Cookware and preparation method thereof

Abstract

The present application provides a cookware and a method for preparing the same. The cookware comprises: a cookware base; a non-stick coating formed on the inner surface of the cookware base, wherein the non-stick coating is formed of a composite material comprising an amorphous alloy and a porous ceramic material, wherein the composite material is particles of an amorphous alloy coated on the surface of the porous ceramic material. According to the solution of the present application, the non-stick coating formed by the composite material also has good wear resistance and long-lasting non-stick properties.

Description

Technical Field

[0001] The present application relates to the technical field of kitchenware, and more specifically, to a cookware and a preparation method thereof. Background Art

[0002] When cooking, non-stick pans will not get food stuck to the bottom of the pan, which avoids the phenomenon of food sticking to the pan that often occurs in traditional pans during cooking, thus avoiding the problem of food burning and the generation of harmful substances caused by burning. Non-stick pans not only reduce the difficulty of cleaning the pans, but also make it easy to fry and stir-fry food, avoiding the need for more grease in traditional pans to prevent food from sticking to the pan, minimizing the use of oil, reducing the user's fat intake, and conforming to the modern people's pursuit of low-fat, low-calorie consumption trends. Therefore, non-stick pans have become the first choice for many families.

[0003] The cookware on the market mainly achieves the non-stick effect by coating with a non-stick layer, among which ceramic coating and silicone resin coating are the more common non-stick layers. Although both ceramic coating and silicone resin coating can be used as the non-stick layer of cookware, there are obvious problems during use. For example, the non-stick layer formed by ceramic coating has poor non-stick properties and is easy to fall off after 3 to 6 months of use; while the non-stick layer formed by silicone resin coating is easy to turn yellow or gray under high temperature or open flame conditions, and the hardness of the non-stick layer decreases at high temperature, which is easy to produce "re-sticking" phenomenon. Summary of the invention

[0004] In order to solve one or more of the above problems, the present invention provides a cookware with good non-stick and long-lasting non-stick properties and a simple preparation process.

[0005] An embodiment of the first aspect of the present application provides a cookware, which includes: a cookware base; a non-stick coating formed on the inner surface of the cookware base, wherein the non-stick coating is formed by a composite material including an amorphous alloy and a porous ceramic material, wherein the composite material is particles of an amorphous alloy coated on the surface of the porous ceramic material, and the porous ceramic material is 5% to 30% of the sum of the mass of the amorphous alloy and the porous ceramic material.

[0006] A granular composite material comprising an amorphous alloy and a porous ceramic material is used to form a non-stick coating on the inner surface of the cookware. The formed non-stick coating retains the amorphous structure in the amorphous alloy to a large extent, and at the same time retains the pore structure in the porous ceramic material to the greatest extent. Therefore, the non-stick coating utilizes the low surface energy characteristics of the amorphous structure and the oil absorption and oil film formation characteristics of the porous material to achieve the non-stick nature of the cookware, and the formed non-stick coating has good wear resistance and long-lasting non-stick properties.

[0007] In some embodiments, the non-stick coating has an amorphous phase ratio of 60% to 100%, and a porosity of 20% to 40%. The amorphous phase ratio in the non-stick coating ensures that the non-stick coating will not stick during use, and at the same time can reduce the requirements for the spraying process. The porosity of the non-stick coating is conducive to the non-stick coating absorbing oil to form an oil film, which to a certain extent enhances the non-stick performance brought by the low surface energy of the amorphous phase.

[0008] In some embodiments, the porous ceramic material includes at least one of diatomaceous earth, zeolite powder and bentonite; the amorphous alloy includes at least one of Fe-based amorphous alloy, Zr-based amorphous alloy, Cu-based amorphous alloy, Al-based amorphous alloy, Mg-based amorphous alloy, Ti-based amorphous alloy and equiatomic ratio high entropy amorphous alloy.

[0009] In some embodiments, the thickness of the non-stick coating is 100 μm to 500 μm, and the particle size of the granular composite material is 60 to 100 μm. The coating of this thickness has the characteristics of good density and good wear resistance, and can also avoid the problem of heat concentration during the coating preparation process, which causes the amorphous structure to undergo crystallization transformation and causes the non-stick property of the non-stick coating to decrease.

[0010] The second aspect of the present application provides a method for preparing a cookware, comprising: preheating a cookware base; spraying a composite powder on the inner surface of the cookware base to form a non-stick coating on the inner surface of the cookware base, wherein the composite powder comprises an amorphous alloy material and a porous ceramic material, and the porous ceramic material is 5% to 30% of the total mass of the amorphous alloy and the porous ceramic material.

