Preparation method of SiC / Cu-based composite material with three-dimensional network structure for improving wear resistance of blast-furnace tuyere

Abstract

The problems that a blast-furnace tuyere is poor in wear resistance and short in service life under harsh working conditions, the tuyere is frequently replaced, the production efficiency and the smelting quality are greatly reduced, and meanwhile the cost is increased are solved. The invention provides a preparation method of a SiC / Cu-based composite material with a three-dimensional network structure for improving the wear resistance of a blast-furnace tuyere. According to the method, a pressureless infiltration process is adopted, the three-dimensional net-shaped silicon carbide ceramic reinforced copper-based composite material is prepared on the inner surface of the blast-furnace tuyere, and the wear resistance and the thermal shock resistance of the tuyere are remarkably improved. By optimizing a silicon carbide slurry formula and performing vacuum impregnation on aluminum oxide slurry, the strength of the ceramic framework and the toughness of the metal matrix are further improved, and the ceramic framework and the metal matrix form a complementary composite structure, so that the overall durability of the material is enhanced. Compared with a traditional pure copper tuyere, the wear resistance of the composite material is improved by 9.2-10.5 times, and the composite material is suitable for a severe high-temperature and high-pressure smelting environment. The technical problem that an existing tuyere is prone to melting loss and abrasion is solved, the service life of the tuyere is remarkably prolonged, the replacement frequency is reduced, and therefore the use cost is reduced, and the production efficiency is improved. In addition, compared with an existing complex wear-resistant coating process, the non-pressure infiltration and vacuum impregnation process is simpler, more convenient, moderate in cost and suitable for large-scale industrial production and application.

Description

Technical Field

[0001] The invention belongs to the field of preparation of high-wear-resistant blast furnace tuyere sleeves, and in particular relates to a method for preparing a three-dimensional network structure (3D-N) SiC / Cu-based composite material for improving the wear resistance of a blast furnace tuyere. The three-dimensional network structure SiC / Cu-based composite material is prepared on the inner surface of the blast furnace tuyere by a pressureless infiltration method, thereby improving the wear resistance of a traditional pure copper blast furnace tuyere. Background Art

[0002] In the process of steelmaking and ironmaking, the blast furnace tuyere is responsible for delivering high-temperature hot air to the blast furnace and providing oxygen to meet the needs of pig iron smelting. As a key component of the blast furnace air supply system, the tuyere not only undertakes heat exchange, but also has important functions such as cooling. The tuyere lining is close to the high-temperature combustion zone and is in the blast furnace hearth at about 2000°C for a long time. It must withstand the melting and impact wear of liquid slag and high-temperature coke. With the increase in coal injection, slag splashing and iron flow ablation, the inner wall of the tuyere is subjected to more severe scouring and impact. Such harsh working conditions make the tuyere extremely prone to melting and wear, significantly shortening its service life. Frequent replacement of tuyere will not only reduce the production efficiency of the blast furnace, but may also affect the smelting quality due to fluctuations in working conditions. Therefore, the service life of the tuyere is directly related to the stable operation, production efficiency and production cost of the blast furnace.

[0003] At present, large domestic steel companies generally use copper materials with high thermal conductivity and excellent heat dissipation performance to manufacture blast furnace tuyere. However, due to the poor wear resistance of copper, the service life of the tuyere is still difficult to reach the ideal level. In order to improve the wear resistance of the tuyere material, researchers have tried a variety of technologies, including surfacing, plasma spraying, laser cladding and ceramic inlay. The document with Chinese patent publication number CN202671556U discloses "A Highly Wear-Resistant Blast Furnace Tuyere Sleeve", which improves its wear resistance and service life by inlaying a thin layer of wear-resistant sheet on the inner ring surface of the tuyere sleeve. The document with Chinese patent publication number CN217418735U proposes a "New Tuyere Small Sleeve", which significantly improves the wear resistance of the tuyere small sleeve by machining a grid groove on the front surface of the tuyere and filling it with a high-hardness wear-resistant alloy layer. However, these processes often have problems such as too thin wear-resistant layer, complex process, expensive equipment, insufficient bonding strength between the substrate and the wear-resistant layer, and easy falling off, which limits its wide application in industry.

[0004] In view of the harsh working conditions of the tuyere and the shortcomings of the existing technology, it is urgent to develop a new process that is simple, moderately expensive and can significantly extend the service life of the tuyere. This research group proposed to use three-dimensional network silicon carbide ceramics as the reinforcing matrix, and to prepare a three-dimensional network structure SiC / Cu-based composite material on the inner surface of the tuyere through a pressureless infiltration process. The three-dimensional network silicon carbide ceramic runs through the entire metal matrix to form a uniformly and continuously distributed two-phase structure. The ceramic skeleton is toughened by the good plasticity and toughness of the metal matrix, and the metal phase is strengthened by the rigid support of the ceramic skeleton. The two rely on each other and reinforce each other to form a stable support structure. Compared with traditional particle-reinforced, fiber-reinforced and whisker-reinforced composite materials, the SiC / Cu-based composite material exhibits better mechanical properties and wear resistance, and the process is relatively simple and the cost is moderate. By optimizing the preparation process of three-dimensional network structure silicon carbide ceramics, the performance of silicon carbide ceramics in the vacuum impregnation process and the performance of the three-dimensional network SiC / Cu-based composite material formed are improved, and the wear resistance is improved to meet the requirements of industrial applications. Summary of the invention

[0005] The present invention provides a method for preparing a three-dimensional mesh structure SiC / Cu-based composite material for improving the wear resistance of a blast furnace tuyere. By designing the inner lining of the blast furnace tuyere, the tuyere can not only be effectively protected, but also its wear resistance can be significantly improved while maintaining high thermal conductivity, thereby greatly improving the wear resistance and service life of the tuyere.

[0006] Measures to achieve the above objectives:

[0007] A method for preparing a three-dimensional mesh structure SiC / Cu-based composite material for improving the wear resistance of a blast furnace tuyere mainly comprises the following steps:

[0008] 1) Preparation of SiC slurry: First, the raw materials required for the experiment were weighed in proportion and poured into a stirrer for premixing. Next, the additives were weighed and completely dissolved in deionized water, and the deionized water containing the additives was added dropwise to the premixed raw materials, and the slurry was stirred continuously until the slurry was uniform, thereby obtaining a silicon carbide slurry with excellent thixotropy, fluidity and viscosity.

