CN114381681A

CN114381681A - Cooking utensil and preparation method thereof

Info

Publication number: CN114381681A
Application number: CN202011121110.5A
Authority: CN
Inventors: 潘广彬; 戴文俊
Original assignee: Zhejiang Futengbao Household Products Co ltd
Current assignee: Zhejiang Futengbao Household Products Co ltd
Priority date: 2020-10-19
Filing date: 2020-10-19
Publication date: 2022-04-22

Abstract

The invention provides a cooking appliance and a preparation method thereof, and relates to the technical field of cooking appliances. The cooking appliance includes: a substrate, wherein the material of the substrate comprises aluminum, aluminum alloy or aluminum composite material; an aluminum oxide layer disposed on a surface of the substrate; wherein the aluminum oxide layer is a thermal spray coating or a cold spray coating, and the aluminum oxide layer comprises alpha-Al₂O₃. The cooking utensil has the advantages of high surface hardness, good corrosion resistance, durable wear resistance, good non-adhesion and long service life.

Description

Cooking utensil and preparation method thereof

Technical Field

The invention relates to the technical field of cooking appliances, in particular to a cooking appliance and a preparation method thereof.

Background

In the traditional cooker and household appliance industries, in order to reduce the weight of products and meet the requirements of fast heating, uniform heat transfer and the like, aluminum or aluminum alloy materials are generally adopted to manufacture the base body of a cooking appliance. However, materials such as aluminum and aluminum alloys are prone to defects such as low hardness and poor wear resistance and corrosion resistance during use, and require surface treatment.

In the prior art, in order to improve the hardness and wear resistance of an aluminum or aluminum alloy base material, the base material is generally required to be oxidized to form aluminum oxide (Al)₂O₃) The film achieves the purpose of surface strengthening. However, the currently formed alumina film has more or less defects, such as that the hardness of the currently commonly used low-temperature sulfuric acid anodic oxidation technology is generally 350-450HV, the hardness of the formed alumina film is low, and the corrosion resistance and the wear resistance are still to be improved. With the continuous development of scientific technology or economy, the use requirements of users on cooking utensil products are continuously improved, and an alumina film layer formed by the existing low-temperature sulfuric acid anodic oxidation technology cannot meet the market requirements and the use expectation of customers. Therefore, research and development of a surface strengthening technology capable of achieving higher hardness and stronger corrosion resistance become a technical problem to be solved urgently in related industries at present.

Disclosure of Invention

The present invention is directed to a cooking utensil and a method for manufacturing the same, which has advantages of high surface hardness, good corrosion resistance, good wear resistance, etc., and can overcome the above problems or at least partially solve the above technical problems.

In order to achieve the purpose, the invention adopts the technical scheme that:

according to one aspect of the present invention, there is provided a cooking appliance, comprising:

a substrate, wherein the material of the substrate comprises aluminum, aluminum alloy or aluminum composite material;

an aluminum oxide layer disposed on a surface of the substrate;

wherein, theThe aluminum oxide layer is a thermal spray coating or a cold spray coating, and comprises alpha-Al₂O₃。

The cooking utensil forms alumina layers on the surfaces of different aluminum base materials by adopting a cold spraying or hot spraying mode, and the formed alumina layers comprise alpha-Al₂O₃Thereby realizing the effects of high hardness, strong corrosion resistance, low investment, low processing cost and high output. In detail, alpha-Al₂O₃Is the most stable phase in all aluminum oxides and has the characteristics of good formability, stable crystalline phase, high hardness, good structural stability and the like, so compared with an aluminum oxide film layer formed by common sulfuric acid anodic oxidation, the alpha-Al film formed by the method has the advantages of being good in formability, stable in crystalline phase, high in hardness, good in structural stability and the like₂O₃The film layer can obviously improve the hardness and the corrosion resistance of the film layer, and the alpha-Al₂O₃The wear resistance of the film layer is also better, which is beneficial to prolonging the service life of the coating. Meanwhile, the aluminum oxide layer is formed on the surfaces of different aluminum base materials by utilizing a cold spraying or hot spraying mode, and compared with the existing micro-arc oxidation mode, the cold spraying or hot spraying mode can reduce the equipment input cost, reduce the production cost, improve the efficiency and reduce the noise; the method can avoid the limitation of the prior sulfuric acid anodic oxidation and micro-arc oxidation modes on the silicon content in the matrix material, can realize the effects of strengthening the surface of the matrix material with higher silicon content and enhancing the corrosion resistance, and improves the comprehensive performance of the product. In addition, compared with the existing mode of thermally spraying metal or titanium-containing ceramic powder, the alpha-Al formed by the invention₂O₃The film layer can avoid potential corrosion and chlorine-philic corrosion and improve the corrosion resistance.

In one possible implementation, the material of the base body comprises cast aluminum, and the mass content of silicon in the cast aluminum is less than 15%;

or the mass content of silicon in the cast aluminum is 15-25%.

Compared with the existing sulfuric acid anodic oxidation and micro-arc oxidation modes, the purpose of strengthening the surface and increasing the corrosion resistance of cast aluminum (cast aluminum with silicon content of more than 15%) with high silicon content cannot be realized, and the popularization and application of the cast aluminum base material in the field of cookers are limited.

In one possible implementation, the raw material for forming the aluminum oxide layer includes α -Al₂O₃Powder or aluminium coated alpha-Al₂O₃The wire of (1).

When an alumina layer is formed on the surface of the substrate, aluminum-coated alpha-Al is adopted₂O₃Compared with powdery spraying raw materials, the spraying raw materials of the powder wire have higher utilization rate, and the aluminum-coated alpha-Al₂O₃The powder wire contains aluminum with a lower melting point, so that the wire has a lower melting point (generally about 640 ℃), and can reach a molten state in a short time in a spraying process, and the production efficiency can be improved. And because the aluminum is coated with alpha-Al₂O₃The powder wire has low melting point, so that the adhesion fastness can be improved without fluxing by a heating gas source (such as hydrogen, propane and the like) in the processing process, and the aluminum-coated alpha-Al is adopted₂O₃The powder wire can be combined with the aluminum base material more tightly under the condition of lower process operation requirement or lower process cost.