[0011] In some embodiments, the amorphous phase in the non-stick coating accounts for 60% to 100%, and the porosity of the non-stick coating is 20% to 40%.

[0012] In some embodiments, the composite powder is formed by coating porous ceramic powder and amorphous alloy powder, and the amorphous alloy powder is coated on the outer surface of the porous ceramic powder. When the composite powder in which the amorphous alloy powder is coated on the surface of the porous ceramic material powder is sprayed, usually only the amorphous alloy powder on the surface of the composite powder is melted by heat, so as to avoid the porous ceramic material being heated and causing its pore structure to be destroyed, and the composite powder is attached to the inner surface of the cookware substrate together with the melting of the amorphous alloy powder. Therefore, in the coating formed by the composite powder, the pore structure in the porous ceramic material is retained, the porosity of the coating is increased, the coating is conducive to oil absorption to form an oil film, and the non-stickiness of the coating is improved.

[0013] In some embodiments, the particle size of the composite powder is 60-100 μm. The composite powder within this particle size range has good fluidity, is not easy to clog the spray gun during the spraying process, and is convenient for construction.

[0014] In some embodiments, the porous ceramic powder has a particle size of 35-60 μm, and the amorphous alloy powder has a particle size of 10-20 μm. There is a certain particle size difference between the two powders, which is conducive to the amorphous alloy powder coating the outer surface of the porous ceramic powder to form a composite powder.

[0015] In some embodiments, the porous ceramic material includes at least one of diatomite, zeolite powder and bentonite; the amorphous alloy powder includes at least one of Fe-based amorphous alloy powder, Zr-based amorphous alloy powder, Cu-based amorphous alloy powder, Al-based amorphous alloy powder, Mg-based amorphous alloy powder, Ti-based amorphous alloy powder and high-entropy amorphous alloy powder. The high-entropy amorphous alloy can be an equiatomic high-entropy amorphous alloy. DETAILED DESCRIPTION

[0016] The concepts of the present invention will now be described more fully hereinafter.

[0017] There are three main ways that a non-stick pan can achieve non-stick properties: (1) the surface of the pan itself has low surface energy; (2) the surface of the pan is provided with a microscopic concave-convex structure, which forms a hydrophobic and oleophobic surface similar to that of a lotus leaf; (3) the surface of the pan is coated with a porous oil storage material, which can form a stable oil film on the surface of the pan after absorbing edible oil, and the formed oil film makes the pan non-stick.

[0018] Amorphous alloys are also called liquid metals. They have lower surface energy than ordinary materials and show good non-stick properties. Specifically, the amorphous structure of amorphous alloys has the characteristics of long-range disorder and short-range order, so it has lower surface energy. In addition, amorphous alloys do not have structural defects such as grain boundaries, twins, lattice defects, dislocations, stacking faults, etc. like crystalline alloys, nor do they have heterogeneous phases, precipitates, segregation, and other component fluctuations. It is a chaotic disordered structure with a high degree of chemical uniformity. When subjected to external forces, there is no plastic deformation such as grain boundary sliding. The inventors also found that porous ceramic materials can store edible oil to form an oil film, and the formed oil film can achieve non-stick cookware.

[0019] In this regard, the inventor first tried to mix amorphous alloy powder and porous ceramic material powder and then directly thermally spray them on the inner surface of the cookware substrate to form a non-stick coating. The non-stick coating uses the characteristics of low surface energy of the amorphous structure and the characteristics of porous ceramic materials to absorb oil to form an oil film to achieve the non-stick effect of the cookware. After testing, the cookware formed thereby has a non-stick effect. However, when further analyzing the non-stick coating, the inventor found that the content of porous material in the non-stick coating was low; and although the amorphous alloy powder and the porous material powder were mixed at the same mass ratio during spraying, the content of porous material in the non-stick coating formed by each spraying was different. The reason is that the density and melting point of the porous material and the amorphous alloy are different. If the two powders are directly thermally sprayed after mixing, the porous material powder with low density and higher melting point has a low deposition rate during the thermal spraying process, while the amorphous alloy powder with high density and low melting point has a high deposition rate, which ultimately leads to the uncontrollable ratio of amorphous alloy and porous material in the coating.

[0020] Based on this, the inventors coated amorphous alloy powder on the outer surface of porous ceramic material powder to form a composite powder with a core-shell structure, thereby utilizing the characteristics of amorphous alloys that have higher density and lower melting point than porous ceramic materials. During thermal spraying, the porous ceramic material is deposited on the inner surface of the cookware substrate together with the molten amorphous alloy. In this way, not only the deposition rate of the porous material is improved, but also the mass ratio of the amorphous alloy and the porous ceramic material in the non-stick coating can be controlled. After testing, the non-stick coating on the surface of the cookware has better non-stick effect and lasting non-stick property.

