SiZrOC thermal insulation ceramic material and preparation method thereof

Abstract

The invention provides a SiZrOC thermal insulation ceramic material and a preparation method thereof, and relates to the technical field of thermal insulation materials. The preparation method comprises the following steps: mixing a zirconium source solution and a silicon source solution to obtain a photosensitive solution; wherein the zirconium source solution contains carbon-carbon double bonds, and the silicon source solution contains sulfydryl and carbon-carbon double bonds; performing ultraviolet radiation on the photosensitive solution to enable carbon-carbon double bonds in the photosensitive solution to react with sulfydryl, and performing molding treatment to obtain a precursor blank; and carrying out heat treatment on the precursor blank to obtain the SiZrOC thermal insulation ceramic material. Under the action of ultraviolet light, a mercapto-alcohol click reaction can be induced to enable the photosensitive solution to be crosslinked and cured, and then C and groups and the like which cannot be maintained at high temperature are removed through heat treatment, so that the SiZrOC heat insulation ceramic material is obtained, long-time and complex aging and low-temperature heat treatment are not needed, the preparation period is greatly shortened, and the preparation cost is reduced. The preparation efficiency of the SiZrOC heat insulation ceramic material is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of thermal insulation materials, and specifically relates to a SiZrOC thermal insulation ceramic material and a preparation method thereof. Background Art

[0002] With the rapid development of the aerospace industry, the demand for thermally stable and efficient thermal insulation materials in aircraft is increasing, and high-temperature stable thermal insulation materials have become the focus of materials in the above fields. Silicon oxygen carbon (SiOC) ceramics are a kind of thermal insulation material with an amorphous structure. It can be regarded as a product in which some oxygen atoms in the SiO2 network are replaced by carbon atoms. It has the characteristics of low density, low thermal conductivity, low thermal expansion coefficient, and high temperature stability. It is a good lightweight and high temperature resistant material.

[0003] However, SiOC ceramic materials will undergo phase decomposition and carbon thermal reaction above 1250°C, resulting in the destruction of the amorphous structure and the precipitation of silicon dioxide, silicon carbide and other grains, which reduces its high-temperature stability and makes it impossible to use it for thermal insulation in higher temperature ranges. Stabilizing the SiOC amorphous network is an effective way to improve its thermal stability.

[0004] At present, the high-temperature stability of SiOC ceramic materials can be improved by adding elements with high melting points and high thermal stability. The introduction of heterogeneous elements into siloxane polymers changes the phase separation and crystallization behavior of SiOC, thereby improving its high-temperature stability and increasing its application temperature range. The way in which heterogeneous elements are added will affect the existence form of the elements, thereby affecting the high-temperature stability of element-doped SiOC-based ceramic materials. The traditional sol-gel method of adding heterogeneous elements requires long and complex aging and low-temperature heat treatment. During the aging process, the colloid particles further aggregate and reorganize, slowly polymerize, and form a more stable and uniform three-dimensional network structure. This process includes not only the formation and reorganization of chemical bonds, but also the evaporation of solvents and the consumption of water. These changes require a certain amount of time to complete to ensure that the network structure of the gel is stable and uniform, so it is not conducive to the rapid preparation of SiOC ceramics, and this method is difficult to achieve the preparation of complex structural components.

[0005] In summary, existing ceramic thermal insulation materials have the following problems: the preparation process is complex and the preparation cycle is long, the high-temperature stability is poor, and it is difficult to prepare components with complex structures. Summary of the invention

[0006] Therefore, the present invention provides a SiZrOC thermal insulation ceramic material and a preparation method thereof to solve the problems of complex preparation process and long preparation cycle of existing ceramic thermal insulation materials.

[0007] In order to solve the above problems, the present invention provides a method for preparing a SiZrOC thermal insulation ceramic material, comprising the following steps:

[0008] Step 1) mixing a zirconium source solution and a silicon source solution to obtain a photosensitive solution; wherein the zirconium source solution contains a carbon-carbon double bond, and the silicon source solution contains a thiol group and a carbon-carbon double bond;

[0009] Step 2) subjecting the photosensitive solution to ultraviolet radiation so that the carbon-carbon double bonds in the photosensitive solution react with the thiol groups, and simultaneously subjecting the photosensitive solution to a molding process to obtain a precursor body;

[0010] Step 3) heat-treating the precursor body to obtain SiZrOC thermal insulation ceramic material.

[0011] Furthermore, in the step 1), the method further comprises the step of preparing the zirconium source solution: mixing zirconium n-propoxide with acrylic acid, and then treating the mixture in an ice-water bath to obtain a zirconium source solution;

[0012] Preferably, the molar ratio of zirconium n-propoxide to acrylic acid is 1:1-4;

[0013] Preferably, the temperature of the ice water bath treatment is 0-6°C;

[0014] Preferably, the ice water bath treatment time is 4-6 hours.