In one possible implementation, the thickness of the aluminum oxide layer is 30 μm to 120 μm. Within the thickness range, the method is beneficial to reducing the cost and ensuring the mechanical property, the corrosion resistance and the like of the alumina layer.

In one possible implementation, the cooking utensil further comprises an atomized spray coating layer, and the material of the atomized spray coating layer comprises at least one of fluorine-containing paint, silicone paint or ceramic paint.

According to another aspect of the present invention, there is provided a method of preparing a cooking appliance, comprising the steps of:

providing a substrate, wherein the material of the substrate comprises aluminum, aluminum alloy or aluminum composite material;

carrying out thermal spraying or cold spraying treatment on an aluminum oxide raw material to form an aluminum oxide layer on the surface of the substrate, wherein the aluminum oxide layer comprises alpha-Al₂O₃。

The preparation method of the cooking appliance is based on the same inventive concept as the cooking appliance, so that at least the advantages of the cooking appliance in the first aspect are provided, and the detailed description is omitted.

In one possible implementation, the thermal spray includes at least one of plasma spray, electric arc spray, or supersonic flame spray.

In one possible implementation, the operating conditions of the arc spraying include:

the voltage is 20-40V (volt);

the current is 100-380A (ampere);

the time is 0.2-2 min (minutes).

In one possible implementation, the operating conditions of the plasma spraying include:

the voltage is 20-40V;

the power is 30-45 kW (kilowatt);

the time is 0.2-2 min.

In one possible implementation, the alumina feedstock includes alpha-Al₂O₃Powder or aluminium coated alpha-Al₂O₃The wire material of (1);

and/or the material of the matrix comprises cast aluminum, wherein the mass content of silicon in the cast aluminum is less than 15%; or the mass content of silicon in the cast aluminum is 15-25%.

In one possible implementation, the thickness of the aluminum oxide layer is 30 μm to 120 μm.

In one possible implementation, after the forming the aluminum oxide layer, the preparation method further includes:

and carrying out atomized spraying treatment on at least one of fluorine-containing paint, organic silicon paint or ceramic paint to form an atomized spraying layer on the surface of the aluminum oxide layer.

The numerical ranges mentioned above are inclusive of the endpoints.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.

Detailed Description

In order to make the purpose, technical solutions and advantages of the present application clearer, the technical solutions of the present application will be clearly and completely described below with reference to the embodiments of the present application, and it should be apparent that the described embodiments are some but not all of the embodiments of the present application. All other embodiments obtained by those skilled in the art without any creative effort based on the technical solutions and the given embodiments provided in the present application belong to the protection scope of the present application. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.

The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For numerical ranges, one or more new numerical ranges may be obtained by combining the individual values, or by combining the individual values.

The term "and/or"/"as used herein is merely an associative relationship that describes the associated object, meaning that three relationships may exist, e.g., a and/or B, may mean: a exists alone, A and B exist simultaneously, and B exists alone. As used in the examples of this application and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

In this context, "inner" and "outer" are to be understood as meaning inner and outer relative to the contour of the respective component itself.

As understood by those skilled in the art, as background art is said, the existing sulfuric acid anodizing techniques have not been satisfactory. In order to overcome the traditionThe shortage of the sulfuric acid anodizing technique, those skilled in the related art have studied new techniques, such as the weakly alkaline anodizing technique, i.e., micro-arc oxidation. The film structure formed on the surface of the aluminum or aluminum alloy based substrate by the micro-arc oxidation may include alpha-alumina (i.e., alpha-Al)₂O₃) The hardness is also higher, for example, 1000-1700HV, and the corrosion resistance is also improved to a certain extent compared with the sulfuric acid anodic oxidation. However, the micro-arc oxidation method has certain disadvantages, for example, the technology has the disadvantages of high energy consumption (about 10 times of sulfuric acid anodic oxidation), high equipment input cost, high noise and the like, and the popularization and the application of the technology in the cooker industry are limited. In addition, the requirements of sulfuric acid anodic oxidation and micro-arc oxidation on the base material are high, and the purpose of surface strengthening cannot be achieved by the two technologies for treating the aluminum alloy base material with the silicon content of more than 15%. This is because the surface of the aluminum alloy (e.g., cast aluminum) contains a large amount of primary and eutectic silicon, which cannot be anodized, and a large proportion of the silicon content, e.g., silicon content of 15% or more, destroys the surface continuity of the aluminum alloy structure, thereby affecting the current distribution and heat dissipation of the anodization. Therefore, when the aluminum alloy with high silicon content (such as cast aluminum) is anodized, the defects of easy ablation, low hardness, thin film thickness, large color difference and the like generally occur, and the quality standard of hard oxidation cannot be achieved, which also limits the popularization and application of the two technologies.

In addition, in order to overcome the defects of the two technologies, the related art has successively developed the purpose of realizing surface strengthening by thermal spraying of materials such as metal wires (or metal powder) or ceramic powder, but the corrosion resistance of the product is poor due to the potential difference between the sprayed metal or ceramic and the aluminum base material, and the requirement cannot be met. However, the ceramic powders commonly used AT present, such as AT40 or AT13, all contain titanium, and because titanium is sensitive to chlorine, the titanium has strong tendency to be hydrophilic to chlorine, so that the salt water corrosion resistance of the ceramic powders cannot achieve the expected effect of product development.

