Method for manufacturing cookware and cookware

Abstract

The present application provides a method for manufacturing cookware and the cookware. The method for manufacturing cookware includes forming a non-stick coating comprising a metal material on a cookware substrate; performing a micro-arc oxidation treatment on the cookware substrate having the non-stick coating, so that at least a portion of the metal in the metal material of the surface layer of the non-stick coating is oxidized into metal oxide, and at least an amorphous oxide layer with a preset thickness is formed on the surface layer of the non-stick coating by the metal oxide, and the surface of the amorphous oxide layer serves as the inner surface of the cookware. According to the present application, the surface layer of the non-stick coating serving as the inner surface of the cookware is an oxide layer with a preset thickness and an amorphous phase, so that the cookware can improve its non-stick properties due to its low surface energy, and thus the pores or depressions in the coating are not easy to harbor dirt and grime, thereby improving the visual experience of the cookware during use, and the oxide layer is not easy to change color during use, thereby further improving the visual experience of the cookware during use.

Description

Technical Field

[0001] The present application relates to the field of cookware, and in particular, to a method for manufacturing a cookware and the cookware. Background Art

[0002] Coating-free nonstick technology, which uses a single metal or alloy to create a coating for cookware, offers significant advantages in the cookware manufacturing field. For example, the coating is made from a single metal or alloy that meets food hygiene standards, and no organic coatings are used in the production process. Consequently, the resulting cookware is highly recognized for its safety.

[0003] While uncoated nonstick technology offers certain advantages, the nonstick properties of the coatings created by this technology are limited and difficult to meet user needs. Therefore, improving the nonstick properties of cookware is extremely important in this era of fierce product competition. Furthermore, existing single-element metal or alloy materials that meet food hygiene standards and can be used in uncoated technology are generally light-colored, such as silver-white. The coatings on cookware are prone to discoloration during use due to oxidation or due to the absorption of dirt in gaps or recesses (e.g., from burnt food), resulting in a poor visual experience during use. Summary of the Invention

[0004] Therefore, the purpose of the present application is to provide a method for manufacturing a cookware and a cookware, so as to solve the problem of discoloration of the cookware made by the non-coating non-stick technology during use and the problem of poor non-stick properties of the cookware.

[0005] According to a first aspect of the present application, a method for manufacturing cookware is provided, wherein the method for manufacturing cookware includes forming a non-stick coating comprising a metal material on a cookware substrate; performing micro-arc oxidation treatment on the cookware substrate having the non-stick coating, so that at least a portion of the metal in the metal material of the surface layer of the non-stick coating is oxidized into metal oxide, and an amorphous oxide layer having a preset thickness is formed on the surface layer of the non-stick coating by at least the metal oxide, and the surface of the amorphous oxide layer serves as the inner surface of the cookware.

[0006] In an embodiment, the step of performing micro-arc oxidation treatment on the cookware substrate having the non-stick coating includes providing an electrolyte comprising at least silicate; placing the cookware substrate having the non-stick coating in the electrolyte at a preset temperature and maintaining it for a preset time, so that the silicate in the electrolyte generates an amorphous silicon dioxide film, and the amorphous silicon dioxide film penetrates into the metal oxide and together forms the amorphous oxide layer.

[0007] In an embodiment, the step of forming the non-stick coating comprising a metal material on the cookware substrate comprises spraying at least one of a metal element and an alloy on the cookware substrate, thereby forming the non-stick coating comprising the metal material.

[0008] In an embodiment, the alloy is an amorphous alloy, the non-stick coating is a thermal spray coating having a rough surface structure formed by plasma spraying, the thermal spray coating includes core particles having an amorphous structure and outer coating particles having a crystalline structure located on the surface of the core particles, and the crystalline structure of the outer coating particles can be transformed into an amorphous structure after micro-arc oxidation treatment.

[0009] In an embodiment, the alloy is at least one of a binary amorphous alloy, a ternary amorphous alloy and a high entropy amorphous alloy; or the alloy is a binary alloy formed by at least two metals of Mg, Al, Ti, Zr, Nb and Ta.

[0010] In an embodiment, the metal element includes at least one of Mg, Al, Ti, Zr, Nb and Ta.

[0011] In an embodiment, the binary amorphous alloy includes two main metal elements whose atomic percentages sum to 100% and the balance of secondary non-metal elements, and the atomic percentage of any one of the two main metal elements is above 10%; wherein, the two main metal elements include two of Mg, Al, Ti, Zr, Nb and Ta, and the secondary non-metal elements include at least one of C, N, O, B, S and P; or the two main metal elements include one of Mg, Al, Ti, Zr, Nb and Ta, and also include one of V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Y, Mo, Tc, In, Sn, Sb, Hf and W, and the secondary non-metal elements include at least one of C, N, O, B, S and P.

[0012] In an embodiment, the cookware substrate includes one of an aluminum substrate, an iron substrate, a magnesium substrate, a stainless steel substrate, a titanium substrate, and a composite substrate formed between the above substrates.

[0013] In an embodiment, the method for manufacturing cookware further comprises: before the step of forming the non-stick coating, forming a transition layer on the surface of the cookware base using a corrosion-resistant material, wherein the non-stick coating is formed on the surface of the transition layer.

[0014] In an embodiment, the corrosion-resistant material is at least one of aluminum oxide, titanium oxide, zirconium oxide and titanium suboxide.

[0015] According to a second aspect of the present application, a cookware is provided, wherein the cookware includes a cookware base and a coating formed on the surface of the cookware base, the surface layer of the coating includes an amorphous oxide layer of a preset thickness, the amorphous oxide layer is formed by metal oxide, and the metal oxide is formed by micro-arc oxidation of a metal material. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above and / or other features and aspects of the present invention will become clear and easily understood through the description of the embodiments in conjunction with the accompanying drawings.

[0017] Figure 1 FIG. 4 shows an XRD pattern of a non-stick coating having an amorphous oxide layer on its surface according to an embodiment of the present application.

