A high-strength high-temperature heat-insulating material and its preparation method

Abstract

The present invention relates to a high-strength and high-temperature heat-insulating material and a preparation method thereof. The method: uniformly disperse zirconia fibers and zirconium carbide fibers with water, and make a wet fiber sheet by papermaking; mix solid phosphate, magnesia and chromium oxide and ball-mill them to obtain a filler, add a phosphate solution and mix and stir to obtain a high-temperature-resistant phosphate binder; coat the surface of the reflective screen with the high-temperature-resistant phosphate binder and cure it to obtain a modified reflective screen; alternately arrange a plurality of modified reflective screens and a plurality of wet fiber sheets, and obtain the high-strength and high-temperature heat-insulating material through molding and curing; in the alternate arrangement, one wet fiber sheet is arranged between every two modified reflective screens, and the surface of the wet fiber sheet is coated with the high-temperature-resistant phosphate binder. The present invention realizes the control of the high-temperature crystal form of phosphate, and at the same time performs an oxidation inhibition treatment on the reflective screen with the phosphate binder, improves the interfacial stability of the multi-layer material, and achieves the purpose of persistent application of the material under ultra-high temperature conditions.

Description

Technical Field

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

[0002] With the development of various aerospace vehicles towards high Mach numbers and long endurance, the power systems of the vehicles are facing increasingly harsh thermal environments; to prevent the influence of the high-temperature heat flow of the power system on the flight stability of the vehicle, it is necessary to carry out thermal protection on it. The high-temperature multi-layer thermal insulation material has excellent high-temperature anti-radiation performance and shows great advantages in the thermal protection structure of the power system, and has been widely used in various aerospace vehicles.

[0003] At present, the multi-layer thermal insulation material uses a high-temperature-resistant zirconia fiber thermal insulation material as the spacer layer and phosphate as the binder, and there is a huge problem that the high-temperature shaping ability is insufficient, especially the durability application stability of the material in the ultra-high-temperature environment is poor. The main reasons are as follows: First, common high-temperature binders such as aluminum phosphate, zirconium phosphate, and aluminum dihydrogen phosphate are prone to expand when heated at high temperatures, resulting in strength failure and other problems during long-term high-temperature application of the material, and it is difficult to maintain the structural stability of the material; second, the rapid oxidation of the reflective screen used in the high-temperature environment causes a sudden change in the interface structure, leading to the failure of the material structure.

[0004] Therefore, it is necessary to improve the problems of insufficient high-temperature resistance and strength of the phosphate high-temperature adhesive. In addition, it is also necessary to adopt the oxidation inhibition screen technology to prevent and realize the durable application of the high-temperature multi-layer material under ultra-high-temperature conditions and avoid structural failure.

[0005] In summary, it is very necessary to provide a high-strength and high-temperature-resistant thermal insulation material and a preparation method thereof. Summary of the Invention

[0006] In order to solve one or more technical problems existing in the prior art, the present invention provides a high-strength and high-temperature-resistant thermal insulation material and a preparation method thereof. The present invention prepares a high-strength and shapeable ultra-high-temperature thermal insulation material using a high-temperature-resistant phosphate as the binder. The binder used is a high-performance high-temperature-resistant binder prepared by multi-component compounding with phosphate as the main component, which can make the prepared thermal insulation material have the characteristics of ultra-high-temperature resistance and high strength, and can realize the durable application of the thermal insulation material under ultra-high-temperature conditions.

[0007] The present invention provides a preparation method of a high-strength and high-temperature-resistant thermal insulation material in the first aspect, and the method includes the following steps:

[0008] (1) Dispersing zirconia fibers and zirconium carbide fibers evenly with water to obtain a fiber slurry, and then forming a fiber wet sheet by papermaking the fiber slurry;

[0009] (2) Mix the solid phosphate, magnesia, and chromium oxide and perform ball milling to obtain a filler. Then, mix the phosphate solution with the filler and stir to obtain a high-temperature resistant phosphate binder.

[0010] (3) Coat the surface of the reflective screen with the high-temperature resistant phosphate binder and cure it to obtain a modified reflective screen.

[0011] (4) Alternately arrange multiple modified reflective screens and multiple fiber wet sheets, and then perform molding and curing to obtain a high-strength and high-temperature resistant heat insulation material. In the alternate arrangement, one fiber wet sheet is arranged between every two modified reflective screens, and the surface of the fiber wet sheet is coated with the high-temperature resistant phosphate binder.

[0012] Preferably, the diameter of the zirconia fiber is 3 - 10 μm, and the diameter of the zirconium carbide fiber is 2 - 5 μm; the sum of the mass percentages of the zirconia fiber and the zirconium carbide fiber contained in the fiber slurry is 0.2 - 3%; and / or the mass ratio of the zirconia fiber to the zirconium carbide fiber is (4 - 10):1.

[0013] Preferably, the thickness of the fiber wet sheet is 0.5 - 3 mm.

[0014] Preferably, the mass ratio of the solid phosphate, the magnesia, and the chromium oxide is (6 - 13):(2 - 7):(1 - 3); the solid phosphate is solid aluminum phosphate and / or solid zirconium phosphate; the particle size of the magnesia is 10 - 200 μm; and / or the ball milling time is 6 - 12 h.

[0015] Preferably, the stirring is carried out at room temperature for 3 - 6 h.

[0016] Preferably, the solid content of the phosphate solution is 20 - 60 wt%; the mass ratio of the phosphate solution to the filler is (2 - 9):1; and / or the phosphate solution is one or more of aluminum dihydrogen phosphate solution, aluminum phosphate solution, and zirconium phosphate solution.

[0017] Preferably, the thickness of the high-temperature resistant phosphate binder coated on the surface of the reflective screen is 30 - 90 μm; and / or the thickness of the high-temperature resistant phosphate binder coated on the surface of the fiber wet sheet is 30 - 90 μm.

[0018] Preferably, in step (3) and / or step (4), the curing is as follows: first cure at 80 - 100 °C for 4 - 8 h, and then cure at 120 - 180 °C for 10 - 15 h.

[0019] Preferably, in step (2): the filler further contains aluminum-magnesium spinel. Preferably, in the filler, the mass ratio of the solid phosphate, the magnesia, the chromium oxide, and the aluminum-magnesium spinel is (6-13):(2-7):(1-3):(1-5); and / or after stirring, zirconium carbide whiskers and aluminum nitride fibers are further added and dispersed evenly, and then magnesia powder is added and dispersed evenly to obtain the high-temperature resistant phosphate binder.

[0020] In a second aspect, the present invention provides a high-strength and high-temperature resistant thermal insulation material prepared by the preparation method described in the first aspect of the present invention.

