A wear-resistant and low-adhesion cookware and its manufacturing method

Abstract

This invention provides a wear-resistant and low-adhesion cookware and its manufacturing method. The cookware includes a cookware substrate, on which at least its inner surface is formed a composite functional coating. The composite functional coating, from the side closest to the cookware substrate to the side furthest away from the cookware substrate, sequentially includes: a surface support layer, a metal transition layer, a gradient bonding layer, and a modified DLC functional layer. The cookware of this invention can significantly improve the adhesion and anti-peeling performance of the coating under hot and cold cyclic cooking conditions, while also exhibiting excellent scratch resistance and low adhesion (non-stick) properties, thus improving the product's cost-effectiveness and overall reliability.

Description

Technical Field

[0001] This invention relates to the field of kitchenware technology, and more specifically to a wear-resistant and low-adhesion cookware and a method for manufacturing the same. Background Technology

[0002] Currently, most non-stick pans on the market use fluorinated organic non-stick coatings such as PTFE and PFA. These coatings initially offer good non-stick performance, but their low hardness makes them susceptible to wear and tear from friction with spatulas, hard food, and cleaning tools over long-term use, leading to a decline in non-stick performance and a shorter lifespan for the pans. Some pans also use ceramic non-stick coatings or plasma-sprayed ceramic wear-resistant layers. These coatings have higher hardness than organic non-stick layers, but their higher surface energy results in faster degradation of non-stick performance over time. Furthermore, they are prone to micro-cracks, chipping, or localized peeling under thermal shock and high-temperature dry-heating conditions.

[0003] In recent years, some technologies have attempted to use physical vapor deposition (PVD) to form hard coatings on cookware surfaces. However, coatings deposited using ordinary PVD methods have the following problems: First, there is a large difference in hardness between the coating and the cookware substrate (especially stainless steel, aluminum alloy, etc.), resulting in insufficient adhesion and easy peeling during alternating hot and cold cooking. Second, the surface energy of ordinary PVD coatings is still relatively high, which is insufficient for low adhesion (non-stick) to oils and food, making it difficult to meet the initial requirements for "non-stick" cookware in cooking. Third, the shadowing effect exists on the inner wall of deep pots (such as woks) during the PVD process, resulting in uneven film thickness on the bottom, side walls, and rim of the pot, affecting the overall performance consistency. Fourth, micropores and microdefects that may exist on the surface of a single PVD coating can accelerate the intrusion of oil and salt, causing coating failure. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide a wear-resistant and low-adhesion cookware and its manufacturing method. The cookware of this invention can significantly improve the adhesion and anti-peeling performance of the coating under hot and cold cyclic cooking conditions, while having excellent scratch resistance and low adhesion (non-stick) performance, thereby improving the product's cost-effectiveness and overall reliability.

[0005] To achieve the above objectives, one aspect of the present invention provides a wear-resistant and low-adhesion cookware, comprising: The cookware substrate has a composite functional coating formed on at least its inner surface. The composite functional coating includes, from the side closest to the cookware substrate to the side furthest from the cookware substrate, a surface support layer, a metal transition layer, a gradient bonding layer, and a modified DLC functional layer.

[0006] According to one embodiment of the present invention, the composite functional coating further includes a transparent low surface energy sealing layer, which is disposed on the modified DLC functional layer.

[0007] According to one embodiment of the present invention, the modified DLC functional layer has a differential thickness in different regions of the inner surface of the cookware.

[0008] According to one embodiment of the present invention, the thickness of the modified DLC functional layer is 1.2-2.5 μm in the central region of the bottom of the pot, 0.8-2 μm in the transition region of the bottom of the pot, 0.5-1.2 μm in the sidewall region, and 0.3-1 μm in the rim region of the pot.

[0009] According to one embodiment of the present invention, the transparent low surface energy sealing layer includes one or more of SiOxCy, SiCN, SiOxNy, siloxane sol-gel layer, methylsiloxane modified layer, fluorosilane modified layer, fluorine-containing transparent ceramic hybrid layer, or silicon / fluorine-containing organic-inorganic hybrid layer.

[0010] According to one embodiment of the present invention, the thickness of the transparent low surface energy sealing layer is 20 nm-2 μm.