[0015] Furthermore, in the step 1), the method further comprises the step of preparing the silicon source solution: mixing a Si-containing organic substance containing multiple thiol groups, a Si-containing organic substance containing multiple vinyl groups, a photoinitiator, and a free radical scavenger to obtain a silicon source solution;

[0016] Preferably, the molar ratio of thiol to vinyl in the photosensitive solution is 1:0.5-3;

[0017] Preferably, the Si-containing organic compound containing multiple thiol groups is a Si-containing oligomer containing multiple thiol groups or a Si-containing monomer containing multiple thiol groups;

[0018] Preferably, the Si-containing organic compound containing multiple vinyl groups is a Si-containing oligomer containing multiple vinyl groups or a Si-containing monomer containing multiple vinyl groups;

[0019] Preferably, the average molecular weight of the Si-containing organic compound containing multiple thiol groups is 200-8000;

[0020] Preferably, the Si-containing organic compound containing multiple mercapto groups is one or more of (mercapto)methylsiloxane-dimethylsiloxane copolymer, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, and (mercaptopropyl)methylsiloxane copolymer;

[0021] Preferably, the average molecular weight of the Si-containing organic compound containing multiple vinyl groups is 200-8000;

[0022] Preferably, the Si-containing organic compound containing multiple vinyl groups is one or more of a block copolymer of dimethylsiloxane and diphenylsiloxane, vinyl polydimethylsiloxane, vinyl-terminated polyphenylsiloxane, vinyl methoxysiloxane copolymer, and methyl-vinyl (siloxane and polysiloxane).

[0023] Furthermore, in the step 1):

[0024] In the photosensitive solution, the molar ratio of zirconium element in the zirconium source solution to silicon element in the silicon source solution is 0.01-0.35:1.

[0025] Furthermore, in the step of preparing the silicon source solution:

[0026] The photoinitiator is one or more of 2-hydroxy-2-methyl-1-phenylpropanone, 1-hydroxycyclohexylphenyl ketone, 2-methyl-2-(4-morpholinyl)-1-[4-(methylthio)phenyl]-1-propanone, and phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide; and / or

[0027] The free radical scavenger is one or more of 2,6-di-tert-butyl-p-methylphenol, bis(1,2,2,6,6-pentamethylpiperidinol) sebacate, dimethylbenzene dibutylbenzofuranone, and 2,2,6,6-tetramethylpiperidinyl nitrogen oxide.

[0028] Furthermore, in the photosensitive solution, the mass fraction of the photoinitiator is 0.05-2%, and the mass fraction of the free radical scavenger is 0.05-2%.

[0029] Further, in the step 2):

[0030] The wavelength of ultraviolet light during ultraviolet irradiation is 365-405nm; and / or

[0031] The photosensitive solution is molded by using DLP additive manufacturing technology;

[0032] The parameters of DLP additive manufacturing are set as follows: layer thickness is 40-200μm, and exposure intensity is set to 1-100mW / cm 2 , the exposure time is set to 0.5-30s.

[0033] Furthermore, in step 3), the step of heat treating the precursor body includes:

[0034] In an inert atmosphere, the precursor body is heated to 800-1000° C., kept at this temperature for 0.5-10 hours, and then cooled to room temperature;

[0035] Preferably, the inert atmosphere is argon;

[0036] Preferably, the rate of heating the precursor body is 0.5-10°C / min;

[0037] Preferably, the precursor body is cooled at a rate of 1-5°C / min.

[0038] On the other hand, the present invention provides a SiZrOC thermal insulation ceramic material, wherein the structure of the SiZrOC thermal insulation ceramic material is a simulated lattice structure; the SiZrOC thermal insulation ceramic material comprises an amorphous structure and ZrO2 crystals;

[0039] Preferably, the ZrO2 crystals are dispersed in the amorphous structure; the grain size of the ZrO2 crystals is less than 3 nm.

[0040] Furthermore, the heat-resistant temperature of the SiZrOC thermal insulation ceramic material is: 200-1600°C under inert gas conditions and 200-1400°C under air conditions; the thermal insulation efficiency of the SiZrOC thermal insulation ceramic material is 65%-75% at 800°C; the compressive strength of the SiZrOC thermal insulation ceramic material is 3-8MPa;

[0041] Preferably, the SiZrOC thermal insulation ceramic material is obtained by any of the preparation methods described above. The SiZrOC thermal insulation ceramic material and the preparation method thereof provided by the present invention have the following beneficial effects:

[0042] 1. The present invention obtains a photosensitive solution by mixing a zirconium source solution with a silicon source solution; wherein the zirconium source solution contains a carbon-carbon double bond, and the silicon source solution contains a thiol and a carbon-carbon double bond; then, the photosensitive solution is additively manufactured under ultraviolet light so that the carbon-carbon double bonds in the photosensitive solution react with the thiol to obtain a precursor body; the obtained precursor body is heat-treated to obtain a SiZrOC thermal insulating ceramic material; compared with the "sol-gel method" for preparing SiZrOC thermal insulating ceramic materials in the prior art, the above method of the present application can induce a thiol click reaction under the action of ultraviolet light, so that the carbon-carbon double bonds in the photosensitive solution react with the thiol, cross-linking to form a highly polymerized network structure, and then the precursor is ceramicized by heat treatment at a certain temperature to obtain a SiZrOC thermal insulating ceramic material, so there is no need for long and complicated aging and low-temperature heat treatment, which greatly shortens the preparation cycle and improves the preparation efficiency of the SiZrOC thermal insulating ceramic material.

[0043] 2. Furthermore, the present invention heat treats the precursor body to form an amorphous structure after decarburization and deoxidation of SiZrOC, and adds a suitable proportion of zirconium elements through a mercaptan click reaction to balance the relationship between amorphous and crystalline, thereby forming a unique SiZrOC thermal insulation ceramic material combining amorphous SiZrOC matrix, amorphous ZrO2 and nano ZrO2 particles (crystals), wherein nano ZrO2 particles (crystals) with a grain size of less than 3nm are dispersed in the amorphous. In a high temperature environment, the precipitation and crystallization of zirconium dioxide can absorb energy, and at the same time can form pinning sites in the amorphous matrix, which can effectively inhibit the crystallization of amorphous SiZrOC, thereby improving the thermal stability of the material.

