High-speed thin film ceramic based on pore structure and preparation method of high-speed thin film ceramic

Abstract

The invention discloses high-speed thin film ceramic based on a pore structure and a preparation method of the high-speed thin film ceramic based on the pore structure, and the high-speed thin film ceramic based on the pore structure comprises the following components in percentage by mass: 30-50% of aluminum oxide; 10 to 20% of zirconium oxide; 5-15% of yttrium oxide; 5-10% of silicon carbide; 2-8% of cerous nitrate; 2-8% of lanthanum nitrate; 5-10% of magnesium lithium silicate; 10 to 20% of polymethyl methacrylate; 5 to 15% of nano silicon dioxide; through innovative component design, zirconium oxide and yttrium oxide are introduced, so that the toughness of the ceramic can be remarkably improved, and meanwhile, the thermal shock resistance is improved; the cerous nitrate and lanthanum nitrate components can effectively inhibit grain growth and improve the density of the ceramic and the uniformity of a microstructure, so that the overall performance of the ceramic is improved; the polymethyl methacrylate and the magnesium lithium silicate can be decomposed and volatilized in the sintering process, a large number of pores are left, the uniformity and the size of the pores can be adjusted through the nanometer silicon dioxide, and therefore the high porosity is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of ceramic materials, and in particular relates to a high-rate thin-film ceramic based on a pore structure and a preparation method thereof. Background Art

[0002] With the continuous development of science and technology, the demand for high-performance ceramic materials is increasing. Traditional ceramic materials often have problems such as insufficient toughness and poor thermal shock resistance in high-rate applications. Thin-film ceramics, due to their unique structure and properties, have broad application prospects in electronics, aerospace and other fields. However, the current thin-film ceramic preparation methods have problems such as complex processes, high costs, and unstable performance, which limit their large-scale application. Therefore, it is of great significance to develop a high-rate thin-film ceramic based on a porous structure and an efficient and low-cost preparation method. Summary of the Invention

[0003] In view of the above situation, in order to overcome the defects of the prior art, the present invention provides a high-rate thin film ceramic based on a porous structure and a preparation method thereof, which effectively solves the problems raised in the above background.

[0004] To achieve the above-mentioned object, the present invention provides the following technical solution: a high-rate thin-film ceramic based on a porous structure, comprising the following components in percentage by mass:

[0005] Alumina: 30-50%;

[0006] Zirconia: 10-20%;

[0007] Yttrium oxide: 5-15%;

[0008] Silicon carbide: 5-10%;

[0009] Cerium nitrate: 2-8%;

[0010] Lanthanum nitrate: 2-8%;

[0011] Lithium magnesium silicate: 5-10%;

[0012] Polymethyl methacrylate: 10-20%;

[0013] Nano-silicon dioxide: 5-15%.

[0014] A method for preparing a high-rate thin-film ceramic based on a porous structure comprises the following steps:

[0015] S1: Raw material mixing: according to the above-mentioned component ratio, aluminum oxide, zirconium oxide, yttrium oxide, silicon carbide, cerium nitrate, lanthanum nitrate, lithium magnesium silicate, polymethyl methacrylate and nano-silica are weighed respectively, and added into a ball mill for mixing, and an appropriate amount of deionized water is added as a dispersion medium; during the ball milling process, the raw material particles are fully mixed under the action of mechanical force, and partially ground at the same time, so that the particle size is reduced and the distribution is more uniform, providing a good foundation for the subsequent preparation process;

[0016] S2: Drying and grinding: The milled slurry is taken out and placed in a drying oven at 60-80°C for 10-20 hours to remove moisture and obtain a dry powder; then, the dried powder is placed in a grinder and ground for 30-60 minutes to further refine the particles and ensure the uniformity of the powder;

[0017] S3: Mold forming: Pour the ground powder into a mold and use a tablet press to press the powder. The pressure of the tablet press is 10-30 MPa and the holding time is 5-15 minutes. During the pressing process, the powder is tightly packed under the pressure to form a green body with a certain strength and shape.

[0018] S4: Sintering treatment: The pressed green body is placed in a sintering furnace and heated to 1000-1200°C at a heating rate of 5-10°C / min, kept at this temperature for 2-4 hours, and then cooled to room temperature with the furnace. During the sintering process, polymethyl methacrylate and lithium magnesium silicate decompose and volatilize to form a large number of pores, while nano-silica adjusts the uniformity and size of the pores, thereby achieving high porosity.

