Anti-oxidation ablation-resistant chopped oxide fiber preform and molding preparation method thereof

Abstract

The invention relates to an anti-oxidation ablation-resistant chopped oxide fiber preform and a forming preparation method thereof, and belongs to the technical field of thermal insulation materials. The forming preparation method of the antioxidant ablation-resistant chopped oxide fiber preform comprises the following steps: mixing chopped oxide fibers, a multi-element ceramic component, a binder, an adsorbent, a water-soluble viscosity modifier and water, heating and stirring to obtain slurry; carrying out alcohol washing and filter pressing on the slurry to obtain a wet blank; and drying, curing and carbonizing the wet blank to obtain the antioxidant ablation-resistant chopped oxide fiber preform. According to the forming preparation method of the antioxidant ablation-resistant chopped oxide fiber preform, the density difference of raw materials can be overcome, and medium-density ceramic particles and low-density hollow ceramic microspheres are uniformly introduced into the high-density chopped oxide fiber preform; the light anti-oxidation ablation-resistant chopped oxide fiber preform with excellent performance is obtained.

Description

Technical Field

[0001] The invention relates to the technical field of heat-insulating materials, and in particular to an oxidation-resistant and ablation-resistant chopped oxide fiber preform and a molding preparation method thereof. Background Art

[0002] The oxide fiber preform is a fiberized network structure formed by the bonding of adjacent short-cut oxide fibers through intersections. It has the characteristics of low density, high porosity (and interconnected pores), low thermal conductivity, good high-temperature dimensional stability and chemical stability. It is suitable as a reinforcing phase for manufacturing thermal insulation materials and ablative materials, and has important uses in the military, defense, aviation, and aerospace industries.

[0003] Since oxide fibers, such as aluminum oxide and silicon oxide fibers, are generally polycrystalline or amorphous materials, during temperature fluctuations, the thermodynamically unstable crystal form is prone to transform into a high-temperature stable crystal form, resulting in a large volume effect, leading to fiber creep and embrittlement, making it difficult to maintain the mechanical properties of the composite material, and seriously restricting its long-term use at high temperatures (not less than 1000°C). In order to improve the high-temperature failure behavior of oxide fiber materials and improve the adaptability of materials in extreme environments, it is necessary to modify the composition and structure of oxide fiber preform materials.

[0004] From the perspective of engineering application, the most direct and effective method for preparing ablation-resistant oxide fiber preforms is the slurry modification method, which is to mix ceramic components (fibers, powders, etc.) with short oxide fibers into an aqueous slurry, which is filtered, dried, and solidified to form a porous preform. However, oxide fibers have a high density and ceramic powders have a low density. During the slurry preparation process, stratification and sedimentation are prone to occur, resulting in the ceramic components not being evenly dispersed inside the fiber preform. The modified fiber preform is prone to poor uniformity, high density, poor mechanical strength, and poor high-temperature service capability. Summary of the invention

[0005] In response to one or more technical problems existing in the prior art, the present invention provides an antioxidant and ablation-resistant chopped oxide fiber preform and a molding and preparation method thereof. The molding and preparation method of the antioxidant and ablation-resistant chopped oxide fiber preform provided by the present invention can overcome the difference in raw material density and achieve the uniform introduction of medium-density ceramic particles and low-density hollow ceramic microspheres into the interior of the high-density chopped oxide fiber preform, thereby obtaining a lightweight, antioxidant and ablation-resistant chopped oxide fiber preform with excellent performance.

[0006] The present invention provides a method for forming and preparing an oxidation-resistant and ablation-resistant chopped oxide fiber preform, characterized in that the preparation method comprises:

[0007] The chopped oxide fibers, the multi-component ceramic component, the binder, the adsorbent, the water-soluble viscosity modifier and water are mixed, and heated and stirred to obtain a slurry;

[0008] The slurry is subjected to alcohol washing and filter pressing to obtain a wet blank;

[0009] The wet blank is dried, solidified and carbonized to obtain an oxidation-resistant and ablation-resistant chopped oxide fiber preform.

[0010] Preferably, the amount of the ceramic component is 30-50% of the mass of the chopped oxide fibers;

[0011] The amount of the binder is 30-65% of the mass of the chopped oxide fibers; and / or

[0012] The amount of water used is 30 to 40 times the total mass of the chopped oxide fibers, the binder and the ceramic components.