[0021] Compared with the prior art, the present invention has at least the following beneficial effects:

[0022] The high-temperature resistant phosphate binder adopted in the present invention realizes the control of the high-temperature crystal form of phosphate by ball milling the interface modification of magnesia, phosphate, and chromium oxide, completes the improvement of the temperature resistance of the phosphate binder, and obtains a high-performance high-temperature resistant binder with a multi-component compound with phosphate as the main component; at the same time, the present invention pre-coats the reflective screen with the high-temperature resistant phosphate binder and cures it at high temperature, realizes the oxidation inhibition treatment of the reflective screen, improves the interface stability of the multi-layer material, and finally realizes the preparation of a high-strength and ultra-high temperature resistant multi-layer thermal insulation material, achieving the purpose of persistent application of the material and effectively avoiding the failure of the structure of the thermal insulation material under ultra-high temperature conditions. Detailed Embodiments

[0023] To make the purpose, technical solutions, and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0024] In a first aspect, the present invention provides a preparation method of a high-strength and high-temperature resistant thermal insulation material, and the method includes the following steps:

[0025] (1) Dispersing zirconia fiber and zirconium carbide fiber evenly with water to obtain a fiber slurry, and then forming a fiber wet sheet by sheet-forming the fiber slurry; in the present invention, specifically, a certain amount of zirconia fiber and zirconium carbide fiber are weighed in water, and after being dispersed evenly by a beater, a fiber slurry is obtained. The fiber slurry is formed into a fiber wet sheet by a sheet former. For example, the fiber slurry is placed in the material bucket of the sheet former, homogenized manually or automatically, and then the sheet former is started to form a fiber wet sheet with a certain thickness through the sheet former;

[0026] (2) Mix solid phosphate, magnesia, and chromium oxide (chromium sesquioxide), and perform ball milling to obtain a filler (also denoted as a high-temperature filler). Then, mix the phosphate solution with the filler and stir to obtain a high-temperature resistant phosphate binder. The present invention does not specifically limit the rotation speed of stirring. For example, it can be 200 - 800 r / min;

[0027] (3) Coat the surface of the reflective screen with the high-temperature resistant phosphate binder and cure it to obtain a modified reflective screen. In the present invention, at least on the surface of the reflective screen in contact with the fiber wet sheet, the high-temperature resistant phosphate binder obtained in step (2) is coated. The present invention has no special requirements for the reflective screen. The reflective screen can be, for example, one or more of graphite paper, graphite cloth, and carbon fiber cloth. The thickness of the reflective screen is, for example, 0.025 - 0.1 mm;

[0028] (4) Alternately arrange a plurality of the modified reflective screens and a plurality of the fiber wet sheets, and then perform molding and curing to obtain a high-strength high-temperature resistant thermal insulation material. In the alternate arrangement, one fiber wet sheet is arranged between every two modified reflective screens, and the surface of the fiber wet sheet is coated with the high-temperature resistant phosphate binder. In the present invention, on the surface of the fiber wet sheet in contact with the modified reflective screen, the high-temperature resistant phosphate binder obtained in step (2) is coated. In the present invention, for example, a pressing tooling can be used for the molding. The present invention has no special requirements for the parameters of the molding. The existing conventional molding parameters can be used for the molding. For example, the pressure of the molding is 0.5 - 3 MPa, and the molding time is 10 - 90 min. The present invention has no special requirements for the number of the modified reflective screens and the fiber wet sheets arranged. It can be optimized according to the actual application situation (such as the total thickness requirement of the high-strength high-temperature resistant thermal insulation material in actual application, etc.). Preferably, the thickness of the high-strength high-temperature resistant thermal insulation material is 5 - 60 mm. The high-strength high-temperature resistant thermal insulation material prepared in the present invention can achieve persistent application under ultra-high temperature conditions, and thus is also denoted as a high-strength ultra-high temperature resistant multi-layer thermal insulation material. In the present invention, the ultra-high temperature condition refers to a high temperature condition above 1500 °C.

[0029] The present invention first prepares a fiber wet sheet by compounding zirconium carbide fibers and zirconium oxide fibers with excellent high-temperature stability, and then prepares a high-strength and high-temperature-resistant phosphate binder. First, solid phosphate, magnesia, and chromium oxide are mixed and placed in a ball mill jar for ball milling to complete modification; magnesia can be used to improve the high-temperature shape-holding ability of the phosphate binder; at the same time, the mixed matrix of phosphate and chromium oxide realizes micro-scale blending modification of magnesia through ball milling, realizes the control of the high-temperature crystal form of phosphate, and avoids the high-temperature failure of the phosphate binder. Then, the phosphate solution and high-temperature fillers are stirred to form the high-temperature-resistant phosphate binder. Then, the surface of the reflective screen is coated with the high-temperature-resistant phosphate binder, cured at high temperature, and subjected to oxidation inhibition modification. Finally, multiple modified reflective screens and fiber wet sheets are alternately arranged, and the high-temperature-resistant phosphate binder is coated on the interface of the fiber wet sheet, and after molding and curing, the high-strength and ultra-high-temperature-resistant multi-layer thermal insulation material is obtained.

[0030] The high-temperature-resistant phosphate binder adopted in the present invention realizes the control of the high-temperature crystal form of phosphate through the interfacial modification of magnesia, phosphate, and chromium oxide by ball milling, completes the improvement of the temperature resistance of the phosphate binder, and obtains a high-performance high-temperature-resistant binder with a multi-component compounding mainly composed of phosphate. In addition, in the present invention, solid phosphate is added to the filler, which can increase the content of phosphate with high-temperature-resistant crystal forms, is beneficial to improving the dispersibility between the phosphate solution and other filler components, and promotes pre-crosslinking, thereby being beneficial to improving the performance of the phosphate binder and helping to optimize the composition of the phosphate binder; at the same time, the present invention pre-coats the reflective screen with the high-temperature-resistant phosphate binder and cures it at high temperature, realizes the oxidation inhibition treatment of the reflective screen, improves the interfacial stability of the multi-layer material, and finally realizes the preparation of the high-strength and ultra-high-temperature-resistant multi-layer thermal insulation material, achieving the purpose of the durable application of the material and effectively avoiding the failure of the structure of the thermal insulation material under ultra-high-temperature conditions.

[0031] According to some preferred embodiments, the diameter (average diameter) of the zirconia fiber is 3 - 10 μm, and the diameter (average diameter) of the zirconium carbide fiber is 2 - 5 μm; in the present invention, preferably, the diameter of the zirconia fiber is 3 - 10 μm and the diameter of the zirconium carbide fiber is 2 - 5 μm. More preferably, the diameter of the zirconia fiber used is greater than that of the zirconium carbide fiber. This compounding of fiber size differences can improve the strength of the fiber wet sheet, facilitating subsequent operations. Since the zirconium carbide fiber has good heat resistance but high thermal conductivity, it is preferred that the diameter of the zirconium carbide fiber is finer. The sum of the mass percentages (mass fractions) of the zirconia fiber and the zirconium carbide fiber in the fiber slurry is 0.2 - 3% (such as 0.2%, 0.5%, 0.8%, 1%, 1.2%, 1.5%, 1.8%, 2%, 2.2%, 2.5%, 2.8% or 3%). Within this mass fraction range, effective dispersion and overlap of the fibers can be ensured, effectively avoiding the situation of uneven dispersion or low overlap compounding degree; and / or the mass ratio of the zirconia fiber to the zirconium carbide fiber is (4 - 10):1 (such as 4:1, 5:1, 6:1, 7:1, 8:1, 9:1 or 10:1).

