Preparation method of high-strength heat-insulating tile composite material

Abstract

The application provides a preparation method of high-strength heat-insulating tile composite material, and belongs to the technical field of heat-insulating tile composite material; the preparation method comprises the steps of boron nitride nanowire modification, preparation of boron nitride particle / zirconium oxide fiber composite, molding and calcination; the preparation of composite sol step is that yttrium nitrate is dissolved in anhydrous ethanol, glucose acid and triethanolamine are added, and solution one is obtained; tetraethyl orthosilicate is added to anhydrous ethanol, uniformly stirred, the pH is adjusted to 2.2-2.4, and 40-45 DEG C stirring is carried out for 27-32 min to obtain solution two; solution one is added to solution two, 60-65 DEG C stirring is carried out for 2.2-2.8 h, and the composite glue solution is obtained; the heat-insulating tile composite material prepared by the method has high strength, good heat-insulating performance and excellent high-temperature stability.

Description

TECHNICAL FIELD

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

[0002] The thermal insulation tile is a material with high-efficiency thermal insulation performance, which is usually made of ceramics, carbon fibers or other special materials; when an aircraft flies at a high speed in the atmosphere, it will rub against the air violently to generate extremely high temperature; the thermal insulation tile, as an important component of the protection system on the surface of the aircraft, can insulate high temperature when the aircraft flies at a high speed or reenters the atmosphere, can effectively block the heat from entering the inside of the aircraft, and can protect the structure and internal equipment of the aircraft from high temperature damage to ensure the safe operation of the aircraft.

[0003] With the continuous improvement of the flight speed of the aircraft and the increasingly strict flight performance requirements, the strength of the thermal insulation tile is required to be improved, the high-strength thermal insulation tile can not only better bear the aerodynamic load and mechanical stress in the flight process, but also can guarantee the structural stability performance in the high-temperature environment, avoid damage and shedding due to insufficient strength, and thus can improve the safety and reliability of the aircraft.

[0004] At present, the preparation method of the high-strength thermal insulation tile composite material mainly adopts the fiber reinforcement method, that is, quartz fibers, carbon fibers and other fiber reinforcements are added to the matrix material to improve the strength, but the interface bonding performance between the fibers and the matrix is poor, and there is a problem of uneven dispersion between the fibers and the matrix, which can easily lead to local over-high or over-low strength of the thermal insulation tile composite material, affecting the overall performance of the composite material.

[0005] CN118851783A discloses a high-strength and low-thermal-conductivity ceramic fiber cotton-based thermal insulation tile and a preparation method thereof, specifically discloses that a high-temperature binder and soluble starch are mixed to obtain a mixed powder, the mixed powder is dispersed into anhydrous ethanol, stirred uniformly to obtain a mixed liquid; a dispersant is dispersed into high-purity water, stirred uniformly to obtain a solvent; the mixed liquid and the ceramic fiber cotton are added into the solvent, stirred and dispersed uniformly to obtain a mixed slurry; the mixed slurry is poured into a mold, vacuum filtration is performed, a wet blank is obtained; the wet blank is dried and sintered to obtain the ceramic fiber cotton-based thermal insulation tile.

[0006] The patent adds a dispersant in the solvent, which is beneficial to the dispersion of the fiber cotton, and the obtained thermal insulation tile material has a room temperature compression strength of 3.9MPa and an average linear expansion coefficient of 0.32x10 -6 / ℃(RT~700℃);

[0007] The obtained heat insulation tile material improves the compression strength and reduces the linear expansion coefficient to a certain extent, but the strength rapidly decreases above 1000 DEG C, which affects the use in super high temperature environment.

[0008] In addition, the technical personnel also found in the development process that the heat insulation tile composite material is prone to cracks in the high temperature environment of rapid heating, thereby damaging the overall structure, reducing the mechanical properties, and ultimately shortening the service life of the heat insulation tile composite material. SUMMARY

[0009] In order to solve the technical problems existing in the prior art, the application provides a preparation method of high-strength heat insulation tile composite material, which improves the strength performance, still has high strength above 1000 DEG C, and ensures excellent stability in the high temperature environment of rapid heating.

[0010] In view of the above technical problems, the application adopts the following technical solutions:

[0011] The preparation method of the high-strength heat insulation tile composite material comprises the steps of boron nitride nanowire modification, preparation of boron nitride particle / zirconium oxide fiber composite, molding and calcination, and the specific operation is as follows:

[0012] 1. Boron nitride nanowire modification

[0013] (1) Pretreatment of boron nitride nanowire

[0014] The boron nitride nanowire is subjected to plasma treatment, the treatment atmosphere is oxygen, the treatment power is 95-106 W, the treatment time is 4-6 min, and the plasma treated boron nitride nanowire is obtained after the treatment is completed;

[0015] The length of the boron nitride nanowire is 4.5-4.8 mu m, and the diameter is 12-18 nm;

[0016] (2) Preparation of composite sol

[0017] Dissolve yttrium nitrate in anhydrous ethanol, after complete dissolution, add glucose acid and triethanolamine, increase the temperature to 57-62 DEG C, stir at 210-230 rpm for 0.8-1.2 h, obtain solution one; add tetraethyl orthosilicate to anhydrous ethanol, after uniform stirring, add 23-27 wt% nitric acid solution to adjust the pH to 2.2-2.4, stir at 40-45 DEG C for 27-32 min, obtain solution two; slowly add solution one to solution two, control the addition rate to be 0.8-1.2 mL / min, increase the temperature at the same time, control the temperature increasing rate to be 2.5-3.5 DEG C / min, increase the temperature to 60-65 DEG C, stop increasing the temperature, after the addition is completed, heat and stir at 60-65 DEG C for 2.2-2.8 h, obtain the composite sol;