[0013] Preferably, the chopped oxide fiber is at least one of chopped alumina fiber, chopped silica fiber, chopped mullite fiber, and chopped zirconia fiber;

[0014] The length of the chopped oxide fibers is 1 to 3 mm;

[0015] The multi-component ceramic components are at least two of silicon oxide hollow microspheres, silicon carbide powder, and zirconium boride powder; and / or

[0016] The binder includes phenolic resin, starch and glass fiber powder;

[0017] Preferably, the amount of the phenolic resin is 20-40% of the mass of the chopped oxide fibers;

[0018] The amount of starch used is 10-20% of the mass of the chopped oxide fibers; and / or

[0019] The amount of the glass fiber powder used is 20-30% of the mass of the chopped oxide fibers.

[0020] Preferably, the amount of the adsorbent is 0.5-1% of the mass of water; preferably, the adsorbent is polyethyleneimine.

[0021] Preferably, the amount of the water-soluble viscosity regulator is 0.1-0.25% of the mass of water; preferably, the water-soluble viscosity regulator is one or more of polyacrylamide, gelatin, guar gum, and carrageenan.

[0022] Preferably, the heating and stirring is carried out at a temperature of 40 to 70° C. and for a time of 1 to 2 hours.

[0023] Preferably, the amount of alcohol used in the alcohol washing process is 1.5 to 3 times the mass of water in the slurry; and / or

[0024] The pressure of the filter press is 50-200 kPa, and the time is 1-2 hours.

[0025] Preferably, the drying temperature is 60-80°C and the drying time is 24-72h;

[0026] The curing temperature is 150-200°C and the curing time is 2-4 hours; and / or

[0027] The carbonization temperature is 500-800° C. and the time is 2-4 hours.

[0028] The present invention provides an ablation-resistant quartz fiber skeleton in a second aspect, which is prepared by the preparation method described in the first aspect.

[0029] Compared with the prior art, the present invention has at least the following beneficial effects:

[0030] The present invention can make the surface of the short oxide fiber positively charged by adding an adsorbent to the slurry, and adsorb the binder and ceramic components with negative charges on the surface on and near the short oxide fiber surface. By adding a water-soluble viscosity modifier to the slurry, a huge gel-like network is formed between the short oxide fibers, the viscosity of the aqueous slurry is increased, the binder and ceramic powder are better stabilized around the short oxide fibers, and the binder and ceramic components are promoted to be uniformly adsorbed on the surface and overlap of the short oxide fibers. At the same time, the gel network formed by the water-soluble viscosity modifier can wrap other components together, thereby obtaining a slurry with uniform structure and composition, which can effectively solve the problem that the existing slurry method is prone to stratification and sedimentation due to the difference in density between the oxide fiber and the ceramic component, and cannot obtain a uniform slurry.

[0031] The present invention overcomes the difference in raw material density under the joint action of an adsorbent and a water-soluble viscosity regulator, blends medium and low density ceramic components with high-density chopped oxide fibers to obtain a fiber slurry with relatively uniform components, and during the alcohol washing process, a gel network formed by a water-soluble viscosity regulator that is not easily soluble in alcohol wraps other components to separate and settle from the slurry to obtain a co-precipitate containing chopped oxide fibers, multi-component ceramic components and a binder. The co-precipitate can be subjected to solid-liquid separation by filter pressing to obtain a wet blank with uniform distribution of each component, and finally, after drying, curing and carbonization, an antioxidant and ablation-resistant chopped oxide fiber preform with uniform distribution of multi-component ceramic components is obtained.

[0032] The molding and preparation method of the antioxidant and ablation-resistant short-cut oxide fiber preform of the present invention can overcome the difference in raw material density, and evenly introduce medium-density ceramic particles and low-density hollow ceramic microspheres into the interior of the high-density short-cut oxide fiber preform, thereby obtaining a lightweight antioxidant and ablation-resistant short-cut oxide fiber preform with excellent performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0034] Figure 1 is a comparison diagram of the slurry before and after alcohol washing in Example 6 of the present invention;

[0035] Figure 2 This is a physical picture of the slurry in Comparative Example 1 of the present invention;

[0036] Figure 3 This is a microscopic image of the oxidation-resistant and ablation-resistant chopped oxide fiber preform provided in Comparative Example 2 of the present invention;

[0037] Figure 4 This is a microscopic image of an oxidation-resistant and ablation-resistant chopped oxide fiber preform provided in Comparative Example 8 of the present invention;

[0038] Figure 5 These are macroscopic and microscopic images of the oxidation-resistant and ablation-resistant chopped oxide fiber preform provided in Example 4 of the present invention;

[0039] Figure 6 These are macroscopic and microscopic images of the oxidation-resistant and ablation-resistant chopped oxide fiber preform provided in Example 5 of the present invention;

[0040] Figure 7 These are macroscopic and microscopic images of the oxidation-resistant and ablation-resistant chopped oxide fiber preform provided in Example 6 of the present invention;

[0041] Figure 8 It is a macroscopic morphology of the oxidation-resistant and ablation-resistant chopped oxide fiber preform provided in Examples 4-6 of the present invention and Comparative Example 10 after being subjected to butane thermal testing (test conditions are 1100° C. treatment for 1800 s). DETAILED DESCRIPTION

[0042] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0043] The present invention provides a method for forming and preparing an oxidation-resistant and ablation-resistant chopped oxide fiber preform, characterized in that the preparation method comprises:

[0044] The chopped oxide fibers, the multi-component ceramic component, the binder, the adsorbent, the water-soluble viscosity modifier and water are mixed, and heated and stirred to obtain a slurry;

[0045] The slurry is subjected to alcohol washing and filter pressing to obtain a wet blank;

[0046] The wet blank is dried, solidified and carbonized to obtain an oxidation-resistant and ablation-resistant chopped oxide fiber preform.

[0047] The present invention can make the surface of the short oxide fiber positively charged by adding an adsorbent to the slurry, and adsorb the binder and ceramic components with negative charges on the surface on and near the short oxide fiber. By adding a water-soluble viscosity modifier to the slurry, a huge gel-like network is formed between the short oxide fibers, the viscosity of the aqueous slurry is increased, the binder and ceramic powder are better stabilized around the short oxide fibers, and the binder and ceramic components are uniformly adsorbed on the surface and overlap of the short oxide fibers. At the same time, the gel network formed by the water-soluble viscosity modifier can wrap other components together, thereby obtaining a slurry with uniform structure and composition, which can effectively solve the problem that the existing slurry method is prone to stratification and sedimentation due to the difference in density between the oxide fiber and the ceramic component, and cannot obtain a uniform slurry.

[0048] The present invention overcomes the difference in raw material density under the joint action of an adsorbent and a water-soluble viscosity regulator, blends medium and low density ceramic components with high-density chopped oxide fibers to obtain a fiber slurry with relatively uniform components, and during the alcohol washing process, a gel network formed by a water-soluble viscosity regulator that is not easily soluble in alcohol wraps other components to separate and settle from the slurry to obtain a co-precipitate containing chopped oxide fibers, multi-component ceramic components and a binder. The co-precipitate can be subjected to solid-liquid separation by filter pressing to obtain a wet blank with uniform distribution of each component, and finally, after drying, curing and carbonization, an antioxidant and ablation-resistant chopped oxide fiber preform with uniform distribution of multi-component ceramic components is obtained.

[0049] The molding and preparation method of the antioxidant and ablation-resistant short-cut oxide fiber preform of the present invention can overcome the difference in raw material density, and evenly introduce medium-density ceramic particles and low-density hollow ceramic microspheres into the interior of the high-density short-cut oxide fiber preform, thereby obtaining a lightweight antioxidant and ablation-resistant short-cut oxide fiber preform with excellent performance.

[0050] According to some preferred embodiments, the amount of the ceramic component is 30-50% of the mass of the chopped oxide fibers;

[0051] The amount of the binder is 30-65% of the mass of the chopped oxide fibers; and / or

[0052] The amount of water used is 30 to 40 times the total mass of the chopped oxide fibers, the binder and the ceramic components.

[0053] According to some preferred embodiments, the chopped oxide fibers are at least one of chopped alumina fibers, chopped silica fibers, chopped mullite fibers, and chopped zirconia fibers.

[0054] According to some preferred embodiments, the length of the chopped oxide fibers is 1 to 3 mm.

[0055] According to some preferred embodiments, the multi-component ceramic component is at least two of silicon oxide hollow microspheres, silicon carbide powder, and zirconium boride powder. The present invention introduces ceramic powder and ceramic hollow microspheres into the slurry to achieve uniform coating of ceramic powder on the surface of the oxide fiber preform and at the overlap points between fibers, and filling of lightweight and high-strength hollow microspheres in the fiber gaps. The two are evenly distributed in the oxide fiber preform, synergistically improving the material's anti-ablation ability.

[0056] According to some preferred embodiments, the binder includes phenolic resin, starch and glass fiber powder. The present invention uses a variety of binders such as starch, phenolic resin and glass fiber powder in combination, so that the material can maintain a good fiberized network structure from the slurry to the high-temperature service process, thereby obtaining an antioxidant and ablation-resistant chopped oxide fiber preform with excellent performance. The amount of phenolic resin accounts for 20-40% of the weight of the chopped oxide fiber, and is an important binder for the material in the dry blank state (after the wet blank is dried) and the finished product state, and can play a bonding role at 80-1000°C; the amount of glass fiber powder accounts for 20-30% of the weight of the chopped oxide fiber, and is an important binder for the material in the thermal assessment process, and can play a bonding role at 600-1200°C; the amount of starch accounts for 10-20% of the weight of the chopped oxide fiber, and is matched with the water-soluble viscosity regulator polyacrylamide, and is an important binder for the material in the slurry and wet blank state, and can play a bonding role at 20-200°C.

[0057] According to some preferred embodiments, the phenolic resin is used in an amount of 20-40% of the mass of the chopped oxide fibers.

[0058] According to some preferred embodiments, the amount of the starch used is 10-20% of the mass of the chopped oxide fibers.

[0059] According to some preferred embodiments, the amount of the glass fiber powder is 20-30% of the mass of the chopped oxide fibers.

[0060] According to some preferred embodiments, the amount of the adsorbent is 0.5-1% of the mass of water; preferably, the adsorbent is polyethyleneimine.

[0061] According to some preferred embodiments, the amount of the water-soluble viscosity regulator is 0.1-0.25% of the mass of water; preferably, the water-soluble viscosity regulator is one or more of polyacrylamide, gelatin, guar gum, carrageenan, preferably one or more of nonionic polyacrylamide, cationic polyacrylamide, anionic polyacrylamide.

[0062] According to some preferred embodiments, the temperature of the heating and stirring is 40 to 70° C., and the time is 1 to 2 hours. The present invention mixes chopped oxide fibers, multi-component ceramic components, binders, adsorbents, water-soluble viscosity regulators and water, and improves the dispersibility of multi-component ceramic components and binders on the surface of chopped oxide fibers and between chopped oxide fibers in the mixed solution by adjusting the amount of each component and heating and stirring, thereby obtaining a slurry with relatively uniform structure and composition.

[0063] According to some preferred embodiments, the amount of alcohol used in the alcohol washing process is 1.5 to 3 times the mass of water in the slurry. The present invention uses the alcohol washing process to allow the gel network formed by the water-soluble viscosity regulator to wrap other components and precipitate them from the slurry to obtain a coprecipitate in which each component is uniformly dispersed. The function of alcohol washing is to precipitate substances insoluble in alcohol and achieve solid-liquid separation of the slurry; alcohol is more volatile than water and requires a lower drying temperature; alcohol has a low surface tension and the chopped fiber products shrink less during the drying process. Solid-liquid separation can be achieved when the amount of alcohol used is 1.5 to 3 times the amount of water in the slurry; if the amount of alcohol used is too little, the alcohol is soluble in water and polyacrylamide cannot be precipitated; if the amount of alcohol used is too much, it will be wasted. The inventors found that if alcohol washing is not performed, a viscous slurry is obtained. After filter pressing, the slurry has no obvious change and solid-liquid separation cannot be achieved.

[0064] According to some preferred embodiments, the pressure of the filter press is 50 to 200 kPa, and the time is 1 to 2 hours.

[0065] According to some preferred embodiments, the drying temperature is 60 to 80° C. and the drying time is 24 to 72 hours.

[0066] According to some preferred embodiments, the curing temperature is 150-200° C. and the curing time is 2-4 hours.

[0067] According to some preferred embodiments, the carbonization temperature is 500-800° C. and the time is 2-4 hours.

[0068] It should be noted that phenolic resin is an alcohol-soluble substance. A small amount of loss will occur during the alcohol washing process, but it will not affect its overall curing and adsorption effects. While removing most of the solvent during the drying process, the phenolic resin is partially cured by heat and plays a bonding role. During the curing process, the phenolic resin is completely cured and the bonding block is strengthened. During the carbonization process, the small molecules and unstable groups in the skeleton are removed by reaction.

[0069] In a second aspect, the present invention provides an oxidation-resistant and ablation-resistant chopped oxide fiber preform, which is prepared by the preparation method described in the first aspect.

[0070] The oxidation-resistant and ablation-resistant chopped oxide fiber preform provided by the present invention has ceramic components evenly distributed on the surface, at the overlapping points between fibers and in the fiber gaps, which can improve the temperature resistance of the fiber skeleton, maintain a good fiberization network structure under high temperature, and has excellent ablation resistance.

[0071] The density of the oxidation-resistant and ablation-resistant chopped oxide fiber preform provided by the present invention does not exceed 0.5 g / cm 3 The room temperature Z-direction compressive strength can reach 1.6MPa, and the room temperature Z-direction thermal conductivity does not exceed 0.049W·m -1 ·K -1 After 900s in a muffle furnace at 1000℃, the compression strength retention rate is above 60%, and after 1800s in butane ablation at 1100℃, the linear ablation rate can be as low as 3.61×10 - 3 mm·s -1 , the mass ablation rate can be as low as 2.41×10 -3 g·s -1 .

[0072] In order to more clearly illustrate the technical solutions and advantages of the present invention, the present invention is further described below in conjunction with the examples. The present invention does not specifically limit the sources of the reagents used in the examples and comparative examples, and the reagents can be directly purchased or synthesized by themselves.

[0073] Example 1

[0074] (1) Polyethyleneimine and deionized water are mixed and stirred thoroughly to obtain a polyethyleneimine aqueous solution, i.e., solution A; nonionic polyacrylamide is mixed with deionized water, and heated and stirred in a water bath at 60° C. to obtain a polyacrylamide aqueous solution, i.e., solution B; short-cut alumina fiber, phenolic resin powder, starch, glass fiber powder, zirconium boride powder, and silicon carbide powder are then added to solution A in sequence, stirred evenly, and then an appropriate amount of solution B is added to obtain a mixed solution, and the mixed solution is heated in a water bath at 60° C. at a stirring speed of 300 r / min, and kept warm for 1 hour to obtain a slurry; wherein the mass ratio of deionized water, polyethyleneimine, nonionic polyacrylamide, short-cut alumina fiber, starch, phenolic resin powder, glass fiber powder, zirconium boride powder, and silicon carbide powder is 700:5:1:10:1:3:2:1:2.

[0075] (2) The obtained slurry was mixed with ethanol (the amount of ethanol was twice the mass of deionized water in the slurry) and stirred at a stirring speed of 150 r / min for 30 min. The precipitated blend was fished out and transferred into a filter press mold, pressurized to 100 kPa and maintained at this pressure for 2 h to obtain a wet blank.

[0076] (3) placing the sealed mold containing the wet blank in a 70°C oven for drying for 40 hours, and demolding to obtain a dry blank; curing the obtained dry blank, the curing procedure is to heat the temperature to 150°C at a heating rate of 5°C / min and cure for 3 hours, after which a multi-component ceramic-modified alumina fiber preform is obtained; placing the multi-component ceramic-modified alumina fiber preform in an argon atmosphere for carbonization, the carbonization procedure is to heat the temperature to 800°C at a heating rate of 5°C / min and keep the temperature for 3 hours, to obtain an oxidation-resistant and ablation-resistant short-cut oxide fiber preform.

[0077] Examples 2-6 of the present invention are substantially the same as Example 1, with the differences being as shown in Table 1 below.

[0078] Table 1. Comparison of parameters in the preparation process of Examples 1-6 of the present invention

[0079]

[0080] Note: The amount of ethanol in the table is the multiple of the mass of ethanol and the mass of deionized water in the slurry.

[0081] Depend on Figure 1 It can be seen that the components in the slurry obtained after dispersion in Example 6 are uniformly dispersed, and after washing with alcohol, a coprecipitate in which the components are uniformly dispersed can be formed. It should be noted that Examples 2-6 of the present invention can all obtain Figure 1 Slurries and co-precipitates with similar morphologies are not described in detail here.

[0082] Comparative Example 1

[0083] The method is basically the same as Example 6, except that polyethyleneimine and nonionic polyacrylamide are not added.

[0084] like Figure 2 As shown, due to the lack of addition of polyethyleneimine and non-ionic polyacrylamide, the ceramic components and fibers were severely stratified during the dispersion process. The top floating material was hollow silica microspheres, and the bottom precipitate was chopped alumina fibers and chopped silica fibers. No co-precipitate could be formed by alcohol washing.

[0085] Comparative Example 2

[0086] It is basically the same as Example 6, except that the mass ratio of deionized water, polyethyleneimine, non-ionic polyacrylamide, chopped alumina fibers, chopped silica fibers, phenolic resin, starch, glass fiber powder, zirconium boride, silicon carbide, and hollow silica microspheres is 1500:1:2.5:12:8:6:2:3:3:3:2.

[0087] like Figure 3 As shown, the amount of polyethyleneimine used in this comparative example is too small, resulting in poor adsorption of the ceramic component and an insignificant modification effect. From the electron microscope image, it can be seen that only a very small amount of ceramic components are adsorbed on the fiber surface and the fiber overlap in the final fiber preform, and the ceramic components are agglomerated.

[0088] Comparative Example 3

[0089] It is basically the same as Example 6, except that the mass ratio of deionized water, polyethyleneimine, non-ionic polyacrylamide, chopped alumina fibers, chopped silica fibers, phenolic resin, starch, glass fiber powder, zirconium boride, silicon carbide, and silica hollow microspheres is 1500:10:0.5:12:8:6:2:3:3:3:2.

[0090] In this comparative example, since the amount of nonionic polyacrylamide used was too small, during the dispersion process, although the ceramic components and fibers did not obviously agglomerate, the slurry was stratified, and no coprecipitate could be formed by alcohol washing.

[0091] Comparative Example 4

[0092] It is basically the same as Example 6, except that the mass ratio of deionized water, polyethyleneimine, non-ionic polyacrylamide, chopped alumina fibers, chopped silica fibers, phenolic resin, starch, glass fiber powder, zirconium boride, silicon carbide, and hollow silica microspheres is 1500:10:5:12:8:6:2:3:3:3:2.

[0093] In this comparative example, due to excessive use of non-ionic polyacrylamide, multiple "dough-like" flocs are formed during the alcohol washing process, and the ceramics and fibers are unevenly distributed; the shape is difficult to control during the solidification process.

[0094] Comparative Example 5

[0095] It is basically the same as Example 6, except that the mass ratio of deionized water, polyethyleneimine, non-ionic polyacrylamide, chopped alumina fibers, chopped silica fibers, phenolic resin, starch, glass fiber powder, zirconium boride, silicon carbide, and silica hollow microspheres is 1500:10:2.5:12:8:6:0:3:3:3:2.

[0096] In this comparative example, since starch was not added, the slurry formed had poor integrity after alcohol washing, and a large amount of ceramic components were lost during the filter pressing process.

[0097] Comparative Example 6

[0098] It is basically the same as Example 6, except that the mass ratio of deionized water, polyethyleneimine, non-ionic polyacrylamide, chopped alumina fibers, chopped silica fibers, phenolic resin, starch, glass fiber powder, zirconium boride, silicon carbide, and hollow silica microspheres is 1500:10:2.5:12:8:6:5:3:3:3:2.

[0099] In this comparative example, due to the excessive amount of starch added, uncontrollable sedimentation of the components occurred during the slurry preparation process, resulting in poor dispersion uniformity of the components in the slurry. Although a co-precipitate can be formed after alcohol washing, only a very small amount of ceramic components is adsorbed on the fiber surface and the fiber overlap, that is, most of the ceramic components and fibers are precipitated separately, and the components are not evenly distributed.

[0100] Comparative Example 7

[0101] It is basically the same as Example 6, except that the mass ratio of deionized water, polyethyleneimine, non-ionic polyacrylamide, chopped alumina fiber, chopped silica fiber, phenolic resin, starch, glass fiber powder, zirconium boride, silicon carbide, and silica hollow microspheres is 1500:10:2.5:12:8:2:2:3:3:3:2.

[0102] Since the amount of phenolic resin used in this comparative example is too small, insufficient bonding occurs after curing, powdering easily occurs, and the structure is easily destroyed.

[0103] Comparative Example 8

[0104] It is basically the same as Example 6, except that the mass ratio of deionized water, polyethyleneimine, non-ionic polyacrylamide, chopped alumina fiber, chopped silica fiber, phenolic resin, starch, glass fiber powder, zirconium boride, silicon carbide, and silica hollow microspheres is 1500:10:2.5:12:8:10:2:3:3:3:2.

[0105] This comparative example uses too much phenolic resin, which causes excessive bonding, density, and hardening after curing. Figure 4 As shown, in the final fiber preform, only a very small amount of ceramic components are adsorbed on the fiber surface and the fiber overlap, and a large amount of phenolic resin is adsorbed on the fiber surface and the fiber overlap, blocking the pores and affecting the thermal insulation performance.

[0106] Comparative Example 9

[0107] It is basically the same as Example 6, except that the mass ratio of deionized water, polyethyleneimine, non-ionic polyacrylamide, chopped alumina fibers, chopped silica fibers, phenolic resin, starch, glass fiber powder, zirconium boride, silicon carbide, and silica hollow microspheres is 1500:0.23:0.31:12:8:6:2:3:3:3:2.

[0108] In this comparative example, since the dosage of polyethyleneimine and nonionic polyacrylamide is too small, the ceramic components and fibers in the formed slurry are agglomerated, and the slurry is stratified; and no coprecipitate can be formed by alcohol washing.

[0109] Comparative Example 10

[0110] It is basically the same as Example 6, except that no ceramic components (zirconium boride, silicon carbide and silicon oxide hollow microspheres) are added.

[0111] Comparative Example 11

[0112] The method is basically the same as Example 6, except that the slurry in step (1) is directly subjected to filter pressing without alcohol washing.

[0113] The step (1) obtains a viscous slurry, which undergoes no significant change after filter pressing, and thus solid-liquid separation cannot be achieved.

[0114] like Figure 5 As shown, in the oxidation-resistant and ablation-resistant chopped oxide fiber preform obtained in Example 4, the chopped alumina fibers represented by aluminum (Al) are effectively bonded at the overlap by phenolic resin represented by carbon (C) and glass fiber powder represented by silicon (Si), and the two are bonded in a point shape of about 100um. The surface and overlap of the alumina fibers are filled with silicon carbide powder represented by silicon (Si) and zirconium boride powder represented by zirconium (Zr), and the distribution scale of the two does not exceed 50um.

[0115] like Figure 6As shown, in the oxidation-resistant and ablation-resistant chopped oxide fiber preform obtained in Example 5, the chopped alumina fibers represented by aluminum (Al) are effectively bonded at the overlap by phenolic resin represented by carbon (C) and glass fiber powder represented by silicon (Si), and the two are bonded in a point shape of about 100um. The surface and overlap of the alumina fibers are filled with silicon carbide powder represented by silicon (Si), hollow silicon oxide microspheres, and zirconium boride powder represented by zirconium (Zr), and the distribution scale of the three does not exceed 50um.

[0116] like Figure 7 As shown, in the oxidation-resistant and ablation-resistant chopped oxide fiber preform obtained in Example 6, the chopped alumina fibers represented by aluminum (Al) and the chopped silica fibers represented by silicon (Si) are effectively bonded at the overlap by phenolic resin represented by carbon (C) and glass fiber powder represented by silicon (Si), and the two are point-bonded at about 100um. The surfaces and overlaps of the alumina fibers and silica fibers are filled with silicon carbide powder represented by silicon (Si), hollow silica microspheres, and zirconium boride powder represented by zirconium (Zr), and the distribution scale of the three does not exceed 50um.

[0117] Depend on Figure 8 It can be seen that the oxidation-resistant and ablation-resistant short-cut oxide fiber preforms (all with dimensions of 80 mm (length) × 80 mm (width) × 20 mm (height)) obtained in Examples 4-6 of the present invention have a smooth surface after butane thermal testing, without large-scale powdering, indicating that the addition of ceramic components greatly improves the shape-keeping ability and heat-resistant ability of the fiber skeleton at high temperatures. The oxidation-resistant and ablation-resistant short-cut oxide fiber preform of Comparative Example 10 decomposed and powdered layer by layer during the testing process, and the surface was damaged in a large area, indicating that the oxide fiber preform without the introduction of ceramic components is difficult to resist the erosion of heat flow and maintain its own structure intact and stable performance.

[0118] The performance data of the oxidation-resistant and ablation-resistant chopped oxide fiber preform of the embodiment of the present invention are shown in Table 2, and the testing methods of various performance data all adopt the general testing methods in the art.

[0119] Table 2. Performance data of the oxidation-resistant and ablation-resistant chopped oxide fiber preform of the embodiment of the present invention

[0120]

[0121]

[0122] It should be noted that the test conditions for the line ablation rate and mass ablation rate in the table are 1100°C treatment for 1800s, and the compressive strength retention rate is obtained after treatment at 1000°C for 900s.

[0123] It can be seen from Table 1 that the density of the oxidation-resistant and ablation-resistant chopped oxide fiber preform provided by the embodiment of the present invention does not exceed 0.50 g / cm 3 The room temperature Z-direction compressive strength can reach 1.6MPa, and the room temperature Z-direction thermal conductivity does not exceed 0.049W·m -1 ·K -1 After 900s in a muffle furnace at 1000℃, the compression strength retention rate is above 60%, and after 1800s in butane ablation at 1100℃, the linear ablation rate can be as low as 3.61×10 -3 mm·s -1 , the mass ablation rate can be as low as 2.41×10 -3 g·s -1 .

[0124] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for forming and preparing an oxidation-resistant and ablation-resistant chopped oxide fiber preform, characterized in that: The preparation method comprises: The chopped oxide fibers, the multi-component ceramic component, the binder, the adsorbent, the water-soluble viscosity modifier and water are mixed, and heated and stirred to obtain a slurry; The slurry is subjected to alcohol washing and filter pressing to obtain a wet blank; The wet blank is dried, solidified and carbonized to obtain an oxidation-resistant and ablation-resistant chopped oxide fiber preform.

2. The preparation method according to claim 1, characterized in that: The amount of the ceramic component is 30-50% of the mass of the chopped oxide fibers; The amount of the binder is 30-65% of the mass of the chopped oxide fibers; and / or The amount of water used is 30 to 40 times the total mass of the chopped oxide fibers, the binder and the ceramic components.

3. The preparation method according to claim 1, characterized in that: The chopped oxide fibers are at least one of chopped alumina fibers, chopped silica fibers, chopped mullite fibers, and chopped zirconia fibers; The length of the chopped oxide fibers is 1 to 3 mm; The multi-component ceramic components are at least two of silicon oxide hollow microspheres, silicon carbide powder, and zirconium boride powder; and / or The binder comprises phenolic resin, starch and glass fiber powder.

4. The preparation method according to claim 3, characterized in that: The amount of the phenolic resin is 20-40% of the mass of the chopped oxide fibers; The amount of starch used is 10-20% of the mass of the chopped oxide fibers; and / or The amount of the glass fiber powder used is 20-30% of the mass of the chopped oxide fibers.

5. The preparation method according to claim 1, characterized in that: The amount of the adsorbent used is 0.5-1% of the mass of water; preferably, the adsorbent is polyethyleneimine.

6. The preparation method according to claim 1, characterized in that: The amount of the water-soluble viscosity regulator is 0.1-0.25% of the mass of water; preferably, the water-soluble viscosity regulator is one or more of polyacrylamide, gelatin, guar gum, and carrageenan.

7. The preparation method according to claim 1, characterized in that: The heating and stirring is performed at a temperature of 40 to 70° C. and for a time of 1 to 2 hours.

8. The preparation method according to claim 1, characterized in that: The amount of alcohol used in the alcohol washing process is 1.5 to 3 times the mass of water in the slurry; and / or The pressure of the filter press is 50-200 kPa, and the time is 1-2 hours.

9. The preparation method according to claim 1, characterized in that: The drying temperature is 60-80°C and the drying time is 24-72h; The curing temperature is 150-200°C and the curing time is 2-4 hours; and / or The carbonization temperature is 500-800° C. and the time is 2-4 hours.

10. An ablation-resistant quartz fiber skeleton, characterized in that: The method is prepared by the method according to any one of claims 1 to 9.

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