[0032] According to some preferred embodiments, the thickness of the fiber wet sheet is 0.5 - 3 mm; in the present invention, to ensure the uniformity of the thermal insulation material and the stability of the coating of the high-temperature resistant phosphate binder, and at the same time ensure the excellent high-temperature infrared radiation suppression performance of the multi-layer material, preferably, the thickness of the fiber wet sheet is 0.5 - 3 mm, and the thickness of the reflective screen is 0.025 - 0.1 mm.

[0033] According to some preferred embodiments, the mass ratio of the solid phosphate, the magnesia, and the chromium oxide is (6 - 13):(2 - 7):(1 - 3); the present invention has obtained this preferred ratio through a large number of creative experiments. The present invention discovers that this ratio can achieve effective control of the crystal form and realize the high-temperature resistant modification design of the phosphate binder system, thereby ensuring the acquisition of a phosphate binder with ultra-high temperature resistance and high strength. In the present invention, if the proportion of each component is not within this preferred range, it will lead to the failure of crystal form control, and an inappropriate mass ratio may cause non-uniform composition and unstable crystal structure of the material, thereby reducing the overall performance of the phosphate binder under high-temperature conditions.

[0034] According to some preferred embodiments, the solid phosphate is aluminum-based phosphate and / or zirconium-based phosphate. Preferably, the solid phosphate is aluminum phosphate and / or zirconium phosphate; the particle size (average particle size) of the magnesia is 10-200 μm (such as 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190 or 200 μm). In the present invention, preferably, the particle size of the magnesia is 10-200 μm. If the particle size of the magnesia is too small, it is easy to agglomerate, resulting in poor high-temperature stability of the prepared phosphate binder. If the particle size of the magnesia is too large, it is difficult to form a modified eutectic system with phosphate and chromium oxide during the ball milling process, which is also not conducive to improving the high-temperature stability of the phosphate binder; and / or the ball milling time is 6-12 h (such as 6, 7, 8, 9, 10, 11 or 12 h).

[0035] According to some preferred embodiments, the stirring is carried out at room temperature for 3-6 h (such as 3, 4, 5 or 6 h); in the present invention, the room temperature can be, for example, room temperature of 20-30 °C.

[0036] According to some preferred embodiments, the solid content of the phosphate solution is 20-60 wt% (such as 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt%, 50 wt%, 55 wt% or 60 wt%), that is, the mass fraction of phosphate contained in the phosphate solution is 20-60 wt%; and / or the mass ratio of the phosphate solution to the filler is (2-9):1 (such as 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1 or 9:1).

[0037] In the present invention, preferably, the mass ratio of the phosphate solution to the filler is (2-9):1, which is beneficial to ensuring the acquisition of a phosphate binder with ultra-high temperature resistance and high strength. Within this preferred ratio range, different viscosity high-temperature resistant adhesives can be prepared according to the different viscosity requirements of the phosphate binder system, so as to better adapt to the actual application situation; in the present invention, preferably, the solid content of the phosphate solution is controlled at 20 wt% - 60 wt%. If the solid content in the phosphate solution is too large, there will be few high-temperature resistant components in the phosphate binder of the present invention, and it is difficult to effectively improve the temperature resistance of the binder. If there are too many high-temperature resistant components, the high-temperature strength of the phosphate binder will be limitedly improved.

[0038] According to some preferred embodiments, the phosphate solution is one or more of aluminum dihydrogen phosphate solution, aluminum phosphate solution, and zirconium phosphate solution; in the present invention, the phosphate is aluminum-based phosphate and / or zirconium-based phosphate; in the present invention, the phosphate solution refers to an aqueous phosphate solution.

[0039] According to some preferred embodiments, the thickness of the high-temperature resistant phosphate binder coated on the surface of the reflective screen is 30-90 μm (such as 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85 or 90 μm). In the present invention, preferably, the thickness of the high-temperature resistant phosphate binder coated on the surface of the reflective screen is 30-90 μm. The present invention finds that if the adhesive layer on the reflective screen is too thin, the oxidation inhibition effect is poor, and if the adhesive layer is too thick, the reflective screen is prone to embrittlement; and / or the surface of the fiber wet sheet is coated with the high-temperature resistant phosphate binder with a thickness of 30-90 μm (such as 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85 or 90 μm).

[0040] According to some preferred embodiments, in step (3) and / or step (4), the curing is as follows: first cure at 80-100 °C (such as 80 °C, 90 °C or 100 °C) for 4-8 h (such as 4, 5, 6, 7 or 8 h), and then cure at 120-180 °C (such as 120 °C, 130 °C, 140 °C, 150 °C, 160 °C, 170 °C or 180 °C) for 10-15 h (such as 10, 11, 12, 13, 14 or 15 h). In the present invention, gradient temperature curing is preferably carried out, so that the phosphate binder can be effectively prevented from bubbling and other situations, which is beneficial to ensuring the overall performance of the phosphate binder and the high-strength high-temperature resistant thermal insulation material.

[0041] According to some preferred embodiments, in step (2): the filler further contains aluminum-magnesium spinel. Preferably, in the filler, the mass ratio of the solid phosphate, the magnesite, the chromium oxide and the aluminum-magnesium spinel is (6-13):(2-7):(1-3):(1-5). The present invention obtains this preferred ratio through a large number of creative experiments. The present invention finds that this ratio can effectively control the crystal form and effectively realize the high-temperature modification design of the phosphate binder system; and / or after stirring, zirconium carbide whiskers and aluminum nitride fibers are further added and dispersed evenly, and then magnesium oxide powder is added and dispersed evenly to obtain the high-temperature resistant phosphate binder.

[0042] Preferably, the high-temperature resistant phosphate binder used in the present invention simultaneously uses magnesite and spinel as ultra-high temperature components. The mixed matrix of phosphate and chromium oxide realizes the micro-scale blending modification of magnesite and spinel through ball milling, which can better control the high-temperature crystal form of phosphate. Moreover, the ball milling process can enable magnesite and spinel to form a modified eutectic system with phosphate and chromium oxide, thereby avoiding the high-temperature failure of the high-temperature adhesive (phosphate binder); avoiding the failure of phosphate at high temperatures or even ultra-high temperatures (above 1500 °C); at the same time, introducing high-temperature resistant reinforcing fibers (aluminum nitride fibers) and nanowhiskers (zirconium carbide whiskers) to toughen the high-temperature adhesive system (pre-crosslinked system). Densifying the reinforcement with a liquid phosphate binder (phosphate solution) can enable the reinforcement to be more closely combined with the main component, significantly improving the high-temperature strength of the phosphate binder, which is beneficial to further improving the high-temperature resistance and high-temperature strength of the prepared high-strength high-temperature resistant thermal insulation material.