[0011] According to one embodiment of the present invention, the thickness of the transparent low surface energy sealing layer is 80nm-300nm.

[0012] According to one embodiment of the present invention, the modified DLC functional layer includes one or more of silicon-containing DLC, fluorine-containing DLC, silicon / fluorine co-doped DLC, hydrogen-containing DLC, or hydrogen-free DLC.

[0013] According to one embodiment of the present invention, the surface support layer includes one or more of the following: nitrided layer, carburized layer, nitrocarburized layer, hard anodized layer, micro-arc oxidation layer, ion implantation strengthening layer, or ceramicized surface layer.

[0014] According to one embodiment of the present invention, the material of the metal transition layer includes Ti, Cr, W, Mo, Zr, Si, Nb, Ta or an alloy of the above elements.

[0015] According to one embodiment of the present invention, the gradient bonding layer includes one or more of the following: metal carbide layer, metal carbonitride layer, Si-CN gradient layer, Si-CO gradient layer, TiC, CrC, WC, SiC, TiCN, and CrCN.

[0016] According to one embodiment of the present invention, the carbon content in the gradient bonding layer gradually increases from the side closer to the metal transition layer to the side closer to the modified DLC functional layer.

[0017] Another aspect of the present invention provides a method for preparing abrasion-resistant and low-adhesion cookware, comprising the following steps: (a) A surface support layer is formed after pretreatment of the cookware substrate surface; (b) The cookware with the surface support layer is placed in the PVD+PACVD / PECVD composite vacuum coating equipment to remove contaminants from the cookware and activate the surface. Under vacuum conditions, a metal transition layer and a gradient bonding layer are deposited sequentially on the surface support layer. (c) In the same vacuum chamber, while maintaining a vacuum state, a modified DLC functional layer is formed on the gradient bonding layer by plasma-enhanced chemical vapor deposition or plasma-assisted chemical vapor deposition. (d) A transparent low surface energy sealing layer is formed on the modified DLC functional layer.

[0018] According to one embodiment of the present invention, the parameters in step (c) are as follows: the ultimate vacuum of the vacuum chamber is 1×10⁻⁶. -3 -5×10 -2 The working pressure is 0.1-10 Pa, the workpiece bias voltage is -50 to -1000 V, the workpiece temperature is 80-350℃, the rotating frame speed is 1-20 rpm, the plasma power is 0.5-20 kW, the deposition time is 20-240 min, and the DLC film thickness is 0.3-5 μm.

[0019] According to one embodiment of the present invention, the parameters in step (c) are as follows: the ultimate vacuum of the vacuum chamber is 1×10⁻⁶. -3 -1×10 -2 The working pressure is 0.3-3 Pa, the workpiece bias voltage is -100 to -600 V, the workpiece temperature is 120-250℃, the rotating frame speed is 3-10 rpm, the plasma power is 2-10 kW, the deposition time is 45-150 min, and the DLC film thickness is 0.8-2 μm.

[0020] According to one embodiment of the present invention, the process gas used includes a carbon source gas, a silicon source gas, and / or a fluorine source gas; the carbon source gas includes one or more of CH4 and C2H2; the silicon source gas includes TMS or HMDSO, accounting for 2-10% of the total flow rate of the reaction gas; the fluorine source gas includes one or more of CF4, C2F6, CHF3, fluorinated silanes, and perfluoroalkyl silanes, accounting for 0.5-5% of the total flow rate of the reaction gas.

[0021] According to one embodiment of the present invention, step (c) further includes rotating the pot in the vacuum chamber at a speed of 1-20 rpm and using an internal surface directional plasma source, auxiliary electrode or an annular gas distribution structure to improve the uniformity of the film thickness on the inner wall of the pot, so that the uniformity of the film thickness on the inner wall of the pot reaches within ±30%.

[0022] According to one embodiment of the present invention, step (c) further includes rotating the pot in the vacuum chamber at a speed of 3-10 rpm and using an internal surface directional plasma source, auxiliary electrode or an annular gas distribution structure to improve the uniformity of the film thickness on the inner wall of the pot, so that the uniformity of the film thickness on the inner wall of the pot reaches within ±15%.