In general, the existing sulfuric acid anodic oxidation mode mainly has the problems of low hardness and poor corrosion resistance; the existing micro-arc oxidation mode mainly has the problems of higher cost, higher noise and higher equipment investment; the existing sulfuric acid anodic oxidation and micro-arc oxidation modes also have the problem that the aim of surface strengthening cannot be achieved for the base material with high silicon content; the existing thermal spraying metal or titanium-containing ceramic powder can achieve the effect of surface strengthening, but the problem of corrosion resistance cannot be solved.

Therefore, in order to overcome the defects of the prior art, the problems that the prior surface strengthening schemes for the aluminum or aluminum alloy base materials cannot take account of material quality, performance, cost, equipment investment and the like are solved. The technical scheme of the embodiment of the application provides a cooking utensil and a preparation method thereof, so as to remarkably improve the hardness, corrosion resistance and wear resistance of a film layer formed on the surface of a substrate, reduce the input cost of equipment, reduce the processing cost and reduce the limitation on the substrate material.

In some embodiments, a cooking appliance is provided, which may be various common cooking devices, such as a non-stick pan, a frying pan, a pan, an electric cooker, a pressure cooker, an electric pressure cooker, a baking tray, and the like, and the specific type of the cooking appliance is not limited in the embodiments of the present application.

Specifically, in some embodiments, a cooking appliance of embodiments of the present application includes:

the aluminum oxide layer is arranged on the surface of the substrate;

wherein the aluminum oxide layer is a thermal spray coating or a cold spray coating, and the aluminum oxide layer comprises alpha-Al₂O₃。

The above-mentioned alpha-Al₂O₃Refers to Al with alpha crystal form₂O₃。α-Al₂O₃Is the most stable phase in all alumina, has the characteristics of good formability, stable crystalline phase, high hardness, good dimensional stability and the like, and also has high-temperature-resistant inertia and good stability in a high-temperature environment.

The aluminum oxide layer is a thermal spray layer or a cold spray layer, and the aluminum oxide layer may be formed by a thermal spray method or a cold spray method.

The material of the substrate may be aluminum (i.e., pure aluminum) or an aluminum alloy, and may be an aluminum composite material. The material of the base body is required to include at least aluminum, and therefore, it may be referred to as an aluminum-based base material hereinafter. The aluminum composite material is also called aluminum-based composite material, and refers to aluminum-based composite material containing other non-metal materials and aluminum, that is, aluminum-based composite material formed by combining aluminum and other non-metal materials. Illustratively, the other non-metallic material may be, for example, graphite, carbon fiber, or some ceramic-like material.

According to the cooking utensil provided by the embodiment of the application, the aluminum oxide layer is formed on the surfaces of different aluminum base materials in a cold spraying or hot spraying mode, and the formed aluminum oxide layer comprises alpha-Al₂O₃Thereby realizing the effects of high hardness, strong corrosion resistance, low investment, low processing cost and high output. In detail, alpha-Al₂O₃Is the most stable phase in all aluminum oxides and has the characteristics of good formability, stable crystalline phase, high hardness, good structural stability and the like, so compared with an aluminum oxide film layer formed by common sulfuric acid anodic oxidation, the alpha-Al film formed by the method has the advantages of being good in formability, stable in crystalline phase, high in hardness, good in structural stability and the like₂O₃The film layer can obviously improve the hardness and the corrosion resistance of the film layer, and the alpha-Al₂O₃The wear resistance of the film layer is also better, which is beneficial to prolonging the service life of the coating. Meanwhile, the aluminum oxide layer is formed on the surfaces of different aluminum base materials by utilizing a cold spraying or hot spraying mode, and compared with the existing micro-arc oxidation mode, the cold spraying or hot spraying mode can reduce the equipment input cost, reduce the production cost, improve the efficiency and reduce the noise; the method can avoid the limitation of the prior sulfuric acid anodic oxidation and micro-arc oxidation modes on the silicon content in the matrix material, can realize the effects of strengthening the surface of the matrix material with higher silicon content and enhancing the corrosion resistance, and improves the comprehensive performance of the product. In addition, compared with the existing mode of thermally spraying metal or titanium-containing ceramic powder, the alpha-Al formed by the invention₂O₃The film layer can avoid potential corrosion and chlorine-philic corrosionHigh corrosion resistance.

Tests show that the hardness of the alumina layer in the cooking utensil can reach 1000-2000HV, the wear-resistant and non-stick performance can reach not less than 3 ten thousand times, and the corrosion resistance can be improved by at least 2-5 times and above.

In addition, the base material in the cooking utensil of the embodiment of the present application is not suitable for steel materials such as carbon steel and stainless steel, glass materials, and the like. For example, when the substrate is made of steel, a special pretreatment process is required to be adopted for treatment before the aluminum oxide layer is sprayed, the requirement on pretreatment is extremely high, and otherwise the effects of improving the corrosion resistance and the like cannot be achieved; or alpha-Al provided by the embodiment of the invention₂O₃The film layer is directly covered on the surface of the matrix of the steel material, and the corrosion resistance and the like can not meet the requirements.

In some embodiments, the material of the substrate comprises cast aluminum, the cast aluminum having a silicon content of less than 15% by mass;

or the mass content of silicon in the cast aluminum is 15-25%.

The cast aluminum is different from the common deep-drawing aluminum in the forming process or the processing process. Generally, cast aluminum is extruded and molded under high temperature and high pressure molten conditions, for example, cast aluminum is cast aluminum which is poured into a mold in a molten state and cooled to form an aluminum member of a desired shape. And ordinary stretched aluminum can be formed by deep drawing in a normal state. In contrast, the cast aluminum has a more diversified product structure than common stretched aluminum, and the cast aluminum has more excellent casting performance and mechanical properties. In order to meet the molding process or processing procedure of cast aluminum, a certain proportion of silicon element is required to be contained in the cast aluminum, and the fluidity of the alloy in a molten state can be improved, so that the special molding requirement of the alloy is met. The cast aluminum is one of aluminum alloys, and the cast aluminum may be a cast aluminum alloy such as a die-cast aluminum alloy.

