High-toughness boron nitride setter plate and preparation method thereof

Abstract

The invention relates to the technical field of boron nitride setter plates, in particular to a high-toughness boron nitride setter plate and a preparation method thereof, and the high-toughness boron nitride setter plate comprises the following raw materials in parts by weight: 100-110 parts of a solvent, 90-110 parts of boron nitride powder, 10-20 parts of an auxiliary material, 2-4 parts of an additive, 2-4 parts of a sintering aid and 4-6 parts of a binder. In the preparation of the auxiliary material, the whiskers are prepared into aerogel in advance, so that the aerogel forms a three-dimensional elastic network, toughening can be realized through pull-out, bridging and crack deflection mechanisms, a secondary enhanced network is formed due to mutual entanglement of the whiskers in a matrix, and the toughness of the material is remarkably improved; the graphene oxide in the additive can be further combined with the auxiliary material to form a multi-dimensional enhanced network, and the graphene oxide can effectively prevent crack propagation and deflection cracks, share loads, maintain the structural stability and hinder grain boundary sliding and dislocation movement, so that the strength performance of the boron nitride setter plate is further improved.

Description

Technical Field

[0001] This invention relates to the field of boron nitride sintering plate technology, specifically to a high-toughness boron nitride sintering plate and its preparation method. Background Technology

[0002] Sintering plates are key auxiliary components used in high-temperature sintering processes to support sintered materials such as electronic ceramic components. They need to have good structural stability and durability at high temperatures. Boron nitride ceramics are widely used in the preparation of high-performance sintering plates due to their excellent high-temperature resistance, thermal shock resistance and chemical stability.

[0003] In existing technologies, it is difficult to achieve close packing of boron nitride powder of a single scale, which leads to uneven density of the green blank and a lack of effective toughening mechanisms to inhibit crack propagation, resulting in insufficient strength properties of boron nitride materials. Therefore, this invention provides a high-toughness boron nitride sintering plate and its preparation method. Summary of the Invention

[0004] The purpose of this invention is to provide a high-toughness boron nitride sintering plate and its preparation method. The high-toughness boron nitride sintering plate prepared by this invention has good strength properties and effectively improves the performance of the high-toughness boron nitride sintering plate.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a high-toughness boron nitride sintering plate, comprising the following raw materials in parts by weight: 100-110 parts solvent, 90-110 parts boron nitride powder, 10-20 parts auxiliary materials, 2-4 parts additives, 2-4 parts sintering aids and 4-6 parts binder; The additive's raw materials include graphene oxide, Tris-HCl buffer solution, dopamine hydrochloride, deionized water, and nickel nitrate solution.

[0006] Preferably, the boron nitride powder is prepared by compounding coarse particles, medium particles and fine particles, with a mass ratio of coarse particles, medium particles and fine particles of 1:0.6-0.8:0.1-0.2. The particle size of the coarse particles is selected to be 11-14 μm, the particle size of the medium particles is selected to be 3-6 μm, and the particle size of the fine particles is selected to be 0.3-0.6 μm.

[0007] Preferably, the auxiliary material is prepared by the following method: deionized water is added to a mixer, the temperature is raised to 90°C, then boric acid and melamine are added sequentially, the temperature is raised to 95°C, and the temperature is maintained for 1-2 hours. After heating is stopped, the mixture is stirred at 200-400 rpm for 20-30 minutes. The resulting product is centrifuged and dried, then sent to a tube furnace. The temperature is raised to 700-720°C at a rate of 3-5°C / min and maintained for 2-3 hours. The resulting product is dispersed in ethanol at a mass ratio of 1:50, and ultrasonically treated at 200-300W for 30-40 minutes. Deionized water of 30-50% of the ethanol mass is added. The resulting product is subjected to solvent exchange with tert-butanol three times, and then freeze-dried at -50°C for 48 hours to obtain the auxiliary material.

[0008] Preferably, the mass ratio of boric acid to melamine is 1:0.8-0.9, and the total mass of boric acid and melamine is 6-8% of the mass of deionized water.