[0009] 2) Preparation of three-dimensional network structure SiC blank: The cut polyurethane foam is fully immersed in silicon carbide slurry, and then placed on a roller press to squeeze out excess slurry. To ensure the porosity of the 3D-N SiC preform, the extrusion height of the press roller is set to 15-20% of the thickness of the polyurethane foam. Subsequently, an air compressor is used to blow open the blocked pores and distribute the slurry as evenly as possible on the three-dimensional network polyurethane skeleton, thereby obtaining a high-porosity 3D-N SiC blank;

[0010] 3) Preparation of 3D-N SiC preform by secondary high-pressure spraying of silicon carbide slurry: The secondary spraying uses silicon carbide slurry with the same formula as the primary slurry and mixes it evenly in a cement mixer. The difference is that a small amount of deionized water needs to be added to the slurry for the secondary spraying to ensure that the slurry can be sprayed evenly in the high-pressure spray pot. After the secondary high-pressure spraying slurry is prepared, it is loaded into a high-pressure spray pot and sprayed on the sample after the primary slurry treatment, so that the slurry is evenly covered on the silicon carbide skeleton as much as possible, and the blocked holes are reopened by high-pressure treatment to ensure that the preform has a high porosity. After spraying, the blank is naturally air-dried for 18 to 24 hours, and then placed in a drying oven at 100 to 115°C for 10 to 14 hours. The dried green blank is placed in a T-1700 high-temperature sintering furnace for sintering, and the heating program is as follows: heating from room temperature to 600°C at 1-2°C / min, and keeping warm for 80-100min; heating from 600°C to 800°C at 2-4°C / min, and keeping warm for 0.5-1.5h; heating from 800°C to 1450°C at 5-8°C / min, keeping warm for 2-4h, and then cooling with the furnace, and finally obtaining a 3D-N SiC preform SI1;

[0011] 4) Preparation of vacuum impregnation reinforced 3D-N SiC preform: Weigh the alumina slurry containing andalusite in proportion and pour it into a corundum tank, and add an appropriate amount of deionized water for premixing. Then ball mill it on a ball mill at a speed of 250-300 rpm for 2-4 hours to obtain an alumina slurry containing andalusite for vacuum impregnation. The 3D-N SiC preform is completely immersed in the vacuum impregnation slurry, and placed in a vacuum box together, evacuated to a vacuum state of 0.5-1 Pa and maintained at a pressure of 25-30 minutes. After taking out the sample, let it air dry naturally and dry it at 100-115°C. Subsequently, the sample is placed in a high-temperature sintering furnace, sintered at 1400-1450°C, cooled to room temperature with the furnace and taken out, and the sample is named SI2;

[0012] 5) Design and preparation of resin sand mold: Sand casting is divided into an upper mold and a lower mold, in which the upper mold is provided with a pouring riser, which will be cut off after the sample is formed. The lower mold is provided with a cavity that matches the size of the 3D-N SiC ceramic, which is convenient for the metal liquid to fill and form the metal matrix composite material. It is particularly important to note that a draft angle of 1 to 3° should be set in the riser and the cavity. The resin sand mold uses 40 to 70 mesh resin sand as the molding material, and resin and curing agent as additives, and is proportioned according to the ratio of resin sand: resin: curing agent = 90 to 100: 1 to 1.2: 0.3 to 0.6. The specific process is: first, mix the resin sand and curing agent for 3 to 5 minutes, and after mixing evenly, add the resin and stir quickly. Subsequently, the mixture is poured into the mold, and the resin and curing agent react, causing the sand mold to harden and form the mold;

[0013] 6) Preparation of 3D-N SiC / Cu-based composite materials by sand casting: The 3D-N SiC preform SI2 is placed in the lower mold, and then the upper mold is closed, and the design method is adopted that the size of the gate channel at the bottom of the upper mold is smaller than the size of the cavity. Subsequently, the matrix material T2 pure copper is heated to 1135-1200°C in a crucible resistance furnace, and after it is completely melted, it is poured into a resin sand casting mold containing SI2, and taken out after cooling to room temperature. The SiC / Cu-based composite material prepared by the preform is named SI22. The 3D-N SiC preform SI2 is placed in the lower mold, and then the upper mold is closed, and the design method is adopted that the size of the gate channel at the bottom of the upper mold is smaller than the size of the cavity. Next, the T2 pure copper matrix material is heated to 1135-1200°C in a crucible resistance furnace, and after it is completely melted, it is quickly poured into a resin sand mold containing SI2. After cooling to room temperature, the sample is taken out, and the obtained SiC / Cu-based composite material is named SI22.

[0014] The experimental raw material composition and weight percentage content in the SiC slurry are: silicon carbide (SiC): 75.0-85.0%, α-alumina (α-Al 2 O 3 ): 13.0~14.5%, silicon dioxide (SiO 2 ): 5.5-6.0%; the additive composition and weight percentage content are: carboxymethyl cellulose (CMC): 0.1-0.4%, ammonium lignin sulfonate (AM): 1.0-2.0%, polycarboxylate (FS65): 0.1-0.3%, and the rest is water. In addition, CMC is a thickener, AM is a binder, and FS65 is a dispersant.

[0015] The vacuum impregnation of alumina slurry containing andalusite has the following composition and weight percentage: α-alumina (α-Al 2 O 3 ): 75.5~80.0%, andalusite (Al 2 SiO 5 ): 20.0~25.0%; the composition and weight percentage content of the additives are: polycarboxylate (FS65): 0.1~0.3%, and the rest is water.

[0016] Function and mechanism of the main process in the present invention

[0017] The reason why the content of dispersant FS65 is controlled at 0.1-0.3% in the present invention is that silicon carbide slurry is a typical pseudoplastic fluid. As the amount of FS added increases from 0.1wt% to 0.3wt%, the viscosity of the slurry gradually decreases; as the content of FS continues to increase, the viscosity of the silicon carbide slurry tends to increase. Within this range, FS65 has the best fluidity as a dispersant for silicon carbide slurry.

[0018] The reason why the content of ammonium lignin sulfonate (AM) is controlled between 1.0% and 2.0% in the present invention is mainly because the shear stress of silicon carbide slurry increases with the increase of shear rate, but the growth amplitude of stress gradually decreases. The addition of AM has a significant effect on the thixotropy of silicon carbide slurry. The larger the thixotropy ring integral area of ​​the slurry, the better the thixotropy. Studies have shown that the slurry with 1.0% to 2.0% AM added has the largest thixotropy ring integral area, indicating that the thixotropy of the slurry within this content range is the best.

[0019] The reason why the content of carboxymethyl cellulose (CMC) is controlled between 0.1% and 0.4% in the present invention is mainly because the introduction of CMC does not change the rheological properties of silicon carbide slurry. Its shear stress still rises rapidly with the increase of shear rate and then tends to be stable. With the increase of CMC content, the thixotropic property of silicon carbide slurry is enhanced, and the best thixotropic property is exhibited when the CMC addition amount is 0.1% to 0.4%.

[0020] The present invention controls the ratio of experimental raw materials to be 75.0-85.0% silicon carbide (SiC), α-alumina (α-Al 2 O 3 ): 13.0~14.5%, silicon dioxide (SiO 2 ): 5.5-6.0%, mainly because the silicon carbide slurry prepared within this ratio range exhibits excellent thixotropy, fluidity and suitable viscosity. In addition, under high temperature conditions, the full reaction of silicon micropowder and alumina can form a mullite phase, thereby improving the high temperature performance of the material. If this ratio is exceeded, the slurry hanging effect on the polyurethane foam will decrease, and the formed mullite phase will not be sufficient.