[0018] The mass-volume ratio of yttrium nitrate, anhydrous ethanol, glucose acid and triethanolamine in the solution one is 6.8-7.2g:100mL:1.0-1.4g:0.5-0.8g;

[0019] The mass-volume ratio of tetraethyl orthosilicate, anhydrous ethanol is 3.8-4.2g:100mL;

[0020] The volume ratio of the solution two, the solution one is 48-53:50-55;

[0021] (3) Immersion

[0022] The plasma treated boron nitride nanowires are put into the composite glue solution, ultrasonic dispersion is carried out, the ultrasonic time is 36-45min, the ultrasonic power is 130-150W, the ultrasonic frequency is 30-35kHz, after the ultrasonic treatment is finished, 17-22h is placed, then it is dried at-28~-22℃ for 10-14h, it is dried at-47~-42℃ for 10-14h, after the drying is finished, it is naturally recovered to room temperature, it is put into a muffle furnace, the temperature is increased to 800-815℃ at a rate of 2.5-3.5℃ / min, it is kept warm for 2.0-2.5h, it is cooled to room temperature along with the furnace, modified boron nitride nanowires are obtained;

[0023] The mass ratio of the plasma treated boron nitride nanowires, the composite glue solution is 9.5-10.6:100.

[0024] 2. Preparation of boron nitride particle / zirconia fiber composite

[0025] The aluminum nitrate is put into anhydrous ethanol, N-octanoyl-N-methyl glucosamine and polyvinylpyrrolidone are added, after stirring uniformly, an aluminum nitrate solution is obtained; the zirconia fiber is put into the aluminum nitrate solution, the temperature is increased to 55-58℃, it is kept warm and placed for 1.4-1.6h, after the placement is finished, the solid is filtered out, after washing and drying, it is put into a calcining furnace, the temperature is increased to 600-620℃ at a rate of 4.0-6.0℃ / min, it is kept warm and calcined for 1.0-1.4h, modified zirconia fiber is obtained;

[0026] The length of the zirconia fiber is 8.0-9.0μm, the diameter is 15-25nm;

[0027] The mass ratio of the aluminum nitrate, anhydrous ethanol, N-octanoyl-N-methyl glucosamine and polyvinylpyrrolidone is 8.0-8.5:100:0.6-0.8:0.8-1.2;

[0028] The mass ratio of the zirconia fiber, the aluminum nitrate solution is 8-12:106-115;

[0029] Put the boron nitride particles into the mixed acid solution for ball milling treatment, the ball milling time is 110-130 min, the ball milling speed is 200-220 rpm, the ball to material ratio is 2-4:1, the milling ball is zirconium oxide ball, the ball milling temperature is 60-65℃, after ball milling, filter out the solid, wash and dry to obtain the acid treated boron nitride particles; put the acid treated boron nitride particles into N,N-dimethylformamide, stir uniformly, then add sulfoxide chloride, increase the temperature to 116-123℃ at a rate of 1.8-2.2℃ / min, reflux for 7.8-8.2h, then add p-phenylenediamine and glycine, keep the temperature at 92-97℃ for 10-13h, after the reaction, add modified zirconium oxide fiber, keep the temperature at 58-62℃ for 36-45min, the stirring speed is 240-260rpm, after stirring, filter, wash and dry to obtain the boron nitride particle / zirconium oxide fiber composite;

[0030] The particle size of the boron nitride particles is 60-80nm;

[0031] The mixed acid solution is a mixture of concentrated nitric acid and concentrated sulfuric acid, the volume ratio of the concentrated nitric acid and the concentrated sulfuric acid is 1:2.8-3.2, the mass concentration of the concentrated nitric acid is 66-70%, the mass concentration of the concentrated sulfuric acid is 85-88%;

[0032] The mass ratio of the boron nitride particles and the mixed acid solution is 12.0-13.0:120;

[0033] The mass ratio of the acid treated boron nitride particles, N,N-dimethylformamide, sulfoxide chloride, p-phenylenediamine, glycine and modified zirconium oxide fiber is 13.0-14.0:110-130:190-210:1.1-1.4:1.3-1.7:2.8-3.2.

[0034] 3. Shaping

[0035] Mix the modified boron nitride nanowire and the boron nitride particle / zirconium oxide fiber composite with ethanol solution, add ammonium polyacrylate, stir uniformly, then add kH792 and isopropyl tri(dioctyl pyrophosphoryloxy) titanate, stir at 54-57℃ for 0.8-1.2h to obtain a shaping slurry; put the shaping slurry into a mold, press filter to shape to obtain a shaped body;

[0036] The mass ratio of the modified boron nitride nanowire, the boron nitride particle / zirconium oxide fiber composite, ethanol solution, ammonium polyacrylate, kH792 and isopropyl tri(dioctyl pyrophosphoryloxy) titanate is 3.0-3.5:16.5-17.0:100:1.0-1.4:0.8-1.2:0.8-1.1;

[0037] The mass concentration of the ethanol solution is 23-27%.

