to 3 hours. After the pre-sintering is completed, slowly cool it to room temperature at a cooling rate of 10°C / min.

[0147] S6: Sintering treatment: Place the pre-sintered green body in a high-temperature hot press furnace, set the sintering temperature to 1800°C, and increase the temperature at a rate of 15°C / minute. Sinter at the set temperature for 6 hours. After sintering, cool it down to room temperature at a controlled rate of 15°C / minute.

[0148] S7: Laser treatment, specifically using a Nd:YAG laser to perform surface treatment on the sintered semi-finished product. The laser power is set to 500 watts, the focus diameter is 1.0 mm, and the scanning speed is 500 mm / s to ensure uniform coverage of the entire surface to obtain the finished refractory material.

[0149] Table 1 Comparison of finished product performance parameters .

[0150] As can be seen from Table 1 above, Example 1 has the highest refractoriness (1800°C), which is due to the excellent heat resistance brought about by its high proportion of silicon nitride and silicon carbide. In terms of compressive strength, Example 1 also performs best, showing the superior mechanical stability of the material. Example 1 has the highest thermal conductivity, which indicates that it is more effective in heat conduction and is suitable for applications requiring rapid heat transfer. Example 1 has the highest thermal shock resistance and can withstand more thermal cycles without breaking, showing excellent thermal stability. Example 1 has the strongest wear resistance and the lowest wear rate, which is particularly important for applications in wear environments. Example 1 also performs best in chemical corrosion resistance and is suitable for chemical corrosion environments. Although Example 2 has a lower cost, from the perspective of comprehensive performance, Example 1 provides better cost performance.

[0151] In summary, Example 1 is superior to the other two examples in key performance indicators such as fire resistance, compressive strength, thermal conductivity, thermal shock resistance, wear resistance and chemical corrosion resistance, indicating that it is the best refractory material example. Although its cost is slightly higher than that of Example 2, its excellent comprehensive performance makes it the best choice.

[0152] The present invention is intended to cover all such substitutions, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A refractory material of silicon nitride bonded with silicon carbide, characterized in that: It includes silicon nitride, silicon carbide, aluminum oxide, magnesium oxide, borax, graphite and binder; wherein the mass percentage of each component is: Silicon nitride: 30%; Silicon carbide: 30%; Alumina: 15%; Magnesium oxide: 10%; Borax: 5%; Graphite: 3%; Binder: 7%.

2. The refractory material of silicon nitride bonded with silicon carbide according to claim 1, characterized in that: The binder is ethyl silicate, polyvinyl alcohol or styrene-butadiene copolymer, the silicon nitride is α-type silicon nitride, the silicon carbide is β-type silicon carbide, the aluminum oxide is α-type aluminum oxide, and the purity of the magnesium oxide is above 95%.

3. The method for preparing a refractory material of silicon nitride bonded with silicon carbide according to any one of claims 1 to 2, characterized in that: The following steps are involved: S1: pre-mixing silicon nitride, silicon carbide, aluminum oxide, magnesium oxide, borax, graphite and a binder according to a predetermined weight ratio to form a mixture A; S2: wet ball milling the mixture A to form a mixed slurry; S3: The mixed slurry is placed in a vacuum environment for drying to remove excess moisture and prevent bubble formation, and then sieved to obtain a powder with a particle size of 10-50 μm; S4: The dried powder is pressed into shape in a static press to form a uniform and compact green body structure; S5: Pre-sintering treatment is performed in a preset controlled atmosphere; S6: sintering the pre-sintered material in a high-temperature hot pressing furnace to form a stable semi-finished refractory material; S7: After sintering is completed, the surface of the semi-finished refractory material is laser treated to obtain a finished refractory material.

4. The method for preparing a refractory material of silicon nitride bonded with silicon carbide according to claim 3, characterized in that: The pre-mixing in S1 to form a mixture A comprises: S11: First, weighed silicon nitride, silicon carbide, aluminum oxide, and magnesium oxide are placed in a high-efficiency mixer and preliminarily dry-mixed at a speed of 200-300 rpm for 5-10 minutes; S12: Then, borax and graphite are added to the mixer, and the mixing is continued for 5 minutes while maintaining the same rotation speed as in step S11; S14: Finally, slowly add the binder and reduce the speed of the mixer to 100-150 rpm, and mix and stir for 10-15 minutes until the entire mixture reaches a uniform state to form a mixture A.

