Cooking appliance and manufacturing method therefor

Abstract

A cooking appliance (10) and a manufacturing method therefor. The cooking appliance (10) comprises a cooking container provided with a cooking cavity; the cooking cavity is defined by the bottom wall and the side wall of the cooking container; a carbon substrate (101) constitutes the bottom wall, or the carbon substrate (101) constitutes the bottom wall and at least part of the side wall; the carbon substrate (101) comprises a carbonaceous skeleton, and an amorphous carbon material and a mineral material which are filled in the gap of the carbonaceous skeleton; a graphite substrate (103) is arranged on a part of the surface of the carbon substrate (101) or inside the carbon substrate (101); an organic carbonization layer (102) is arranged between the carbon substrate (101) and the graphite substrate (103); the coefficient of thermal conductivity of the carbon substrate (101) is less than the coefficient of thermal conductivity of the graphite substrate (103); the expansion coefficient of the carbon substrate (101) is greater than the expansion coefficient of the organic carbonization layer (102); and the expansion coefficient of the organic carbonization layer (102) is greater than the expansion coefficient of the graphite substrate (103). According to the cooking appliance (10), various heating modes such as electromagnetic heating can be realized, the heating effect can be improved, and the risks of heating and cracking and the like are reduced.

Description

[0001] FIELD OF THE INVENTION The present invention relates to the field of household electrical appliances, and in particular to a cooking vessel and a method for preparing the same. Background Art: As people's living standards continue to improve, demands for food safety and health are also increasing. Cooking vessels, as essential kitchen utensils in daily life, must meet certain safety and health requirements. Traditional cooking vessels made of iron and stainless steel, while stable and reliable, can release harmful substances such as iron and arsenic ions, which can have certain impacts on human health. Therefore, in recent years, a number of new materials have been widely researched and applied in cooking vessels to meet people's demands for safety and health. Among them, amorphous carbon materials, as a new type of material, have attracted considerable attention in the field of cooking vessels. Amorphous carbon materials are carbonaceous materials characterized by a loose structure, high porosity, and a large specific surface area, resulting in excellent adsorption and catalytic properties. In cooking vessels, amorphous carbon materials can regulate water quality, release minerals, and provide far-infrared heating, thereby improving cooking results. For example, when applied to the inner pot of an electric rice cooker, it can improve the texture of rice, making it softer, more tender, and sweeter. When applied to the inner pot of an electric stew pot, it can enhance the quality of soup, making it thicker, fresher, and more fragrant. However, high-end electric rice cookers and conventional induction cookers, along with other cooking utensils, use electromagnetic heating technology, which rapidly heats the inner pot with extremely high thermal efficiency. This heating process also creates a high and low temperature differential across the inner pot, allowing food to tumble and heat more evenly. However, amorphous carbon materials are non-conductive and thus cannot undergo electromagnetic heating, effectively achieving high and low temperature heating, thereby preventing the food from tumbling and boiling. SUMMARY OF THE INVENTION To address these issues, it is necessary to provide a cooking vessel and a method for preparing the same. The cooking vessel, when used in a cooking appliance, can implement multiple heating methods, including electromagnetic heating, not only improving heating efficiency but also reducing the risk of cracking of heatable components. A cooking vessel, for use in cooking utensils, comprising a cooking vessel having a cooking cavity, the cooking vessel comprising a bottom wall and side walls, the bottom wall and the side walls together forming the cooking cavity, wherein the bottom wall is formed by a carbon matrix, or the bottom wall and at least a portion of the side walls are formed by a carbon matrix, the carbon matrix comprising a carbonaceous skeleton and amorphous carbon material and mineral material filling gaps within the carbonaceous skeleton, a graphite matrix being disposed on a portion of the surface or within the interior of the carbon matrix, and a carbonized organic layer being disposed between the carbon matrix and the graphite matrix; the cooking vessel further satisfies the following conditions:

[0002] (1) The thermal conductivity of the carbon matrix is ​​lower than that of the graphite matrix; (2) The expansion coefficient of the carbon matrix is ​​higher than that of the organic carbonized layer, and the expansion coefficient of the organic carbonized layer is higher than that of the graphite matrix. The cooking vessel of the present invention has a unique structure. On the one hand, it can realize a variety of heating methods such as electromagnetic heating. On the other hand, during the heating process, since the thermal conductivity of the graphite matrix is ​​higher than that of the carbon matrix, and the thermal conductivity area of ​​the carbon matrix is ​​larger than that of the graphite matrix, a temperature difference between hot and cold is formed on the heating surface, thereby achieving effective high and low temperature heating, accelerating heat convection and tumbling of the heated material, and thus improving the heating effect. In addition, the thermal expansion coefficients between the carbon matrix, the organic carbonized layer, and the graphite matrix form a gradient, which has a transition effect, making the overall stress controllable during the heating process, which is beneficial to reducing the risk of cracking of the cooking vessel due to heat. At the same time, the cooking vessel also has the advantages of high hardness, not easy to blacken, and good heat storage effect of amorphous carbon, which is beneficial to improving the cooking effect. In one embodiment, the carbon substrate has a groove on its surface, and the graphite substrate is positioned within the groove; alternatively, the carbon substrate has a cavity within its interior, and the graphite substrate is positioned within the cavity. Embedding the graphite substrate within the carbon substrate not only improves thermal conductivity but also reduces the exposed surface area of ​​the graphite, improving issues such as blackening of the graphite surface. In one embodiment, the depth of the groove or cavity is no greater than two-thirds of the thickness of the carbon substrate. Adjusting the groove depth not only improves electromagnetic heating but also maintains high strength on the surface of the carbon substrate, preventing defects such as cracks during heating. In one embodiment, the carbon substrate meets at least one of the following conditions:

[0003] (1) The expansion coefficient of the carbon matrix is ​​4×10′ 6 / °C-6X 10- 6 / °C;

[0004] (2) the porosity of the carbon matrix is ​​greater than 6%;

[0005] (3) The thermal conductivity of the carbon matrix is ​​5W / (mk)-20W / (mk). In one embodiment, the graphite matrix satisfies at least one of the following conditions:

[0006] (1) The expansion coefficient of the graphite matrix is ​​2x 10VC-3 xlO- 6 / °C;

[0007] (2) The porosity of the graphite matrix is ​​greater than 6%;

[0008] (3) The thermal conductivity of the graphite matrix is ​​30W / (mk)-100W / (mk). By regulating the expansion coefficient and thermal conductivity of the carbon matrix and the graphite matrix, the heating effect and overall stability of the cooking vessel can be further improved; by regulating the porosity of the carbon matrix and the graphite matrix, the organic carbonized material can be promoted to embed into the carbon matrix and the graphite matrix, thereby enhancing the bonding force and improving the interface stability. In one embodiment, the expansion coefficient of the organic carbonized layer is 3×10- 6 / °C-4X W 6 The carbonized organic layer has a specific thermal expansion coefficient, which can result in a relatively gentle gradient in the thermal expansion coefficients between the carbon matrix, the carbonized organic layer, and the graphite matrix. This further improves the overall stability of the cooking vessel and reduces the risk of cracking. In one embodiment, a portion of the carbonized organic material in the carbonized organic layer is embedded within the carbon matrix and the graphite matrix. In this cooking vessel structure, the carbonized organic material forms an "anchor" structure, significantly increasing the bonding strength between the carbon matrix and the graphite matrix, thereby further reducing the risk of thermal cracking in the cooking vessel. In one embodiment, the graphite matrix is ​​at least one centrosymmetric or axisymmetric graphite block. In one embodiment, the graphite matrix is ​​a single graphite block, with the central axis of the graphite matrix coinciding with that of the carbon matrix. Alternatively, the graphite matrix is ​​a plurality of graphite blocks, which are centrosymmetric or axisymmetrically distributed, with the central axis of the graphite blocks coinciding with that of the carbon matrix. By designing the shape and distribution of the graphite matrix, the heated material can be heated evenly, thereby improving the heating effect. A method for preparing the aforementioned cooking vessel includes the following steps: mixing carbon-based powder, mineral powder, and a first organic binder and pressing and molding to obtain a first green body; bonding the first green body to the graphite matrix using a second organic binder to obtain a second green body; and sintering the second green body at 500°C-100°C to obtain the cooking vessel. In the preparation method described herein, the second green body, produced by integral molding, is subjected to high-temperature sintering at 500-1000°C. This, on the one hand, converts the carbon-based powder in the first green body into an amorphous carbon material, which improves the hardness and heat storage efficiency of the heatable component. On the other hand, the liquid in the second organic binder evaporates and gasifies, and the residual organic matter carbonizes and partially embeds within the carbon and graphite matrices, forming a carbonized organic layer that creates an "anchor" structure. This significantly increases the bonding strength between the carbon and graphite matrices, improves interfacial stability, and further reduces the risk of thermal cracking in cooking utensils. In one embodiment, the carbon-based powder meets at least one of the following conditions:

[0009] (1) The mass fraction of the carbon-based powder in the first green body is 50%-80%;

[0010] (2) The particle size of the carbon-based powder is 100 mesh to 1000 mesh;

[0011] (3) The carbon-based powder is selected from at least one of bamboo charcoal powder, wood charcoal powder, binchotan charcoal powder, graphite powder, or carbon fiber powder. In one embodiment, the mineral powder satisfies at least one of the following conditions:

[0012] (1) The mass fraction of the mineral powder in the first green body is 10%-40%;

[0013] (2) The particle size of the mineral powder is 100-1000 mesh;

[0014] (3) The mineral powder is selected from at least one of medical stone powder and tourmaline powder. By regulating the content, particle size and type of the carbon-based powder and the mineral powder in the first blank, it is not only beneficial to ensure that the cooking vessel has good thermal conductivity, but also to ensure that the water quality in contact with the cooking vessel is maintained in a suitable pH range, so that it meets people's health requirements. In one embodiment, the first organic binder and the second organic binder are independently selected from at least one of epoxy resin glue and phenolic resin glue. The first organic binder can effectively bond the carbon-based powder and the mineral powder together, and form a carbon skeleton through sintering and carbonization, so that the amorphous carbon material and the mineral material are filled in the gaps of the carbon skeleton, thereby improving the strength of the carbon matrix. The second organic binder can bond the first blank to the graphite matrix and fill the pores between the first blank and the graphite matrix, thereby improving the bonding effect. In one embodiment, the step of bonding the first blank to the graphite matrix using the second organic binder meets at least one of the following conditions:

[0015] (1) The solid content of the second organic binder is 30%-60%;