Silicon element in cast aluminum is one of elements that strengthen the matrix structure. The silicon has the functions of increasing the hardness, increasing the content of the silicon and improving the fluidity of casting, but the content of the silicon is not easy to be too high, and the heat resistance of the casting is influenced.

According to the embodiment of the invention, on one hand, the adopted matrix is made of cast aluminum, so that the method has the advantages of more diversified product structures, more excellent casting performance and mechanical performance and the like. On the other hand, the mass content of silicon in the cast aluminum may be less than 15%, or 15% or more, for example, 15% to 25%, further 16% to 24%, further 18% to 22%, for example, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, or the like. Compared with the existing sulfuric acid anodic oxidation and micro-arc oxidation modes, the purpose of surface strengthening and corrosion resistance increasing of cast aluminum (cast aluminum with silicon content of more than 15%) with high silicon content cannot be achieved, and popularization and application of the cast aluminum base material in the field of cookers are limited.

In order to meet different product requirements or process requirements, the specific content of the silicon element in the cast aluminum may be selectively adjusted according to actual conditions, for example, the mass content of silicon may be less than 15%, or may be 15% to 25%. Alternatively, in other embodiments, the silicon content of the cast aluminum may also be greater than 25% by mass.

It should be understood that the material of the base in the embodiment of the present invention may be cast aluminum, but is not limited thereto, for example, in other embodiments, the material of the base may also be aluminum, other types of aluminum alloys, or aluminum-based composite materials. In addition, according to the product demand, the base member can adopt the single-deck material, also can adopt the compound piece structure of multilayer, and this application embodiment does not do the restriction to the concrete number of piles of base member.

The thickness of the substrate is not limited in the embodiments of the present application, and the thickness of the substrate may be within a conventional thickness range. Preferably, the thickness of the substrate may be 0.5 to 5mm, further 0.5 to 3mm, further 1 to 3mm, further 2 to 4mm, and the like.

By controlling the thickness of the base body within a suitable range, it is possible to contribute to cost reduction and weight reduction, and to provide a cooking appliance with good strength. For example, when the thickness of the base is less than 0.5mm, the strength of the cooking utensil (pot body) is low, and the cooking utensil is easy to deform in the using process; when the thickness of the base body is more than 5mm, the weight of the cooking utensil is heavier, the cost is high, and the requirements of household consumers cannot be well met.

In some embodiments, the starting material for forming the aluminum oxide layer comprises alpha-Al₂O₃Powder or aluminium coated alpha-Al₂O₃The wire of (1).

Specifically, the raw material for forming the alumina layer may be in the form of powder, wire, or ribbon, rod, or the like, according to different process requirements. Preferably, the raw material of the aluminum oxide layer in the embodiment of the present application can be selected from two raw material types of powder or wire.

Particularly, the wire-shaped raw material adopted by the invention is aluminum-coated alpha-Al₂O₃The wire material of (1) is also called aluminum-clad alpha-Al₂O₃Powder wire material. That is, the wire-like feedstock may be in a core-shell structure comprising a core and a shell, wherein the shell is coated on the outside of the core, which may comprise α -Al₂O₃Powder (ceramic powder) the housing may comprise aluminum. During preparation, the hollow tubular aluminum material can be filled with alpha-Al₂O₃Powder, processed to form aluminum-clad alpha-Al₂O₃Powder wire material.

When an alumina layer is formed on the surface of the substrate, aluminum-coated alpha-Al is adopted₂O₃Compared with powdery spraying raw materials, the spraying raw materials of the powder wire have higher utilization rate, and the aluminum-coated alpha-Al₂O₃The powder wire contains aluminum with a lower melting point, so that the wire has a lower melting point (generally about 640 ℃), and can reach a molten state in a short time in a spraying process, and the production efficiency can be improved. And because the aluminum is coated with alpha-Al₂O₃Powder wire materialHas a low melting point, and thus can improve the adhesion fastness without fluxing by a heating gas source (such as hydrogen, propane and the like) in the processing process, thereby adopting the aluminum-coated alpha-Al₂O₃The powder wire can be combined with the aluminum base material more tightly under the condition of lower process operation requirement or lower process cost.

Therefore, the aluminum-coated alpha-Al provided by the embodiment of the invention is adopted₂O₃Compared with common wire materials or powder raw materials, the wire material has higher bonding firmness with an aluminum base material, can reduce spraying time, improves production efficiency, reduces processing cost and improves the utilization rate of raw materials. In addition, the aluminum-clad α -Al is used₂O₃Compared with powder, the powder wire has better safety, less dust pollution, safety and environmental protection.

When the adopted alumina raw material is alpha-Al₂O₃In the case of a powder, the particle size of the powder may be in the order of micrometers. For example, the particle size of the powder may be 30 to 1000 mesh, 50 to 800 mesh, further 60 to 500 mesh, further 40 to 480 mesh, further 80 to 400 mesh, further 100 to 300 mesh; typically, but not by way of limitation, the particle size of the powder may be, for example, any value in the range of 30 mesh, 40 mesh, 50 mesh, 60 mesh, 80 mesh, 100 mesh, 120 mesh, 150 mesh, 180 mesh, 200 mesh, 250 mesh, 280 mesh, 300 mesh, 500 mesh, 600 mesh, 800 mesh, 1000 mesh and any two of these point values.