[0019] S5: Post-processing: After the sintered ceramic film is taken out, the surface is polished as needed; the surface of the film is polished with a diamond grinding wheel to remove burrs and uneven parts on the surface, so that the surface roughness reaches Ra0.1-0.5 microns, making the surface of the film smooth.

[0020] Preferably, in the step S1: mixing raw materials, after the materials are placed in a ball mill, the speed of the ball mill is controlled to be 150-250 r / min, and the ball milling time is 10-15 hours.

[0021] Preferably, in the step S2: drying and grinding, the particle size of the ground powder is 1-5 microns, thereby ensuring that the subsequently prepared film has good density and uniformity.

[0022] Preferably, in the step S3: mold forming, the shape and size of the mold are designed according to the final shape of the desired thin film ceramic to meet the needs of different application scenarios.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. The present invention utilizes innovative component design. The introduction of zirconium oxide and yttrium oxide significantly enhances the toughness of the ceramic while also improving its thermal shock resistance. Cerium nitrate and lanthanum nitrate effectively inhibit grain growth, increasing the density and microstructural uniformity of the ceramic, thereby enhancing its overall performance. Polymethyl methacrylate and lithium magnesium silicate are introduced to form a highly porous structure during the sintering process. Polymethyl methacrylate and lithium magnesium silicate decompose and volatilize during the sintering process, leaving behind a large number of pores, while nano-silica can adjust the uniformity and size of the pores, thereby achieving a high porosity. These components effectively improve the microstructure and performance of the ceramic, giving it higher toughness and thermal shock resistance in high-rate applications.

[0025] 2. The preparation method is simple and low-cost, and conventional ball milling, drying, molding and sintering processes are used, making it easy to achieve large-scale production;

[0026] 3. The prepared thin film ceramics have good density and uniformity, reasonable pore structure, and can meet the material performance requirements of different application scenarios. DETAILED DESCRIPTION

[0027] The technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all 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.

[0028] The present invention provides a high-rate thin-film ceramic based on a porous structure, comprising the following components in percentage by mass:

[0029] Alumina: 30-50%;

[0030] Zirconia: 10-20%;

[0031] Yttrium oxide: 5-15%;

[0032] Silicon carbide: 5-10%;

[0033] Cerium nitrate: 2-8%;

[0034] Lanthanum nitrate: 2-8%;

[0035] Lithium magnesium silicate: 5-10%;

[0036] Polymethyl methacrylate: 10-20%;

[0037] Nano-silicon dioxide: 5-15%;

[0038] Among them, alumina as the main matrix component provides good mechanical strength and chemical stability;

[0039] The addition of zirconium oxide and yttrium oxide can significantly improve the toughness of ceramics and improve thermal shock resistance;

[0040] The introduction of silicon carbide can enhance the thermal conductivity of ceramics, which helps to dissipate heat quickly in high-speed applications;

[0041] Cerium nitrate and lanthanum nitrate are innovative ingredients that can effectively inhibit grain growth, increase the density and microstructural uniformity of ceramics, and thus enhance their overall performance;

[0042] Polymethyl methacrylate and lithium magnesium silicate are used to form a highly porous structure during the sintering process. Polymethyl methacrylate and lithium magnesium silicate will decompose and volatilize during the sintering process, leaving a large number of pores, while nano-silica can adjust the uniformity and size of the pores to achieve high porosity.

[0043] A method for preparing a high-rate thin-film ceramic based on a porous structure comprises the following steps:

[0044] S1: Raw material mixing: according to the above-mentioned component ratio, aluminum oxide, zirconium oxide, yttrium oxide, silicon carbide, cerium nitrate, lanthanum nitrate, lithium magnesium silicate, polymethyl methacrylate and nano-silica are weighed respectively, and added into a ball mill for mixing, and an appropriate amount of deionized water is added as a dispersion medium; during the ball milling process, the raw material particles are fully mixed under the action of mechanical force, and partially ground at the same time, so that the particle size is reduced and the distribution is more uniform, providing a good foundation for the subsequent preparation process;

[0045] S2: Drying and grinding: The milled slurry is taken out and placed in a drying oven at 60-80°C for 10-20 hours to remove moisture and obtain a dry powder; then, the dried powder is placed in a grinder and ground for 30-60 minutes to further refine the particles and ensure the uniformity of the powder;

[0046] S3: Mold forming: Pour the ground powder into a mold and use a tablet press to press the powder. The pressure of the tablet press is 10-30 MPa and the holding time is 5-15 minutes. During the pressing process, the powder is tightly packed under the pressure to form a green body with a certain strength and shape.