[0016] (2) The graphite matrix is ​​selected from at least one of statically pressed graphite, molded graphite, or extruded graphite;

[0017] (3) The thickness of the graphite substrate is 1 / 3 to 2 / 3 of the thickness of the first green body;

[0018] (4) After the first green body is combined with the graphite matrix using the second organic binder, a pressurization treatment is further included. By regulating the preparation conditions in the step of combining the first green body with the graphite matrix using the second organic binder, the bonding strength and interface stability between the carbon matrix and the graphite matrix obtained after sintering are improved. In one embodiment, the sintering is carried out in a protective atmosphere, which is conducive to improving the carbonization effect and thus improving the thermal conductivity of the cooking vessel. Therefore, the cooking vessel of the present invention is used in cooking utensils to achieve a variety of heating methods such as electromagnetic heating, which not only improves the heating effect but also reduces the risk of cracking of the cooking vessel due to heat, thereby meeting the safety and health requirements of the cooking utensils. Description of the drawings In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings required for use in the embodiments or the prior art description will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. FIG1 is a schematic cross-sectional structural diagram of a cooking vessel according to one embodiment of the present invention; FIG2 is a schematic cross-sectional structural diagram of a cooking vessel according to another embodiment of the present invention; FIG3 is a schematic cross-sectional structural diagram of a cooking vessel according to another embodiment of the present invention; FIG4 is a schematic side cross-sectional structural diagram of a cooking vessel according to one embodiment of the present invention; FIG5 is a schematic cross-sectional structural diagram of the bottom of the cooking vessel shown in FIG4; FIG6 is a schematic side cross-sectional structural diagram of a cooking vessel according to another embodiment of the present invention; FIG7 is a schematic side cross-sectional structural diagram of a cooking vessel according to another embodiment of the present invention; FIG8 is a schematic cross-sectional structural diagram of the bottom of the cooking vessel shown in FIG7; FIG9 is a schematic cross-sectional structural diagram of the bottom of a cooking vessel according to another embodiment of the present invention; FIG10 is a schematic cross-sectional structural diagram of the bottom of a cooking vessel according to another embodiment of the present invention; FIG11 is a schematic side cross-sectional structural diagram of a cooking vessel according to another embodiment of the present invention; FIG12 is a schematic cross-sectional structural diagram of the bottom of the cooking vessel shown in FIG11; and FIG13 is a schematic side cross-sectional structural diagram of a cooking vessel according to another embodiment of the present invention. 10, cooking vessel; 101, carbon substrate; 102, carbonized organic layer; 103, graphite substrate; 104, glass sidewall. DETAILED DESCRIPTION OF THE INVENTION To facilitate understanding of the present invention, the present invention will be described in more detail below. However, it should be understood that the present invention can be implemented in many different forms and is not limited to the embodiments or examples described herein. Rather, these embodiments and examples are provided to provide a more thorough and comprehensive understanding of the present disclosure.Unless otherwise defined, all technical and scientific terms used herein have the same meanings as commonly understood by those skilled in the art to which the present invention pertains. The terms used in the present specification are intended solely for the purpose of describing specific embodiments or examples and are not intended to limit the present invention. Referring to FIG1 , a cooking vessel provided by the present invention is provided for use as a cooking appliance. The cooking vessel comprises a cooking container having a cooking cavity. The cooking container includes a bottom wall and side walls, which together form the cooking cavity. A carbon matrix 101 constitutes the bottom wall, or the bottom wall and at least a portion of the side walls. The carbon matrix 101 comprises a carbonaceous skeleton and amorphous carbon material and mineral material filling the interstices within the carbonaceous skeleton. A graphite matrix 103 is disposed on a portion of the surface or interior of the carbon matrix 101, and an organic carbonized layer 102 is disposed between the carbon matrix 101 and the graphite matrix 103. It should be noted that when the graphite matrix 103 is disposed inside the carbon matrix 101, it can be understood that the volume of the carbon matrix 101 must be greater than the volume of the graphite matrix 103. Since the graphite substrate 103 is disposed on a portion of the surface or interior of the carbon substrate 101, in actual application scenarios of cooking vessels, within a preset electromagnetic heating area, the thermal conductivity area of ​​the carbon substrate 101 mapped to the electromagnetic heating device is necessarily larger than the thermal conductivity area of ​​the graphite substrate 103 mapped to the electromagnetic heating device. Specifically, as shown in FIG1 , the thermal conductivity area of ​​the graphite substrate 103 is Si, and the thermal conductivity area of ​​the carbon substrate 101 is S2. Furthermore, the cooking vessel of the present invention has a unique structure. On the one hand, it can implement various heating methods such as electromagnetic heating. On the other hand, during the heating process, since the thermal conductivity of the graphite substrate 103 is higher than that of the carbon substrate 101, and the thermal conductivity area of ​​the carbon substrate 101 is larger than that of the graphite substrate 103, a temperature difference between hot and cold is formed on the heating surface, thereby achieving effective high and low temperature heating, accelerating heat convection and tumbling of the heated material, and thereby improving the heating effect. Furthermore, because the expansion coefficient of the carbon substrate 101 is greater than that of the carbonized organic layer 102, and the expansion coefficient of the carbonized organic layer 102 is greater than that of the graphite substrate 103, a gradient of thermal expansion coefficients is formed between the carbon substrate 101, the carbonized organic layer 102, and the graphite substrate 103. This provides a transitional effect, allowing for controllable overall stress during heating and reducing the risk of thermal cracking in the cooking vessel. Furthermore, the cooking vessel also possesses the advantages of amorphous carbon, such as high hardness, resistance to blackening, and excellent heat storage, which improves cooking performance.In one embodiment, as shown in FIG1 , a groove is formed on the surface of the carbon substrate 101, and the graphite substrate 103 is positioned within the groove. Alternatively, as shown in FIG2 , a cavity is formed within the interior of the carbon substrate 101, and the graphite substrate 103 is positioned within the cavity. Embedding the graphite substrate 103 within the carbon substrate 101 not only improves thermal conductivity but also reduces the exposed surface area of ​​the graphite, thereby improving issues such as blackening of the graphite surface. It should be noted that the carbonized organic layer 102 contacts at least one surface of the graphite substrate 103. Taking the structure shown in FIG2 as an example, the carbonized organic layer 102 may contact three surfaces of the graphite substrate 103, only one surface of the graphite substrate 103, or all four surfaces of the graphite substrate 103. This is not a limitation of the present invention. Preferably, the depth of the groove or cavity is no greater than two-thirds of the thickness of the carbon substrate 101. This not only improves the electromagnetic heating effect but also maintains a high strength of the surface carbon substrate 101, preventing defects such as cracks during heating. It should be noted that the depth of the groove or cavity refers to the maximum distance between the groove or cavity and the outer surface of the carbon substrate. In one embodiment, the carbon substrate 101 satisfies at least one of the following conditions:

[0019] (1) The expansion coefficient of the carbon matrix 101 is 4 ≤ 10-6 / . (:-6 ≤ 10-6 / .0

[0020] (2) The porosity of the carbon matrix 101 is greater than 6%;

[0021] (3) The thermal conductivity of the carbon substrate 101 is 5W / (mk)-20W / (mk). In one embodiment, the graphite substrate 103 satisfies at least one of the following conditions:

[0022] (1) The thermal expansion coefficient of the graphite substrate 103 is 2 x 10-6 / 0 (2-3 x 10-6 / G

[0023] (2) The porosity of the graphite substrate 103 is greater than 6%;

[0024] (3) The thermal conductivity of the graphite matrix 103 is 30W / (nrk)-100W / (m·k). By regulating the porosity of the carbon matrix 101 and the graphite matrix 103, it is beneficial to promote the embedding of the organic carbonized material into the carbon matrix 101 and the graphite matrix 103, enhance the bonding force, and improve the interface stability. By regulating the expansion coefficient and thermal conductivity of the carbon matrix 101 and the graphite matrix 103, it is beneficial to further improve the heating effect and overall stability of the cooking vessel. In one embodiment, the expansion coefficient of the organic carbonized layer 102 is 3 x 10-6 / 0C-4 x 10-6 / p, so that the gradient change rate of the thermal expansion coefficient between the carbon matrix 101, the organic carbonized layer 102, and the graphite matrix 103 is relatively slow, which is beneficial to further improve the overall stability of the cooking vessel and reduce the risk of cracking. In one embodiment, as shown in FIG3 , a portion of the organic carbonized material in the organic carbonized layer 102 is embedded within the carbon matrix 101 and the graphite matrix 103, forming an "anchor" structure. This significantly increases the bonding strength between the carbon matrix 101 and the graphite matrix 103, thereby further reducing the risk of thermal cracking of the cooking vessel. In one embodiment, the embedding depth of the portion of the organic carbonized material is preferably 10 μm to 200 μm, which further enhances the bonding strength between the carbon matrix 101 and the graphite matrix 103. In one embodiment, the graphite substrate 103 is at least one centrosymmetric or axisymmetric graphite block. Specifically, the graphite substrate 103 is a single graphite block, and the central axis of the graphite substrate 103 coincides with the central axis of the carbon substrate 101. Alternatively, the graphite substrate 103 is a plurality of graphite blocks, and the plurality of graphite blocks are distributed centrosymmetrically or axisymmetrically, and the plurality of graphite blocks coincide with the central axis of the carbon substrate 101. The shapes of the graphite blocks include, but are not limited to, circular, annular, sectoral, rectangular, and other symmetrical shapes, which can ensure uniform heating of the heated material and improve the heating effect. When the bottom wall and side walls of the cooking vessel are entirely directly formed by the carbon substrate 101, the cooking vessel has an integrated structure and can be used in the inner pot of an electric rice cooker, the inner pot of an electric stew pot, a soup pot, and the like.Specifically, in one embodiment, referring to the schematic side cross-sectional structure diagram of the cooking vessel 10 shown in FIG4 , a disc-shaped graphite substrate 103 is disposed at the bottom of the cooking vessel 10. The specific bottom cross-sectional structure is shown in FIG5 . In an electromagnetic heating environment or other heating environment, the graphite substrate 103 absorbs or generates heat, which is then longitudinally transferred to corresponding portions of the carbon substrate 101 perpendicular to the surface, creating a hot-cold temperature difference on the inner surface. During the heating of food or water, heat is transferred from higher to lower locations, generating bubble transfer as shown in FIG4 . This generates 180- to 360-degree water tumbling at the edges of the corresponding regions of the graphite substrate 103, accelerating heat convection and tumbling of the cooked food, thereby improving the cooking effect. The invention can be applied to products such as rice cookers, electric stew pots, and soup pots. In another embodiment, referring to the side cross-sectional view of the cooking vessel 10 shown in FIG6 , the graphite substrate 103 can also be disposed on both the bottom and sides of the cooking vessel 10, which helps improve overall thermal conductivity and thermal uniformity. This can be applied to products such as rice cookers, electric stew pots, and soup pots. Therefore, the graphite substrate 103 is not limited to being disposed on the bottom of the cooking vessel 10; it can also be disposed on the side walls of the cooking vessel 10, with one or more substrates. This ensures more uniform heating and higher heating efficiency in the cooking vessel 10, and the present invention is not limited thereto. In another embodiment, referring to the cross-sectional view of the cooking vessel 10 at different angles shown in FIG7 and FIG8 , the graphite substrate 103 comprises a plurality of circular graphite blocks arranged in a symmetrical array, located at the bottom of the cooking vessel 10. In an electromagnetic heating environment or other heating environment, the graphite substrate 103 absorbs heat or generates more heat, and this heat rapidly propagates longitudinally to the surface of the carbon substrate 101, forming multiple hot and cold zones on the surface of the carbon substrate 101. During cooking, these zones experience multiple boiling points, creating a temperature difference with the cold zones. This allows the cooking water, soup, and food to flow and boil, improving the cooking effect. This method can be used in products such as rice cookers, electric stew pots, and soup pots. In another embodiment, as shown in FIG9 , the graphite substrate 103 comprises two circular graphite blocks nested within the bottom of the cooking vessel 10. In another embodiment, as shown in FIG10 , the graphite substrate 103 comprises multiple equally spaced, symmetrically distributed trapezoidal or fan-shaped graphite blocks, located at the bottom of the cooking vessel 10. In another embodiment, referring to the schematic cross-sectional structural diagrams of the cooking vessel 10 at different angles shown in FIG. 11 and FIG. 12 , the graphite substrate 103 is in a curved ring shape and is distributed on the hemispherical bottom of the cooking vessel 10 .It should be noted that the cooking vessel 10 is not limited to electromagnetic heating. Products such as soup pots can also be adapted for other heating methods, such as open flames, and this is not a limitation of the present invention. When the carbon matrix 101 serves only as the bottom wall of the cooking vessel 10, other materials can be used as the side walls of the cooking vessel 10 and assembled with the carbon matrix 101 to form the cooking vessel 10, such as an electric cup or health pot. Specifically, in one embodiment, referring to the schematic side cross-sectional structure of the cooking vessel 10 shown in FIG13 , the carbon matrix 101 serves as the bottom wall and is assembled with glass side walls to form the cooking vessel 10. The graphite matrix 103 in the bottom wall is a circular graphite block. The bottom cross-section of the cooking vessel 10 is similar to that in FIG12 , and the present invention will not repeat the diagrams. This cooking vessel 10 can be heated by electromagnetic or resistive heating, generating heat convection to enhance cooking performance. It can be applied to products such as electric cups and health pots. It should be noted that after the exposed surface of the graphite substrate 103 is coated, it can serve as either the outer or inner surface of the cooking vessel, and the present invention is not limited thereto. The cooking vessel 10 of the present invention can be used in a cooking vessel to implement various heating methods, such as electromagnetic heating. This not only improves heating efficiency but also reduces the risk of cracking caused by heat, thereby meeting various safety and health requirements for cooking vessels. The present invention provides a method for preparing the aforementioned cooking vessel 10, comprising the following steps:

[0025] 51. Mix the carbon-based powder, the mineral powder and the first organic binder and press-form them to obtain a first green body;

[0026] 52, using a second organic binder to combine the first green body and the graphite substrate 103 to obtain a second green body;

[0027] S3. Sinter the second green body at 500°C-1000°C to obtain the cooking vessel 10. In step S1, the first green body of various shapes and sizes can be produced by press molding using a 1000-2000 ton press. Preferably, a recess for accommodating the graphite substrate 103 is reserved on the first green body to facilitate one-step molding. The carbon-based powder not only has good thermal conductivity but also good adsorption properties, enabling water purification. Furthermore, the carbon-based powder has excellent stability and hardness, making the resulting cooking vessel 10 less susceptible to rust or deformation. In one embodiment, the carbon-based powder meets at least one of the following conditions:

[0028] (1) The mass fraction of the carbon-based powder in the first green body is 50%-80%;

[0029] (2) The particle size of the carbon-based powder is 100-1000 mesh; (3) The carbon-based powder is selected from at least one of bamboo charcoal powder, wood charcoal powder, binchotan charcoal powder, graphite powder, or carbon fiber powder. The pH value of the bamboo charcoal powder, wood charcoal powder, binchotan charcoal powder, graphite powder, and carbon fiber powder is between 8.5 and 9.5, which is alkaline. During contact with water, the pH value of the water can be adjusted to obtain weakly alkaline water, which meets people's health requirements.

[0030] (1) The mass fraction of the mineral powder in the first green body is 10%-40%;

[0031] (2) The particle size of the mineral powder is 100-1000 mesh;

[0032] (3) The mineral powder is selected from at least one of medical stone powder and tourmaline powder. Medical stone powder and tourmaline powder release alkaline metal oxides such as sodium oxide, potassium oxide, and aluminum oxide, thereby adjusting the pH value of water to obtain weakly alkaline water. They also provide minerals beneficial to the human body, which helps enhance the competitiveness of the product. By regulating the content of carbon-based powder in the first body to be relatively high and the content of mineral powder to be relatively low, it is not only beneficial to ensure that the cooking vessel 10 has good thermal conductivity, but also to ensure that the water quality is maintained within a suitable pH range. In one embodiment, the first organic binder is selected from at least one of epoxy resin glue and phenolic resin glue. Since the carbon-based powder and mineral powder have micropores on their surfaces, during the mixing and pressing steps, the viscosity of the first organic binder is controlled (approximately 200 to 500 Pa·s) to allow the binder to penetrate some of the micropores, thereby effectively bonding the carbon-based powder and the mineral powder together. Subsequently, during sintering, the first organic binder is carbonized at a certain temperature to form a carbonaceous skeleton, allowing the amorphous carbon material and the mineral material to fill the gaps in the carbonaceous skeleton, thereby enhancing the strength of the carbon matrix 101. It should be noted that the first organic binder can be a conventional existing product or can be prepared independently, and the present invention is not limited thereto. Taking phenolic resin as an example, the particle size of the phenolic powder particles is preferably 0.1 μm / pm. The phenolic powder particles can be prepared into a phenolic resin glue using a diluent such as acetone or methanol. The solid content of the phenolic resin glue is preferably 30%-60%. In step S2, the graphite substrate 103 can be directly bonded to the surface of the first green body using a second organic binder. Preferably, the second organic binder is applied to a pre-reserved groove in the first green body, and the graphite substrate 103 is placed in the groove to bond the first green body to the graphite substrate 103. Alternatively, after the graphite substrate 103 is placed in the groove, the first green body is covered on the surface of the graphite substrate 103, and a secondary press is performed using a 1000-2000 ton press to encapsulate the graphite substrate 103 within the interior of the first green body. The present invention is not limited to this. In one embodiment, the step of bonding the first green body to the graphite substrate 103 using the second organic binder satisfies at least one of the following conditions:

[0033] (1) The solid content of the second organic binder is 30%-60%;

[0034] (2) The graphite substrate is selected from at least one of statically pressed graphite, molded graphite or extruded graphite;

[0035] (3) The thickness of the graphite matrix is ​​1 / 3-2 / 3 of the thickness of the first green body; (4) After the first green body and the graphite matrix are bonded using a second organic binder, a pressurization treatment is further included. Since the surfaces of the first green body and the graphite matrix 103 have certain pores, the pressurization treatment can promote the penetration of the second organic binder into the first green body and the graphite matrix 103, which is beneficial to the carbonization of organic matter with an "anchor" structure during the subsequent sintering process, thereby improving the bonding strength and interface stability. In one embodiment, the second organic binder is selected from at least one of epoxy resin glue and phenolic resin glue. In step S3, sintering at a high temperature of 500°C to 1000°C converts the carbon-based powder in the first green body into an amorphous carbon material, which improves the hardness and heat storage performance of the cooking vessel 10. Furthermore, the liquid in the second organic binder evaporates and gasifies, and the remaining organic matter carbonizes and partially embeds within the carbon matrix 101 and the graphite matrix 103, forming a carbonized organic layer that forms an "anchor" structure. This significantly increases the bonding strength between the carbon matrix 101 and the graphite matrix 103, improves interfacial stability, and further reduces the risk of thermal cracking in the cooking vessel 10. In one embodiment, the sintering is performed in a protective atmosphere selected from an inert gas, optionally nitrogen and / or chlorine, which improves the carbonization effect and, in turn, the thermal conductivity of the resulting cooking vessel 10. In one embodiment, after sintering, the cooking vessel 10 is further polished. Specifically, the polishing process involves polishing the surface of the cooking vessel 10 using a scouring pad, sandpaper, or a polishing material such as silicon carbide. In one embodiment, a silicon carbide coating, a pyrolytic carbon coating, or an inorganic silicon oxide coating is applied to the exposed surface of the graphite substrate 103 to prevent the graphite from discoloring. The cooking vessel and its preparation method will be further described below using the following specific examples. Raw materials: Phenolic resin (3% addition, 50% solid content); epoxy resin (5% addition, 45% solid content); bamboo charcoal powder (800 mesh); wood charcoal powder (900 mesh); binchotan charcoal powder (1000 mesh); graphite powder (600 mesh); medical stone powder (800 mesh); tourmaline powder (800 mesh); isostatically pressed graphite (expansion coefficient of 2x 10-6 / 1, thermal conductivity of 90W / (mk), porosity of 8%); molded graphite (expansion coefficient of 2.5x10-6 / .(?), thermal conductivity of 50W / (mk), porosity of 15%); extruded graphite (expansion coefficient of 3x10-6 / .(?, thermal conductivity of 30W / (mk), porosity of 25%).Examples 1-4 were all prepared according to the cooking vessel structures shown in Figures 4 and 5. In Example 1, 200g of bamboo charcoal powder, 200g of wood charcoal powder, 200g of binchotan charcoal powder, 150g of medical stone powder, 150g of tourmaline powder, and 100g of epoxy resin were uniformly mixed to form a slurry. The slurry was then compacted using a 200MPa molding press and a mold to produce a first green body having a groove. The first green body had a thickness of 6mm and a groove depth of 2mm. Epoxy resin was evenly applied to the groove, and isostatic graphite was placed in the groove and pressurized using a 500MPa isostatic press to produce a second green body. The second green body was sintered at 1000°C in a nitrogen atmosphere to produce the cooking vessel. Testing showed that the expansion coefficient of the carbon matrix in the cooking vessel was 4×10-. 6 / °C, thermal conductivity of 20W / (mk) (according to GB / T7320-2018 thermal expansion coefficient test), porosity of 2%; expansion coefficient of the organic carbonized layer is 3X10-6 / . (?, the embedding depth of the organic carbonized material is 200 μm. Example 2

[0036] 300g of bamboo charcoal powder, 150g of wood charcoal powder, 150g of binchotan charcoal powder, 200g of medical stone powder, 150g of tourmaline powder, and 50g of phenolic resin were uniformly mixed to form a slurry. The slurry was then pressed into shape using a press and a mold to produce a first green body with a groove. The first green body had a thickness of 6mm and a groove depth of 3mm. Epoxy resin was evenly applied to the groove, and static graphite was placed and pressurized to produce a second green body. The second green body was sintered at 900°C in a nitrogen atmosphere to produce a cooking vessel. Testing showed that the carbon matrix in the cooking vessel had an expansion coefficient of 5x10-6 / , a thermal conductivity of 15W / (mK), and a porosity of 3.5%. The expansion coefficient of the organic carbonized layer was 3.3x10-6 / , and the embedding depth of the organic carbonized material was 100 μm. Example 3: 300g of charcoal powder, 300g of binchotan charcoal powder, 300g of tourmaline powder, and 100g of epoxy resin were uniformly mixed to form a slurry. The slurry was then pressed into shape using a press and a mold to produce a first green body having a groove. The thickness of the first green body was 6mm, and the groove was 3.5mm deep. Epoxy resin was evenly applied to the groove, and static graphite was placed and pressurized to produce a second green body. The second green body was sintered at 800°C in a nitrogen atmosphere to produce a cooking vessel. Testing showed that the thermal expansion coefficient of the carbon matrix in the cooking vessel was 5.5μm / s. (?, thermal conductivity of 10 W / (mk), porosity of 4.6%; expansion coefficient of the organic carbonized layer of 3.7 x 10-6 / .., embedding depth of the organic carbonized material of 130 μm. Example 4: 600 g of binchotan charcoal powder, 100 g of medical stone powder, 200 g of tourmaline powder, and 100 g of epoxy resin were uniformly mixed to form a slurry. The slurry was pressed into shape using a press and a mold to obtain a first green body having a groove. The first green body had a thickness of 6 mm and a groove depth of 4 mm. Epoxy resin was evenly applied to the groove, and static graphite was placed and pressurized to obtain a second green body. The second green body was sintered at 500°C in a nitrogen environment to obtain a cooking vessel. Testing showed that the expansion coefficient of the carbon matrix in the cooking vessel was 6 x 10-6 / .., and the thermal conductivity was 5 W / (mk). (Tested in accordance with GB / T7320-2018 thermal expansion coefficient), the porosity is 6%; the expansion coefficient of the organic carbonized layer is 4×10-6 / . (?), and the embedding depth of the organic carbonized material is 200 μm. Comparative Example 1: The difference between Comparative Example 1 and Example 1 is that the sintering temperature is 1400°C. The expansion coefficient of the carbon substrate in the cooking vessel produced in this comparative example is 1.8×10-.6 / °C, the expansion coefficient of the carbonized layer of organic matter is

[0037] 3.1 x 10". Comparative Example 2: The difference between Comparative Example 2 and Example 1 lies in that an epoxy resin with an 80% solid content is evenly coated within the groove. The expansion coefficient of the carbonized layer of organic matter in the cooking vessel produced in this comparative example is 2 x 10-6 / . Comparative Example 3: The difference between Comparative Example 3 and Example 1 lies in that graphite is directly used as the blank and sintered to produce the cooking vessel. The cooking vessels produced in Examples 1-4 and Comparative Examples 1-3 were directly used as cookware for performance testing. The results are shown in Table 1. Test Method: The cooking vessel was placed in a constant temperature oven at 420°C with a temperature difference of ±5°C. After holding the temperature for 30 minutes, it was removed from the oven. The rim of the cooking vessel was placed at an angle of approximately 45 degrees to the water surface. The vessel was immersed in water at the fastest speed and soaked for 10 minutes. The cooking vessel was removed and wiped dry with a cloth. The above steps constituted one cycle. The cycle was repeated three times to test the cooking vessel's resistance to cold and heat shock. Table 1 As shown in Table 1, the cooking utensils produced in Examples 1-4 achieve heat conduction under electromagnetic heating conditions and do not crack under extreme temperatures of 420°C, demonstrating high safety. Compared to Examples 1-4, Comparative Examples 1-2 exhibited microcracks and cracking, while Comparative Example 3 exhibited blackening, making it unsuitable for use as cooking utensils in direct contact with food. The technical features of the above-described embodiments can be combined arbitrarily. To simplify the description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as these combinations do not conflict, they should be considered within the scope of this specification. The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that variations and modifications are possible within the scope of the present invention, as long as they do not depart from the spirit of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

Claims 1. A cooking vessel, used for cooking utensils, the cooking vessel comprising a cooking container provided with a cooking cavity, characterized in that: The cooking container comprises a bottom wall and a side wall, wherein the bottom wall and the side wall together form a cooking cavity, wherein the carbon matrix (101) constitutes the bottom wall, or the carbon matrix (101) constitutes the bottom wall and at least part of the side wall, the carbon matrix (101) comprises a carbon skeleton and an amorphous carbon material and a mineral material filled in the gaps of the carbon skeleton, a graphite matrix (103) is arranged on a part of the surface or inside of the carbon matrix (101), and an organic carbonized layer (102) is arranged between the carbon matrix and the graphite matrix; the cooking container also satisfies the following conditions at the same time: (1) The thermal conductivity of the carbon matrix (101) is smaller than the thermal conductivity of the graphite matrix (103); (2) The expansion coefficient of the carbon matrix (101) is greater than the expansion coefficient of the organic carbonized layer (102), and the expansion coefficient of the organic carbonized layer (102) is greater than the expansion coefficient of the graphite matrix (103).

2. The cooking vessel according to claim 1, characterized in that: A groove is provided on the surface of the carbon matrix (101), and the graphite matrix (103) is located in the groove; or a cavity is provided inside the carbon matrix (101), and the graphite matrix (103) is located in the cavity.

3. The cooking vessel according to claim 2, characterized in that: The depth of the groove or the cavity is no more than 2 / 3 of the thickness of the carbon matrix.

4. The cooking vessel according to any one of claims 1 to 3, characterized in that: The carbon matrix (101) satisfies at least one of the following conditions: (1) The expansion coefficient of the carbon matrix is ​​4×10- 6 / °C-6X 10- 6 / °C ; (2) The porosity of the carbon matrix is ​​greater than 6%; (3) The thermal conductivity of the carbon matrix is ​​5W / (mk)-20W / (mk) 5. The cooking vessel according to any one of claims 1 to 4, characterized in that: The graphite substrate (103) (1) The expansion coefficient of the graphite matrix is ​​2 x 10VC-3 x 10- 6 / °C; (2) The porosity of the graphite matrix is ​​greater than 6%; (3) The thermal conductivity of the graphite matrix is ​​30W / (mk)-100W / (mk) 6. The cooking vessel according to any one of claims 1 to 5, characterized in that The expansion coefficient of the organic carbonized layer (102) is 3×10- 6 / °C-4X W 6 / °CO 7. The cooking vessel according to any one of claims 1 to 6, characterized in that Part of the organic carbonized material in the organic carbonized layer (102) is embedded in the carbon matrix (101) and the graphite matrix (103).

8. The cooking vessel according to any one of claims 1 to 7, characterized in that: The graphite substrate (103) It is at least one centrosymmetric or axisymmetric graphite block.

9. The cooking vessel according to any one of claims 1 to 8, characterized in that: The graphite matrix (103) is a graphite block, and the central axes of the graphite matrix and the carbon matrix coincide with each other; or, the graphite matrix is ​​a plurality of graphite blocks, the plurality of graphite blocks are centrally symmetrically or axially symmetrically distributed, and the central axes of the plurality of graphite blocks and the carbon matrix coincide with each other.

10. A method for preparing a cooking vessel according to any one of claims 1 to 9, characterized in that: The method comprises the following steps: mixing carbon-based powder, mineral powder and a first organic binder and pressing them into a shape to obtain a first green body; combining the first green body with a graphite matrix using a second organic binder to obtain a second green body; and sintering the second green body at 500° C.-1000° C. to obtain the cooking vessel.

11. The method for preparing a cooking vessel according to claim 10, characterized in that: The carbon-based powder satisfies at least one of the following conditions: (1) The mass fraction of the carbon-based powder in the first green body is 50%-80%; (2) The particle size of the carbon-based powder is 100 mesh to 1000 mesh; (3) The carbon-based powder is selected from at least one of bamboo charcoal powder, wood charcoal powder, binchotan powder, graphite powder or carbon fiber powder.

12. The method for preparing a cooking vessel according to claim 10 or 11, characterized in that: The mineral powder satisfies at least one of the following conditions: (1) The mass fraction of the mineral powder in the first green body is 10%-40%; (2) The particle size of the mineral powder is 100-1000 mesh; (3) The mineral powder is selected from at least one of medical stone powder and tourmaline powder.

13. The method for preparing a cooking vessel according to any one of claims 10 to 12, characterized in that: The first organic binder and the second organic binder are independently selected from at least one of epoxy resin glue and phenolic resin glue.

14. The method for preparing a cooking vessel according to any one of claims 10 to 13, characterized in that: The step of combining the first green body with the graphite substrate using a second organic binder satisfies at least one of the following conditions: (1) The solid content of the second organic binder is 30%-60%; (2) The graphite matrix is ​​selected from at least one of statically pressed graphite, molded graphite or extruded graphite; (3) The thickness of the graphite substrate is 1 / 3-2 / 3 of the thickness of the first green body; (4) After the first green body is combined with the graphite substrate by using a second organic binder, a pressurization treatment is also included.

15. The method for preparing a cooking vessel according to any one of claims 10 to 14, characterized in that: The sintering is carried out in a protective atmosphere.

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