By using powdered alpha-Al of suitable particle size₂O₃The cost can be reduced, and the bonding force between the alumina layer and the substrate can be improved. If the particle size of the powder is too small, the particles are larger, and the more rigorous the required process is to meet the binding force between the film layer and the substrate, the higher the process cost is; on the contrary, if the particle size of the powder is too large and the particles are smaller, the cost of milling is higher. In addition, from the viewpoint of the manufacturing process, the proper powder particle size helps to ensure the strength of the film layer, and the stress of the formed coating is moderate.

When the adopted alumina raw material is wire-shaped aluminum-coated alpha-Al₂O₃Powder wire of which diameter (outer diameter)May be 0.2 to 8mm, may be 0.5 to 5mm, may further be 1 to 4mm, and may further be 2 to 3 mm; typically, but not by way of limitation, the diameter of the wire may be, for example, 0.2mm, 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.2mm, 3.8mm, 4mm, 5mm, 6mm, 7mm, 8mm, and any value in the range of any two of these point values. It will be appreciated that, likewise, alpha-Al is encapsulated by using wire-like aluminum of suitable diameter₂O₃The powder wire can reduce the cost and improve the binding force of the alumina layer and the matrix. On one hand, when the diameter of the wire is smaller than the small diameter, the wire manufacturing cost is high; on the other hand, when the diameter is too large, the more demanding the process is to satisfy the bonding force between the film layer and the substrate, and the higher the process cost is.

In some embodiments, the aluminum comprises alpha-Al₂O₃In the powder wire material, the content of aluminum can be 10% -20%, alpha-Al₂O₃The content of the powder can be 10-80%.

In some embodiments, the thickness of the aluminum oxide layer is 30 μm to 120 μm, preferably 35 μm to 100 μm, more preferably 40 μm to 80 μm, and further may be 40 μm to 60 μm; typically, but not by way of limitation, the thickness of the aluminum oxide layer may be, for example, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, 80 μm, 90 μm, 100 μm, 110 μm, 120 μm, and any value in the range of any two of these values.

The thickness of the alumina layer is within the range of 30-120 mu m, especially within the range of 40-60 mu m, which is beneficial to reducing the cost and ensuring the mechanical property, the corrosion resistance and the like of the alumina layer. For example, when the thickness is less than 30 μm, the aluminum oxide layer is too thin, and when corrosion occurs, it easily penetrates into the substrate to cause corrosion, lowering the corrosion resistance, and furthermore, it is difficult to realize the aluminum oxide layer too thin in terms of process; when the thickness is more than 120 mu m, the alumina layer is too thick, the cost is increased, the cost is higher, and the performance is not obviously improved.

The porosity of the aluminum oxide layer is not particularly limited in the embodiments of the present application, and for example, the porosity of the aluminum oxide layer may be 0.5% to 30%, further may be 1% to 15%, further may be 5% to 15%, and the like. The proper porosity of the alumina layer helps to ensure certain performances such as hardness and corrosion resistance, for example, when the porosity of the alumina layer is too small, the area of an effective oil film formed is relatively small, which easily causes pot sticking or deterioration of corrosion resistance; when the porosity of the alumina layer is excessively large, the effective supporting area of the alumina layer is reduced, easily resulting in a reduction in hardness or strength or a reduction in wear resistance.

In some embodiments, the cooking utensil further comprises an atomized spray coating, the material of which comprises at least one of a fluorine-containing coating, a silicone coating, or a ceramic coating. Wherein the atomized spray coating is positioned on the side of the alumina layer which is far away from the matrix.

According to the embodiment of the invention, the alpha-Al is sprayed on the surface of the substrate in a cold spraying or hot spraying mode₂O₃Powder or aluminium coated alpha-Al₂O₃After the wire material of (1) is formed into an alumina layer, a fluorine-containing paint, an organic silicon paint, a ceramic paint or the like may be subjected to an atomized spray treatment on the alumina layer to form an atomized spray layer on the surface of the oxide layer.

The aluminum oxide layer may be formed on the inner surface of the substrate, or may be formed on the outer surface of the substrate, or both the inner surface and the outer surface of the substrate may be provided with the aluminum oxide layer.

Wherein, the raw material of the atomized spray coating can be fluorine-containing coating (such as fluorocarbon coating and PTFE), also can be organic silicon coating, or can be ceramic coating, or can be any combination of the coatings. Wherein the ceramic coating is different from the aforementioned ceramic powder for forming the alumina layer, and the ceramic powder may employ other types of ceramic powder than the ceramic powder for forming the alumina layer. Preferably, the raw material of the atomized spray coating is fluorine-containing coating or organosilicon coating.

Through cover one deck atomizing spraying layer on the aluminium oxide layer, help protecting the aluminium oxide layer to further promote cooking utensil's wear resistance, corrosion resisting property, make cooking utensil have good lasting on-stick life, prolonged cooking utensil's life, and then help promoting user's use and experience.

As can be seen from the above, the cooking utensil of the embodiment of the invention adopts the cold spraying or hot spraying mode on the surface (both the inner surface and the outer surface) of the roughened aluminum base material matrix to spray the alpha-Al with the chemical composition similar to that of the matrix material₂O₃The composite functional film is prepared by forming an aluminum oxide layer on the surface of a substrate and then carrying out atomization spraying treatment on the fluorine-containing coating or the organic silicon coating on the surface of the aluminum oxide layer, so that the composite functional film with high hardness, high corrosion resistance and strong wear resistance can be obtained. In particular, it comprises alpha-Al₂O₃The aluminum oxide layer of (a) can be used to improve wear resistance, corrosion resistance and hardness.

In a second aspect, in some embodiments, there is provided a method of preparing a cooking appliance, comprising the steps of:

The preparation method is simple to operate, easy to implement and easy to realize large-scale production. Meanwhile, the prepared cooking utensil comprises a base body and an aluminum oxide layer which are sequentially laminated, particularly, the aluminum oxide layer is formed on the surfaces of different aluminum base materials in a cold spraying or hot spraying mode, and the formed aluminum oxide layer comprises alpha-Al₂O₃Thereby, the effects of high hardness, strong corrosion resistance, low investment, low processing cost and high output can be realized. The preparation method of the cooking appliance has the advantages of the cooking appliance of the first aspect.

