Cooking containers and cooking equipment

Abstract

The present invention provides a cooking container and cooking equipment. The cooking container comprises a ceramic substrate; a heating layer disposed on at least a portion of the inner surface of the ceramic substrate. The heating layer has a sheet resistance of 1mΩ to 20mΩ and comprises a metallic magnetic material having a melting point greater than 1000 degrees Celsius and a relative magnetic permeability less than 10. This cooking container achieves high heating efficiency and uniformity while also exhibiting excellent stability and reliability. The layers also exhibit strong bonding, providing a superior user experience.

Description

Technical Field

[0001] The present invention relates to the technical field of cooking equipment, and in particular to a cooking container and cooking equipment. Background Art

[0002] Ceramic materials, due to their numerous advantages, have played a significant role in everyday cooking. The Chinese have a millennium-long tradition of using ceramic utensils, whose environmental friendliness, safety, and sanitation are unmatched by today's commonly used metal cookware. However, due to their poor heat transfer properties, ceramic utensils often suffer from low heating efficiency, poor cooking results, and difficulty in temperature control.

[0003] Therefore, the relevant technology of ceramic cookware still needs to be improved. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems in the related art to a certain extent. To this end, one object of the present invention is to provide a cooking container with high heating efficiency, good heating uniformity, good stability and long service life.

[0005] In one aspect, the present invention provides a cooking container. According to an embodiment of the present invention, the cooking container includes: a ceramic substrate; and a heating layer disposed on at least a portion of the inner surface of the ceramic substrate. The heating layer has a sheet resistance of 1 mΩ to 20 mΩ and comprises a metallic magnetic material having a melting point greater than 1000 degrees Celsius and a relative magnetic permeability less than 10. In the cooking container, the relative magnetic permeability of the metal magnetic material in the heating layer is less than 10. In an alternating magnetic field environment, the metal magnetic material is used to generate eddy currents and thus generate heat. The present invention limits the square resistance of the heating layer to a range of 1mΩ to 20mΩ, which can achieve a higher induction resistance and thus a higher heating power. The melting point of the metal magnetic material in the above-mentioned heating layer is greater than 1000 degrees Celsius. The melting point of the metal magnetic material is relatively high, so the heating layer is not easy to melt and is not easily damaged in the subsequent sintering step, and is relatively stable, thereby making the square resistance of the heating layer more stable, which is beneficial to limiting the square resistance of the heating layer to a range of 1mΩ to 20mΩ, which is beneficial to reducing the risk of large fluctuations in the square resistance value of the heating layer during the preparation process of the cooking container, improving the controllability of the heating performance of the heating layer, and further improving the heating efficiency and heating uniformity of the heating layer, thereby extending the service life of the cooking container, reducing production costs, and at the same time being able to achieve magnetic high-power heating. However, the heating layer formed by low-melting-point materials such as silver and aluminum in the prior art is easily damaged and unstable in the subsequent high-temperature sintering step, resulting in unstable square resistance and poor heating performance of the heating layer, which increases the production cost of the cooking appliance. The present invention solves this technical problem.

[0006] Optionally, the relative magnetic permeability of the metallic magnetic material is greater than 1 and less than 10.

[0007] Optionally, the cooking container further includes: a first glaze layer, the first glaze layer being arranged on at least a portion of the surface of the heating layer away from the ceramic substrate, and the sintering temperature of the first glaze layer being greater than 1000 degrees Celsius.

[0008] Optionally, the sintering temperature of the first glaze layer is 1100-1200 degrees Celsius.

[0009] Optionally, the content of the metal magnetic material in the heating layer is 60-90 wt %; and / or the difference between the expansion coefficient of the ceramic substrate and the expansion coefficient of the metal magnetic material is within the range of ±30%.

[0010] Optionally, at least one of the following conditions is met: the electrical conductivity of the metal magnetic material measured at 20 degrees Celsius is ≤7*10 -8 S / m; the expansion coefficient of the metal magnetic material measured at 100-300 degrees Celsius is 1*10 -6 ~3*10 -6 / ℃; the expansion coefficient of the ceramic substrate measured at 100-300 degrees Celsius is 0.5×10 -6 ~2×10 -6 / ℃.

[0011] Optionally, the sintering temperature of the heating layer is greater than 1000 degrees Celsius.

[0012] Optionally, the sintering temperature of the heating layer is 1300-1700 degrees Celsius.

[0013] Optionally, the metallic magnetic material is tungsten.

[0014] Optionally, the cooking container further includes: a second glaze layer, wherein the second glaze layer is disposed on at least a portion of the outer surface of the ceramic substrate.

[0015] Optionally, the sintering temperature of the second glaze layer is greater than 1000 degrees Celsius.

[0016] Optionally, at least one of the following conditions is met: the thickness of the first glaze layer and the second glaze layer is independently 100 μm to 500 μm; the expansion coefficient of the first glaze layer and the second glaze layer measured at 100-300 degrees Celsius is independently 0.5×10 -6 ~2×10 -6 / ℃; the materials of the first glaze layer and the second glaze layer each independently include at least one selected from aluminum oxide, silicon oxide, lithium oxide, titanium oxide, potassium oxide and sodium oxide.

[0017] Optionally, the second glaze layer and the first glaze layer are connected at the container opening of the cooking container, and the first glaze layer and the second glaze layer are connected in a smooth transition.

[0018] Optionally, the thickness of the heating layer is 10 μm to 50 μm; and / or at least a portion of the heating layer away from the center of the bottom wall of the cooking container has a trend of gradually decreasing thickness.

[0019] Optionally, the heating layer extends from the bottom wall to the side wall of the cooking container, and the average thickness of the heating layer at the side wall is less than the average thickness of the heating layer at the bottom wall.

[0020] Optionally, the thickness of the heating layer arranged on the upper part of the side wall of the cooking container is smaller than the thickness of the heating layer arranged on the lower part of the side wall of the cooking container, and the heating layer on the upper part of the side wall and the heating layer on the lower part of the side wall are smoothly transitioned and connected.

[0021] Optionally, the thickness of the connection between the heating layer at the upper portion of the side wall and the heating layer at the lower portion of the side wall changes gradually.

[0022] Optionally, the heating layer includes a transition connection layer and a metal layer, the metal layer includes a metallic magnetic material and a glass phase, the transition connection layer includes a glass phase, and the ceramic substrate is connected to the metal layer through the transition connection layer.

[0023] Optionally, the metallic magnetically sensitive material is embedded in the glass phase of the transition connecting layer; and / or the glass phase in the metallic layer and the glass phase in the transition connecting layer are connected to each other.

[0024] Optionally, the materials of the glass phase in the transition connecting layer and the glass phase in the metal layer are independently selected from at least one of aluminum oxide, silicon oxide, lithium oxide, titanium oxide, potassium oxide and sodium oxide.

[0025] Optionally, the ratio of the area of ​​the heating layer covering the surface of the ceramic substrate to the area of ​​the entire surface of the ceramic substrate close to the heating layer is 1 / 3 to 1.

[0026] Optionally, the thickness of the portion of the ceramic substrate in contact with the heating layer is 4 mm to 6.5 mm.

[0027] Optionally, the first glaze layer covers the surface of the heating layer away from the ceramic substrate and the inner surface of the ceramic substrate not covered by the heating layer.

[0028] Optionally, the second glaze layer covers the entire outer surface of the ceramic substrate.

[0029] Optionally, the cooking container also includes a third glaze layer, which is arranged on the inner surface of the ceramic substrate, and the heating layer is arranged on the surface of the third glaze layer away from the ceramic substrate, and the first glaze layer is arranged on the surface of the heating layer away from the ceramic substrate and the surface of the third glaze layer not covered by the heating layer.

[0030] In another aspect, the present invention provides a cooking device. According to an embodiment of the present invention, the cooking device includes the aforementioned cooking container. The cooking device has all the features and advantages of the aforementioned cooking container, which will not be described in detail here.

[0031] Optionally, the cooking device is at least one of an electric rice cooker, an electric pressure cooker, an electric stew pot and an electric frying pan. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic cross-sectional structural diagram of a cooking container according to an embodiment of the present invention.

[0033] Figure 2 FIG. 1 is a top view of a cooking container according to an embodiment of the present invention.

[0034] Figure 3 1 is a bottom view of a cooking container according to an embodiment of the present invention.

[0035] Figure 4 2 is a schematic cross-sectional view of a cooking container according to another embodiment of the present invention.

[0036] Figure 5 2 is a schematic cross-sectional view of a cooking container according to another embodiment of the present invention.

[0037] Figure 6 It is a schematic cross-sectional structural diagram of a cooking device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0038] The following embodiments of the present invention are described in detail. The embodiments described below are exemplary and are only used to explain the present invention, and are not to be construed as limiting the present invention. Where specific techniques or conditions are not specified in the embodiments, the techniques or conditions described in the literature in the art or in the product specifications shall be followed.

[0039] In one aspect of the present invention, a cooking container is provided. Figure 1 、 Figure 2 and Figure 3The cooking container includes a ceramic substrate 10 and a heating layer 30 disposed on at least a portion of the inner surface of the ceramic substrate 10. The heating layer 30 has a sheet resistance of 1 mΩ to 20 mΩ and comprises a metallic magnetic material having a melting point greater than 1000 degrees Celsius and a relative magnetic permeability less than 10. It should be noted that the inner surface of the ceramic substrate constitutes the cavity of the cooking container. In the cooking container, the relative magnetic permeability of the metal magnetic material in the heating layer is less than 10. In an alternating magnetic field environment, the metal magnetic material is used to generate eddy currents and thus generate heat. The present invention limits the square resistance of the heating layer to a range of 1mΩ to 20mΩ, which can achieve a higher induction resistance and thus a higher heating power. The melting point of the metal magnetic material in the above-mentioned heating layer is greater than 1000 degrees Celsius. The melting point of the metal magnetic material is relatively high, so the heating layer is not easy to melt and is not easily damaged in the subsequent sintering step, and is relatively stable, thereby making the square resistance of the heating layer more stable, which is beneficial to limiting the square resistance of the heating layer to a range of 1mΩ to 20mΩ, which is beneficial to reducing the risk of large fluctuations in the square resistance value of the heating layer during the preparation process of the cooking container, improving the controllability of the heating performance of the heating layer, and further improving the heating efficiency and heating uniformity of the heating layer, thereby extending the service life of the cooking container, reducing production costs, and at the same time being able to achieve magnetic high-power heating. However, the heating layer formed by low-melting-point materials such as silver and aluminum in the prior art is easily damaged and unstable in the subsequent high-temperature sintering step, resulting in unstable square resistance and poor heating performance of the heating layer, which increases the production cost of the cooking appliance. The present invention solves this technical problem.

[0040] In some embodiments, the relative magnetic permeability of the metal magnetic material is greater than 1 and less than 10. Thus, the relative magnetic permeability of the metal magnetic material is limited to the above range, further enabling the heating layer containing the above metal magnetic material to achieve higher heating power.

[0041] According to an embodiment of the present invention, the ceramic substrate may be spodumene ceramic. Specifically, spodumene ceramic refers to a ceramic with spodumene as the main crystal phase, i.e., a Li2O-Al2O3-4SiO2 system ceramic, which has a low linear expansion coefficient and good thermal stability. It does not produce cracks after a quenching test from 1000°C to cold water. Therefore, the cooking container has good heat resistance and stability, and a long service life. Specifically, the expansion coefficient of the ceramic substrate measured at 100-300 degrees Celsius can be 0.5×10 -6 / ℃~2×10 -6 / ℃(Specifically, 0.5×10 -6 / ℃、0.8×10 -6 / ℃、1×10 -6 / ℃、1.2×10 -6 / ℃、1.5×10 -6 / ℃、1.8×10 -6 / ℃、2×10 -6 / ℃, etc.). As a result, the ceramic substrate will be less deformed under hot and cold conditions, resulting in better performance.

[0042] According to the embodiments of the present invention, the specific shape and size of the ceramic substrate are not particularly limited and can be flexibly adjusted according to the use requirements. For example, it can be a frying pan, a round-bottomed frying pan, an electric rice cooker liner, an electric stew pot liner, etc. The size can be adjusted according to the amount of ingredients suitable for cooking. No further details are given here. In some specific embodiments, referring to Figure 1 The ceramic substrate 10 may include a bottom 11 and a sidewall 12 connected to the bottom and extending upward. The bottom 11 and the sidewall 12 together define a cooking space 13 for cooking ingredients. Specifically, the bottom 11 and the sidewall 12 may have a smooth transition (or an arc-shaped transition). In the direction away from the bottom 11, the circumference of the sidewall 12 may be the same (for example, the inner pot of an electric rice cooker or an electric stew pot), gradually increase (for example, a wok), gradually decrease, first remain unchanged and then decrease, or first increase and then decrease (for example, a ceramic stew pot), etc. In other words, the ceramic substrate may be of equal thickness from top to bottom or of unequal thickness. In the case of unequal thickness, the ceramic substrate may gradually increase in thickness, gradually decrease in thickness, first be of equal thickness and then gradually decrease in thickness, or first increase in thickness and then decrease in thickness, etc., in the direction extending from the bottom to the sidewall (or from bottom to top).

[0043] According to embodiments of the present invention, the thickness of the ceramic substrate affects the performance of the cooking container. Specifically, under other conditions remaining the same (e.g., the material of the ceramic substrate remains unchanged, the distance between the cooking container and the magnetic field generator remains unchanged, and the working environment remains unchanged), the thicker the ceramic substrate, the lower the heating power of the heating layer. Furthermore, the temperature is more likely to concentrate during cooking, forming high temperature points and affecting the cooking effect. Furthermore, the thinner the ceramic substrate, the lower the strength of the cooking container. The inventors have verified that the thickness of the ceramic substrate at the point of contact with the heating layer is between 4 mm and 6.5 mm (specifically, 4 mm, 4.1 mm, 4.3 mm, 4.5 mm, 4.7 mm, 4.9 mm, 5 mm, 5.1 mm, 5.3 mm, 5.5 mm, 5.7 mm, 5.9 mm, 6.1 mm, 6.3 mm, 6.5 mm, etc.). Within this thickness range, both the strength of the cooking container and the high heating power can be achieved, resulting in a better performance.

[0044] It should be noted that the ceramic substrate may be provided with a heating layer only on a portion of the inner surface (see Figure 1 ), or a heating layer may be provided on all inner surfaces (see Figure 4), and in the cooking container, only the thickness of the position where the ceramic substrate contacts the heating layer needs to be within the range of 4mm to 6.5mm, and the thickness of the ceramic substrate that is not in contact with the heating layer can be flexibly adjusted according to actual needs. The proportion of the heating layer covering the inner surface of the ceramic substrate can be adjusted as needed. Specifically, the covering area of ​​the heating layer can be adjusted according to the magnetic field generating device used to excite the electromagnetic induction heating of the heating layer, so that the heating layer can effectively generate induced eddy currents and generate heat. In some specific embodiments, the ratio of the area of ​​the heating layer covering the inner surface of the ceramic substrate to the area of ​​the inner surface of the ceramic substrate is 1 / 3 to 1 (specifically 1 / 3, 1 / 2, 2 / 3, 1, etc.).

[0045] According to an embodiment of the present invention, the ceramic substrate can be formed by spinning or dry powder pressing. Specifically, the ceramic substrate can be formed by spinning or dry powder pressing, followed by surface drying. The composition, shape, and dimensions of the ceramic substrate are consistent with those described above and will not be further elaborated here.

[0046] According to an embodiment of the present invention, the content of the above-mentioned metal magnetic material in the above-mentioned heating layer is 60-90wt% (specifically 60wt%, 70wt%, 80wt%, 90wt%, etc.), and the balance is glass phase. Therefore, the content of the metal magnetic material in the heating layer is limited to the above-mentioned range, and the distribution of the metal magnetic material in the heating layer is further made more uniform, so that the heat generated by the metal magnetic material will not be concentrated in large quantities, thereby reducing the formation of hot spots in the heating layer and the ceramic substrate, reducing the risk of ceramic substrate cracking, and improving the service life of the ceramic substrate. At the same time, it also improves the bonding strength between the ceramic substrate and the heating layer.

[0047] According to an embodiment of the present invention, the difference between the expansion coefficient of the above-mentioned ceramic substrate and the expansion coefficient of the above-mentioned metal magnetic material is within the range of ±30%. Therefore, the expansion coefficient of the above-mentioned ceramic substrate is close to the expansion coefficient of the above-mentioned metal magnetic material. On the one hand, the risk of cracking of the ceramic substrate and the heating layer during the sintering process is reduced; on the other hand, the tightness between the interface between the ceramic substrate and the heating layer is improved, thereby reducing the interface thermal resistance between the ceramic substrate and the heating layer, improving the uniformity of heat transfer between the layers, and reducing the thermal stress generated by heat accumulation between the ceramic substrate and the heating layer in the subsequent heating process, thereby reducing the risk of cracking of the cooking container.

[0048] In some embodiments, the electrical conductivity of the metal magnetic material measured at 20 degrees Celsius is ≤7*10 -8 S / m, thereby further improving the heating efficiency of the heat generating layer.

[0049] In some embodiments, the expansion coefficient of the metal magnetic material measured at 100-300 degrees Celsius is 1*10 -6~3*10 -6 / ℃(Specifically, 1×10 -6 / ℃、1.3×10 -6 / ℃、1.5×10 -6 / ℃、1.8×10 -6 / ℃、2.0×10 -6 / ℃、2.5×10 -6 / ℃、3.0×10 -6 / ℃), thus, on the one hand, the deformation of the heating layer is small under the condition of hot and cold changes, and the use effect is better; on the other hand, the expansion coefficient of the above-mentioned metal magnetic material is made not much different from the expansion coefficient of the above-mentioned ceramic substrate, which reduces the risk of cracking of the ceramic substrate and the heating layer during sintering, and improves the tightness between the interface of the ceramic substrate and the heating layer, thereby reducing the interface thermal resistance of the ceramic substrate and the heating layer, improving the uniformity of heat transfer between the layers, and reducing the thermal stress generated by heat accumulation between the ceramic substrate and the heating layer in the subsequent heating process, thereby reducing the risk of cracking of the cooking container.

[0050] In an embodiment of the present invention, the thickness of the heating layer is 10 μm to 50 μm (specifically, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, etc.). It is understood that the thickness and sheet resistance of the heating layer can affect each other and further affect the heating power of the heating layer. Within the above thickness and sheet resistance ranges, a higher induction resistance can be achieved, thereby achieving a higher heating power.

[0051] In some embodiments, the sintering temperature of the heating layer is greater than 1000 degrees Celsius, preferably 1300-1700 degrees Celsius (specifically 1300 degrees Celsius, 1400 degrees Celsius, 1500 degrees Celsius, 1600 degrees Celsius, 1700 degrees Celsius, etc.). Therefore, due to the high melting point of the above-mentioned metal magnetic material, high-temperature glaze can be selected to be sintered and solidified on the surface of the heating layer. At this time, the sheet resistance of the heating layer is relatively stable, which is conducive to limiting the sheet resistance of the heating layer to the range of 1mΩ to 20mΩ, which is conducive to reducing the large fluctuation of the sheet resistance value of the heating layer during the preparation process of the cooking container. The risk of overheating is reduced, the controllability of the heating performance of the heating layer is improved, and the heating efficiency and heating uniformity of the heating layer are further improved. The high-temperature glaze has the advantages of high stability, high temperature resistance and good resistance to cold and hot shocks. The first glaze layer formed by the high-temperature glaze better protects the heating layer, makes the square resistance of the heating layer more stable, further improves the heating efficiency and heating uniformity of the heating layer, and at the same time extends the service life of the cooking container and reduces production costs. On the other hand, the first glaze layer can make the cooking container smooth and delicate, easy to clean, high hardness, better user experience, and can well protect the heating layer. In the prior art, the heating layer formed by low-melting-point materials such as silver and aluminum needs to be sintered and solidified with low-temperature glaze on the surface of the heating layer in order to reduce the damage to the heating layer caused by high-temperature sintering. The glaze layer formed by low-temperature sintering has poor stability, is not resistant to high temperatures, and has low resistance to cold and hot shocks. It is easily damaged and has poor protection for the heating layer. The glaze required for low-temperature sintering has poor stability, which increases the production cost. Moreover, since the sintering temperature of the low-temperature glaze is usually not much different from the melting point of low-melting-point materials such as silver and aluminum, it is also easy to cause the heating layer to be damaged and unstable, thereby causing the square resistance of the heating layer to be unstable and the heating performance to be poor.

[0052] In an embodiment of the present invention, the above-mentioned metal magnetic material is tungsten. Therefore, firstly, the metal tungsten layer has a relatively high melting point (3410°C), and the tungsten heating layer formed is not easy to melt. In subsequent steps, high-temperature glaze can be used to sinter the surface of the tungsten heating layer. The first glaze layer formed by the high-temperature glaze better protects the tungsten heating layer, making the square resistance of the tungsten heating layer more stable, and further improving the heating efficiency and heating uniformity of the tungsten heating layer; secondly, metal tungsten is very stable in the air, and slight oxidation will occur only when the temperature reaches 400°C. In the present invention, since the tungsten heating layer is located inside the ceramic pot, heat can be transferred to food very quickly, and the heating efficiency is extremely high. During the process, the temperature of the pot will not exceed 250°C, and there is The glaze layer protects it, so the reliability of metal tungsten is very high, and the thermal resistance will not change significantly even after long-term aging, ensuring the power stability during long-term use; thirdly, the shrinkage rate or expansion coefficient of metal tungsten and ceramics is not much different. On the one hand, the risk of cracking of the ceramic substrate and the heating layer during sintering is reduced, and on the other hand, the close connection between the interface of the ceramic substrate and the heating layer is improved, thereby reducing the interfacial thermal resistance of the ceramic substrate and the heating layer, improving the uniformity of heat transfer between the layers, and reducing the thermal stress generated by heat accumulation between the ceramic substrate and the heating layer in the subsequent heating process, thereby reducing the risk of cracking of the cooking container; fourthly, metal tungsten has good conductivity and small electronic work function, which is very suitable for heating.

[0053] In some embodiments, at least a portion of the heating layer away from the center of the bottom wall of the cooking container has a tendency to gradually decrease in thickness. Due to the high heating efficiency of the heating layer, uneven heating of the bottom wall of the cooking container is prone to occur. By setting at least a portion of the heating layer away from the center of the bottom wall of the cooking container to have a tendency to gradually decrease in thickness, the resistance of the heating layer away from the center of the bottom wall of the cooking container is gradually reduced, and the efficiency of current transfer is gradually increased, thereby improving the uniformity of heating of the bottom wall of the cooking container.

[0054] In some embodiments, the heating layer extends from the bottom wall to the side wall of the cooking container, and the average thickness of the heating layer at the side wall is less than the average thickness of the heating layer at the bottom wall. Since the ceramic substrate conducts heat slowly, the side wall of the cooking container is heated slowly, which easily causes uneven heating of the bottom wall and side wall of the cooking container. By setting the average thickness at the side wall to be less than the average thickness at the bottom wall, the resistance of the heating layer at the side wall is reduced, the efficiency of current transfer toward the side wall is improved, and the temperature uniformity of the cooking container is improved.

[0055] In some embodiments, the thickness of the heating layer arranged on the upper part of the side wall of the cooking container is smaller than the thickness of the heating layer arranged on the lower part of the side wall of the cooking container, and the heating layer on the upper part of the side wall and the heating layer on the lower part of the side wall are smoothly transitioned and connected. Therefore, the upper part of the side wall is usually not affected by the heating element, which mainly serves as a conductor. Therefore, the thickness of the heating layer on the upper part of the side wall is set to be thinner, which reduces the resistance of the heating layer on the upper part of the side wall, increases the flow of current in the heating layer on the upper part of the side wall, increases the heat generation of the upper part of the side wall of the cooking container, and thus improves the uniformity of the temperature of the side wall of the cooking container.

[0056] In some embodiments, the thickness of the connection between the heating layer at the upper part of the side wall and the heating layer at the lower part of the side wall changes gradually, thereby avoiding heat concentration caused by sudden changes in thickness and reducing the risk of rupture of the heating layer due to internal stress.

[0057] In some embodiments, the heating layer includes a transition connection layer and a metal layer, the metal layer includes a metal magnetic material and a glass phase, the glass phase in the metal layer fills the gaps between the metal magnetic materials, the transition connection layer includes a glass phase, and the ceramic substrate is connected to the metal layer through the transition connection layer. Therefore, by setting the metal layer to include a metal magnetic material and a glass phase, the distribution of the metal magnetic material in the metal layer is more uniform, so that the heat generated by the metal magnetic material will not be concentrated in large quantities, reducing the formation of hot spots in the metal layer and the ceramic substrate, reducing the risk of cracking of the ceramic substrate, improving the service life of the ceramic substrate, and also improving the bonding strength between the ceramic substrate and the heating layer; at the same time, the transition connection layer includes a glass phase, since there is also an interface thermal resistance between the transition connection layer and the ceramic substrate, thereby further reducing the rate at which the heat generated by the metal magnetic material is transferred to the ceramic substrate, thereby reducing the formation of hot spots in the ceramic substrate, reducing the risk of cracking of the ceramic substrate, improving the service life of the ceramic substrate, and also improving the bonding strength between the ceramic substrate and the heating layer.

[0058] In some embodiments, the glass phase in the metal layer and the glass phase in the transition connecting layer are interconnected. Thus, the glass phase in the transition connecting layer and the glass phase in the metal layer are interconnected, further promoting the uniform dispersion of heat in the transition connecting layer, reducing the formation of hot spots in the metal layer, avoiding the formation of thermal stress, and thereby improving the bonding strength between the transition connecting layer and the metal layer.

[0059] In some embodiments, the metal magnetic material is embedded in the glass phase of the transition connection layer, further increasing the contact area between the metal magnetic material and the transition connection layer, increasing the area of ​​heat transfer, thereby improving the uniformity of heat transfer, avoiding the formation of hot spots in the heating layer, and further reducing the risk of microcracks inside the heating layer.

[0060] The above-mentioned transition connection layer can be formed by applying inorganic glaze, or by controlling the content of inorganic glaze in the heating layer or controlling the sintering process (such as sintering temperature, sintering time), etc. As long as a heating layer including a transition connection layer and a metal layer can be formed, its specific preparation process is not subject to special restrictions.

[0061] In some embodiments, the materials of the glass phase in the transition connecting layer and the glass phase in the metal layer independently include at least one selected from aluminum oxide, silicon oxide, lithium oxide, titanium oxide, potassium oxide and sodium oxide. Therefore, the glass phase formed by the above materials can provide suitable thermal resistance between the metal magnetic sensitive material and the ceramic substrate, avoiding the formation of hot spots in the ceramic substrate, so that the heat can be dispersed and transferred more evenly.

[0062] In some embodiments, referring to Figure 1 The cooking container may further include a first glaze layer 40, which is arranged on at least a portion of the surface of the heating layer 30 away from the ceramic substrate 10. The sintering temperature of the first glaze layer is greater than 1000 degrees Celsius, preferably 1100-1200 degrees Celsius (specifically 1100 degrees Celsius, 1150 degrees Celsius, 1200 degrees Celsius, etc.). Therefore, on the one hand, due to the high melting point of the metal magnetic material in the heating layer, the heating layer is not easy to melt. High-temperature glaze can be used here to sinter the surface of the heating layer. The high-temperature glaze has the advantages of high stability, high temperature resistance and good resistance to cold and hot shocks. The first glaze layer formed by the high-temperature glaze better protects the heating layer, makes the square resistance of the heating layer more stable, further improves the heating efficiency and heating uniformity of the heating layer, and at the same time extends the service life of the cooking container and reduces production costs. On the other hand, the first glaze layer can make the cooking container smooth and delicate, easy to clean, high hardness, good user experience, and can well protect the heating layer.

[0063] In some embodiments, referring to Figure 1 The cooking container may further include a second glaze layer 20, which is arranged on at least a portion of the outer surface of the ceramic substrate 10. Thus, the second glaze layer can make the cooking container smooth and delicate, easy to clean, and have high hardness, thereby improving the impact resistance of the cooking container, providing a better user experience, and being able to well protect the ceramic substrate.

[0064] Furthermore, the sintering temperature of the second glaze layer is greater than 1000 degrees Celsius, preferably 1100-1200 degrees Celsius (specifically 1100 degrees Celsius, 1150 degrees Celsius, 1200 degrees Celsius, etc.). Therefore, due to the high sintering temperature of the second glaze layer, a high-temperature glaze matching the sintering temperature must be selected. The high-temperature glaze has the advantages of high stability, high temperature resistance, and good resistance to cold and hot shocks. The second glaze layer formed by the high-temperature glaze better protects the ceramic substrate and further improves the impact resistance of the cooking container. At the same time, due to the high melting point of the metal magnetic material in the heating layer, the heating layer is not easy to melt and is not easily damaged in the subsequent high-temperature sintering step. It is relatively stable, so that the heating layer can be prepared on the ceramic substrate first, and then the heating layer can be simultaneously The first glaze layer is formed on the surface away from the ceramic substrate and the second glaze layer is formed on the outer surface of the ceramic substrate, which reduces the complexity of the process, improves the consistency of the appearance of the ceramic container, and improves the stability of the ceramic container. The heating layer formed by low-melting-point materials such as silver and aluminum in the prior art is easily damaged and unstable in the subsequent high-temperature sintering step. In order to improve the stability of the outer surface of the ceramic substrate, it is necessary to prepare a high-temperature glaze layer on the outer surface of the ceramic substrate. Therefore, it is necessary to prepare a high-temperature second glaze layer on the outer surface of the ceramic substrate before preparing the heating layer, and then prepare a lower-temperature glaze layer on its surface after the heating layer is prepared to protect the heating layer. Not only is the process complicated, but it also reduces the consistency of the container's appearance and the stability of the container. In addition, the second glaze layer can make the cooking container smooth and delicate, easy to clean, high in hardness, and better in user experience.

[0065] According to an embodiment of the present invention, the thickness of the second glaze layer and the first glaze layer can be independently 100 μm to 500 μm (specifically, 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm, 500 μm, etc.). Within this thickness range, good heating uniformity can be ensured, and the stress of the first and second glaze layers is small, the resistance to cold and hot shock is better, and it is not easy to crack.

[0066] In some embodiments, the expansion coefficient of the first glaze layer measured at 100-300 degrees Celsius is 0.5×10 -6 ~2×10 -6 / ℃(Specifically, 0.5×10 -6 / ℃、0.8×10 -6 / ℃、1×10 -6 / ℃、1.2×10 -6 / ℃、1.5×10 -6 / ℃、1.8×10 -6 / ℃、2×10 -6 / ℃, etc.), thus, the deformation of the first glaze layer is small under the change of temperature, the use effect is better, and the matching with the metal layer is better, thus better protecting the metal layer. In some embodiments, the expansion coefficient of the second glaze layer measured at 100-300 degrees Celsius is 0.5×10 -6 ~2×10 -6 / ℃(Specifically, 0.5×10 -6 / ℃、0.8×10 -6 / ℃、1×10 -6 / ℃、1.2×10 -6 / ℃、1.5×10 -6 / ℃、1.8×10 -6 / ℃、2×10 -6 / °C, etc.). As a result, the second glaze layer exhibits minimal deformation under thermal fluctuations, resulting in better performance, better compatibility with the ceramic substrate, and improved protection of the ceramic substrate. It should be noted that the expansion coefficient of the first glaze layer and the expansion coefficient of the second glaze layer may be the same or different.

[0067] In an embodiment of the present invention, the specific type of material of the above-mentioned first glaze layer is not particularly limited, and those skilled in the art can choose it at will according to actual conditions. As a specific example, the material of the first glaze layer includes at least one selected from aluminum oxide, silicon oxide, lithium oxide, titanium oxide, potassium oxide and sodium oxide. Therefore, the above-mentioned type of inorganic glaze has the advantages of high stability, high temperature resistance and good resistance to cold and hot shocks. The first glaze layer formed by the high-temperature glaze better protects the heating layer, makes the square resistance of the heating layer more stable, further improves the heating efficiency and heating uniformity of the heating layer, and at the same time extends the service life of the cooking container and reduces production costs.

[0068] In an embodiment of the present invention, the specific type of material of the above-mentioned second glaze layer is not particularly limited, and those skilled in the art can freely choose it according to actual conditions. As a specific example, the material of the second glaze layer includes at least one selected from aluminum oxide, silicon oxide, lithium oxide, titanium oxide, potassium oxide and sodium oxide. Therefore, the above-mentioned type of inorganic glaze has the advantages of high stability, high temperature resistance and good resistance to cold and hot shocks. The second glaze layer formed by the high-temperature glaze better protects the ceramic substrate and further improves the impact resistance of the cooking container.

[0069] In some embodiments, the second glaze layer and the first glaze layer are connected at the container mouth of the cooking container, and the first glaze layer and the second glaze layer are connected with a smooth transition, thereby making the connection smoother and further improving the impact resistance of the container mouth.

[0070] According to an embodiment of the present invention, the heating layer can be coated by thermal spraying, compressed air spraying, pad printing, or screen printing, and then sintered. The specific thermal spraying, compressed air spraying, pad printing, or screen printing, and sintering steps can be performed with reference to conventional techniques and will not be described in detail here.

[0071] As mentioned above, the heating layer can be composed only of metal magnetic material, or it can be composed of metal magnetic material and glass phase. In some specific embodiments, when the heating layer is composed only of metal magnetic material, it can be coated by a thermal spraying method (for example, including but not limited to flame spraying), and then the above-mentioned sintering is performed. When the heating layer is composed of metal magnetic material and glass phase, it is necessary to first prepare a slurry including metal magnetic material and inorganic glaze, and then coat it by air compression spraying, pad printing or screen printing, and then level it at room temperature for 5min to 15min (such as 5min, 6min, 7min, 8min, 9min, 10min, 11min, 12min, 13min, 14min, 15min, etc.), and then sinter it in a drying furnace at 100℃ to 150℃ (such as 100℃, 110℃, 120℃, 130℃, 140℃, 150℃, etc.) for 10min to 15min (such as 10m in, 11min, 12min, 13min, 14min, 15min, etc.), and then sintered in a tunnel furnace. The tunnel furnace is required to be a vacuum environment or a reducing atmosphere such as hydrogen. The sintering temperature can be 1300℃~1700℃ (such as 1300℃, 1350℃, 1400℃, 1450℃, 1500℃, 1550℃, 1600℃, 1650℃, 1700℃, etc.), and the peak temperature is maintained for 30min~45min (such as 30min, 32min, 35min, 38min, 40min, 42min, 45min, etc.). The inorganic glaze after sintering becomes a glass phase.

[0072] According to an embodiment of the present invention, the first glaze layer and the second glaze layer can be formed from conventional high-temperature ceramic glazes. The specific sintering temperature of the first glaze layer and the second glaze layer (i.e., the sintering temperature when preparing the first glaze layer and the second glaze layer) can be greater than 1000°C (e.g., 1100°C to 1200°C). The specific composition can be consistent with conventional ceramic glazes, which will not be described in detail here. As a result, the raw materials for the first glaze layer and the second glaze layer are easily available and low in cost. The formed first glaze layer and the second glaze layer have beautiful brightness and gloss, high hardness, and are easy to clean. The thermal expansion coefficient matches the ceramic substrate well, and is not easily cracked by hot and cold shocks, resulting in better performance and better stability.

[0073] According to an embodiment of the present invention, referring to Figure 1The second glaze layer 20 can cover the entire outer surface of the ceramic substrate 10, and the first glaze layer 40 can cover the entire inner surface of the ceramic substrate. That is, when the heating layer 30 only covers part of the inner surface of the ceramic substrate, the first glaze layer 40 covers the surface of the heating layer 30 away from the ceramic substrate 10 and the inner surface of the ceramic substrate 10 not covered by the heating layer 30 (refer to Figure 1 ), and when the heating layer covers the entire inner surface of the ceramic substrate, the first glaze layer 40 covers the entire surface of the heating layer away from the ceramic substrate.

[0074] In some embodiments, referring to Figure 5 The cooking container may further include a third glaze layer 50, which is disposed on the inner surface of the ceramic substrate 10, the heating layer 30 is disposed on the surface of the third glaze layer 50 away from the ceramic substrate 10, and the first glaze layer 40 is disposed on the surface of the heating layer 30 away from the ceramic substrate 10 and the surface of the third glaze layer 50 away from the ceramic substrate 10 that is not covered by the heating layer 30.

[0075] Specifically, the composition of the third glaze layer can be the same as that of the second glaze layer, which will not be described in detail here. The thickness of the third glaze layer can also be 100μm to 500μm (specifically, 100μm, 150μm, 200μm, 250μm, 300μm, 350μm, 400μm, 450μm, 500μm, etc.). Within this thickness range, good heating uniformity can be ensured, and the third glaze layer has less stress, better resistance to thermal shock, and is less prone to cracking.

[0076] According to an embodiment of the present invention, the second glaze layer can be formed by coating and sintering in sequence. Specifically, the coating can be dip coating or spray coating. Specifically, the outer surface of the ceramic substrate can be immersed in a container containing a coating for forming the second glaze layer, and after a suitable time, it can be taken out of the container and the excess coating can be returned to the coating container; or the coating or powder forming the second glaze layer can be directly sprayed on the outer surface of the ceramic substrate. After the coating is completed, the ceramic substrate with the coating layer is sintered to form the second glaze layer. Specifically, the sintering temperature can be greater than 1000°C, and the sintering time can be adjusted according to actual needs. The present invention does not impose any restrictions on this. It can be understood that the steps of forming the first glaze layer can be the same as the steps of forming the second glaze layer, and will not be described in detail here.

[0077] In some embodiments, a third glaze layer can be formed simultaneously during the step of forming the second glaze layer. As previously described, the composition of the third glaze layer can be the same as that of the second glaze layer. It is understood that the second and third glaze layers can be formed in a single step. Specifically, in the coating step, a coating layer can be formed simultaneously on the inner and outer surfaces of the ceramic substrate, followed by sintering to simultaneously form the second and third glaze layers.

[0078] It should be noted that there is no special restriction on the order of forming the heating layer, the first glaze layer and the second glaze layer. In some embodiments, the heating layer can be formed first, and then the first glaze layer and the second glaze layer are formed. It can be understood that at this time, the second glaze layer and the first glaze layer can be formed synchronously. Specifically, a coating layer can be formed by dipping or spraying on the outer surface of the ceramic substrate, the surface of the heating layer away from the ceramic substrate, and the inner surface of the ceramic substrate not covered by the heating layer, and then sintering. In other embodiments, the second glaze layer can be formed first, and then the heating layer and the first glaze layer are formed in sequence. In still other embodiments, the second glaze layer and the third glaze layer can be formed synchronously first, and then the heating layer and the first glaze layer are formed in sequence.

[0079] In another aspect of the present invention, the present invention provides a cooking device. Figure 6 The cooking device comprises the aforementioned cooking container 100 and a magnetic field generator 200, which provides an alternating magnetic field to heat the heating layer in the cooking container via electromagnetic induction. This cooking device combines the advantages of the aforementioned cooking container with electromagnetic induction heating, offering high heating efficiency, high heat utilization, and excellent heating uniformity.

[0080] It is understood that there are no specific restrictions on the specific type of magnetic field generating device, as long as it can effectively generate an alternating magnetic field and stimulate the heating layer in the cooking container to induce eddy currents and generate heat. In some specific embodiments, the magnetic field generating device is an electromagnetic coil. This provides a simple, convenient, and easy-to-implement structure.

[0081] Specifically, there are no special restrictions on the specific type of cooking equipment, including but not limited to rice cookers, electric pressure cookers, electric stew pots, electric frying pans, etc. It can be understood that in addition to the cooking container and magnetic field generating device mentioned above, the cooking equipment also has the necessary structures and components of conventional cooking equipment. Taking the rice cooker as an example, it can also include a cooker body, an upper cover connected to the cooker body, an anti-overflow part provided on the upper cover, buttons or touch panels provided on the upper cover or the cooker body, a power cord, necessary circuit structures, etc., which will not be repeated here.

[0082] The following embodiments of the present invention are described in detail. It should be noted that the embodiments described below are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention. In addition, unless otherwise expressly stated, all raw materials used in the following embodiments are commercially available or can be synthesized according to methods described herein or known methods. Reaction conditions not listed are also readily available to those skilled in the art.

[0083] Example 1

[0084] This embodiment provides a ceramic cookware, and the preparation method thereof is as follows:

[0085] (1) In a mold, a ceramic blank is shaped by spinning, and then surface-dried to obtain a ceramic substrate with a thickness of 5 mm, wherein the main component of the ceramic substrate is wollastonite;

[0086] (2) A second glaze layer having a thickness of 300 μm was formed on the outer surface of the ceramic substrate. Specifically, a second glaze layer slurry was first prepared, and then the second glaze layer slurry was directly sprayed onto the outer surface of the ceramic substrate. After the coating was completed, the ceramic substrate with the coating layer was sintered at a high temperature of 1200 degrees Celsius to form the second glaze layer. The second glaze layer slurry was a dispersion of ethanol and inorganic glaze (including aluminum oxide, silicon oxide, lithium oxide, titanium oxide, potassium oxide, and sodium oxide), with a solid content of 75 wt%.

[0087] (3) A tungsten heating layer with a thickness of 30 μm is made on the inner surface of the ceramic substrate. Specifically, the heating layer slurry is first prepared, and then coated on the inner surface of the ceramic substrate by screen printing. Then, it is leveled at room temperature for 10 minutes, and then sintered in a drying furnace at 120°C for 12 minutes. Then, it is sintered in a tunnel furnace. The tunnel furnace is required to be a vacuum environment. The sintering temperature can be 1500°C and maintained at the peak temperature for 40 minutes to form a tungsten heating layer. The above-mentioned heating layer slurry is a dispersion of metal tungsten, ethanol and inorganic glaze (including aluminum oxide, silicon oxide, lithium oxide, titanium oxide, potassium oxide and sodium oxide, etc.), with a solid content of 75wt%. The content of metallic tungsten in the heating layer is 75wt%, the thickness of the heating layer is 15μm, and the square resistance of the tungsten heating layer is tested, and the test result is 8mΩ; when paired with the electromagnetic induction coil disk of the ceramic cookware, using a bridge meter, under the conditions of an operating voltage of 1V and a frequency of 25KHz, its induction resistance is tested to be 3.5Ω, which can meet the induction resistance requirements of the electromagnetic induction system of the ceramic cookware (within the range of 2-4.5Ω).

[0088] (4) A first glaze layer with a thickness of 300 μm is made on the surface of the tungsten heating layer away from the ceramic substrate. Specifically, the first glaze layer slurry is first prepared, and then the first glaze layer slurry is directly sprayed on the surface of the tungsten heating layer. After the coating is completed, it is placed at a high temperature of 1200 degrees Celsius for sintering. The sintering process adopts sintering under a vacuum atmosphere to form the first glaze layer. The above-mentioned first glaze layer slurry is a dispersion of ethanol and inorganic glaze (including aluminum oxide, silicon oxide, lithium oxide, titanium oxide, potassium oxide and sodium oxide, etc.), with a solid content of 75wt%. Thus, the ceramic cookware is prepared. The induction resistance is tested by a bridge meter under the same debugging and is 3.45Ω, which is basically unchanged and meets the requirements of electronic control.

[0089] Example 2

[0090] The difference from Example 1 is that the content of metal tungsten in the heating layer is 85wt%, the thickness of the heating layer is 15μm, and the square resistance of the tungsten heating layer is tested, and the test result is 6mΩ; when paired with a ceramic cookware electromagnetic induction coil disk, using a bridge meter, under the conditions of an operating voltage of 1V and a frequency of 25KHz, its induction resistance is tested to be 4.2Ω, which can meet the induction resistance requirements of the ceramic cookware electromagnetic induction system.

[0091] After the ceramic cookware was prepared, its induction resistance was tested with a bridge meter under the same debugging conditions and was found to be 4.18Ω, with basically no change, which met the electronic control requirements.

[0092] Example 3

[0093] The difference from Example 1 is that the content of metal tungsten in the heating layer is 65wt%, the thickness of the heating layer is 15μm, and the square resistance of the tungsten heating layer is tested, and the test result is 13mΩ; when paired with a ceramic cookware electromagnetic induction coil disk, using a bridge meter, under the conditions of an operating voltage of 1V and a frequency of 25KHz, its induction resistance is tested to be 2.85Ω, which can meet the induction resistance requirements of the ceramic cookware electromagnetic induction system.

[0094] After the ceramic cookware was prepared, its induction resistance was tested with a bridge meter under the same debugging conditions and was found to be 2.83Ω, with basically no change, which met the electronic control requirements.

[0095] Example 4

[0096] The difference from Example 1 is that the content of metal tungsten in the heating layer is 70wt%, the thickness of the heating layer is 15μm, and the square resistance of the tungsten heating layer is tested, and the test result is 10mΩ; when paired with a ceramic cookware electromagnetic induction coil disk, using a bridge meter, under the conditions of an operating voltage of 1V and a frequency of 25KHz, its induction resistance is tested to be 3.16Ω, which can meet the induction resistance requirements of the ceramic cookware electromagnetic induction system.

[0097] After the ceramic cookware was prepared, its induction resistance was tested with a bridge meter under the same debugging conditions and was found to be 3.12Ω, with basically no change, which met the electronic control requirements.

[0098] Example 5

[0099] The difference from Example 1 is that the content of metal tungsten in the heating layer is 60wt%, the thickness of the heating layer is 15μm, and the square resistance of the tungsten heating layer is tested, and the test result is 16mΩ; when paired with a ceramic cookware electromagnetic induction coil disk, using a bridge meter, under the conditions of an operating voltage of 1V and a frequency of 25KHz, its induction resistance is tested to be 2.65Ω, which can meet the induction resistance requirements of the ceramic cookware electromagnetic induction system.

[0100] After the ceramic cookware was prepared, its induction resistance was tested with a bridge meter under the same debugging conditions and was found to be 2.6Ω, with basically no change, which met the electronic control requirements.

[0101] Example 6

[0102] The difference from Example 1 is that the content of metal tungsten in the heating layer is 90wt%, the thickness of the heating layer is 15μm, and the square resistance of the tungsten heating layer is tested, and the test result is 3mΩ; when paired with a ceramic cookware electromagnetic induction coil disk, using a bridge meter, under the conditions of an operating voltage of 1V and a frequency of 25KHz, its induction resistance is tested to be 4.46Ω, which can meet the induction resistance requirements of the ceramic cookware electromagnetic induction system.

[0103] After the ceramic cookware was prepared, its induction resistance was tested with a bridge meter under the same debugging conditions and was found to be 4.45Ω, with basically no change, which met the electronic control requirements.

[0104] Comparative Example 1

[0105] In this comparative example, the metal magnetic material used in the heating layer is silver, and the other contents are the same as those in Example 1. Before making the first glaze layer on the surface of the silver heating layer, the electromagnetic induction coil disk of the ceramic cookware is matched with it, and the induction resistance is tested with a bridge meter under the conditions of an operating voltage of 1v and a frequency of 25KHz, which is 4.45Ω, which can meet the requirements of the electromagnetic induction system of the ceramic cookware for induction resistance. After making the first glaze layer on the surface of the silver heating layer, the induction resistance is tested with a bridge meter under the same debugging conditions and is 0.86Ω. The induction resistance has dropped significantly, which is related to the oxidation of the silver heating layer during the high-temperature sintering of the first glaze layer. The electromagnetic induction resistance is relatively small, resulting in the ceramic cookware having low actual power and high temperature rise of electronic components when used with the electromagnetic induction system, which does not meet the requirements of the electric control.

[0106] Comparative Example 2

[0107] In this comparative example, the metal magnetic material used in the heating layer is aluminum, and the other contents are the same as in Example 1. Before making the first glaze layer on the surface of the aluminum heating layer, it is matched with the electromagnetic induction coil disk of the ceramic cookware, and the induction resistance is tested with a bridge meter under the conditions of an operating voltage of 1v and a frequency of 25KHz. It is 2.53Ω, which can meet the requirements of the electromagnetic induction system of the ceramic cookware for induction resistance. After making the first glaze layer on the surface of the aluminum heating layer, the induction resistance is tested with a bridge meter under the same debugging conditions and is 0.05Ω. The induction resistance has dropped significantly, which is related to the oxidation of the aluminum heating layer during the high-temperature sintering of the first glaze layer. The electromagnetic induction resistance is relatively small, resulting in the ceramic cookware having low actual power and high temperature of electronic components when used with the electromagnetic induction system, which does not meet the requirements of the electric control.

[0108] It can be seen that the induction resistance of the ceramic cookware using tungsten heating layers in Examples 1-6 of the present invention meets the induction resistance requirements of the ceramic cookware electromagnetic induction system. After sintering the high-temperature glaze layer, the induction resistance remains essentially unchanged, meeting the electronic control requirements. In contrast, in Comparative Examples 1 and 2, which use silver and aluminum heating layers, respectively, the induction resistance decreases significantly after sintering the high-temperature glaze layer, resulting in a relatively low electromagnetic induction resistance. This results in low actual power consumption and increased temperature of electronic components when used with the electromagnetic induction system, failing to meet the electronic control requirements.

[0109] In the description of the present invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0110] In the present invention, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0111] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0112] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A cooking container, characterized in that: include: Ceramic substrate; a heating layer, the heating layer being disposed on at least a portion of the inner surface of the ceramic substrate, the heating layer having a sheet resistance of 1 mΩ to 20 mΩ, and comprising a metallic magnetic material having a melting point greater than 1000 degrees Celsius and a relative magnetic permeability less than 10; a first glaze layer, the first glaze layer being disposed on at least a portion of the surface of the heating layer away from the ceramic substrate, the sintering temperature of the first glaze layer being greater than 1000 degrees Celsius; The heating layer includes a transition connection layer and a metal layer, the metal layer includes a metal magnetic material and a glass phase, the transition connection layer includes a glass phase, and the ceramic substrate is connected to the metal layer through the transition connection layer; The metallic magnetically sensitive material is embedded in the glass phase of the transition connecting layer; and / or the glass phase in the metallic layer and the glass phase in the transition connecting layer are connected to each other.

2. The cooking container according to claim 1, characterized in that The relative magnetic permeability of the metallic magnetic material is greater than 1 and less than 10.

3. The cooking container according to claim 1, wherein The sintering temperature of the first glaze layer is 1100-1200 degrees Celsius.

4. The cooking container according to claim 1, wherein The content of the metal magnetic material in the heating layer is 60-90wt%; And / or, the difference between the expansion coefficient of the ceramic substrate and the expansion coefficient of the metallic magnetic material is within the range of ±30%.

5. The cooking container according to any one of claims 1 to 4, characterized in that: At least one of the following conditions is met: The electrical conductivity of the metal magnetic material measured at 20 degrees Celsius is ≤7*10 -8 S / m; The expansion coefficient of the metal magnetic material measured at 100-300 degrees Celsius is 1*10 -6 ~3*10 -6 / ℃; The expansion coefficient of the ceramic substrate measured at 100-300 degrees Celsius is 0.5×10 -6 ~2×10 -6 / ℃.

6. The cooking container according to any one of claims 1 to 4, characterized in that: The sintering temperature of the heating layer is greater than 1000 degrees Celsius.

7. The cooking container according to claim 6, characterized in that The sintering temperature of the heating layer is 1300-1700 degrees Celsius.

8. The cooking container according to any one of claims 1 to 4, characterized in that: The metal magnetic material is tungsten.

9. The cooking container according to any one of claims 1 to 4, characterized in that: Also includes: A second glaze layer is disposed on at least a portion of the outer surface of the ceramic substrate.

10. The cooking container according to claim 9, characterized in that The sintering temperature of the second glaze layer is greater than 1000 degrees Celsius.

11. The cooking container according to claim 9, characterized in that Meet at least one of the following conditions: The thickness of the first glaze layer and the second glaze layer are independently 100 μm to 500 μm; The expansion coefficients of the first glaze layer and the second glaze layer measured at 100-300 degrees Celsius are each independently 0.5×10 -6 ~2×10 -6 / ℃; The materials of the first glaze layer and the second glaze layer are independently selected from at least one of aluminum oxide, silicon oxide, lithium oxide, titanium oxide, potassium oxide and sodium oxide.

12. The cooking container according to claim 9, characterized in that The second glaze layer and the first glaze layer are smoothly transitioned and connected at the container opening of the cooking container.

13. The cooking container according to any one of claims 1 to 4, characterized in that: The thickness of the heating layer is 10 μm to 50 μm; And / or, at least a portion of the heat-generating layer away from the center of the bottom wall of the cooking container has a trend of gradually decreasing thickness.

14. The cooking container according to any one of claims 1 to 4, characterized in that: The heating layer extends from the bottom wall to the side wall of the cooking container, and the average thickness of the heating layer at the side wall is smaller than the average thickness of the heating layer at the bottom wall.

15. The cooking container according to any one of claims 1 to 4, characterized in that: The thickness of the heating layer arranged on the upper part of the side wall of the cooking container is smaller than the thickness of the heating layer arranged on the lower part of the side wall of the cooking container, and the heating layer on the upper part of the side wall and the heating layer on the lower part of the side wall are smoothly transitioned and connected.

16. The cooking container according to claim 15, characterized in that The thickness of the connection between the heat generating layer at the upper portion of the side wall and the heat generating layer at the lower portion of the side wall changes gradually.

17. The cooking container according to claim 1, wherein The materials of the glass phase in the transition connecting layer and the glass phase in the metal layer are independently selected from at least one of aluminum oxide, silicon oxide, lithium oxide, titanium oxide, potassium oxide and sodium oxide.

18. The cooking container according to any one of claims 1 to 4, characterized in that: The ratio of the area of ​​the heating layer covering the inner surface of the ceramic substrate to the area of ​​the inner surface of the ceramic substrate is 1 / 3 to 1.

19. The cooking container according to any one of claims 1 to 4, characterized in that: Meet at least one of the following conditions: The first glaze layer covers the surface of the heating layer away from the ceramic substrate and the inner surface of the ceramic substrate not covered by the heating layer; Also comprising a second glaze layer, wherein the second glaze layer covers the entire outer surface of the ceramic substrate; It also includes a third glaze layer, which is arranged on the inner surface of the ceramic substrate, and the heating layer is arranged on the surface of the third glaze layer away from the ceramic substrate, and the first glaze layer is arranged on the surface of the heating layer away from the ceramic substrate and on the surface of the third glaze layer not covered by the heating layer.

20. A cooking device, characterized in that: include: The cooking container according to any one of claims 1 to 19; as well as A magnetic field generating device is used to provide an alternating magnetic field so that the heating layer in the cooking container is heated by electromagnetic induction.

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