[0021] The reason why the extrusion height of the pressing roller is controlled within 15-20% of the thickness of the polyurethane foam in the present invention is mainly because when the extrusion height exceeds this range, the amount of slurry hanging on the polyurethane foam will be significantly reduced, resulting in thinner tendons and bones, insufficient ceramic volume proportion in the composite material, and the expected effect cannot be achieved; and when the extrusion height is lower than this range, it is easy to cause pore blockage, so that the melt cannot be smoothly filled during the casting process.

[0022] The reason why the present invention performs secondary high-pressure spraying treatment on the 3D-N SiC preform is mainly because the sample prepared by the primary slurry coating has a small amount of slurry coating, and the tendons are thin and sharp. Through the secondary high-pressure spraying treatment, the coating amount of silicon carbide can be increased, the tendons are thicker, and the sharp hole-rib structure is passivated, so that the tendons are more rounded and smooth. In addition, the blocked holes can be reopened to ensure that the preform has a high porosity.

[0023] The reason why the present invention sets the heating program as follows: heating from room temperature to 600°C at 1-2°C / min, and keeping the temperature for 80-100min; heating from 600°C to 800°C at 2-4°C / min, and keeping the temperature for 0.5-1.5h; heating from 800°C to 1450°C at 5-8°C / min, and cooling with the furnace after keeping the temperature for 2-4h, is mainly to divide the sintering process into three key stages: the heating speed of the first stage (room temperature to 600°C) is as slow as possible to prevent cracking or collapse during the debinding and drying processes; the heating speed of the second stage (600°C to 800°C) is slightly faster than that of the first stage to ensure that the polyurethane foam is fully decomposed and to avoid the incompletely decomposed foam remaining inside the 3D-N SiC preform, thereby affecting the mechanical properties of the silicon carbide ceramic; the heating speed of the third stage (800°C to 1450°C) is faster than that of the first two stages, and the holding time is extended at the same time to promote the full conversion of the glass phase into mullite at high temperature.

[0024] The reason why the present invention performs vacuum impregnation treatment on the 3D-N SiC preform is mainly because the polyurethane foam will completely decompose during the high-temperature sintering process, resulting in the formation of triangular hole defects on the silicon carbide skeleton, so that the inside of the silicon carbide pore ribs presents a hollow structure. In addition, the ceramic surface is easily oxidized at high temperatures to generate weak phase cristobalite. These factors seriously affect the mechanical properties of the 3D-N SiC preform. The vacuum impregnation method can repair the defects on the surface of the silicon carbide pore ribs and fill the hollow structure and triangular holes, thereby enhancing the comprehensive mechanical properties of the 3D-N SiC preform, and finally obtaining a 3D-NSiC / Cu-based composite material with excellent comprehensive mechanical properties.

[0025] The reason why the present invention chooses to vacuum impregnate alumina slurry containing andalusite instead of silicon carbide slurry with higher hardness and the same as the SiC skeleton preform is mainly because silicon carbide slurry is a typical pseudoplastic fluid with poor fluidity, making it difficult to fill the tiny triangular holes in the tendons and bones, and it is not easy to slurry on the surface of SiC tendons. Although the hardness of alumina is slightly lower than that of silicon carbide, alumina slurry is easier to fill the triangular holes in the silicon carbide tendons and can better slurry on the surface of the SiC skeleton. Therefore, it is the best choice to choose alumina, which has a hardness close to that of the SiC skeleton and is a Newtonian fluid, as the raw material for vacuum impregnation.

[0026] The reason why the present invention chooses to add andalusite to the vacuum impregnation alumina slurry is mainly because although the 3D-N SiC ceramics after vacuum impregnation of alumina slurry will form a three-layer structure pore rib (mullite coating, mullite-bonded silicon carbide skeleton layer and alumina filling layer), due to the different properties of the materials of each layer, the difference between the linear expansion coefficients will inevitably cause residual stress inside the ribs, thereby affecting the comprehensive mechanical properties of the material. By introducing a certain solid content of andalusite into the vacuum impregnation alumina slurry, the composition of the slurry can be adjusted, thereby controlling the linear expansion coefficient of the three-layer structure pore ribs and reducing the generation of internal residual stress. This will help to enhance the toughening effect of 3D-N SiC ceramics and further strengthen their comprehensive mechanical properties.

[0027] The ratio of the alumina slurry containing andalusite for vacuum impregnation in the present invention is controlled as follows: α-alumina (α-Al 2 O 3 ): 75.5~80.0%, andalusite (Al 2 SiO 5 ): 20.0~25.0%, mainly because good filling performance can be maintained within this ratio range. This can not only effectively fill the hollow pores, but also densify the SiC skeleton. If it exceeds this ratio range, the viscosity of the slurry may be too large, resulting in the inability to effectively fill the pores, thereby affecting the overall performance of the material; if it is lower than this ratio range, the fluidity and filling capacity of the slurry will decrease, and the structure of the SiC skeleton cannot be fully covered and filled, which may lead to the formation of defects, thereby affecting the mechanical properties and stability of the final product.

[0028] The reason why the present invention should set a draft angle of 1 to 3° in the riser and the cavity is mainly because too large a draft angle will reduce the accuracy of the casting and increase the wear of the mold; while too low a draft angle may cause difficulty in demolding, even damage the casting, and increase defects such as scratches or damage on the casting surface.

[0029] The reason why the present invention is mixed according to the ratio of resin sand: resin: curing agent = 90-100: 1-1.2: 0.3-0.6 is mainly to ensure that the strength of the casting is ensured while ensuring good fluidity and curing performance. If the ratio is exceeded, it may cause the casting to be difficult to demold, surface defects, or insufficient operation time, making it difficult for the casting to form a uniform structure, thereby reducing the surface quality; and if the ratio is lower than the ratio, the casting strength will be insufficient, and it will be easy to deform or collapse during the casting process, affecting the quality of the casting. In addition, incomplete curing will prolong the curing time, reduce production efficiency, and may cause surface defects or insufficient strength of the casting.

[0030] The reason why the gate size at the bottom of the upper mold is smaller than the cavity size is mainly because the density of ceramic is much smaller than that of metal copper, which can easily cause the ceramic to float during the pouring process. The gate size at the bottom of the upper mold is smaller than the cavity size, which can fix the ceramic and avoid the phenomenon of floating of the workpiece.