[0047] S4: Sintering treatment: The pressed green body is placed in a sintering furnace and heated to 1000-1200°C at a heating rate of 5-10°C / min, kept at this temperature for 2-4 hours, and then cooled to room temperature with the furnace. During the sintering process, polymethyl methacrylate and lithium magnesium silicate decompose and volatilize to form a large number of pores, while nano-silica adjusts the uniformity and size of the pores, thereby achieving high porosity.

[0048] S5: Post-processing: After the sintered ceramic film is taken out, the surface is polished as needed; the surface of the film is polished with a diamond grinding wheel to remove burrs and uneven parts on the surface, so that the surface roughness reaches Ra0.1-0.5 microns, making the surface of the film smooth.

[0049] In S1 of this embodiment, in the raw material mixing step, after each material is placed in a ball mill, the speed of the ball mill is controlled to be 150-250 r / min, and the ball milling time is 10-15 hours.

[0050] In the drying and grinding step S2 of this embodiment, the particle size of the powder after grinding is 1-5 microns, thereby ensuring that the subsequently prepared film has good density and uniformity.

[0051] In S3 of this embodiment, in the mold forming step, the shape and size of the mold are designed according to the final shape of the desired thin film ceramic to meet the needs of different application scenarios.

[0052] Detailed description of porosity measurement and control

[0053] 1. Porosity measurement method

[0054] To ensure the accuracy and repeatability of porosity, the present invention adopts the following two main methods to measure porosity:

[0055] 1.1 Archimedes drainage method

[0056] The Archimedean drainage method is a classic porosity measurement method suitable for porous materials. The specific steps are as follows:

[0057] 1) Weighing the sample: Weigh the sintered thin film ceramic sample and record its mass m (unit: g);

[0058] 2) Measure volume: Immerse the sample completely in water and measure its drainage volume V 排水 (Unit: cubic centimeters);

[0059] Calculate the porosity: According to the theoretical density ρ of the sample 理论 and the actual density ρ 实际 , calculate the porosity P:

[0060]

[0061] Among them, the actual density ρ 实际 Calculated by drainage volume:

[0062]

[0063] Theoretical density ρ 理论It is calculated based on the weighted average of the theoretical density of the material components.

[0064] 1.2 Scanning electron microscopy (SEM) combined with image analysis

[0065] Scanning electron microscopy (SEM) combined with image analysis is a high-precision porosity measurement method suitable for microstructural analysis. The specific steps are as follows:

[0066] 1) Sample preparation: Slice the sintered thin film ceramic sample into thin slices and perform surface polishing;

[0067] 2) Image capture: Use a scanning electron microscope (SEM) to capture cross-sectional images of the sample at a magnification of 1000-5000 times;

[0068] 3) Image analysis: Use image analysis software (such as ImageJ or MATLAB) to process the SEM images and calculate the porosity. The software determines the porosity P by identifying the pore area and calculating its area ratio:

[0069]

[0070] 2. Porosity control method

[0071] This is achieved by:

[0072] 2.1 Adjust the amount of organic matter added

[0073] Polymethyl methacrylate and lithium magnesium silicate will decompose and volatilize during the sintering process, forming pores. By adjusting their addition amount, the porosity can be controlled:

[0074] Polymethyl methacrylate addition amount: Increasing the amount of PMMA can increase the porosity. The addition amount range is 10-20% (mass percentage);

[0075] The amount of lithium magnesium silicate added: The amount of lithium magnesium silicate added will also affect the porosity. The recommended addition range is 5-10% (mass percentage);

[0076] 2.2 Control sintering temperature and holding time

[0077] Sintering temperature and holding time have a significant impact on porosity:

[0078] Sintering temperature: A higher sintering temperature helps to completely decompose and volatilize organic matter, but too high a temperature may cause pore collapse. The sintering temperature range is 1000-1200℃;

[0079] Holding time: A longer holding time can ensure that organic matter is fully decomposed, but too long a holding time may lead to unstable pore structure. The holding time range is 2-4 hours;

