CN114790344A

CN114790344A - Non-stick coating and cookware

Info

Publication number: CN114790344A
Application number: CN202210322367.XA
Authority: CN
Inventors: 瞿义生; 李超; 袁华庭; 张明
Original assignee: Wuhan Supor Cookware Co Ltd
Current assignee: Wuhan Supor Cookware Co Ltd
Priority date: 2022-03-29
Filing date: 2022-03-29
Publication date: 2022-07-26

Abstract

The application provides a non-stick coating and a cooker, wherein the non-stick coating is formed by composite powder with particle form, each particle comprises non-stick powder and carbon fluoride powder, the non-stick powder forms an outer layer of the particle, the carbon fluoride powder is wrapped inside the outer layer formed by the non-stick powder, the carbon fluoride powder comprises graphite fluoride and/or graphene fluoride, and the mass fraction of fluorine atoms in the carbon fluoride is 30% -61%. The composite powder according to the present application can form a coating on a substrate that can have good initial non-stick properties and can be permanently non-stick with a high non-stick life.

Description

Non-stick coating and cookware

Technical Field

The application relates to the technical field of coatings, in particular to a non-stick coating and a cooker.

Background

In the prior art, the non-stick cookware formed by the fluororesin has better non-stick performance. However, the coating formed by the fluororesin has the defects of poor wear resistance, high possibility of scratching and damaging, poor high temperature resistance and easy aging and discoloration, so that the non-stick service life of the coating is short.

In other non-stick techniques, conventional materials are used to form a non-stick coating on the surface of the cookware. However, although the non-stick coating formed by the method has long non-stick life and good scratch and abrasion resistance, the grade of initial non-stick property is not enough and cannot meet the requirement of national standard on the initial non-stick property.

Disclosure of Invention

Therefore, the purpose of the present application is to provide a non-stick coating and a cooker, so as to solve the problem that the non-stick coating in the prior art cannot reach the standard in initial non-stick property and cannot be permanently non-stick, so that the non-stick service life is poor.

According to a first aspect of the present application, there is provided a non-stick coating formed from a composite powder having a particulate form, each particle of the composite powder including a non-stick powder and a powder of a carbon fluoride material, the non-stick powder forming an outer layer of the particle; and carbon fluoride material powder is wrapped inside the outer layer formed by the non-stick powder, wherein the carbon fluoride material powder comprises graphite fluoride and/or graphene fluoride, and the mass fraction of fluorine atoms in the carbon fluoride material is 30-61%.

In an embodiment, the non-stick powder comprises a spray material powder or a fluororesin powder, wherein the spray material powder comprises at least one of a titanium powder, a titanium alloy powder, an iron powder, a stainless steel powder, a cast iron powder, a copper alloy powder, an aluminum alloy powder, a nickel powder, and a nickel alloy powder.

In an embodiment, the volume ratio of the non-stick powder to the fluorocarbon material powder is 3:1 to 10: 1.

In an embodiment, the non-stick powder has a particle size of 5 μm to 15 μm, the carbon fluoride powder has a particle size of 10 μm to 50 μm, and a particle size ratio of the carbon fluoride powder to the non-stick powder is 2:1 to 10:1, wherein the composite powder has a particle size of 20 μm to 100 μm.

According to a second aspect of the present application, there is provided a non-stick coating formed from a composite powder having a particle form, each particle comprising a non-stick powder and a powder of a carbon fluoride material, the powder of the carbon fluoride material being doped in the non-stick powder by a binder, wherein the powder of the carbon fluoride material comprises graphite fluoride and/or graphene fluoride, and the mass fraction of fluorine atoms in the carbon fluoride material is 30% to 61%.

In some embodiments, the non-stick powder comprises a spray material powder comprising at least one of a titanium powder, a titanium alloy powder, an iron powder, a stainless steel powder, a cast iron powder, a copper alloy powder, an aluminum alloy powder, a nickel powder, and a nickel alloy powder, or a fluororesin powder.

In an embodiment, the binder includes at least one of a cellulose-based binder and an alcohol-based binder.

In an embodiment, the adhesive is a cellulose adhesive, and the non-stick coating is a mixed layer formed by non-stick powder, carbon fluoride powder and the adhesive.

In an embodiment, the adhesive is an alcohol adhesive, and the non-stick coating is a mixed layer formed by non-stick powder and carbon fluoride powder.

In an embodiment, the volume ratio of the non-stick powder, the carbon fluoride material, and the binder is (20-30): (5-10): (1-2).

In embodiments, the non-stick powder and the fluorocarbon material powder each have a particle size in the range of 10 μm to 40 μm, and the ratio of the particle sizes of the fluorocarbon material powder and the non-stick powder is 1:2 to 3: 2; the particle diameter of the composite powder is 20-100 μm.

According to a second aspect of the present application, a cooker is provided, comprising the non-stick coating described above, which is formed by means of cold spraying.

Drawings

The above and other objects and features of the present application will become more apparent from the following description of the embodiments taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a schematic view of the structure of one particle in a composite powder in coated form according to an embodiment of the present application;

fig. 2 is a schematic view of the structure of one particle in a composite powder in a granulated form according to an embodiment of the application.