[0021] According to the present application, the composite powder can be prepared by a coating process, such as a spray granulation process. The preparation of the composite powder is described below using the spray granulation process as an example, which specifically includes the following steps.

[0022] (1) Prepare raw material powders by uniformly mixing amorphous alloy powder and porous ceramic powder.

[0023] Specifically, the amorphous alloy powder and the porous ceramic powder are respectively put into a ball mill for ball milling. The porous ceramic powder can be selected from at least one of diatomaceous earth powder, zeolite powder and bentonite with a purity higher than 99.5%. After ball milling, the particle size of the amorphous alloy powder is 10-20 μm, and the particle size of the porous ceramic powder is 35-60 μm. There is a certain particle size difference between the two powders after ball milling, which is conducive to the formation of a core-shell structure during the coating process. The porous ceramic powder and the amorphous alloy powder after ball milling are then fully mixed to obtain a raw material powder, wherein the mass ratio of the porous ceramic powder is 5% to 30% based on the total mass of the raw material powder; the mass difference between the porous ceramic powder and the amorphous alloy powder within this mass ratio range is large, which can ensure that there is enough amorphous alloy powder coated on the outer surface of the porous ceramic powder during the spray granulation process.

[0024] (2) Prepare slurry by fully mixing raw material powder, binder and solvent to obtain slurry; in addition, auxiliary agents and fillers may also be added.

[0025] Based on the total mass of the slurry, the mass fraction of the raw material powder in the slurry can be 30% to 60%, preferably 40% to 50%; the mass fraction of the binder in the slurry can be 1% to 10%, preferably 3% to 8%; the mass fraction of the auxiliary agent in the slurry can be 0.2% to 1%; the mass fraction of the filler in the slurry can be 5% to 20%, preferably 8% to 15%; the mass fraction of the solvent in the slurry can be 20% to 60%, preferably 40% to 55%.

[0026] When preparing the slurry, the binder is mainly used to bind the raw material powder and filler in the slurry together to avoid the composite powder formed by spray granulation from being too small or unable to form a core-shell structure. The binder can be selected from polyvinyl alcohol, polyvinyl pyrrolidone or sodium carboxymethyl cellulose. The additives include defoamers and dispersants, which can be mixed in any ratio, wherein the defoamer is mainly used to eliminate bubbles or foam in the slurry, and the dispersant is mainly used to evenly disperse the components in the slurry. The defoamer can be an organic silicone oil or a polyether-modified silicone oil, such as dimethyl silicone oil, and the dispersant can be citric acid or triethylhexyl phosphoric acid. The filler is used to adjust the viscosity of the slurry and slow down the sedimentation of the amorphous alloy powder in the slurry. The filler can be graphite powder or carbon black powder. The solvent is used as a medium to facilitate the mixing of raw material powder, binder, additive, filler and solvent to form a slurry. The solvent can be anhydrous ethanol, acetone or deionized water.

[0027] (3) Spray granulation to obtain composite powder.

[0028] First, the prepared slurry is atomized to form droplets, and the droplet-shaped slurry is dried to obtain a composite powder. As an example, the slurry can be spray-dried under the following conditions: atomization in an inert atmosphere, specifically, using 99.999% argon atmosphere, an atomization pressure of 0.3 to 0.6 MPa, preferably 0.4 to 0.5 MPa; an atomization gas flow rate of 0.5 to 5 m 3 / h, preferably 1.0 to 3.0 m 3 / h; the air inlet temperature is 60-100°C, preferably 80-100°C; the air outlet temperature is 100-150°C, preferably 120-150°C. However, the bonding strength between the amorphous alloy and the ceramic material in the composite powder obtained by spray drying is not stable enough. Therefore, according to the method of the present invention, the composite powder can be further sintered. The sintering temperature is increased according to the physical property curve of the composite powder. The sintering conditions can be: sintering at 50-200°C in the low temperature zone and keeping warm for 15-30 minutes, and then sintering at 200-600°C in the high temperature zone and keeping warm for 2-4 hours.

[0029] (4) The composite powder prepared above is sieved to obtain composite powders of different particle sizes. Finally, powder particles with a particle size of 60 to 100 μm are selected as composite powders for spraying onto the cookware substrate.

[0030] In addition, the amorphous alloy powder in the present application can be prepared by an atomization powder making method of an amorphous alloy. The preparation of the amorphous alloy powder is described by taking Fe-based amorphous alloy powder as an example, and the atomization preparation method thereof is described as follows.