[0038] 4. Calcining

[0039] The shaped blank is placed in a calcining furnace, the temperature is raised to 750-800 DEG C at a rate of 2.5-3.5 DEG C / min, and then the temperature is raised to 1300-1330 DEG C at a rate of 1.5-2.5 DEG C / min, and the temperature is kept for 2.0-2.5 h, and the furnace is cooled to room temperature, and a heat insulation tile composite material is obtained.

[0040] Compared with the prior art, the present application has the following beneficial effects:

[0041] 1. The heat insulation tile composite material prepared by the present application uses boron nitride particles and zirconium oxide fibers as a matrix, and boron nitride nanowires as a reinforcing body. The boron nitride nanowires have good high-temperature resistance, low thermal conductivity, good heat insulation performance, and can hinder crack propagation. Specifically, the boron nitride nanowires are first subjected to oxygen plasma treatment. High-energy particles bombard the surface of the boron nitride nanowires, causing an oxidation reaction, thereby introducing hydroxyl and carboxyl oxygen-containing functional groups on the surface of the boron nitride nanowires, improving the surface activity. Then, the boron nitride nanowires are treated with a composite sol. The composite sol is prepared by compounding yttrium oxide sol and silicon dioxide sol. During the sol mixing process, Y 3+The hydroxyl groups on the surface of the silica sol will react with the yttrium oxide to form Y-O-Si bonds, thereby generating a yttrium oxide-silica composite sol, forming a stable sol network structure, which, after impregnation of the boron nitride nanowires treated by oxygen plasma, will form a yttrium oxide-silica ceramic phase, bonding the boron nitride nanowires together, thereby obtaining a porous framework structure to provide strength support for the heat insulation tile composite and improve its mechanical properties, heat insulation performance and high temperature resistance; in the preparation step of the boron nitride particle / zirconia fiber composite, an aluminum oxide coating is first coated on the surface of the zirconia fiber to improve the toughness and high temperature resistance of the fiber and improve the compatibility between the boron nitride particles, then the boron nitride particles are subjected to carboxyl group treatment, acyl chloride groups are introduced by using thionyl chloride, then amino compounds such as p-phenylenediamine and glycine are added, which are subjected to amidation reaction with the acyl chloride groups, and the amino groups can be combined with the aluminum oxide on the surface of the zirconia fiber, thereby enhancing the bonding force between the boron nitride particles and the zirconia fiber and forming a three-dimensional network structure to enhance the strength performance and stability of the heat insulation tile composite; in the forming step, the ammonium polyacrylate as a dispersant and the coupling agent as an interfacial compatibilizer can improve the bonding between the zirconia fiber, the boron nitride nanowire and the boron nitride particle, and enhance the compatibility with the ammonium polyacrylate, thereby obtaining a formed slurry with good homogeneity; the specific composition and specific method used in the present application can finally improve the strength performance and heat insulation performance of the heat insulation tile composite, and improve the strength retention rate at high temperature, avoid cracks during use in a high temperature environment, and ensure the stability of the composite material.

[0042] 2. The high-strength heat insulation tile composite prepared by the preparation method of the present application has a thermal conductivity of 0.033-0.037 W / (m·K), a fracture toughness of 1.51-1.57 MPa·m 1 / 2 , a compressive strength of 5.48-5.56 MPa, a bending strength of 2.42-2.48 MPa, and a compressive strength of 6.35-6.41 MPa.

[0043] 3. The high-strength heat insulation tile composite prepared by the preparation method of the present application has a fracture toughness of 1.44-1.52 MPa·m 1 / 2 , a compressive strength of 5.21-5.35 MPa, a bending strength of 2.30-2.39 MPa, and a compressive strength of 5.98-6.13 MPa when the temperature is increased to 1300℃ at a rate of 5.0℃ / min and kept for 10d.

[0044] 4. The high-strength thermal insulation tile composite material prepared by the preparation method of the application is heated at a rate of 60 ℃ / min to 1000 ℃, kept for 120 h, then heated at a rate of 50 ℃ / min to 1300 ℃, kept for 120 h, and the fracture toughness is 1.42-1.49 MPa·m, the compressive strength is 5.13-5.25 MPa, the bending strength is 2.27-2.35 MPa, and the compressive strength is 5.92-6.01 MPa. 1 / 2 , the compressive strength is 5.13-5.25 MPa, the bending strength is 2.27-2.35 MPa, and the compressive strength is 5.92-6.01 MPa. DETAILED DESCRIPTION

[0045] In order to more clearly understand the technical features, objectives and effects of the application, the specific embodiments of the application will be described.

[0046] Example 1

[0047] 1. Modification of boron nitride nanowires

[0048] (1) Pretreatment of boron nitride nanowires

[0049] The boron nitride nanowires are subjected to plasma treatment, the treatment atmosphere is oxygen, the treatment power is 106 W, the treatment time is 4 min, and the plasma-treated boron nitride nanowires are obtained after the treatment is completed;

[0050] The length of the boron nitride nanowires is 4.8 μm, and the diameter is 18 nm;

