Ceramic pot preparation process

Abstract

The invention discloses a preparation process of a ceramic pot, belongs to the technical field of ceramic preparation, and aims to solve the problem that the thermal conductivity and the cleaning and anti-pollution performance of the ceramic pot are influenced while the durability is reduced by adopting a traditional metal oxide as a sintering aid. The effects of reducing the lattice oxygen content, ensuring the high thermal conductivity and ensuring the durability of the ceramic pot are achieved, and a formula component of # imgabs0 is reasonably configured, so that the relative density of the ceramic pot is improved, and the thermal conductivity is further improved; the surface of the prepared ceramic pot has a # imgabs 1 # nano covering layer film structure, F atoms in the micro-structure # imgabs 2 # particles with surface net-like structures cover the whole molecular chain surface, the environment of acid, alkali and organic solvents can be resisted, stability is still kept under high-temperature cooking or washing reagents, falling and stripping are avoided, and the service life of the ceramic pot is prolonged. Therefore, the ceramic pot is endowed with clean anti-pollution performance and durability.

Description

Technical Field

[0001] The invention discloses a ceramic preparation technology, in particular to a ceramic pot preparation process. Background Art

[0002] In order to meet people's cooking needs of retaining food nutrition, ceramic pots are becoming more and more popular. In the daily use of ceramic pots, their heat resistance, anti-fouling and easy cleaning properties are a key point in judging the quality of ceramic pots.

[0003] Most of the existing ceramic pots have heat resistance, but the surface depends on the coating. However, the stability of the coating changes under the cleaning agents such as detergents. In this case, scratches can easily damage the coating, causing the cleaning and anti-fouling performance to be greatly reduced. Summary of the invention

[0004] The purpose of the present invention is to provide a ceramic pot preparation process in order to solve the above-mentioned problems.

[0005] To achieve the above object, the present invention provides the following technical solution: a ceramic pot preparation process, comprising the following steps:

[0006] S1, according to the following mass parts: 70-90 parts of silicon nitride powder , 5-20 servings , 1-3 servings , 0-1 , 5 As raw materials, they are put into the ball mill and the ball mill ratio is 2:1. Ceramic balls were used as ball milling media, ethanol was used as dispersant, and continuous ball milling and wet mixing were performed for 24 hours to obtain a wet mixed material;

[0007] S2, placing the wet mixture in a vacuum drying oven at 60°C for 12 hours to obtain a dry mixture, passing the dry mixture through a 60-mesh sieve to obtain a raw material mixture, placing the raw material mixture into a pot-shaped mold, and performing dry pressing of the raw material mixture in the pot-shaped mold by a press to obtain a green body, placing the green body into a hot pressing sintering furnace for sintering, and filling , The gas pressure is 0.9 MPa. The initial sintering temperature is increased from room temperature to 1600°C at a heating rate of 15°C / min and maintained for 1 hour. The sintering chamber is pressurized with 30 MPa and increased to 1800°C at a heating rate of 10°C / min and maintained for 4 hours. The heating is stopped and the mixture is naturally cooled to room temperature and maintained for 1 hour to obtain a ceramic pot embryo.

[0008] S3, after heating the ceramic pot embryo to 80-90°C, a five-axis five-linkage laser etcher is used to perform laser etching on the surface of the ceramic pot embryo to form regularly arranged imitation square holes, the etching number of the laser etcher is 5 times, the width and spacing of the etched imitation square holes are 50-200μm, the wavelength of the laser etcher is 1064nm, the etching frequency is 50w, the wire speed is 800mm / s, and the laser opening delay parameter is -200μs;

[0009] S4, placing the etched ceramic pot embryo body into a carbon-carbon deposition furnace, depositing nano-carbon particles in the imitation square holes on the surface of the ceramic pot embryo body through a CVD process, taking the ceramic pot embryo body out of the carbon-carbon deposition furnace and placing it in a vacuum chamber, placing an ammonia-isopropanol solution and the ceramic pot embryo body in the same vacuum drying container, wherein the volume fraction of ammonia in the solution is 28%, and the mass ratio of the ammonia-isopropanol solution to the ceramic pot embryo body is 1:10, using a vacuum pump to evacuate the vacuum chamber, and then adding 99.99% ethyl orthosilicate solution to perform a Stober reaction, after keeping it in the drying container under vacuum for 24 hours, placing the ceramic pot embryo body in a heating furnace and heating it at 600°C for 2 hours;

[0010] S5, taking the ceramic pot embryo out of the heating furnace, cooling it, and placing it in a drying container, adding 98% 1H,1H,2H,2H-perfluorooctyltrichlorosilane solution and letting it stand for 3 hours, and performing low surface energy treatment at the same time to obtain a ceramic pot with an anti-fouling coating.

[0011] Preferably, in S1, silicon nitride powder 85 copies were used. Use 10 copies.

[0012] Preferably, in S1, Use 3 copies, Use 1 copy, Use 5 copies.

[0013] Preferably, in S3, the width and spacing of the etched pseudo-square holes are 200 μm and 50 μm respectively.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] First, compared with the use of traditional metal oxides as sintering aids, which reduces the durability and affects the thermal conductivity and cleaning and anti-fouling performance of the ceramic pot, the present invention uses metal hydrides as sintering aids to reduce the lattice oxygen content and ensure high thermal conductivity to ensure the durability of the ceramic pot, and the configuration is reasonable. and The formula components increase the relative density of the ceramic pot and further improve the thermal conductivity;

[0016] Secondly, the surface of the ceramic pot prepared by the present invention has Nano-covering film structure, with micron-scale microstructure, and The nano-coating membrane structure has a reticular structure. In terms of microstructure, during high-temperature cooking in a ceramic pot, three different interfacial tensions of solid-liquid-gas are formed on the surface. The F atoms in the particles cover the entire surface of the molecular chain and can withstand the acid, alkali and organic solvent environment. They remain stable without falling off or peeling off under high-temperature cooking or detergent reagents, thus giving the ceramic pot cleaning, anti-fouling and durability properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A chart showing the relative density of ceramic pots corresponding to the number of servings used in the four recipes;

[0018] Figure 2 This is a chart showing the effect of the number of servings used in four recipes on the thermal conductivity of ceramic pots;

[0019] Figure 3 A chart showing the relative density of ceramic pots corresponding to the number of servings used in the four recipes;

[0020] Figure 4 The graphs showing the influence of the number of portions used in the four recipes on the lattice oxygen content and the thermal conductivity of the ceramic pot;

[0021] Figure 5 Schematic diagram of the microstructure of the imitation square hole;

[0022] Figure 6 Schematic diagram of the microstructure of the porous membrane layer inside and at the bottom of the simulated square hole;

[0023] Figure 7 Simplified flow chart for the antifouling coating formation process. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, which are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments in 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.

[0025] In traditional technology, it is often used As a sintering aid, but studies have shown that silicon nitride powder by When used as a sintering aid, it will limit the sintering densification process of the ceramic pot, reduce durability and affect the thermal conductivity and cleaning and anti-fouling properties of the ceramic pot.

[0026] A ceramic pot preparation process comprises the following steps:

[0027] S1, according to the following mass parts: 70-90 parts of silicon nitride powder , 10-20 servings , 1-3 servings , 0-1 , 5 As raw materials, they are put into the ball mill and the ball mill ratio is 2:1. Ceramic balls were used as ball milling media, ethanol was used as dispersant, and continuous ball milling and wet mixing were performed for 24 hours to obtain a wet mixed material;

[0028] S2, placing the wet mixture in a vacuum drying oven at 60°C for 12 hours to obtain a dry mixture, passing the dry mixture through a 60-mesh sieve to obtain a raw material mixture, placing the raw material mixture into a pot-shaped mold, and performing dry pressing of the raw material mixture in the pot-shaped mold by a press to obtain a green body, placing the green body into a hot pressing sintering furnace for sintering, and filling , The gas pressure is 0.9 MPa. The initial sintering temperature is increased from room temperature to 1600°C at a heating rate of 15°C / min and maintained for 1 hour. The sintering chamber is pressurized with 30 MPa and increased to 1800°C at a heating rate of 10°C / min and maintained for 4 hours. The heating is stopped and the mixture is naturally cooled to room temperature and maintained for 1 hour to obtain a ceramic pot embryo.

[0029] Embodiment 1

[0030] In S1, silicon nitride powder and The following four groups of formula portions are used respectively:

[0031] Ⅰ, , : 90 copies, 5 copies;

[0032] II, , : 85 parts 10 parts;

[0033] III, , : 80 copies, 15 copies;

[0034] IV, , : 75 copies, 20 copies;

[0035] The ceramic pots sintered with the above four groups of recipes were sampled and the raw material composition in the spectrum was analyzed by XRD scanning. The composition ratio is used as a relative density measure, such as Figure 1 The figure shows the relative density of the ceramic pot corresponding to the number of portions of the four recipes. By comparing recipes Ⅰ-Ⅳ, it can be found that as The addition amount was increased from 5 to 20 parts at a time. The relative density of the ceramic pot samples increased first and then decreased. The maximum value is reached when the addition amount is 10 parts. The influencing factors are analyzed as follows: during the sintering process of the ceramic pot, the low addition amount It helps to improve the dissolution and precipitation of grains and inhibit particle rearrangement, but excessive , due to its relatively large single crystal size If the size is large, the space around the grains will become smaller, the distribution density will be reduced, and the relative density of the ceramic pot will be reduced;

[0036] like Figure 2 The following is a graph showing the influence of the number of portions used in four groups of recipes on the thermal conductivity of ceramic pots. By comparing recipes Ⅰ-Ⅳ, it can be found that as The amount of addition is increased from 5 parts to 20 parts at a time, and the corresponding thermal conductivity increases first and then decreases. The maximum value is reached when the addition amount is 10 parts. The influencing factors are analyzed. During the sintering process of ceramic pot, It can regulate the grain growth. When the addition amount is less than 10 parts, The presence of high density dislocations leads to higher thermal conductivity, while excessive The high-density dislocations are eliminated, which increases the defects inside the grains and reduces the thermal conductivity. In summary, formula II is selected: silicon nitride powder 85 copies were used. Use 10 copies.

[0037] Embodiment 2:

[0038] Using the formula II of Example 1, in S1, , , The following four groups of formula portions are used respectively:

[0039] ① , , : 1 copy, 0 copy, 0 copy;

[0040] ② , , : 2 copies, 1 copy, 0 copies;

[0041] ③ , , : 3 copies, 1 copy, 0 copies;

[0042] ④ , , : 3 portions, 1 portion, 5 portions;

[0043] The ceramic pots sintered with the above four groups of recipes were sampled and tested. Figure 3 The following is a chart showing the relative density of the ceramic pot according to the number of portions used in the four recipes. By comparing ①-③, it can be found that as The addition amount increased from 1 to 3 parts, and the relative density of the ceramic pot samples showed a trend of first increasing and then decreasing. The influencing factors were analyzed as follows: Quantity and The effect of the ratio increases the reaction rate of Si and N elements. The amount of front-end reactants can increase the reaction rate, but the same reaction products and The amount of It can react with the free oxygen in the product, thereby increasing the reaction rate of the front-end reaction, thereby increasing the relative density of the ceramic pot. When more than 2 parts are added, The ratio increases, hindering the densification of the ceramic pot, thus affecting the density of the ceramic pot; such as Figure 4 The following is a graph showing the influence of the number of parts used in the four groups of formulas on the lattice oxygen content and the thermal conductivity of the ceramic pot. By comparing formulas ①-③, it can be found that as The addition amount of is increased from 1 to 3 parts, and the corresponding lattice oxygen content is reduced from 0.050 WT% to 0.025 WT%. In formula ④, only the change When the content of lattice oxygen changes from 0 to 5, the corresponding lattice oxygen content becomes 0.020 WT%, and the thermal conductivity of 98 W / (M·K) can be obtained. This is because The thermal conductivity of the ceramic pot itself exceeds that of the ceramic pot materials, and can inhibit the sintering process The amount of lattice oxygen content is low while having high thermal conductivity, which improves the durability of the ceramic pot;

[0044] Compared with the use of traditional metal oxides as sintering aids, which reduces the durability and affects the thermal conductivity and cleaning and anti-fouling performance of the ceramic pot, the use of metal hydrides can reduce the lattice oxygen content and ensure high thermal conductivity to ensure the durability of the ceramic pot. In summary, formula ④ is selected: Use 3 copies, Use 1 copy, Use 5 copies.

[0045] Embodiment 3

[0046] S3, after heating the ceramic pot embryo to 80-90°C, a five-axis five-linkage laser etcher is used to perform laser etching on the surface of the ceramic pot embryo to form regularly arranged imitation square holes, the etching number of the laser etcher is 5 times, the width and spacing of the etched imitation square holes are 50-200μm, the wavelength of the laser etcher is 1064nm, the etching frequency is 50w, the wire speed is 800mm / s, and the laser opening delay parameter is -200μs;

[0047] S4, placing the etched ceramic pot embryo body into a carbon-carbon deposition furnace, depositing nano-carbon particles in the imitation square holes on the surface of the ceramic pot embryo body through a CVD process, taking the ceramic pot embryo body out of the carbon-carbon deposition furnace and placing it in a vacuum chamber, placing an ammonia-isopropanol solution and the ceramic pot embryo body in the same vacuum drying container, wherein the volume fraction of ammonia in the solution is 28%, and the mass ratio of the ammonia-isopropanol solution to the ceramic pot embryo body is 1:10, using a vacuum pump to evacuate the vacuum chamber, and then adding 99.99% ethyl orthosilicate solution to perform a Stober reaction, after keeping it in the drying container under vacuum for 24 hours, placing the ceramic pot embryo body in a heating furnace and heating it at 600°C for 2 hours;

[0048] S5, taking the ceramic pot embryo out of the heating furnace, cooling it, and placing it in a drying container, adding 98% 1H,1H,2H,2H-perfluorooctyltrichlorosilane solution and letting it stand for 3 hours, and performing low surface energy treatment at the same time to obtain a ceramic pot with an anti-fouling coating.

[0049] The process of forming the antifouling coating is simplified as follows Figure 7As shown in the figure, the nano-carbon particles are evenly covered on the surface of the imitation square holes, and the size of the nano-carbon particles is smaller than that of the particles on the surface of the ceramic pot body, while most of the nano-carbon particles are deposited at the bottom of the imitation square holes. When immersed in the ethyl orthosilicate solution and subjected to the Stober reaction, a nano-silicon dioxide particle covering layer is formed, which is consistent with the ceramic pot. The particles are connected and treated with a low surface energy of 1H,1H,2H,2H-perfluorooctyltrichlorosilane solution to form a uniform Nano-covering film structure, The nano-coating film structure has a low friction coefficient and high-temperature stability, and can form a smooth dielectric film structure on the surface of the ceramic pot. When the ceramic pot is heated, the ceramic pot expands due to the heat, and the microstructure of the ceramic pot surface becomes denser. The oil can fill the pores of the dielectric film structure, reducing the adhesion of the ceramic pot to food during cooking, thereby improving the anti-fouling and easy-to-clean performance of the ceramic pot. When the temperature of the ceramic pot drops, the pores of the dielectric film structure become smaller, and the oil droplets are squeezed out or taken away by the detergent without being contaminated by oil. It has high chemical stability, heat resistance, corrosion resistance and wear resistance. During daily use, it will not change its stability under detergents and other cleaning agents, which will not cause scratches and damage to the dielectric film structure, resulting in a significant decrease in cleaning and anti-fouling performance.

[0050] The laser etching process is used to form regularly arranged imitation square holes on the surface of the ceramic pot embryo. The microscopic image of the ceramic pot sample is observed through focusing microscopy. Under the geometric microscopic view, the anti-fouling coating on the surface of the ceramic pot is as follows: Figure 5 The following are the regularly arranged pseudo-square holes. Figure 6 As shown in the figure, a uniform porous film layer is formed. The following Table 1 is a graph of the surface contact angle and rolling contact angle of the etched simulated square holes at different widths and spacings.

[0051] Table 1 Surface contact angle and rolling contact angle diagram of etched square holes with different widths and spacings

[0052] Sample No. Width of etched square hole / μm Etching simulated square hole spacing / μm Surface contact angle / ° Rolling contact angle / ° 1 100 50 153 2.6 2 150 50 158 3.0 3 200 50 155 2.8

[0053] When the width of the etched simulated square hole is less than 100 μm, the edge of the simulated square hole has loose burrs, and it is difficult to form a uniform nano-silicon dioxide particle covering layer in S4. Therefore, a width of at least 100 μm is adopted. When the spacing of the simulated square holes exceeds or is less than 50 μm, the nano-silicon dioxide particle covering layer appears too thick or too thin, which makes the mechanical structure strength of the nano-silicon dioxide particle covering layer formed in S4 low and easily damaged. Therefore, a spacing of 50 μm is selected. When the width of the etched simulated square hole is 10 From 0μm to 200μm, although the etched simulated square holes accommodate more nano-silica particle covering layers, the surface contact angle and rolling contact angle first increase and then decrease with the increase of width. However, after exceeding 150μm, the adhesion between the nano-silica particle covering layer and the outer wall of the etched simulated square holes decreases, which destroys the network structure of the nano-silica particle covering layer and causes the structural strength to decrease. In summary, the scheme of etched simulated square hole width of 150μm and etched simulated square hole spacing of 50μm is selected.

[0054] The surface of the ceramic pot prepared by the present invention has Nano-covering film structure, with micron-scale microstructure, and The nano-coating membrane structure has a reticular structure. In terms of microstructure, during high-temperature cooking in a ceramic pot, three different interfacial tensions of solid-liquid-gas are formed on the surface. The F atoms in the particles cover the entire surface of the molecular chain and can withstand the acid, alkali and organic solvent environment. They remain stable without falling off or peeling off under high-temperature cooking or detergent reagents, thus giving the ceramic pot cleaning, anti-fouling and durability properties.

[0055] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0056] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A process for preparing a ceramic pot, characterized in that: The following steps are involved: S1, according to the following mass parts: 70-90 parts of silicon nitride powder , 5-20 servings , 1-3 servings , 0-1 , 5 As raw materials, they are put into the ball mill and the ball mill ratio is 2:

1. Ceramic balls were used as ball milling media, ethanol was used as dispersant, and continuous ball milling and wet mixing were performed for 24 hours to obtain a wet mixed material; S2, placing the wet mixture in a vacuum drying oven at 60°C for 12 hours to obtain a dry mixture, passing the dry mixture through a 60-mesh sieve to obtain a raw material mixture, placing the raw material mixture into a pot-shaped mold, and performing dry pressing of the raw material mixture in the pot-shaped mold by a press to obtain a green body, placing the green body into a hot pressing sintering furnace for sintering, and filling , The gas pressure is 0.9 MPa. The initial sintering temperature is increased from room temperature to 1600°C at a heating rate of 15°C / min and maintained for 1 hour. The sintering chamber is pressurized with 30 MPa and increased to 1800°C at a heating rate of 10°C / min and maintained for 4 hours. The heating is stopped and the mixture is naturally cooled to room temperature and maintained for 1 hour to obtain a ceramic pot embryo. S3, after heating the ceramic pot embryo to 80-90°C, a five-axis five-linkage laser etcher is used to perform laser etching on the surface of the ceramic pot embryo to form regularly arranged imitation square holes, the etching number of the laser etcher is 5 times, the width and spacing of the etched imitation square holes are 50-200μm, the wavelength of the laser etcher is 1064nm, the etching frequency is 50w, the wire speed is 800mm / s, and the laser opening delay parameter is -200μs; S4, placing the etched ceramic pot embryo body into a carbon-carbon deposition furnace, depositing nano-carbon particles in the imitation square holes on the surface of the ceramic pot embryo body through a CVD process, taking the ceramic pot embryo body out of the carbon-carbon deposition furnace and placing it in a vacuum chamber, placing an ammonia-isopropanol solution and the ceramic pot embryo body in the same vacuum drying container, wherein the volume fraction of ammonia in the solution is 28%, and the mass ratio of the ammonia-isopropanol solution to the ceramic pot embryo body is 1:10, using a vacuum pump to evacuate the vacuum chamber, and then adding 99.99% ethyl orthosilicate solution to perform a Stober reaction, after keeping it in the drying container under vacuum for 24 hours, placing the ceramic pot embryo body in a heating furnace and heating it at 600°C for 2 hours; S5, taking the ceramic pot embryo out of the heating furnace, cooling it, and placing it in a drying container, adding 98% 1H,1H,2H,2H-perfluorooctyltrichlorosilane solution and letting it stand for 3 hours, and performing low surface energy treatment at the same time to obtain a ceramic pot with an anti-fouling coating.

2. A ceramic pot preparation process according to claim 1, characterized in that: In S1, silicon nitride powder 85 copies were used. Use 10 copies.

3. A ceramic pot preparation process according to claim 1, characterized in that: In S1, Use 3 copies, Use 1 copy, Use 5 copies.

4. A ceramic pot preparation process according to claim 1, characterized in that: In S3, the width and spacing of the etched pseudo-square holes are 150 μm and 50 μm, respectively.

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