[0080] 2.3 Adding nano-silica

[0081] Nano-silica can adjust the uniformity and size of pores, thereby optimizing porosity:

[0082] Nano-silica addition amount: The addition amount ranges from 5-15% (mass percentage). Nano-silica can form a stable pore structure during the sintering process to prevent pore collapse;

[0083] 3. Experimental Verification

[0084] In order to verify the effectiveness of the above method, the following experiments were conducted:

[0085] Experiment 1: The addition amounts of polymethyl methacrylate and lithium magnesium silicate were fixed at 15% and 7.5%, respectively. The sintering temperatures were adjusted to 1000°C, 1100°C, and 1200°C, with a holding time of 3 hours. The porosity at different temperatures was measured, and the results are shown in the following table:

[0086] Sintering temperature (℃) Porosity (%) 1000 58 1100 62 1200 65

[0087] Experiment 2: The sintering temperature was fixed at 1100°C and the holding time was 3 hours. The addition amounts of polymethyl methacrylate and lithium magnesium silicate were adjusted to 10%, 15%, and 20%, respectively. The porosity at different addition amounts was measured, and the results are shown in the following table:

[0088]

[0089] The above experiments have verified that the porosity control method of the present invention can effectively achieve a porosity range of 55-70% while ensuring the uniformity and stability of the pore structure.

[0090] Example 1:

[0091] A high-rate thin-film ceramic based on a porous structure, comprising the following components in percentage by mass:

[0092] Alumina: 30%;

[0093] Zirconia: 10%;

[0094] Yttrium oxide: 5%;

[0095] Silicon carbide: 5%;

[0096] Cerium nitrate: 2%;

[0097] Lanthanum nitrate: 2%;

[0098] Lithium magnesium silicate: 5%;

[0099] Polymethyl methacrylate: 10%;

[0100] Nano-silicon dioxide: 5%.

[0101] A method for preparing a high-rate thin-film ceramic based on a porous structure comprises the following steps:

[0102] S1: Raw material mixing: according to the above-mentioned component ratio, aluminum oxide, zirconium oxide, yttrium oxide, silicon carbide, cerium nitrate, lanthanum nitrate, lithium magnesium silicate, polymethyl methacrylate and nano-silica are weighed respectively, and added into a ball mill for mixing, and an appropriate amount of deionized water is added as a dispersion medium; during the ball milling process, the raw material particles are fully mixed under the action of mechanical force, and partially ground at the same time, so that the particle size is reduced and the distribution is more uniform, providing a good foundation for the subsequent preparation process;

[0103] S2: Drying and grinding: The milled slurry is taken out and placed in a drying oven at 60°C for 10 hours to remove moisture and obtain a dry powder. Subsequently, the dried powder is placed in a grinder and ground for 30 minutes to further refine the particles and ensure the uniformity of the powder.

[0104] S3: Mold forming: Pour the ground powder into a mold and use a tablet press to press the powder. The pressure of the tablet press is 10 MPa and the holding time is 5 minutes. During the pressing process, the powder is tightly packed under the action of pressure to form a green body with a certain strength and shape.

[0105] S4: Sintering treatment: The pressed green body is placed in a sintering furnace and heated to 1000°C at a heating rate of 5°C / min, kept at this temperature for 2 hours, and then cooled to room temperature with the furnace. During the sintering process, polymethyl methacrylate and lithium magnesium silicate decompose and volatilize to form a large number of pores, while nano-silica adjusts the uniformity and size of the pores, thereby achieving high porosity.

[0106] S5: Post-processing: After the sintered ceramic film is taken out, the surface is polished as needed; the surface of the film is polished with a diamond grinding wheel to remove burrs and uneven parts on the surface, so that the surface roughness reaches Ra0.1 microns, making the surface of the film smooth.

[0107] In S1 of this embodiment, in the raw material mixing step, after each material is placed in a ball mill, the speed of the ball mill is controlled to be 150 r / min, and the ball milling time is 10 hours.

[0108] In the drying and grinding step S2 of this embodiment, the particle size of the powder after grinding is 1 micron, thereby ensuring that the subsequently prepared film has good density and uniformity.

[0109] In S3 of this embodiment, in the mold forming step, the shape and size of the mold are designed according to the final shape of the desired thin film ceramic to meet the needs of different application scenarios.

