Preparation method of low-temperature-resistant composite ceramic material

Abstract

The invention provides a preparation method of a low-temperature-resistant composite ceramic material, and relates to the technical field of ceramic material preparation. The preparation method of the low-temperature-resistant composite ceramic material specifically comprises the following steps: S1, preparing a ceramic bonding phase raw material; s2, preparing a ceramic precursor: treating the ceramic binding phase raw material by adopting a sol-gel method to prepare the ceramic precursor with a nanoscale uniform dispersion phase; s3, hot pressed sintering: carrying out hot pressed sintering treatment on the ceramic precursor to obtain a ceramic matrix; s4, surface treatment is conducted, specifically, the surface of the ceramic matrix is filled with high-strength aluminum alloy micron particles, so that the high-strength aluminum alloy micron particles are evenly distributed and tightly combined with the ceramic matrix, and a compact protection layer is formed; and S5, forming a protective layer: winding a PE material on the outer ring of the ceramic matrix subjected to surface treatment to prepare the low-temperature-resistant composite ceramic material. The stability and durability of the material in an extreme environment are enhanced, and the interface bonding strength and the comprehensive performance are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ceramic material preparation, in particular to a preparation method of low-temperature-resistant composite ceramic material. BACKGROUND

[0002] In an extremely low-temperature environment (such as-60℃ and below), traditional ceramic materials are prone to brittle fracture or structural failure due to their high brittleness and poor thermal shock resistance, and are difficult to meet the stringent requirements of weapon equipment (such as tank armor), engineering components in extremely cold regions, and the like on low-temperature resistance, impact resistance, and long-term stability.

[0003] Existing low-temperature ceramic materials are mostly based on a single system (such as silicate ceramic), and there are some deficiencies in the preparation process. For example, the wettability of the ceramic bonding phase and the reinforcing phase (such as diamond) is poor, the interfacial bonding strength is low, which leads to the material being prone to interfacial peeling due to stress concentration at low temperature, affecting the overall mechanical properties; the ceramic material prepared by traditional process has low density and many micro defects, and is prone to crack propagation and performance degradation under complex working conditions such as high-low temperature cycling and chemical corrosion, making it difficult to ensure long-term stable operation; although the pure hot-pressing sintering method can improve the density, the cost is high; and although the low-temperature synthesis process such as sol-gel method can control the microstructure, it is difficult to realize the rapid densification of the material, resulting in low production efficiency and poor performance uniformity.

[0004] Therefore, developing a preparation method of composite ceramic material that can balance low-temperature resistance, interfacial bonding strength, extreme environment resistance, and preparation economy has become the key to solving the above technical problems. SUMMARY

[0005] (I) Technical problems solved

[0006] In view of the deficiencies of the prior art, the present application provides a preparation method of low-temperature-resistant composite ceramic material, which solves the problems of brittle fracture, poor interfacial bonding, weak extreme environment resistance of traditional ceramic in extremely cold environment, and difficulty in balancing process cost and performance.

[0007] (II) Technical solutions

[0008] To achieve the above purpose, the present application is implemented by the following technical solutions: a preparation method of low-temperature-resistant composite ceramic material, specifically comprising the following steps:

[0009] S1. Preparing ceramic bonding phase raw material: taking Na2O-B2O3-SiO2 system as low-temperature ceramic matrix, adding 5-7% of ZnO and 10-15% of Al2O3 to it, and mixing uniformly to form ceramic bonding phase raw material;

[0010] S2. Preparing ceramic precursor: treating the ceramic binder phase raw material by sol-gel method to prepare ceramic precursor with nanoscale uniform dispersion phase, the particle size of the nanoscale uniform dispersion phase is 50-80nm;

[0011] S3. Hot-pressing sintering: hot-pressing sintering treatment is performed on the ceramic precursor, the pressure of hot-pressing sintering is 600-800T, to obtain ceramic matrix;

[0012] S4. Surface treatment: filling high-strength aluminum alloy microparticles on the surface of the ceramic matrix, so that the high-strength aluminum alloy microparticles are uniformly distributed and tightly combined with the ceramic matrix to form a dense protective layer;

[0013] S5. Forming protective layer: winding PE material on the outer circle of the ceramic matrix after surface treatment, the thickness of the PE material is 0.1mm, the winding mode is 10 horizontal turns and 10 vertical turns, and then high-temperature heating and fusion are performed to form a firm protective layer, to obtain a low-temperature-resistant composite ceramic material.