Detailed Description

The inventive concepts of the present application will be described more fully hereinafter.

The fluorinated carbon material may include graphite fluoride and graphene fluoride. Graphite fluoride is a graphite intercalation compound generated by direct reaction of carbon and fluorine, and has excellent non-stick performance due to low surface free energy, good thermal stability and chemical stability, long-term hydrophobicity for acid or alkali aqueous solution, extremely difficult wetting and 145 degrees of contact angle with water. The fluorinated graphene is two-dimensional flaky fluorinated graphite, and has excellent low surface energy and non-stick performance and better toughness. Thus, the initial non-stick properties of the non-stick coating can be improved by the fluorinated carbon material.

However, the fluorocarbon material has a low density and a light weight, and thus cannot be applied by spraying alone to form a coating on a substrate. Thus, in order to obtain a coating that is initially less sticky, it is necessary not only to select an appropriate carbon fluoride material, but also to consider how it will be better formed on the substrate.

The inventors found that, by using a spray coating material powder, a fluororesin powder, or the like as a non-stick powder, forming a composite powder by coating a carbon fluoride material in an outer layer formed of the non-stick powder, or forming a composite powder by uniformly doping a carbon fluoride material in a non-stick powder, it is possible to improve the initial non-stick property of a coating layer and to realize a coating layer having an initial non-stick property that meets the requirements, due to the carbon fluoride material contained in the composite powder. Furthermore, the fluorocarbon material has a relatively small coefficient of friction compared to the spray material powder, and thus is relatively non-wear resistant. The inventors have also found that a high hardness of the spray material powder can effectively compensate for the disadvantage of the carbon fluoride material that is not wear resistant. Therefore, in some embodiments, the composite powder is used to form the non-stick coating on the surface of the substrate, and the high-hardness spraying material powder can effectively protect the carbon fluoride material, so that the whole non-stick coating has better wear resistance, and the non-stick coating with excellent initial non-stick property and lasting non-stick effect is obtained. The carbon fluoride material has a relatively large friction coefficient as compared with the fluororesin powder. Therefore, in other embodiments, the fluorocarbon material in the composite powder can improve the scratch resistance of the coating formed by the fluororesin, so that the non-stick coating with excellent initial non-stick property and lasting non-stick effect is obtained.

The cold spraying combines the composite powder and the base material together through high-speed impact at a relatively low temperature, the powder and the base material are subjected to plastic deformation at a softening temperature, and the powder and the base material are mutually matched under the action of mechanical force to deposit a coating.

In addition, the inventor also finds that the composite powder can form a non-stick coating with good binding force on a substrate by means of cold spraying. Cold spraying has a relatively lower temperature than thermal spraying and thus does not suffer from high temperature oxidation, gasification, melting, crystallization, etc. that affect the non-stick coating properties.

The non-stick coating formed by the composite powder in the clad form of the present application will be described in detail with reference to the exemplary embodiments.

According to a first aspect of the present application, there is provided a non-stick coating formed by spraying a composite powder in a clad form. As shown in fig. 1, the composite powder has a particle form, each particle 10 including a non-stick powder 11 and a fluorocarbon material powder 12. The non-stick powder 11 is wrapped around the outer surface of each particle of the fluorocarbon material powder 12 to form an outer layer of particles. The fluorinated carbon material can comprise graphite fluoride and/or graphene fluoride, and the mass fraction of fluorine atoms in the fluorinated carbon material is 30% -61%.

According to the application, at least one powder 12 of carbon fluoride material may be wrapped inside the outer layer formed by the non-stick powder 11. The carbon fluoride material powder may include graphite fluoride and/or graphene fluoride, and the mass fraction of fluorine atoms in the carbon fluoride material is 30% to 61%. When the mass fraction of fluorine atoms in the carbon fluoride material is less than 30%, the improvement effect of the non-stick performance of the obtained coating is poor, and when the mass fraction of fluorine atoms in the carbon fluoride material is 30% -61%, the obtained coating has good non-stick performance. For the fluorinated carbon material powder used herein, the higher the degree of fluorination (i.e., mass fraction of fluorine atoms), the lower the surface energy, and the better the non-tackiness. In the composite powder, the fluorocarbon material serves as an inner layer of the composite powder particles, and the nonstick powder serves as an outer layer of the composite powder particles. During the process of preparing the non-stick coating, a portion of the particles may be deformed by heat and another portion of the particles may be broken. Thus, the carbon fluoride material located inside is partially exposed and uniformly distributed in the non-stick coating by spraying, exerting an effect of initial non-sticking. In addition, the graphite fluoride and the fluorinated graphene have excellent hydrophobic performance, and the non-stick coating formed by the composite powder can reduce the infiltration degree of corroded media, so that the corrosion resistance of the coating can be enhanced.

According to exemplary embodiments of the present application, the mass fraction of fluorine atoms in the fluorinated carbon material powder may be 35-61%, 40-50%, 40-61%, 30-50% or 50-61%, preferably 40-61%, more preferably 55-61%.

According to the application, the non-stick powder can be in various forms, and spray material powder and fluororesin powder can be adopted, and composite powder formed by the spray material powder is described in the following with reference to the embodiment.