[0031] Compared with the prior art, the present invention provides a method for preparing a three-dimensional mesh structure SiC / Cu-based composite material for improving the wear resistance of blast furnace tuyere. The method has a simple process and moderate cost, and can significantly improve the wear resistance of the tuyere while ensuring high thermal conductivity and heat dissipation capacity, thereby extending its service life and reducing maintenance costs. Compared with the copper material commonly used by large domestic steel companies, the composite material prepared by this technology has excellent erosion resistance, thermal shock resistance, high temperature resistance and slag iron erosion resistance, and its wear resistance can reach 9.2 to 10.5 times that of copper materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of the three-dimensional structure of the new type blast furnace tuyere inner liner of the present invention;

[0033] Figure 2 for Figure 1 A schematic diagram of a two-dimensional cross-sectional structure of the inner sleeve shown;

[0034] Figure 3 A macroscopic structure diagram of a three-dimensional network structure SiC ceramic prepared in an embodiment of the present invention;

[0035] Figure 4 This is a macroscopic structure diagram of the three-dimensional network structure SiC / Cu-based composite material prepared in an embodiment of the present invention. DETAILED DESCRIPTION

[0036] A method for preparing a three-dimensional network structure SiC / Cu-based composite material for improving the wear resistance of a blast furnace tuyere, comprising the following steps:

[0037] Example 1

[0038] 1) Preparation of SiC slurry: First, the raw materials required for the experiment were weighed in proportion and poured into a stirrer for premixing. Next, the additives were weighed and completely dissolved in deionized water, and the deionized water containing the additives was added dropwise to the premixed raw materials, and the slurry was stirred continuously until the slurry was uniform, thereby obtaining a silicon carbide slurry with excellent thixotropy, fluidity and viscosity.

[0039] 2) Preparation of three-dimensional network structure SiC blank: The cut polyurethane foam is fully immersed in silicon carbide slurry, and then placed on a roller press to squeeze out excess slurry. To ensure the through-porosity of the 3D-N SiC preform, the extrusion height of the press roller is set to 15% of the thickness of the polyurethane foam. Subsequently, an air compressor is used to blow open the blocked pores and distribute the slurry as evenly as possible on the three-dimensional network polyurethane skeleton, thereby obtaining a high-porosity 3D-N SiC blank;

[0040] 3) Preparation of 3D-N SiC preform by secondary high-pressure spraying of silicon carbide slurry: The secondary spraying uses silicon carbide slurry with the same formula as the primary slurry and mixes it evenly in a cement mixer. The difference is that a small amount of deionized water needs to be added to the slurry for the secondary spraying to ensure that the slurry can be sprayed evenly in the high-pressure spray pot. After the secondary high-pressure spraying slurry is prepared, it is loaded into a high-pressure spray pot and sprayed on the sample after the primary slurry treatment, trying to make the slurry evenly cover the silicon carbide skeleton, and reopen the blocked holes through high-pressure treatment to ensure that the preform has a high porosity. After spraying, the blank is naturally air-dried for 18 hours, and then placed in a drying oven at 100°C for 10 hours. The dried green blank was placed in a T-1700 high-temperature sintering furnace for sintering, and the heating program was as follows: heating from room temperature to 600°C at 1°C / min, and keeping warm for 80 minutes; heating from 600°C to 800°C at 2°C / min, and keeping warm for 0.5 hours; heating from 800°C to 1450°C at 5°C / min, keeping warm for 2 hours, and then cooling with the furnace, and finally the 3D-N SiC preform SI1 was obtained;

[0041] 4) Preparation of vacuum impregnation reinforced 3D-N SiC preform: Weigh the alumina slurry containing andalusite in proportion and pour it into a corundum tank, and add an appropriate amount of deionized water for premixing. Then ball mill it on a ball mill at a speed of 250 rpm for 2 hours to obtain the alumina slurry containing andalusite for vacuum impregnation. The 3D-N SiC preform is completely immersed in the vacuum impregnation slurry, and placed in a vacuum box together, evacuated to a vacuum state of 0.5 Pa and maintained for 25 minutes. After taking out the sample, let it air dry naturally and dry it at 100°C. Subsequently, the sample is placed in a high-temperature sintering furnace, sintered at 1400°C, cooled to room temperature with the furnace and taken out, and the sample is named SI2;

[0042] 5) Design and preparation of resin sand mold: Sand casting is divided into an upper mold and a lower mold, in which the upper mold is provided with a pouring riser, which will be cut off after the sample is formed. The lower mold is provided with a cavity that matches the size of the 3D-N SiC ceramic, which is convenient for the metal liquid to fill and form the metal matrix composite material. It is particularly important to note that a draft angle of 1° should be set in the riser and the cavity. The resin sand mold uses 40-mesh resin sand as the molding material, and resin and curing agent as additives, and the ratio is resin sand: resin: curing agent = 90:1:0.3. The specific process is: first, mix the resin sand and curing agent for 3 minutes, and after mixing evenly, add the resin and stir quickly. Subsequently, pour the mixture into the mold, and the resin and curing agent react to cause the sand mold to harden and form the mold;

[0043] 6) Preparation of 3D-N SiC / Cu-based composite materials by sand casting: The 3D-N SiC preform SI2 is placed in the lower mold, and then the upper mold is closed, and the design method is adopted that the size of the gate channel at the bottom of the upper mold is smaller than the size of the cavity. Subsequently, the matrix material T2 pure copper is heated to 1135°C in a crucible resistance furnace, and after it is completely melted, it is poured into a resin sand casting mold containing SI2, and taken out after cooling to room temperature. The SiC / Cu-based composite material prepared by the preform is named SI22. The 3D-N SiC preform SI2 is placed in the lower mold, and then the upper mold is closed, and the design method is adopted that the size of the gate channel at the bottom of the upper mold is smaller than the size of the cavity. Next, the T2 pure copper matrix material is heated to 1135°C in a crucible resistance furnace, and after it is completely melted, it is quickly poured into a resin sand mold containing SI2. After cooling to room temperature, the sample is taken out, and the obtained SiC / Cu-based composite material is named SI22.

[0044] The experimental raw material composition and weight percentage content in the SiC slurry are: silicon carbide (SiC): 81.5%, α-alumina (α-Al 2 O 3 ): 13.0%, silicon dioxide (SiO 2 ): 5.5%; the additive composition and weight percentage content are: carboxymethyl cellulose (CMC): 0.1%, ammonium lignin sulfonate (AM): 1.0%, polycarboxylate (FS65): 0.1%, and the rest is water. In addition, CMC is a thickener, AM is a binder, and FS65 is a dispersant.

[0045] The vacuum impregnation of alumina slurry containing andalusite has the following composition and weight percentage: α-alumina (α-Al 2 O 3 ): 75.5%, andalusite (Al 2 SiO 5 ): 24.5%; the composition and weight percentage of the additives are: polycarboxylate (FS65): 0.1%, and the rest is water.

[0046] Example 2

[0047] 1) Preparation of SiC slurry: First, the raw materials required for the experiment were weighed in proportion and poured into a stirrer for premixing. Next, the additives were weighed and completely dissolved in deionized water, and the deionized water containing the additives was added dropwise to the premixed raw materials, and the slurry was stirred continuously until the slurry was uniform, thereby obtaining a silicon carbide slurry with excellent thixotropy, fluidity and viscosity.