It should be understood that in the preparation method of the cooking appliance, the specific structure and components of the cooking appliance, the achieved beneficial effects and the like can be referred to the description of the cooking appliance in the first aspect. The preparation method of the cooking appliance is based on the same inventive concept as the cooking appliance, and in the description of the preparation method of the cooking appliance, the parts corresponding to the cooking appliance can refer to the related explanations in the cooking appliance, and are not described again.

In the embodiments of the present application, the manner of forming the aluminum oxide layer includes a thermal spraying method or a cold spraying method. The thermal spraying is a technology of heating a powdery or filamentous metal or nonmetal material to a molten or semi-molten state by using a certain heat source, then spraying the heated material to the surface of a pretreated substrate at a certain speed by means of flame or compressed air and the like, and depositing to form a surface coating with various functions. The thermal spraying method may be, for example, flame spraying, oxy-ethyl flame powder spraying, oxy-acetylene flame wire spraying, oxy-acetylene flame welding, High Velocity Oxygen (HVOF) flame spraying, electric arc spraying, plasma spraying, atmospheric plasma spraying, low pressure plasma spraying.

Specifically, in some embodiments, the thermal spray comprises plasma spray, electric arc spray, or supersonic flame spray.

The thermal spraying can adopt various modes such as plasma spraying, electric arc spraying, supersonic flame spraying and the like, wherein the electric arc spraying has the advantages of low equipment investment, high material utilization rate, good safety and the like; plasma spraying and supersonic flame spraying require flammable gas as the melting medium. In addition, plasma spraying and supersonic flame spraying typically employ alpha-Al in powder form₂O₃Powder, the coating formed is hard and brittle, and the electric arc spraying can adopt aluminum to coat alpha-Al₂O₃The wire of (2) has higher toughness and impact strength of the formed coating due to the aluminum component. Thus, relatively speaking, aluminum-clad α -Al is sprayed by means of arc spraying₂O₃The wire has the characteristics of good safety, high efficiency, more excellent performance of the obtained coating and the like.

Specifically, in some embodiments, the preparation method of the cooking appliance may include:

the aluminum base material after being processed and formed is subjected to certain mechanical and chemical pretreatment, wherein the pretreatment can comprise oil removal, mechanical sanding, shot blasting, sand blasting, chemical etching and the like.

Then, carrying out alpha-Al treatment on the surface of the aluminum-based material matrix₂O₃Powder or aluminium coated alpha-Al₂O₃The powder wire is treated by thermal spraying or cold spraying to form a high-hardness and corrosion-resistant aluminum oxide layer on the surface of the substrate.

Then, an atomized spray treatment, such as PTFE or silicone coating, may be performed on the surface of the alumina layer to form an atomized spray layer on the surface of the alumina layer.

In some embodiments, the substrate is formed to include α -Al on the inner surface by arc spraying₂O₃The aluminum oxide layer of (a). Specifically, the preparation method of the cooking utensil comprises the following steps:

(a) molding: the aluminum or aluminum alloy workpiece can be formed by drawing, spinning, extruding, cutting and the like to obtain the matrix.

The specific forming method of the substrate can adopt various methods known to those skilled in the art, and the specific operation method thereof is also known in the art, and the invention is not limited thereto and will not be described in detail.

(b) Pretreatment: the aluminum base material after being processed and formed is subjected to certain mechanical and chemical pretreatment, wherein the pretreatment can comprise oil removal, mechanical sanding, shot blasting, sand blasting, chemical etching and the like.

The pretreatment method can be carried out by various methods known to those skilled in the art, and the specific operation method is also known in the art, and the present invention is not limited thereto and will not be described in detail.

(c) Preparation of an aluminum oxide layer: arc spraying the substrate to form a coating containing alpha-Al on the surface of the substrate₂O₃The aluminum oxide layer of (a).

Specifically, the operating conditions of the electric arc spraying include:

equipment: metal arc spraying equipment.

Matrix: the base body is made of cast aluminum, the mass content of silicon in the cast aluminum is less than 15%, or the mass content of silicon in the cast aluminum is 15% -25%.

Alumina raw material: aluminum-clad alpha-Al₂O₃The wire material of (1);

voltage: 20-40V; in some embodiments of the invention, the voltage may be, for example, 20V, 25V, 30V, 35V, 40V, etc.

Current: 100-380A; in some embodiments of the invention, the current may be, for example, 100A, 120A, 150A, 180A, 200A, 250A, 280A, 300A, 350A, 380A, etc.

Time: 0.2-2 min; in some embodiments of the invention, the time may be, for example, 0.2min, 0.5min, 0.8min, 1min, 1.5min, 1.8min, 2min, and the like.

The thickness of the aluminum oxide layer formed is 30 μm to 120 μm, and in some embodiments of the invention, the thickness of the aluminum oxide layer may be, for example, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, 80 μm, 90 μm, 100 μm, 110 μm, 120 μm, and the like. By controlling the thickness of the aluminum oxide layer within a proper range, the base material is protected better, the cost is reduced, the weight is reduced, and the cooking utensil has good film strength, wear resistance, corrosion resistance and the like. For example, when the thickness of the aluminum oxide layer is excessively small, the aluminum oxide layer is too thin, and when corrosion occurs, it easily penetrates into the base material to cause corrosion, reducing corrosion resistance; when the thickness of the aluminum oxide layer is too large, the aluminum oxide layer is too thick, the product is thick and heavy, and the cost is higher.