In some embodiments, the non-stick powder may include a spray material powder having a hardness and a fluorocarbon material having a better thermal stability below 450 ℃, so that the non-stick coating formed from the resulting composite powder has better wear resistance and thermal stability, thereby improving the durable non-stick property of the coating.

In order to improve the hardness and wear resistance of the non-stick coating, in the embodiment, the non-stick powder is a spray material powder, and the hardness of the spray material powder is higher than that of the fluorocarbon material powder. For example, the spray material powder may include at least one of titanium powder, titanium alloy powder, iron powder, stainless steel powder, low carbon steel powder, high carbon steel powder, cast iron powder, copper alloy powder, aluminum alloy powder, nickel alloy powder, titanium oxide powder, titanium nitride powder, titanium carbide powder, ferroferric oxide powder, iron oxide powder, ferrous oxide powder, aluminum oxide powder, chromium oxide powder, and nickel oxide powder.

Preferably, among the spray material powders, a portion of the spray material powders have better plasticity, and the composite powder formed by the spray material powders having an elongation at break of more than 12% can be better bonded to the substrate by means of cold spraying. For example, the spray material powder may preferably include at least one of titanium powder, titanium alloy powder, iron powder, stainless steel powder, cast iron powder, copper alloy powder, aluminum alloy powder, nickel powder, and nickel alloy powder. However, the examples of the spray material powder according to the present application are not limited thereto, and those skilled in the art can select a plastic powder that is conventional in the art as the non-stick powder of the present application under the teaching of the present application.

Now, a composite powder formed of the fluororesin powder will be described with reference to examples.

In other embodiments, the non-stick powder may include a fluororesin powder. The fluororesin powder includes at least one of Polytetrafluoroethylene (PTFE) resin, ethylene-tetrafluoroethylene copolymer (ETFE), copolymer of perfluoropropyl perfluorovinyl ether and Polytetrafluoroethylene (PFA) resin, in which polytetrafluoroethylene is the main component. The fluororesin powder has excellent non-stick performance, and the carbon fluoride material has certain hardness and better thermal stability, so that the non-stick coating formed by the obtained composite powder has better wear resistance and thermal stability, and the lasting non-stick property of the coating can be improved.

When the composite powder is formed by coating, in the process of preparing the raw material for preparing the composite powder, not only the suitable non-stick powder needs to be selected, but also the particle size, the addition ratio, and the like of the fluorocarbon material and the non-stick powder need to be set, so as to facilitate the formation of a stable coating structure.

In the examples, the volume ratio of the non-stick powder to the fluorocarbon powder is 3:1 to 10: 1. For example, the non-stick powder may be 30 parts to 50 parts by volume and the fluorocarbon powder may be 5 parts to 10 parts by volume. When the volume ratio of the non-stick powder to the carbon fluoride material powder is less than 3, the volume ratio of the carbon fluoride material in the composite powder is relatively large, so that the coated powder has an incomplete structure, the strength is reduced, and the wear resistance is poor; when the volume ratio of the non-stick powder to the fluorocarbon material powder is more than 10, the volume ratio of the fluorocarbon material having the non-stick function is small, which tends to result in a large amount of defective products in the final non-stick coating and poor initial non-stick property.

In the examples, the non-stick powder has a particle size of 5 μm to 15 μm, the carbon fluoride material powder has a particle size of 10 μm to 50 μm, and the ratio of the particle sizes of the carbon fluoride material powder and the non-stick powder is 2:1 to 10: 1. That is, the non-stick powder has a relatively small particle size, so that the non-stick powder can compactly form the outer layer of the particles and coat the fluorocarbon material powder, thereby forming a stable coating structure. In particular, the non-stick powder may have a particle size of 5 μm to 15 μm. When the particle size of the non-stick powder is less than 5 mu m, the powder is too fine, more fine powder is contained in the finally formed non-stick coating, the requirement of subsequent spraying construction is not met, and the qualified rate is low. When the particle size of the non-stick powder is larger than 15 μm, the formed coating outer layer has large pores, so that the structure is loose, the particles of the formed non-stick coating are larger, the power required by subsequent spraying construction is larger, and the production cost is increased. In the embodiment, the particle size of the carbon fluoride material powder is 10-50 μm, when the particle size of the carbon fluoride material powder is less than 10 μm, the powder is too fine, the preparation process difficulty is large, and the cost is high; when the particle size of the carbon fluoride material powder is larger than 50 μm, the powder is too coarse, and the particle size of the carbon fluoride material in the non-stick coating layer is too large, resulting in a decrease in strength of the non-stick coating layer.