[0043] After mixing the phosphate solution (liquid phosphate) with the filler and stirring to form a pre-crosslinked system, preferably, zirconium carbide whiskers and aluminum nitride fibers are added to the pre-crosslinked system, stirred and dispersed evenly, and then magnesium oxide powder is added and stirred and dispersed evenly to obtain the high-temperature resistant phosphate binder. By first forming a pre-crosslinked system to construct a basic network structure in the binder and then adding zirconium carbide whiskers, aluminum nitride fibers and magnesium oxide powder, it is easier to achieve the uniform dispersion of these compound components, which helps to ensure that each component can be fully distributed in the entire phosphate binder, better ensures the interaction between components, and maximally utilizes the toughening performance and high-temperature stability of zirconium carbide whiskers, aluminum nitride fibers and magnesium oxide powder, thereby significantly enhancing the overall performance of the phosphate binder; in addition, magnesium oxide powder is added to the pre-crosslinked system in the present invention. The addition of the magnesium oxide powder is beneficial to improving the high-temperature stability of the phosphate binder, can better control the thermal expansion performance of the phosphate binder, and can more effectively avoid the problems of fracture or damage caused by thermal expansion mismatch; the preferred technical solution of the present invention also obtains a high-performance high-temperature resistant binder with multiple components compounded with phosphate as the main component, which has the characteristics of high-temperature resistance without expansion and high strength, and is beneficial to further improving the high-temperature resistance and high-temperature strength of the prepared high-strength high-temperature resistant thermal insulation material.

[0044] According to some specific embodiments, step (2) is as follows: Mix solid phosphate, magnesia, chromium oxide (chromium sesquioxide), and spinel and perform ball milling to obtain a filler (also denoted as a high-temperature filler), then mix the phosphate solution with the filler and stir to obtain a pre-crosslinked system, then add zirconium carbide whiskers and aluminum nitride fibers to the pre-crosslinked system and disperse evenly, and then add magnesia powder and disperse evenly to obtain the high-temperature resistant phosphate binder; in the present invention, for example, it can be dispersed evenly by stirring, and the present invention does not specifically limit the rotation speed of the stirring, for example, it can be 200 - 800 r / min.

[0045] The present invention does not specifically limit the sources of each raw material, and products that can be directly purchased on the market or products synthesized by existing methods can be used.

[0046] According to some preferred embodiments, the particle size (average particle size) of the spinel is 20 - 500 μm (for example, 20, 50, 80, 100, 150, 200, 250, 300, 350, 400, 450, or 500 μm); in the present invention, preferably, the particle size of the spinel is 20 - 500 μm. If the particle size of the spinel is too small, it is easy to agglomerate, which will result in poor high-temperature stability of the prepared phosphate binder. If the particle size of the spinel is too large, it is difficult to form a modified eutectic system with phosphate and chromium oxide during the ball milling process, which is also not conducive to improving the high-temperature stability of the phosphate binder.

[0047] According to some preferred embodiments, the aspect ratio of the zirconium carbide whiskers is (5 - 100):1; in the present invention, the particle size of the zirconium carbide whiskers is, for example, 10 - 100 nm; and / or the length (average length) of the aluminum nitride fibers is 3 - 8 μm; in the present invention, the diameter of the aluminum nitride fibers can be, for example, 100 - 1000 nm; in the present invention, preferably, the aspect ratio of the zirconium carbide whiskers is (5 - 100):1, and the length of the aluminum nitride fibers is 3 - 8 μm. If the aspect ratio of the zirconium carbide whiskers is too small and the length of the aluminum nitride fibers is too small, it cannot play an effective toughening role. If the aspect ratio of the zirconium carbide whiskers is too large and the length of the aluminum nitride fibers is too large, it is easy to adhere and agglomerate, which is also not conducive to improving the overall bonding performance of the phosphate binder.

[0048] The present invention has no special requirements for the particle sizes of the chromium oxide and magnesia powders, and micro-powders or nano-powders can be selected. In some specific embodiments, the particle size of the magnesia powder is, for example, 0.1 - 1 μm, and the particle size of the chromium oxide (chromium oxide powder) is, for example, 15 - 75 μm.

[0049] According to some preferred embodiments, the mass ratio of the silicon carbide whiskers to the pre-crosslinked system is 1:(20 - 30); the mass ratio of the aluminum nitride fibers to the pre-crosslinked system is 1:(30 - 60); and / or the mass ratio of the magnesium oxide powder to the pre-crosslinked system is 1:(15 - 30); in the present invention, in order to ensure the effective dispersion and toughening of the components and the magnesium oxide powder component, and more effectively ensure the high temperature resistance and high strength characteristics of the phosphate binder, the present invention has obtained the most preferred amounts of silicon carbide whiskers, aluminum nitride fibers and magnesium oxide powder through a large number of creative experiments. In the present invention, preferably, the mass ratio of the silicon carbide whiskers to the pre-crosslinked system is 1:(20 - 30), the mass ratio of the aluminum nitride fibers to the pre-crosslinked system is 1:(30 - 60), and the mass ratio of the magnesium oxide powder to the pre-crosslinked system is 1:(15 - 30).

[0050] In a second aspect, the present invention provides a high-strength and high-temperature resistant thermal insulation material prepared by the preparation method described in the first aspect of the present invention.

[0051] The present invention will be further described by way of examples below, but the protection scope of the present invention is not limited to these embodiments.

[0052] It should be specifically noted that in the present invention, "parts" all refer to "parts by weight". In specific examples and comparative examples, the unit of parts by weight can be uniformly adopted as weight units such as "g" or "kg".

[0053] Example 1

[0054] ① Weigh 80 parts of zirconia fibers (diameter 3 μm) and 20 parts of zirconium carbide fibers (diameter 2 μm), disperse them evenly in water, and obtain a fiber slurry with a mass fraction of 0.2% (the sum of the mass fractions of zirconia fibers and zirconium carbide fibers contained in the fiber slurry is 0.2%). Use a sheet former to make a fiber wet sheet with a thickness of 0.5 mm from the fiber slurry.

[0055] ② Mix 6 parts of solid aluminum phosphate, 2 parts of magnesite (particle size 200 μm), and 1 part of chromium oxide, place them in a ball mill jar and ball mill for 8 h to obtain a filler. Mix 81 parts of an aluminum dihydrogen phosphate solution with a solid content of 40 wt% with the obtained filler and stir at 25 °C for 5 h to obtain a high-temperature resistant phosphate binder.