Spraying aluminum-coated alpha-Al in an electric arc spraying manner₂O₃The wire forms an alumina layer on the surface of the substrate, and has the characteristics of good safety, high efficiency, more excellent performance of the obtained coating and the like, such as higher toughness and impact strength of the coating. Under the operating condition of electric arc spraying in the operating range, the method has high reliability, more sufficient spraying of coating materials, low energy consumption and aluminum-coated alpha-Al₂O₃The wire can be more fully attached to the surface of the substrate, the quality and the performance of the formed alumina layer are better, and the performance of the finally obtained cooking utensil product are betterThe user experience is good.

Wherein the aluminum is coated with alpha-Al₂O₃In the powder wire material, the content of aluminum can be 10% -20%, alpha-Al₂O₃The content of the powder can be 10-80%. Within the range, the cost can be reduced, the binding force between the coating and the base material can be improved, and the obtained coating has excellent wear resistance, corrosion resistance, film forming property and the like.

(d) Preparing an atomized spray coating: and carrying out atomized spraying treatment on the surface of the aluminum oxide layer to form an atomized spraying layer on the surface of the aluminum oxide layer.

The material for the atomized spray may be a fluorine-containing paint, a silicone paint, or the like, but the present embodiment is not limited thereto.

In addition, the specific treatment mode of the atomized spray is a common parameter or a conventional operation mode which is easily thought by those skilled in the art, and the prior art can be referred to or can be adjusted and controlled by those skilled in the art according to the actual situation, so that the detailed description thereof can be omitted.

In some embodiments, the substrate is plasma sprayed to form a coating on the inner surface of the substrate comprising α -Al₂O₃The aluminum oxide layer of (a). Specifically, the preparation method of the cooking utensil comprises the following steps:

(a) and (5) molding.

(b) And (4) pretreatment.

The step (a) and the step (b) are the same as the step (a) and the step (b) in the arc spraying method, and are not described in detail.

(c) Preparation of an aluminum oxide layer: plasma spraying the substrate to form a layer containing alpha-Al on the surface of the substrate₂O₃The aluminum oxide layer of (a).

Specifically, the operating conditions of the plasma spraying include:

equipment: metal plasma spraying equipment.

Alumina raw material:α-Al₂O₃and (3) powder.

Power: 30-45 kW; in some embodiments of the invention, the power may be, for example, 30kW, 32kW, 35kW, 38kW, 40kW, 42kW, 45kW, or the like.

The thickness of the aluminum oxide layer formed is 30 μm to 70 μm, and in some embodiments of the invention, the thickness of the aluminum oxide layer may be, for example, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, and the like. By controlling the thickness of the aluminum oxide layer within a proper range, the base material is protected better, the cost is reduced, the weight is reduced, and the cooking utensil has good film strength, wear resistance, corrosion resistance and the like. For example, when the thickness of the aluminum oxide layer is excessively small, the aluminum oxide layer is too thin, and when corrosion occurs, it easily penetrates into the base material to cause corrosion, reducing corrosion resistance; when the thickness of the aluminum oxide layer is too large, the aluminum oxide layer is too thick, the product is thick and heavy, and the cost is higher.

Under the plasma spraying operation condition within the operation range, the method has high reliability, more sufficient spraying of coating materials, low energy consumption and alpha-Al₂O₃The powder can be more fully attached to the surface of the substrate, the quality and the performance of the formed aluminum oxide layer are better, and the performance and the user experience of the finally obtained cooking utensil product are good.

In the plasma spraying process, the coating material may be in the form of powder, wire, tape, rod, etc., and is preferably in the form of powder.

Wherein the particle size of the powder may be in the micron order. For example, the particle size of the powder may be 30 to 1000 mesh, 50 to 800 mesh, further 60 to 500 mesh, further 40 to 480 mesh, further 80 to 400 mesh, further 100 to 300 mesh.

By using powdered alpha-Al of suitable particle size₂O₃The cost can be reduced, and the bonding force between the alumina layer and the substrate can be improved. Specifically, if the particle size of the powder is too small, the particles are larger, and in order to meet the binding force between the film layer and the substrate, the more rigorous the required process is, the higher the process cost is; on the contrary, if the particle size of the powder is too large and the particles are smaller, the cost of milling is higher. The granularity of the powder has certain influence on the wear resistance, the corrosion resistance, the film forming property or the adhesive force, the cost can be reduced, the binding force between the coating and the base material can be improved, and the wear resistance, the corrosion resistance, the compactness and the like of the obtained coating are excellent. In addition, from the perspective of the preparation process, the proper powder particle size helps to ensure the strength of the film layer, and the formed coating has moderate stress and cannot cause the natural collapse of the coating.

It should be noted that, in the above-mentioned arc spraying and plasma spraying processes, other operating conditions such as spraying distance, moving speed of the spray gun, etc. are not particularly limited, and as long as the requirements are met, the operation conditions can be adjusted and controlled by those skilled in the art according to actual conditions without affecting the performance of the cooking appliance, and thus detailed descriptions thereof may be omitted.

In order to facilitate understanding of the present invention, the present invention will be further described below with reference to specific examples, comparative examples and test examples.

Example 1

By adopting an electric arc spraying method, the coating is formed,forming a layer containing alpha-Al on the surface of the substrate₂O₃The aluminum oxide layer of (a).

The operating conditions of the arc spraying process include:

equipment: metal arc spraying equipment;

matrix: the base body is made of cast aluminum, and the mass content of silicon in the cast aluminum is 15-25%;

alumina raw material: aluminum-clad alpha-Al₂O₃The wire material of (1);

voltage: 25V;

current: 100A.

Time: for 1 min.

The thickness of the formed alumina layer is 40-80 μm.

An atomized spray coating treatment of PTFE was performed on the surface of the formed alumina layer to form an atomized spray coating layer on the surface of the alumina layer.