[0023] According to one embodiment of the present invention, in step (d), the transparent low surface energy sealing layer is formed by PECVD or PACVD process, with the following process parameters: workpiece temperature is 120-220℃, working pressure is 0.5-3Pa, bias voltage is -50 to -250V, plasma power is 0.5-5KW, deposition time is 10-30min, and the gas used includes one or more of HMDSO, TMS, TEOS, O2, N2, Ar, CF4 and fluorinated silanes.

[0024] According to one embodiment of the present invention, in step (d), the transparent low surface energy sealing layer is formed by a sol-gel method, including the following steps: (1) Prepare a sol containing silane precursor, alcohol solvent, deionized water and low surface energy modifier; (2) The sol is coated onto the surface of the modified DLC functional layer by an automatic atomization spraying method; (3) Curing at 180-260℃ for 20-40 min yields a sealing layer with a thickness of 80-800 nm; Preferably, the silane precursor is methyltrimethoxysilane or tetraethyl orthosilicate, and the low surface energy modifier is perfluoroalkylsilane or methylsiloxane resin.

[0025] According to one embodiment of the present invention, the method further includes the following steps prior to the step of forming a transparent low surface energy sealing layer on the modified DLC functional layer: The modified DLC functional layer was activated by low-power O2 or Ar plasma for 1-10 min at 60-180℃.

[0026] The present invention has the following beneficial technical effects: 1. By setting up a multi-layer transition structure of "surface support layer + metal transition layer + gradient bonding layer", the sudden change in hardness and thermal expansion difference between DLC hard coating and metal soft substrate are effectively alleviated, and the coating's adhesion and anti-peeling performance under hot and cold cycling cooking conditions are greatly improved.

[0027] 2. Modified DLC functional layers (Si-DLC, F-DLC or Si / F-DLC) maintain high hardness (800-3000HV) and high wear resistance, while reducing internal stress through silicon doping and reducing surface energy (surface energy can be lower than 40 mN / m) through fluorine doping, so that cookware has both excellent scratch resistance and low adhesion (non-stick) properties.

[0028] 3. The transparent low surface energy sealing layer can seal the micropores and defects on the surface of the DLC layer, further improving the initial non-stickiness (water contact angle can reach more than 100°), and blocking the intrusion of oil and salt, delaying performance degradation, while maintaining a transparent and beautiful appearance.

[0029] 4. To address the differences in wear and heat load in different areas of the wok (bottom, side walls, and rim), a differentiated DLC thickness was designed, balancing the high wear resistance requirements of the bottom and the low stress requirements of the side walls, thus improving the product's cost-effectiveness and overall reliability.

[0030] 5. The use of PVD+PACVD / PECVD composite equipment to continuously deposit metal transition layers, gradient bonding layers and DLC layers in the same vacuum chamber reduces interface contamination and improves interlayer bonding. Furthermore, through optimization methods such as rotating the rotating frame and using an internal surface directional plasma source, the film thickness uniformity of the deep pot-shaped inner wall is significantly improved (controllable within ±15%). Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other embodiments can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a schematic diagram of a wear-resistant and low-adhesion cookware coating according to an embodiment of the present invention; Figure 2 This is a schematic flowchart of a method for preparing wear-resistant and low-adhesion cookware according to an embodiment of the present invention. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to specific examples and the accompanying drawings.

[0034] Based on the above objectives, a first aspect of the embodiments of the present invention provides an embodiment of a wear-resistant and low-adhesion cookware. Figure 1 The diagram shown is of a cookware.

[0035] like Figure 1 As shown, the cookware may include: The cookware substrate has a composite functional coating formed on at least its inner surface. The composite functional coating includes, from the side closest to the cookware substrate to the side furthest from the cookware substrate, a surface support layer, a metal transition layer, a gradient bonding layer, and a modified DLC functional layer.

[0036] The cookware of this invention can significantly improve the adhesion and anti-peeling performance of the coating under hot and cold cyclic cooking conditions, while also exhibiting excellent scratch resistance and low adhesion (non-stick) properties, thus improving the product's cost-effectiveness and overall reliability. The gradual transition of the surface support layer, metal transition layer, gradient bonding layer, and modified DLC can reduce the risk of hard film-soft substrate, thermal expansion mismatch, and hot and cold shock peeling.