[0031] First, the molten Fe-based amorphous alloy is sprayed onto a copper quenching plate that rotates at a high speed (the surface linear speed can reach 100m / s). Under the action of centrifugal force, the molten Fe-based amorphous alloy is atomized and solidified into fine particles, which will spread out in all directions, and inert gas is sprayed through gas nozzles installed around the plate to accelerate cooling. When using this method to prepare amorphous alloy powder, the cooling rate of the molten amorphous alloy can reach 106K / s, so that the molten amorphous alloy solidifies in a supercooled state before it has time to crystallize, forming an amorphous alloy powder with an amorphous structure.

[0032] The above-mentioned method for preparing Fe-based amorphous alloy powder is also applicable to the preparation of other amorphous alloy powders.

[0033] The following is a description of a method for preparing a cookware provided in the first aspect of the present application by thermally spraying the composite powder prepared above on the surface of a cookware substrate. The method for preparing the cookware specifically comprises the following steps:

[0034] Step S110: pre-treating the surface of the cookware base;

[0035] Step S120: preheating the cookware base;

[0036] Step S130: spraying the composite powder prepared by spray granulation onto the inner surface of the cookware base to form a non-stick coating.

[0037] Step S140: sanding the surface formed with the non-stick coating, and the surface roughness Ra of the coating after sanding is 1-2 μm.

[0038] The purpose of treating the substrate surface in step S110 is mainly to improve the bonding force between the non-stick coating and the cookware substrate. The surface treatment of the cookware substrate may include cleaning and sandblasting. The cleaning step may remove the oil stains on the surface of the substrate, such as cleaning the surface of the substrate with an alkaline solvent, and the alkaline solvent may be a diluted sodium hydroxide solution. Sandblasting may increase the roughness of the substrate surface, which is conducive to the non-stick coating being firmly attached to the cookware substrate. The surface roughness Ra of the cookware substrate after sandblasting is 2 to 5 μm.

[0039] In step S120, the cookware base is preheated in a heating furnace. The purpose of preheating is to reduce the temperature difference between the cookware base and the sprayed composite powder, reduce the thermal stress between the cookware base and the non-stick coating, thereby improving the quality of the non-stick coating and the bonding strength between the non-stick coating and the cookware base. As an example, the preheating temperature of the cookware base can be 200-300°C.

[0040] In step S130, a plasma spraying process may be used. In the plasma spraying process, the cookware may be placed in a spraying chamber, and the spraying chamber may be evacuated to a certain vacuum, and then filled with argon gas for protection to prevent the amorphous alloy from being oxidized during the spraying process and causing impurities to be introduced into the formed coating; the composite powder may then be plasma sprayed on the inner surface of the preheated cookware substrate, and finally a cookware with a non-stick coating may be obtained.

[0041] As an example, the spray chamber is evacuated to a vacuum of 3 Pa and filled with argon gas to 6 × 10 3 Pa; the conditions of the plasma spraying process are: transferred arc power 30Kw, arc current 600A~800A, spraying distance 120mm, spraying angle 60°~80°, powder feeding speed: 10~40g / min, hydrogen pressure: 0.3~0.7MPa, flow rate 5~10L / min.

[0042] In addition, since the composite powder obtained by granulation has a core-shell structure, in step S130, the amorphous alloy layer on the surface of the composite powder is heated and melted during plasma spraying, thereby preventing the porous ceramic material from being heated and causing its pore structure to be destroyed, and the amorphous alloy is attached to the surface of the cookware substrate together with the amorphous alloy. In addition, by coating the amorphous alloy powder on the outer surface of the porous ceramic to form coated particles before spraying, the problem of low deposition rate due to the low density and high melting point of the porous ceramic material is avoided. Therefore, in the coating formed by spraying the above-mentioned composite powder, the deposition rate of the porous ceramic material is ensured, and the pore structure in the porous ceramic material is retained, which increases the porosity of the coating, facilitates the coating to absorb oil to form an oil film, and achieves the non-stickiness of the coating.

[0043] In addition, the particle size of the composite powder used in plasma spraying is 60 to 100 μm. The composite powder within this particle size range has good fluidity and is not easy to clog the spray gun during the plasma spraying process, which facilitates construction.