[0044] 3. Furthermore, the present invention adopts additive manufacturing to perform molding processing on the photosensitive solution. On the one hand, it can prepare SiZrOC thermal insulation ceramic materials with high precision and complex structures; on the other hand, it can effectively reduce the weight of the ceramic thermal insulation materials.

[0045] 4. On the other hand, the present invention provides a SiZrOC thermal insulation ceramic material prepared by the above method; the heat-resistant temperature of the SiZrOC thermal insulation ceramic material is: 200-1600°C under inert gas conditions and 200-1400°C under air conditions; the thermal insulation efficiency of the SiZrOC thermal insulation ceramic material is 65%-75% at 800°C; the compressive strength of the SiZrOC thermal insulation ceramic material is 3-8MPa. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the implementation methods of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the implementation methods or the description of the prior art. The drawings described below are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0047] Figure 1 The precursor additive manufacturing reaction principle of the SiZrOC thermal insulation ceramic material prepared in Example 1;

[0048] Figure 2 The precursor and ceramic physical picture of the SiZrOC thermal insulation ceramic material prepared in Example 1;

[0049] Figure 3 This is a graph showing the test results of the SiZrOC thermal insulation ceramic material prepared in Example 1 at 800°C back temperature;

[0050] Figure 4 XRD results of the SiZrOC thermal insulation ceramic materials prepared in Example 1 and Example 2 after heat treatment at 1200 to 1400° C. for 6 hours in an oxygen environment;

[0051] Figure 5 This is a SEM microscopic morphology of the SiZrOC thermal insulation ceramic material prepared in Example 2;

[0052] Figure 6 This is a graph showing the test results of the SiZrOC thermal insulation ceramic material prepared in Example 3 at 800°C back temperature;

[0053] Figure 7 This is a SEM microscopic morphology of the SiZrOC thermal insulation ceramic material prepared in Example 4;

[0054] Figure 8 HRTEM of the SiZrOC thermal insulation ceramic material prepared in Example 5 after heat treatment at 1600°C for 6 hours in an inert environment. DETAILED DESCRIPTION

[0055] In order to more clearly illustrate the implementation methods of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the implementation methods or the description of the prior art. The drawings described below are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0056] The present invention provides a method for preparing a SiZrOC thermal insulation ceramic material, comprising the following steps:

[0057] Step 1) mixing a zirconium source solution and a silicon source solution to obtain a photosensitive solution; wherein the zirconium source solution contains a carbon-carbon double bond and the silicon source solution contains a thiol group;

[0058] wherein zirconium n-propoxide and acrylic acid are mixed and then treated in an ice-water bath to obtain a zirconium source solution; preferably, the molar ratio of zirconium n-propoxide to acrylic acid is 1:1-4; preferably, the temperature of the ice-water bath treatment is 0-6°C; preferably, the time of the ice-water bath treatment is 4-6 hours; wherein, magnetic stirring is performed at a speed of 300-600 rpm during the ice-water bath treatment to promote the chelation of zirconium n-propoxide and acrylic acid to form zirconium acrylate;

[0059] A Si-containing organic matter containing multiple thiol groups, a Si-containing organic matter containing multiple vinyl groups, a photoinitiator, and a free radical scavenger are mixed to obtain a silicon source solution; in the photosensitive solution, the molar ratio of zirconium element in the zirconium source solution to silicon element in the silicon source solution is 0.01-0.35:1; the molar ratio of thiol group to vinyl group in the photosensitive solution is 1:0.5-3 (wherein, the silicon source solution contains thiol group, and both the zirconium source solution and the silicon source solution contain vinyl group); in the photosensitive solution, the mass fraction of the photoinitiator is 0.05-2%, and the mass fraction of the free radical scavenger is 0.05-2%;

[0060] Step 2) Under ultraviolet light, the photosensitive solution is molded by using DLP additive manufacturing technology (i.e., the photosensitive solution is exposed and molded layer by layer) so that the carbon-carbon double bonds in the zirconium source solution react with the thiol groups in the silicon source solution to obtain a precursor blank;

[0061] The wavelength of ultraviolet light during ultraviolet irradiation is 365-405nm; DLP refers to digital light processing, and the parameters of DLP additive manufacturing are set as follows: layer thickness is 40-200μm, and exposure intensity is set to 1-100mW / cm 2 , the exposure time is set to 0.5-30s;

[0062] Step 3) heat treating the precursor body to obtain SiZrOC thermal insulation ceramic material;

[0063] The step of heat treating the precursor body comprises: heating the precursor body to 800-1000° C. in an inert atmosphere, keeping the temperature for 0.5-10 hours, and then cooling the temperature to room temperature;

[0064] Preferably, the inert atmosphere is argon; preferably, the rate of heating the precursor body is 0.5-10°C / min; preferably, the rate of cooling the precursor body is 1-5°C / min.