[0056] ③ Pre-coat the surface of the reflective screen (graphite paper with a thickness of 0.025 mm) that needs to be in contact with the fiber wet sheet with the high-temperature resistant phosphate binder obtained in step ②, control the coating thickness of the high-temperature resistant phosphate binder to be 30 μm, cure at 90 °C for 6 h first, and then raise the temperature to 150 °C and cure for 12 h to obtain a modified reflective screen.

[0057] ④ The 11 modified reflective screens prepared by the method in step ③ and the 10 fiber wet sheets obtained in step ① are alternately arranged. In the alternate arrangement, one of the fiber wet sheets is arranged between every two modified reflective screens. The surface of the fiber wet sheet in contact with the modified reflective screen is coated with the high-temperature-resistant phosphate binder obtained in step ②. The coating thickness of the high-temperature-resistant phosphate binder is controlled to be 30 μm. After being molded under a pressure of 1 MPa for 60 min, it is first cured at 90 °C for 6 h, and then the temperature is raised to 150 °C and cured for 12 h to obtain a high-strength high-temperature-resistant heat-insulating material.

[0058] Example 2

[0059] ① Weigh 80 parts of zirconia fibers (with a diameter of 3 μm) and 20 parts of zirconium carbide fibers (with a diameter of 2 μm), disperse them evenly in water to obtain a fiber slurry with a mass fraction of 3% (the sum of the mass fractions of zirconia fibers and zirconium carbide fibers contained in the fiber slurry is 3%). The fiber slurry is made into a fiber wet sheet with a thickness of 1 mm by a fourdrinier machine.

[0060] ② Mix 13 parts of solid aluminum phosphate, 7 parts of magnesia (with a particle size of 200 μm), and 3 parts of chromium oxide, place them in a ball mill tank and ball mill for 8 h to obtain a filler. Mix 100 parts of an aluminum dihydrogen phosphate solution with a solid content of 40 wt% and the obtained filler, and stir at 25 °C for 5 h to obtain a high-temperature-resistant phosphate binder.

[0061] ③ The surface of the reflective screen (graphite paper with a thickness of 0.025 mm) that needs to be in contact with the fiber wet sheet is pre-coated with the high-temperature-resistant phosphate binder obtained in step ②. The coating thickness of the high-temperature-resistant phosphate binder is controlled to be 50 μm. It is first cured at 90 °C for 6 h, and then the temperature is raised to 150 °C and cured for 12 h to obtain a modified reflective screen.

[0062] ④ The 6 modified reflective screens prepared by the method in step ③ and the 5 fiber wet sheets obtained in step ① are alternately arranged. In the alternate arrangement, one of the fiber wet sheets is arranged between every two modified reflective screens. The surface of the fiber wet sheet in contact with the modified reflective screen is coated with the high-temperature-resistant phosphate binder obtained in step ②. The coating thickness of the high-temperature-resistant phosphate binder is controlled to be 50 μm. After being molded under a pressure of 1 MPa for 60 min, it is first cured at 90 °C for 6 h, and then the temperature is raised to 150 °C and cured for 12 h to obtain a high-strength high-temperature-resistant heat-insulating material.

[0063] Example 3

[0064] ① Weigh 85 parts of zirconia fibers (with a diameter of 3 μm) and 15 parts of zirconium carbide fibers (with a diameter of 2 μm), disperse them evenly in water, and obtain a fiber slurry with a mass fraction of 1% (the sum of the mass fractions of zirconia fibers and zirconium carbide fibers contained in the fiber slurry is 1%). Then, use a sheet former to make a fiber wet sheet with a thickness of 3 mm from the fiber slurry.

[0065] ② Mix 7 parts of solid aluminum phosphate, 4 parts of magnesia (with a particle size of 200 μm), and 1 part of chromium oxide, place them in a ball mill jar and ball mill for 8 h to obtain a filler. Then, mix 24 parts of an aluminum dihydrogen phosphate solution with a solid content of 40 wt% with the obtained filler and stir at 25 °C for 5 h to obtain a high-temperature resistant phosphate binder.

[0066] ③ Pre-coat the surface of the reflective screen (graphite paper with a thickness of 0.025 mm) that needs to be in contact with the fiber wet sheet with the high-temperature resistant phosphate binder obtained in step ②, control the coating thickness of the high-temperature resistant phosphate binder to be 90 μm, first cure at 90 °C for 6 h, and then raise the temperature to 150 °C and cure for 12 h to obtain a modified reflective screen.

[0067] ④ Alternately arrange 4 modified reflective screens prepared by the method in step ③ and 3 fiber wet sheets obtained in step ①. In the alternate arrangement, one of the fiber wet sheets is arranged between every two modified reflective screens. Coat the surface of the fiber wet sheet in contact with the modified reflective screen with the high-temperature resistant phosphate binder obtained in step ②, control the coating thickness of the high-temperature resistant phosphate binder to be 90 μm. After molding under a pressure of 1 MPa for 60 min, first cure at 90 °C for 6 h, and then raise the temperature to 150 °C and cure for 12 h to obtain a high-strength high-temperature resistant thermal insulation material.

[0068] Example 4

[0069] ① Weigh 85 parts of zirconia fibers (with a diameter of 3 μm) and 15 parts of zirconium carbide fibers (with a diameter of 2 μm), disperse them evenly in water, and obtain a fiber slurry with a mass fraction of 1% (the sum of the mass fractions of zirconia fibers and zirconium carbide fibers contained in the fiber slurry is 1%). Then, use a sheet former to make a fiber wet sheet with a thickness of 3 mm from the fiber slurry.

[0070] ② Mix 7 parts of solid zirconium phosphate, 4 parts of magnesia (with a particle size of 200 μm), and 1 part of chromium oxide, place them in a ball mill jar and ball mill for 8 h to obtain a filler. Then, mix 24 parts of an aluminum dihydrogen phosphate solution with a solid content of 40 wt% with the obtained filler and stir at 25 °C for 5 h to obtain a high-temperature resistant phosphate binder.

[0071] ③Precoat the surface of the reflective screen (graphite paper with a thickness of 0.025 mm) that needs to be in contact with the fiber wet sheet with the high-temperature resistant phosphate binder obtained in step ②, control the coating thickness of the high-temperature resistant phosphate binder to be 90 μm, cure it at 90 °C for 6 h first, and then raise the temperature to 150 °C and cure it for 12 h to obtain a modified reflective screen.

[0072] ④Alternately arrange 4 modified reflective screens prepared by the method in step ③ and 3 fiber wet sheets obtained in step ①. In the alternate arrangement, one of the fiber wet sheets is arranged between every two modified reflective screens. The surface of the fiber wet sheet in contact with the modified reflective screen is coated with the high-temperature resistant phosphate binder obtained in step ②. Control the coating thickness of the high-temperature resistant phosphate binder to be 90 μm. After molding under a pressure of 1 MPa for 60 min, then cure it at 90 °C for 6 h first, and then raise the temperature to 150 °C and cure it for 12 h to obtain a high-strength high-temperature resistant thermal insulation material.