[0037] In a preferred embodiment of the present invention, such as Figure 1 As shown, the composite functional coating also includes a transparent low surface energy sealing layer, which is disposed on the modified DLC functional layer. The sealing layer on the modified DLC can reduce the entry of oil, salt, and moisture into micro-defects, improving initial non-stick properties and ease of cleaning.

[0038] In a preferred embodiment of the present invention, the modified DLC functional layer has a different thickness in different regions of the inner surface of the cookware.

[0039] In a preferred embodiment of the present invention, the modified DLC functional layer has a thickness of 1.2-2.5 μm in the central region of the pot bottom, 0.8-2 μm in the transition region of the pot bottom, 0.5-1.2 μm in the sidewall region, and 0.3-1 μm in the rim region. The modified DLC functional layer has varying thicknesses in different regions of the inner surface of the cookware. Specifically, the modified DLC functional layer has a thickness of 1.2-2.5 μm in the central region of the pot bottom, 0.8-2 μm in the transition region of the pot bottom, 0.5-1.2 μm in the sidewall region, and 0.3-1 μm in the rim region. The inner surface of the cookware is precision polished or micro-textured before the modified DLC functional layer is formed. Preferably, the surface roughness of the food contact surface after the modified DLC functional layer is formed is Ra 0.02-0.60 μm, more preferably Ra 0.05-0.30 μm.

[0040] In a preferred embodiment of the present invention, the transparent low surface energy sealing layer includes one or more of SiOxCy, SiCN, SiOxNy, siloxane sol-gel layer, methylsiloxane modified layer, fluorosilane modified layer, fluorine-containing transparent ceramic hybrid layer, or silicon / fluorine-containing organic-inorganic hybrid layer.

[0041] In a preferred embodiment of the present invention, the thickness of the transparent low surface energy sealing layer is 20 nm-2 μm.

[0042] In a preferred embodiment of the present invention, the thickness of the transparent low surface energy sealing layer is 80 nm-300 nm. The transparent low surface energy sealing layer is used to improve initial non-stick properties, seal micropores and micro-defects on the surface of the DLC layer, reduce the possibility of oil, salt, and moisture entering the film layer defects, and slow down the non-stick degradation caused by long-term cooking and washing. The transparent low surface energy sealing layer includes one or more of SiOxCy, SiCN, SiOxNy, siloxane sol-gel layer, methylsiloxane modified layer, fluorosilane modified layer, fluorine-containing transparent ceramic hybrid layer, or silicon / fluorine-containing organic-inorganic hybrid layer. The thickness of the transparent low surface energy sealing layer is 20 nm-2 μm, preferably 50-800 nm, and more preferably 80-300 nm.

[0043] In a preferred embodiment of the present invention, the modified DLC functional layer includes one or more of silicon-containing DLC, fluorine-containing DLC, silicon / fluorine co-doped DLC, hydrogen-containing DLC, or hydrogen-free DLC. The modified DLC functional layer is the main wear-resistant and low-adhesion functional layer on the inner surface of the cookware. The modified DLC functional layer includes one or more of silicon-containing DLC ​​(Si-DLC), fluorine-containing DLC ​​(F-DLC), silicon / fluorine co-doped DLC (Si / F-DLC), hydrogen-containing DLC ​​(aC:H), hydrogen-free DLC, or multilayer alternating DLC. Preferably, the modified DLC functional layer is Si-DLC, F-DLC, or Si / F co-doped DLC. The thickness of the modified DLC functional layer is 0.3-5 μm, preferably 0.8-2 μm. Its surface hardness is 800-3000 HV. The water contact angle of the food contact surface is preferably greater than 85°, more preferably greater than 95°; the surface energy is preferably less than 40 mN / m, more preferably less than 30 mN / m.