[0065] In some embodiments, the Si-containing organic compound containing multiple thiol groups is a Si-containing oligomer containing multiple thiol groups or a Si-containing monomer containing multiple thiol groups; and / or

[0066] The Si-containing organic substance containing multiple vinyl groups is a Si-containing oligomer containing multiple vinyl groups or a Si-containing monomer containing multiple vinyl groups;

[0067] Preferably, the average molecular weight of the Si-containing organic compound containing multiple thiol groups is 200-8000;

[0068] Preferably, the Si-containing organic compound containing multiple mercapto groups is one or more of (mercapto)methylsiloxane-dimethylsiloxane copolymer, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, and (mercaptopropyl)methylsiloxane copolymer;

[0069] Preferably, the average molecular weight of the Si-containing organic compound containing multiple vinyl groups is 200-8000;

[0070] Preferably, the Si-containing organic compound containing multiple vinyl groups is one or more of a block copolymer of dimethylsiloxane and diphenylsiloxane, vinyl polydimethylsiloxane, vinyl-terminated polyphenylsiloxane, vinyl methoxysiloxane copolymer, and methyl-vinyl (siloxane and polysiloxane).

[0071] In some embodiments, the photoinitiator is one or more of 2-hydroxy-2-methyl-1-phenylpropanone, 1-hydroxycyclohexylphenyl ketone, 2-methyl-2-(4-morpholinyl)-1-[4-(methylthio)phenyl]-1-propanone, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide; and / or

[0072] The free radical scavenger is one or more of 2,6-di-tert-butyl-p-methylphenol, bis(1,2,2,6,6-pentamethylpiperidinol) sebacate, dimethylbenzene dibutylbenzofuranone, and 2,2,6,6-tetramethylpiperidinyl nitrogen oxide.

[0073] Compared with the "sol-gel method" of the prior art for preparing SiZrOC thermal insulation ceramic materials, the above method of the present application can induce a thiol click reaction under the action of ultraviolet light, so that the carbon-carbon double bonds in the photosensitive solution react with the thiol groups, cross-link to form a highly polymerized network structure, and then ceramicize the precursor through heat treatment at a certain temperature, and remove C and groups that cannot be maintained at high temperatures, thereby obtaining SiZrOC thermal insulation ceramic materials. Therefore, there is no need for long and complicated aging and low-temperature heat treatment, which greatly shortens the preparation cycle and improves the preparation efficiency of SiZrOC thermal insulation ceramic materials; wherein, the thiol click reaction includes the reaction of the carbon-carbon double bonds in the zirconium source solution with the thiol groups in the silicon source solution, and also includes the reaction of the carbon-carbon double bonds in the carbon-carbon double bond silicon source solution with the thiol groups in the thiol silicon source solution (that is, the carbon-carbon double bonds in the Si-containing organic matter containing multiple vinyl groups react with the thiol groups in the Si-containing organic matter containing multiple thiol groups). Among them, the average molecular weight of the carbon-carbon double bond silicon source solution is higher than that of the zirconium source solution. It undergoes a thiol click reaction with the thiol groups in the thiol silicon source solution. The network structure after cross-linking is tighter, which makes the molding accuracy higher in the additive manufacturing process. At the same time, the ceramic morphology obtained after heat treatment is better and the shrinkage is smaller, so that more complex thermal insulation devices can be obtained.

[0074] The reaction principle in this application can be found in Figure 1 The first equation (the one above) is that zirconium n-propoxide is mixed with acrylic acid to form zirconium acrylate, in which the acryloxy groups in zirconium acrylate can also react with each other to form a network structure; the second equation is the reaction in subsequent photocuring additive manufacturing. Under the induction of ultraviolet light, the thiol group reacts with the carbon-carbon double bond to form a cross-linked network structure.

[0075] On the other hand, the present invention provides a SiZrOC thermal insulation ceramic material, wherein the structure of the SiZrOC thermal insulation ceramic material is a simulated lattice structure; the SiZrOC thermal insulation ceramic material comprises an amorphous structure and ZrO2 crystals;

[0076] Preferably, ZrO2 crystals are dispersed in the amorphous structure; the grain size of the ZrO2 crystals is less than 3nm.

[0077] The pseudo-crystalline structure is an ideal octahedral lattice sandwich structure, that is, it has upper and lower panels (the thickness of the panels is 0.5-1.5 mm), and the porosity of the sandwich structure is 50%-70%.

[0078] The heat-resistant temperature of SiZrOC thermal insulation ceramic material is: 200-1600°C under inert gas conditions and 200-1400°C under air conditions; the thermal insulation efficiency of SiZrOC thermal insulation ceramic material is 65%-75% at 800°C; the compressive strength of SiZrOC thermal insulation ceramic material is 3-8MPa; preferably, SiZrOC thermal insulation ceramic material is obtained by any of the above preparation methods.

[0079] The present invention is further described below in conjunction with embodiments and comparative examples.

[0080] Example 1

[0081] This embodiment provides a method for preparing a SiZrOC thermal insulation ceramic material, comprising the following steps:

[0082] Step 1) Weigh 23.5g zirconium n-propoxide and 17.5g acrylic acid and stir them evenly, then treat them in an ice-water bath to obtain a zirconium source solution; mix 10g (mercapto) methylsiloxane-dimethylsiloxane copolymer (a Si-containing organic substance containing multiple mercapto groups, with an average molecular weight of 5500), 0.19g phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide (photoinitiator), and 0.19g 2,6-di-tert-butyl-p-methylphenol (radical scavenger) evenly, then add 1.4g methyl-vinyl (siloxane and polysiloxane) (a Si-containing organic substance containing multiple vinyl groups, with an average molecular weight of 500), stir evenly at room temperature to obtain a silicon source solution; mix 7.4g of the above zirconium source solution with the above silicon source solution, stir evenly at room temperature to obtain a photosensitive solution; mix the zirconium source solution with the silicon source solution to obtain a photosensitive solution;