[0044] In some embodiments, the porous ceramic material may include at least one of diatomaceous earth, zeolite powder and bentonite, however, the present application is not limited thereto, and those skilled in the art may select other porous ceramic materials under the guidance of the present application. The amorphous alloy powder may include one of Fe-based amorphous alloy powder, Zr-based amorphous alloy powder, Cu-based amorphous alloy powder, Al-based amorphous alloy powder, Mg-based amorphous alloy powder, Ti-based amorphous alloy powder and high-entropy amorphous alloy powder. The high-entropy amorphous alloy may be an equiatomic high-entropy amorphous alloy or an approximately equiatomic high-entropy amorphous alloy.

[0045] The second aspect of the present application provides a cookware, which can be prepared by the first aspect of the embodiment, the cookware comprising: a cookware substrate; a non-stick coating formed on the inner surface of the cookware substrate, the non-stick coating being formed by a composite powder comprising an amorphous alloy and a porous ceramic material through a spraying process, the composite material being particles of an amorphous alloy coated on the surface of a porous ceramic material, and the porous ceramic material being 5% to 30% of the sum of the mass of the amorphous alloy and the porous ceramic material.

[0046] In this embodiment, the non-stick coating formed on the inner surface of the cookware substrate by plasma spraying of the granular composite material retains the amorphous structure in the amorphous alloy to a large extent, and at the same time retains the pore structure in the porous ceramic material to the greatest extent. Therefore, the formed non-stick coating not only has the low surface energy of the amorphous structure, which makes the coating have a non-stick effect; it also has the characteristics of porous ceramic materials absorbing oil and forming an oil film on the surface of the non-stick coating. The formed oil film strengthens the non-stick property generated by the low surface energy of the amorphous alloy, further improving the non-stick effect of the non-stick coating. The particle size of the granular composite material in this embodiment can be 60 to 100 μm.

[0047] In addition, the uniform distribution of porous ceramic materials in the formed non-stick coating is conducive to forming a uniform oil film on the surface of the non-stick coating, thereby improving the non-stick effect of the non-stick coating; secondly, the uniform distribution of porous ceramic materials is conducive to uniform heating of the non-stick coating, which can avoid inconsistent thickness of the non-stick coating due to uneven distribution of porous ceramic materials, ultimately causing the non-stick coating to be locally too thin and ablated during use.

[0048] In addition, porous ceramic materials have better wear resistance and high melting point, which can prevent the porous ceramic materials from melting due to excessively high temperatures during thermal spraying, causing damage to the pore structure and enhancing the wear resistance of the coating; secondly, the good wear resistance of porous ceramic materials can prevent the formed non-stick coating from having its pore structure destroyed due to wear during use, resulting in the inability to absorb oil to form an oil film, and porous ceramic materials with good wear resistance extend the service life of the non-stick coating.

[0049] In addition, since amorphous alloys do not have structural defects such as grain boundaries, twins, lattice defects, dislocations, stacking faults, etc. like crystalline alloys, and do not have heterogeneous phases, precipitates, segregation and other composition fluctuations, they are highly chemically uniform and do not experience plastic deformation such as grain boundary sliding when subjected to external forces. They have higher strength, thus further enhancing the wear resistance of the non-stick coating and making the coating on the surface of the cookware produce long-lasting non-stick properties.

[0050] In some embodiments, the amorphous phase in the non-stick coating accounts for 60% to 100%, and the porosity of the non-stick coating is 20 to 40%. The 60% to 100% amorphous phase in the non-stick coating ensures that the formed non-stick coating will not stick during use, and at the same time can also reduce the requirements for the plasma spraying process. The 20% to 40% porosity of the non-stick coating is conducive to the non-stick coating absorbing oil to form an oil film, which to a certain extent strengthens the non-stick performance brought by the low surface energy of the amorphous phase. The porosity in this implementation includes the 2% to 10% porosity generated by the thermal spraying process and the porosity of the porous ceramic material itself. The porosity generated by the thermal spraying process is controlled at 2 to 10%, which can ensure the strength and wear resistance of the formed non-stick coating, and at the same time has a certain oil absorption effect; and because the pores of the porous ceramic material itself are its inherent structure, the porosity caused by the pore structure of the porous ceramic material will not affect the strength of the non-stick coating. Therefore, by adding porous ceramic materials, the porosity of the coating can be within the range of 20% to 40%. On the one hand, the strength of the coating can be ensured, and on the other hand, the porosity of the coating can be increased, which is beneficial for the coating to store oil and form an oil film, thereby improving the non-stickiness of the coating.