[0110] Example 2:

[0111] A high-rate thin-film ceramic based on a porous structure, comprising the following components in percentage by mass:

[0112] Alumina: 50%;

[0113] Zirconia: 20%;

[0114] Yttrium oxide: 15%;

[0115] Silicon carbide: 10%;

[0116] Cerium nitrate: 8%;

[0117] Lanthanum nitrate: 8%;

[0118] Lithium magnesium silicate: 10%;

[0119] Polymethyl methacrylate: 20%;

[0120] Nano-silicon dioxide: 15%.

[0121] A method for preparing a high-rate thin-film ceramic based on a porous structure comprises the following steps:

[0122] S1: Raw material mixing: according to the above-mentioned component ratio, aluminum oxide, zirconium oxide, yttrium oxide, silicon carbide, cerium nitrate, lanthanum nitrate, lithium magnesium silicate, polymethyl methacrylate and nano-silica are weighed respectively, and added into a ball mill for mixing, and an appropriate amount of deionized water is added as a dispersion medium; during the ball milling process, the raw material particles are fully mixed under the action of mechanical force, and partially ground at the same time, so that the particle size is reduced and the distribution is more uniform, providing a good foundation for the subsequent preparation process;

[0123] S2: Drying and grinding: The milled slurry is taken out and placed in a drying oven at 80°C for 20 hours to remove moisture and obtain a dry powder. Subsequently, the dried powder is placed in a grinder and ground for 60 minutes to further refine the particles and ensure the uniformity of the powder.

[0124] S3: Mold forming: Pour the ground powder into a mold and use a tablet press to press the powder. The pressure of the tablet press is 10-30 MPa and the holding time is 5-15 minutes. During the pressing process, the powder is tightly packed under the pressure to form a green body with a certain strength and shape.

[0125] S4: Sintering treatment: The pressed green body is placed in a sintering furnace and heated to 1200°C at a heating rate of 10°C / min, kept at this temperature for 4 hours, and then cooled to room temperature in the furnace. During the sintering process, polymethyl methacrylate and lithium magnesium silicate decompose and volatilize to form a large number of pores, while nano-silica adjusts the uniformity and size of the pores, thereby achieving high porosity.

[0126] S5: Post-processing: After the sintered ceramic film is taken out, the surface is polished as needed; the surface of the film is polished with a diamond grinding wheel to remove burrs and uneven parts on the surface, so that the surface roughness reaches Ra0.5 microns, making the surface of the film smooth.

[0127] In S1 of this embodiment, in the raw material mixing step, after the materials are placed in the ball mill, the speed of the ball mill is controlled to 250 r / min, and the ball milling time is 15 hours.

[0128] In the drying and grinding step S2 of this embodiment, the particle size of the powder after grinding is 5 microns, thereby ensuring that the subsequently prepared film has good density and uniformity.

[0129] In S3 of this embodiment, in the mold forming step, the shape and size of the mold are designed according to the final shape of the desired thin film ceramic to meet the needs of different application scenarios.

[0130] Example 3:

[0131] A high-rate thin-film ceramic based on a porous structure, comprising the following components in percentage by mass:

[0132] Alumina: 40%;

[0133] Zirconia: 15%;

[0134] Yttrium oxide: 10%;

[0135] Silicon carbide: 7.5%;

[0136] Cerium nitrate: 5%;

[0137] Lanthanum nitrate: 5%;

[0138] Lithium magnesium silicate: 7.5%;

[0139] Polymethyl methacrylate: 15%;

[0140] Nano-silicon dioxide: 10%.

[0141] A method for preparing a high-rate thin-film ceramic based on a porous structure comprises the following steps:

[0142] S1: Raw material mixing: according to the above-mentioned component ratio, aluminum oxide, zirconium oxide, yttrium oxide, silicon carbide, cerium nitrate, lanthanum nitrate, lithium magnesium silicate, polymethyl methacrylate and nano-silica are weighed respectively, and added into a ball mill for mixing, and an appropriate amount of deionized water is added as a dispersion medium; during the ball milling process, the raw material particles are fully mixed under the action of mechanical force, and partially ground at the same time, so that the particle size is reduced and the distribution is more uniform, providing a good foundation for the subsequent preparation process;

[0143] S2: Drying and grinding: The milled slurry is taken out and placed in a drying oven at 70°C for 15 hours to remove moisture and obtain a dry powder. Subsequently, the dried powder is placed in a grinder and ground for 45 minutes to further refine the particles and ensure the uniformity of the powder.