[0083] The molar ratio of zirconium n-propoxide to acrylic acid is about 1:4; the temperature of the ice-water bath treatment is 0°C; the time of the ice-water bath treatment is 4 hours; the magnetic stirring is performed at a speed of 300 rpm during the ice-water bath treatment; in the photosensitive solution, the molar ratio of zirconium element in the zirconium source solution to silicon element in the silicon source solution is 0.25:1; in the photosensitive solution, the molar ratio of thiol to vinyl in the zirconium source solution and the silicon source solution is 1:1.46; in the photosensitive solution, the mass fraction of the photoinitiator is 1%, and the mass fraction of the free radical scavenger is 1%;

[0084] Step 2) using ultraviolet DLP additive manufacturing technology to perform additive manufacturing on the photosensitive solution (i.e., exposing the photosensitive solution layer by layer to form the photosensitive solution), so that the carbon-carbon double bonds in the zirconium source solution react with the thiol groups in the silicon source solution to obtain a precursor blank;

[0085] The wavelength of the ultraviolet light is 405nm; the parameters of DLP additive manufacturing are set as follows: the layer thickness is 80μm, and the exposure intensity is set to 12W / cm 2 , the exposure time is set to 4s;

[0086] Step 3) placing the precursor body into an atmosphere furnace, raising the temperature to 1000° C. at a rate of 1° C. / min under a flowing argon atmosphere, then keeping the temperature for 1 hour, and then cooling the temperature to room temperature at a rate of 5° C. / min; obtaining a SiZrOC thermal insulation ceramic material.

[0087] The precursor green body and SiZrOC thermal insulation ceramic material (whose surface morphology is a uniform black surface) prepared in this embodiment are shown in Figure 2 As shown in the figure, the overall size of the SiZrOC thermal insulation ceramic material is reduced by about 37% compared with the precursor body, while maintaining the same external and internal morphology and no obvious macroscopic defects. The thermal insulation infrared camera observation results of the SiZrOC thermal insulation ceramic material prepared in this embodiment are as follows: Figure 3 As shown in the figure, the zirconium-doped silicon oxygen carbon (SiZrOC) thermal insulation ceramic material is fixed with alumina thermal insulation bricks and placed in a muffle furnace with an internal temperature of 800°C. After constant temperature heating for 20 minutes, the temperature on the back of the thermal insulation tile is 205°C, that is, the thermal insulation efficiency is 74.4%. The XRD results of the material after heat treatment of SiZrOC thermal insulation ceramic material at 1200 to 1400°C in an aerobic environment for 6 hours are shown in the figure. Figure 4 It can be seen that the sample prepared in this embodiment remains amorphous under the treatment condition of 1200℃ for 6h in an aerobic environment, and only a small amount of silicon dioxide peak appears under the treatment condition of 1400℃ for 6h in an aerobic environment, and the matrix still remains amorphous, indicating that the material has good high-temperature stability.

[0088] Example 2

[0089] This embodiment provides a method for preparing a SiZrOC thermal insulation ceramic material, comprising the following steps:

[0090] Step 1) Weigh 23.5g zirconium n-propoxide and 17.5g acrylic acid and stir them evenly, then treat them in an ice-water bath to obtain a zirconium source solution; mix 10g (mercapto) methylsiloxane-dimethylsiloxane copolymer (a Si-containing organic substance containing multiple mercapto groups, with an average molecular weight of 5500), 0.19g phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide (photoinitiator), and 0.19g 2,6-di-tert-butyl-p-methylphenol (radical scavenger) evenly, then add 5.2g methyl-vinyl (siloxane and polysiloxane) (a Si-containing organic substance containing multiple vinyl groups, with an average molecular weight of 500), stir evenly at room temperature to obtain a silicon source solution; mix 4.4g of the above zirconium source solution with the above silicon source solution, stir evenly at room temperature to obtain a photosensitive solution; mix the zirconium source solution with the silicon source solution to obtain a photosensitive solution;

[0091] The molar ratio of zirconium n-propoxide to acrylic acid is about 1:4; the temperature of the ice-water bath treatment is 2°C; the time of the ice-water bath treatment is 5 hours; the magnetic stirring is performed at a speed of 500 rpm during the ice-water bath treatment; in the photosensitive solution, the molar ratio of zirconium element in the zirconium source solution to silicon element in the silicon source solution is 0.1:1; in the photosensitive solution, the molar ratio of thiol to vinyl in the zirconium source solution and the silicon source solution is 1:1.50; in the photosensitive solution, the mass fraction of the photoinitiator is 1%, and the mass fraction of the free radical scavenger is 1%;

[0092] Step 2) using ultraviolet DLP additive manufacturing technology to perform additive manufacturing on the photosensitive solution (i.e., exposing the photosensitive solution layer by layer to form the photosensitive solution), so that the carbon-carbon double bonds in the zirconium source solution react with the thiol groups in the silicon source solution to obtain a precursor blank;

[0093] The wavelength of the ultraviolet light is 405nm; the parameters of DLP additive manufacturing are set as follows: the layer thickness is 80μm, and the exposure intensity is set to 12W / cm 2 , the exposure time is set to 5s;

[0094] Step 3) placing the precursor body into an atmosphere furnace, raising the temperature to 1000° C. at a rate of 1° C. / min under a flowing argon atmosphere, then keeping the temperature for 1 hour, and then cooling the temperature to room temperature at a rate of 5° C. / min; obtaining a SiZrOC thermal insulation ceramic material.