After the raw materials for preparing the composite powder are prepared, a step of preparing the composite powder is followed. According to the application, the composite powder can be prepared by means of mechanical grinding. As an example, the method may be a ball milling method, in which the non-stick powder and the fluorocarbon material powder are first added to a ball mill and ball milled under the condition of adding a ball milling medium, and after ball milling, the particle powder in a coated form is obtained, and then the obtained particle powder in a coated form is placed in a muffle furnace to be sintered, so as to obtain the composite powder in a particle form. The concrete parameters of the ball stone grinding method are as follows: the ball milling medium can be ethanol or isopropanol; the rotation speed of the ball milling can be 1000r/min-5000 r/min; the ball-material ratio of the ball mill can be 2:1-8: 1; the ball milling time can be 20-50 h; the degree of vacuum for sintering may be 1X 10 ^-3 Pa-5×10 ^-3 Pa; the sintering temperature can be 120-250 ℃, and the sintering time can be 2-4 h.

According to the application, when the ball milling equipment is in operation, the ball stones collide and rub at high speed, and the friction force enables the non-stick powder and the carbon fluoride material powder to mutually penetrate, be embedded and be connected. The non-stick powder has relatively small particle size, so that the non-stick powder can be uniformly coated on the surface of the carbon fluoride material powder through ball milling. The ball milling medium is added into the ball mill, so that the non-stick powder and the carbon fluoride powder are uniformly dispersed, and the problem that the coating is not uniform enough due to the fact that the non-stick powder with large specific gravity sinks is avoided.

After the steps, the final composite powder can be obtained. In the composite powder, the volume ratio of the spray material and the carbon fluoride material may be 2:1 to 10:1, and the particle diameter of each composite powder may be 20 μm to 100 μm. When the particle size of the composite powder particles is less than 20 micrometers, the powder is too fine and is easy to absorb moisture and agglomerate, so that a powder feeding pipe of equipment matched with spraying equipment is easy to block, and unsmooth production is caused; when the particle diameter of the composite powder is larger than 100 μm, the composite powder has poor strength, low yield and high cost, which is not favorable for production control.

The method of preparing the composite powder is described above in connection with the exemplary embodiments. By the above method, a composite powder in which the carbon fluoride material is coated in the spray coating material powder can be obtained. The composite powder has good non-stick properties, structural strength and good workability, and thus can be used to form non-stick coatings according to the inventive concept.

According to an exemplary embodiment, a non-stick coating may be formed on a surface of a substrate (such as a base of cookware) by employing a layer forming process (such as a cold spray process) in the prior art. For example, a cold spray process may be used to form the non-stick coating. However, the inventive concept is not limited to the process of forming the non-stick coating.

According to the application, one non-stick powder and the carbon fluoride material can be selected to form composite powder, and multiple non-stick powders and the carbon fluoride material can be selected to be mixed to form composite powder. Since the melting points of different non-stick powders may be different, in view of the ease of control of the subsequent spraying process, according to the present application, in a preferred embodiment, the non-stick coating may be formed by cold spraying the composite powder.

In the embodiment, one composite powder can be used for spraying to form the non-stick coating, or multiple composite powders can be used for spraying to form the non-stick coating, when multiple composite powders are used for spraying, the composite powders can be separately and sequentially sprayed to form the non-stick coating, and the composite powders with better non-stick performance can be placed in the last spraying. For example, but not limited to, a composite powder formed of a fluororesin may be sprayed on the last time to form a top layer of a non-stick coating.

According to the present application, the above composite powder is deposited onto the inner surface of a substrate by a cold spray process to form a non-stick coating. The cold spray process is to form a dense coating by impinging the coating powder onto a substrate with supersonic gas and solid-phase gas flow at normal temperature or at a relatively low temperature. Cold spraying is carried out by impacting powder particles onto a substrate at a high speed to bond the powder particles and the substrate together, and the powder particles and the substrate are plastically deformed at a softening temperature and mutually fit under the action of mechanical force to deposit a coating.

In the process of preparing the non-stick coating by cold spraying, the inventor finds that the composite powder and the base material can be mutually occluded to form the non-stick coating with better bonding force by plastic deformation of one of the composite powder and the base material. Part of the sprayed powder has higher brittleness, and plastic deformation is difficult to occur in direct spraying, so that the non-stick coating can be prepared by depositing the composite powder on the pot body through cold spraying in a mode of preheating the matrix in advance.

Specifically, before performing the cold spraying process, the surface of the substrate needs to be heated to a softening temperature by a heat treatment method to soften the surface of the substrate, and then, in the cold spraying process, the hard composite powder is sprayed on the softened surface of the substrate, so that the composite powder and the surface of the substrate are engaged with each other to form the non-stick coating.

According to the present application, taking a cooker as an example, the non-stick coating can be prepared by the following steps:

step S101, firstly, the inner surface of the cooker is preheated to 350-450 ℃ to soften the inner surface of the cooker.

Step S102, spraying the prepared composite powder on the inner surface of the softened cooker through a cold spraying process to form a non-stick coating, so as to prepare the non-stick cooker.

According to a specific example, a cold spraying mode can be adopted, and specifically, the parameters of the cold spraying are as follows: the cold spraying carrier gas is nitrogen, the carrier gas pressure is 10MPa to 15MPa, the preheating temperature of the composite powder is 250 ℃ to 350 ℃, the spraying distance is 25mm to 35mm, the powder feeding speed is 10g/min to 90g/min, the spray gun moving speed is 1mm/s to 3mm/s, and the base material rotating speed is 80r/min to 120 r/min.