[0048] 2) Preparation of three-dimensional network structure SiC blank: The cut polyurethane foam is fully immersed in silicon carbide slurry, and then placed on a roller press to squeeze out excess slurry. To ensure the through-porosity of the 3D-N SiC preform, the extrusion height of the press roller is set to 16.5% of the thickness of the polyurethane foam. Subsequently, an air compressor is used to blow open the blocked pores and distribute the slurry as evenly as possible on the three-dimensional network polyurethane skeleton, thereby obtaining a high-porosity 3D-N SiC blank;

[0049] 3) Preparation of 3D-N SiC preform by secondary high-pressure spraying of silicon carbide slurry: The secondary spraying uses silicon carbide slurry with the same formula as the primary slurry and mixes it evenly in a cement mixer. The difference is that a small amount of deionized water needs to be added to the slurry for the secondary spraying to ensure that the slurry can be sprayed evenly in the high-pressure spray pot. After the secondary high-pressure spraying slurry is prepared, it is loaded into a high-pressure spray pot and sprayed on the sample after the primary slurry treatment, trying to make the slurry evenly cover the silicon carbide skeleton, and reopen the blocked holes through high-pressure treatment to ensure that the preform has a high porosity. After spraying, the blank is naturally air-dried for 19 hours and then placed in a drying oven at 105°C for 10 hours. The dried green blank was placed in a T-1700 high-temperature sintering furnace for sintering, and the heating program was as follows: heating from room temperature to 600°C at 1.5°C / min, and keeping warm for 80-100min; heating from 600°C to 800°C at 2.5°C / min, and keeping warm for 1h; heating from 800°C to 1450°C at 6°C / min, keeping warm for 2.5h, and then cooling with the furnace, and finally obtaining the 3D-N SiC preform SI1;

[0050] 4) Preparation of vacuum impregnation reinforced 3D-N SiC preform: Weigh the alumina slurry containing andalusite in proportion and pour it into a corundum tank, and add an appropriate amount of deionized water for premixing. Then ball mill it on a ball mill at a speed of 260 rpm for 2.5 hours to obtain the alumina slurry containing andalusite for vacuum impregnation. The 3D-N SiC preform is completely immersed in the vacuum impregnation slurry, and placed in a vacuum box together, evacuated to a vacuum state of 0.5 Pa and maintained at a pressure of 27 minutes. After taking out the sample, let it air dry naturally and dry it at 110°C. Subsequently, the sample is placed in a high-temperature sintering furnace, sintered at 1410°C, cooled to room temperature with the furnace and taken out, and the sample is named SI2;

[0051] 5) Design and preparation of resin sand mold: Sand casting is divided into an upper mold and a lower mold, in which the upper mold is provided with a pouring riser, which will be cut off after the sample is formed. The lower mold is provided with a cavity that matches the size of the 3D-N SiC ceramic, which is convenient for the metal liquid to fill and form the metal matrix composite material. It is particularly important to note that a draft angle of 1° should be set in the riser and the cavity. The resin sand mold uses 50-mesh resin sand as the molding material, and resin and curing agent as additives, and the ratio is resin sand: resin: curing agent = 95:1:0.4. The specific process is: first, mix the resin sand and curing agent for 3 minutes, and after mixing evenly, add the resin and stir quickly. Subsequently, the mixture is poured into the mold, and the resin and curing agent react, causing the sand mold to harden and form the mold;

[0052] 6) Preparation of 3D-N SiC / Cu-based composite materials by sand casting: The 3D-N SiC preform SI2 is placed in the lower mold, and then the upper mold is closed, and the design method is adopted that the size of the gate channel at the bottom of the upper mold is smaller than the size of the cavity. Subsequently, the matrix material T2 pure copper is heated to 1150°C in a crucible resistance furnace, and after it is completely melted, it is poured into a resin sand casting mold containing SI2, and taken out after cooling to room temperature. The SiC / Cu-based composite material prepared by the preform is named SI22. The 3D-N SiC preform SI2 is placed in the lower mold, and then the upper mold is closed, and the design method is adopted that the size of the gate channel at the bottom of the upper mold is smaller than the size of the cavity. Next, the T2 pure copper matrix material is heated to 1150°C in a crucible resistance furnace, and after it is completely melted, it is quickly poured into a resin sand mold containing SI2. After cooling to room temperature, the sample is taken out, and the obtained SiC / Cu-based composite material is named SI22.

[0053] The experimental raw material composition and weight percentage content in the SiC slurry are: silicon carbide (SiC): 80.5%, α-alumina (α-Al 2 O 3 ): 13.7%, silicon dioxide (SiO 2): 5.8%; the additive composition and weight percentage content are: carboxymethyl cellulose (CMC): 0.2%, ammonium lignin sulfonate (AM): 1.5%, polycarboxylate (FS65): 0.15%, and the rest is water. In addition, CMC is a thickener, AM is a binder, and FS65 is a dispersant.

[0054] The vacuum impregnation of alumina slurry containing andalusite has the following composition and weight percentage: α-alumina (α-Al 2 O 3 ): 78.5%, andalusite (Al 2 SiO 5 ): 21.5%; the composition and weight percentage of the additives are: polycarboxylate (FS65): 0.15%, and the rest is water.

[0055] Example 3

[0056] 1) Preparation of SiC slurry: First, the raw materials required for the experiment were weighed in proportion and poured into a stirrer for premixing. Next, the additives were weighed and completely dissolved in deionized water, and the deionized water containing the additives was added dropwise to the premixed raw materials, and the slurry was stirred continuously until the slurry was uniform, thereby obtaining a silicon carbide slurry with excellent thixotropy, fluidity and viscosity.

[0057] 2) Preparation of three-dimensional network structure SiC blank: The cut polyurethane foam is fully immersed in silicon carbide slurry, and then placed on a roller press to squeeze out excess slurry. To ensure the through-porosity of the 3D-N SiC preform, the extrusion height of the press roller is set to 17% of the thickness of the polyurethane foam. Subsequently, an air compressor is used to blow open the blocked pores and distribute the slurry as evenly as possible on the three-dimensional network polyurethane skeleton, thereby obtaining a high-porosity 3D-N SiC blank;

[0058] 3) Preparation of 3D-N SiC preform by secondary high-pressure spraying of silicon carbide slurry: The secondary spraying uses silicon carbide slurry with the same formula as the primary slurry and mixes it evenly in a cement mixer. The difference is that a small amount of deionized water needs to be added to the slurry for the secondary spraying to ensure that the slurry can be sprayed evenly in the high-pressure spray pot. After the secondary high-pressure spraying slurry is prepared, it is loaded into a high-pressure spray pot and sprayed on the sample after the primary slurry treatment, trying to make the slurry evenly cover the silicon carbide skeleton, and reopen the blocked holes through high-pressure treatment to ensure that the preform has a high porosity. After spraying, the blank is naturally air-dried for 20 hours, and then placed in a drying oven at 110°C for 12 hours. The dried green blank was placed in a T-1700 high-temperature sintering furnace for sintering, and the heating program was as follows: heating from room temperature to 600°C at 1.5°C / min, and keeping warm for 80-100min; heating from 600°C to 800°C at 3°C / min, and keeping warm for 1h; heating from 800°C to 1450°C at 7°C / min, keeping warm for 3h, and then cooling with the furnace, and finally obtaining the 3D-N SiC preform SI1;