[0095] The microstructure of the SiZrOC thermal insulation ceramic material prepared in this embodiment is as follows: Figure 5 As shown in the figure, it can be seen that there are no obvious defects in its microstructure, and the 3D printing layer is obvious. The thickness of the precursor green body is about 81μm, and the thickness of the ceramic middle layer is about 64μm. The material composition of the zirconium-doped silicon oxygen carbon (SiZrOC) insulating ceramic material after heat treatment at 1200 to 1400℃ in an oxygen environment for 6 hours is shown in Figure 3It can be seen that the sample prepared in this embodiment has a small amount of crystal peaks under the treatment condition of 1200℃ for 6h in an aerobic environment, but the matrix remains amorphous. Under the treatment condition of 1400℃ for 6h in an aerobic environment, a relatively obvious crystal peak (silicon dioxide, silicon carbide, zirconium dioxide) appears, indicating that the material has partially crystallized under this environmental condition, but a large amount of amorphous matrix still exists. Compared with Example 1, this embodiment has a higher degree of crystallization under the same heat treatment conditions, mainly because the zirconium content in this embodiment is reduced, and the ability to inhibit amorphous crystallization is weakened.

[0096] Example 3

[0097] This embodiment provides a method for preparing a SiZrOC thermal insulation ceramic material, comprising the following steps:

[0098] Step 1) Weigh 23.5g zirconium n-propoxide and 17.5g acrylic acid and stir them evenly, then treat them in an ice-water bath to obtain a zirconium source solution; mix 10g (mercapto) methylsiloxane-dimethylsiloxane copolymer (a Si-containing organic substance containing multiple mercapto groups, with an average molecular weight of 5500), 0.30g phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide (photoinitiator), and 0.19g 2,6-di-tert-butyl-p-methylphenol (radical scavenger) evenly, then add 8.3g methyl-vinyl (siloxane and polysiloxane) (a Si-containing organic substance containing multiple vinyl groups, with an average molecular weight of 500), stir evenly at room temperature to obtain a silicon source solution; mix 1.5g of the above zirconium source solution with the above silicon source solution, stir evenly at room temperature to obtain a photosensitive solution; mix the zirconium source solution with the silicon source solution to obtain a photosensitive solution;

[0099] The molar ratio of zirconium n-propoxide to acrylic acid is about 1:4; the temperature of the ice-water bath treatment is 0°C; the time of the ice-water bath treatment is 4 hours; the magnetic stirring is performed at a speed of 300 rpm during the ice-water bath treatment; in the photosensitive solution, the molar ratio of zirconium element in the zirconium source solution to silicon element in the silicon source solution is 0.03:1; in the photosensitive solution, the molar ratio of thiol to vinyl in the zirconium source solution and the silicon source solution is 1:1.45; in the photosensitive solution, the mass fraction of the photoinitiator is 1.5%, and the mass fraction of the free radical scavenger is 1%;

[0100] Step 2) using ultraviolet DLP additive manufacturing technology to perform additive manufacturing on the photosensitive solution (i.e., exposing the photosensitive solution layer by layer to form the photosensitive solution), so that the carbon-carbon double bonds in the zirconium source solution react with the thiol groups in the silicon source solution to obtain a precursor blank;

[0101] The wavelength of the ultraviolet light is 365nm; the parameters of DLP additive manufacturing are set as follows: the layer thickness is 80μm, and the exposure intensity is set to 15W / cm 2 , the exposure time is set to 4s;

[0102] Step 3) placing the precursor body into an atmosphere furnace, raising the temperature to 1000° C. at a rate of 1° C. / min under a flowing argon atmosphere, then keeping the temperature for 1 hour, and then cooling the temperature to room temperature at a rate of 5° C. / min; obtaining a SiZrOC thermal insulation ceramic material.

[0103] The thermal insulation effect of the SiZrOC thermal insulation ceramic material prepared in this embodiment is observed by an infrared camera. Figure 6 As shown in the figure, the zirconium-doped silicon oxygen carbon (SiZrOC) thermal insulation ceramic material was fixed with alumina thermal insulation bricks and placed in a muffle furnace at 800°C. After constant temperature heating for 20 minutes, the temperature on the back of the thermal insulation tile was 263°C, that is, the thermal insulation efficiency was 67.1%.

[0104] Example 4

[0105] This embodiment provides a method for preparing a SiZrOC thermal insulation ceramic material, comprising the following steps:

[0106] Step 1) Weigh 23.5g zirconium n-propoxide and 3.62g acrylic acid and stir them evenly, then treat them in an ice-water bath to obtain a zirconium source solution; mix 10g (mercapto) methylsiloxane-dimethylsiloxane copolymer (a Si-containing organic substance containing multiple mercapto groups with an average molecular weight of 5500), 0.25g phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide (photoinitiator), and 0.25g 2,6-di-tert-butyl-p-methylphenol (radical scavenger) evenly, then add 7.3g methyl-vinyl (siloxane and polysiloxane) (a Si-containing organic substance containing multiple vinyl groups with an average molecular weight of 500), stir evenly at room temperature to obtain a silicon source solution; mix 1.5g of the above zirconium source solution with the above silicon source solution, stir evenly at room temperature to obtain a photosensitive solution; mix the zirconium source solution with the silicon source solution to obtain a photosensitive solution;