[0044] In a preferred embodiment of the present invention, the surface support layer includes one or more of the following: a nitrided layer, a carburized layer, a nitrocarburized layer, a hard anodized layer, a micro-arc oxidation layer, an ion implantation reinforced layer, or a ceramicized surface layer. The surface support layer is used to improve the surface hardness of the cookware substrate, reduce the hardness abrupt change between the DLC hard film and the soft substrate, and improve coating adhesion and thermal cycling stability. The surface support layer can be one or more of the following: a nitrided layer, a carburized layer, a nitrocarburized layer, a hard anodized layer, a micro-arc oxidation layer, an ion implantation reinforced layer, or a ceramicized surface layer. Preferably, when the substrate is stainless steel, the surface support layer is a low-temperature nitrided layer or a nitrocarburized layer with a thickness of 5-50 μm and a surface hardness of 600-1200 HV.

[0045] In a preferred embodiment of the present invention, the metal transition layer is made of Ti, Cr, W, Mo, Zr, Si, Nb, Ta, or an alloy of the above elements. The metal transition layer is disposed between the surface support layer and the gradient bonding layer to improve the adhesion between the substrate and the DLC functional layer. The metal transition layer material includes Ti, Cr, W, Mo, Zr, Si, Nb, Ta, or an alloy of the above elements. The thickness of the metal transition layer is preferably 0.05-3 μm, more preferably 0.1-1 μm.

[0046] In a preferred embodiment of the present invention, the gradient bonding layer includes one or more of the following: a metal carbide layer, a metal carbonitride layer, a Si-CN gradient layer, a Si-CO gradient layer, TiC, CrC, WC, SiC, TiCN, and CrCN. The gradient bonding layer is disposed between the metal transition layer and the modified DLC functional layer to alleviate internal stress and thermal expansion differences within the film. The gradient bonding layer can be one or more of the following: a metal carbide layer, a metal carbonitride layer, a Si-CN gradient layer, a Si-CO gradient layer, TiC, CrC, WC, SiC, TiCN, and CrCN. Preferably, the carbon content in the gradient bonding layer gradually increases from the side closer to the metal transition layer to the side closer to the DLC functional layer. The thickness of the gradient bonding layer is preferably 0.05-2 μm.

[0047] In a preferred embodiment of the present invention, the carbon content in the gradient bonding layer gradually increases from the side closer to the metal transition layer to the side closer to the modified DLC functional layer.

[0048] The cookware of the present invention can significantly improve the adhesion and anti-peeling performance of the coating under hot and cold cyclic cooking conditions, while having excellent scratch resistance and low adhesion (non-stick) performance, thus improving the product's cost-effectiveness and overall reliability.

[0049] A second aspect of the embodiments of the present invention provides a method for preparing wear-resistant and low-adhesion cookware, such as... Figure 2 As shown, it includes the following steps: S1: (a) A surface support layer is formed after pretreatment of the cookware substrate surface. The cookware substrate is made of stainless steel, titanium alloy, aluminum alloy or composite metal sheet; a surface support layer is formed after pretreatment of the inner surface of the cookware substrate; the pretreatment includes degreasing, cleaning, deoxidation, precision polishing or microtexturing, and the roughness is preferably controlled to Ra 0.02-0.50μm; the formation of the surface support layer includes low-temperature plasma nitriding, gas nitriding, ion nitrocarburizing, hard anodizing, micro-arc oxidation or ceramic treatment selected according to different substrates.

[0050] S2: (b) The cookware with the surface support layer is placed in the PVD+PACVD / PECVD composite vacuum coating equipment to remove contaminants from the cookware and activate the surface. Under vacuum conditions, a metal transition layer and a gradient bonding layer are deposited sequentially on the surface support layer. S3: (c) In the same vacuum chamber, while maintaining a vacuum state, a modified DLC functional layer is formed on the gradient bonding layer by plasma-enhanced chemical vapor deposition or plasma-assisted chemical vapor deposition. The multi-layer stacking and formation in the same device can improve hardness and at the same time reduce the coefficient of friction and food adhesion. S4: (d) A transparent low surface energy sealing layer is formed on the modified DLC functional layer, which can reduce the entry of oil, salt and water vapor into micro-defects and improve initial non-stick and easy cleaning.

[0051] In a preferred embodiment of the present invention, the parameters in step (c) are as follows: the ultimate vacuum of the vacuum chamber is 1×10⁻⁶. -3 -5×10 -2 The working pressure is 0.1-10 Pa, the workpiece bias voltage is -50 to -1000 V, the workpiece temperature is 80-350℃, the rotating frame speed is 1-20 rpm, the plasma power is 0.5-20 kW, the deposition time is 20-240 min, and the DLC film thickness is 0.3-5 μm.

[0052] In a preferred embodiment of the present invention, the parameters in step (c) are as follows: the ultimate vacuum of the vacuum chamber is 1×10⁻⁶. -3 -1×10 -2 The working pressure is 0.3-3 Pa, the workpiece bias voltage is -100 to -600 V, the workpiece temperature is 120-250℃, the rotating frame speed is 3-10 rpm, the plasma power is 2-10 kW, the deposition time is 45-150 min, and the DLC film thickness is 0.8-2 μm.

[0053] In a preferred embodiment of the present invention, the process gas used includes a carbon source gas, a silicon source gas, and / or a fluorine source gas; the carbon source gas includes one or more of CH4 and C2H2; the silicon source gas includes TMS or HMDSO, accounting for 2-10% of the total flow rate of the reaction gas; the fluorine source gas includes one or more of CF4, C2F6, CHF3, fluorinated silanes, and perfluoroalkyl silanes, accounting for 0.5-5% of the total flow rate of the reaction gas.

[0054] In a preferred embodiment of the present invention, step (c) further includes rotating the pot in the vacuum chamber at a speed of 1-20 rpm and using an internal surface directional plasma source, auxiliary electrode or an annular gas distribution structure to improve the uniformity of the film thickness on the inner wall of the pot, so that the uniformity of the film thickness on the inner wall of the pot reaches within ±30%.

[0055] In a preferred embodiment of the present invention, step (c) further includes rotating the pot in the vacuum chamber at a speed of 3-10 rpm and using an internal surface directional plasma source, auxiliary electrode or an annular gas distribution structure to improve the uniformity of the film thickness on the inner wall of the pot, so that the uniformity of the film thickness on the inner wall of the pot reaches within ±15%.

[0056] In a preferred embodiment of the present invention, in step (d), the transparent low surface energy sealing layer is formed by PECVD or PACVD process, with the following process parameters: workpiece temperature of 120-220℃, working pressure of 0.5-3Pa, bias voltage of -50 to -250V, plasma power of 0.5-5KW, deposition time of 10-30min, and the gas used includes one or more of HMDSO, TMS, TEOS, O2, N2, Ar, CF4 and fluorinated silanes.

[0057] In a preferred embodiment of the present invention, in step (d), the transparent low surface energy sealing layer is formed by a sol-gel method, including the following steps: (1) Prepare a sol containing silane precursor, alcohol solvent, deionized water and low surface energy modifier; (2) The sol is coated onto the surface of the modified DLC functional layer by an automatic atomization spraying method; (3) Curing at 180-260℃ for 20-40 min yields a sealing layer with a thickness of 80-800 nm; Preferably, the silane precursor is methyltrimethoxysilane or tetraethyl orthosilicate, and the low surface energy modifier is perfluoroalkylsilane or methylsiloxane resin.

[0058] In a preferred embodiment of the present invention, the method further includes the following steps prior to the step of forming a transparent low surface energy sealing layer on the modified DLC functional layer: The modified DLC functional layer was activated by low-power O2 or Ar plasma for 1-10 min at 60-180℃.

[0059] Example 1: The cookware substrate is a pure titanium wok, with an inner surface roughness Ra of 0.20 μm after precision polishing. A surface support layer is formed on the inner surface of the cookware using a sandblasting process. Subsequently, a Cr metal transition layer with a thickness of 0.05 μm is deposited using a magnetron sputtering process. A CrC gradient bonding layer with a thickness of 0.05 μm is formed on the Cr transition layer by gradually introducing CH4 gas, with the carbon content gradually increasing from the side closer to the metal transition layer to the side farther away.

[0060] The aforementioned cookware was placed into a PECVD vacuum coating equipment, and a vacuum was drawn to an ultimate vacuum of 5×10⁻⁶. -2The workpiece was heated to 80°C. Ar and CH4 gases were introduced, the working pressure was controlled at 0.1 Pa, a workpiece bias voltage of -50 V was applied, the rack speed was 1 rpm, the plasma power was 0.5 kW, and the deposition time was 20 min to form a hydrogen-free DLC functional layer with a thickness of 0.3 μm and a surface hardness of approximately 800 HV.