The non-stick coating formed by the composite powder in granulated form of the present application will be described in detail below with reference to exemplary embodiments.

According to a second aspect of the present application, there is provided a non-stick coating formed by spraying a composite powder in granulated form. As shown in fig. 2, the composite powder has a particle form, and each particle 20 includes a nonstick powder 21 and a fluorocarbon material powder 22 doped in the nonstick powder 21 by a binder. The carbon fluoride material powder comprises graphite fluoride and/or graphene fluoride, and the mass fraction of fluorine atoms in the carbon fluoride material is 30% -61%.

According to the application, the carbon fluoride material powder may include at least one of graphite fluoride powder and graphene fluoride powder, and the mass fraction of fluorine atoms in both the graphite fluoride and the graphene fluoride is 30% to 61%. When the mass fraction of fluorine atoms in the carbon fluoride material is less than 30%, the improvement effect of the non-stick performance of the obtained coating is poor, and when the mass fraction of fluorine atoms in the carbon fluoride material is 30% -61%, the obtained coating has good non-stick performance. For the carbon fluoride material powder used herein, the higher the degree of fluorination (i.e., mass fraction of fluorine atoms), the lower the surface energy, and the better the non-tackiness.

According to the application, the carbon fluoride material in the composite powder can be uniformly doped in the non-stick powder through the binder by means of granulation. When the non-stick coating is prepared by the composite powder, the carbon fluoride material in the composite powder is also uniformly distributed in the non-stick coating, and the initial non-stick effect is exerted. According to exemplary embodiments of the present application, the mass fraction of fluorine atoms in the fluorinated carbon material powder may be 35% to 61%, 40% to 50%, 40% to 61%, 30% to 50%, or 50% to 61%, preferably, 40% to 61%, and more preferably, 55% to 61%.

According to the present application, the non-stick powder may be in various forms, and spray coating material powder may be used, or fluororesin powder may also be used, and the composite powder formed by the spray coating material will be described with reference to the following examples.

In order to increase the hardness and wear resistance of the non-stick coating to increase the durable non-stick property, in the embodiment, the hardness of the spray material powder is higher than that of the fluorocarbon material powder. For example, the spray material powder may include at least one of titanium powder, titanium alloy powder, iron powder, stainless steel powder, low carbon steel powder, high carbon steel powder, cast iron powder, copper alloy powder, aluminum alloy powder, nickel alloy powder, titanium oxide powder, titanium nitride powder, titanium carbide powder, ferroferric oxide powder, iron oxide powder, ferrous oxide powder, aluminum oxide powder, chromium oxide powder, and nickel oxide powder.

Preferably, among the spray material powders, a part of the spray material powders has better plasticity, and the composite powder formed by the spray material powders with the breaking elongation of more than 12 percent can be better bonded to the matrix by means of cold spraying. For example, the spray material powder may preferably include at least one of titanium powder, titanium alloy powder, iron powder, stainless steel powder, cast iron powder, copper alloy powder, aluminum alloy powder, nickel powder, and nickel alloy powder. However, the example of the spray material powder according to the present application is not limited thereto, and those skilled in the art can select a plastic powder that is conventional in the related art as the spray material powder of the present application under the teaching of the present application.

The composite powder formed of the fluororesin powder will be described below with reference to examples.

In other embodiments, the non-stick powder may include a fluororesin powder. The fluororesin powder includes at least one of Polytetrafluoroethylene (PTFE) resin, ethylene-tetrafluoroethylene copolymer (ETFE), copolymer of perfluoropropyl perfluorovinyl ether and Polytetrafluoroethylene (PFA) resin, in which polytetrafluoroethylene is the main component. The fluororesin powder has excellent non-stick performance, and the carbon fluoride material has certain hardness and better thermal stability, so that the non-stick coating formed by the obtained composite powder has better wear resistance and thermal stability, and the lasting non-stick performance of the coating can be improved.

In embodiments, the particle size of the non-stick powder and the particle size of the fluorocarbon material powder are not substantially different, and illustratively, the particle size of the non-stick powder and the particle size of the fluorocarbon material powder may be 10 μm to 40 μm. When the particle size of the powder is less than 10 mu m, the powder is too fine, the preparation process difficulty is high, and the cost is high; when the particle size of the non-stick powder is larger than 40 μm, the particles of the formed composite powder are larger, and the power required by subsequent spraying construction is larger, so that the production cost is increased. And the particle diameter ratio of the carbon fluoride material powder to the non-stick powder is 1:2-3: 2.

The particle size of the above-mentioned material may be the maximum length of the particles of the respective materials, and is not particularly limited to the material having a spherical or spheroidal shape. For example, and without limitation, when a material has an oval shape, the particle size dimension of the material may refer to the length of its major axis.

In an embodiment, the binder may include at least one of a cellulose-based binder, which may include at least one of hydroxymethyl cellulose, hydroxyethyl cellulose, and hydroxypropyl methyl cellulose, and an alcohol-based binder, which may include at least one of polyvinyl alcohol, polypropylene alcohol, and other higher alcohol-based binders having six or more carbon atoms.