[0014] Preferably, in S3, during the hot-pressing sintering process, as the temperature rises and the holding time extends, the surface tension of the ceramic binder phase melt is controlled to be smaller, so that the wetting angle of the ceramic binder phase to the diamond is smaller.

[0015] Preferably, in S1, the ceramic binder phase raw material further includes diamond and silicon nitride, which is used to improve the thermal conductivity of the ceramic binder phase.

[0016] Preferably, during the hot-pressing sintering process, new chemical bonds are formed at the diamond / ceramic binder phase interface to ensure the holding force of the binder phase to the diamond particles.

[0017] Preferably, in S5, the temperature of high-temperature heating and fusion is controlled within the temperature range that makes the PE molecular chain closely arranged, so as to improve the heat resistance and chemical corrosion resistance of the material.

[0018] (Three) beneficial effects

[0019] The application provides a low-temperature-resistant composite ceramic material preparation method, which has the following beneficial effects:

[0020] 1. The application provides a low-temperature-resistant composite ceramic material preparation method, which comprises the following steps: precisely adding 5-7% of ZnO and 10-15% of Al2O3 in a Na2O-B2O3-SiO2 system, combining a sol-gel method (controlling the uniform distribution of 50-80 nm nano-dispersed phase) and a hot-pressing sintering (600-800T pressure) composite process, effectively improving the wettability and interface bonding strength of the ceramic bonding phase and the reinforcing phase. Meanwhile, the synergistic effect of high-strength aluminum alloy microparticle filling and PE protective layer makes the dynamic impact strength of the material remain above 90% of the room temperature value in an extremely cold environment of-60 DEG C, and the compression strength attenuation rate is less than 5% after 500 high-low temperature cycles, significantly improving the brittle fracture resistance and long-term stability in extreme environments.

[0021] 2. The application provides a low-temperature-resistant composite ceramic material preparation method, which comprises the following steps: preparing a nano-scale uniformly dispersed phase ceramic precursor by a sol-gel method, precisely controlling the raw material component ratio and microstructure, laying a foundation for the low-temperature toughness of the material; combining a hot-pressing sintering technology to realize rapid densification, effectively inhibiting abnormal grain growth and reducing interface defects, improving the material density and mechanical properties (the bending strength is improved by more than 30%, and the fracture toughness is improved by 25%), reducing the preparation cost by about 20% compared with the pure hot-pressing sintering method, realizing the effective balance of high performance and economy, and being suitable for large-scale industrial production and application requirements in many fields such as weapons and equipment and extremely cold engineering. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the application will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the application.

[0023] The low-temperature-resistant composite ceramic material preparation method of the application will be described in detail through specific embodiments. The raw material ratios in the embodiments are in mass fraction, and the process parameters are compared and presented in the table.

[0024] Raw material composition and process parameters of examples 1-3 and comparative example 1

[0025]

[0026]

[0027] Specific preparation steps of example 1

[0028] Preparation of ceramic binder phase raw material: according to the proportions in the above table for example 1, the Na2O-B2O3-SiO2system raw material is mixed with 5% ZnO and 10% Al2O3, and an appropriate amount of diamond and silicon nitride (mass ratio of 15% and 8% respectively) is added, and after stirring uniformly, the ceramic binder phase raw material is obtained.

[0029] Preparation of ceramic precursor: the above raw materials are treated by sol-gel method, and by controlling the reaction temperature (60℃) and stirring rate (300r / min), a nano-sized uniformly dispersed phase ceramic precursor with a particle size of 50nm is prepared.

[0030] Hot-pressing sintering: the precursor is placed in a hot-pressing sintering furnace, heated to 850℃ at a rate of 5℃ / min under a pressure of 600T, and sintered for 2h to obtain a ceramic matrix.

[0031] Surface treatment: high-strength aluminum alloy microparticles (particle size 5-10μm) are uniformly spread on the surface of the ceramic matrix, and the particles are embedded into the surface of the matrix by ultrasonic vibration (power 500W, time 10min) to form a dense protective layer.

[0032] Formation of PE protective layer: the PE material is wound according to the parameters of 0.1mm thick, 10 horizontal turns and 10 vertical turns, heated and fused at 120℃ for 30min, and after cooling, a low-temperature resistant composite ceramic material is obtained.

[0033] Preparation steps of examples 2-3

[0034] The preparation steps of examples 2-3 are consistent with example 1, only the raw material proportions and process parameters are adjusted according to the corresponding groups in the above table (such as the hot-pressing sintering temperature of example 2 is 880℃, and the holding time is 2.5h; the hot-pressing sintering temperature of example 3 is 900℃, and the holding time is 3h).

[0035] Performance test results

[0036] The materials prepared in examples 1-3 and comparative example 1 are tested for performance, and the results are as follows:

[0037]

[0038] As can be seen from the above table, the low-temperature resistant composite ceramic material prepared by the method of the present application (examples 1-3) has a dynamic impact strength at-60℃ of more than 90% of the room temperature value, a compression strength attenuation rate of less than 5% after 500 high-low temperature cycles, a bending strength improved by more than 30% compared with the traditional process (comparative example 1), and a preparation cost reduced by more than 20%, which is significantly better than traditional ceramic materials, fully verifying the effectiveness and superiority of the method. Among them, example 2 has the best comprehensive performance due to the synergistic optimization of the addition proportions of ZnO and Al2O3 and the hot-pressing sintering parameters.

[0039] While embodiments of the application have been shown and described, it is to be understood that the application is not limited to the details of the embodiments described, since numerous changes, modifications, substitutions and variations can be made thereto without departing from the spirit and scope of the application as defined by the appended claims and their equivalents.

Claims

1. A method for preparing low-temperature resistant composite ceramic materials, characterized in that, Specifically, the following steps are included: S1. Preparation of ceramic bonding phase raw materials: Using the Na2O-B2O3-SiO2 system as the low-temperature ceramic matrix, add 5-7% ZnO and 10-15% Al2O3 to it, and mix them evenly to form ceramic bonding phase raw materials; S2. Preparation of ceramic precursor: The ceramic bonding phase raw material is processed by sol-gel method to prepare a ceramic precursor with a nanoscale uniformly dispersed phase, wherein the particle size of the nanoscale uniformly dispersed phase is 50-80 nm. S3. Hot pressing sintering: The ceramic precursor is subjected to hot pressing sintering treatment at a pressure of 600-800T to obtain a ceramic matrix; S4. Surface treatment: High-strength aluminum alloy micron particles are filled on the surface of the ceramic substrate to make the high-strength aluminum alloy micron particles evenly distributed and tightly bonded to the ceramic substrate to form a dense protective layer. S5. Forming a protective layer: PE material with a thickness of 0.1 mm is wound around the surface-treated ceramic substrate in a winding pattern of 10 horizontal turns and 10 vertical turns. Then, high-temperature heating is performed to fuse the layers and form a robust protective layer, thus obtaining a low-temperature resistant composite ceramic material.

2. The method for preparing low-temperature resistant composite ceramic materials according to claim 1, characterized in that: In S3, during the hot pressing sintering process, as the temperature increases and the holding time is extended, the surface tension of the ceramic bonding phase melt is reduced, thereby reducing the wetting angle of the ceramic bonding phase against diamond.

3. The method for preparing low-temperature resistant composite ceramic materials according to claim 1, characterized in that: In step S1, the ceramic bonding phase raw material further includes diamond and silicon nitride, which are used to improve the thermal conductivity of the ceramic bonding phase.

4. The method for preparing low-temperature resistant composite ceramic materials according to claim 1, characterized in that: During the hot pressing sintering process, new chemical bonds are formed at the diamond / ceramic bonding phase interface to ensure the bonding phase's holding force on the diamond particles.

5. The method for preparing low-temperature resistant composite ceramic materials according to claim 1, characterized in that: In S5, the temperature of the high-temperature heating and fusion is controlled within the temperature range that allows the PE molecular chains to be closely arranged, so as to improve the heat resistance and chemical corrosion resistance of the material.

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