[0059] 4) Preparation of vacuum impregnation reinforced 3D-N SiC preform: Weigh the alumina slurry containing andalusite in proportion and pour it into a corundum tank, and add an appropriate amount of deionized water for premixing. Then ball mill it on a ball mill at a speed of 250 rpm for 3 hours to obtain the alumina slurry containing andalusite for vacuum impregnation. The 3D-N SiC preform is completely immersed in the vacuum impregnation slurry, and placed in a vacuum box together, evacuated to a vacuum state of 0.7 Pa and maintained at a pressure of 28 minutes. After taking out the sample, let it air dry naturally and dry it at 110°C. Subsequently, the sample is placed in a high-temperature sintering furnace, sintered at 1430°C, cooled to room temperature with the furnace and taken out, and the sample is named SI2;

[0060] 5) Design and preparation of resin sand mold: Sand casting is divided into an upper mold and a lower mold, in which the upper mold is provided with a pouring riser, which will be cut off after the sample is formed. The lower mold is provided with a cavity that matches the size of the 3D-N SiC ceramic, which is convenient for the metal liquid to fill and form the metal matrix composite material. It is particularly important to note that a draft angle of 2° should be set in the riser and the cavity. The resin sand mold uses 50-mesh resin sand as the molding material, and resin and curing agent as additives, and the ratio is resin sand: resin: curing agent = 95:1:0.5. The specific process is: first, mix the resin sand and curing agent for 4 minutes, and after mixing evenly, add the resin and stir quickly. Subsequently, pour the mixture into the mold, and the resin and curing agent react to cause the sand mold to harden and form the mold;

[0061] 6) Preparation of 3D-N SiC / Cu-based composite materials by sand casting: The 3D-N SiC preform SI2 is placed in the lower mold, and then the upper mold is closed, and the design method is adopted that the size of the gate channel at the bottom of the upper mold is smaller than the size of the cavity. Subsequently, the matrix material T2 pure copper is heated to 1180°C in a crucible resistance furnace, and after it is completely melted, it is poured into a resin sand casting mold containing SI2, and taken out after cooling to room temperature. The SiC / Cu-based composite material prepared by the preform is named SI22. The 3D-N SiC preform SI2 is placed in the lower mold, and then the upper mold is closed, and the design method is adopted that the size of the gate channel at the bottom of the upper mold is smaller than the size of the cavity. Next, the T2 pure copper matrix material is heated to 1180°C in a crucible resistance furnace, and after it is completely melted, it is quickly poured into a resin sand mold containing SI2. After cooling to room temperature, the sample is taken out, and the obtained SiC / Cu-based composite material is named SI22.

[0062] The experimental raw material composition and weight percentage content in the SiC slurry are: silicon carbide (SiC): 80.4%, α-alumina (α-Al 2 O 3 ): 13.8%, silicon dioxide (SiO 2 ): 5.8%; the additive composition and weight percentage content are: carboxymethyl cellulose (CMC): 0.3%, ammonium lignin sulfonate (AM): 1.5%, polycarboxylate (FS65): 0.2%, and the rest is water. In addition, CMC is a thickener, AM is a binder, and FS65 is a dispersant.

[0063] The vacuum impregnation of alumina slurry containing andalusite has the following composition and weight percentage: α-alumina (α-Al 2 O 3 ): 78.5%, andalusite (Al 2 SiO 5 ): 21.5%; the composition and weight percentage of the additives are: polycarboxylate (FS65): 0.2%, and the rest is water.

[0064] Example 4

[0065] 1) Preparation of SiC slurry: First, the raw materials required for the experiment were weighed in proportion and poured into a stirrer for premixing. Next, the additives were weighed and completely dissolved in deionized water, and the deionized water containing the additives was added dropwise to the premixed raw materials, and the slurry was stirred continuously until the slurry was uniform, thereby obtaining a silicon carbide slurry with excellent thixotropy, fluidity and viscosity.

[0066] 2) Preparation of three-dimensional network structure SiC blank: The cut polyurethane foam is fully immersed in silicon carbide slurry, and then placed on a roller press to squeeze out excess slurry. To ensure the through-porosity of the 3D-N SiC preform, the extrusion height of the press roller is set to 18% of the thickness of the polyurethane foam. Subsequently, an air compressor is used to blow open the blocked pores and distribute the slurry as evenly as possible on the three-dimensional network polyurethane skeleton, thereby obtaining a high-porosity 3D-N SiC blank;

[0067] 3) Preparation of 3D-N SiC preform by secondary high-pressure spraying of silicon carbide slurry: The secondary spraying uses silicon carbide slurry with the same formula as the primary slurry and mixes it evenly in a cement mixer. The difference is that a small amount of deionized water needs to be added to the slurry for the secondary spraying to ensure that the slurry can be sprayed evenly in the high-pressure spray pot. After the secondary high-pressure spraying slurry is prepared, it is loaded into a high-pressure spray pot and sprayed on the sample after the primary slurry treatment, trying to make the slurry evenly cover the silicon carbide skeleton, and reopen the blocked holes through high-pressure treatment to ensure that the preform has a high porosity. After spraying, the blank is naturally air-dried for 20 hours, and then placed in a drying oven at 115°C for 13 hours. The dried green blank was placed in a T-1700 high-temperature sintering furnace for sintering, and the heating program was as follows: heating from room temperature to 600°C at 1°C / min, and keeping warm for 90 minutes; heating from 600°C to 800°C at 2°C / min, and keeping warm for 0.5 hours; heating from 800°C to 1450°C at 7°C / min, keeping warm for 3 hours, and then cooling with the furnace, and finally the 3D-N SiC preform SI1 was obtained;

[0068] 4) Preparation of vacuum impregnation reinforced 3D-N SiC preform: Weigh the alumina slurry containing andalusite in proportion and pour it into a corundum tank, and add an appropriate amount of deionized water for premixing. Then ball mill it on a ball mill at a speed of 250 rpm for 3 hours to obtain the alumina slurry containing andalusite for vacuum impregnation. The 3D-N SiC preform is completely immersed in the vacuum impregnation slurry, and placed in a vacuum box together, evacuated to a vacuum state of 0.5 Pa and maintained for 25 minutes. After taking out the sample, let it air dry naturally and dry it at 110°C. Subsequently, the sample is placed in a high-temperature sintering furnace, sintered at 1400°C, cooled to room temperature with the furnace and taken out, and the sample is named SI2;

[0069] 5) Design and preparation of resin sand mold: Sand casting is divided into an upper mold and a lower mold, in which the upper mold is provided with a pouring riser, which will be cut off after the sample is formed. The lower mold is provided with a cavity that matches the size of the 3D-N SiC ceramic, which is convenient for the metal liquid to fill and form the metal matrix composite material. It is particularly important to note that a draft angle of 1.5° should be set in the riser and the cavity. The resin sand mold uses 60-mesh resin sand as the molding material, and resin and curing agent as additives, and the ratio is resin sand: resin: curing agent = 95:1.1:0.5. The specific process is: first, mix the resin sand and curing agent for 3 minutes, and after the mixture is evenly mixed, add the resin and stir quickly. Subsequently, the mixture is poured into the mold, and the resin and curing agent react to cause the sand mold to harden and form the mold;

[0070] 6) Preparation of 3D-N SiC / Cu-based composite materials by sand casting: The 3D-N SiC preform SI2 is placed in the lower mold, and then the upper mold is closed, and the design method is adopted that the size of the gate channel at the bottom of the upper mold is smaller than the size of the cavity. Subsequently, the matrix material T2 pure copper is heated to 1190°C in a crucible resistance furnace, and after it is completely melted, it is poured into a resin sand casting mold containing SI2, and taken out after cooling to room temperature. The SiC / Cu-based composite material prepared by the preform is named SI22. The 3D-N SiC preform SI2 is placed in the lower mold, and then the upper mold is closed, and the design method is adopted that the size of the gate channel at the bottom of the upper mold is smaller than the size of the cavity. Next, the T2 pure copper matrix material is heated to 1190°C in a crucible resistance furnace, and after it is completely melted, it is quickly poured into a resin sand mold containing SI2. After cooling to room temperature, the sample is taken out, and the obtained SiC / Cu-based composite material is named SI22.