[0073] Example 5

[0074] ①Weigh 90 parts of zirconia fiber (with a diameter of 8 μm) and 10 parts of zirconium carbide fiber (with a diameter of 5 μm), disperse them evenly in water to obtain a fiber slurry with a mass fraction of 1% (the sum of the mass fractions of zirconia fiber and zirconium carbide fiber contained in the fiber slurry is 1%). Pass the fiber slurry through a fourdrinier machine to make a fiber wet sheet with a thickness of 1 mm.

[0075] ②Mix 7 parts of solid zirconium phosphate, 4 parts of magnesia (with a particle size of 200 μm), and 1 part of chromium oxide, place them in a ball mill jar and ball mill for 8 h to obtain a filler. Mix 24 parts of an aluminum dihydrogen phosphate solution with a solid content of 40 wt% and the obtained filler, and stir at 25 °C for 5 h to obtain a high-temperature resistant phosphate binder.

[0076] ③Precoat the surface of the reflective screen (graphite paper with a thickness of 0.025 mm) that needs to be in contact with the fiber wet sheet with the high-temperature resistant phosphate binder obtained in step ②, control the coating thickness of the high-temperature resistant phosphate binder to be 90 μm, cure it at 90 °C for 6 h first, and then raise the temperature to 150 °C and cure it for 12 h to obtain a modified reflective screen.

[0077] ④Alternately arrange 6 modified reflective screens prepared by the method in step ③ and 5 fiber wet sheets obtained in step ①. In the alternate arrangement, one of the fiber wet sheets is arranged between every two modified reflective screens. The surface of the fiber wet sheet in contact with the modified reflective screen is coated with the high-temperature resistant phosphate binder obtained in step ②. Control the coating thickness of the high-temperature resistant phosphate binder to be 90 μm. After molding under a pressure of 1 MPa for 60 min, then cure it at 90 °C for 6 h first, and then raise the temperature to 150 °C and cure it for 12 h to obtain a high-strength high-temperature resistant thermal insulation material.

[0078] Example 6

[0079] ① Weigh 80 parts of zirconia fibers (with a diameter of 3 μm) and 20 parts of zirconium carbide fibers (with a diameter of 2 μm), disperse them evenly in water, and obtain a fiber slurry with a mass fraction of 0.2% (the sum of the mass fractions of zirconia fibers and zirconium carbide fibers contained in the fiber slurry is 0.2%). Then, use a sheet former to produce a fiber wet sheet with a thickness of 0.5 mm from the fiber slurry.

[0080] ② Mix 6 parts of solid aluminum phosphate, 2 parts of magnesia (with a particle size of 200 μm), 1 part of chromium oxide, and 1 part of aluminum-magnesium spinel (with a particle size of 20 μm), place them in a ball mill and ball mill for 8 h to obtain a filler. Mix 90 parts of an aluminum dihydrogen phosphate solution with a solid content of 40 wt% with the obtained filler, stir at 25 °C for 5 h to obtain a pre-crosslinked system. Then, add 5 parts of zirconium carbide whiskers (aspect ratio of 100) and 3.5 parts of aluminum nitride fibers with a length of 8 μm to the obtained pre-crosslinked system, stir and disperse evenly, and then add 5 parts of magnesium oxide powder, stir and disperse evenly to obtain a high-temperature resistant phosphate binder.

[0081] ③ Pre-coat the surface of the reflective screen (graphite paper with a thickness of 0.025 mm) that needs to be in contact with the fiber wet sheet with the high-temperature resistant phosphate binder obtained in step ②, control the coating thickness of the high-temperature resistant phosphate binder to be 30 μm, cure at 90 °C for 6 h first, and then raise the temperature to 150 °C and cure for 12 h to obtain a modified reflective screen.

[0082] ④ Alternately arrange 11 modified reflective screens prepared by the method in step ③ and 10 fiber wet sheets obtained in step ①. In the alternate arrangement, one of the fiber wet sheets is arranged between every two modified reflective screens. Coat the surface of the fiber wet sheet in contact with the modified reflective screen with the high-temperature resistant phosphate binder obtained in step ②, control the coating thickness of the high-temperature resistant phosphate binder to be 30 μm. After molding under a pressure of 1 MPa for 60 min, then cure at 90 °C for 6 h first, and then raise the temperature to 150 °C and cure for 12 h to obtain a high-strength high-temperature resistant thermal insulation material.

[0083] Comparative Example 1

[0084] ① Weigh 90 parts of zirconia fibers (with a diameter of 8 μm) and 10 parts of zirconium carbide fibers (with a diameter of 5 μm), disperse them evenly in water, and obtain a fiber slurry with a mass fraction of 1% (the sum of the mass fractions of zirconia fibers and zirconium carbide fibers contained in the fiber slurry is 1%). Then, use a sheet former to produce a fiber wet sheet with a thickness of 1 mm from the fiber slurry.

[0085] ② Alternately arrange 6 reflective screens (graphite paper with a thickness of 0.025 mm) and 5 fiber wet sheets obtained in step ①. In the alternating arrangement, one fiber wet sheet is arranged between every two reflective screens. The surface of the fiber wet sheet in contact with the reflective screen is coated with a dihydrogen aluminum phosphate solution with a solid content of 40 wt%. The coating thickness of the dihydrogen aluminum phosphate solution is controlled to be 90 μm. After molding at a pressure of 1 MPa for 60 minutes, the fiber wet sheet is cured at a high temperature of 150°C for 24 hours to obtain a thermal insulation material.

[0086] Comparative Example 2

[0087] ① Weigh 90 parts of zirconium oxide fiber (with a diameter of 8 μm) and 10 parts of zirconium carbide fiber (with a diameter of 5 μm) and disperse them evenly in water to obtain a fiber slurry with a mass fraction of 1% (the sum of the mass fractions of zirconium oxide fiber and zirconium carbide fiber contained in the fiber slurry is 1%). Use a sheet making machine to make a fiber wet sheet with a thickness of 1 mm.

[0088] ② Mix 7 parts of solid zirconium phosphate, 4 parts of magnesia (particle size of 200 μm), and 1 part of chromium oxide, place them in a ball mill and ball mill for 8 hours to obtain a filler, mix 24 parts of aluminum dihydrogen phosphate solution with a solid content of 40 wt% with the obtained filler, stir at 25 ° C for 5 hours, and obtain a high temperature resistant phosphate adhesive.

[0089] ③ Alternately arrange 6 reflective screens (graphite paper with a thickness of 0.025 mm) and 5 fiber wet sheets obtained in step ①. In the alternating arrangement, one fiber wet sheet is arranged between every two reflective screens. The surface of the fiber wet sheet in contact with the reflective screen is coated with the high-temperature resistant phosphate adhesive obtained in step ②. The coating thickness of the high-temperature resistant phosphate adhesive is controlled to be 90 μm. After molding at a pressure of 1 MPa for 60 minutes, it is first cured at 90°C for 6 hours and then heated to 150°C for curing for 12 hours to obtain a thermal insulation material.