[0144] S3: Mold forming: Pour the ground powder into a mold and use a tablet press to press the powder. The pressure of the tablet press is 20 MPa and the holding time is 10 minutes. During the pressing process, the powder is tightly packed under the pressure to form a green body with a certain strength and shape.

[0145] S4: Sintering treatment: The pressed green body is placed in a sintering furnace and heated to 1100°C at a heating rate of 7.5°C / min, kept at this temperature for 3 hours, and then cooled to room temperature in the furnace. During the sintering process, polymethyl methacrylate and lithium magnesium silicate decompose and volatilize to form a large number of pores, while nano-silica adjusts the uniformity and size of the pores, thereby achieving high porosity.

[0146] S5: Post-processing: After the sintered ceramic film is taken out, the surface is polished as needed; the surface of the film is polished with a diamond grinding wheel to remove burrs and uneven parts on the surface, so that the surface roughness reaches Ra0.3 microns, making the surface of the film smooth.

[0147] In S1 of this embodiment, in the raw material mixing step, after the materials are placed in the ball mill, the speed of the ball mill is controlled to 200 r / min, and the ball milling time is 12.5 hours.

[0148] In the drying and grinding step S2 of this embodiment, the particle size of the powder after grinding is 3 microns, thereby ensuring that the subsequently prepared film has good density and uniformity.

[0149] In S3 of this embodiment, in the mold forming step, the shape and size of the mold are designed according to the final shape of the desired thin film ceramic to meet the needs of different application scenarios.

[0150] Example 4:

[0151] A high-rate thin-film ceramic based on a porous structure, comprising the following components in percentage by mass:

[0152] Alumina: 33%;

[0153] Zirconia: 12%;

[0154] Yttrium oxide: 6%;

[0155] Silicon carbide: 6%;

[0156] Cerium nitrate: 3%;

[0157] Lanthanum nitrate: 3%;

[0158] Lithium magnesium silicate: 5%;

[0159] Polymethyl methacrylate: 12%;

[0160] Nano-silicon dioxide: 6%.

[0161] A method for preparing a high-rate thin-film ceramic based on a porous structure comprises the following steps:

[0162] S1: Raw material mixing: according to the above-mentioned component ratio, aluminum oxide, zirconium oxide, yttrium oxide, silicon carbide, cerium nitrate, lanthanum nitrate, lithium magnesium silicate, polymethyl methacrylate and nano-silica are weighed respectively, and added into a ball mill for mixing, and an appropriate amount of deionized water is added as a dispersion medium; during the ball milling process, the raw material particles are fully mixed under the action of mechanical force, and partially ground at the same time, so that the particle size is reduced and the distribution is more uniform, providing a good foundation for the subsequent preparation process;

[0163] S2: Drying and grinding: The milled slurry is taken out and placed in a drying oven at 63°C for 12 hours to remove moisture and obtain a dry powder. Subsequently, the dried powder is placed in a grinder and ground for 35 minutes to further refine the particles and ensure the uniformity of the powder.

[0164] S3: Mold forming: Pour the ground powder into a mold and use a tablet press to press the powder. The pressure of the tablet press is 15 MPa and the holding time is 6 minutes. During the pressing process, the powder is densely packed under the action of pressure to form a green body with a certain strength and shape.

[0165] S4: Sintering treatment: The pressed green body is placed in a sintering furnace and heated to 1050°C at a heating rate of 6°C / min, kept at this temperature for 2.5 hours, and then cooled to room temperature in the furnace. During the sintering process, polymethyl methacrylate and lithium magnesium silicate decompose and volatilize to form a large number of pores, while nano-silica adjusts the uniformity and size of the pores, thereby achieving high porosity.

[0166] S5: Post-processing: After the sintered ceramic film is taken out, the surface is polished as needed; the surface of the film is polished with a diamond grinding wheel to remove burrs and uneven parts on the surface, so that the surface roughness reaches Ra0.2 microns, making the surface of the film smooth.

[0167] In S1 of this embodiment, in the raw material mixing step, after the materials are placed in the ball mill, the speed of the ball mill is controlled to 170 r / min, and the ball milling time is 11 hours.