[0107] The molar ratio of zirconium n-propoxide to acrylic acid is about 1:1; the temperature of the ice-water bath treatment is 6°C; the time of the ice-water bath treatment is 6 hours; the magnetic stirring is performed at a speed of 600 rpm during the ice-water bath treatment; in the photosensitive solution, the molar ratio of zirconium element in the zirconium source solution to silicon element in the silicon source solution is 0.03:1; in the photosensitive solution, the molar ratio of thiol to vinyl in the zirconium source solution and the silicon source solution is 1:1.13; in the photosensitive solution, the mass fraction of the photoinitiator is 1.3%, and the mass fraction of the free radical scavenger is 1.3%;

[0108] Step 2) using ultraviolet DLP additive manufacturing technology to perform additive manufacturing on the photosensitive solution (i.e., exposing the photosensitive solution layer by layer to form the photosensitive solution), so that the carbon-carbon double bonds in the zirconium source solution react with the thiol groups in the silicon source solution to obtain a precursor blank;

[0109] The wavelength of the ultraviolet light is 380nm; the parameters of DLP additive manufacturing are set as follows: the layer thickness is 80μm, and the exposure intensity is set to 12W / cm 2 , the exposure time is set to 4s;

[0110] Step 3) placing the precursor body into an atmosphere furnace, raising the temperature to 1000° C. at a rate of 1° C. / min under a flowing argon atmosphere, then keeping the temperature for 1 hour, and then cooling the temperature to room temperature at a rate of 5° C. / min; obtaining a SiZrOC thermal insulation ceramic material.

[0111] The microstructure of the SiZrOC thermal insulation ceramic material prepared in this example is as follows: Figure 7 As shown in the figure, it can be seen that there are no obvious defects in its microstructure and the 3D printing stratification is obvious.

[0112] Example 5

[0113] This embodiment provides a method for preparing a SiZrOC thermal insulation ceramic material, comprising the following steps:

[0114] Step 1) Weigh 23.5g zirconium n-propoxide and 17.5g acrylic acid and stir them evenly, then treat them in an ice-water bath to obtain a zirconium source solution; mix 10g (mercapto) methylsiloxane-dimethylsiloxane copolymer (a Si-containing organic substance containing multiple mercapto groups, with an average molecular weight of 5500), 0.37g phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide (photoinitiator), and 0.28g 2,6-di-tert-butyl-p-methylphenol (radical scavenger) evenly, then add 1.4g methyl-vinyl (siloxane and polysiloxane) (a Si-containing organic substance containing multiple vinyl groups, with an average molecular weight of 500), stir evenly at room temperature to obtain a silicon source solution; mix 7.4g of the above zirconium source solution with the above silicon source solution, stir evenly at room temperature to obtain a photosensitive solution; mix the zirconium source solution with the silicon source solution to obtain a photosensitive solution;

[0115] The molar ratio of zirconium n-propoxide to acrylic acid is about 1:4; the temperature of the ice-water bath treatment is 0°C; the time of the ice-water bath treatment is 4 hours; the magnetic stirring is performed at a speed of 300 rpm during the ice-water bath treatment; in the photosensitive solution, the molar ratio of zirconium element in the zirconium source solution to silicon element in the silicon source solution is 0.25:1; in the photosensitive solution, the molar ratio of thiol to vinyl in the zirconium source solution and the silicon source solution is 1:1.46; in the photosensitive solution, the mass fraction of the photoinitiator is 2%, and the mass fraction of the free radical scavenger is 1.5%;

[0116] Step 2) using ultraviolet DLP additive manufacturing technology to perform additive manufacturing on the photosensitive solution (i.e., exposing the photosensitive solution layer by layer to form the photosensitive solution), so that the carbon-carbon double bonds in the zirconium source solution react with the thiol groups in the silicon source solution to obtain a precursor blank;

[0117] The wavelength of the ultraviolet light is 405nm; the parameters of DLP additive manufacturing are set as follows: the layer thickness is 80μm, and the exposure intensity is set to 18W / cm 2 , the exposure time is set to 4s;

[0118] Step 3) placing the precursor body into an atmosphere furnace, raising the temperature to 1000° C. at a rate of 5° C. / min under a flowing argon atmosphere, then keeping the temperature for 1 hour, and then cooling the temperature to room temperature at a rate of 5° C. / min; obtaining a SiZrOC thermal insulation ceramic material.

[0119] The SiZrOC thermal insulation ceramic material prepared in this embodiment has a microscopic morphology after being subjected to an oxygen-free heat treatment at 1600°C for 6 hours. Figure 8 As shown in the figure, it can be seen that the SiZrOC thermal insulation ceramic material has a small number of precipitated grains, the size of which is at the nanometer level and has high thermal stability.

[0120] It is easy for those skilled in the art to understand that, without conflict, the advantageous technical features of the above-mentioned methods can be freely combined and superimposed.

[0121] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention. The above description is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and variations can be made without departing from the technical principles of the present invention. These improvements and variations should also be regarded as the protection scope of the present invention.