[0009] Preferably, the additive is prepared by the following method: graphene oxide is dispersed in a Tris-HCl buffer solution and ultrasonically dispersed at 300-500W for 1-2 hours to obtain a dispersion. Dopamine hydrochloride is added to the dispersion, and the mixture is stirred at 100-200rpm in a mixer for 6-8 hours to obtain a coarse material. The coarse material is dispersed in deionized water, nickel nitrate solution is added, and the mixture is stirred at 200-400rpm for 3-5 hours. The resulting product is freeze-dried and then fed into a tube furnace and purged with air. A mixed gas was heated at a rate of 2–4 °C / min to 450–550 °C and held for 1–2 h to obtain a preparative material. The preparative material was dispersed in NMP, and hydroxysuccinimide was added. The mixture was reacted at 60–70 °C for 4–5 h. Then, polysiloxane was added and the mixture was reacted at 80–85 °C for 4–6 h. The resulting product was centrifuged to obtain a solid. The solid was washed with ethanol 3–5 times and then treated at 200–250 °C for 1–1.5 h to obtain an additive.

[0010] Preferably, the mass ratio of graphene oxide to Tris-HCl buffer solution is 1:150-200, the pH value of Tris-HCl buffer solution is 8.5, the mass of dopamine hydrochloride is 0.06-0.08% of the mass of dispersion, the mass ratio of coarse material to deionized water is 1:15-20, the mass of nickel nitrate solution is 30-40% of the mass of deionized water, the mass concentration of nickel nitrate solution is 2-5%, the mass ratio of pre-material to NMP is 1:500-600, the mass of hydroxysuccinimide is 30-40% of the mass of pre-material, and the mass of polysiloxane is 10-20% of the mass of pre-material.

[0011] Preferably, the flow rate of the mixed gas is 100-120 sccm, and the mixed gas is prepared by mixing 5% hydrogen and 95% argon.

[0012] Preferably, the solvent is prepared by mixing propyl acetate and isobutanol in a volume ratio of 4:1.

[0013] Preferably, the sintering aid is yttrium oxide, and the binder is a 3% polyvinyl alcohol aqueous solution.

[0014] Preferably, a method for preparing a high-toughness boron nitride sintering plate includes the following steps: solvent, boron nitride powder, auxiliary materials, additives, sintering aids, and binders are weighed as needed and added to a mixer. The mixer is set to 60-100 rpm and stirred for 30-50 minutes to obtain a slurry. The slurry is spray-dried to obtain powder. The powder is sieved through a 100-120 mesh sieve and then placed into a mold. Static pressing is performed under a pressure of 80-90 MPa to obtain a green blank. The green blank is sent to a sintering furnace, and under nitrogen atmosphere protection, the heating rate is set to 5-10℃ / min, and the temperature is raised to 1700-1900℃ while applying a pressure of 200T. The temperature and pressure are maintained for 3-4 hours. After cooling, a substrate is obtained. The substrate is cut, ground, and polished to obtain the high-toughness boron nitride sintering plate.

[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. In the preparation of the auxiliary materials of this invention, the whiskers are pre-prepared into aerogels, forming a three-dimensional elastic network. During the mixing process, the network dissociates to a certain extent but still retains local entanglement, effectively avoiding the whisker agglomeration and orientation problems caused by the traditional direct addition method. After sintering, the "cluster-like" distributed whiskers can be toughened through pull-out, bridging, and crack deflection mechanisms. They also form a secondary reinforcing network in the matrix due to their mutual entanglement, which significantly improves the toughness of the material. The graphene oxide in the additive can be further combined with the auxiliary materials to form a multi-dimensional reinforcing network. Graphene oxide can effectively prevent crack propagation, deflect cracks, and share the load. Polydopamine can form a coating and provide adhesion properties on the surface of graphene oxide. Combined with the addition of nickel nitrate solution, the nickel nanoparticles are firmly anchored to graphene oxide, maintaining the stability of its structure, hindering grain boundary sliding and dislocation movement, and further improving the strength performance of the boron nitride sintering plate.

[0016] 2. In this invention, by using a multi-particle-size ratio of boron nitride powder, the combination of coarse, medium and fine particles can achieve close packing, which improves the density of the green body, reduces sintering shrinkage and internal defects, and lays the foundation for obtaining a highly dense sintered body. Attached Figure Description

[0017] Figure 1The present invention provides a flowchart of a high-toughness boron nitride sintering plate and its preparation method. Detailed Implementation

[0018] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0019] It should be noted that the raw materials used in the following embodiments are all commercially available.

[0020] Example 1: 2:

[0021] A high-toughness boron nitride sintering plate comprises the following raw materials in parts by weight: 100 parts solvent, 90 parts boron nitride powder, 10 parts auxiliary materials, 2 parts additives, 2 parts sintering aids and 4 parts binder; The solvent is prepared by mixing propyl acetate and isobutanol in a volume ratio of 4:1.

[0022] Among them, yttrium oxide is selected as the sintering aid, and 3% polyvinyl alcohol aqueous solution is selected as the binder.

[0023] The additives are made from graphene oxide, Tris-HCl buffer solution, dopamine hydrochloride, deionized water, and nickel nitrate solution.

[0024] The boron nitride powder is prepared by compounding coarse, medium and fine particles, with a mass ratio of 1:0.6:0.1. The particle size of the coarse particles is 11 μm, the particle size of the medium particles is 3 μm, and the particle size of the fine particles is 0.3 μm.

[0025] The auxiliary material was prepared by the following method: Deionized water was added to a mixer and heated to 90°C. Boric acid and melamine were then added sequentially, and the temperature was raised to 95°C and held for 1 hour. Heating was then stopped, and the mixture was stirred at 200 rpm for 20 minutes. The resulting product was centrifuged, dried, and then placed in a tube furnace. The temperature was raised to 700°C at a rate of 3°C / min and held for 2 hours. The resulting product was dispersed in ethanol at a mass ratio of 1:50 and ultrasonically treated at 200W for 30 minutes. Deionized water at 30% of the ethanol mass was added. The resulting product was subjected to solvent exchange with tert-butanol three times, and then freeze-dried at -50°C for 48 hours to obtain the auxiliary material.

[0026] The mass ratio of boric acid to melamine is 1:0.8, and the total mass of boric acid and melamine is 6% of the mass of deionized water.

[0027] The additive was prepared by the following method: graphene oxide was dispersed in Tris-HCl buffer solution and ultrasonically dispersed at 300W for 1 hour to obtain a dispersion. Dopamine hydrochloride was added to the dispersion and stirred at 100 rpm for 6 hours in a mixer to obtain a coarse material. The coarse material was dispersed in deionized water, nickel nitrate solution was added, and stirred at 200 rpm for 3 hours. The resulting product was freeze-dried and then sent to a tube furnace. A mixed gas was introduced, and the temperature was raised to 450℃ at a rate of 2℃ / min and held for 1 hour to obtain a preparative material. The preparative material was dispersed in NMP, hydroxysuccinimide was added, and the reaction was carried out at 60℃ for 4 hours. Then, polysiloxane was added, and the reaction was carried out at 80℃ for 4 hours. The resulting product was centrifuged to obtain a solid. The solid was washed three times with ethanol and then treated at 200℃ for 1 hour to obtain the additive.

[0028] The mass ratio of graphene oxide to Tris-HCl buffer solution was 1:150, the pH value of Tris-HCl buffer solution was 8.5, the mass of dopamine hydrochloride was 0.06% of the mass of dispersion, the mass ratio of coarse material to deionized water was 1:15, the mass of nickel nitrate solution was 30% of the mass of deionized water, the mass concentration of nickel nitrate solution was 2%, the mass ratio of pre-material to NMP was 1:500, the mass of hydroxysuccinimide was 30% of the mass of pre-material, and the mass of polysiloxane was 10% of the mass of pre-material.

[0029] The mixed gas flow rate is 100 sccm, and the mixed gas is prepared by mixing 5% hydrogen and 95% argon.

[0030] A method for preparing a high-toughness boron nitride sintering plate includes the following steps: solvent, boron nitride powder, auxiliary materials, additives, sintering aids, and binders are weighed as needed and added to a mixer. The mixer is set to 60 rpm and stirred for 30 minutes to obtain a slurry. The slurry is spray-dried to obtain powder. The powder is sieved through a 100-mesh sieve and then placed into a mold. The powder is statically pressed under a pressure of 80 MPa to obtain a green blank. The green blank is then placed in a sintering furnace. Under a nitrogen atmosphere, the heating rate is set to 5℃ / min, and the temperature is raised to 1700℃ while applying a pressure of 200T. The temperature and pressure are maintained for 3 hours. After cooling, a substrate is obtained. The substrate is cut, ground, and polished to obtain the high-toughness boron nitride sintering plate.

[0031] Example 2:

[0032] A high-toughness boron nitride sintering plate comprises the following raw materials in parts by weight: 105 parts solvent, 100 parts boron nitride powder, 15 parts auxiliary materials, 3 parts additives, 3 parts sintering aids and 5 parts binder; The solvent is prepared by mixing propyl acetate and isobutanol in a volume ratio of 4:1.

[0033] Among them, yttrium oxide is selected as the sintering aid, and 3% polyvinyl alcohol aqueous solution is selected as the binder.

[0034] The additives are made from graphene oxide, Tris-HCl buffer solution, dopamine hydrochloride, deionized water, and nickel nitrate solution.

[0035] The boron nitride powder is prepared by compounding coarse, medium and fine particles, with a mass ratio of 1:0.7:0.15. The particle size of the coarse particles is 13μm, the particle size of the medium particles is 5μm, and the particle size of the fine particles is 0.5μm.

[0036] The auxiliary material was prepared by the following method: Deionized water was added to a mixer and heated to 90°C. Boric acid and melamine were then added sequentially, and the temperature was raised to 95°C and held for 1-2 hours. Heating was then stopped, and the mixture was stirred at 300 rpm for 25 minutes. The resulting product was centrifuged, dried, and then placed in a tube furnace. The temperature was raised to 710°C at a rate of 4°C / min and held for 2.5 hours. The resulting product was dispersed in ethanol at a mass ratio of 1:50 and ultrasonically treated at 250W for 35 minutes. Deionized water at 40% of the ethanol mass was added, and the resulting product was subjected to solvent exchange with tert-butanol three times. Subsequently, it was freeze-dried at -50°C for 48 hours to obtain the auxiliary material.

[0037] The mass ratio of boric acid to melamine is 1:0.85, and the total mass of boric acid and melamine is 7% of the mass of deionized water.

[0038] The additive was prepared by the following method: graphene oxide was dispersed in Tris-HCl buffer solution and ultrasonically dispersed at 400W for 1.5h to obtain a dispersion. Dopamine hydrochloride was added to the dispersion and stirred at 150rpm for 7h in a mixer to obtain a coarse material. The coarse material was dispersed in deionized water, nickel nitrate solution was added, and stirred at 300rpm for 4h. The resulting product was freeze-dried and then sent to a tube furnace. A mixed gas was introduced, and the temperature was raised to 500℃ at a rate of 3℃ / min and held for 1.5h to obtain a preparative material. The preparative material was dispersed in NMP, hydroxysuccinimide was added, and the reaction was carried out at 65℃ for 4.5h. Then polysiloxane was added, and the reaction was carried out at 83℃ for 5h. The resulting product was centrifuged to obtain a solid. The solid was washed with ethanol four times and then treated at 230℃ for 1.2h to obtain the additive.

[0039] The mass ratio of graphene oxide to Tris-HCl buffer solution was 1:180, the pH value of Tris-HCl buffer solution was 8.5, the mass of dopamine hydrochloride was 0.07% of the mass of dispersion, the mass ratio of coarse material to deionized water was 1:18, the mass of nickel nitrate solution was 35% of the mass of deionized water, the mass concentration of nickel nitrate solution was 4%, the mass ratio of pre-material to NMP was 1:550, the mass of hydroxysuccinimide was 35% of the mass of pre-material, and the mass of polysiloxane was 15% of the mass of pre-material.

[0040] The mixed gas flow rate is 110 sccm, and the mixed gas is prepared by mixing 5% hydrogen and 95% argon.

[0041] A method for preparing a high-toughness boron nitride sintering plate includes the following steps: solvent, boron nitride powder, auxiliary materials, additives, sintering aids, and binders are weighed as needed and added to a mixer. The mixer is set to 80 rpm and stirred for 40 minutes to obtain a slurry. The slurry is spray-dried to obtain powder. The powder is sieved through a 110-mesh sieve and then placed into a mold. The powder is statically pressed under a pressure of 85 MPa to obtain a green blank. The green blank is then placed in a sintering furnace. Under a nitrogen atmosphere, the heating rate is set to 8℃ / min, and the temperature is raised to 1800℃ while applying a pressure of 200T. The temperature and pressure are maintained for 3.5 hours. After cooling, a substrate is obtained. The substrate is cut, ground, and polished to obtain the high-toughness boron nitride sintering plate.

[0042] Example 3:

[0043] A high-toughness boron nitride sintering plate comprises the following raw materials in parts by weight: 110 parts solvent, 110 parts boron nitride powder, 20 parts auxiliary materials, 4 parts additives, 4 parts sintering aids and 6 parts binder; The solvent is prepared by mixing propyl acetate and isobutanol in a volume ratio of 4:1.

[0044] Among them, yttrium oxide is selected as the sintering aid, and 3% polyvinyl alcohol aqueous solution is selected as the binder.

[0045] The additives are made from graphene oxide, Tris-HCl buffer solution, dopamine hydrochloride, deionized water, and nickel nitrate solution.

[0046] The boron nitride powder is prepared by compounding coarse, medium and fine particles, with a mass ratio of 1:0.8:0.2. The particle size of the coarse particles is 14μm, the particle size of the medium particles is 6μm and the particle size of the fine particles is 0.6μm.

[0047] The auxiliary material was prepared by the following method: Deionized water was added to a mixer and heated to 90°C. Boric acid and melamine were then added sequentially, and the temperature was raised to 95°C and held for 2 hours. Heating was then stopped, and the mixture was stirred at 400 rpm for 30 minutes. The resulting product was centrifuged, dried, and then placed in a tube furnace. The temperature was raised to 720°C at a rate of 5°C / min and held for 3 hours. The resulting product was dispersed in ethanol at a mass ratio of 1:50 and ultrasonically treated at 300W for 40 minutes. Deionized water at 50% of the ethanol mass was added, and the resulting product was subjected to solvent exchange with tert-butanol three times. Subsequently, it was freeze-dried at -50°C for 48 hours to obtain the auxiliary material.

[0048] The mass ratio of boric acid to melamine is 1:0.9, and the total mass of boric acid and melamine is 8% of the mass of deionized water.

[0049] The additive was prepared by the following method: graphene oxide was dispersed in Tris-HCl buffer solution and ultrasonically dispersed at 500W for 2 hours to obtain a dispersion. Dopamine hydrochloride was added to the dispersion and stirred at 200rpm for 8 hours in a mixer to obtain a coarse material. The coarse material was dispersed in deionized water, nickel nitrate solution was added, and stirred at 400rpm for 5 hours. The resulting product was freeze-dried and then fed into a tube furnace. A mixed gas was introduced, and the temperature was raised to 550℃ at a rate of 4℃ / min and held for 2 hours to obtain a preparative material. The preparative material was dispersed in NMP, hydroxysuccinimide was added, and the reaction was carried out at 70℃ for 5 hours. Then, polysiloxane was added, and the reaction was carried out at 85℃ for 6 hours. The resulting product was centrifuged to obtain a solid. The solid was washed with ethanol 5 times and then treated at 250℃ for 1.5 hours to obtain the additive.

[0050] The mass ratio of graphene oxide to Tris-HCl buffer solution was 1:200, the pH value of Tris-HCl buffer solution was 8.5, the mass of dopamine hydrochloride was 0.08% of the mass of dispersion, the mass ratio of coarse material to deionized water was 1:20, the mass of nickel nitrate solution was 40% of the mass of deionized water, the mass concentration of nickel nitrate solution was 5%, the mass ratio of pre-material to NMP was 1:600, the mass of hydroxysuccinimide was 40% of the mass of pre-material, and the mass of polysiloxane was 20% of the mass of pre-material.

[0051] The mixed gas flow rate is 120 sccm, and the mixed gas is prepared by mixing 5% hydrogen and 95% argon.

[0052] A method for preparing a high-toughness boron nitride sintering plate includes the following steps: solvent, boron nitride powder, auxiliary materials, additives, sintering aids, and binders are weighed as needed and added to a mixer. The mixer is set to 100 rpm and stirred for 50 minutes to obtain a slurry. The slurry is spray-dried to obtain powder. The powder is sieved through a 120-mesh sieve and then placed into a mold. The powder is statically pressed under a pressure of 90 MPa to obtain a green blank. The green blank is then placed in a sintering furnace. Under a nitrogen atmosphere, the heating rate is set to 10℃ / min, and the temperature is raised to 1900℃ while applying a pressure of 200T. The temperature and pressure are maintained for 4 hours. After cooling, a substrate is obtained. The substrate is cut, ground, and polished to obtain the high-toughness boron nitride sintering plate.

[0053] Comparative Example 1: The difference between this comparative example and Example 1 is that the boron nitride powder used in this comparative example has an equal mass of 5μm particle size.

[0054] Comparative Example 2 differs from Example 1 in that it does not contain any auxiliary materials.

[0055] Comparative Example 3 differs from Example 1 in that it does not contain any additives.

[0056] Performance testing: The performance of the boron nitride sintered plates prepared in Examples 1-3 and Comparative Examples 1-3 was tested; Bulk density: The bulk density (g / cm³) was tested according to GB / T 25995-2010 standard and recorded in Table 1; Bending strength: The bending strength (MPa) was tested according to GB / T 6569-2006 standard and recorded in Table 1; Compressive strength: The compressive strength (MPa) was tested according to GB / T 8489-2006 standard and recorded in Table 1; Thermal conductivity: The thermal conductivity [(W / (m·K)] was tested according to GB / T 22588-2008 standard and recorded in Table 1; Thermal shock resistance cycle count: The number of thermal shock resistance cycles was tested according to GB / T 37246-2018 and recorded in Table 1.

[0057] Table 1: Analysis and comparison of the data in Table 1 show that the boron nitride sintering plates prepared by the methods of Examples 1-3 have better performance than those of Comparative Examples 1-3. This indicates that the synergistic effect of multi-scale boron nitride powder gradation, aerogelated whisker network of auxiliary materials, and interface strengthening of additives has effectively achieved significant optimization of the comprehensive performance of the material. Further analysis of the data in the table reveals that Comparative Example 1 shows the most significant decrease in bulk density and thermal conductivity, along with a marked reduction in flexural and compressive strength. This indicates that single-size powders cannot achieve close packing, resulting in low green body density and inevitable porosity within the sintered body. This directly degrades the material's fundamental physical properties, hinders phonon transport, and significantly reduces thermal conductivity. Furthermore, the porosity caused by the inability to achieve close packing becomes the starting point for thermal stress concentration, leading to poor thermal shock resistance. This underscores the importance of multi-scale powder gradation. Comparative Example 2, lacking auxiliary materials, exhibits weaknesses in flexural strength and thermal shock cycle resistance, indicating that the absence of auxiliary materials... The absence of additives means the loss of the toughening mechanism. When the material is subjected to bending and thermal stress, it lacks effective crack deflection and bridging capabilities, resulting in increased brittleness. Consequently, the bending strength and thermal shock resistance are significantly reduced. In contrast, Comparative Example 3 shows a significant decrease in compressive strength and thermal conductivity after the additives are missing. This is because, although the basic skeleton and toughening network remain after the additives are missing, the interfacial bonding is weakened. During compression, slippage between components is likely to occur, leading to a decrease in compressive strength. At the same time, poor interfaces will generate a large amount of phonon scattering, reducing thermal conductivity. Insufficient interfacial bonding will also reduce the ability to resist thermal stress damage, so the thermal shock resistance is also not as good as that of the example.

[0058] By comparing and analyzing the relevant data in the table, it can be seen that the high-toughness boron nitride sintering plate prepared by this invention has good strength properties. This indicates that the high-toughness boron nitride sintering plate provided by this invention has a broader market prospect and is more suitable for widespread application.

[0059] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0060] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A high-toughness boron nitride sintering plate, characterized in that: It includes the following raw materials by weight: 100-110 parts solvent, 90-110 parts boron nitride powder, 10-20 parts auxiliary materials, 2-4 parts additives, 2-4 parts sintering aids and 4-6 parts binder; The additive's raw materials include graphene oxide, Tris-HCl buffer solution, dopamine hydrochloride, deionized water, and nickel nitrate solution.

2. The high-toughness boron nitride sintering plate according to claim 1, characterized in that, The boron nitride powder is prepared by compounding coarse, medium and fine particles, with a mass ratio of 1:0.6-0.8:0.1-0.

2. The particle size of the coarse particles is selected as 11-14 μm, the particle size of the medium particles is selected as 3-6 μm, and the particle size of the fine particles is selected as 0.3-0.6 μm.

3. The high-toughness boron nitride sintering plate according to claim 1, characterized in that, The auxiliary material is prepared by the following method: Deionized water is added to a mixer and heated to 90°C. Boric acid and melamine are then added sequentially, and the temperature is raised to 95°C and maintained for 1-2 hours. Heating is then stopped, and the mixture is stirred at 200-400 rpm for 20-30 minutes. The resulting product is centrifuged, dried, and then placed in a tube furnace. The temperature is raised to 700-720°C at a rate of 3-5°C / min and maintained for 2-3 hours. The resulting product is dispersed in ethanol at a mass ratio of 1:50 and ultrasonically treated at 200-300W for 30-40 minutes. Deionized water at 30-50% of the ethanol mass is added. The resulting product is subjected to solvent exchange with tert-butanol three times, followed by freeze-drying at -50°C for 48 hours to obtain the auxiliary material.

4. The high-toughness boron nitride sintering plate according to claim 3, characterized in that, The mass ratio of boric acid to melamine is 1:0.8 to 0.9, and the total mass of boric acid and melamine is 6 to 8% of the mass of deionized water.

5. The high-toughness boron nitride sintering plate according to claim 1, characterized in that, The additive is prepared by the following method: graphene oxide is dispersed in a Tris-HCl buffer solution and ultrasonically dispersed at 300-500W for 1-2 hours to obtain a dispersion. Dopamine hydrochloride is added to the dispersion, and the mixture is stirred at 100-200rpm in a mixer for 6-8 hours to obtain a coarse material. The coarse material is dispersed in deionized water, nickel nitrate solution is added, and the mixture is stirred at 200-400rpm for 3-5 hours. The resulting product is freeze-dried and then fed into a tube furnace for mixing. The gas was heated at a rate of 2–4 °C / min to 450–550 °C and held for 1–2 h to obtain a preparative material. The preparative material was dispersed in NMP, and hydroxysuccinimide was added. The reaction was carried out at 60–70 °C for 4–5 h. Then, polysiloxane was added and the reaction was carried out at 80–85 °C for 4–6 h. The resulting product was centrifuged to obtain a solid. The solid was washed with ethanol 3–5 times and then treated at 200–250 °C for 1–1.5 h to obtain an additive.

6. The high-toughness boron nitride sintering plate according to claim 5, characterized in that, The mass ratio of graphene oxide to Tris-HCl buffer solution is 1:150-200, the pH value of Tris-HCl buffer solution is 8.5, the mass of dopamine hydrochloride is 0.06-0.08% of the dispersion mass, the mass ratio of coarse material to deionized water is 1:15-20, the mass of nickel nitrate solution is 30-40% of the deionized water mass, the mass concentration of nickel nitrate solution is 2-5%, the mass ratio of pre-material to NMP is 1:500-600, the mass of hydroxysuccinimide is 30-40% of the pre-material mass, and the mass of polysiloxane is 10-20% of the pre-material mass.

7. The high-toughness boron nitride sintering plate according to claim 5, characterized in that, The mixed gas is introduced at a rate of 100-120 sccm, and the mixed gas is prepared by mixing 5% hydrogen and 95% argon.

8. The high-toughness boron nitride sintering plate according to claim 1, characterized in that, The solvent is prepared by mixing propyl acetate and isobutanol in a volume ratio of 4:

1.

9. The high-toughness boron nitride sintering plate according to claim 1, characterized in that, The sintering aid is yttrium oxide, and the binder is a 3% polyvinyl alcohol aqueous solution.

10. The method for preparing the high-toughness boron nitride sintering plate according to any one of claims 1 to 9, characterized in that, The process includes the following steps: Weigh out the solvent, boron nitride powder, auxiliary materials, additives, sintering aids, and binder as needed and add them to a mixer. Set the mixer to 60-100 rpm and stir for 30-50 minutes to obtain a slurry. Spray dry the slurry to obtain powder. Sift the powder through a 100-120 mesh sieve and then load it into a mold. Perform static pressing under a pressure of 80-90 MPa to obtain a green blank. Send the green blank into a sintering furnace. Under a nitrogen atmosphere, set the heating rate to 5-10℃ / min and heat to 1700-1900℃ while applying a pressure of 200T. Hold the temperature and pressure for 3-4 hours. After cooling, obtain the substrate. Cut, grind, and polish the substrate to obtain a high-toughness boron nitride sintering plate.

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