[0168] In the drying and grinding step S2 of this embodiment, the particle size of the powder after grinding is 2 microns, thereby ensuring that the subsequently prepared film has good density and uniformity.

[0169] In S3 of this embodiment, in the mold forming step, the shape and size of the mold are designed according to the final shape of the desired thin film ceramic to meet the needs of different application scenarios.

[0170] The high-rate thin-film ceramics based on the porous structure prepared in the above embodiment have the following properties:

[0171]

[0172] Performance test table description:

[0173] 1. Porosity (%): measured by Archimedes drainage method or scanning electron microscopy (SEM) combined with image analysis software.

[0174] 2. Bending strength (MPa): Measured by three-point bending test method, reflecting the material's ability to resist bending.

[0175] 3. Fracture toughness (MPa·m1 / 2): Measured using single-edge pre-crack bending (SENB) specimens, reflecting the material's ability to resist crack growth.

[0176] 4. Thermal conductivity (W / (m·K)): Measured by laser flash method, it reflects the thermal conductivity of the material.

[0177] 5. Surface roughness (Ra) (μm): Measured using a surface roughness meter, reflecting the smoothness of the film surface.

[0178] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0179] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A high-rate thin film ceramic based on a porous structure, characterized in that: The following ingredients are included in percentage by mass: Alumina: 30-50%; Zirconia: 10-20%; Yttrium oxide: 5-15%; Silicon carbide: 5-10%; Cerium nitrate: 2-8%; Lanthanum nitrate: 2-8%; Lithium magnesium silicate: 5-10%; Polymethyl methacrylate: 10-20%; Nano-silicon dioxide: 5-15%.

2. A method for preparing high-rate thin-film ceramics based on a porous structure, characterized in that: The following steps are involved: S1: Raw material mixing: according to the above-mentioned component ratio, aluminum oxide, zirconium oxide, yttrium oxide, silicon carbide, cerium nitrate, lanthanum nitrate, lithium magnesium silicate, polymethyl methacrylate and nano-silica are weighed respectively, and added into a ball mill for mixing, and an appropriate amount of deionized water is added as a dispersion medium; during the ball milling process, the raw material particles are fully mixed under the action of mechanical force, and partially ground at the same time, so that the particle size is reduced and the distribution is more uniform, providing a good foundation for the subsequent preparation process; S2: Drying and grinding: The milled slurry is taken out and placed in a drying oven at 60-80°C for 10-20 hours to remove moisture and obtain a dry powder; then, the dried powder is placed in a grinder and ground for 30-60 minutes to further refine the particles and ensure the uniformity of the powder; S3: Mold forming: Pour the ground powder into a mold and use a tablet press to press the powder. The pressure of the tablet press is 10-30 MPa and the holding time is 5-15 minutes. During the pressing process, the powder is tightly packed under the pressure to form a green body with a certain strength and shape. S4: Sintering treatment: The pressed green body is placed in a sintering furnace and heated to 1000-1200°C at a heating rate of 5-10°C / min, kept at this temperature for 2-4 hours, and then cooled to room temperature with the furnace. During the sintering process, polymethyl methacrylate and lithium magnesium silicate decompose and volatilize to form a large number of pores, while nano-silica adjusts the uniformity and size of the pores, thereby achieving high porosity. S5: Post-processing: After the sintered ceramic film is taken out, the surface is polished as needed; the surface of the film is polished with a diamond grinding wheel to remove burrs and uneven parts on the surface, so that the surface roughness reaches Ra0.1-0.5 microns, making the surface of the film smooth.

3. The method for preparing a high-rate thin-film ceramic based on a porous structure according to claim 2, characterized in that: In the step S1: mixing raw materials, each material is placed in a ball mill, the speed of the ball mill is controlled to be 150-250 r / min, and the ball milling time is 10-15 hours.

4. The method for preparing a high-rate thin film ceramic based on a porous structure according to claim 2, characterized in that: In the drying and grinding step S2, the particle size of the ground powder is 1-5 microns, thereby ensuring that the subsequently prepared film has good density and uniformity.

5. The method for preparing a high-rate thin-film ceramic based on a porous structure according to claim 2, characterized in that: In the step S3: mold forming, the shape and size of the mold are designed according to the final shape of the desired thin film ceramic to meet the needs of different application scenarios.

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