[0018] Figure 2 A schematic diagram of a cookware according to an embodiment of the present application is shown.

[0019] Figure 3 Shown Figure 2 A local enlarged schematic diagram in . DETAILED DESCRIPTION

[0020] The specific implementation methods of the present application are described in detail below. Although some embodiments have been shown and described, it should be understood by those skilled in the art that these embodiments can be modified and improved without departing from the principles and spirit of the present application, the scope of which is defined by the claims and their equivalents.

[0021] In the uncoated non-stick technology, the coating formed on the cookware is mostly light-colored, for example, silver-white. During the use of the cookware, the surface is easily oxidized and discolored, or the gaps in the cookware are prone to dirt and grime (for example, burnt food and dirt), which makes the visual experience of the cookware poor.

[0022] The applicant has discovered that by using a metal material to create a non-stick coating on the inner surface of a cookware base, and then subjecting the cookware base with the non-stick coating to a micro-arc oxidation treatment, an amorphous oxide layer of a predetermined thickness is formed on the surface of the non-stick coating (i.e., from the outside to the inside of the surface), thereby improving the visual experience of the cookware. Specifically, by using the surface of the amorphous oxide layer as the inner surface of the cookware, the metal oxide forming the amorphous oxide layer has a relatively darker color than the corresponding metal material and a stable texture. Therefore, it is less likely to discolor during use, and the darker color can hide some usage defects (non-functional defects), thereby improving the visual experience of the cookware. In addition, the applicant has discovered that when the formed oxide layer is amorphous, it has a lower surface energy than the crystalline oxide layer or the coating formed by the corresponding metal material, thereby improving the non-stick properties of the coating formed therefrom. When the non-stick properties are good, the pores and depressions on the surface are less likely to harbor dirt, which can further improve the visual experience of the cookware.

[0023] According to a first aspect of the present application, a method for manufacturing cookware is provided, wherein the method for manufacturing cookware comprises: forming a non-stick coating comprising a metal material on a cookware substrate; performing micro-arc oxidation treatment on the cookware substrate having the non-stick coating, so that at least a portion of the metal in the metal material of the surface layer of the non-stick coating is oxidized into metal oxide, and an amorphous oxide layer having a preset thickness is formed on the surface layer of the non-stick coating by at least the metal oxide, and the surface of the amorphous oxide layer serves as the inner surface of the cookware.

[0024] In the embodiments of this application, the inner surface of the cookware is the surface that comes into contact with food during use, and the surface opposite the inner surface is the outer surface of the cookware. During the micro-arc oxidation process, the outer surface of the cookware substrate also undergoes a certain reaction, thereby improving the non-stick properties of both the inner and outer surfaces of the cookware, preventing dirt from accumulating, and at the same time, enhancing the hardness and wear resistance of the cookware.

[0025] It should be noted that compared with a coating formed by spraying a metal oxide (e.g., titanium dioxide) directly on the surface of the cookware base, the surface layer with an amorphous oxide layer formed by metal oxide obtained in the present application can greatly improve the non-stick performance of the cookware due to the amorphous oxide layer on the surface.

[0026] According to the present application, different oxidation depths will cause the cookware to present different colors. Therefore, the present application can not only obtain the expected color of the inner surface of the cookware due to the thickness of the oxidation, but also improve the non-stickiness of the cookware by forming an amorphous oxide layer, thereby making the cookware more competitive.

[0027] Figure 1The non-stick coating is formed by a binary titanium-iron amorphous alloy. After micro-arc oxidation treatment, most or all of the metal on the surface of the non-stick coating can be oxidized into corresponding metal oxides, thereby forming an oxide layer with an amorphous structure on the outer layer of the non-stick coating through the metal oxides. Figure 1 As shown, the characteristic peaks are not particularly obvious, the miscellaneous peaks are numerous and chaotic, the crystallinity is poor, the oxide layer has obvious amorphous bulges, and the oxide layer shows an amorphous trend. According to the conventional full spectrum fitting method, the amorphous phase content is calculated to be 92%.

[0028] In the prior art, coatings formed by metal elements or ordinary alloys generally do not have amorphous properties or have a low amorphous content. Therefore, in some embodiments of the present application, the amorphous content of the oxide layer formed by a mixture of metal silicon powder and at least one of metal elements and ordinary alloys is not less than 65%. Amorphous alloy materials may have different amorphous properties depending on the material, but the amorphous phase usually reaches a limit easily, and the amorphous content is difficult to increase. In some embodiments of the present application, the amorphous content of the oxide layer formed by a mixture of amorphous alloy and metal silicon powder can be increased by at least 4%. It can be seen that the non-stick coating after oxidation treatment according to the present application can make the non-stick coating without amorphous phase have amorphous properties, and can also make the amorphous content of the non-stick coating with amorphous properties further increased.

[0029] Provide pot base

[0030] According to the present application, the cookware substrate can be made from a conventional substrate for making cookware. In an embodiment, the method for making the cookware includes the step of providing the cookware substrate. Specifically, the step of providing the cookware substrate includes preparing the substrate, stretching the substrate into the shape of the cookware, and performing alkaline cleaning, degreasing, and drying operations on the surface of the cookware to prevent affecting the bonding strength between the subsequent coating and the cookware substrate.

[0031] In some embodiments, the cookware substrate may include a stainless steel substrate, a titanium substrate, or a composite substrate having these substrates as inner and outer surfaces. The composite substrate may include, for example, a titanium-aluminum-stainless steel three-layer composite substrate. The materials forming the inner and outer surfaces of these substrates all have a certain degree of corrosion resistance and are therefore not susceptible to corrosion.