[0051] (2) Preparation of composite sol

[0052] 7.2 g of yttrium nitrate is dissolved in 100 mL of anhydrous ethanol, after complete dissolution, 1.4 g of gluconic acid and 0.8 g of triethanolamine are added, the temperature is raised to 62 ℃, and stirring is carried out at 230 rpm for 0.8 h to obtain solution one; 4.2 g of tetraethyl orthosilicate is added to 100 mL of anhydrous ethanol, after uniform stirring, 27 wt% nitric acid solution is added to adjust the pH to 2.4, and stirring is carried out at 45 ℃ for 32 min to obtain solution two; 55 mL of solution one is slowly added to 53 mL of solution two, the addition rate is controlled at 1.2 mL / min, the temperature is raised at the same time, the temperature raising rate is controlled at 3.5 ℃ / min, the temperature is raised to 65 ℃, the temperature raising is stopped, and after the addition is completed, the temperature is kept at 65 ℃ and stirring is carried out for 2.2 h to obtain a composite sol;

[0053] (3) Impregnation

[0054] Put 10.6 g of plasma treated boron nitride nanowires into 100 g of composite glue solution, ultrasonic dispersion, ultrasonic time is 45 min, ultrasonic power is 150 W, ultrasonic frequency is 35 kHz, after ultrasonic treatment, stand for 22 h, then dry at-22℃ for 14 h, dry at-42℃ for 14 h, after drying, wait for natural recovery to room temperature, put into the muffle furnace, increase the temperature to 815℃ at a rate of 3.5℃ / min, keep warm for 2.0 h, cool down to room temperature with the furnace, get modified boron nitride nanowires.

[0055] 2. Preparation of boron nitride particle / zirconia fiber composite

[0056] Put 8.5 g of aluminum nitrate into 100 g of anhydrous ethanol, add 0.8 g of N-octanoyl-N-methyl glucosamine and 1.2 g of polyvinylpyrrolidone, after stirring uniformly, get aluminum nitrate solution; Put 12 g of zirconia fiber into 115 g of aluminum nitrate solution, increase the temperature to 58℃, keep warm for 1.6 h, after standing, filter out the solid, after washing and drying, put into the calcining furnace, increase the temperature to 620℃ at a rate of 6.0℃ / min, keep warm and calcine for 1.0 h, get modified zirconia fiber;

[0057] The length of the zirconia fiber is 9.0 μm, and the diameter is 25 nm;

[0058] Put 13.0 g of boron nitride particles into 120 g of mixed acid solution for ball milling, ball milling time is 130 min, ball milling speed is 220 rpm, ball to material ratio is 4:1, milling ball is zirconia ball, ball milling temperature is 65℃, after ball milling, filter out the solid, wash and dry, get acid treated boron nitride particles; Put 14.0 g of acid treated boron nitride particles into 130 g of N,N-dimethylformamide, stir uniformly, then add 210 g of thionyl chloride, increase the temperature to 123℃ at a rate of 2.2℃ / min, reflux for 8.2 h, then add 1.4 g of p-phenylenediamine, 1.7 g of glycine, keep warm at 97℃ for 10 h, after reaction, add 3.2 g of modified zirconia fiber, keep warm at 62℃ for 36 min, stirring speed is 260 rpm, after stirring, filter, wash and dry, get boron nitride particle / zirconia fiber composite;

[0059] The particle size of the boron nitride particle is 80 nm;

[0060] The mixed acid solution is a mixed solution of concentrated nitric acid and concentrated sulfuric acid, the volume ratio of the concentrated nitric acid and 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%.

[0061] 3. Shaping

[0062] Mix 3.5 g of modified boron nitride nanowires, 17.0 g of boron nitride particle / zirconia fiber composite, and 100 g of a 27 wt% ethanol solution, add 1.4 g of ammonium polyacrylate, stir until uniform, then add 1.2 g of kH792 and 1.1 g of isopropyl tri(dioctyl pyrophosphato) titanate, stir at 57°C for 0.8 h to obtain a molding slurry; place the molding slurry into a mold, and press filter to form a molding body.

[0063] 4. Calcination

[0064] Place the molding body in a calcination furnace, increase the temperature to 800°C at a rate of 3.5°C / min, maintain for 20 min, then increase the temperature to 1330°C at a rate of 2.5°C / min, maintain for 2.0 h, cool to room temperature with the furnace, and obtain an insulation tile composite.

[0065] Example 2

[0066] 1. Modification of boron nitride nanowires

[0067] (1) Pretreatment of boron nitride nanowires

[0068] The boron nitride nanowires are subjected to plasma treatment, the treatment atmosphere is oxygen, the treatment power is 95 W, and the treatment time is 6 min; after the treatment, plasma-treated boron nitride nanowires are obtained;

[0069] The length of the boron nitride nanowires is 4.5 μm, and the diameter is 12 nm;

[0070] (2) Preparation of a composite sol

[0071] Dissolve 6.8 g of yttrium nitrate in 100 mL of anhydrous ethanol, after complete dissolution, add 1.0 g of gluconic acid and 0.5 g of triethanolamine, increase the temperature to 57°C, and stir at 210 rpm for 1.2 h to obtain solution one; add 3.8 g of tetraethyl orthosilicate to 100 mL of anhydrous ethanol, stir until uniform, then add a 23 wt% nitric acid solution to adjust the pH to 2.2, stir at 40°C for 27 min to obtain solution two; slowly add 50 mL of solution one to 48 mL of solution two, control the addition rate to be 0.8 mL / min, add while controlling the temperature increase rate to be 2.5°C / min, increase the temperature to 60°C, stop increasing the temperature, after the addition is completed, maintain the temperature at 60°C and stir for 2.8 h to obtain a composite sol;

[0072] (3) Impregnation

[0073] Put 9.5 g of plasma treated boron nitride nanowires into 100 g of composite glue solution, ultrasonic dispersion, ultrasonic time is 36 min, ultrasonic power is 130 W, ultrasonic frequency is 30 kHz, after ultrasonic treatment, stand for 17 h, then dry at-28℃ for 10 h, dry at-47℃ for 10 h, after drying, wait for natural recovery to room temperature, put into the muffle furnace, increase the temperature to 800℃ at a rate of 2.5℃ / min, keep warm for 2.5 h, cool down to room temperature with the furnace, get modified boron nitride nanowires.