Example 2

Forming a layer containing alpha-Al on the surface of the substrate by plasma spraying₂O₃The aluminum oxide layer of (a).

The operating conditions of the plasma spraying process include:

equipment: plasma spraying equipment;

alumina raw material: alpha-Al₂O₃Powder;

voltage: 25V;

power: 45 kW.

Time: for 1 min.

The thickness of the formed alumina layer is 30 to 60 μm.

Example 3

The operating conditions of the plasma spraying process are as follows:

voltage: 40V;

the thickness of the formed alumina layer is 40-50 μm.

Otherwise, the same procedure as in example 2 was repeated.

Example 4

The operating conditions of the plasma spraying process are as follows:

power: 30 kW;

time: and 2 min.

Otherwise, the same procedure as in example 2 was repeated.

Example 5

Operating conditions of the arc spraying process are as follows:

voltage: 40V;

the thickness of the formed alumina layer is 40-50 μm.

Otherwise, the same procedure as in example 1 was repeated.

Example 6

Operating conditions of the arc spraying process are as follows:

current: 380A;

time: 0.5 min.

The thickness of the formed alumina layer is 50-60 μm.

Otherwise, the same procedure as in example 1 was repeated.

Comparative example 1

In this comparative example, the material of the substrate used was ordinary 3003 aluminum. The surface of the base body is subjected to atomized spray treatment of PTFE to form an atomized spray layer on the surface of the base body.

Comparative example 2

In this comparative example, the material of the substrate used was cast aluminum with a silicon content of 15% to 25%. The surface of the base body is subjected to atomized spray treatment of PTFE to form an atomized spray layer on the surface of the base body.

Comparative example 3

In this comparative example, the substrate used was ordinary 3003 aluminum, and an aluminum oxide layer was formed on the surface of the substrate by the conventional low-temperature sulfuric acid anodic oxidation method. An atomized spray coating treatment of PTFE was performed on the surface of the formed alumina layer to form an atomized spray coating layer on the surface of the alumina layer.

Comparative example 4

In this comparative example, a coating was formed by thermal spraying a titanium wire (powder) on the surface of a substrate by a conventional thermal spraying metal wire (powder) or ceramic powder method. And carrying out atomized spraying treatment of PTFE on the surface of the formed coating to form an atomized spraying layer on the surface of the coating.

Comparative example 5

In this comparative example, a coating was formed on the surface of the substrate by plasma spraying the titanium-containing ceramic powder (AT40) as in the prior art. And carrying out atomized spraying treatment of PTFE on the surface of the formed coating to form an atomized spraying layer on the surface of the coating.

Test examples

The respective parameters and performances of the cooking appliances prepared in the respective examples and comparative examples were tested according to the following methods. The test results are shown in table 1.

The specific test methods or standards are as follows:

1. film thickness (thickness of alumina layer in examples 1 to 6 and comparative example 3 above and thickness of coating in comparative examples 4 to 5): the cross section of the product is placed under a microscope magnifier to observe and measure the related thickness.

2. Wear resistance and non-stick test: after the direct-insertion type grinding machine is adopted for every 1000 times, the product is subjected to milk non-stick test until the milk sticks to the pan, and relevant experimental data are recorded.

3. And (3) testing the binding force: measured according to the national standard GB/T32388 cementation fastness method.

4. And (3) hardness testing: the product was placed under a vickers hardness tester for hardness measurement.

5. And (3) testing salt water corrosion resistance: the corrosion test was performed according to the cookware product national standard GB/T32388.

TABLE 1 results of Performance test of each example and comparative example

As can be seen from the above experimental data, the cooking appliance provided by the embodiment of the present invention has better corrosion resistance and wear resistance and higher hardness than the cooking appliance of the comparative example as a whole.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

It is noted that a portion of this patent application contains material which is subject to copyright protection. The copyright owner reserves the copyright rights whatsoever, except for making copies of the patent files or recorded patent document contents of the patent office.

Claims

1. A cooking appliance, characterized in that it comprises:

an aluminum oxide layer disposed on a surface of the substrate;

2. The cooking appliance of claim 1, wherein the material of the substrate comprises cast aluminum having a silicon content of less than 15% by mass;

or the mass content of silicon in the cast aluminum is 15-25%.

3. The cooking appliance of claim 1, wherein the raw material forming the aluminum oxide layer comprises α -Al₂O₃Powder or aluminium coated alpha-Al₂O₃The wire of (1).

4. The cooking appliance of claim 1, wherein the aluminum oxide layer has a thickness of 30 μ ι η to 120 μ ι η.

5. The cooking appliance of any one of claims 1-4, wherein the cooking appliance further comprises an atomized spray coating, wherein a material of the atomized spray coating comprises at least one of a fluorine-containing coating, a silicone coating, or a ceramic coating.

6. A method of preparing a cooking appliance, comprising the steps of:

7. The method of making a cooking appliance of claim 6, wherein the thermal spray comprises at least one of plasma spray, electric arc spray, or high velocity flame spray.

8. The method for preparing a cooking appliance according to claim 7, wherein the operating conditions of the arc spraying include:

the voltage is 20-40V;

the current is 100-380A;

the time is 0.2-2 min.

9. The method for preparing a cooking appliance according to claim 7, wherein the operating conditions of the plasma spraying include:

the voltage is 20-40V;

the power is 30-45 kW;

the time is 0.2-2 min.

10. The method of preparing a cooking appliance according to any one of claims 6 to 9, wherein the alumina source comprises alpha-Al₂O₃Powder or aluminium coated alpha-Al₂O₃The wire material of (1);

11. The method of any one of claims 6 to 9, wherein the thickness of the aluminum oxide layer is 30 to 120 μm.

12. The method of manufacturing a cooking appliance according to any one of claims 6 to 9, wherein after the forming the aluminum oxide layer, the method further comprises: