Cookware and method of manufacturing cookware

Abstract

The application provides a cooker and a method for manufacturing the same. The cooker comprises a cooker base and a non-stick coating layer formed on the cooker base. The non-stick coating layer comprises an amorphous material layer, a first nitrided region laminated on the outside of the amorphous material layer, and an oxidation treatment layer laminated on the outside of the first nitrided region. The non-stick coating layer further comprises a second nitrided region extending from the bottom of the first nitrided region to the cooker base. The amorphous material layer is formed of an amorphous material. The first nitrided region comprises a mixed layer of the amorphous material and a first nitride. The second nitrided region comprises a mixed layer of the cooker base material and a second nitride. The oxidation treatment layer is an oleophilic oxide layer and serves as a surface layer of the non-stick coating layer of the cooker. Thus, the cooker coating layer of the application has excellent non-stickiness, scratch resistance, bonding strength and corrosion resistance, thereby prolonging the service life of the cooker.

Description

Technical Field

[0001] This application relates to the field of non-stick materials technology, specifically to a cookware and a method of manufacturing the cookware. Background Technology

[0002] Existing non-stick cookware typically achieves its non-stick function by spraying a fluoropolymer coating onto the surface of a metal substrate. While non-stick coatings made with fluoropolymers offer excellent initial non-stick properties, they are easily damaged by spatulas and prone to aging or decomposition due to high temperatures during use. These issues have significantly impacted the lifespan of cookware coated with fluoropolymers, resulting in generally poor long-lasting non-stick performance.

[0003] Therefore, there remains an urgent need in the cookware manufacturing industry for cookware coatings that possess excellent non-stick properties, scratch resistance, adhesion, and corrosion resistance. Summary of the Invention

[0004] Therefore, the purpose of this application is to provide a cookware and a method for manufacturing the cookware, so as to solve the problems of existing cookware in terms of non-stick properties, scratch resistance, bonding strength and corrosion resistance.

[0005] According to a first aspect of this application, a cookware is provided, wherein the cookware includes a cookware substrate and a non-stick coating formed on the cookware substrate, the non-stick coating including an amorphous material layer, a first nitrided region stacked on the outside of the amorphous material layer, and an oxide treatment layer stacked on the outside of the first nitrided region, the non-stick coating further including a second nitrided region extending from the bottom of the first nitrided region to the cookware substrate, wherein the amorphous material layer is formed of an amorphous material, the first nitrided region includes a mixed layer of amorphous material and a first nitride, the second nitrided region includes a mixed layer of cookware substrate material and a second nitride, and the oxide treatment layer is an oleophilic oxide layer and serves as the surface layer of the non-stick coating of the cookware.

[0006] According to the cookware provided in the embodiments of this application, the amorphous material layer serves as the base layer of the non-stick coating. Due to its amorphous properties, the amorphous material layer possesses low surface energy, good wear resistance, corrosion resistance, and stability. Therefore, as the base layer of the non-stick coating, it can effectively improve the durability and stability of the coating. The first nitrided region is stacked on the outside of the amorphous material layer. The first nitrided region is mainly composed of a mixed layer of amorphous material and first nitride. The addition of the first nitride improves the overall hardness and wear resistance of the coating, and, together with the amorphous material, further enhances the coating's long-lasting non-stick performance. Furthermore, the first nitrided region covers the outside of the amorphous material layer, preventing corrosive media from entering between the cookware substrate and the amorphous material layer, ensuring that the non-stick coating is not easily detached and guaranteeing the cookware's corrosion resistance. The second nitrided region extends from the bottom of the first nitrided region through the amorphous material layer to the cookware substrate. This tightly connects the cookware substrate, the amorphous material layer, and the first nitrided region, forming a continuous and stable structure, enhancing the bonding force between the non-stick coating and the cookware substrate, making the entire coating more robust and durable. The oxide treatment layer, serving as the surface layer of the non-stick coating, is composed of a mixture of amorphous materials and oleophilic oxides. This composition ensures the basic non-stick properties of the coating, while the oleophilic oxides further optimize the non-stick properties by easily forming an oil film. In summary, the cookware coating according to this application possesses excellent non-stick properties, scratch resistance, adhesion, and corrosion resistance, making the cookware more durable (with a longer service life).

[0007] Specifically, the thickness of the amorphous material layer is 2μm-10μm; the thickness of the first nitrided region is 15μm-70μm; the thickness of the second nitrided region is 2μm-10μm; and / or the thickness of the oxide treatment layer is 1μm-3μm.

[0008] In these embodiments, each layer has a preset thickness, which can balance non-stick properties, corrosion resistance, and hardness while ensuring the adhesion between the non-stick coating and the cookware substrate, so as to achieve a cookware coating that has multiple excellent properties such as non-stick, scratch resistance, adhesion, and corrosion resistance.

[0009] In some embodiments, the surface energy of the oxidized layer is 30 to 50 dynes.

[0010] In these embodiments, the oxidized layer has a low surface energy, which reduces food adhesion, facilitates cleaning, enhances the user's cooking experience, and extends the lifespan of the cookware.

[0011] In some embodiments, the amorphous material is an iron-based amorphous material.

[0012] In these embodiments, the iron-based amorphous material has excellent wear resistance, hardness bonding strength and corrosion resistance, so the amorphous material layer formed therefrom can maintain all of the above superior properties.

[0013] In some embodiments, the amorphous material is a mixture of iron-based amorphous material and iron-based self-fluxing alloy. Based on the total weight of the amorphous material being 100%, the weight percentage of the iron-based amorphous material is 95%-98%, with the remainder being the iron-based self-fluxing alloy.

[0014] In these embodiments, a mixture of iron-based amorphous material and iron-based self-fluxing alloy is used as the amorphous material. Since the iron-based self-fluxing alloy has excellent wettability and self-fluxing properties, the addition of the iron-based self-fluxing alloy can form a good bond with the amorphous material, forming an amorphous material with excellent corrosion resistance and hardness. In this way, the wear resistance and corrosion resistance of the amorphous material layer of the cookware can be guaranteed.

[0015] In some embodiments, the chemical composition of the iron-based self-fluxing alloy includes C: 0.5%-0.6%, Si: 2%-3.5%, B: 1%-2%, Cr: 12%-14%, Ni: 28%-34%, and the balance Fe.

[0016] In these embodiments, the iron-based self-fluxing alloy with the above chemical composition and content has high strength, high hardness, good corrosion resistance and wettability, and can form a good bond with iron-based amorphous materials, further improving the performance and service life of cookware.

[0017] In some embodiments, based on the total weight of the iron-based amorphous material as 100%, the composition of the iron-based amorphous material includes 60% to 85% iron, 15% to 40% titanium, and the balance impurities, wherein the impurities include at least one of carbon, phosphorus, sulfur, aluminum, manganese, and copper.

[0018] In these embodiments, the iron content is between 60% and 85%, serving as the main component of the amorphous material and providing fundamental mechanical properties, ensuring good strength and stability. The titanium content is between 15% and 40%, which improves the hardness, wear resistance, and corrosion resistance of the amorphous material. Simultaneously, the addition of titanium can also improve the processing performance and thermal stability of the amorphous material. Impurities include at least one of carbon, phosphorus, sulfur, aluminum, manganese, and copper. Although these impurity elements are present in low amounts, their presence can significantly affect the performance of the amorphous material. For example, carbon can improve the hardness and wear resistance of the amorphous material, phosphorus and sulfur may affect the processing performance and toughness, while aluminum, manganese, and copper can adjust physical properties such as electrical and thermal conductivity. Iron-based amorphous materials with the above-mentioned components and contents possess excellent mechanical properties, corrosion resistance, and magnetic properties to meet the specific needs of cookware.

[0019] In some embodiments, the surface pores of the non-stick coating are filled with grease or silicone oil.

[0020] In these embodiments, the surface of the non-stick coating is filled with grease or silicone oil, thus optimizing non-stick properties by forming an "oil film." In addition, the pores are filled with grease or silicone oil, which can prevent corrosion from corrosive media and ensure the corrosion resistance of the coating on non-stick cookware.

[0021] According to a second aspect of this application, a method for manufacturing a cooker is provided, wherein the method for manufacturing the cooker includes:

[0022] An amorphous coating with a predetermined rough surface is formed on the cookware substrate by thermal spraying of an amorphous material;

[0023] The cookware substrate having the amorphous coating is nitrided such that nitrogen atoms form a first nitrided region with the amorphous coating and a second nitrided region with the cookware substrate, wherein the first nitrided region is located on the outer layer of the amorphous coating and the second nitrided region is located on the inner side of the first nitrided region and extends from the bottom of the first nitrided region to the cookware substrate;

[0024] The first nitrided region is oxidized to form an oxide treatment layer on the surface of the first nitrided region, thereby manufacturing a cookware. The first nitrided region includes a mixed layer of amorphous material and a first nitride, and the second nitrided region includes a mixed layer of cookware substrate material and a second nitride. The oxide treatment layer is an oleophilic oxide layer and serves as the surface layer of the non-stick coating of the cookware.