[0074] 2. Preparation of boron nitride particle / zirconia fiber composite

[0075] Put 8.0 g of aluminum nitrate into 100 g of anhydrous ethanol, add 0.6 g of N-octanoyl-N-methyl glucosamine and 0.8 g of polyvinylpyrrolidone, stir uniformly to get aluminum nitrate solution; put 8 g of zirconia fiber into 106 g of aluminum nitrate solution, increase the temperature to 55℃, keep warm for 1.4 h, after standing, filter out the solid, wash and dry, put into the calcining furnace, increase the temperature to 600℃ at a rate of 4.0℃ / min, keep warm and calcine for 1.4 h, get modified zirconia fiber;

[0076] The length of the zirconia fiber is 8.0 μm, and the diameter is 15 nm;

[0077] Put 12.0 g of boron nitride particles into 120 g of mixed acid solution for ball milling, ball milling time is 110 min, ball milling speed is 200 rpm, ball to material ratio is 2:1, milling ball is zirconia ball, ball milling temperature is 60℃, after ball milling, filter out the solid, wash and dry to get acid treated boron nitride particles; put 13.0 g of acid treated boron nitride particles into 110 g of N,N-dimethylformamide, stir uniformly, then add 190 g of thionyl chloride, increase the temperature to 116℃ at a rate of 1.8℃ / min, reflux for 7.8 h, then add 1.1 g of p-phenylenediamine, 1.3 g of glycine, keep warm at 92℃ for 13 h, after reaction, add 2.8 g of modified zirconia fiber, keep warm at 58℃ for 45 min with stirring at a speed of 240 rpm, after stirring, filter, wash and dry to get boron nitride particle / zirconia fiber composite;

[0078] The particle size of the boron nitride particle is 60 nm;

[0079] The mixed acid solution is a mixture of concentrated nitric acid and concentrated sulfuric acid, the volume ratio of the concentrated nitric acid and 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%.

[0080] 3. Shaping

[0081] Mix 3.0 g of modified boron nitride nanowires, 16.5 g of boron nitride particle / zirconia fiber composite, and 100 g of a 23 wt% ethanol solution, add 1.0 g of ammonium polyacrylate, stir until uniform, then add 0.8 g of kH792 and 0.8 g of isopropyl tri(dioctyl pyrophosphato) titanate, stir at 54°C for 1.2 h to obtain a molding slurry; place the molding slurry into a mold, and press filter to form a molding body.

[0082] 4. Calcination

[0083] Place the molding body in a calcination furnace, increase the temperature to 750°C at a rate of 2.5°C / min, maintain for 30 min, then increase the temperature to 1300°C at a rate of 1.5°C / min, maintain for 2.5 h, cool to room temperature with the furnace, and obtain an insulation tile composite.

[0084] Example 3

[0085] 1. Modification of boron nitride nanowires

[0086] (1) Pretreatment of boron nitride nanowires

[0087] The boron nitride nanowires are subjected to plasma treatment, the treatment atmosphere is oxygen, the treatment power is 100 W, and the treatment time is 5 min, and the plasma-treated boron nitride nanowires are obtained after the treatment is completed;

[0088] The length of the boron nitride nanowires is 5.0 μm, and the diameter is 15 nm;

[0089] (2) Preparation of composite sol

[0090] Dissolve 7.1 g of yttrium nitrate in 100 mL of anhydrous ethanol, after complete dissolution, add 1.2 g of gluconic acid and 0.7 g of triethanolamine, increase the temperature to 60°C, and stir at 220 rpm for 1.0 h to obtain solution one; add 4.0 g of tetraethyl orthosilicate to 100 mL of anhydrous ethanol, stir until uniform, then add a 25 wt% nitric acid solution to adjust the pH to 2.3, stir at 42°C for 30 min to obtain solution two; slowly add 52 mL of solution one to 50 mL of solution two, control the addition rate to be 1.0 mL / min, add while controlling the heating rate to be 3.0°C / min, and stop heating when the temperature reaches 63°C, after the addition is completed, stir at 63°C for 2.5 h to obtain a composite sol;

[0091] (3) Impregnation

[0092] Put 10 g of the plasma-treated boron nitride nanowires into 100 g of the composite glue solution, and perform ultrasonic dispersion, with an ultrasonic time of 40 min, an ultrasonic power of 140 W, and an ultrasonic frequency of 32 kHz. After the ultrasonic treatment, stand for 20 h, and then dry at -25℃ for 12 h and at -45℃ for 12 h. After the drying, wait for natural recovery to room temperature, put into a muffle furnace, increase the temperature to 810℃ at a rate of 3.0℃ / min, and keep the temperature for 2.3 h. Cool down to room temperature with the furnace, and obtain the modified boron nitride nanowires.