[0032] To reduce the weight of the cookware, in other embodiments, the cookware base comprises one of an aluminum base, a magnesium base, an iron base, and a composite base formed from at least two of the metals aluminum, magnesium, and iron. In exemplary embodiments, the composite base includes, for example, an iron-aluminum-iron three-layer composite base or an iron-aluminum two-layer composite base. Because the materials forming these bases are lighter than stainless steel or titanium, they can significantly reduce the weight of the cookware.

[0033] Because aluminum, magnesium, or iron are easily oxidized materials, corrosion is likely to occur when the cookware substrate is formed from such materials, limiting the materials that can be used to manufacture the cookware. Therefore, according to some embodiments of the present application, the method for manufacturing the cookware further includes, before forming the non-stick coating, forming a transition layer on the surface of the cookware substrate using a corrosion-resistant material, and forming a non-stick coating on the surface of the transition layer. According to the present application, the method for manufacturing the cookware can be adapted to a wider variety of substrates, thereby expanding the range of substrates that can be used for cookware manufacturing and providing greater versatility. According to the present application, the corrosion-resistant material is a ceramic material, specifically a ceramic material with a spherical appearance. The coating formed by plasma spraying ceramic materials with spherical particles has a higher density than coatings formed from metal materials, preventing corrosive media from penetrating the cookware substrate and causing corrosion. Furthermore, due to the inherent corrosion resistance of the ceramic material, the surface is largely corrosion-resistant, making the ceramic material suitable for inhibiting rust on the cookware substrate. In this application, spherical refers to a ceramic material having a smooth surface with an arc-shaped transition, specifically, a spherical or elliptical shape. Of course, this application does not necessarily limit it to a spherical structure.

[0034] In an embodiment, the ceramic material may include at least one of aluminum oxide, titanium oxide, zirconium oxide, and titanium suboxide. The above materials are low in cost, easy to purchase, and have good corrosion resistance.

[0035] In an embodiment, the particle size of the corrosion-resistant material may be 10-50 μm. If the particle size of the corrosion-resistant material is greater than 50 μm, the pores of the formed transition layer may be too large due to the excessively large material particles, thereby weakening the corrosion resistance. In addition, the excessively large particles may cause a high probability of rebounding after impacting the substrate surface, thereby reducing the deposition efficiency of the material and wasting raw materials. If the particle size of the corrosion-resistant material is less than 10 μm, the particles may be too small, resulting in construction difficulties during the plasma spraying process (for example, uneven powder feeding due to poor powder fluidity; insufficient flight speed due to the powder being too small and too light, reducing deposition efficiency and wasting raw materials).

[0036] In an embodiment, the thickness of the transition layer can be 30-100 μm, which can provide good corrosion resistance without affecting the bonding strength between the non-stick coating and the cookware base. If the thickness of the transition layer is greater than 100 μm, the overall stress of the cookware coating may be excessive due to the excessive thickness, which in turn may affect the bonding strength between the non-stick coating and the cookware base, causing the non-stick coating to crack and fall off, or crack and fall off due to mechanical shock and thermal shock during use. If the thickness of the transition layer is less than 30 μm, the cookware base may not be fully covered due to the excessive thickness, leaving gap defects and affecting the ultimate corrosion resistance.

[0037] Prepare metal materials

[0038] According to the present application, the metal material includes a metal or an alloy. The metal includes at least one of Mg, Al, Ti, Zr, Nb, and Ta, which itself has a crystalline structure. The alloy includes a common alloy or an amorphous alloy. The common alloy may be an alloy formed by at least two metals of Mg, Al, Ti, Zr, Nb, and Ta, which itself has a crystalline structure. The amorphous alloy includes at least one of a binary amorphous alloy, a ternary amorphous alloy, and a high-entropy amorphous alloy, which has an amorphous structure.

[0039] According to the present application, Mg, Al, Ti, Zr, Nb, and Ta are easily oxidized, and the resulting metal oxides have a darker color and are stable and resistant to change, thus ensuring that the color of the cookware does not change with use. The amorphous alloy formed by at least one active metal among Mg, Al, Ti, Zr, Nb, or Ta can, through micro-arc oxidation, transform the crystalline structure of the surface of the non-stick coating formed by spraying into an amorphous phase again. This can improve the non-stick performance of the cookware due to the increased proportion of amorphous materials.

[0040] In some embodiments, the binary amorphous alloy includes two main metal elements with a total atomic percentage of more than 90% and a balance of secondary non-metal elements, with the atomic percentage of the total atomic percentage being 100%, and the atomic percentage of any one of the two main metal elements is more than 10%. In an exemplary embodiment, the two main metal elements include two of Mg, Al, Ti, Zr, Nb, and Ta, and the secondary metal element includes at least one of C, N, O, B, S, and P. Exemplarily, the binary alloy includes: Mg 20 Al 70 P2C4N4、Ti 60 Ta 35 C1N1O2P1、Al 80 Zr 10 C2B2S4P2、Nb 40 Ta 50 C2N1O2B2S2P1.

[0041] In these embodiments, the main metal elements of the binary amorphous alloy are relatively active, and multi-metal oxides are generated during the micro-arc oxidation process, which expands in volume. The entry of a large number of oxygen atoms causes a significant change in the interaction force between metal atoms, increases the degree of lattice distortion, and increases the degree of amorphization.

[0042] In other embodiments, the amorphous alloy includes two main metal elements with a total atomic percentage of more than 90% and a balance of secondary non-metal elements, with the total atomic percentage being 100%, and the atomic percentage of any one of the two main metal elements is more than 10%. In an exemplary embodiment, the two main metal elements include one of Mg, Al, Ti, Zr, Nb and Ta (relatively active metals), and the two main metal elements also include one of V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Y, Mo, Tc, In, Sn, Sb, Hf and W (relatively inactive metals). The secondary non-metal elements include at least one of C, N, O, B, S and P. Exemplarily, the binary amorphous alloy includes: Mg 20 Fe 70 P2C4N4、Ti 70 Co 25 C1N1O2P1、Ta 80 Hf 15 C1B2S1P1、Nb 30 Sb 60 C1N2O2B2S2P1.