[0090] Comparative Example 3

[0091] ① Weigh 90 parts of zirconium oxide fiber (with a diameter of 8 μm) and 10 parts of zirconium carbide fiber (with a diameter of 5 μm) and disperse them evenly in water to obtain a fiber slurry with a mass fraction of 1% (the sum of the mass fractions of zirconium oxide fiber and zirconium carbide fiber contained in the fiber slurry is 1%). Use a sheet making machine to make a fiber wet sheet with a thickness of 1 mm.

[0092] ② Pre-coat the surface of the reflective screen (graphite paper with a thickness of 0.025 mm) that needs to contact the fiber wet sheet with a dihydrogen aluminum phosphate solution with a solid content of 40 wt%, control the coating thickness of the dihydrogen aluminum phosphate solution to 90 μm, and then cure it at 150°C for 24 hours to obtain a modified reflective screen.

[0093] ③Arrange the 6 modified reflective screens prepared by the method in step ② and the 5 fiber wet sheets obtained in step ① alternately. During the alternate arrangement, one of the fiber wet sheets is arranged between every two modified reflective screens. An aluminum dihydrogen phosphate solution with a solid content of 40 wt% is coated on the surface of the fiber wet sheet in contact with the modified reflective screen. Control the coating thickness of the aluminum dihydrogen phosphate solution to be 90 μm. After molding under a pressure of 1 MPa for 60 min, then cure at a high temperature of 150 °C for 24 h to obtain the heat-insulating material.

[0094] Comparative Example 4

[0095] ①Weigh 90 parts of zirconia fiber (with a diameter of 8 μm) and 10 parts of zirconium carbide fiber (with a diameter of 5 μm), disperse them evenly in water to obtain a fiber slurry with a mass fraction of 5% (the sum of the mass fractions of zirconia fiber and zirconium carbide fiber contained in the fiber slurry is 5%). Pass the fiber slurry through a fourdrinier machine to make a fiber wet sheet with a thickness of 1 mm.

[0096] ②Mix 7 parts of solid zirconium phosphate, 4 parts of magnesia (with a particle size of 200 μm), and 1 part of chromium oxide, place them in a ball mill jar and ball mill for 8 h to obtain a filler. Mix 24 parts of an aluminum dihydrogen phosphate solution with a solid content of 40 wt% with the obtained filler and stir at 25 °C for 5 h to obtain a high-temperature resistant phosphate binder.

[0097] ③Pre-coat the surface of the reflective screen (graphite paper with a thickness of 0.025 mm) that needs to be in contact with the fiber wet sheet with the high-temperature resistant phosphate binder obtained in step ②. Control the coating thickness of the high-temperature resistant phosphate binder to be 90 μm. First cure at 90 °C for 6 h, and then raise the temperature to 150 °C and cure for 12 h to obtain a modified reflective screen.

[0098] ④Arrange the 6 modified reflective screens prepared by the method in step ③ and the 5 fiber wet sheets obtained in step ① alternately. During the alternate arrangement, one of the fiber wet sheets is arranged between every two modified reflective screens. The high-temperature resistant phosphate binder obtained in step ② is coated on the surface of the fiber wet sheet in contact with the modified reflective screen. Control the coating thickness of the high-temperature resistant phosphate binder to be 90 μm. After molding under a pressure of 1 MPa for 60 min, then first cure at 90 °C for 6 h, and then raise the temperature to 150 °C and cure for 12 h to obtain a high-strength high-temperature resistant heat-insulating material.

[0099] Comparative Example 5

[0100] ①Weigh 90 parts of zirconia fiber (with a diameter of 8 μm) and 10 parts of zirconium carbide fiber (with a diameter of 5 μm), disperse them evenly in water to obtain a fiber slurry with a mass fraction of 1% (the sum of the mass fractions of zirconia fiber and zirconium carbide fiber contained in the fiber slurry is 1%). Pass the fiber slurry through a fourdrinier machine to make a fiber wet sheet with a thickness of 1 mm.

[0101] ② After mixing 7 parts of zirconium phosphate solid and 4 parts of magnesia (particle size 200 μm), place them in a ball mill and mill for 8 h to obtain a filler. Mix 22 parts of aluminum dihydrogen phosphate solution with a solid content of 40 wt% with the obtained filler and stir at 25 °C for 5 h to obtain a phosphate binder.

[0102] ③ Precoat the surface of the reflective screen (graphite paper with a thickness of 0.025 mm) that needs to be in contact with the fiber wet sheet with the phosphate binder obtained in step ②, control the coating thickness of the phosphate binder to be 90 μm, cure at 90 °C for 6 h first, and then raise the temperature to 150 °C and cure for 12 h to obtain a modified reflective screen.

[0103] ④ Alternately arrange 6 modified reflective screens prepared by the method in step ③ and 5 fiber wet sheets obtained in step ①. In the alternate arrangement, one of the fiber wet sheets is arranged between every two modified reflective screens. The surface of the fiber wet sheet in contact with the modified reflective screen is coated with the phosphate binder obtained in step ②, control the coating thickness of the phosphate binder to be 90 μm, after molding under a pressure of 1 MPa for 60 min, then cure at 90 °C for 6 h first, and then raise the temperature to 150 °C and cure for 12 h to obtain a heat-insulating material.

[0104] Comparative Example 6

[0105] ① Weigh 80 parts of zirconia fiber (diameter 3 μm) and 20 parts of zirconium carbide fiber (diameter 2 μm), disperse them evenly in water to obtain a fiber slurry with a mass fraction of 0.2% (the sum of the mass fractions of zirconia fiber and zirconium carbide fiber contained in the fiber slurry is 0.2%). Use a fourdrinier machine to make a fiber wet sheet with a thickness of 0.5 mm from the fiber slurry.

[0106] ② After mixing 6 parts of aluminum phosphate solid, 2 parts of magnesia (particle size 200 μm), 1 part of chromium oxide, and 1 part of spinel (particle size 20 μm), place them in a ball mill and mill for 8 h to obtain a filler. Mix 90 parts of aluminum dihydrogen phosphate solution with a solid content of 40 wt% with the obtained filler and stir for 20 min to disperse evenly, then add 5 parts of zirconium carbide whiskers (aspect ratio 100) and 3.5 parts of aluminum nitride fibers with a length of 8 μm, stir to disperse evenly, and then add 5 parts of magnesia powder and stir to disperse evenly to obtain a phosphate binder.

[0107] ③ Precoat the surface of the reflective screen (graphite paper with a thickness of 0.025 mm) that needs to be in contact with the fiber wet sheet with the phosphate binder obtained in step ②, control the coating thickness of the phosphate binder to be 30 μm, cure at 90 °C for 6 h first, and then raise the temperature to 150 °C and cure for 12 h to obtain a modified reflective screen.