[0051] In some embodiments, the amorphous alloy is one or more of Fe-based amorphous alloy, Zr-based amorphous alloy, Cu-based amorphous alloy, Al-based amorphous alloy, Mg-based amorphous alloy, Ti-based amorphous alloy and high entropy amorphous alloy. In the present application, when there are multiple amorphous alloys, the alloys can be mixed at any value. The main element components of the above-mentioned amorphous alloy include: at least one of Fe, Zr, Cu, Al, Mg and Ti, and other elements may include at least one of Sn, Ni, Pb, Zn, Nd, Ga, Mo, Hf, Cr, Ca, Y, Si, P, B and C. According to some embodiments of the present application, the Zr-based amorphous alloy may be Zr60-Cu23-Al10-Ni5-Hf2 or Zr65-Ti-Ni10-Al10-Cu15; the Fe-based amorphous alloy may be Fe80-Cr5-Mo6-B4-Si5, Fe50-Zr20-Cr9-B6-Cu10-Y5, Fe87.4-Si6.7-B2.4-Cr2.7-C0.8, Fe90-B7-Si3; the high-entropy amorphous alloy may be an equiatomic ratio high-entropy amorphous alloy, such as Fe-Sn-Pb-PC.

[0052] According to an embodiment of the present invention, a plasma thermal spraying process can be used to spray the composite powder onto the surface of the cookware substrate to form a non-stick coating. In some embodiments, the thickness of the formed non-stick coating is 100-500 μm. It can be formed by multiple spraying, for example, each spraying thickness is 30-50 μm. When the thickness of the non-stick coating is less than 100 μm, it is usually only necessary to spray 1 to 2 layers of composite materials during thermal spraying to form it. The thermal spraying ions will no longer be continued to compact the deposited non-stick coating, resulting in less deformation of the deposited particles under stress, and the density of the formed non-stick coating is poor. It is loose and porous in structure, which ultimately leads to poor strength and insufficient wear resistance of the non-stick coating. If the thickness of the coating is greater than 500 μm, the thermal spraying preparation will cause heat concentration in the coating, prompting the crystallization transformation of part of the amorphous structure in the amorphous alloy, reducing the proportion of amorphous phase in the non-stick coating, and ultimately causing the non-stick property of the non-stick coating to decrease.

[0053] Example

[0054] The preparation of the cookware in this application is described in detail below by taking the Fe-based amorphous alloy powder as Fe50-Zr20-Cr9-B6-Cu10-Y5 alloy powder and the porous ceramic material as diatomaceous earth as an example.

[0055] Example 1

[0056] The preparation method of the composite powder specifically comprises the following steps:

[0057] Step 210: First, Fe50-Zr20-Cr9-B6-Cu10-Y5 alloy powder and diatomaceous earth with a purity higher than 99.5% are respectively put into a ball mill for ball milling. After ball milling, the particle size of the Fe50-Zr20-Cr9-B6-Cu10-Y5 alloy powder is 10-13 μm, and the particle size of the diatomaceous earth is 40-42 μm; then the ball-milled Fe50-Zr20-Cr9-B6-Cu10-Y5 alloy powder and diatomaceous earth are mixed to obtain a raw material powder, wherein the mass proportion of the Fe50-Zr20-Cr9-B6-Cu10-Y5 alloy powder is 94%, and the mass proportion of the diatomaceous earth is 6%.

[0058] Step 220: The raw material powder, the binder, the auxiliary agent, the filler and the solvent are fully mixed to obtain a slurry; wherein the mass fraction of the raw material powder is 42%; the binder is polyvinyl alcohol, and its mass fraction is 5%; the auxiliary agent is dimethyl silicone oil and citric acid, and the dimethyl silicone oil and citric acid are mixed in a mass ratio of 1:1, and the mass fraction of the auxiliary agent is 0.5%; the filler is carbon black, and its mass fraction is 11%; the solvent is deionized water, and its mass fraction is 41.5%.

[0059] Step 230: First, the slurry is atomized to form droplets, and the droplet-shaped slurry is dried to obtain a composite powder. The conditions for spray drying the slurry are: atomization in an argon atmosphere, an atomization pressure of 0.5 MPa, and an atomization gas flow rate of 2.8 m 3 / h, the air inlet temperature is 80℃, and the air outlet temperature is 120℃; the water in the atomized droplets is evaporated to obtain a composite powder. In order to further improve the bonding strength of the amorphous alloy and the ceramic material in the composite powder, the composite powder is further sintered. The sintering conditions of the composite powder are: sintering at 180℃ in the low temperature zone and keeping warm for 30min, and sintering at 480℃ in the high temperature zone and keeping warm for 3h.

[0060] Step 240: Screening the composite powder obtained in step 230 to screen out composite powder with a particle size between 80 and 86 μm.

[0061] The composite powder obtained in this example is sprayed on the surface of the cookware substrate to form a non-stick coating on the cookware substrate.