[0043] In these embodiments, the main metal elements of the binary amorphous alloy are relatively active, so during the oxidation process, oxygen atoms react with some of the relatively active metal atoms and precipitate in the form of metal oxides. The relatively active metal atoms migrate away, generating defects such as holes, which causes changes in the interaction forces between the remaining metal atoms, increases the degree of lattice distortion, and increases the degree of amorphization.

[0044] According to the present application, the greater the difference in atomic radius between the main metal elements in a binary alloy, the more likely lattice distortion will occur, resulting in a higher degree of amorphization and lower surface energy in the resulting alloy material. In an exemplary embodiment, the electronegativity difference between the main metal elements in the binary alloy is greater than 0.2. Furthermore, four or more impurity elements can be selected in the same binary amorphous alloy. The more impurity elements there are, the more chaotic the lattice becomes, and the more likely it is to form an amorphous structure.

[0045] According to the present application, the shape of the metal material can be specifically configured according to actual needs. For example, the metal material can be spherical or irregular in shape. Compared to spherical metal materials, irregularly shaped metal materials are relatively cheaper, typically costing only one-tenth of the cost of spherical metal materials. Therefore, to save costs, the metal material according to the present application can be an irregularly shaped metal material.

[0046] In the embodiment, the particle size of the metal material is 200-500 mesh. If the particle size of the metal material is larger than 200 mesh, the powder feeding pipe may be blocked due to the large particles, and the large particles may lead to insufficient melting of the particles, and there is a high probability of rebound after hitting the surface of the substrate, thereby reducing the deposition efficiency and wasting raw materials; if the particle size of the metal material is less than 500 mesh, the particles may be too small, resulting in construction difficulties in thermal spraying processes such as plasma spraying (for example, uneven powder feeding due to poor powder fluidity; insufficient flight speed due to the powder being too small and too light, reducing deposition efficiency, wasting raw materials, and easily causing powder over-melting and oxidation to ash).

[0047] Forms a non-stick coating

[0048] According to the present application, the non-stick coating of the present application can be formed on the cookware substrate using existing layer-forming processes, for example, thermal spraying can be used. Thermal spraying can form a non-stick coating with a certain surface roughness, and thermal spraying can improve the bonding strength between the coating and the cookware substrate, thereby extending the service life of the cookware.

[0049] In an embodiment, the step of forming the non-stick coating comprising a metal material on the cookware substrate comprises spraying at least one of a metal element and an alloy on the cookware substrate to form the non-stick coating comprising the metal material.

[0050] In the embodiment, the non-stick coating is a thermal spray coating with a rough structure formed by plasma spraying. According to the present application, the thermal spray coating can be pre-made to have a certain degree of amorphousness, so that the amorphous content of the cookware coating can be further increased through micro-arc oxidation. Of course, the present application does not impose too many restrictions on this. Even if the thermal spray coating does not have non-stick properties, the oxide layer formed by micro-arc oxidation can also have an amorphous structure due to lattice distortion.

[0051] In an embodiment, the thermal spray coating has a certain degree of amorphousness. Specifically, the plasma spraying method includes the following steps.

[0052] Step S101: placing the side of the cookware opposite to the sprayed surface (ie, the outer surface of the cookware) in a circulating cooling air environment, wherein the temperature of the cooling air is between -20°C and -10°C.

[0053] In step S102, 200-500 mesh metal powder is loaded into the powder feeder, and the plasma spraying process parameters are set. The specific parameters for the plasma spraying process are: arc current: 300-600A; voltage: 40-75V; main gas (argon) flow rate: 1000-2000L / h; hydrogen flow rate: 40-150L / h; powder feed gas flow rate: 300-600L / h; powder feed rate: 30-80g / min; spraying distance (nozzle to workpiece): 10-15cm; spraying angle: 45-80°. Under these parameters, the high-pressure plasma flame formed at the nozzle heats the surface of the metal material until it is slightly melted. The metal material then rapidly cools at a cooling rate of 20-80K / s and is deposited on the inner surface of the cookware, forming a non-stick coating with a rough texture.

[0054] In some embodiments, the cookware is placed in a low-temperature environment and a non-stick coating is formed by plasma spraying a common alloy or metal, wherein the non-stick coating comprises a certain amorphous content of the metal or common alloy. The amorphous alloy material undergoes a micro-melting process on the surface while remaining unchanged on the inside. Thus, when sprayed onto a substrate, the coating forms core particles having an amorphous structure and outer cladding particles having a crystalline structure located on the surface of the core particles. The crystalline structure of the outer cladding particles can be transformed into an amorphous structure after micro-arc oxidation treatment.

[0055] In other embodiments, the non-stick coating formed by plasma spraying of ordinary alloys or metals is a non-stick coating having a crystalline structure formed by metals or ordinary alloys. The surface of the amorphous alloy material will be slightly melted by plasma spraying while the interior remains unchanged, so when sprayed on the substrate, it will form core particles with an amorphous structure and outer coating particles with a crystalline structure located on the surface of the core particles. The crystal structure of the outer coating particles can be transformed into an amorphous structure after micro-arc oxidation treatment. It should be noted that when the cookware is placed in a low-temperature environment, since the particles are rapidly cooled and deposited on the surface of the cookware substrate at a relatively high temperature, the particles do not have time to form a complete crystalline structure, and thus tend to form a non-stick coating with a relatively large proportion of amorphous particles.

[0056] In the embodiment, the thickness of the non-stick coating is 40-100 μm. If the thickness of the non-stick coating is greater than 100 μm, the overall thermal spray coating may be subjected to excessive stress due to the excessive thickness, thereby affecting the bonding strength between the non-stick coating and the cookware substrate, and may crack and fall off, or crack and fall off due to mechanical shock and thermal shock during use. It may also lead to excessive surface roughness, making subsequent processing difficult and costly. If the thickness of the non-stick coating is less than 40 μm, it may be too thin to completely cover the underlying layer, or the non-stick layer may be partially exposed during the subsequent sanding and oxidation process, exposing the underlying layer, affecting the non-stick effect.