[0071] The experimental raw material composition and weight percentage content in the SiC slurry are: silicon carbide (SiC): 80.0%, α-alumina (α-Al 2 O 3 ): 14.0%, silicon dioxide (SiO 2 ): 6.0%; the additive composition and weight percentage content are: carboxymethyl cellulose (CMC): 0.3%, ammonium lignin sulfonate (AM): 1.5%, polycarboxylate (FS65): 0.3%, and the rest is water. In addition, CMC is a thickener, AM is a binder, and FS65 is a dispersant.

[0072] The vacuum impregnation of alumina slurry containing andalusite has the following composition and weight percentage: α-alumina (α-Al 2 O 3 ): 80.0%, andalusite (Al 2 SiO 5): 20.0%; the composition and weight percentage of the additives are: polycarboxylate (FS65): 0.3%, and the rest is water.

[0073] Example 5

[0074] 1) Preparation of SiC slurry: First, the raw materials required for the experiment were weighed in proportion and poured into a stirrer for premixing. Next, the additives were weighed and completely dissolved in deionized water, and the deionized water containing the additives was added dropwise to the premixed raw materials, and the slurry was stirred continuously until the slurry was uniform, thereby obtaining a silicon carbide slurry with excellent thixotropy, fluidity and viscosity.

[0075] 2) Preparation of three-dimensional network structure SiC blank: The cut polyurethane foam is fully immersed in silicon carbide slurry, and then placed on a roller press to squeeze out excess slurry. To ensure the through-porosity of the 3D-N SiC preform, the extrusion height of the press roller is set to 20% of the thickness of the polyurethane foam. Subsequently, an air compressor is used to blow open the blocked pores and distribute the slurry as evenly as possible on the three-dimensional network polyurethane skeleton, thereby obtaining a high-porosity 3D-N SiC blank;

[0076] 3) Preparation of 3D-N SiC preform by secondary high-pressure spraying of silicon carbide slurry: The secondary spraying uses silicon carbide slurry with the same formula as the primary slurry and mixes it evenly in a cement mixer. The difference is that a small amount of deionized water needs to be added to the slurry for the secondary spraying to ensure that the slurry can be sprayed evenly in the high-pressure spray pot. After the secondary high-pressure spraying slurry is prepared, it is loaded into a high-pressure spray pot and sprayed on the sample after the primary slurry treatment, trying to make the slurry evenly cover the silicon carbide skeleton, and reopen the blocked holes through high-pressure treatment to ensure that the preform has a high porosity. After spraying, the blank is naturally air-dried for 24 hours, and then placed in a drying oven at 115°C for 14 hours. The dried green blank was placed in a T-1700 high-temperature sintering furnace for sintering, and the heating program was as follows: heating from room temperature to 600°C at 2°C / min, and keeping warm for 100 minutes; heating from 600°C to 800°C at 4°C / min, and keeping warm for 1.5 hours; heating from 800°C to 1450°C at 8°C / min, keeping warm for 4 hours, and then cooling with the furnace, and finally obtaining the 3D-N SiC preform SI1;

[0077] 4) Preparation of vacuum impregnation reinforced 3D-N SiC preform: Weigh the alumina slurry containing andalusite in proportion and pour it into a corundum tank, and add an appropriate amount of deionized water for premixing. Then ball mill it on a ball mill at a speed of 300 rpm for 4 hours to obtain the alumina slurry containing andalusite for vacuum impregnation. The 3D-N SiC preform is completely immersed in the vacuum impregnation slurry, and placed in a vacuum box together, evacuated to a vacuum state of 1 Pa and maintained at a pressure of 30 minutes. After taking out the sample, let it air dry naturally and dry it at 115°C. Subsequently, the sample is placed in a high-temperature sintering furnace, sintered at 1450°C, cooled to room temperature with the furnace and taken out, and the sample is named SI2;

[0078] 5) Design and preparation of resin sand mold: Sand casting is divided into an upper mold and a lower mold, in which the upper mold is provided with a pouring riser, which will be cut off after the sample is formed. The lower mold is provided with a cavity that matches the size of the 3D-N SiC ceramic, which is convenient for the metal liquid to fill and form the metal matrix composite material. It is particularly important to note that a draft angle of 3° should be set in the riser and the cavity. The resin sand mold uses 70 mesh resin sand as the molding material, and resin and curing agent as additives, and the ratio is resin sand: resin: curing agent = 100: 1.2: 0.6. The specific process is: first, mix the resin sand and curing agent for 5 minutes, and after mixing evenly, add the resin and stir quickly. Subsequently, the mixture is poured into the mold, and the resin and curing agent react, causing the sand mold to harden and form the mold;

[0079] 6) Preparation of 3D-N SiC / Cu-based composite materials by sand casting: The 3D-N SiC preform SI2 is placed in the lower mold, and then the upper mold is closed, and the design method is adopted that the size of the gate channel at the bottom of the upper mold is smaller than the size of the cavity. Subsequently, the matrix material T2 pure copper is heated to 1200°C in a crucible resistance furnace, and after it is completely melted, it is poured into a resin sand casting mold containing SI2, and taken out after cooling to room temperature. The SiC / Cu-based composite material prepared by the preform is named SI22. The 3D-N SiC preform SI2 is placed in the lower mold, and then the upper mold is closed, and the design method is adopted that the size of the gate channel at the bottom of the upper mold is smaller than the size of the cavity. Next, the T2 pure copper matrix material is heated to 1200°C in a crucible resistance furnace, and after it is completely melted, it is quickly poured into a resin sand mold containing SI2. After cooling to room temperature, the sample is taken out, and the obtained SiC / Cu-based composite material is named SI22.

[0080] The experimental raw material composition and weight percentage content in the SiC slurry are: silicon carbide (SiC): 79.5%, α-alumina (α-Al 2 O 3 ): 14.5%, silicon dioxide (SiO 2): 6.0%; the additive composition and weight percentage content are: carboxymethyl cellulose (CMC): 0.4%, ammonium lignin sulfonate (AM): 2.0%, polycarboxylate (FS65): 0.3%, and the rest is water. In addition, CMC is a thickener, AM is a binder, and FS65 is a dispersant.