[0062] The preparation method of the cookware specifically comprises the following steps:

[0063] Step 310: Pre-treating the surface of the cookware base

[0064] Firstly, the oil stains on the surface of the cookware substrate were cleaned with a cleaning agent solution mainly composed of 0.8% NaOH solution, 15% sodium carbonate solution and 15% sodium metasilicate, and then the surface of the cleaned cookware substrate was sandblasted to obtain a cookware substrate with a surface roughness Ra of 3 μm.

[0065] Step 320: Preheating the cookware base

[0066] The surface-pretreated cookware substrate is preheated to 280° C. in a heating furnace.

[0067] Step 330: Plasma Spraying

[0068] During the plasma spraying process, the pot can be placed in the spraying chamber first, and then the spraying chamber is evacuated to a vacuum degree of 3Pa, and then argon gas is injected into the spraying chamber to a pressure of 6×10 3 Pa; finally, under the conditions of transferred arc power of 30KW, arc current of 700A, spraying distance of 120mm, spraying angle of 75°, powder feeding speed of 25g / min, hydrogen pressure of 0.6MPa and hydrogen flow rate of 8L / min, the composite powder was sprayed on the preheated cookware substrate to form a non-stick coating; wherein, the composite powder was prepared in Example 1, and the thickness of the obtained non-stick coating was 250μm.

[0069] Step 340: Subsequent treatment of non-stick coating

[0070] The non-stick coating obtained in step 330 is naturally cooled, and then the surface of the non-stick coating is sanded with 120-grit sandpaper. After sanding, the surface roughness Ra is 2 μm, and a non-stick cookware is obtained.

[0071] Example 2

[0072] The composite powder was prepared according to the method described in the above embodiment 1, except that the mass proportion of diatomaceous earth in the raw material powder in step 110 was 15%, and then the cookware was prepared according to the method described in the above embodiment 1.

[0073] Example 3

[0074] The composite powder is prepared according to the method described in the above embodiment 1, except that the mass proportion of diatomaceous earth in the raw material powder in step 110 is 25%, and then the cookware is prepared according to the method described in the above embodiment 1.

[0075] Comparative Example 1

[0076] The composite powder was prepared according to the method described in the above embodiment 1, except that the mass percentage of diatomaceous earth in the raw material powder in step 110 was 2%, and then the cookware was prepared according to the method described in the above embodiment 1.

[0077] Comparative Example 2

[0078] The composite powder is prepared according to the method described in the above embodiment 1, except that the mass proportion of diatomaceous earth in the raw material powder in step 110 is 50%, and the cookware is prepared according to the method described in the above embodiment 1.

[0079] Comparative Example 3

[0080] The raw powder is obtained by mixing Fe50-Zr20-Cr9-B6-Cu10-Y5 alloy powder with a particle size of 10-13 μm after ball milling and diatomaceous earth with a particle size of 40-42 μm. The obtained raw powder is directly plasma sprayed to form a non-stick coating, and the mass proportion of diatomaceous earth in the raw powder is 6%. The cookware is prepared according to the method described in the above Example 1.

[0081] Comparative Example 4

[0082] The cookware is prepared according to the method described in the above embodiment 1, except that amorphous alloy powder with a particle size of 10-13 μm is selected during plasma spraying in step 330 .

[0083] Comparative Example 5

[0084] The cookware is prepared according to the method described in the above embodiment 1, except that diatomaceous earth with a particle size of 40-42 μm is selected during plasma spraying in step 330 .

[0085] Performance index test

[0086] 1. The cookware obtained in the above-mentioned Examples 1 to 3 and Comparative Examples 1 to 4 was subjected to performance tests, and the test results were recorded in Table 1. Specifically, the following tests were performed on the cookware:

[0087] (1) Porosity testing of non-stick coatings in cookware

[0088] In the present application, the porosity of the non-stick coating on the cookware is measured by observing the sample cross section with a metallographic microscope, and then setting different contrasts to measure the porosity using IQmeterial software.

[0089] (2) Strength test of non-stick coating on cookware

[0090] A 500g steel ball is dropped vertically from a height of 50cm and hits the inner surface of the cookware. If the non-stick coating does not crack, break or fall off, it is qualified; otherwise it is unqualified.

[0091] (3) Wear resistance test of non-stick coating on cookware

[0092] The wear resistance test of the non-stick coating on the surface of the cookware in this application is carried out with reference to GB / T32095.2-2015, and the number of times the non-stick coating is worn through and the bottom is exposed is recorded.