[0057] Micro-arc oxidation treatment of non-stick coatings

[0058] In an embodiment, the micro-arc oxidation step includes preparing an electrolyte including a silicate.

[0059] According to the present application, the electrolyte can be an electrolyte of a silicate system. The electrolyte of the silicate system includes NaOH and Na2SiO3, wherein 2-6g of NaOH and 4-10g of Na2SiO3 are contained in 1L of electrolyte. Na2SiO3 can generate amorphous silicon dioxide during the micro-arc oxidation process. The amorphous silicon dioxide can penetrate into the metal oxide and serve as part of the amorphous oxide layer, thereby enhancing the non-stick effect. Sodium hydroxide is a strong base with strong ionization ability, so it can increase the conductivity of the electrolyte, making the transmission rate of electrons in the redox reaction faster, so that the expected oxide layer can be obtained in a shorter time.

[0060] According to the present application, the electrolyte can also be a mixed system electrolyte mainly composed of silicates. In an exemplary embodiment, the mixed system electrolyte includes at least one of phosphates and aluminates in addition to more than 60% of silicates. In these embodiments, at least one of phosphates and aluminates is added to the mixed system electrolyte. The phosphate can accelerate the initial film formation speed and facilitate the formation of the oxide layer. The addition of aluminates can generate aluminum oxide during the film formation process, thereby increasing the hardness and wear resistance of the oxide layer. According to the present application, the electrolyte can be set according to actual needs, and the present application does not impose too many restrictions on this.

[0061] According to the present application, after the electrolyte is prepared, the cookware substrate with a non-stick coating is placed in the electrolyte at a preset temperature and maintained for a preset time, so that the silicate in the electrolyte generates an amorphous silicon dioxide film, and the amorphous silicon dioxide film penetrates into the metal oxide and together serves as an amorphous oxide layer.

[0062] According to the present application, the micro-arc oxidation equipment also includes a cooling device, which controls the temperature of the electrolyte. In an exemplary embodiment, the temperature of the electrolyte is set to 0-20°C. Under the influence of low temperature, silicate will generate amorphous silicon dioxide during the film formation process. The generated amorphous silicon dioxide will penetrate into the metal oxide and form an amorphous oxide layer on the surface of the non-stick coating. Due to the rapid cooling rate during the film formation process (the temperature difference between the electrolyte and the discharge area during the micro-arc oxidation process is large, resulting in a faster cooling rate), an amorphous oxide layer with a higher degree of amorphism can be obtained. In addition, the micro-arc oxidation equipment also includes a cathode material made of stainless steel.

[0063] According to the present application, plasma spraying does not completely melt the metal material. Taking amorphous alloy materials as an example, under the influence of the plasma flame, the surface of the amorphous alloy material will slightly melt while the interior remains unchanged. It then impacts the surface of the cookware substrate to form a non-stick coating. The slightly melted metal on the surface of the amorphous alloy will then recrystallize and precipitate crystals under the influence of low temperatures, causing the surface of the resulting thermal spray coating to transform into a crystalline structure. However, because the thermal spray coating appears as irregular particles and has a layered structure, the surface not only has a concave-convex structure but also contains defects such as pores. Therefore, the surface of the thermal spray coating can be sanded to remove such defects. Furthermore, the sanding process can partially remove the crystals in the raised portions of the concave-convex structure, thereby increasing the proportion of the amorphous phase in the non-stick coating. It should be noted that at this point, the surface layer of the thermal spray coating is still mostly crystalline, for example, in the surface depressions and pores. These areas are inaccessible to sanding, so even sanding cannot completely remove them. To this end, according to the present application, a cookware substrate having a non-stick coating is subjected to micro-arc oxidation treatment. Oxidation is performed in a low-temperature environment of micro-arc oxidation for a preset time, allowing oxygen atoms to penetrate into the lattice of the crystal structure of the surface layer. The oxygen atoms react with a portion of the active metal to form a metal oxide (having a MO ionic bond, where M represents a metal element). Due to the presence of the metal oxide (MO ionic bond), the equilibrium state of the original metal bond is destroyed, resulting in the appearance of defects such as holes, causing lattice distortion, and increasing the degree of amorphization of the obtained coating. As a result, an amorphous oxide layer with a preset depth is formed on the surface of the non-stick coating, thereby enabling the cookware having the coating to obtain better non-stick properties due to a larger amorphous ratio and lower surface energy. In addition, the silicate in the electrolyte will also form an amorphous silicon dioxide film during the micro-arc oxidation process, which penetrates (confirms) the metal oxide to form an amorphous oxide layer of a preset thickness, wherein the amorphous silicon dioxide film and the metal oxide are staggered. It should be noted that when a metal element or a common alloy is used, the crystal structure of the surface layer of the non-stick coating is transformed into an amorphous structure, forming a surface layer of the non-stick coating having an amorphous oxide layer, thereby being able to have excellent non-stick properties due to the amorphous oxide layer.

[0064] In these embodiments, a silicon dioxide film can be deposited into the micro-arc oxidation film to form a non-stick coating having an oxide layer, which can make the non-stick coating of the cookware denser and reduce the pores, thereby improving the corrosion resistance. The amorphous oxide layer has an alternating distribution of amorphous silicon dioxide films and amorphous metal oxides, thus having excellent non-stick properties. In addition, when the alloy is an amorphous alloy, at least a portion of the crystal structure of the thermal spray coating can be transformed into an amorphous structure after micro-arc oxidation treatment. Thus, the use of amorphous alloy materials and micro-arc oxidation treatment can achieve better non-stick properties.

[0065] According to a second aspect of the present application, a cookware is provided, wherein the cookware is manufactured using the method for manufacturing cookware provided in each of the above embodiments.

[0066] In an embodiment, the cookware includes a cookware base 100 and a coating 200 located on the surface of the cookware base. Figure 2 and Figure 3 As shown, the coating 200 on the surface of the cookware substrate includes an initial non-stick coating 210 and an oxide layer 220 located on the surface of the initial non-stick coating 210. The oxide layer 220 is generated from the outside to the inside and has a preset thickness on the surface of the non-stick coating 210. It also has an amorphous phase, so that the non-stick coating is divided into the initial non-stick coating 210 and the oxide layer 220 located on the surface of the initial non-stick coating 210.

[0067] According to the present application, the surface layer of the cookware coating includes an amorphous oxide layer of a preset thickness. The amorphous oxide layer is formed by metal oxide, and the metal oxide is formed by micro-arc oxidation of a metal material.

[0068] According to the present application, the amorphous oxide layer is formed by instantaneous condensation of a metal oxide of one of Mg, Al, Ti, Zr, Nb and Ta, which distorts the original structure. It has excellent non-stickiness, high density and hardness, and good corrosion resistance.

[0069] In some embodiments, the metal material is a single metal or an alloy, and the amorphous oxide layer is a mixed layer formed by alternating amorphous silicon dioxide film layers and amorphous metal oxide layers, wherein the amorphous silicon dioxide film layers are formed by oxidation of silicates in an electrolyte. Specifically, the degree of amorphization of the amorphous silicon dioxide film layers decreases from the outside to the inside.

[0070] In an embodiment, the thickness of the amorphous oxide layer is 10-50 μm. If the thickness of the amorphous oxide layer is greater than 50 μm, the oxidation time may be too long due to the thickness being too thick, resulting in an increase in film defects (for example, reduced film bonding strength), excessive roughness, and the degree of amorphization of the oxide film closer to the inner layer is lower, which has little effect on improving the non-stick property. If the thickness of the amorphous oxide layer is less than 10 μm, it may be too thin and easily disappear due to wear during later use, affecting the durability of the effect.

[0071] The metal materials used in non-coating non-stick technology are mostly light-colored, and the coatings formed are also mostly light-colored. However, according to the present application, the oxide film has a preset color, which is different from the color formed by conventional metal materials and is mostly dark-colored (such as titanium dioxide is dark and ferroferric oxide is black). This can improve the anti-fouling effect due to the darker color and strong stain resistance. In addition, the oxide layer has a certain hardness and a preset thickness, so it can be shovel-resistant and durable. Since the surface of the oxide layer is a rough surface formed by plasma spraying, the depressions of the oxide film with a rough structure can last and not be damaged. In addition, during the micro-arc oxidation process, the protruding defects on the surface will be partially dissolved, which has a certain polishing effect, making it smoother and more fluent when using the metal spatula, thereby improving the user experience of the cookware.

[0072] In an embodiment, the cookware substrate includes one of an aluminum substrate, an iron substrate, a magnesium substrate, a stainless steel substrate, a titanium substrate, and a composite substrate formed by the above substrates.

[0073] The present application will be described in detail below with reference to the embodiments, but the protection scope of the present application is not limited to the embodiments.

[0074] Example 1

[0075] The metal material according to Example 1 was prepared by the following method.

[0076] Step S10: providing a stainless steel cookware base with a thickness of 1.8 mm.

[0077] Step S20: providing titanium powder with a particle size of 400 mesh as a metal material.

[0078] Step S30: preparing a non-stick coating.

[0079] Step S31 , placing the outer surface of the cookware in a circulating cooling air environment, with the temperature of the cooling air set at -10°C.

[0080] In step S32, the metal material is placed in the powder feeder of the plasma spraying equipment. The parameters of the plasma spraying equipment are set as follows: arc current: 550A; voltage: 55V; main gas (argon) flow rate: 1800L / h; main gas (argon) pressure: 1.2MPa; hydrogen flow rate: 50L / h; hydrogen pressure: 0.7MPa; powder feeding rate: 40g / min; spraying distance (nozzle to workpiece): 11cm; spraying angle: 60°. Under these parameters, the high-pressure plasma flame formed at the muzzle heats the surface of the metal material until it melts, and then deposits it on the surface of the cookware substrate, forming a non-stick coating with a thickness of 60μm on the cookware substrate.

[0081] In step S40 , an oxide layer having a predetermined thickness and an amorphous phase is formed on the surface of the non-stick coating.

[0082] The resulting cookware with a non-stick coating was subjected to micro-arc oxidation. Specifically, a silicate electrolyte was prepared. The silicate electrolyte included NaOH and Na2SiO3, with a mass concentration of 5g / L of Na2SiO3 and a mass concentration of 3g / L of NaOH. The cookware substrate with the non-stick coating was then placed in the electrolyte at 20°C, with a stainless steel cathode. The oxidation voltage was 500V, the pulse width was 500μs, and the pulse interval was 1500s, and the oxidation was maintained for 25 minutes, resulting in a cookware with an amorphous oxide layer with a thickness of 15μm.

[0083] Example 2

[0084] The cookware of Example 2 was prepared by the same method as that of Example 1, except that the titanium powder as the metal material was replaced with titanium-zirconium alloy powder.

[0085] Example 3

[0086] In addition to replacing titanium powder as a metal material with amorphous alloy Mg 20 Al 70 Except for P2C4N4, the cookware of Example 3 was prepared by the same method as that of Example 1.

[0087] Example 4

[0088] In addition to replacing the titanium powder as the metal material with amorphous alloy Nb 40 Ta 50 Except for C2N1O2B2S2P1, the cookware of Example 4 was prepared by the same method as that of Example 1.

[0089] Example 5

[0090] In addition to replacing the titanium powder as the metal material with amorphous alloy Nb 30 Sb 60 Except for C1N2O2B2S2P1, the cookware of Example 5 was prepared by the same method as that of Example 1.

[0091] Example 6

[0092] The cookware of Example 6 was prepared using the same method as that of Example 1, except that the stainless steel substrate was replaced by a titanium substrate.

[0093] Example 7

[0094] The cookware of Example 7 was prepared by the same method as that of Example 1, except that the stainless steel substrate was replaced by an aluminum substrate and a transition layer with a thickness of 50 μm was formed on the aluminum substrate.

[0095] Example 8

[0096] The cookware of Example 8 was prepared by the same method as that of Example 1, except that the stainless steel substrate was replaced by an iron-magnesium composite substrate and a transition layer with a thickness of 50 μm was formed on the iron-magnesium composite substrate.

[0097] Comparative Example 1

[0098] Titanium powder was plasma sprayed on a stainless steel substrate to form a coating with a thickness of 60 μm (the plasma spraying parameters were the same as those in Example 1), thereby forming the cookware of Comparative Example 1.

[0099] Comparative Example 2

[0100] The cookware of Comparative Example 2 was formed by plasma spraying titanium-zirconium alloy powder on a stainless steel substrate to form a coating with a thickness of 60 μm (the plasma spraying parameters were the same as those in Example 1).

[0101] Comparative Example 3

[0102] Using amorphous alloy Mg 20 Al 70 P2C4N4 was plasma sprayed on the stainless steel substrate to form a coating with a thickness of 60 μm (the plasma spraying parameters were the same as those in Example 1), thereby forming the cookware of Comparative Example 3.

[0103] Comparative Example 4

[0104] Using amorphous alloy Nb 40 Ta 50 C2N1O2B2S2P1 is plasma sprayed on a stainless steel substrate to form a coating with a thickness of 60 μm (the plasma spraying parameters are the same as those in Example 1), thereby forming the cookware of Comparative Example 4.

[0105] Comparative Example 5

[0106] Using amorphous alloy Nb 30 Sb 60 C1N2O2B2S2P1 was plasma sprayed on a stainless steel substrate to form a coating with a thickness of 60 μm (the plasma spraying parameters were the same as those in Example 1), thereby forming the cookware of Comparative Example 5.

[0107] Comparative Example 6

[0108] The cookware of Comparative Example 6 was formed by plasma spraying metallic silicon powder on a stainless steel substrate to form a coating with a thickness of 60 μm (the plasma spraying parameters were the same as those in Example 1).

[0109] Comparative Example 7

[0110] The cookware of Comparative Example 7 was prepared using the same method as Example 1, except that the stainless steel substrate was replaced by an aluminum substrate.

[0111] Table 1 Parameters of the Examples and Comparative Examples of the present application

[0112] serial number Metal materials matrix Micro-arc oxidation transition layer Example 1 titanium powder Stainless steel substrate have none Example 2 Titanium-zirconium alloy powder Stainless steel substrate have none Example 3 <![CDATA[Mg 20 To the 70 P2C4N4]]> Stainless steel substrate have none Example 4 <![CDATA[Nb 40 He / She 50 C2N1O2B2S2P1]]> Stainless steel substrate have none Example 5 <![CDATA[Nb 30 Sb 60 C1N2O2B2S2P1]]> Stainless steel substrate have none Example 6 titanium powder Titanium matrix have none Example 7 titanium powder Aluminum base have have Example 8 titanium powder Iron-magnesium composite matrix have have Comparative Example 1 titanium powder Stainless steel substrate none none Comparative Example 2 Titanium-zirconium alloy powder Stainless steel substrate none none Comparative Example 3 <![CDATA[Mg 20 To the 70 P2C4N4]]> Stainless steel substrate none none Comparative Example 4 <![CDATA[Nb 40 He / She 50 C2N1O2B2S2P1]]> Stainless steel substrate none none Comparative Example 5 <![CDATA[Nb 30 Sb 60 C1N2O2B2S2P1]]> Stainless steel substrate none none Comparative Example 6 Metal silicon powder Stainless steel substrate none none Comparative Example 7 titanium powder Aluminum base have none

[0113] Performance index test

[0114] (1) The amorphization degree of the coating of the cookware of Examples 1-8 and Comparative Examples 1-7 was tested, and the test method was as follows:

[0115] Amorphous Degree Test Method: XRD testing is performed and analyzed using a conventional full-spectrum fitting method to determine the degree of amorphization of the sample. The conventional full-spectrum fitting method follows these steps: First, a crystalline phase with the same chemical structure as the amorphous phase is found. The amorphous phase is assumed to be a small grain of this crystalline phase, which can be used to establish a model for the peak position and intensity of the amorphous phase. Second, the spectrum of the pure amorphous phase is fitted to determine the grain size and microstrain. Finally, the grain size and microstrain are fixed, and this phase is included in the conventional Rietveld quantitative calculation to obtain the amorphous content (i.e., the degree of amorphization) and record it in Table 2 below.

[0116] Table 2 Amorphization degree test data of the examples and comparative examples of the present application

[0117]

[0118] (2) The cookware of Examples 1-8 and Comparative Examples 1-7 were subjected to performance tests and recorded in Table 3 below. The specific performance test methods are as follows:

[0119] ① Initial non-stickiness test method: GB / T32095.2-2015 fried egg non-stickiness test method. This method is an initial non-stickiness test and is divided into levels I, II, and III. Level I has the best non-stickiness and level III has the worst non-stickiness.

[0120] ② Long-lasting non-stick test method: The long-lasting non-stick test method in GB / T32388-2015 is measured in times. The higher the number, the longer the life. The non-stick result is evaluated every 500 times, and the number of times is recorded until it reaches Level III.

[0121] ③ Evaluation of the non-stick properties of dishes, which can show the stain resistance and non-stick properties during actual use.

[0122] 1) Stir-fried tofu

[0123] Prepare ingredients: 150g firm tofu (cut into cubes, about 10 pieces) and 20mL cooking oil.

[0124] Step 1. Clean the wok and heat it to 200°C over high heat. Pour in cooking oil and heat until a light smoke appears. Rotate the wok to allow the oil to fully soak the entire inner surface. Add the tofu and reduce the heat to medium. Step 2. Once the tofu is lightly browned on one side, flip it over and continue frying until both sides are golden brown. Remove from heat and serve.

[0125] 2) Stir-fried shredded potatoes

[0126] Prepare ingredients: 200g shredded potatoes, 20mL cooking oil, 25g vinegar and 5g light soy sauce.

[0127] Step 1: Clean the surface of the wok and heat it to 200°C over high heat. Pour in cooking oil and heat until a small amount of smoke is produced. Rotate the wok to fully submerge the entire inner surface of the wok. Add shredded potatoes and stir-fry with a spatula until the potatoes are half cooked. Step 2: Add vinegar and light soy sauce and continue stir-frying until cooked through.

[0128] Evaluation method: Grade A: basically non-stick during normal stir-frying, and the pan is relatively clean; Grade B: slightly sticky during normal stir-frying, with a small amount of residue; Grade C: sticky during normal stir-frying, with a large amount of residue in the pan.

[0129] Table 3 Performance index test data of the examples and comparative examples of the present application

[0130]

[0131] In summary, it can be seen from Tables 1 to 3 above that micro-arc oxidation can form an oxide layer with a large amorphous proportion, thereby enabling the cookware to have excellent non-stick properties.

[0132] According to the cookware manufacturing method of the present application, the surface of the amorphous oxide layer serves as the contact surface of the cookware with the food. The amorphous oxide layer, having a predetermined thickness (depth), has a low surface energy, thereby improving the non-stick properties of the cookware. When the non-stick properties are improved, dirt and grime are less likely to accumulate in the pores or recesses, thereby improving the visual experience of using the cookware. In addition, during use of the cookware, the surface of the amorphous oxide layer serves as the contact surface of the cookware with the food. The metal oxide inside is stable, resistant to discoloration, and has a darker color, thereby enhancing the stain resistance of the cookware surface, further improving the visual experience of using the cookware.

[0133] Although the embodiments of the present application have been described in detail above, those skilled in the art may make various modifications and variations to the embodiments of the present application without departing from the spirit and scope of the present application. However, it should be understood that, in the opinion of those skilled in the art, such modifications and variations will still fall within the spirit and scope of the embodiments of the present application as defined in the claims.

Claims

1. A method for manufacturing a cookware, characterized in that: The method for manufacturing a cookware comprises: Thermal spraying of titanium, titanium-zirconium alloy, amorphous alloy Mg on the base of the cookware 20 Al 70 P2C4N4, amorphous alloy Nb 40 Ta 50 C2N1O2B2S2P1 or amorphous alloy Nb 30 Sb 60 C1N2O2B2S2P1 to form a non-stick coating including metal materials; An electrolyte is provided, wherein the electrolyte includes NaOH and Na2SiO3, the mass concentration of the NaOH being 2g / L-6g / L, and the mass concentration of the Na2SiO3 being 4g / L-10g / L; a cookware substrate having the non-stick coating is placed in the electrolyte, and the temperature of the electrolyte is controlled to be 0°C-20°C, so as to perform a micro-arc oxidation treatment on the cookware substrate having the non-stick coating, so that at least a portion of the metal in the metal material on the surface layer of the non-stick coating is oxidized into metal oxide, and the silicate in the electrolyte generates an amorphous silicon dioxide film, the amorphous silicon dioxide film penetrates into the metal oxide and forms an amorphous oxide layer having a preset thickness on the surface layer of the non-stick coating, and the surface of the amorphous oxide layer serves as the inner surface of the cookware.

2. The method for manufacturing a cookware according to claim 1, wherein: The amorphous silicon dioxide film has a gradually decreasing degree of amorphization from the outside to the inside of the cookware.

3. The method for manufacturing a cookware according to claim 1, wherein: The non-stick coating is a thermal spray coating with a rough surface structure formed by plasma spraying an amorphous alloy. The thermal spray coating includes core particles with an amorphous structure and outer coating particles with a crystalline structure located on the surface of the core particles. The crystalline structure of the outer coating particles can be transformed into an amorphous structure after micro-arc oxidation treatment.

4. The method for manufacturing a cookware according to claim 1, wherein: The cookware substrate includes one of an aluminum substrate, an iron substrate, a magnesium substrate, a stainless steel substrate, a titanium substrate, and a composite substrate formed between the above substrates.

5. The method for manufacturing a cookware according to claim 1, wherein: The method for manufacturing a cookware further comprises: before the step of forming the non-stick coating, forming a transition layer on the surface of the cookware base body using a corrosion-resistant material, and forming the non-stick coating on the surface of the transition layer.

6. The method for manufacturing a cookware according to claim 5, wherein: The corrosion-resistant material is at least one of aluminum oxide, titanium oxide, zirconium oxide and titanium suboxide; and / or the thickness of the transition layer is 30 microns to 100 microns.

7. The method for manufacturing a cookware according to claim 1, wherein: The amorphous oxide layer comprises staggered amorphous silicon dioxide films and amorphous metal oxides; and / or the amorphous oxide layer has a thickness of 10 micrometers to 50 micrometers.

8. The method for manufacturing a cookware according to claim 1, wherein: The thickness of the non-stick coating is 40 microns to 100 microns, and / or the titanium, titanium-zirconium alloy, amorphous alloy Mg 20 Al 70 P2C4N4, amorphous alloy Nb 40 Ta 50 C2N1O2B2S2P1 or amorphous alloy Nb 30 Sb 60 The particle size of C1N2O2B2S2P1 is 200 mesh-500 mesh.

9. The method for manufacturing a cookware according to claim 1, wherein: The color of the metal oxide is darker than the color of the metal.

10. A cookware, characterized in that: The cookware is manufactured by the method for manufacturing a cookware according to any one of claims 1 to 9.

Images