In the examples, the volume ratio of the non-stick powder to the fluorocarbon material powder in the composite powder is 2:1 to 6: 1. For example, the non-stick powder may be 20 parts to 30 parts by volume, the fluorocarbon powder may be 5 parts to 10 parts by volume, and the binder may be 1 part to 2 parts by volume. When the volume ratio of the non-stick powder to the carbon fluoride material powder is less than 2, the volume ratio of the carbon fluoride material in the composite powder is too large, so that the overall strength of the composite powder is reduced, and the wear resistance is poor; when the volume ratio of the non-stick powder to the fluorocarbon material powder is greater than 6, the volume ratio of the non-stick fluorocarbon material powder is small, so that more defective products are likely to be contained in the final composite powder, and the effect of improving the initial non-stick property is poor.

After the raw materials for preparing the composite powder are prepared, a step of preparing the composite powder is followed. The method for preparing the composite powder in granulated form according to the present application may comprise the following steps.

In step S201, a non-stick powder and a fluorocarbon powder are prepared, respectively.

In order to avoid the influence of mutual doping of the two on the uniform distribution of the carbon fluoride material powder in the particles, according to the application, the raw materials of the two can be respectively subjected to ball milling to obtain non-stick powder and the carbon fluoride material powder which have certain particle sizes respectively, and then the non-stick powder and the carbon fluoride material powder are mixed.

Step S202, dissolving 1-4% of binder, 0.5-2% of dispersant and 1-2% of defoamer into the balance of deionized water to prepare slurry. Wherein, the defoaming agent can be polyether modified silicone oil or organic silicone oil, and the dispersing agent can be citric acid or triethyl hexyl phosphoric acid. According to the present application, a dispersant and an antifoaming agent may be selected as auxiliaries, so that the non-stick powder and the fluorocarbon material powder are uniformly dispersed in the slurry, and of course, other suitable auxiliaries may be selected according to actual needs, and the present application is not limited thereto.

Step S203, after the slurry is prepared, the prepared non-stick powder and the carbon fluoride material powder are dispersed into the slurry according to the weight of the non-stick powder and the carbon fluoride material powder accounting for 20% -70% of the total weight of the slurry.

And S204, conveying the slurry to a high-speed liquid throwing disc to form liquid drops, blowing the liquid drops into a drying tower by utilizing hot air, and allowing the liquid drops to temporarily stay in the descending process to finally form granulated powder. The rotating speed of the high-speed liquid throwing disc can be controlled within the range of 6000 rpm-10000 rpm, preferably 7000 rpm-8000 rpm, so as to form a granulation powder structure in which the carbon fluoride material powder is uniformly doped in the non-stick powder. The temperature of the hot air can be controlled within the range of 60 ℃ to 100 ℃, the temperature of the drying tower can be controlled within the range of 100 ℃ to 380 ℃, and the transient residence time of the liquid droplets in the drying tower can be controlled within the range of 5 seconds to 15 seconds.

And S205, sintering the granulation powder obtained after spray drying, wherein the initial sintering temperature can be 25 ℃, the heating speed can be 5-10 ℃/min, the temperature is raised to 200 ℃, and then the temperature is preserved for 3-10 h. According to the application, the required effect can be achieved by a slower temperature rise speed and a shorter heat preservation time due to the smaller particle size of the granulated powder, and the energy can be saved.

According to the composite powder of the present application, the particle diameter of the composite powder may be 20 μm to 100 μm. When the particle size of the composite powder particles is less than 20 micrometers, the composite powder particles are too small, so that the composite powder particles are easy to agglomerate after moisture absorption, and a powder feeding pipe of equipment matched with thermal spraying equipment is easy to block, so that the production is not smooth; when the particle size of the composite powder is larger than 100 μm, the composite powder is too large, the strength of the composite powder is poor, the yield is low, the cost is increased, and the production control is not facilitated.

According to the method for preparing the coating layer of the composite powder of the embodiment of the present application, reference may be made to the method for preparing the coating layer in the clad structure described above.

The present application will be described in detail with reference to examples, but the scope of the present application is not limited to the examples.

Example 1

The pot according to example 1 was prepared by the following method.

And step S10, providing the cast iron pan base body.

Step S20, providing a non-stick powder and a carbon fluoride material powder. An aluminum alloy powder having an average particle diameter of 30 μm was prepared as a non-stick powder, and a fluorinated graphene powder having an average particle diameter of 30 μm and a mass fraction of fluorine atoms of 30% was prepared as a fluorinated carbon material powder, and the aluminum alloy powder and the fluorinated carbon material powder were mixed at a volume ratio of 5: 1.

Step S30, a slurry including a non-stick powder and a carbon fluoride material powder is prepared.

Preparing slurry: polyvinyl alcohol is selected as an alcohol binder, and the slurry can comprise 3% of polyvinyl alcohol, 0.8% of triethylhexylphosphoric acid, 1.5% of organic silicon oil and the balance of deionized water in percentage by weight, and is prepared into slurry according to the components and the content.

Preparing slurry: the prepared non-stick powder and fluorocarbon material powder were added to the prepared slurry so as to prepare a slurry, with the total weight of the non-stick powder and fluorocarbon material powder accounting for 60% of the total weight of the slurry.

Step S40, spray drying the slurry.

The slurry is conveyed to a high-speed liquid throwing disc at 8000 rpm, then the slurry is thrown out by the liquid throwing disc to form liquid drops, then the liquid drops are blown into a drying tower at 300 ℃ by hot air at 80 ℃, and the liquid drops drop after short retention in the descending process, so that granules containing certain moisture in a granulation form are obtained.

Step S50, sintering the formed granules in granulated form to remove moisture contained therein, the sintering parameters being: the initial temperature of sintering can be 25 ℃, the heating rate can be 8 ℃/min, the temperature is increased to 200 ℃, and then the temperature is kept for 7h, so that the composite powder in the form of particles is obtained.

Step S60, performing cold spraying on the surface of the cookware base by adopting the composite powder with the granularity of 40-50 μm to form the non-stick coating with the thickness of 60 μm, wherein the cold spraying parameters are as follows: the spraying carrier gas was nitrogen, the carrier gas pressure was 12MPa, the preheating temperature of the composite powder was 300 ℃, the spraying distance was 30mm, the powder feeding rate was 40g/min, the moving rate of the spray gun was 1mm/s, and the rotational speed of the pot base was 100r/min, to obtain the pot of example 1.

Example 2

The pot of example 2 was manufactured in the same manner as in example 1, except that in the step of step S20, graphite fluoride having the same mass fraction of fluorine atoms was used instead of graphene fluoride to form a composite powder.

Example 3

The pot of example 3 was manufactured in the same manner as in example 1, except that in the step of step S20, graphite fluoride and graphene fluoride each having a mass fraction of 30% of fluorine atoms were used and mixed at 1:1 mass to form a combined powder instead of the graphene fluoride to form a composite powder.

Example 4

The pot of example 4 was manufactured in the same manner as in example 1, except that fluororesin powder was used as the non-stick powder instead of the aluminum alloy.

Example 5

A pot of example 5 was produced in the same manner as in example 1, except that graphene fluoride having a mass fraction of fluorine atoms of 40% was used instead of graphene fluoride having a mass fraction of fluorine atoms of 30%.

Example 6

The pot of example 6 was manufactured by the same method as example 1, except that the graphene fluoride having a mass fraction of fluorine atoms of 60% was used instead of the graphene fluoride having a mass fraction of fluorine atoms of 30%.

Example 7

Step S10, preparing a cast iron cookware base and pretreating the surface of the cookware base.

In step S20, a composite powder is prepared.

In step S21, a fluorinated graphene powder having an average particle diameter of 30 μm and a mass fraction of fluorine atoms of 30% is prepared as a carbon fluoride material.

Stainless steel powder having an average particle diameter of 10 μm was prepared as a non-stick powder.

Step S22, mixing 40 parts by volume of stainless steel powder and 8 parts by volume of graphite fluoride in a ball mill, performing ball milling under the condition of ethanol as a ball milling medium, and after ball milling, placing the obtained particle powder in a muffle furnace to sinter to obtain composite powder. Wherein the rotation speed of ball milling is 4000 r/min; the ball-material ratio of ball milling is 4: 1; the ball milling time is 30 h; the degree of vacuum of sintering is 3X 10 ^-3 Pa; the sintering temperature is 180 ℃ and the sintering time is 3h, so that the composite powder is prepared.

Step S30, performing cold spraying on the cookware substrate by adopting composite powder with the granularity of 40-50 μm to form a non-stick coating cookware with the thickness of 60 μm, wherein the cold spraying parameters are that spraying carrier gas is nitrogen, the carrier gas pressure is 12MPa, the preheating temperature of the composite powder is 300 ℃, the spraying distance is 30mm, the powder feeding speed is 40g/min, the spray gun moving speed is 1mm/S, and the cookware substrate rotating speed is 100 r/min.

Example 8

The pot of example 8 was manufactured in the same manner as in example 7, except that a fluororesin was used instead of a stainless steel powder in the non-stick powder to form a composite powder.

Example 9

The pot of example 9 was manufactured by cold spraying the composite powder of example 7 with the same cold spray parameters to form a primer layer having a thickness of 30 μm, and then spraying the composite powder of example 8 on the primer layer to form a surface layer having a thickness of 30 μm.

Comparative example 1

The pot of comparative example 1 was manufactured in the same manner as in example 1, except that the graphene fluoride having a mass fraction of fluorine atoms of 25% was used instead of the graphene fluoride having a mass fraction of fluorine atoms of 30%.

Comparative example 2

A pot of comparative example 2 was manufactured in the same manner as in example 1, except that graphene fluoride having a mass fraction of fluorine atoms of 10% was used instead of graphene fluoride having a mass fraction of fluorine atoms of 30%.

Comparative example 3

The pot of comparative example 3 was manufactured by using aluminum alloy powder directly sprayed on the pot base by the same spraying method as example 1 to form a composite coating layer having a thickness of 60 μm.

Comparative example 4

The pot of comparative example 4 was manufactured by using fluororesin powder directly spray coated on the pot base in the same spray coating method as example 1 to form a composite coating layer having a thickness of 60 μm.

Comparative example 5

The pot of comparative example 5 was manufactured by using stainless steel powder directly sprayed on the pot base in the same spraying method as example 1 to form a composite coating layer having a thickness of 60 μm.

TABLE 1 parameters of examples of the present application and comparative examples

Performance index testing

(1) The thickness of the non-stick coating in the pot is the same, and the performance test is carried out on the obtained pot, and the specific performance test method comprises the following steps: non-stick test method:

firstly, an initial non-adhesiveness test method: the non-stickiness test method of the fried egg in GB/T32095.2-2015 is an initial non-stickiness test and comprises a first non-stickiness test, a second non-stickiness test and a third non-stickiness test, wherein the first non-stickiness test is the best, and the third non-stickiness test is the worst.

② a method for testing permanent inadhesion: the method for testing the permanent non-stick property in GB/T32388-2015 is characterized in that the unit is times, the higher the times is, the longer the service life is, the 1000 times is used for evaluating the non-stick result once, and the times when the non-stick result is used to the grade III is recorded.

TABLE 2 test data of examples of the present application and comparative examples

Serial number	Initial non-tackiness	Permanent non-stick property
			Example 1	Ⅱ	15000
Example 2	Ⅱ	11000
			Example 3	Ⅱ	13000
Example 4	Ⅰ	15000
			Example 5	Ⅱ	17000
Example 6	Ⅰ	21000
			Example 7	Ⅱ	17000
Example 8	Ⅰ	15000
			Example 9	Ⅰ	25000
Comparative example 1	Ⅱ	4000
			Comparative example 2	Ⅱ	2000
Comparative example 3	Ⅲ	0
			Comparative example 4	Ⅰ	8000
Comparative example 5	Ⅲ	0

In conclusion, the coating formed by the composite powder can obtain better initial non-stick property and lasting non-stick property, compared with the original non-stick material, the coating has the advantages that the initial non-stick effect and the lasting non-stick effect meet the national standard, the lasting non-stick property is better, the non-stick service life is greatly prolonged, and the wear is not feared.

Although the embodiments of the present application have been described in detail above, those skilled in the art may make various modifications and alterations to the embodiments of the present application without departing from the spirit and scope of the present application. It will be understood that those skilled in the art will recognize modifications and variations as falling within the spirit and scope of the embodiments of the application as defined by the claims.

Claims

1. A non-stick coating formed from a composite powder having the form of particles, each particle comprising:

a non-stick powder forming an outer layer of said particles;

a powder of carbon fluoride material encased within an outer layer formed by the non-stick powder,

the fluorinated carbon material comprises graphite fluoride and/or graphene fluoride, and the mass fraction of fluorine atoms in the fluorinated carbon material is 30% -61%.

2. The non-stick coating of claim 1, wherein the non-stick powder comprises a spray material powder or a fluororesin powder, wherein the spray material powder comprises at least one of a titanium powder, a titanium alloy powder, an iron powder, a stainless steel powder, a cast iron powder, a copper alloy powder, an aluminum alloy powder, a nickel powder, and a nickel alloy powder.

3. The non-stick coating of claim 1, wherein the volume ratio of the non-stick powder to the carbon fluoride powder in the composite powder is 3:1 to 10: 1.

4. The non-stick coating of claim 1, wherein the non-stick powder has a particle size of 5 μm to 15 μm, the carbon fluoride powder has a particle size of 10 μm to 50 μm, and the ratio of the particle sizes of the carbon fluoride powder and the non-stick powder is 2:1 to 10:1,

wherein the particle size of the composite powder is 20-100 μm.

5. A non-stick coating formed from a composite powder having a particle form, each particle comprising a non-stick powder and a powder of a carbon fluoride material, the powder of the carbon fluoride material being doped in the non-stick powder by a binder, wherein the carbon fluoride material comprises graphite fluoride and/or graphene fluoride, and the mass fraction of fluorine atoms in the carbon fluoride material is 30% to 61%.

6. The non-stick coating of claim 5, wherein the non-stick powder comprises a spray material powder or a fluororesin powder, wherein the spray material powder comprises at least one of a titanium powder, a titanium alloy powder, an iron powder, a stainless steel powder, a cast iron powder, a copper alloy powder, an aluminum alloy powder, a nickel powder, and a nickel alloy powder,

the binder includes at least one of a cellulose-based binder and an alcohol-based binder.

7. The non-stick coating of claim 6, wherein the volume ratio of the non-stick powder to the carbon fluoride powder in the composite powder is 2:1 to 6: 1.

8. The non-stick coating of claim 7 wherein the volume ratio of the non-stick powder, the carbon fluoride material, and the binder is (20-30): (5-10): (1-2).

9. The non-stick coating of claim 6, wherein the non-stick powder and the fluorocarbon powder each have a particle size in the range of 10 μm to 40 μm, and the fluorocarbon powder and non-stick powder have a particle size ratio of 1:2 to 3: 2; the particle diameter of the composite powder is 20-100 μm.

10. Cookware, characterized in that it comprises a cookware base and a non-stick coating according to any of claims 1 to 4 or according to any of claims 5 to 9, formed by means of cold spraying.