Claims

1. A method for preparing a SiZrOC thermal insulation ceramic material, characterized in that: The following steps are involved: Step 1) mixing a zirconium source solution and a silicon source solution to obtain a photosensitive solution; wherein the zirconium source solution contains a carbon-carbon double bond, and the silicon source solution contains a thiol group and a carbon-carbon double bond; Step 2) subjecting the photosensitive solution to ultraviolet radiation so that the carbon-carbon double bonds in the photosensitive solution react with the thiol groups, and simultaneously subjecting the photosensitive solution to a molding process to obtain a precursor body; Step 3) heat-treating the precursor body to obtain SiZrOC thermal insulation ceramic material.

2. The method for preparing the SiZrOC thermal insulation ceramic material according to claim 1, characterized in that: In the step 1), the method further comprises the step of preparing the zirconium source solution: mixing zirconium n-propoxide with acrylic acid, and then treating the mixture in an ice-water bath to obtain a zirconium source solution; Preferably, the molar ratio of zirconium n-propoxide to acrylic acid is 1:1-4; Preferably, the temperature of the ice water bath treatment is 0-6°C; Preferably, the ice water bath treatment time is 4-6 hours.

3. The method for preparing the SiZrOC thermal insulation ceramic material according to claim 1, characterized in that: In the step 1), the method further comprises the step of preparing the silicon source solution: mixing a Si-containing organic substance containing multiple thiol groups, a Si-containing organic substance containing multiple vinyl groups, a photoinitiator, and a free radical scavenger to obtain a silicon source solution; Preferably, the molar ratio of thiol to vinyl in the photosensitive solution is 1:0.5-3; Preferably, the Si-containing organic compound containing multiple thiol groups is a Si-containing oligomer containing multiple thiol groups or a Si-containing monomer containing multiple thiol groups; Preferably, the Si-containing organic compound containing multiple vinyl groups is a Si-containing oligomer containing multiple vinyl groups or a Si-containing monomer containing multiple vinyl groups; Preferably, the average molecular weight of the Si-containing organic compound containing multiple thiol groups is 200-8000; Preferably, the Si-containing organic compound containing multiple mercapto groups is one or more of (mercapto)methylsiloxane-dimethylsiloxane copolymer, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, and (mercaptopropyl)methylsiloxane copolymer; Preferably, the average molecular weight of the Si-containing organic compound containing multiple vinyl groups is 200-8000; Preferably, the Si-containing organic compound containing multiple vinyl groups is one or more of a block copolymer of dimethylsiloxane and diphenylsiloxane, vinyl polydimethylsiloxane, vinyl-terminated polyphenylsiloxane, vinyl methoxysiloxane copolymer, and methyl-vinyl (siloxane and polysiloxane).

4. The method for preparing the SiZrOC thermal insulation ceramic material according to claim 1, characterized in that: In the step 1): In the photosensitive solution, the molar ratio of zirconium element in the zirconium source solution to silicon element in the silicon source solution is 0.01-0.35:

1.

5. The method for preparing the SiZrOC thermal insulation ceramic material according to claim 3, characterized in that: In the step of preparing the silicon source solution: The photoinitiator is one or more of 2-hydroxy-2-methyl-1-phenylpropanone, 1-hydroxycyclohexylphenyl ketone, 2-methyl-2-(4-morpholinyl)-1-[4-(methylthio)phenyl]-1-propanone, and phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide; and / or The free radical scavenger is one or more of 2,6-di-tert-butyl-p-methylphenol, bis(1,2,2,6,6-pentamethylpiperidinol) sebacate, dimethylbenzene dibutylbenzofuranone, and 2,2,6,6-tetramethylpiperidinyl nitrogen oxide.

6. The method for preparing the SiZrOC thermal insulation ceramic material according to claim 5, characterized in that: In the photosensitive solution, the mass fraction of the photoinitiator is 0.05-2%, and the mass fraction of the free radical scavenger is 0.05-2%.

7. The method for preparing SiZrOC thermal insulation ceramic material according to claim 1, characterized in that: In the step 2): The wavelength of ultraviolet light during ultraviolet irradiation is 365-405nm; and / or The photosensitive solution is molded by using DLP additive manufacturing technology; The parameters of DLP additive manufacturing are set as follows: layer thickness is 40-200μm, and exposure intensity is set to 1-100mW / cm 2 , the exposure time is set to 0.5-30s.

8. The method for preparing SiZrOC thermal insulation ceramic material according to claim 1, characterized in that: In the step 3), the step of heat treating the precursor body comprises: In an inert atmosphere, the precursor body is heated to 800-1000° C., kept at this temperature for 0.5-10 hours, and then cooled to room temperature; Preferably, the inert atmosphere is argon; Preferably, the rate of heating the precursor body is 0.5-10°C / min; Preferably, the precursor body is cooled at a rate of 1-5°C / min.

9. A SiZrOC thermal insulation ceramic material, characterized in that: The structure of the SiZrOC thermal insulation ceramic material is a simulated lattice structure; the SiZrOC thermal insulation ceramic material includes amorphous structure and ZrO2 crystals; Preferably, the ZrO2 crystals are dispersed in the amorphous structure; the grain size of the ZrO2 crystals is less than 3 nm.

10. The SiZrOC thermal insulation ceramic material according to claim 9, characterized in that: The heat-resistant temperature of the SiZrOC thermal insulation ceramic material is: 200-1600°C under inert gas conditions and 200-1400°C under air conditions; the thermal insulation efficiency of the SiZrOC thermal insulation ceramic material is 65%-75% at 800°C; the compressive strength of the SiZrOC thermal insulation ceramic material is 3-8MPa; Preferably, the SiZrOC thermal insulation ceramic material is obtained by the preparation method according to any one of claims 1 to 8.

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