[0093] (4) Test on the long-lasting non-stick properties of non-stick coatings on cookware

[0094] In the present application, the long-lasting non-stick test of the non-stick coating on the surface of the cookware is to add a step to the wear resistance test, in which a fried egg test is performed every 1000 frictions, and the corresponding number of frictions when "bad (X)" appears for two consecutive fried eggs is recorded.

[0095] Table 1 Performance index test results

[0096]

[0097] As can be seen from Table 1, in the present application, a composite material in which a granular amorphous alloy is coated on the surface of a porous ceramic material is formed into a non-stick coating by plasma spraying, so that the formed cookware has good non-stick effect, lasting non-stick property and wear resistance.

[0098] It can be seen from the test results in Example 1 and Comparative Example 3 that the non-stick coating formed by thermal spraying the composite powder formed by granulation has a larger porosity, better wear resistance and lasting non-stick property than the non-stick coating formed by directly mixing the two powders.

[0099] It can be seen from the test results of Examples 1 to 3 and Comparative Example 2 that when the mass proportion of the porous ceramic powder in the raw material powder is too large, the coating formed by spraying the composite powder formed by granulation has a large porosity, good wear resistance and lasting non-stickiness, but the strength of the formed non-stick coating is insufficient, resulting in a shortened service life of the non-stick coating.

[0100] It can be seen from Example 1 and Comparative Example 1 that when the mass proportion of porous ceramic material in the raw material powder is greater than 6%, the wear resistance and long-term non-stick effect of the non-stick coating formed by thermal spraying of the composite powder obtained by granulation are significantly improved. From the test results of Examples 1 to 3 and Comparative Examples 4 to 5, it is found that the non-stick coating formed only by amorphous alloy has low porosity, poor long-term non-stick and wear resistance, and the non-stick coating formed only by porous ceramic material cannot be used at all.

[0101] The specific implementation methods of the present application are described in detail above. Although some embodiments have been shown and described, those skilled in the art should understand that these embodiments may be modified and improved (for example, different features described in different embodiments may be combined) without departing from the principles and spirit of the present application, the scope of which is defined by the claims and their equivalents, and these modifications and improvements should also be within the scope of protection of the present application.

Claims

1. A cookware, characterized in that: include: Cookware base; The non-stick coating is formed on the inner surface of the cookware substrate. The non-stick coating is formed by a composite material including an amorphous alloy and a porous ceramic material. The composite material is a particle with a core-shell structure in which an amorphous alloy powder is coated on the surface of the porous ceramic material.

2. The cookware according to claim 1, characterized in that: The porous ceramic material is 5% to 30% of the total mass of the amorphous alloy and the porous ceramic material, the amorphous phase in the non-stick coating accounts for 60% to 100%, and the porosity of the non-stick coating is 20% to 40%.

3. The cookware according to claim 1, characterized in that: The porous ceramic material includes at least one of diatomaceous earth, zeolite powder and bentonite; the amorphous alloy includes at least one of Fe-based amorphous alloy, Zr-based amorphous alloy, Cu-based amorphous alloy, Al-based amorphous alloy, Mg-based amorphous alloy, Ti-based amorphous alloy and high-entropy amorphous alloy.

4. The cookware according to claim 1, characterized in that: The thickness of the non-stick coating is 100 μm to 500 μm, and the particle size of the granular composite material is 60 μm to 100 μm.

5. A method for preparing a cookware, characterized in that: include: Preheat the pot base; The composite powder is sprayed on the inner surface of the cookware substrate to form a non-stick coating, wherein the composite powder is a particle with a core-shell structure in which an amorphous alloy powder is coated on the surface of a porous ceramic material.

6. The preparation method according to claim 5, characterized in that: The porous ceramic material is 5% to 30% of the total mass of the amorphous alloy and the porous ceramic material.

7. The preparation method according to claim 6, characterized in that: The amorphous phase in the non-stick coating accounts for 60% to 100%, and the porosity of the non-stick coating is 20% to 40%.

8. The preparation method according to claim 7, characterized in that: The particle size of the composite powder is 60 μm to 100 μm.

9. The preparation method according to claim 7, characterized in that: The particle size of the porous ceramic material is 35 μm to 60 μm, and the particle size of the amorphous alloy powder is 10 μm to 20 μm.

10. The preparation method according to claim 7, characterized in that: The porous ceramic material includes at least one of diatomaceous earth, zeolite powder and bentonite; The amorphous alloy powder includes at least one of Fe-based amorphous alloy powder, Zr-based amorphous alloy powder, Cu-based amorphous alloy powder, Al-based amorphous alloy powder, Mg-based amorphous alloy powder, Ti-based amorphous alloy powder and high entropy amorphous alloy powder.

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