Preparation method of high-strength heat insulation tile composite material

Abstract

The invention provides a preparation method of a high-strength heat-insulating tile composite material, and belongs to the technical field of heat-insulating tile composite materials. The preparation method comprises the following steps: modifying boron nitride nanowires, preparing a boron nitride particle / zirconium oxide fiber compound, forming and calcining. The preparation method of the composite sol comprises the following steps: dissolving yttrium nitrate in absolute ethyl alcohol, and adding gluconic acid and triethanolamine to obtain a solution I; adding tetraethoxysilane into absolute ethyl alcohol, uniformly stirring, adjusting the pH value to 2.2-2.4, and stirring for 27-32 minutes at the temperature of 40-45 DEG C to obtain a solution II; adding the solution I into the solution II, and stirring at 60-65 DEG C for 2.2-2.8 hours to obtain a composite glue solution; the heat insulation tile composite material prepared by the method is high in strength, good in heat insulation performance and excellent in high-temperature stability.

Description

Technical Field

[0001] The invention belongs to the technical field of thermal insulation tile composite materials, and particularly relates to a preparation method of a high-strength thermal insulation tile composite material. Background Art

[0002] Thermal insulation tiles are a material with high-efficiency thermal insulation properties, usually made of a composite of ceramic, carbon fiber or other special materials. When an aircraft flies at high speed in the atmosphere, the intense friction with the air will generate extremely high temperatures. Thermal insulation tiles are an important component of the protection system on the surface of the aircraft. They can isolate high temperatures when flying at high speeds or re-entering the atmosphere, and can effectively block heat from entering the interior of the aircraft, protecting the aircraft's structure and internal equipment from high-temperature damage, ensuring the safe operation of the aircraft.

[0003] With the continuous increase in aircraft flight speed and increasingly stringent flight performance requirements, higher requirements are placed on the strength of thermal insulation tiles. High-strength thermal insulation tiles can not only better withstand the aerodynamic loads and mechanical stresses during flight, but also ensure structural stability in high-temperature environments, avoiding problems such as breakage and falling off due to insufficient strength, thereby improving the safety and reliability of aircraft.

[0004] At present, the preparation method of high-strength thermal insulation tile composite materials mainly adopts the fiber reinforcement method, which improves the strength by adding fiber reinforcements such as quartz fiber and carbon fiber to the matrix material. However, the interface bonding performance between the fiber and the matrix is ​​poor, and there is a problem of uneven dispersion between the fiber and the matrix, which easily leads to the local strength of the thermal insulation tile composite material being too high or too low, affecting the overall performance of the composite material. CN118851783A discloses high-strength, low-thermal-conductivity ceramic fiber cotton-based insulation tiles and a preparation method thereof. Specifically, the invention discloses mixing a high-temperature binder and a soluble starch to obtain a mixed powder, dispersing the mixed powder in anhydrous ethanol and stirring evenly to obtain a mixed liquid; dispersing the dispersant in high-purity water and stirring evenly to obtain a solvent; adding the mixed liquid and ceramic fiber cotton to the solvent, stirring and dispersing evenly to obtain a mixed slurry; pouring the mixed slurry into a mold, vacuum filtering, and obtaining a wet blank; and drying and sintering the wet blank to obtain the ceramic fiber cotton-based insulation tile. This patent adds a dispersant to the solvent, which is conducive to the dispersion of fiber cotton. The resulting thermal insulation tile material has a room temperature compressive strength of 3.9 MPa and an average linear expansion coefficient of 0.32×10 -6 / ℃(RT~700℃); Although the thermal insulation tile material obtained by this patent improves the compressive strength and reduces the linear expansion coefficient to a certain extent, its strength will drop rapidly in an environment above 1000°C, affecting its use in ultra-high temperature environments.

[0005] In addition, during the research and development process, technicians also found that in a high-temperature environment with rapid temperature rise, the insulation tile composite material is prone to cracks, which in turn destroys the overall structure, reduces the mechanical properties, and ultimately shortens the service life of the insulation tile composite material. Summary of the Invention

[0006] In order to solve the technical problems existing in the prior art, the present invention provides a method for preparing a high-strength thermal insulation tile composite material, which improves the strength performance, still has high strength in an environment above 1000°C, and ensures excellent stability in a high-temperature environment with rapid heating.