[0025] According to the method for manufacturing cookware provided in this application, an amorphous coating with a predetermined rough surface is formed on a cookware substrate by thermal spraying. The amorphous material possesses high hardness, high wear resistance, and good corrosion resistance, and the predetermined rough surface provides protection for the layer (oxidation layer) formed in subsequent processing. Next, the cookware substrate with the amorphous coating undergoes nitriding treatment. In this process, nitrogen atoms form a first nitrided region with the amorphous coating and a second nitrided region with the cookware substrate. The first nitrided region mainly consists of a mixed layer of amorphous material and a first nitride. The addition of the first nitride improves the overall hardness and wear resistance of the coating, and, together with the amorphous material, further enhances the coating's durable non-stick properties. The second nitrided region is located outside the first nitrided region and extends from the bottom of the first nitrided region to the cookware substrate, thus improving the bonding force between the cookware substrate and the first nitrided region, making the entire coating more robust and durable. Finally, the first nitrided region undergoes oxidation treatment to form an oxidation layer on its surface. The oxide treatment layer, serving as the surface layer of the non-stick coating, is composed of a mixture of amorphous materials and oleophilic oxides. This composition ensures the basic non-stick properties of the coating, while the oleophilic oxides further optimize the non-stick properties by easily forming an oil film. In summary, the cookware coating according to this application possesses excellent non-stick properties, scratch resistance, adhesion, and corrosion resistance, making the cookware more durable (with a longer service life).

[0026] In some embodiments, nitriding the cookware substrate with the amorphous coating includes: placing the cookware substrate with the amorphous coating in a nitriding furnace, introducing ammonia gas so that the volume percentage of ammonia gas in the nitriding furnace is not less than 90%, and adjusting the furnace temperature to 130°C to 150°C; then adjusting the ammonia gas flow rate to 700L / h to 1000L / h, then adjusting the furnace temperature to 530°C to 580°C, holding the temperature for 3h to 7h, and finally adjusting the ammonia gas flow rate to 300L / h to 500L / h, and reducing the furnace temperature to room temperature at a cooling rate of 2°C / min to 4°C / min.

[0027] In these embodiments, the above nitriding treatment can form nitrided regions with excellent properties. These nitrided regions not only improve the hardness and wear resistance of the cookware, but also enhance its corrosion resistance and non-stick properties, providing a good foundation for subsequent oxidation treatment and use.

[0028] In some embodiments, the step of oxidizing the first nitrided region includes: placing a cookware substrate having the first nitrided region in an oxygen infiltration furnace, adjusting the furnace temperature to 420°C to 540°C; continuously introducing distilled water into the oxygen infiltration furnace at a flow rate of 10 g / s to 15 g / s for 0.5 h to 6 h, and then reducing the furnace temperature to room temperature at a cooling rate of 2°C / min to 4°C / min.

[0029] In these embodiments, the above oxidation treatment can form an oxide layer with excellent properties. This oxide layer not only improves the non-stick properties of the cookware but also enhances its corrosion resistance and wear resistance, providing excellent protection for the cookware's use. Furthermore, the oxide layer is typically dark in color, ensuring the cookware's aesthetic appearance.

[0030] In some embodiments, the thickness of the amorphous coating is 20μm-70μm, the thickness of the oxide treatment layer is 1μm-3μm, the thickness of the first nitrided region is less than or equal to the thickness of the amorphous coating, and the thickness of the second nitrided region is 2μm-10μm.

[0031] In these embodiments, each layer has a preset thickness, which can balance non-stick properties, corrosion resistance, and hardness while ensuring the adhesion between the non-stick coating and the cookware substrate, so as to achieve a cookware coating that has multiple excellent properties such as non-stick, scratch resistance, adhesion, and corrosion resistance.

[0032] In some embodiments, the cookware substrate includes any one of an iron substrate, a magnesium substrate, a copper alloy substrate, an aluminum substrate, a stainless steel substrate, a titanium substrate, and a composite substrate formed from the above substrates.

[0033] In these embodiments, the method of manufacturing cookware is not limited to a certain base material, which brings more convenience to the manufacture of cookware.

[0034] In some embodiments, the amorphous material is a particulate material with an average particle size in the range of 30 μm to 70 μm.

[0035] In these embodiments, amorphous materials with an average particle size in the range of 30 μm to 70 μm can form an amorphous coating with a predetermined rough surface. Specifically, when the particle size of the amorphous material is less than 30 μm, it is easy to cause molten droplets in the formed thermal spray coating, resulting in a poor appearance. When the particle size is greater than 70 μm, the surface roughness of the formed thermal spray coating is large, resulting in a poor final appearance. In addition, amorphous materials in the range of 30 μm to 70 μm can better contact and bond with the cookware substrate surface. At the same time, the interlocking effect between particles can also improve the cohesive strength of the amorphous coating, making the amorphous coating more robust and reliable. Furthermore, amorphous materials in the range of 30 μm to 70 μm have good flowability and filling properties, enabling the formation of a dense amorphous coating during the spraying process, effectively reducing voids and defects in the amorphous coating. Attached Figure Description

[0036] The above and other objects and features of this application will become clearer from the following description of embodiments in conjunction with the accompanying drawings, in which:

[0037] Figure 1 This is a schematic diagram of the cross-sectional structure of the cookware provided in the embodiment of this application after being cut along the thickness direction;

[0038] Figure 2 yes Figure 1 Enlarged structural diagram at point I;

[0039] Figure 3 It is a structural diagram based on a cross-section cut open from the junction of the cookware substrate and the non-stick coating;

[0040] Figure 4 It is a structural diagram based on another cross-section after cutting through the junction of the cookware substrate and the non-stick coating. Detailed Implementation

[0041] The inventive concept of this application will be described in more detail below.

[0042] According to the first aspect of this application, a cooking utensil is provided, such as Figure 1 and Figure 2 As shown, the cookware includes a cookware substrate 10 and a non-stick coating formed on the cookware substrate 10. The non-stick coating includes an amorphous material layer 20, a first nitrided region 31 stacked on the outside of the amorphous material layer 20, and an oxide treatment layer 40 stacked on the outside of the first nitrided region 31. The non-stick coating also includes a second nitrided region 32 extending from the bottom of the first nitrided region 31 to the cookware substrate 10. The amorphous material layer 20 is formed of amorphous material, the first nitrided region 31 includes a mixed layer of amorphous material and a first nitride, the second nitrided region 32 includes a mixed layer of cookware substrate material and a second nitride, and the oxide treatment layer 40 is an oleophilic oxide layer and serves as the surface layer of the non-stick coating of the cookware.

[0043] According to the cookware provided in the embodiments of this application, the amorphous material layer 20 serves as the base layer of the non-stick coating. Due to its amorphous properties, the amorphous material layer possesses low surface energy, good wear resistance, corrosion resistance, and stability. Therefore, as the base layer of the non-stick coating, it can effectively improve the durability and stability of the coating. The first nitrided region 31 is stacked on the outside of the amorphous material layer 20. The first nitrided region 31 is mainly composed of a mixed layer of amorphous material and first nitride. The addition of the first nitride improves the overall hardness and wear resistance of the coating, and at the same time, it works together with the amorphous material to further enhance the long-lasting non-stick performance of the coating. Furthermore, the first nitrided region 31 covers the outside of the amorphous material layer 20, which can prevent corrosive media from entering between the cookware substrate 10 and the amorphous material layer 20, ensuring that the non-stick coating is not easily detached and guaranteeing the corrosion resistance of the cookware. The second nitrided region 32 extends from the bottom of the first nitrided region 31 through the amorphous material layer 20 to the cookware substrate 10. This tightly connects the cookware substrate 10, the amorphous material layer 20, and the first nitrided region 31, forming a continuous and stable structure. This enhances the adhesion between the non-stick coating and the cookware substrate, making the entire coating more robust and durable. The oxide treatment layer 40, as the surface layer of the non-stick coating, is composed of a mixture of amorphous material and oleophilic oxides. This composition ensures the basic non-stick properties of the coating, while the oleophilic oxides further optimize the non-stick properties by easily forming an oil film. In summary, the cookware coating according to this application possesses excellent non-stick properties, scratch resistance, adhesion, and corrosion resistance, making the cookware more durable (with a longer service life).

[0044] According to this application, the layers other than the oxide layer (amorphous material layer 20, first nitrided region 31) not only provide protection for the oxide layer but also possess a certain degree of non-stickness. Therefore, even if the oxide layer is worn, cooking can still be non-stick, ensuring the durability of the cookware. In addition, the amorphous material and the oleophilic oxide form a tight bond, making the oxide layer less prone to peeling or damage when subjected to external forces such as high temperature and friction.

[0045] Figure 1 This is a schematic diagram of the cross-sectional structure of the cookware provided in the embodiment of this application after being cut along the thickness direction. Figure 2 yes Figure 1 A magnified structural diagram at point I. (Refer to...) Figure 1 and Figure 2 The non-stick cookware 100 may include a cookware substrate 10 and a non-stick coating. According to this application, the non-stick coating may at least partially cover the inner surface of the cookware substrate 10, meaning that the non-stick coating may cover the bottom surface or the entire inner surface of the cookware substrate 10.

[0046] The accompanying drawings of this application show a schematic diagram of the structure after being cut open at the junction of the cookware substrate 10 and the non-stick coating. Figure 3This is a schematic diagram showing one of the cross-sections; Figure 4 This is a structural schematic diagram showing another cross-section of the structure. Figure 3 The image shows a structural example of the amorphous material layer 20 and the first nitrided region 31 at the junction of the cookware substrate 10 and the non-stick coating. Specifically, at the junction of the cookware substrate 10 and the non-stick coating, the amorphous material layer 20 and the first nitrided region 31 are alternately distributed. Figure 4 The image shows a structural example of the second nitrided region 32 and the cookware substrate 10 at the junction of the cookware substrate 10 and the non-stick coating. Specifically, at the junction of the cookware substrate 10 and the non-stick coating, the second nitrided region 32 and the cookware substrate 10 are interleaved.

[0047] Amorphous material layer 20

[0048] According to this application, the amorphous material layer 20 in the non-stick coating can be the untreated (oxidized / nitrided) portion of the amorphous coating formed in subsequent cookware manufacturing methods. As the base layer (bottom layer) of the non-stick coating, the amorphous material layer provides excellent wear resistance, corrosion resistance, and high-temperature stability. In some embodiments, the thickness of the amorphous material layer 20 is 2 μm-10 μm. This thickness ensures that the coating has sufficient strength and stability to withstand various conditions during cooking. At the same time, an appropriate thickness also contributes to good bonding with other layers. When the thickness is less than 2 μm, the nitriding process is costly; when the thickness is greater than 10 μm, the effect of strengthening hardness is not significant enough and cannot meet the stress and temperature change requirements of the cookware.

[0049] According to this application, the amorphous material layer 20 is formed on the inner surface of the cookware substrate 10 by an amorphous material, and has a certain degree of amorphization. As an example, the volume ratio of the amorphous phase in the amorphous material according to this application is in the range of 55%-70%, thereby exhibiting excellent properties in various aspects due to its amorphous characteristics. In some embodiments, the amorphous material is an iron-based amorphous material, which has excellent wear resistance, hardness bonding strength, and corrosion resistance. Therefore, the amorphous material layer formed therefrom can maintain the above-mentioned superior properties.

[0050] The amorphous materials according to this application will be described in detail below.

[0051] In some embodiments, the amorphous material is an iron-based amorphous material. Based on the total weight of the iron-based amorphous material as 100%, the chemical composition of the iron-based amorphous material includes 55% to 85% iron, 10% to 40% titanium, and the balance impurities, wherein the impurities include at least one of carbon, phosphorus, sulfur, aluminum, manganese, and copper. Thus, after subsequent oxidation, a more uniform color and a mixed layer comprising titanium oxide (TiO2) and iron oxide (Fe3O4) can be obtained, avoiding the impact on the user experience due to color differences between materials.

[0052] It should be noted that the "chemical composition" described in this application can be understood based on the general understanding of those skilled in the art, and it is different from "chemical substance." Specifically, chemical composition describes the elements or compounds contained within a substance, while chemical substance is an actual substance composed of these elements or compounds. Simply put, chemical substance is an actual existing substance, while chemical composition is the basis for the composition of these substances. That is to say, the iron-based amorphous material of this application is a mineral material formed by the mixture of the above-mentioned components, and not a crystalline or trace amorphous mixture formed by the direct mixing of the above-mentioned substances.

[0053] According to this application, a method for manufacturing an iron-based amorphous material is provided. Specifically, natural ilmenite can be processed to obtain the iron-based amorphous material according to this application. The main components of the natural ilmenite include titanium oxide, ferric oxide, ferrous oxide, magnesium oxide, and other compounds excluding the above. These other compounds include aluminum oxide, silicon oxide, and calcium carbonate. Based on the total weight of the natural ilmenite (100%), the weight percentages are: titanium oxide 45%-50%, ferric oxide 5%-10%, ferrous oxide 30%-35%, magnesium oxide 3%-6%, and the balance being other compounds. Obtaining iron-based amorphous materials from natural ilmenite involves two steps. The first step is to process the natural ilmenite (e.g., magnetic separation, flotation, gravity separation, or a combination of methods) to obtain titanium concentrate. The second step is to reduce the titanium concentrate to iron-based amorphous materials. Based on the total weight of the iron-based amorphous materials (100%), the chemical composition includes 55% to 85% iron, 10% to 40% titanium, and the balance being impurities. The iron content, between 60% and 85%, as the main component of the amorphous material, provides fundamental mechanical properties, ensuring good strength and stability. The titanium content, between 15% and 40%, can improve the hardness, wear resistance, and corrosion resistance of the amorphous material. Simultaneously, the addition of titanium can also improve the processing performance and thermal stability of the amorphous material. Impurities include at least one of carbon, phosphorus, sulfur, aluminum, manganese, and copper. Although these impurity elements are present in low amounts, their presence can have a significant impact on the properties of the amorphous material. For example, carbon can improve the hardness and wear resistance of amorphous materials, phosphorus and sulfur may affect the processing performance and toughness of the materials, while aluminum, manganese, and copper can adjust the physical properties of amorphous materials, such as electrical conductivity and thermal conductivity. Iron-based amorphous materials with the above-mentioned components and contents possess excellent mechanical properties, corrosion resistance, and magnetic properties to meet the specific needs of cookware. It should be noted that the iron-based amorphous material according to this application can form a uniform and stable cookware coating after subsequent nitriding and oxidation treatments, ensuring the color uniformity of the cookware during use.

[0054] More specifically, the processing of natural ilmenite can include:

[0055] Crushing: Natural ilmenite is crushed using crushing equipment to reduce its particle size, making it easier for subsequent processing.

[0056] The combined gravity-magnetic-flotation process involves classifying the ground ilmenite, using gravity separation to remove gangue (silicon oxide, calcium carbonate, etc.), using magnetic separation to remove ferric oxide, and finally using flotation to remove silicon oxide, calcium carbonate, ferric oxide, and other impurities that remain after gravity and magnetic separation, ultimately yielding a high-purity ore whose main components are titanium oxide and ferrous oxide.

[0057] Grinding: Titanium concentrate is obtained by ball milling, drying, shaping, roasting and cooling. The titanium concentrate contains 60% to 85% iron oxides, 15% to 40% titanium oxides and the balance impurities.

[0058] Reduction method: The principle of preparing iron-based amorphous materials by thermal reduction is as follows:

[0059] The reaction between aluminum and titanium dioxide: Under high temperature conditions, aluminum (the reducing agent) reacts with xTiO2·yFeO (the main component of titanium concentrate). Specifically, the reaction process can be understood as follows: TiO2 + 3Al → Al2O3 + 2Ti; 2Al + 3FeO → 3Fe + Al2O3. Since xTiO2·yFeO in titanium concentrate is chelated together, and at high temperatures, Fe and Ti in the concentrate are randomly distributed and have a hematite structure (i.e., corundum-type structure), during the reduction reaction, titanium and iron are generated simultaneously and also chelated. Under high temperature conditions, the disordered distribution of Fe and Ti is retained, ultimately forming an iron-based amorphous material with iron and titanium as the main components.

[0060] In addition, the processing of natural ilmenite also includes the step of removing alumina. Specifically, the alumina generated in the above reaction needs to be removed to ensure the quality of the prepared iron-based amorphous material. As an example, acid washing can be used to remove the generated alumina. Specifically, the iron-titanium amorphous alloy containing alumina is first immersed in hydrochloric acid with a mass fraction of 10.7% at 50°C for 2 hours to remove the alumina. Then, it is washed with water to obtain a pure iron-based amorphous material.

[0061] According to this application, the volume percentage of the amorphous phase in the iron-based amorphous material is in the range of 55%-70%, and correspondingly, the volume percentage of the amorphous phase in the amorphous material layer 20 is also in the range of 55%-70%. Thus, the amorphous material layer 20 has low surface energy and excellent wear resistance and hardness, which can provide protection for the outer oxide treatment layer 40. In addition, even if the cookware is worn down to this layer during use, it can still maintain good non-stick properties. Furthermore, the amorphous material layer 20 has good corrosion resistance and can prevent corrosive media from corroding the substrate.

[0062] The iron-based self-fluxing alloy according to this application will be described in detail below.

[0063] In some embodiments, the amorphous material is a mixture of iron-based amorphous material and iron-based self-fluxing alloy. The iron-based amorphous material is the same as or similar to the iron-based amorphous material already described above. The main components of the iron-based self-fluxing alloy include C: 0.5%-0.6%, Si: 2%-3.5%, B: 1%-2%, Cr: 12%-14%, Ni: 28%-34%, and the balance Fe. In a preferred embodiment, the main components of the iron-based self-fluxing alloy include C: 0.55%, Si: 3%, B: 1.5%, Cr: 13%, Ni: 30%, and the balance Fe. C can improve the hardness and strength of the iron-based self-fluxing alloy, but excessive carbon may increase the alloy's brittleness. Therefore, the C content is controlled within the range of 0.5% to 0.6% to ensure hardness while avoiding the influence of brittleness. A silicon content ranging from 2% to 3.5% improves the alloy's fluidity and wettability, facilitating a good bond between the iron-based self-fluxing alloy and the iron-based amorphous material during melting. Silicon also enhances the alloy's corrosion resistance and oxidation resistance. A boron content ranging from 1% to 2% refines the grain structure of the iron-based self-fluxing alloy, improving its strength and toughness. Furthermore, boron improves the alloy's wear resistance and corrosion resistance. A chromium content ranging from 12% to 14% forms a dense oxide film, protecting the alloy from corrosion. Chromium also improves the alloy's hardness and wear resistance. A nickel content ranging from 28% to 34% improves the strength and toughness of the iron-based self-fluxing alloy while lowering its brittle transition temperature. Nickel also improves the alloy's machinability and weldability. Finally, the balance is iron. Iron is the main component of the iron-based self-fluxing alloy, ensuring its fundamental mechanical properties. Iron-based self-fluxing alloys with the above chemical composition and content possess high strength, high hardness, good corrosion resistance, and wettability. They can form a good bond with iron-based amorphous materials, further improving the performance and service life of cookware.

[0064] In some embodiments, the amorphous material is a mixture of iron-based amorphous material and iron-based self-fluxing alloy. Based on a total weight of 100% for the amorphous material, the iron-based amorphous material accounts for 95%-98% of the total weight of the amorphous material, with the balance being the iron-based self-fluxing alloy. Using a mixture of iron-based amorphous material and iron-based self-fluxing alloy as the amorphous material allows for good bonding with the amorphous material due to the excellent wettability and self-fluxing properties of the iron-based self-fluxing alloy. This results in an amorphous material with excellent corrosion resistance and hardness, thus ensuring the wear resistance and corrosion resistance of the amorphous material layer in the cookware.

[0065] Nitriding layer 30

[0066] According to this application, the nitriding layer 30 is formed by nitriding an amorphous coating. As an example, the amorphous coating is a layer formed of amorphous material. After nitriding, a first nitrided region 31 and a second nitrided region 32 are formed, constituting the nitriding layer 30. The first nitrided region includes a mixed layer of amorphous material and a first nitride, wherein the first nitride is a solid solution of the amorphous material and nitrogen. Exemplarily, based on the total weight of the first nitrided region being 100%, the weight percentage of the amorphous material is 50%-80%, with the remainder being the first nitride. The second nitrided region includes a mixed layer of cookware substrate material and a second nitride, wherein the second nitride is a solid solution of the cookware substrate material and nitrogen. Exemplarily, based on the total weight of the second nitrided region being 100%, the weight percentage of the cookware substrate material is 60%-90%, with the remainder being the second nitride.

[0067] According to this application, the surface of the first nitrided region 31 has an uneven structure, and the oxide treatment layer 40 is formed on the surface of the first nitrided region 31, with 50%-70% of the oxide treatment layer 40 located in the depressions of the uneven structure. Thus, the dense and high-hardness first nitrided region 31 can provide effective protection for the oxide treatment layer 40, preventing damage to the non-stick coating surface from hard parts such as shovels.

[0068] In some embodiments, the second nitrided region 32 includes a plurality of sublayers dispersed on the surface of the cookware substrate 10, and the first nitrided region 31 includes a main body and a protrusion formed on the bottom surface of the main body, wherein the protrusion passes through the amorphous material layer 20 and is connected to the second nitrided region 32.

[0069] In these embodiments, the protrusions on the surface of the main body forming the first nitrided region 31 serve as connecting bridges, tightly connecting the cookware substrate 10 with the amorphous material layer 20 and the first nitrided region 31, forming a continuous and stable structure. This enhances the adhesion between the non-stick coating and the cookware substrate, making the entire coating more robust and durable. Simultaneously, due to the presence of the sublayer, the non-stick coating can better disperse and alleviate stress when subjected to external forces or temperature changes, reducing the possibility of coating cracking or peeling.

[0070] In some embodiments, a chemical bond is formed at the junction of the second nitrided region 32 and the cookware substrate 10. It is understood that during the manufacturing process of the cookware, a chemical reaction occurs between nitrogen atoms and the cookware substrate material to form a stable nitride structure. This allows the cookware to withstand higher stress and temperature changes, thereby improving the overall structural strength and stability of the cookware.

[0071] According to this application, the first nitrided region, serving as an intermediate layer between the amorphous material layer and the oxide treatment layer, primarily enhances the coating's hardness and wear resistance. Its thicker structure more effectively resists scratches from cooking utensils and wear on the bottom of pots, thereby extending the lifespan of the non-stick coating. The second nitrided region, located between the first nitrided region and the cookware substrate, ensures a strong bond between the coating and the cookware substrate. This layer not only enhances the overall structural stability of the coating but also helps prevent peeling or blistering during use. In some embodiments, the thickness of the first nitrided region is 15μm-70μm, and the thickness of the second nitrided region is 2μm-10μm. If the thickness is too small, it cannot meet the stress and temperature change requirements of the cookware; if the thickness is too large, the performance is excessive, resulting in wasted manufacturing costs.

[0072] Oxidation treatment layer 40

[0073] According to this application, the oxide layer 40 is formed by oxidizing the first nitrided region 31. As an example, the first nitrided region comprises a mixed layer of amorphous material and a first nitride. After oxidation, the resulting oxide layer 40 is a mixed layer of amorphous material and oleophilic oxide. It should be noted that in this process, oxygen atoms are generally more reactive than nitrogen atoms and react more readily with metals. Therefore, the oxidation reaction takes precedence over the stable existence of the nitride, causing the iron nitride in the surface layer of the first nitrided region 31 to be gradually consumed by the oxidation reaction, forming a mixed layer of amorphous material and oleophilic oxide. The iron nitride in the surface layer of the first nitrided region 31 reacts with water vapor at high temperature to produce iron(III) oxide and ammonia. Titanium nitride reacts with water vapor at high temperature to generate titanium oxide, ammonia, and hydrogen.

[0074] Specifically, the oxidation treatment layer 40 is an oleophilic oxide layer, which is a mixed layer of alternating iron oxide particles and titanium oxide particles. Based on the total weight of the oleophilic oxide layer as 100%, iron oxide accounts for 70-90% of the weight, and titanium oxide accounts for 10-30% of the weight. All of these oxides are oleophilic, thus forming an oil film on the cookware surface, which is beneficial for a non-stick effect.

[0075] In some embodiments, the oxide layer has a low surface energy, for example, the surface energy of the oxide layer is 30 to 50 dynes. Such a low surface energy oxide layer, as the surface layer of the cookware, helps to maintain the non-stick properties of the cookware.

[0076] According to this application, the oxide treatment layer serves as the surface layer of the non-stick coating, and an oxide treatment layer of appropriate thickness can ensure the non-stick performance of the cookware. In some embodiments, the thickness of the oxide treatment layer is 1μm-3μm, which mainly provides the initial non-stick function. When the thickness of the oxide treatment layer is less than 1μm, the initial non-stick performance will fail too quickly. When the thickness of the oxide treatment layer is greater than 3μm, as the oxidation depth increases, the reaction time between the surface of the first nitrided region and oxygen will also increase accordingly. This may lead to uneven oxide film formation rate, and such unevenness may cause the oxide film structure to become loose.

[0077] According to a second aspect of this application, a method for manufacturing a cooker is provided, wherein the method for manufacturing a cooker includes:

[0078] Step S101: An amorphous coating with a preset rough surface is formed on the cookware substrate by thermal spraying of an amorphous material.

[0079] Step S102: Nitriding is performed on the cookware substrate with the amorphous coating, so that nitrogen atoms form a first nitriding region with the amorphous coating and a second nitriding region with the cookware substrate. The first nitriding region is located on the outer layer of the amorphous coating, and the second nitriding region is located on the inner side of the first nitriding region and extends from the bottom of the first nitriding region to the cookware substrate.

[0080] Step S103: The first nitrided region is oxidized to form an oxide treatment layer on the surface of the first nitrided region, thereby manufacturing a cookware. The first nitrided region includes a mixed layer of amorphous material and a first nitride, and the second nitrided region includes a mixed layer of cookware substrate material and a second nitride. The oxide treatment layer is an oleophilic oxide layer and serves as the surface layer of the non-stick coating of the cookware.

[0081] It should be noted that the non-stick coating includes an amorphous material layer 20, a first nitrided region 31 stacked on the outside of the amorphous material layer 20, and an oxide treatment layer 40 stacked on the outside of the first nitrided region 31. The non-stick coating also includes a second nitrided region 32 extending from the bottom of the first nitrided region onto the cookware substrate 10. The amorphous material layer 20 is the unnitrided portion of the amorphous coating formed by thermal spraying of amorphous material. The first nitrided region 31 is the product of nitrogen atoms combining with the amorphous material layer 20, and the oxide treatment layer 40 is the product of the first nitrided region combining with oxygen atoms.

[0082] The method for manufacturing a cooker according to this application will be described below with reference to specific embodiments.

[0083] Provide cookware base

[0084] According to this application, the cookware substrate 10 can be made of commonly used materials. Exemplarily, the material can be stainless steel, titanium, aluminum, their corresponding alloys, and composite materials. As an example, the cookware substrate 10 includes any one of an iron substrate, a magnesium substrate, a copper alloy substrate, an aluminum substrate, a stainless steel substrate, a titanium substrate, and a composite substrate formed from the above substrates. It is understood that the method for manufacturing cookware according to this application is adaptable to a variety of cookware substrates, allowing the manufacturing method to be free from limitations on a single substrate material, bringing greater convenience to cookware manufacturing. For example, different substrate materials can be combined to create novel cookware with unique properties, achieving complementary advantages of different material properties and improving the overall performance of the cookware.

[0085] According to this application, the cookware base 10 may have a shape corresponding to the function of the cookware. For example, such as... Figure 1 As shown, when the non-stick cookware is a non-stick pan, the cookware base 10 can have a conventional pan shape. It should be understood that... Figure 1 The nonstick pan is shown only as an example of the main body and other parts are not shown. The nonstick pan according to the present invention may also include common cookware structures / components such as handles (e.g., pot handles).

[0086] According to this application, the cookware substrate 10 can be a substrate that has undergone surface alkaline washing to remove oil, drying, and sandblasting treatment, and the substrate surface has a certain roughness. In an exemplary embodiment, the roughness of the substrate surface is in the range of Ra value between 4 μm and 6 μm.

[0087] Provide amorphous materials

[0088] According to this application, the amorphous material is the amorphous material described in the above embodiments.

[0089] In some embodiments, the amorphous material is in particulate form, and the particle size of the amorphous material is in the range of 30 μm to 70 μm. It should be noted that the amorphous material here is an iron-based amorphous material, or a mixture of an iron-based amorphous material and an iron-based self-fluxing alloy. As an example, both the iron-based self-fluxing alloy and the iron-based amorphous material are in the range of 30 μm to 70 μm, thereby making the particle size of the amorphous material in the range of 30 μm to 70 μm.

[0090] In these embodiments, amorphous materials with an average particle size in the range of 30 μm to 70 μm can form an amorphous coating with a predetermined rough surface. Specifically, when the particle size of the amorphous material is less than 30 μm, it is easy to cause molten droplets in the formed thermal spray coating, resulting in a poor appearance. When the particle size is greater than 70 μm, the surface roughness of the formed thermal spray coating is large, resulting in a poor final appearance. In addition, amorphous materials in the range of 30 μm to 70 μm can better contact and bond with the cookware substrate surface. At the same time, the interlocking effect between particles can also improve the cohesive strength of the amorphous coating, making the amorphous coating more robust and reliable. Furthermore, amorphous materials in the range of 30 μm to 70 μm have good flowability and filling properties, which can form a more uniform and dense amorphous coating during the spraying process, effectively reducing voids and defects in the amorphous coating.

[0091] Forming an amorphous coating

[0092] According to this application, an amorphous coating is formed by thermally spraying an amorphous material layer onto the inner surface of a substrate. According to this application, the amorphous coating can at least partially cover the inner surface of the substrate; in other words, the amorphous coating can cover a portion or all of the inner surface of the substrate. The amorphous coating is formed by thermally spraying the amorphous material provided in the embodiments of this application, thereby possessing non-stick properties and improved hardness.

[0093] According to some embodiments of this application, the amorphous phase volume ratio of the amorphous material can be 55%-70%. Thermal spraying of the amorphous material can retain its amorphous nature to form an amorphous coating with a certain amorphous phase volume ratio. Specifically, during the thermal spraying process, only the surface of the amorphous material is micro-melted, causing the individual particles to connect with each other, thereby forming an amorphous coating with an amorphous phase volume ratio of 55%-80%.

[0094] In an exemplary embodiment, thermal spraying specifically refers to plasma spraying. The process parameters for plasma spraying can be: current 500A-600A; voltage 50V-70V; argon flow rate 1000L / h-2000L / h; hydrogen flow rate 50L / h-70L / h; powder feeding gas flow rate 20L / h-50L / h; powder feeding speed 20g / min-40g / min; spraying distance 15cm-30cm; spraying angle 50°-70°; substrate temperature 25℃-35℃.

[0095] According to this application, by controlling the particle size of the amorphous material and the spraying parameters, an amorphous coating with a predetermined pore structure can be formed. The surface of the amorphous coating is relatively dense. When a thermal spraying process is performed on the amorphous material within the aforementioned process parameter range, the amorphous material powder can be fully melted, forming an amorphous coating of suitable thickness on the substrate surface, possessing both amorphous properties and porosity. For example, the thickness of the formed amorphous coating can be 20 μm-70 μm. For example, the formed amorphous coating has a surface pore structure suitable for reaction with fluorosilane materials or with a silane coupling agent. As an example, the coating has high density, and the pores are small and few to the naked eye; specifically, the porosity of the pore structure can be 2% to 5%, and the pore size is 0.2 μm to 2 μm. Under certain spraying parameters, the amorphous coating formed from the amorphous material has properties similar to those of the amorphous material itself, such as similar amorphous properties, a certain degree of non-stickiness, and hardness.

[0096] According to other embodiments of this application, the amorphous material powder itself has a certain degree of amorphousness, for example, it can be 55%-70%. By using amorphous material powder and controlling the surface temperature of the cookware substrate during the spraying process, an amorphous coating with an amorphous phase volume ratio in the range of 60%-95% can be formed, which can improve the amorphous phase ratio by 5%-25% compared to the aforementioned embodiments. This is determined by the chemical composition / content of the amorphous material itself and the cooling rate of the coating during the spraying process. Therefore, an amorphous coating with a higher degree of amorphization can be formed after spraying.

[0097] According to this application, the substrate includes a first surface and a second surface facing away from each other. The step of controlling the surface temperature of the substrate during the spraying process includes: cooling the second surface of the substrate, and spraying an amorphous material onto the first surface of the substrate, thereby forming an amorphous coating with a preset amorphous phase volume ratio on the first surface of the substrate. Specifically, the step of cooling the second surface of the substrate includes applying cold air to the second surface of the substrate and controlling the temperature of the cold air at -5 to 0°C. Then, the amorphous material is sprayed onto the first surface of the substrate. The amorphous coating thus formed has a relatively increased amorphous phase volume ratio. In an exemplary embodiment, the amorphous phase volume ratio in the amorphous coating is 60%-95%, which can increase it by 5%-25%. This allows the surface of the cookware that contacts the food to have a low surface energy, thereby providing better non-stick properties. It should be noted that the first surface can be an inner surface, and the second surface can be an outer surface. Of course, this application does not impose excessive limitations on this. It is understood that those skilled in the art, under the guidance of this application, can make the first surface an outer surface and the second surface an inner surface according to actual usage needs. In an exemplary embodiment, cooling the second surface of the substrate includes placing the second surface of the substrate in an environment of cooling gas. As an example, the cooling gas temperature is -15°C to 5°C, and the cooling gas flow rate is 2000L / h to 4000L / h.

[0098] The amorphous coating with an amorphous structure conceived according to the present invention can retain various properties of the aforementioned amorphous materials, and can exhibit properties superior to those of amorphous materials, such as, but not limited to, non-stickiness and hardness, under the control of the surface temperature of the cookware during the spraying process.

[0099] It should be noted that when the cookware substrate is iron or stainless steel, and the amorphous material comprises 55% to 85% iron, 10% to 40% titanium, and the balance being impurities, including at least one of carbon, phosphorus, sulfur, aluminum, manganese, and copper, the similarity in chemical composition between the cookware substrate and the amorphous material allows the amorphous material to fuse well with the substrate surface during the thermal spraying process when the amorphous material is sprayed onto the cookware substrate to form an amorphous coating. This ensures the bonding strength between the amorphous coating and the cookware substrate, making it less prone to coating peeling or detachment during use.

[0100] According to this application, the amorphous coating has a pre-defined rough surface. As an example, the surface roughness of the amorphous coating is 20 μm-50 μm. When the surface roughness of the amorphous coating is less than 30 μm, the roughness is too small, and the protective protrusions are not obvious, making the oxide layer easily worn. When the surface roughness of the amorphous coating is 50 μm, the final appearance roughness is too large, resulting in a poor appearance.

[0101] Nitriding

[0102] According to this application, a predetermined lattice spacing is provided within the amorphous coating, thus enabling the formation of a corresponding solid solution structure during subsequent nitriding and oxidation processes. Specifically, a cookware substrate with an amorphous coating is nitrided, causing nitrogen atoms to form a first nitrided region with the amorphous coating and a second nitrided region with the cookware substrate. The first nitrided region is located outside the second nitrided region and includes a mixed layer of amorphous material and a first nitride, wherein the first nitride is a solid solution of the amorphous material and nitrogen. The second nitrided region includes a mixed layer of cookware substrate material and a second nitride, wherein the second nitride is a solid solution of the cookware substrate material and nitrogen.

[0103] According to this application, the nitrided regions obtained by nitriding the cookware substrate with an amorphous coating can fill the pores of the amorphous coating, reduce the possibility of corrosive media entering between the cookware substrate 10 and the amorphous material layer 20, and ensure corrosion resistance.

[0104] According to this application, during the nitriding process, the nitriding temperature, nitriding time, and N content in the nitriding furnace (controlled by the concentration of ammonia) jointly determine the degree of nitriding of the cookware substrate with an amorphous coating. That is, they affect the nitriding depth, thus affecting the performance (durability, corrosion resistance) of the cookware substrate. Using ammonia (NH3) as the nitriding atmosphere is advantageous due to its high reactivity, ease of control, and good permeability. These characteristics make ammonia an ideal nitrogen source during the nitriding process. The main role of temperature is to decompose ammonia into N and H. As the temperature increases, the decomposition rate of ammonia accelerates, thereby providing more N atoms. Furthermore, high temperatures promote the diffusion of N atoms in the amorphous coating, causing them to react with elements in the coating (such as iron, titanium, etc.) to form nitrides. The nitriding time determines the depth of N atom penetration. A suitable nitriding time ensures appropriate nitriding penetration depth while maintaining coating performance. It's important to note that longer nitriding time isn't always better. Excessive time can lead to over-nitriding of the coating, affecting its performance. The concentration of ammonia gas determines the nitrogen (N) content in the nitriding furnace. Higher ammonia concentrations result in more nitrogen atoms in the furnace, leading to faster penetration into the amorphous coating. However, excessively high concentrations can cause excessive nitride formation on the coating surface, affecting its uniformity and performance.

[0105] In an exemplary embodiment, nitriding the cookware substrate with the amorphous coating includes: placing the cookware substrate with the amorphous coating in a nitriding furnace, which is a device for nitriding treatment capable of providing a stable temperature and atmosphere environment. Ammonia gas is introduced so that the volume percentage of ammonia in the nitriding furnace is not less than 90%. Ammonia, as a gas in the nitriding treatment, can react with the metal surface at high temperatures to form nitrides. A high concentration of ammonia helps accelerate the nitriding process and improve the nitriding effect. The furnace pressure is 1–1.2 atmospheres, and the furnace temperature is adjusted to 130°C–150°C to activate the atoms on the surface of the cookware substrate and the amorphous coating, preparing for the subsequent nitriding reaction. Next, adjust the ammonia flow rate to 700 L / h to 1000 L / h, then adjust the furnace temperature to 530℃ to 580℃ and hold for 3 to 7 hours. Under these high temperature and high-speed ammonia flow conditions, the nitriding reaction will proceed rapidly, and nitrogen atoms will form corresponding nitrided regions with the amorphous coating and cookware substrate. Holding for 3 to 7 hours ensures that the nitriding reaction is fully completed to form a nitrided layer of the predetermined depth and uniformity. After the nitrided layer is formed, adjust the ammonia flow rate to 300 L / h to 500 L / h, and lower the furnace temperature at a rate of 2℃ / min to 4℃ / min. This cooling process helps stabilize the structure of the nitrided layer, allowing it to gradually cool to room temperature to avoid stress or cracks caused by rapid cooling. Finally, stop the ammonia flow after the furnace temperature drops to 50℃. Under the influence of the above parameters, because the surface of the amorphous coating has a predetermined rough structure, during nitriding, the troughs of the rough structure will be nitrided onto the cookware substrate. That is, the nitriding layer 30 according to this application will appear in different regions, for example, it may include a first nitriding region 31 and a second nitriding region 32. The first nitriding region 31 includes a mixed layer of amorphous material and a first nitride, and the second nitriding region 32 includes a mixed layer of cookware substrate material and a second nitride. As an example, the thickness of the first nitriding region is 15μm-70μm, and the thickness of the second nitriding region is 2μm-10μm.

[0106] In these embodiments, the above nitriding treatment can form nitrided regions with excellent properties. These nitrided regions not only improve the hardness and wear resistance of the cookware, but also enhance its corrosion resistance and non-stick properties, providing a good foundation for subsequent oxidation treatment and use.

[0107] Oxidation

[0108] According to this application, after nitriding, oxidation is performed on the surface of the formed first nitrided region 31 so that the surface of the first nitrided region 31 reacts and forms an oxide treatment layer 40.

[0109] According to this application, during the oxidation process, the oxygen content, oxidation temperature, and oxidation time settings in the oxidation furnace determine the degree of oxidation of the cookware substrate with an amorphous coating, i.e., affect the oxidation depth, and thus the performance (durability, corrosion resistance) of the cookware substrate. Water vapor is used as the oxidation atmosphere, providing the necessary oxygen atoms to promote the oxidation reaction. Compared to some other oxidants, water vapor does not produce harmful substances during the reaction, is stable, and is environmentally friendly. The concentration of water vapor is also an important parameter, directly determining the rate and extent of the oxidation reaction. The concentration of water vapor is usually determined by the input water flow rate; a higher water flow rate results in a higher water vapor concentration and a denser oxide film. However, it should be noted that the water flow rate cannot be increased indefinitely; beyond a certain range, the density of the oxide film will no longer significantly increase. Furthermore, appropriate oxidation temperature and time ensure that the water vapor reacts with elements such as iron and titanium in the first nitriding region, thereby generating a uniform and dense oxide film. Too short an oxidation temperature / time may result in an incomplete oxidation reaction, while too long an oxidation temperature / time may trigger unnecessary side reactions or lead to a decrease in cookware performance.

[0110] In some exemplary embodiments, the step of oxidizing the first nitrided region includes: placing a cookware substrate having the first nitrided region in an oxidation furnace, the oxidation furnace being a device for oxidation treatment capable of providing a stable temperature and atmosphere environment. The furnace temperature is adjusted to 420°C to 540°C to activate the atoms on the surface of the first nitrided region, preparing it for subsequent oxidation reactions. Distilled water is continuously introduced into the oxidation furnace at a flow rate of 10 g / s to 15 g / s for 0.5 h to 6 h, where the distilled water reacts with the first nitrided region at high temperature to form an oxide layer. The flow rate and duration of the distilled water ensure the formation of a predetermined depth and uniform oxide layer. After the oxide layer is formed, the distilled water supply is stopped, and the furnace temperature is reduced to 50°C at a cooling rate of 2°C / min to 4°C / min to help stabilize the structure of the oxide layer. The oxide layer is then gradually cooled to room temperature to avoid stress or cracking caused by rapid cooling.

[0111] In these embodiments, the above oxidation treatment can form an oxide layer with excellent properties. This oxide layer not only improves the non-stick properties of the cookware but also enhances its corrosion resistance and wear resistance, providing excellent protection for the cookware's use. Furthermore, the oxide layer is typically dark in color, ensuring the cookware's aesthetic appearance.

[0112] Sealing

[0113] According to this application, the surface of the non-stick coating has a porous structure capable of storing oil, and the porous structure can be filled with grease or silicone oil. A sealing layer can also be provided outside the non-stick coating to further enhance the initial non-stick properties. Specifically, after forming the non-stick coating, the method of manufacturing the cookware further includes filling the non-stick coating with grease or silicone oil to form a surface seal, thereby ensuring the non-stick and corrosion-resistant properties of the cookware coating.

[0114] In some embodiments, the step of filling the non-stick coating with silicone oil to form a surface seal includes applying silicone oil to the surface of the non-stick coating, allowing it to penetrate into the surface pores of the non-stick coating, and sintering at a first predetermined temperature for a first predetermined time, thereby forming a surface seal in the non-stick coating. In an exemplary embodiment, the silicone oil may be polydimethyl silicone oil. After coating, the cookware coated with polydimethyl silicone oil can be placed in a sintering furnace for curing, wherein the first predetermined curing temperature is 300°C-400°C, and the first predetermined curing time is 3-10 minutes.

[0115] In some embodiments, the step of filling the non-stick coating with grease to form a surface seal includes immersing the non-stick coating in grease at a second predetermined temperature for a second predetermined time, allowing the grease to penetrate the surface pores of the non-stick coating, thereby forming a surface seal. In an exemplary embodiment, the grease may include edible oil (peanut oil, rapeseed oil) or palm oil, heating the edible oil or palm oil to a second predetermined temperature and maintaining it for a second predetermined time to form a sealing layer on the non-stick coating, wherein the second predetermined temperature is 80°C-100°C and the second predetermined time is 10-30 minutes.

[0116] According to this application, by filling with grease or silicone oil, a surface seal is formed on the non-stick coating, making the surface of the non-stick coating hydrophobic due to the presence of an oil film. This ensures the non-stick properties of the cookware. For example, before silicone oil treatment, the non-stick coating may have a surface energy of 30 to 50 dynes. Although this is lower than the surface energy of fluoropolymer non-stick coatings (18 to 25 dynes), after grease or silicone oil treatment, the surface energy can be reduced to 10 to 25 dynes, thus achieving non-stick performance comparable to or even better than fluoropolymer non-stick coatings. Silicone oil is better than grease in optimizing non-stick properties. Furthermore, it prevents corrosive media from entering, thus improving corrosion resistance.

[0117] The present application will now be described in detail with reference to specific embodiments, but the scope of protection of the present application is not limited to the embodiments.

[0118] Example 1

[0119] The cookware according to Example 1 is manufactured by the following method.

[0120] Step S10: Prepare the cookware base. Specifically, the stainless steel sheet is deep-drawn into shape, then surface-washed with alkali to remove oil, dried, and sandblasted to obtain a cookware base with a thickness of 1.5cm.

[0121] Step S20: Prepare an amorphous material with an average particle size of 40 μm. The chemical composition of the amorphous material includes 85% iron, 15% titanium, and the balance impurities (carbon, phosphorus, sulfur, aluminum, manganese, and copper).

[0122] Step S30: Spray a non-stick material onto the cookware substrate. Specifically, 400-mesh amorphous material powder is loaded into a powder feeder, with the following parameters set: current 300A; voltage 60V; argon flow rate 1500L / h; hydrogen flow rate 60L / h; powder feeding gas flow rate 30L / h; powder feeding speed 30g / min; spraying distance 20cm; spraying angle 60°; substrate temperature 30℃. The non-stick material powder is then sprayed onto the inner surface of the substrate to obtain an amorphous coating with a maximum thickness of 70μm and a surface roughness of 30μm.

[0123] Step S40: Nitriding is performed on the cookware substrate with the amorphous coating. Specifically, the cookware substrate with the amorphous coating is placed in a nitriding furnace, and ammonia gas is introduced so that the volume ratio of ammonia gas in the nitriding furnace is not less than 90%, the furnace pressure is 1.1 atmospheres, and the furnace temperature is adjusted to 140°C. Then, the ammonia gas flow rate is adjusted to 900 L / h, and the furnace temperature is adjusted to 560°C and held for 6 hours. Finally, the ammonia gas flow rate is adjusted to 400 L / h, and the furnace temperature is reduced to room temperature at a cooling rate of 3°C / min. Under these conditions, a nitrided layer is obtained. The nitrided layer includes a first nitrided region and a second nitrided region. The first nitrided region is located on the outer layer of the amorphous coating, and the second nitrided region is located on the inner side of the first nitrided region and extends from the bottom of the first nitrided region to the cookware substrate. The maximum thickness of the first nitrided region is 46 μm, and the average thickness of the second nitrided region is 6 μm.

[0124] Step S50: Oxidize the first nitrided region. Specifically, place the cookware substrate with the first nitrided region in an oxygen infiltration furnace and adjust the furnace temperature to 450°C. Continuously introduce distilled water into the oxygen infiltration furnace at a flow rate of 10 g / s for 3 hours. Then, reduce the furnace temperature to room temperature at a cooling rate of 3°C / min to complete the manufacture of the cookware of Example 1.

[0125] Example 2

[0126] In step S20, except that an amorphous material with an average particle size of 30 μm is used to replace the amorphous material of Example 1, the cookware of Example 2 is manufactured using the same method as in Example 1.

[0127] Example 3

[0128] In step S20, except that an amorphous material with an average size of 70 μm is used to replace the amorphous material of Example 1, the cookware of Example 3 is manufactured using the same method as in Example 1.

[0129] Example 4

[0130] In step S20, except that a different material (the chemical composition of the amorphous material in this embodiment includes 80% iron, 15% titanium and the balance impurities) is used to replace the amorphous material of Example 1, the cookware of Example 4 is manufactured using the same method as in Example 1.

[0131] Example 5

[0132] In step S20, except that a different material (the chemical composition of the amorphous material in this embodiment includes 75% iron, 15% titanium and the balance impurities) is used to replace the amorphous material of Example 1, the cookware of Example 5 is manufactured using the same method as in Example 1.

[0133] Example 6

[0134] In step S20, except that a different material (the chemical composition of the amorphous material in this embodiment includes 75% iron, 20% titanium and the balance impurities) is used to replace the amorphous material of Example 1, the cookware of Example 6 is manufactured using the same method as in Example 1.

[0135] Example 7

[0136] In step S20, except that a different material (the chemical composition of the amorphous material in this embodiment includes 70% iron, 15% titanium and the balance impurities) is used to replace the amorphous material of Example 1, the cookware of Example 7 is manufactured using the same method as in Example 1.

[0137] Example 8

[0138] In step S20, except that a different material (the chemical composition of the amorphous material in this embodiment includes 70% iron, 20% titanium and the balance impurities) is used to replace the amorphous material of Example 1, the cookware of Example 8 is manufactured using the same method as in Example 1.

[0139] Example 9

[0140] In step S20, except that a different material (the chemical composition of the amorphous material in this embodiment includes 70% iron, 25% titanium and the balance impurities) is used to replace the amorphous material of Example 1, the cookware of Example 9 is manufactured using the same method as in Example 1.

[0141] Example 10

[0142] In step S20, except that a different material (the chemical composition of the amorphous material in this embodiment includes 65% iron, 15% titanium and the balance impurities) is used to replace the amorphous material of Example 1, the cookware of Example 10 is manufactured using the same method as in Example 1.

[0143] Example 11

[0144] In step S20, except that a different material (the chemical composition of the amorphous material in this embodiment includes 65% iron, 20% titanium and the balance impurities) is used to replace the amorphous material of Example 1, the cookware of Example 11 is manufactured using the same method as in Example 1.

[0145] Example 12

[0146] In step S20, except that a different material (the chemical composition of the amorphous material in this embodiment includes 65% iron, 25% titanium and the balance impurities) is used to replace the amorphous material of Example 1, the cookware of Example 12 is manufactured using the same method as in Example 1.

[0147] Example 13

[0148] In step S20, except that a different material (the chemical composition of the amorphous material in this embodiment includes 65% iron, 30% titanium and the balance impurities) is used to replace the amorphous material of Example 1, the cookware of Example 13 is manufactured using the same method as in Example 1.

[0149] Example 14

[0150] In step S20, except that a different material (the chemical composition of the amorphous material in this embodiment includes 60% iron, 15% titanium and the balance impurities) is used to replace the amorphous material of Example 1, the cookware of Example 14 is manufactured using the same method as in Example 1.

[0151] Example 15

[0152] In step S20, except that a different material (the chemical composition of the amorphous material in this embodiment includes 60% iron, 20% titanium and the balance impurities) is used to replace the amorphous material of Example 1, the cookware of Example 15 is manufactured using the same method as in Example 1.

[0153] Example 16

[0154] In step S20, except that a different material (the chemical composition of the amorphous material in this embodiment includes 60% iron, 25% titanium and the balance impurities) is used to replace the amorphous material of Example 1, the cookware of Example 16 is manufactured using the same method as in Example 1.

[0155] Example 17

[0156] In step S20, except that a different material (the chemical composition of the amorphous material in this embodiment includes 60% iron, 30% titanium and the balance impurities) is used to replace the amorphous material of Example 1, the cookware of Example 17 is manufactured using the same method as in Example 1.

[0157] Example 18

[0158] In step S20, except that a different material (the chemical composition of the amorphous material in this embodiment includes 60% iron, 35% titanium and the balance impurities) is used to replace the amorphous material of Example 1, the cookware of Example 18 is manufactured using the same method as in Example 1.

[0159] Example 19

[0160] In step S20, except that a different material (the amorphous material in this embodiment is a mixture of iron-based amorphous material and iron-based self-fluxing alloy from Example 1, wherein the weight percentage of iron-based amorphous material is 97% and the weight percentage of iron-based self-fluxing alloy is 3%) is used to replace the amorphous material of Example 1, the cookware of Example 19 is manufactured using the same method as in Example 1.

[0161] Example 20

[0162] Except for step S30, in which the outer surface of the cookware substrate is placed in a circulating cooling air environment (the temperature of the cooling gas is -15°C) to prepare an amorphous coating, the cookware of Example 20 is manufactured using the same method as in Example 1.

[0163] Comparative Example 1

[0164] In step S20, except that a different material (the material in this comparative example is natural ilmenite, with the total weight of natural ilmenite being 100%, and the composition of natural ilmenite including 48% titanium oxide, 8% ferric oxide, 33% ferrous oxide, 5% magnesium oxide, and the balance being aluminum oxide, silicon oxide, and calcium carbonate) is used to replace the amorphous material of Example 1 and steps S40 and S50 are not performed, the cookware of Comparative Example 1 is manufactured using the same method as in Example 1.

[0165] Comparative Example 2

[0166] Except for replacing the amorphous material of Example 1 with a different material (the material of this comparative example is natural ilmenite, with the total weight of natural ilmenite being 100%, and the composition of natural ilmenite including 48% titanium oxide, 8% ferric oxide, 33% ferrous oxide, 5% magnesium oxide, and the balance being aluminum oxide, silicon oxide and calcium carbonate), the cookware of Comparative Example 2 was manufactured using the same method as in Example 1.

[0167] Comparative Example 3

[0168] In step S20, except that a different material (ferrous magnesium aluminum titanate in this comparative example) is used to replace the amorphous material of Example 1 and steps S40 and S50 are not performed, the cookware of Comparative Example 3 is manufactured using the same method as in Example 1.

[0169] Comparative Example 4

[0170] In step S20, except that a different material (ferrous magnesium aluminum titanate in this comparative example) was used to replace the amorphous material of Example 1, the cookware of Comparative Example 4 was manufactured using the same method as in Example 1.

[0171] Comparative Example 5

[0172] In step S20, except that a different material (the material in this comparative example is a high-entropy amorphous alloy FeCrWTiNi) is used to replace the amorphous material of Example 1 and steps S40 and S50 are not performed, the cookware of Comparative Example 5 is manufactured using the same method as in Example 1.

[0173] Comparative Example 6

[0174] In step S20, except that a different material (the material in this comparative example is a high-entropy amorphous alloy FeCrWTiNi) is used to replace the amorphous material of Example 1, the cookware of Comparative Example 6 is manufactured using the same method as in Example 1.

[0175] Comparative Example 7

[0176] Except for not performing step S40 (i.e., not performing nitriding), the cookware of Comparative Example 7 was manufactured using the same method as in Example 1.

[0177] Comparative Example 8

[0178] Except for not performing step S50 (i.e., not performing oxidation), the cookware of Comparative Example 8 was manufactured using the same method as in Example 1.

[0179] Test methods and evaluation criteria, test results

[0180] The coatings of the cookware obtained in Examples 1 to 20 and Comparative Examples 1 to 8 were subjected to performance tests, and the results are recorded in Table 1 below. The specific performance test methods are as follows:

[0181] I. Testing Methods and Evaluation Criteria

[0182] 1. Initial non-stick test method: GB / T32095.2-2015 test method for non-stick properties of fried eggs. This method is for initial non-stick properties and is divided into three levels: I, II and III. Level I has the best non-stick properties and Level III has the worst non-stick properties.

[0183] 2. Grade I durable non-stick test method: GB / T32388-2015 durable non-stick test method, the unit is the number of times. The higher the number of times, the longer the life. 500 times is used to evaluate the non-stick result once. The number of times is recorded until Grade II is reached.

[0184] 3. Level II durable non-stick test method: GB / T32388-2015 durable non-stick test method, the unit is the number of times. The higher the number of times, the longer the life. 500 times is used to evaluate the non-stick result once, and the number of times is recorded until the use reaches Level III.

[0185] 4. Corrosion resistance test method: Wash the cookware with neutral detergent; then add 1 / 3 of the cookware volume of a 5% NaCl solution (prepared with distilled water) to the cookware, heat it on a gas stove with an asbestos mesh, and keep it at a gentle boil after it boils (dilution water needs to be added continuously during the heating process to maintain the original concentration of the solution); observe the state of the cookware every 0.5 hours and record the time when rust appears inside the cookware.

[0186] 5. Adhesion test method: Use a 500g steel ball to drop from a certain height above the bottom plane of the sample. If no cracks are found, increase the height by 5cm for the next test. If cracks are found, this height is the adhesion height of the cookware coating.

[0187] 6. Hardness Testing and Evaluation Standards: The Vickers hardness test method is used to test the Vickers hardness of the cookware coating. The unit of hardness value is HV. For hardness testing, the higher the measured hardness value, the harder the sample. When the sample is a non-stick coating, the higher the hardness, the harder the non-stick coating, the stronger its resistance to abrasion from metal spatulas and food, and the less easily it is worn away, thus resulting in a longer service life. Generally speaking, it is expected that the hardness of the non-stick coating is not less than 600 HV.

[0188] II. Test Results

[0189] Table 1 Test Results

[0190]

[0191] As can be seen from Table 1, the cookware according to this application has excellent Class I and Class II durable non-stick properties, as well as good hardness, corrosion resistance and adhesion. Therefore, the cookware coating not only has excellent Class I and Class II durable non-stick properties, hardness and corrosion resistance, but also excellent adhesion. Therefore, the non-stick coating of the cookware is more durable.

[0192] Specifically, nitriding an amorphous coating can improve its hardness and adhesion, and subsequent oxidation can create a cookware surface with superior non-stick properties.

[0193] As can be seen from Examples 1, 2 and 3, the coating formed by non-stick materials with larger particle sizes has better Class II durable non-stick properties. This is because larger particle sizes can form suitable surface roughness structures, which can protect the surface oxide treatment layer and ensure more durable non-stick properties.

[0194] As can be seen from Examples 1 and 20, by controlling the spraying process (i.e., placing the outer surface of the cookware in a cooling gas environment during the plasma spraying process), the long-lasting non-stick performance can be improved to a certain extent.

[0195] The coating on cookware of the same proportions obviously cannot possess multiple properties such as excellent non-stick properties, scratch resistance, adhesion, and corrosion resistance. Therefore, the cookware is less durable.

[0196] While the invention has been specifically shown and described with reference to exemplary embodiments thereof, those skilled in the art will understand that various changes in form and detail may be made herein without departing from the spirit and scope of the invention as defined by the claims and their equivalents. The embodiments should be considered in a descriptive sense and not for limiting purposes only. Therefore, the scope of the invention is not defined by the specific embodiments thereof, but by the claims, and all differences within that scope will be construed as included in the invention.

[0197] While embodiments of this application have been described in detail above, those skilled in the art can make various modifications and variations to the embodiments of this application without departing from the spirit and scope of this application. However, it should be understood that, in the view of those skilled in the art, these modifications and variations will still fall within the spirit and scope of the embodiments of this application as defined in the claims.

[0198] While the invention has been specifically shown and described with reference to exemplary embodiments thereof, those skilled in the art will understand that various changes in form and detail may be made herein without departing from the spirit and scope of the invention as defined by the claims and their equivalents. The embodiments should be considered in a descriptive sense and not for limiting purposes only. Therefore, the scope of the invention is not defined by the specific embodiments thereof, but by the claims, and all differences within that scope will be construed as included in the invention.

Claims

1. A cooking utensil, characterized in that, The cookware includes a cookware substrate and a non-stick coating formed on the cookware substrate. The non-stick coating includes an amorphous material layer, a first nitrided region stacked on the outside of the amorphous material layer, and an oxide treatment layer stacked on the outside of the first nitrided region. The non-stick coating also includes a second nitrided region extending from the bottom of the first nitrided region to the cookware substrate. The amorphous material layer is formed of amorphous material. The first nitrided region includes a mixed layer of amorphous material and a first nitride. The second nitrided region includes a mixed layer of cookware substrate material and a second nitride. The oxide treatment layer is an oleophilic oxide layer and serves as the surface layer of the non-stick coating of the cookware.

2. The cookware according to claim 1, characterized in that, The thickness of the amorphous material layer is 2μm-10μm; and / or the thickness of the first nitrided region is 15μm-70μm; and / or the thickness of the second nitrided region is 2μm-10μm; and / or the thickness of the oxide treatment layer is 1μm-3μm.

3. The cookware according to claim 1, characterized in that, The surface energy of the oxidized layer is 30 to 50 dynes.

4. The cookware according to claim 1, characterized in that, The amorphous material is an iron-based amorphous material.

5. The cookware according to claim 1, characterized in that, The amorphous material is a mixture of iron-based amorphous material and iron-based self-fluxing alloy. Based on the total weight of the amorphous material being 100%, the weight percentage of the iron-based amorphous material is 95%-98%, and the remainder is iron-based self-fluxing alloy.

6. The cookware according to claim 5, characterized in that, The chemical composition of the iron-based self-fluxing alloy includes: C: 0.5%-0.6%, Si: 2%-3.5%, B: 1%-2%, Cr: 12%-14%, Ni: 28%-34%, and the balance Fe.

7. The cookware according to any one of claims 4 to 6, characterized in that, Based on the total weight of the iron-based amorphous material as 100%, the composition of the iron-based amorphous material includes 60% to 85% iron, 15% to 40% titanium, and the balance impurities, wherein the impurities include at least one of carbon, phosphorus, sulfur, aluminum, manganese, and copper.

8. The cookware according to any one of claims 1 to 6, characterized in that, The surface pores of the non-stick coating are filled with grease or silicone oil.

9. A method for manufacturing a cookware, characterized in that, The method for manufacturing the cookware includes: An amorphous coating with a predetermined rough surface is formed on the cookware substrate by thermal spraying of an amorphous material; The cookware substrate having the amorphous coating is nitrided such that nitrogen atoms form a first nitrided region with the amorphous coating and a second nitrided region with the cookware substrate, wherein the first nitrided region is located on the outer layer of the amorphous coating and the second nitrided region is located on the inner side of the first nitrided region and extends from the bottom of the first nitrided region to the cookware substrate; The first nitrided region is oxidized to form an oxide treatment layer on the surface of the first nitrided region, thereby manufacturing cookware; The first nitrided region includes a mixed layer of amorphous material and a first nitride, the second nitrided region includes a mixed layer of cookware substrate material and a second nitride, and the oxidation treatment layer is an oleophilic oxide layer, which serves as the surface layer of the non-stick coating of the cookware.

10. The method for manufacturing a cookware according to claim 9, characterized in that, The nitriding of the cookware substrate with the amorphous coating includes: placing the cookware substrate with the amorphous coating in a nitriding furnace, introducing ammonia gas so that the volume percentage of ammonia gas in the nitriding furnace is not less than 90%, and adjusting the furnace temperature to 130°C to 150°C; then adjusting the ammonia gas flow rate to 700L / h to 1000L / h, then adjusting the furnace temperature to 530°C to 580°C, holding the temperature for 3h to 7h, and finally adjusting the ammonia gas flow rate to 300L / h to 500L / h, and reducing the furnace temperature to room temperature at a cooling rate of 2°C / min to 4°C / min.

11. The method for manufacturing a cookware according to claim 9, characterized in that, The step of oxidizing the first nitrided region includes: placing the cookware substrate having the first nitrided region in an oxygen infiltration furnace, adjusting the furnace temperature to 420°C to 540°C; continuously introducing distilled water into the oxygen infiltration furnace at a flow rate of 10 g / s to 15 g / s for 0.5 h to 6 h, and then lowering the furnace temperature to room temperature at a cooling rate of 2°C / min to 4°C / min.

12. The method for manufacturing a cookware according to claim 9, characterized in that, The thickness of the amorphous coating is 20μm-70μm, the thickness of the oxide layer is 1μm-3μm, the thickness of the first nitrided region is less than or equal to the thickness of the amorphous coating, and the thickness of the second nitrided region is 2μm-10μm; and / or The cookware substrate includes any one of the following: iron substrate, magnesium substrate, copper alloy substrate, aluminum substrate, stainless steel substrate, titanium substrate, and composite substrate formed by the above substrates.

13. The method for manufacturing a cookware according to claim 9, characterized in that, The amorphous material is a granular material with an average particle size in the range of 30μm to 70μm.

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