[0108] ④ Alternately arrange the 11 modified reflective screens prepared by the method in step ③ and the 10 fiber wet sheets obtained in step ①. In the alternate arrangement, one of the fiber wet sheets is arranged between every two modified reflective screens. The surface of the fiber wet sheet in contact with the modified reflective screen is coated with the phosphate binder obtained in step ②. Control the coating thickness of the phosphate binder to be 30 μm. After molding under a pressure of 1 MPa for 60 min, first cure at 90 °C for 6 h, and then raise the temperature to 150 °C and cure for 12 h to obtain the thermal insulation material.

[0109] Comparative Example 7

[0110] ① Weigh 80 parts of zirconia fibers (diameter 3 μm) and 20 parts of zirconium carbide fibers (diameter 2 μm), disperse them evenly in water to obtain a fiber slurry with a mass fraction of 0.2% (the sum of the mass fractions of zirconia fibers and zirconium carbide fibers contained in the fiber slurry is 0.2%). Use a fourdrinier machine to make a fiber wet sheet with a thickness of 0.5 mm from the fiber slurry.

[0111] ② Mix 2 parts of magnesia (particle size 200 μm), 1 part of chromium oxide, and 1 part of spinel (particle size 20 μm), place them in a ball mill jar and ball mill for 8 h to obtain a filler. Mix 90 parts of an aluminum dihydrogen phosphate solution with a solid content of 40 wt% with the obtained filler, stir at 25 °C for 5 h to obtain a pre-crosslinked system. Then add 5 parts of zirconium carbide whiskers (aspect ratio 100) and 3.5 parts of aluminum nitride fibers with a length of 8 μm to the obtained pre-crosslinked system, stir and disperse evenly, and then add 5 parts of magnesia powder, stir and disperse evenly to obtain the phosphate binder.

[0112] ③ Precoat the surface of the reflective screen (graphite paper with a thickness of 0.025 mm) that needs to be in contact with the fiber wet sheet with the high-temperature resistant phosphate binder obtained in step ②. Control the coating thickness of the phosphate binder to be 30 μm. First cure at 90 °C for 6 h, and then raise the temperature to 150 °C and cure for 12 h to obtain the modified reflective screen.

[0113] ④ Alternately arrange the 11 modified reflective screens prepared by the method in step ③ and the 10 fiber wet sheets obtained in step ①. In the alternate arrangement, one of the fiber wet sheets is arranged between every two modified reflective screens. The surface of the fiber wet sheet in contact with the modified reflective screen is coated with the phosphate binder obtained in step ②. Control the coating thickness of the phosphate binder to be 30 μm. After molding under a pressure of 1 MPa for 60 min, first cure at 90 °C for 6 h, and then raise the temperature to 150 °C and cure for 12 h to obtain the high-strength high-temperature resistant thermal insulation material.

[0114] The present invention conducted performance tests on the heat-insulating materials finally prepared in each of the examples and each of the comparative examples. The results are shown in Table 1, where the compressive strength at 1500 °C and the compressive strength at 1800 °C both refer to the compressive strength when the heat-insulating material is compressed and damaged.

[0115] Table 1: Results of performance comparison of the heat-insulating materials prepared in each example and each comparative example

[0116]

[0117]

[0118] In Table 1, the symbol " / " indicates that the performance index was not tested.

[0119] The parts not detailed in the present invention are well-known technologies to those skilled in the art.

[0120] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing examples, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing examples, or perform equivalent replacements for some of the technical features. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A preparation method of a high-strength and high-temperature resistant heat insulation material, characterized in that, The method comprises the following steps: (1) Uniformly disperse zirconia fibers and zirconium carbide fibers with water to obtain a fiber slurry, and then form a wet fiber sheet by papermaking the fiber slurry; the sum of the mass percentages of zirconia fibers and zirconium carbide fibers in the fiber slurry is 0.2 - 3%; (2) Mix solid phosphate, magnesia, and chromium oxide and perform ball milling to obtain a filler, and then mix the phosphate solution with the filler and stir to obtain a high-temperature resistant phosphate binder; the stirring is carried out at room temperature for 3 - 6 h; (3) Coat the surface of the reflector screen with the high-temperature resistant phosphate binder and cure it to obtain a modified reflector screen; (4) Alternately arrange a plurality of the modified reflector screens and a plurality of the wet fiber sheets, and then perform molding and curing to obtain a high-strength and high-temperature resistant heat insulation material; in the alternate arrangement, one wet fiber sheet is arranged between every two modified reflector screens, and the surface of the wet fiber sheet is coated with the high-temperature resistant phosphate binder.

2. The preparation method according to claim 1, wherein: the diameter of the zirconia fibers is 3 - 10 μm, and the diameter of the zirconium carbide fibers is 2 - 5 μm; and / or the mass ratio of the zirconia fibers to the zirconium carbide fibers is (4 - 10):

1.

3. The preparation method according to claim 1, wherein: the thickness of the wet fiber sheet is 0.5 - 3 mm.

4. The preparation method according to claim 1, wherein: the mass ratio of the solid phosphate, the magnesia, and the chromium oxide is (6 - 13):(2 - 7):(1 - 3); the solid phosphate is solid aluminum phosphate and / or solid zirconium phosphate; the particle size of the magnesia is 10 - 200 μm; and / or the ball milling time is 6 - 12 h.

5. The preparation method according to claim 1, wherein: the solid content of the phosphate solution is 20 - 60 wt%; the mass ratio of the phosphate solution to the filler is (2 - 9):1; and / or the phosphate solution is one or more of aluminum dihydrogen phosphate solution, aluminum phosphate solution, and zirconium phosphate solution.

6. The preparation method according to claim 1, wherein: the thickness of the high-temperature resistant phosphate binder coated on the surface of the reflector screen is 30 - 90 μm; and / or the thickness of the high-temperature resistant phosphate binder coated on the surface of the wet fiber sheet is 30 - 90 μm.

7. The preparation method according to claim 1, wherein: in step (3) and / or step (4), the curing is as follows: first cure at 80 - 100 °C for 4 - 8 h, and then cure at 120 - 180 °C for 10 - 15 h.

8. The preparation method according to any one of claims 1 to 7, characterized in that, In step (2): the filler further contains spinel.

9. The preparation method according to claim 8, wherein: in the filler, the mass ratio of the solid phosphate, the magnesia, the chromium oxide, and the spinel is (6 - 13):(2 - 7):(1 - 3):(1 - 5).

10. The preparation method according to any one of claims 1 to 7, characterized in that, In step (2): After stirring, zirconium carbide whiskers and aluminum nitride fibers are further added and dispersed evenly, and then magnesium oxide powder is added and dispersed evenly to obtain the high-temperature resistant phosphate binder.

11. A high-strength and high-temperature resistant heat insulation material prepared by the preparation method according to any one of claims 1 to 10.

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