[0007] In order to solve the above technical problems, the present invention adopts the following technical solutions: A method for preparing a high-strength thermal insulation tile composite material includes the steps of modifying boron nitride nanowires, preparing a boron nitride particle / zirconia fiber composite, molding, and calcining. The specific operations are as follows: 1. Boron nitride nanowire modification (1) Pretreatment of Boron Nitride Nanowires The boron nitride nanowires are subjected to plasma treatment in an oxygen atmosphere at a power of 95-106 W for 4-6 minutes, and plasma-treated boron nitride nanowires are obtained after the treatment. The boron nitride nanowires have a length of 4.5-4.8 μm and a diameter of 12-18 nm; (2) Preparation of composite sol Dissolve yttrium nitrate in anhydrous ethanol. After complete dissolution, add gluconic acid and triethanolamine, raise the temperature to 57-62°C, and stir at 210-230 rpm for 0.8-1.2 hours to obtain solution one; add ethyl orthosilicate to anhydrous ethanol, stir evenly, add 23-27wt% nitric acid solution to adjust the pH to 2.2-2.4, and stir at 40-45°C for 27-32 minutes to obtain solution two; slowly add solution one to solution two at a rate of 0.8-1.2 mL / min, and heat while adding at a rate of 2.5-3.5°C / min to 60-65°C, stop heating, and after the addition is complete, stir at 60-65°C for 2.2-2.8 hours to obtain a composite glue; In the first solution, the mass volume ratio of yttrium nitrate, anhydrous ethanol, gluconic acid and triethanolamine is 6.8-7.2 g:100 mL:1.0-1.4 g:0.5-0.8 g; The mass volume ratio of the ethyl orthosilicate and anhydrous ethanol is 3.8-4.2 g:100 mL; The volume ratio of the second solution to the first solution is 48-53:50-55; (3) Impregnation Plasma-treated boron nitride nanowires were added to the composite glue solution for ultrasonic dispersion, with an ultrasonic time of 36-45 minutes, an ultrasonic power of 130-150W, and an ultrasonic frequency of 30-35kHz. After the ultrasonic treatment, the solution was allowed to stand for 17-22 hours, and then dried at -28 to -22°C for 10-14 hours, and then dried at -47 to -42°C for 10-14 hours. After drying, the solution was naturally restored to room temperature, and then placed in a muffle furnace, and the temperature was increased to 800-815°C at a rate of 2.5-3.5°C / min, kept warm for 2.0-2.5 hours, and cooled to room temperature with the furnace to obtain modified boron nitride nanowires. The mass ratio of the plasma-treated boron nitride nanowires to the composite glue is 9.5-10.6:100.

[0008] 2. Preparation of Boron Nitride Particle / Zirconium Oxide Fiber Composites Aluminum nitrate is added to anhydrous ethanol, and N-octanoyl-N-methylglucamine and polyvinylpyrrolidone are added and stirred to obtain an aluminum nitrate solution; zirconium oxide fiber is added to the aluminum nitrate solution, the temperature is increased to 55-58°C, and the solution is kept at this temperature and allowed to stand for 1.4-1.6 hours. After the solution is left at this temperature, the solid is filtered out, washed and dried, and then added to a calcining furnace, the temperature is increased to 600-620°C at a rate of 4.0-6.0°C / min, and the solution is kept at this temperature and calcined for 1.0-1.4 hours to obtain modified zirconium oxide fiber; The length of the zirconia fiber is 8.0-9.0 μm and the diameter is 15-25 nm; The mass ratio of the aluminum nitrate, anhydrous ethanol, N-octanoyl-N-methylglucamine and polyvinylpyrrolidone is 8.0-8.5:100:0.6-0.8:0.8-1.2; The mass ratio of the zirconia fiber to the aluminum nitrate solution is 8-12:106-115; The boron nitride particles are placed in a mixed acid solution for ball milling treatment, the ball milling time is 110-130 minutes, the ball milling speed is 200-220 rpm, the ball-to-material ratio is 2-4:1, the grinding balls are zirconia balls, and the ball milling temperature is 60-65°C. After the ball milling is completed, the solid matter is filtered out, washed and dried to obtain acid-treated boron nitride particles; the acid-treated boron nitride particles are placed in N,N-dimethylformamide, stirred evenly, and then thionyl chloride is added. The temperature is increased to 116-123°C at a rate of 1.8-2.2°C / min, and reflux reaction is carried out for 7.8-8.2 hours. Then, p-phenylenediamine and glycine are added, and the reaction is kept at 92-97°C for 10-13 hours. After the reaction is completed, modified zirconia fiber is added, and the mixture is kept stirred at 58-62°C for 36-45 minutes at a stirring speed of 240-260 rpm. After the stirring is completed, the mixture is filtered, washed and dried to obtain a boron nitride particle / zirconia fiber composite; The particle size of the boron nitride particles is 60-80 nm; The mixed acid solution is a mixture of concentrated nitric acid and concentrated sulfuric acid, wherein the volume ratio of the concentrated nitric acid to the concentrated sulfuric acid is 1:2.8-3.2; the mass concentration of the concentrated nitric acid is 66-70%, and the mass concentration of the concentrated sulfuric acid is 85-88%; The mass ratio of the boron nitride particles to the mixed acid solution is 12.0-13.0:120; The mass ratio of the acid-treated boron nitride particles, N,N-dimethylformamide, thionyl chloride, p-phenylenediamine, glycine, and modified zirconia fibers is 13.0-14.0:110-130:190-210:1.1-1.4:1.3-1.7:2.8-3.2.

[0009] 3. Molding The modified boron nitride nanowires, boron nitride particles / zirconium oxide fiber composite and ethanol solution are mixed, ammonium polyacrylate is added and stirred evenly, kH792 and isopropyl tri(dioctyl pyrophosphate) titanate are added, and the mixture is stirred and reacted at 54-57° C. for 0.8-1.2 hours to obtain a molding slurry; the molding slurry is placed in a mold, and filter-pressed to obtain a molding body; The mass ratio of the modified boron nitride nanowires, boron nitride particles / zirconium oxide fiber composite, ethanol solution, ammonium polyacrylate, kH792 and isopropyl tris(dioctyl pyrophosphate) titanate is 3.0-3.5:16.5-17.0:100:1.0-1.4:0.8-1.2:0.8-1.1; The mass concentration of the ethanol solution is 23-27%.

[0010] 4. Calcination The formed body is placed in a calcining furnace, the temperature is increased to 750-800°C at a rate of 2.5-3.5°C / min, kept warm for 20-30 minutes, then the temperature is increased to 1300-1330°C at a rate of 1.5-2.5°C / min, kept warm for 2.0-2.5 hours, and cooled to room temperature with the furnace to obtain a thermal insulation tile composite material.