[0081] The vacuum impregnation of alumina slurry containing andalusite has the following composition and weight percentage: α-alumina (α-Al 2 O 3 ): 80.0%, andalusite (Al 2 SiO 5 ): 20.0%; the composition and weight percentage of the additives are: polycarboxylate (FS65): 0.3%, and the rest is water.

[0082] This specific implementation is only the best example and is not a restrictive implementation of the technical solution of the present invention.

Claims

1. A method for preparing a three-dimensional mesh structure SiC / Cu-based composite material for improving the wear resistance of blast furnace tuyere. Through the design of the inner lining of the blast furnace tuyere, it can not only effectively protect the tuyere, but also significantly improve its wear resistance while maintaining high thermal conductivity, thereby greatly improving the wear resistance and service life of the tuyere.

2. A method for preparing a three-dimensional network structure SiC / Cu-based composite material for improving the wear resistance of a blast furnace tuyere as claimed in claim 1, comprising the steps of: 1) Preparation of SiC slurry: First, the raw materials required for the experiment were weighed in proportion and poured into a stirrer for premixing. Next, the additives were weighed and completely dissolved in deionized water, and the deionized water containing the additives was added dropwise to the premixed raw materials, and the slurry was stirred continuously until the slurry was uniform, thereby obtaining a silicon carbide slurry with excellent thixotropy, fluidity and viscosity. 2) Preparation of three-dimensional network structure SiC blank: The cut polyurethane foam is fully immersed in silicon carbide slurry, and then placed on a roller press to squeeze out excess slurry. To ensure the porosity of the 3D-N SiC preform, the extrusion height of the press roller is set to 15-20% of the thickness of the polyurethane foam. Subsequently, an air compressor is used to blow open the blocked pores and distribute the slurry as evenly as possible on the three-dimensional network polyurethane skeleton, thereby obtaining a high-porosity 3D-N SiC blank; 3) Preparation of 3D-N SiC preform by secondary high-pressure spraying of silicon carbide slurry: The secondary spraying uses silicon carbide slurry with the same formula as the primary slurry and mixes it evenly in a cement mixer. The difference is that a small amount of deionized water needs to be added to the slurry for the secondary spraying to ensure that the slurry can be sprayed evenly in the high-pressure spray pot. After the secondary high-pressure spraying slurry is prepared, it is loaded into a high-pressure spray pot and sprayed on the sample after the primary slurry treatment, so that the slurry is evenly covered on the silicon carbide skeleton as much as possible, and the blocked holes are reopened by high-pressure treatment to ensure that the preform has a high porosity. After spraying, the blank is naturally air-dried for 18 to 24 hours, and then placed in a drying oven at 100 to 115°C for 10 to 14 hours. The dried green blank is placed in a T-1700 high-temperature sintering furnace for sintering, and the heating program is as follows: heating from room temperature to 600°C at 1-2°C / min, and keeping warm for 80-100min; heating from 600°C to 800°C at 2-4°C / min, and keeping warm for 0.5-1.5h; heating from 800°C to 1450°C at 5-8°C / min, keeping warm for 2-4h, and then cooling with the furnace, and finally obtaining a 3D-N SiC preform SI1; 4) Preparation of vacuum impregnation reinforced 3D-N SiC preform: Weigh the alumina slurry containing andalusite in proportion and pour it into a corundum tank, and add an appropriate amount of deionized water for premixing. Then ball mill it on a ball mill at a speed of 250-300 rpm for 2-4 hours to obtain an alumina slurry containing andalusite for vacuum impregnation. The 3D-N SiC preform is completely immersed in the vacuum impregnation slurry, and placed in a vacuum box together, evacuated to a vacuum state of 0.5-1 Pa and maintained at a pressure of 25-30 minutes. After taking out the sample, let it air dry naturally and dry it at 100-115°C. Subsequently, the sample is placed in a high-temperature sintering furnace, sintered at 1400-1450°C, cooled to room temperature with the furnace and taken out, and the sample is named SI2; 5) Design and preparation of resin sand mold: Sand casting is divided into an upper mold and a lower mold, in which the upper mold is provided with a pouring riser, which will be cut off after the sample is formed. The lower mold is provided with a cavity that matches the size of the 3D-N SiC ceramic, which is convenient for the metal liquid to fill and form the metal matrix composite material. It is particularly important to note that a draft angle of 1 to 3° should be set in the riser and the cavity. The resin sand mold uses 40 to 70 mesh resin sand as the molding material, and resin and curing agent as additives, and is proportioned according to the ratio of resin sand: resin: curing agent = 90 to 100: 1 to 1.2: 0.3 to 0.

6. The specific process is: first, mix the resin sand and curing agent for 3 to 5 minutes, and after mixing evenly, add the resin and stir quickly. Subsequently, the mixture is poured into the mold, and the resin and curing agent react, causing the sand mold to harden and form the mold; 6) Preparation of 3D-N SiC / Cu-based composite materials by sand casting: The 3D-N SiC preform SI2 is placed in the lower mold, and then the upper mold is closed, and the design method is adopted that the size of the gate channel at the bottom of the upper mold is smaller than the size of the cavity. Subsequently, the matrix material T2 pure copper is heated to 1135-1200°C in a crucible resistance furnace, and after it is completely melted, it is poured into a resin sand casting mold containing SI2, and taken out after cooling to room temperature. The SiC / Cu-based composite material prepared by the preform is named SI22. The 3D-N SiC preform SI2 is placed in the lower mold, and then the upper mold is closed, and the design method is adopted that the size of the gate channel at the bottom of the upper mold is smaller than the size of the cavity. Next, the T2 pure copper matrix material is heated to 1135-1200°C in a crucible resistance furnace, and after it is completely melted, it is quickly poured into a resin sand mold containing SI2. After cooling to room temperature, the sample is taken out, and the obtained SiC / Cu-based composite material is named SI22.

3. A method for preparing a three-dimensional network structure SiC / Cu-based composite material for improving the wear resistance of a blast furnace tuyere according to claim 2, characterized in that: The experimental raw material composition and weight percentage content in SiC slurry are: silicon carbide (SiC): 75.0-85.0%, α-alumina (α-Al2O3): 13.0-14.5%, silicon dioxide (SiO2): 5.5-6.0%; the additive composition and weight percentage content are: carboxymethyl cellulose (CMC): 0.1-0.4%, ammonium lignin sulfonate (AM): 1.0-2.0%, polycarboxylate (FS65): 0.1-0.3%, and the rest is water. In addition, CMC is a thickener, AM is a binder, and FS65 is a dispersant.

4. A method for preparing a three-dimensional network structure SiC / Cu-based composite material for improving the wear resistance of a blast furnace tuyere according to claim 2, characterized in that: The composition and weight percentage content of the vacuum impregnation alumina slurry containing andalusite are: α-alumina (α-Al2O3): 75.5-80.0%, andalusite (Al2SiO5): 20.0-25.0%; the composition and weight percentage content of the additives are: polycarboxylate (FS65): 0.1-0.3%, and the rest is water.

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