5. The method for preparing a refractory material of silicon nitride bonded with silicon carbide according to claim 3, characterized in that: The wet ball milling of the mixture A in S2 specifically includes: S21: Transfer the mixture A obtained in step S1 into a ball mill, and ensure that the inside of the ball mill is clean and free of impurities; S22: adding an appropriate amount of water to the ball mill to form a wet ball milling environment, wherein the volume ratio of the water to the mixture A is 1:1; S23: Select zirconia grinding balls with a diameter of 5-10 mm, and control the mass ratio of grinding balls to mixture A to be 3:1; S24: setting the rotation speed of the ball mill to 400-600 rpm and performing ball milling for 1-3 hours; S25: After the ball milling is completed, the ball-milled slurry is taken out for later use.

6. The method for preparing a refractory material of silicon nitride bonded with silicon carbide according to claim 3, characterized in that: The S3 specifically includes: S31: transferring the wet ball-milled mixed slurry obtained in step S2 to a vacuum drying device, and controlling the vacuum degree of the drying device to -0.08 to -0.1 MPa, the drying temperature to 50-70° C., and the drying time to 2-4 hours; S32: After drying, the dried mixture is sieved using a sieve with a pore size of 10-50 microns, specifically to ensure that the obtained powder particle size meets the requirements; S33: During the screening process, check the screen regularly to prevent clogging.

7. The method for preparing a refractory material of silicon nitride bonded with silicon carbide according to claim 3, characterized in that: The step S4 of pressing the dried powder in a static press comprises: S41: Pour the powder obtained after sieving in step S3 evenly into the mold of the static press; S42: Pre-press the powder into a mold in a static press. Adjust the pre-pressure of the static press to 10-20 MPa for 30-60 seconds to eliminate air in the powder and ensure uniform distribution of the powder. S43: After that, the pressure is increased and the powder is formally pressed into shape in a static press. The pressure is set to 200-300 MPa and the pressing time is controlled to be 1-3 minutes. S44: After the pressing is completed, slowly unload the pressure to avoid the green body from being cracked or damaged due to sudden decompression. The unloading time is controlled to 30-50 seconds.

8. The method for preparing a refractory material of silicon nitride bonded with silicon carbide according to claim 3, characterized in that: The preset controlled atmosphere in S5 is nitrogen, argon or helium, and the specific steps of the pre-sintering treatment include: S51: first placing the green body obtained in step S4 into a sintering furnace, and setting the atmosphere of the sintering furnace to a preset controlled atmosphere; S52: gradually heating to a pre-sintering temperature of 800-1000°C, with the temperature rising rate controlled at 5-10°C / min; S53: Pre-sintering at the temperature set in step S52 for 1-3 hours; S54: After the pre-sintering is completed, the temperature is slowly lowered to room temperature, and the cooling rate is also controlled at 5-10°C / min.

9. The method for preparing a refractory material of silicon nitride bonded with silicon carbide according to claim 3, characterized in that: Sintering is performed in S6: S61: placing the green body pre-sintered in step S5 into a high-temperature hot press furnace, and setting the sintering temperature of the high-temperature hot press furnace to 1600-1800°C; S62: gradually heating up to the set sintering temperature, with the heating rate controlled at 5-15°C / min. After reaching the set temperature, maintaining constant temperature sintering for 2-6 hours; S63: After sintering, the temperature is lowered to room temperature at a rate of 5-15°C / min. S64: Finally, take out the sintered semi-finished refractory material for use.

10. The method for preparing a refractory material of silicon nitride bonded with silicon carbide according to claim 3, characterized in that: The laser treatment of the surface of the semi-finished refractory material in S7 includes: S71: placing the semi-finished refractory material sintered in step S6 into a laser processing device; S72: Select the appropriate laser type and power setting for surface treatment. The solid-state laser is Nd:YAG laser with a power setting of 100-500 watts. S73: Adjust the focal size and scanning speed of the laser, wherein the focal diameter is 0.1-1.0 mm and the scanning speed is 100-500 mm / s; S74: Perform laser scanning processing to ensure that the laser evenly covers the entire surface. After the laser processing, the finished refractory material is obtained.

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