[0011] Compared with the prior art, the present invention has achieved the following beneficial effects: 1. The present invention prepares a thermal insulation tile composite material, using boron nitride particles and zirconium oxide fibers as a matrix and boron nitride nanowires as reinforcement. Boron nitride nanowires have good high temperature resistance, low thermal conductivity, good thermal insulation performance, and can inhibit crack propagation. Specifically, the boron nitride nanowires are first treated with oxygen plasma. High-energy particles bombard the surface of the boron nitride nanowires, causing them to undergo an oxidation reaction, thereby introducing hydroxyl and carboxyl oxygen-containing functional groups on the surface of the boron nitride nanowires, thereby increasing the surface activity. The composite sol is then treated. The composite sol is prepared by combining yttrium oxide sol and silica sol. During the sol mixing process, Y 3+ It will react with the hydroxyl groups on the surface of the silica sol to form YO-Si bonds, thereby generating yttrium oxide-silica composite sol, forming a stable sol network structure. After the oxygen plasma-treated boron nitride nanowires are impregnated, an yttrium oxide-silica ceramic phase will be formed, which will bond the boron nitride nanowires together to obtain a porous skeleton structure, providing strength support for the thermal insulation tile composite material, and improving its mechanical properties, thermal insulation properties and high temperature resistance. In the preparation step of the boron nitride particle / zirconia fiber composite, an alumina coating is first coated on the surface of the zirconia fiber to improve the toughness and high temperature resistance of the fiber, and to improve the compatibility with the boron nitride particles. The boron nitride particles are then carboxylated, and acyl chloride groups are introduced through thionyl chloride. Then, amino compounds such as p-phenylenediamine and glycine are added. , which undergoes an amidation reaction with the acyl chloride group, and the amino group can combine with the aluminum oxide on the surface of the zirconia fiber, ultimately enhancing the binding force between the boron nitride particles and the zirconia fiber, forming a three-dimensional network structure, and enhancing the strength and stability of the thermal insulation tile composite material; in the molding step, ammonium polyacrylate is used as a dispersant and a coupling agent is used as an interface compatibilizer to improve the binding between the zirconia fiber, boron nitride nanowires and the interface of the boron nitride particles, and enhance the compatibility with ammonium polyacrylate, thereby obtaining a molding slurry with good homogeneity; the present invention adopts a combination of specific components and specific methods, which ultimately improves the strength and thermal insulation properties of the thermal insulation tile composite material, and improves the strength retention rate at high temperatures, avoids cracks when used in a high temperature environment, and ensures the stability of the composite material; 2. The high-strength thermal insulation tile composite material prepared by the preparation method of the present invention has a thermal conductivity of 0.033-0.037W / (m·K) and a fracture toughness of 1.51-1.57MPa·m 1 / 2 , compressive strength is 5.48-5.56MPa, flexural strength is 2.42-2.48MPa, and compression strength is 6.35-6.41MPa; 3. The high-strength thermal insulation tile composite material prepared by the preparation method of the present invention was heated to 1300°C at a rate of 5.0°C / min, kept at this temperature for 10 days, and the fracture toughness was measured again to be 1.44-1.52 MPa·m 1 / 2 , compressive strength is 5.21-5.35MPa, flexural strength is 2.30-2.39MPa, and compression strength is 5.98-6.13MPa; 4. The high-strength thermal insulation tile composite material prepared by the preparation method of the present invention was heated to 1000°C at a rate of 60°C / min, kept at this temperature for 120 hours, then heated to 1300°C at a rate of 50°C / min and kept at this temperature for 120 hours. The fracture toughness was again measured to be 1.42-1.49 MPa·m 1 / 2 , the compressive strength is 5.13-5.25MPa, the flexural strength is 2.27-2.35MPa, and the compressive strength is 5.92-6.01MPa. DETAILED DESCRIPTION

[0012] In order to more clearly understand the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described.

[0013] Example 1 1. Boron nitride nanowire modification (1) Pretreatment of Boron Nitride Nanowires The boron nitride nanowires were subjected to plasma treatment in an oxygen atmosphere at a power of 106 W for 4 minutes, and plasma-treated boron nitride nanowires were obtained after the treatment. The boron nitride nanowire has a length of 4.8 μm and a diameter of 18 nm; (2) Preparation of composite sol 7.2 g of yttrium nitrate was dissolved in 100 mL of anhydrous ethanol. After complete dissolution, 1.4 g of gluconic acid and 0.8 g of triethanolamine were added, the temperature was raised to 62 ° C, and the mixture was stirred at 230 rpm for 0.8 h to obtain solution 1; 4.2 g of ethyl orthosilicate was added to 100 mL of anhydrous ethanol, and the mixture was stirred evenly. 27 wt% nitric acid solution was added to adjust the pH to 2.4, and the mixture was stirred at 45 ° C for 32 min to obtain solution 2; 55 mL of solution 1 was slowly added to 53 mL of solution 2 at a rate of 1.2 mL / min. The temperature was raised while the mixture was added at a rate of 3.5 ° C / min. The temperature was raised to 65 ° C, and the temperature was stopped. After the addition was completed, the mixture was kept warm and stirred at 65 ° C for 2.2 h to obtain a composite glue; (3) Impregnation 10.6 g of plasma-treated boron nitride nanowires were put into 100 g of composite glue for ultrasonic dispersion. The ultrasonic time was 45 min, the ultrasonic power was 150 W, and the ultrasonic frequency was 35 kHz. After the ultrasonic treatment, the mixture was allowed to stand for 22 h, then dried at -22 ° C for 14 h and at -42 ° C for 14 h. After drying, the mixture was naturally restored to room temperature and put into a muffle furnace. The temperature was increased to 815 ° C at a rate of 3.5 ° C / min, kept warm for 2.0 h, and cooled to room temperature with the furnace to obtain modified boron nitride nanowires.

[0014] 2. Preparation of Boron Nitride Particle / Zirconium Oxide Fiber Composites 8.5 g of aluminum nitrate was added to 100 g of anhydrous ethanol, 0.8 g of N-octanoyl-N-methylglucamine and 1.2 g of polyvinylpyrrolidone were added, and the mixture was stirred evenly to obtain an aluminum nitrate solution; 12 g of zirconia fiber was added to 115 g of the aluminum nitrate solution, the temperature was increased to 58° C., and the mixture was kept at this temperature for 1.6 h. After the solution was left at this temperature, the solid was filtered out, washed and dried, and then placed in a calcining furnace, the temperature was increased to 620° C. at a rate of 6.0° C. / min, and the mixture was kept at this temperature for 1.0 h to obtain a modified zirconia fiber; The zirconia fiber has a length of 9.0 μm and a diameter of 25 nm; 13.0 g of boron nitride particles were placed in 120 g of mixed acid solution for ball milling treatment. The ball milling time was 130 min, the ball milling speed was 220 rpm, the ball-to-material ratio was 4:1, the grinding balls were zirconia balls, and the ball milling temperature was 65 ° C. After the ball milling was completed, the solid matter was filtered out, washed and dried to obtain acid-treated boron nitride particles; 14.0 g of acid-treated boron nitride particles were placed in 130 g of N, N-dimethylformamide, stirred evenly, and then 210 g of thionyl chloride was added. The temperature was increased to 123 ° C at a rate of 2.2 ° C / min, and refluxed for 8.2 h. Then, 1.4 g of p-phenylenediamine and 1.7 g of glycine were added, and the mixture was kept warm at 97 ° C for 10 h. After the reaction was completed, 3.2 g of modified zirconia fiber was added, and the mixture was kept warm and stirred at 62 ° C for 36 min with a stirring speed of 260 rpm. After the stirring was completed, the mixture was filtered, washed and dried to obtain a boron nitride particle / zirconia fiber composite; The particle size of the boron nitride particles is 80 nm; The mixed acid solution is a mixture of concentrated nitric acid and concentrated sulfuric acid, the volume ratio of the concentrated nitric acid to the concentrated sulfuric acid is 1:3.2; the mass concentration of the concentrated nitric acid is 70%, and the mass concentration of the concentrated sulfuric acid is 88%.

[0015] 3. Molding 3.5 g of modified boron nitride nanowires, 17.0 g of boron nitride particles / zirconium oxide fiber composites were mixed with 100 g of 27 wt % ethanol solution, 1.4 g of ammonium polyacrylate was added and stirred evenly, and then 1.2 g of kH792 and 1.1 g of isopropyl tri(dioctyl pyrophosphate) titanate were added. The mixture was stirred and reacted at 57 ° C for 0.8 h to obtain a molding slurry; the molding slurry was placed in a mold and filter-pressed to obtain a molded body.

[0016] 4. Calcination The formed body was placed in a calcining furnace, the temperature was increased to 800°C at a rate of 3.5°C / min, kept warm for 20 minutes, then the temperature was increased to 1330°C at a rate of 2.5°C / min, kept warm for 2.0 hours, and cooled to room temperature with the furnace to obtain a thermal insulation tile composite material.

[0017] Example 2 1. Boron nitride nanowire modification (1) Pretreatment of Boron Nitride Nanowires The boron nitride nanowires were subjected to plasma treatment in an oxygen atmosphere at a power of 95 W for 6 minutes, and plasma-treated boron nitride nanowires were obtained after the treatment. The boron nitride nanowire has a length of 4.5 μm and a diameter of 12 nm; (2) Preparation of composite sol 6.8 g of yttrium nitrate was dissolved in 100 mL of anhydrous ethanol. After complete dissolution, 1.0 g of gluconic acid and 0.5 g of triethanolamine were added, the temperature was raised to 57°C, and the mixture was stirred at 210 rpm for 1.2 h to obtain solution 1. 3.8 g of ethyl orthosilicate was added to 100 mL of anhydrous ethanol, and the mixture was stirred evenly. 23 wt% nitric acid solution was added to adjust the pH to 2.2, and the mixture was stirred at 40°C for 27 min to obtain solution 2. 50 mL of solution 1 was slowly added to 48 mL of solution 2 at a rate of 0.8 mL / min. The temperature was raised while the mixture was added at a rate of 2.5°C / min to 60°C, and the temperature was stopped. After the addition was completed, the mixture was kept stirred at 60°C for 2.8 h to obtain a composite adhesive solution. (3) Impregnation 9.5 g of plasma-treated boron nitride nanowires were added to 100 g of composite glue for ultrasonic dispersion. The ultrasonic time was 36 min, the ultrasonic power was 130 W, and the ultrasonic frequency was 30 kHz. After the ultrasonic treatment, the mixture was allowed to stand for 17 h, then dried at -28 ° C for 10 h and at -47 ° C for 10 h. After drying, the mixture was naturally restored to room temperature and placed in a muffle furnace. The temperature was increased to 800 ° C at a rate of 2.5 ° C / min, kept warm for 2.5 h, and cooled to room temperature with the furnace to obtain modified boron nitride nanowires.

[0018] 2. Preparation of Boron Nitride Particle / Zirconium Oxide Fiber Composites 8.0 g of aluminum nitrate was added to 100 g of anhydrous ethanol, 0.6 g of N-octanoyl-N-methylglucamine and 0.8 g of polyvinylpyrrolidone were added, and the mixture was stirred evenly to obtain an aluminum nitrate solution; 8 g of zirconia fiber was added to 106 g of the aluminum nitrate solution, the temperature was increased to 55° C., and the mixture was kept at this temperature for 1.4 h. After the solution was left at this temperature, the solid was filtered out, washed and dried, and then placed in a calcining furnace, the temperature was increased to 600° C. at a rate of 4.0° C. / min, and the mixture was kept at this temperature for 1.4 h to obtain a modified zirconia fiber; The zirconia fiber has a length of 8.0 μm and a diameter of 15 nm; 12.0 g of boron nitride particles were placed in 120 g of mixed acid solution for ball milling treatment. The ball milling time was 110 min, the ball milling speed was 200 rpm, the ball-to-material ratio was 2:1, the grinding balls were zirconia balls, and the ball milling temperature was 60 ° C. After the ball milling was completed, the solid matter was filtered out, washed and dried to obtain acid-treated boron nitride particles; 13.0 g of acid-treated boron nitride particles were placed in 110 g of N, N-dimethylformamide, stirred evenly, and then 190 g of thionyl chloride was added. The temperature was increased to 116 ° C at a rate of 1.8 ° C / min, and refluxed for 7.8 h. Then, 1.1 g of p-phenylenediamine and 1.3 g of glycine were added, and the mixture was kept warm at 92 ° C for 13 h. After the reaction was completed, 2.8 g of modified zirconia fiber was added, and the mixture was kept warm and stirred at 58 ° C for 45 min with a stirring speed of 240 rpm. After the stirring was completed, it was filtered, washed and dried to obtain a boron nitride particle / zirconia fiber composite; The particle size of the boron nitride particles is 60 nm; The mixed acid solution is a mixture of concentrated nitric acid and concentrated sulfuric acid, and the volume ratio of the concentrated nitric acid to the concentrated sulfuric acid is 1:2.8; the mass concentration of the concentrated nitric acid is 66%, and the mass concentration of the concentrated sulfuric acid is 85%.

[0019] 3. Molding 3.0 g of modified boron nitride nanowires, 16.5 g of boron nitride particles / zirconium oxide fiber composites were mixed with 100 g of 23 wt% ethanol solution, 1.0 g of ammonium polyacrylate was added and stirred evenly, and then 0.8 g of kH792 and 0.8 g of isopropyl tri(dioctyl pyrophosphate) titanate were added. The mixture was stirred and reacted at 54 ° C for 1.2 h to obtain a molding slurry; the molding slurry was placed in a mold and filter-pressed to obtain a molded body.

[0020] 4. Calcination The formed body was placed in a calcining furnace, the temperature was increased to 750°C at a rate of 2.5°C / min, kept warm for 30 minutes, then the temperature was increased to 1300°C at a rate of 1.5°C / min, kept warm for 2.5 hours, and cooled to room temperature with the furnace to obtain a thermal insulation tile composite material.

[0021] Example 3 1. Boron nitride nanowire modification (1) Pretreatment of Boron Nitride Nanowires The boron nitride nanowires were subjected to plasma treatment in an oxygen atmosphere at a power of 100 W for 5 minutes to obtain plasma-treated boron nitride nanowires. The boron nitride nanowire has a length of 5.0 μm and a diameter of 15 nm; (2) Preparation of composite sol 7.1 g of yttrium nitrate was dissolved in 100 mL of anhydrous ethanol. After complete dissolution, 1.2 g of gluconic acid and 0.7 g of triethanolamine were added, the temperature was raised to 60°C, and the mixture was stirred at 220 rpm for 1.0 h to obtain solution 1. 4.0 g of ethyl orthosilicate was added to 100 mL of anhydrous ethanol, and the mixture was stirred evenly. 25 wt% nitric acid solution was added to adjust the pH to 2.3, and the mixture was stirred at 42°C for 30 min to obtain solution 2. 52 mL of solution 1 was slowly added to 50 mL of solution 2 at a rate of 1.0 mL / min. The temperature was raised while the mixture was added at a rate of 3.0°C / min to 63°C, and the temperature was stopped. After the addition was completed, the mixture was kept at 63°C and stirred for 2.5 h to obtain a composite adhesive solution. (3) Impregnation 10g of plasma-treated boron nitride nanowires were put into 100g of composite glue for ultrasonic dispersion. The ultrasonic time was 40min, the ultrasonic power was 140W, and the ultrasonic frequency was 32kHz. After the ultrasonic treatment, it was allowed to stand for 20h, and then dried at -25°C for 12h and at -45°C for 12h. After drying, it was naturally restored to room temperature and put into a muffle furnace. The temperature was increased to 810°C at a rate of 3.0°C / min, kept warm for 2.3h, and cooled to room temperature with the furnace to obtain modified boron nitride nanowires.

[0022] 2. Preparation of Boron Nitride Particle / Zirconium Oxide Fiber Composites 8.3 g of aluminum nitrate was added to 100 g of anhydrous ethanol, 0.7 g of N-octanoyl-N-methylglucamine and 1.0 g of polyvinylpyrrolidone were added, and the mixture was stirred evenly to obtain an aluminum nitrate solution; 10 g of zirconia fiber was added to 110 g of the aluminum nitrate solution, the temperature was increased to 56° C., and the solution was kept at this temperature for 1.5 h. After the solution was kept at this temperature, the solid was filtered out, washed and dried, and then placed in a calcining furnace, the temperature was increased to 610° C. at a rate of 5.0° C. / min, and the solution was kept at this temperature for 1.2 h to obtain a modified zirconia fiber; The length of the zirconia fiber is 8.5 μm and the diameter is 20 nm; 12.5 g of boron nitride particles were placed in 120 g of mixed acid solution for ball milling treatment. The ball milling time was 120 min, the ball milling speed was 210 rpm, the ball-to-material ratio was 3:1, the grinding balls were zirconia balls, and the ball milling temperature was 63 ° C. After the ball milling was completed, the solid matter was filtered out, washed and dried to obtain acid-treated boron nitride particles; 13.5 g of acid-treated boron nitride particles were placed in 120 g of N, N-dimethylformamide, stirred evenly, and then 200 g of thionyl chloride was added. The temperature was increased to 120 ° C at a rate of 2.0 ° C / min, and refluxed for 8.0 h. Then, 1.3 g of p-phenylenediamine and 1.5 g of glycine were added, and the mixture was kept warm at 95 ° C for 12 h. After the reaction was completed, 3.0 g of modified zirconia fiber was added, and the mixture was kept warm and stirred at 60 ° C for 40 min with a stirring speed of 250 rpm. After the stirring was completed, the mixture was filtered, washed and dried to obtain a boron nitride particle / zirconia fiber composite; The particle size of the boron nitride particles is 70 nm; The mixed acid solution is a mixture of concentrated nitric acid and concentrated sulfuric acid, the volume ratio of the concentrated nitric acid to the concentrated sulfuric acid is 1:3; the mass concentration of the concentrated nitric acid is 68%, and the mass concentration of the concentrated sulfuric acid is 87%.

[0023] 3. Molding 3.3 g of modified boron nitride nanowires, 16.7 g of boron nitride particles / zirconium oxide fiber composites were mixed with 100 g of 25 wt% ethanol solution, 1.2 g of ammonium polyacrylate was added and stirred evenly, and then 1.0 g of kH792 and 1.0 g of isopropyl tri(dioctyl pyrophosphate) titanate were added. The mixture was stirred and reacted at 55 ° C for 1.0 h to obtain a molding slurry; the molding slurry was placed in a mold and filter-pressed to obtain a molded body.

[0024] 4. Calcination The formed body was placed in a calcining furnace, the temperature was increased to 780°C at a rate of 3.0°C / min, kept warm for 25 minutes, then the temperature was increased to 1320°C at a rate of 2.0°C / min, kept warm for 2.3 hours, and cooled to room temperature with the furnace to obtain a thermal insulation tile composite material.

[0025] The present invention prepares a thermal insulation tile composite material, using boron nitride particles and zirconium oxide fibers as a matrix and boron nitride nanowires as a reinforcement. The boron nitride nanowires have good high-temperature resistance, low thermal conductivity, good thermal insulation performance, and can hinder crack propagation. Specifically, the boron nitride nanowires are first treated with oxygen plasma. High-energy particles bombard the surface of the boron nitride nanowires, causing them to undergo an oxidation reaction, thereby introducing hydroxyl and carboxyl oxygen-containing functional groups on the surface of the boron nitride nanowires, thereby increasing the surface activity. The composite sol is then treated. The composite sol is prepared by combining yttrium oxide sol and silica sol. During the sol mixing process, Y 3+It will react with the hydroxyl groups on the surface of the silica sol to form YO-Si bonds, thereby generating yttrium oxide-silica composite sol, forming a stable sol network structure. After the oxygen plasma-treated boron nitride nanowires are impregnated, an yttrium oxide-silica ceramic phase will be formed, which will bond the boron nitride nanowires together to obtain a porous skeleton structure, providing strength support for the thermal insulation tile composite material, and improving its mechanical properties, thermal insulation properties and high temperature resistance. In the preparation step of the boron nitride particle / zirconia fiber composite, an alumina coating is first coated on the surface of the zirconia fiber to improve the toughness and high temperature resistance of the fiber, and to improve the compatibility with the boron nitride particles. The boron nitride particles are then carboxylated, and acyl chloride groups are introduced through thionyl chloride. Then, amino compounds such as p-phenylenediamine and glycine are added. , which undergoes an amidation reaction with the acyl chloride group, and the amino group can combine with the aluminum oxide on the surface of the zirconia fiber, ultimately enhancing the bonding force between the boron nitride particles and the zirconia fiber, forming a three-dimensional network structure, which can enhance the strength and stability of the thermal insulation tile composite material; in the molding step, ammonium polyacrylate is used as a dispersant and a coupling agent is used as an interface compatibilizer to improve the bonding between the zirconia fiber, boron nitride nanowires and the interface of the boron nitride particles, enhance the compatibility with ammonium polyacrylate, and thus obtain a molding slurry with good homogeneity; the present invention adopts a combination of specific components and specific methods, which ultimately improves the strength and thermal insulation properties of the thermal insulation tile composite material, and improves the strength retention rate at high temperature, avoids cracks when used in a high temperature environment, and ensures the stability of the composite material.

[0026] Comparative Example 1 On the basis of Example 3, the following changes are made: (1) In the impregnation step of the modified boron nitride nanowires, the composite glue solution was replaced with solution 2 in equal amounts; the preparation method of the solution 2 was as follows: 4.0 g of ethyl orthosilicate was added to 100 mL of anhydrous ethanol, stirred evenly, and then 25 wt % nitric acid solution was added to adjust the pH to 2.3, and stirred at 42° C. for 30 min to obtain solution 2; (2) In the molding step, the operation step of "adding 1.0 g of kH792 and 1.0 g of isopropyl tris(dioctyl pyrophosphate) titanate and stirring the reaction at 55°C for 1.0 h" was omitted; The rest of the operations remain unchanged.

[0027] Comparative Example 1 only uses silicon dioxide to treat boron nitride nanowires, which will reduce the strength performance of the composite material on the one hand and the high-temperature stability on the other hand. In addition, Comparative Example 1 also omits the coupling agent component in the molding step, resulting in weak interfacial bonding between the components and uneven molding slurry, which ultimately reduces the strength, toughness and high-temperature stability of the composite material.

[0028] Comparative Example 2 On the basis of Example 3, the following changes are made: The steps of preparing the boron nitride particle / zirconia fiber composite are as follows: 12.5 g of boron nitride particles are placed in 120 g of mixed acid solution for ball milling, the ball milling time is 120 min, the ball milling speed is 210 rpm, the ball-to-material ratio is 3:1, the grinding balls are zirconia balls, and the ball milling temperature is 63° C. After the ball milling is completed, the solid matter is filtered out, washed and dried to obtain acid-treated boron nitride particles; 13.5 g of acid-treated boron nitride particles are placed in 120 g of N,N-dimethylformamide, after stirring evenly, 3.0 g of untreated zirconia fiber is added, and the mixture is stirred at 60° C. for 40 min at a stirring speed of 250 rpm. After the stirring is completed, the mixture is filtered, washed and dried to obtain the boron nitride particle / zirconia fiber composite; The particle size of the boron nitride particles is 70 nm; The mixed acid solution is a mixture of concentrated nitric acid and concentrated sulfuric acid, the volume ratio of the concentrated nitric acid to the concentrated sulfuric acid is 1:3; the mass concentration of the concentrated nitric acid is 68%, and the mass concentration of the concentrated sulfuric acid is 87%; The length of the zirconia fiber is 8.5 μm and the diameter is 20 nm; The rest of the operations remain unchanged.

[0029] In Comparative Example 2, the boron nitride particles were acid-treated and then directly mixed with untreated zirconia fibers. On the one hand, no aluminum oxide layer was formed on the surface of the zirconia fibers, which would result in a toughening effect on the zirconia fibers. In addition, the zirconia fibers and the acid-treated boron nitride particles were only physically mixed, resulting in poor interface bonding, which in turn reduced the thermal insulation performance and the strength and stability of the composite material.

[0030] Performance Testing 1. Basic performance The thermal insulation tile composite materials prepared by the preparation methods of Examples 1-3 and Comparative Examples 1-2 were subjected to basic performance tests at room temperature, as follows:

[0031] 2. High temperature resistance The thermal insulation tile composite materials prepared by the preparation methods of Examples 1-3 and Comparative Examples 1-2 were heated to 1300°C at a rate of 5.0°C / min, kept at this temperature for 10 days, and then tested for strength properties again. The results are as follows:

[0032] 3. Rapid heating and stable performance The thermal insulation tile composite materials prepared by the preparation methods of Examples 1-3 and Comparative Examples 1-2 were heated to 1000°C at a rate of 60°C / min, kept at this temperature for 120 hours, then heated to 1300°C at a rate of 50°C / min, kept at this temperature for 120 hours, and then tested for strength properties again. The results are as follows:

[0033] Unless otherwise specified, all percentages used in the present invention are by mass.

[0034] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or substitute equivalents for some of the technical features. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A method for preparing a high-strength thermal insulation tile composite material, characterized in that: The method includes the steps of modifying boron nitride nanowires, preparing a boron nitride particle / zirconia fiber composite, forming and calcining; The boron nitride nanowire modification includes the steps of pre-treating the boron nitride nanowire, preparing a composite sol, and impregnating; The steps of preparing the composite sol are as follows: dissolving yttrium nitrate in anhydrous ethanol, adding gluconic acid and triethanolamine to obtain a first solution; adding ethyl orthosilicate to the anhydrous ethanol, stirring evenly, adjusting the pH to 2.2-2.4, stirring at 40-45° C. for 27-32 minutes, to obtain a second solution; adding the first solution to the second solution, stirring at 60-65° C. for 2.2-2.8 hours, to obtain a composite glue solution; The steps of preparing the boron nitride particle / zirconia fiber composite are as follows: placing acid-treated boron nitride particles in N,N-dimethylformamide, adding thionyl chloride, and reacting under reflux at 116-123° C. for 7.8-8.2 hours, then adding p-phenylenediamine and glycine, reacting at 92-97° C. for 10-13 hours, adding modified zirconia fiber, and stirring at 58-62° C. for 36-45 minutes to obtain the boron nitride particle / zirconia fiber composite; The preparation method of the modified zirconia fiber comprises the following steps: adding aluminum nitrate to anhydrous ethanol, adding N-octanoyl-N-methylglucamine and polyvinylpyrrolidone, and stirring evenly to obtain an aluminum nitrate solution; adding zirconia fiber to the aluminum nitrate solution, allowing the solution to stand at 55-58° C. for 1.4-1.6 hours, and calcining to obtain the modified zirconia fiber.

2. The method for preparing a high-strength thermal insulation tile composite material according to claim 1, characterized in that: The boron nitride nanowire pretreatment step comprises subjecting the boron nitride nanowire to plasma treatment in an oxygen atmosphere at a power of 95-106 W for a treatment time of 4-6 minutes, to obtain plasma-treated boron nitride nanowires after the treatment. The boron nitride nanowire has a length of 4.5-4.8 μm and a diameter of 12-18 nm.

3. The method for preparing a high-strength thermal insulation tile composite material according to claim 1, characterized in that: In the step of preparing the composite sol, in the solution 1, the mass volume ratio of yttrium nitrate, anhydrous ethanol, gluconic acid and triethanolamine is 6.8-7.2g:100mL:1.0-1.4g:0.5-0.8g; The mass volume ratio of the ethyl orthosilicate and anhydrous ethanol is 3.8-4.2 g:100 mL; The volume ratio of the second solution to the first solution is 48-53:50-55.

4. The method for preparing a high-strength thermal insulation tile composite material according to claim 1, characterized in that: The impregnation step comprises: placing the plasma-treated boron nitride nanowires into the composite glue solution, performing ultrasonic dispersion, wherein the ultrasonic time is 36-45 minutes, the ultrasonic power is 130-150W, and the ultrasonic frequency is 30-35kHz. After the ultrasonic treatment, the solution is allowed to stand for 17-22 hours, and then dried at -28 to -22°C for 10-14 hours, and then dried at -47 to -42°C for 10-14 hours. After the drying is completed, the solution is naturally restored to room temperature, placed in a muffle furnace, and the temperature is increased to 800-815°C at a rate of 2.5-3.5°C / min, kept warm for 2.0-2.5 hours, and cooled to room temperature with the furnace to obtain modified boron nitride nanowires; The mass ratio of the plasma-treated boron nitride nanowires to the composite glue is 9.5-10.6:

100.

5. The method for preparing a high-strength thermal insulation tile composite material according to claim 1, characterized in that: The mass ratio of the acid-treated boron nitride particles, N,N-dimethylformamide, thionyl chloride, p-phenylenediamine, glycine, and modified zirconia fibers is 13.0-14.0:110-130:190-210:1.1-1.4:1.3-1.7:2.8-3.

2.

6. The method for preparing a high-strength thermal insulation tile composite material according to claim 1, characterized in that: The preparation method of the acid-treated boron nitride particles comprises placing the boron nitride particles in a mixed acid solution and subjecting them to ball milling treatment, wherein the ball milling time is 110-130 minutes, the ball milling speed is 200-220 rpm, the ball-to-material ratio is 2-4:1, the grinding balls are zirconia balls, and the ball milling temperature is 60-65° C. After the ball milling is completed, the solid matter is filtered out, washed, and dried to obtain the acid-treated boron nitride particles; The particle size of the boron nitride particles is 60-80 nm; The mixed acid solution is a mixture of concentrated nitric acid and concentrated sulfuric acid, wherein the volume ratio of the concentrated nitric acid to the concentrated sulfuric acid is 1:2.8-3.2; the mass concentration of the concentrated nitric acid is 66-70%, and the mass concentration of the concentrated sulfuric acid is 85-88%; The mass ratio of the boron nitride particles to the mixed acid solution is 12.0-13.0:

120.

7. The method for preparing a high-strength thermal insulation tile composite material according to claim 1, characterized in that: In the preparation method of the modified zirconia fiber, the calcination is to increase the temperature to 600-620°C at a rate of 4.0-6.0°C / min and keep the temperature for 1.0-1.4h; The length of the zirconia fiber is 8.0-9.0 μm and the diameter is 15-25 nm; The mass ratio of the aluminum nitrate, anhydrous ethanol, N-octanoyl-N-methylglucamine and polyvinylpyrrolidone is 8.0-8.5:100:0.6-0.8:0.8-1.2; The mass ratio of the zirconia fiber to the aluminum nitrate solution is 8-12:106-115.

8. The method for preparing a high-strength thermal insulation tile composite material according to claim 1, characterized in that: The molding step comprises: mixing modified boron nitride nanowires, a boron nitride particle / zirconium oxide fiber composite with an ethanol solution, adding ammonium polyacrylate and stirring evenly, adding kH792 and isopropyl tri(dioctyl pyrophosphate) titanate, stirring and reacting at 54-57° C. for 0.8-1.2 hours to obtain a molding slurry; placing the molding slurry into a mold, and performing filter pressing to obtain a molding body; The mass ratio of the modified boron nitride nanowires, boron nitride particles / zirconium oxide fiber composite, ethanol solution, ammonium polyacrylate, kH792 and isopropyl tris(dioctyl pyrophosphate) titanate is 3.0-3.5:16.5-17.0:100:1.0-1.4:0.8-1.2:0.8-1.1; The mass concentration of the ethanol solution is 23-27%.

9. The method for preparing a high-strength thermal insulation tile composite material according to claim 1, characterized in that: The calcining step comprises placing the formed green body in a calcining furnace, raising the temperature to 750-800° C. at a rate of 2.5-3.5° C. / min, keeping the temperature for 20-30 minutes, then raising the temperature to 1300-1330° C. at a rate of 1.5-2.5° C. / min, keeping the temperature for 2.0-2.5 hours, and cooling the green body to room temperature to obtain the thermal insulation tile composite material.

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