[0093] 2. Preparation of boron nitride particle / zirconia fiber composite

[0094] Put 8.3 g of aluminum nitrate into 100 g of anhydrous ethanol, add 0.7 g of N-octanoyl-N-methyl glucosamine and 1.0 g of polyvinylpyrrolidone, stir uniformly, and obtain an aluminum nitrate solution. Put 10 g of zirconia fiber into 110 g of the aluminum nitrate solution, increase the temperature to 56℃, and stand for 1.5 h. After the standing, filter out the solid, wash and dry, put into a calcination furnace, increase the temperature to 610℃ at a rate of 5.0℃ / min, and keep the temperature for 1.2 h of calcination. Obtain the modified zirconia fiber.

[0095] The length of the zirconia fiber is 8.5 μm, and the diameter is 20 nm.

[0096] Put 12.5 g of boron nitride particles into 120 g of mixed acid solution for ball milling, with a ball milling time of 120 min, a ball milling rotation speed of 210 rpm, a ball-to-material ratio of 3:1, zirconia balls as the milling balls, and a ball milling temperature of 63℃. After the ball milling, filter out the solid, wash and dry, and obtain the acid-treated boron nitride particles. Put 13.5 g of the acid-treated boron nitride particles into 120 g of N,N-dimethylformamide, stir uniformly, add 200 g of thionyl chloride, increase the temperature to 120℃ at a rate of 2.0℃ / min, and reflux for 8.0 h. Then add 1.3 g of p-phenylenediamine and 1.5 g of glycine, keep the temperature at 95℃ for 12 h of reaction. After the reaction, add 3.0 g of the modified zirconia fiber, keep the temperature at 60℃ for 40 min of stirring, with a stirring rotation speed of 250 rpm. After the stirring, filter, wash and dry, and obtain the boron nitride particle / zirconia fiber composite.

[0097] The particle size of the boron nitride particles is 70 nm.

[0098] The mixed acid solution is a mixed solution of concentrated nitric acid and concentrated sulfuric acid, with a volume ratio of the concentrated nitric acid to the concentrated sulfuric acid of 1:3. The mass concentration of the concentrated nitric acid is 68%, and the mass concentration of the concentrated sulfuric acid is 87%.

[0099] 3. Shaping

[0100] 3.3g of modified boron nitride nanowires, 16.7g of boron nitride particles / zirconia fiber composite were mixed with 100g of 25wt% ethanol solution. 1.2g of ammonium polyacrylate was added and stirred until homogeneous. Then, 1.0g of KH792 and 1.0g of isopropyltris(dioctylpyrophosphate)titanate were added and stirred at 55℃ for 1.0h to obtain a molding slurry. The molding slurry was placed into a mold and pressed and filtered to obtain a molded preform.

[0101] 4. Calcination

[0102] The molded preform was placed in a calcining furnace, and the temperature was increased to 780℃ at a rate of 3.0℃ / min and held for 25 min. Then the temperature was increased to 1320℃ at a rate of 2.0℃ / min and held for 2.3 h. The preform was then cooled to room temperature in the furnace to obtain the heat-insulating tile composite material.

[0103] This invention prepares a heat-insulating tile composite material using boron nitride particles and zirconium oxide fibers as the matrix and boron nitride nanowires as the reinforcement. Boron nitride nanowires possess good high-temperature resistance, low thermal conductivity, and excellent heat insulation performance, and can also 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 an oxidation reaction, thereby introducing hydroxyl and carboxyl oxygen-containing functional groups onto the surface of the boron nitride nanowires, improving surface activity. Then, a composite sol is used for further treatment. The composite sol is prepared by combining yttrium oxide sol and silica sol. During the sol mixing process, Y... 3+It reacts with the hydroxyl groups on the surface of silica sol to form YO-Si bonds, thereby generating a yttrium oxide-silica composite sol and forming a stable sol network structure. After impregnation with oxygen plasma-treated boron nitride nanowires, it forms a yttrium oxide-silica ceramic phase, which bonds the boron nitride nanowires together, resulting in a porous framework structure. This provides strength support for the heat insulation tile composite material, improving its mechanical properties, heat insulation properties, and high-temperature resistance. In the preparation steps of the boron nitride particle / zirconia fiber composite, an alumina coating is first applied to the surface of the zirconia fiber to improve the fiber's toughness and high-temperature resistance, and to improve its compatibility with the boron nitride particles. Then, the boron nitride particles are carboxylated by introducing acyl chloride groups through thionyl chloride, followed by the addition of amino compounds such as p-phenylenediamine and glycine. The boron nitride nanowires react with acyl chloride groups to form an amidation reaction, and the amino groups can combine with the alumina on the surface of the zirconia fibers, ultimately enhancing the bonding force between the boron nitride particles and the zirconia fibers, forming a three-dimensional network structure. This enhances the strength and stability of the thermal insulation tile composite material. In the molding step, ammonium polyacrylate acts as a dispersant, and the coupling agent acts as an interfacial compatibilizer, improving the bonding between the zirconia fibers, boron nitride nanowires, and boron nitride particles, and enhancing the compatibility with ammonium polyacrylate, thus obtaining a homogeneous molding slurry. This invention uses specific components and methods to ultimately improve the strength and thermal insulation performance of the thermal insulation tile composite material, and improves the strength retention rate at high temperatures, avoiding cracks during use in high-temperature environments and ensuring the stability of the composite material.

[0104] Comparative Example 1

[0105] Based on Example 3, the following changes were made:

[0106] (1) In the impregnation step of boron nitride nanowire modification, the composite adhesive is replaced with solution two in equal amount; the preparation method of solution two is to add 4.0g of tetraethyl orthosilicate to 100mL of anhydrous ethanol, stir evenly, add 25wt% nitric acid solution to adjust the pH to 2.3, stir at 42℃ for 30min to obtain solution two;

[0107] (2) In the molding step, the operation step of “adding 1.0g kH792 and 1.0g isopropyl tris(dioctyl pyrophosphoryloxy) titanate and stirring at 55°C for 1.0h” is omitted;

[0108] All other operations remain unchanged.

[0109] Comparative Example 1 only uses silicon dioxide to treat boron nitride nanowires, which reduces the strength of the composite material and its high-temperature stability. Furthermore, Comparative Example 1 omits the coupling agent in the molding process, resulting in weak interfacial bonding between the components and uneven molding slurry, ultimately reducing the strength, toughness, and high-temperature stability of the composite material.

[0110] Comparative Example 2

[0111] Based on Example 3, the following changes were made:

[0112] The steps for preparing the boron nitride particle / zirconia fiber composite are as follows: 12.5g of boron nitride particles are placed in 120g of mixed acid solution and ball-milled for 120min at a speed of 210rpm, with a ball-to-material ratio of 3:1. Zirconia balls are used as the grinding balls, and the ball-milling temperature is 63℃. After ball milling, the solid is filtered out, washed, and dried to obtain acid-treated boron nitride particles. 13.5g of acid-treated boron nitride particles are placed in 120g of N,N-dimethylformamide and stirred evenly. Then, 3.0g of untreated zirconia fiber is added, and the mixture is kept at 60℃ and stirred for 40min at a speed of 250rpm. After stirring, the mixture is filtered, washed, and dried to obtain the boron nitride particle / zirconia fiber composite.

[0113] The boron nitride particles have a particle size of 70 nm;

[0114] The mixed acid solution is a mixture of concentrated nitric acid and concentrated sulfuric acid, with a volume ratio of 1:3; the mass concentration of the concentrated nitric acid is 68%, and the mass concentration of the concentrated sulfuric acid is 87%.

[0115] The zirconium oxide fiber has a length of 8.5 μm and a diameter of 20 nm;

[0116] All other operations remain unchanged.

[0117] In Comparative Example 2, boron nitride particles were acid-treated and then directly mixed with untreated zirconia fibers. On the one hand, no alumina layer was formed on the surface of the zirconia fibers, which would reduce the toughening effect of the zirconia fibers. On the other hand, the zirconia fibers and acid-treated boron nitride particles were only physically mixed, resulting in poor interfacial bonding, which reduced the thermal insulation performance and the strength and stability of the composite material.

[0118] Performance testing

[0119] 1. Basic performance

[0120] The heat-insulating tile composite materials prepared by the methods of Examples 1-3 and Comparative Examples 1-2 were subjected to basic performance tests at room temperature, as follows:

[0121]

[0122] 2. High temperature resistance

[0123] The heat-insulating tile composite materials prepared by the methods of Examples 1-3 and Comparative Examples 1-2 were heated to 1300℃ at a rate of 5.0℃ / min, kept at that temperature for 10 days, and their strength properties were tested again, as follows:

[0124]

[0125] 3. Rapid heating and stable performance

[0126] The heat-insulating tile composite materials prepared by the methods of Examples 1-3 and Comparative Examples 1-2 were heated to 1000°C at a rate of 60°C / min, held at that temperature for 120 hours, and then heated to 1300°C at a rate of 50°C / min and held at that temperature for 120 hours. The strength properties were then tested again, as follows:

[0127]

[0128] Unless otherwise stated, all percentages used in this invention are mass percentages.

[0129] 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 foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a high-strength heat-insulating tile composite material, characterized in that, This includes steps such as boron nitride nanowire modification, preparation of boron nitride particle / zirconia fiber composite, molding, and calcination. The boron nitride nanowire modification includes boron nitride nanowire pretreatment, preparation of composite sol, and impregnation steps; The boron nitride nanowire pretreatment step is to subject the boron nitride nanowires to plasma treatment in an oxygen atmosphere, and obtain plasma-treated boron nitride nanowires after the treatment is completed. The steps for preparing the composite sol are as follows: dissolve yttrium nitrate in anhydrous ethanol, add gluconic acid and triethanolamine to obtain solution one; add tetraethyl orthosilicate to anhydrous ethanol, stir evenly, adjust the pH to 2.2-2.4, stir at 40-45℃ for 27-32 min to obtain solution two; add solution one to solution two, stir at 60-65℃ for 2.2-2.8 h to obtain the composite sol; The impregnation step involves adding plasma-treated boron nitride nanowires into a composite adhesive solution and ultrasonically dispersing them. After ultrasonic treatment, the nanowires are allowed to stand for 17-22 hours, then dried at -28 to -22°C for 10-14 hours and at -47 to -42°C for 10-14 hours. After drying, the nanowires are allowed to naturally return to room temperature and then placed in a muffle furnace. The temperature is increased to 800-815°C at a rate of 2.5-3.5°C / min and held for 2.0-2.5 hours. The nanowires are then cooled to room temperature in the furnace to obtain modified boron nitride nanowires. The steps for preparing the boron nitride particle / zirconia fiber composite are as follows: acid-treated boron nitride particles are placed in N,N-dimethylformamide, thionyl chloride is added, and the mixture is refluxed at 116-123℃ for 7.8-8.2 h. Then, p-phenylenediamine and glycine are added, and the mixture is reacted at 92-97℃ for 10-13 h. Modified zirconia fibers are added, and the mixture is stirred at 58-62℃ for 36-45 min to obtain the boron nitride particle / zirconia fiber composite. The modified zirconia fiber is prepared by adding aluminum nitrate to anhydrous ethanol, adding N-octanoyl-N-methylglucosamine and polyvinylpyrrolidone, stirring evenly to obtain an aluminum nitrate solution; adding zirconia fiber to the aluminum nitrate solution, letting it stand at 55-58℃ for 1.4-1.6h, and calcining to obtain modified zirconia fiber. The molding step is as follows: the modified boron nitride nanowires, boron nitride particles / zirconia fiber composites are mixed with ethanol solution, ammonium polyacrylate is added and stirred evenly, then kH792 and isopropyltris(dioctylpyrophosphoryloxy)titanate are added, and the mixture is stirred and reacted at 54-57℃ for 0.8-1.2h to obtain a molding slurry; the molding slurry is placed into a mold, pressed and filtered to obtain a molded green body.

2. The method for preparing a high-strength heat-insulating tile composite material according to claim 1, characterized in that, The boron nitride nanowire pretreatment step is to subject the boron nitride nanowires to plasma treatment in an oxygen atmosphere, with a treatment power of 95-106W and a treatment time of 4-6 minutes. After the treatment, plasma-treated boron nitride nanowires are obtained. The boron nitride nanowires have a length of 4.5-4.8 μm and a diameter of 12-18 nm.

3. The method for preparing a high-strength heat-insulating tile composite material according to claim 1, characterized in that, In the step of preparing the composite sol, the mass-to-volume ratio of yttrium nitrate, anhydrous ethanol, gluconic acid, and triethanolamine in solution one is 6.8-7.2 g: 100 mL: 1.0-1.4 g: 0.5-0.8 g; The mass-to-volume ratio of the tetraethyl orthosilicate and anhydrous ethanol is 3.8-4.2 g: 100 mL; The volume ratio of Solution 2 to Solution 1 is 48-53:50-55.

4. The method for preparing a high-strength heat-insulating tile composite material according to claim 1, characterized in that, The impregnation step involves immersing plasma-treated boron nitride nanowires into a composite adhesive solution and ultrasonically dispersing them for 36-45 minutes at a power of 130-150 W and a frequency of 30-35 kHz. After ultrasonic treatment, the nanowires are allowed to stand for 17-22 hours, then dried at -28 to -22°C for 10-14 hours and at -47 to -42°C for 10-14 hours. After drying, the nanowires are allowed to naturally return to room temperature and then placed in a muffle furnace. The temperature is increased to 800-815°C at a rate of 2.5-3.5°C / min and held for 2.0-2.5 hours. The nanowires are then cooled to room temperature in the furnace to obtain modified boron nitride nanowires. The mass ratio of the plasma-treated boron nitride nanowires to the composite adhesive is 9.5-10.6:

100.

5. The method for preparing a high-strength heat-insulating 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 zirconium oxide fiber 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 heat-insulating tile composite material according to claim 1, characterized in that, The method for preparing the acid-treated boron nitride particles is as follows: the boron nitride particles are placed in a mixed acid solution and ball-milled for 110-130 min, 200-220 rpm, a ball-to-material ratio of 2-4:1, using zirconia balls, and at a ball-milling temperature of 60-65℃. After ball milling, the solids are filtered out, washed, and dried to obtain the acid-treated boron nitride particles. The boron nitride particles have a particle size of 60-80 nm; The mixed acid solution is a mixture of concentrated nitric acid and concentrated sulfuric acid, with a volume ratio of 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 heat-insulating tile composite material according to claim 1, characterized in that, The calcination process in the preparation method of the modified zirconia fiber involves raising the temperature to 600-620℃ at a rate of 4.0-6.0℃ / min and holding the temperature for 1.0-1.4h. The zirconium oxide fiber has a length of 8.0-9.0 μm and a diameter of 15-25 nm; The mass ratio of aluminum nitrate, anhydrous ethanol, N-octanoyl-N-methylglucosamine, and polyvinylpyrrolidone is 8.0-8.5:100:0.6-0.8:0.8-1.

2. The mass ratio of the zirconium oxide fiber to the aluminum nitrate solution is 8-12:106-115.

8. The method for preparing a high-strength heat-insulating tile composite material according to claim 1, characterized in that, In the molding step, the mass ratio of the modified boron nitride nanowires, boron nitride particles / zirconia fiber composite, ethanol solution, ammonium polyacrylate, KH792, and isopropyltris(dioctylpyrophosphoryloxy)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 heat-insulating tile composite material according to claim 1, characterized in that, The calcination steps of the shaped blank are as follows: the shaped blank is placed in a calcination furnace, the temperature is increased to 750-800℃ at a rate of 2.5-3.5℃ / min, and held for 20-30min. Then the temperature is increased to 1300-1330℃ at a rate of 1.5-2.5℃ / min, and held for 2.0-2.5h. The blank is then cooled to room temperature with the furnace to obtain the heat insulation tile composite material.

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