[0061] The sealing layer was prepared using a sol-gel method, with the following siloxane sol composition: 30 wt% methyltrimethoxysilane (MTMS), 10 wt% tetraethyl orthosilicate (TEOS), 50 wt% ethanol, 8 wt% deionized water, and 1 wt% hydrochloric acid catalyst, with 3 wt% perfluoroalkylsilane added as a low surface energy modifier. The sol was applied to the DLC layer surface using an automated atomizing spray method: spray gun pressure 0.3 MPa, distance 200 mm, atomizing air pressure 0.25 MPa, pot rotation speed 30 rpm, single wet film thickness 5 μm, two coats, leveling at room temperature for 10 min, pre-drying at 80℃ for 15 min, and then curing at 240℃ for 30 min. The cured sealing layer thickness was approximately 300 nm, and the material was a methylsiloxane / fluorosilane hybrid layer.

[0062] The resulting cookware has a water contact angle of 102° on its inner surface.

[0063] Example 2: The cookware substrate is a 304 stainless steel wok with a surface roughness Ra of 0.20 μm after precision polishing. A low-temperature plasma nitriding layer with a thickness of 5 μm and a surface hardness of 600 HV is formed on the inner surface of the cookware as a surface support layer. Then, a Ti metal transition layer with a thickness of 3 μm is deposited using multi-arc ion plating. A TiC gradient bonding layer with a thickness of 2 μm is then deposited, with the carbon content gradually increasing from the side closer to the metal transition layer to the side farther away.

[0064] Place the cookware into the PACVD vacuum equipment and evacuate to the ultimate vacuum of 1×10⁻⁶. -3 Pa, heated to 250℃. C2H2 and Ar were introduced, the working pressure was 10 Pa, a workpiece bias voltage of -1000 V was applied, the rack speed was 20 rpm, the plasma power was 20 kW, and the deposition time was 240 min, forming a hydrogen-free DLC functional layer with a thickness of 5.0 μm and a surface hardness of approximately 3000 HV.

[0065] The sealing layer employs a high nanoparticle content sol-gel formulation. The sol-gel composition is: 60 wt% silane precursor (MTMS+TEOS mixture), 30 wt% ethanol, 7 wt% deionized water, 2 wt% hydrochloric acid catalyst, 10 wt% perfluoroalkyl silane, and 10 wt% nano-SiO2 particles. The coating process is as follows: spray gun pressure 0.5 MPa, distance 150 mm, atomizing air pressure 0.4 MPa, pot rotation speed 50 rpm, single wet film thickness 8 μm, 3 coats. Leveling is allowed for 20 min, pre-drying at 100℃ for 20 min, followed by curing at 220℃ for 40 min. The cured sealing layer thickness is approximately 650 nm.

[0066] The resulting cookware has a water contact angle of 110°, the DLC layer is dense and hard, and there is no cracking after the gradient bonding layer is applied.

[0067] Example 3: The cookware substrate is made of aluminum alloy. First, an aluminum oxide surface support layer with a thickness of 40 μm and a hardness of 450 HV is formed on the inner surface of the aluminum alloy through hard anodizing. Then, a Ti metal transition layer with a thickness of 3 μm is deposited using multi-arc ion plating. Next, a TiC gradient bonding layer with a thickness of 2 μm is deposited, with the carbon content gradually increasing from the side closer to the metal transition layer to the side farther away.

[0068] The cookware is placed in a PVD+PECVD composite vacuum apparatus, and subsequent depositions are completed continuously within the same chamber. The vacuum is then evacuated to an ultimate vacuum of 1×10⁻⁶. -2 Pa, heated to 190℃. CH4, TMS, and Ar were introduced at flow rates of 200 sccm, 30 sccm, and 150 sccm, respectively (TMS accounted for approximately 8% of the total reactant gas flow rate). The working pressure was 1.2 Pa, a workpiece bias voltage of -300 V was applied, the rack speed was 6 rpm, the plasma power was 5 kW, and the deposition time was 90 min, forming a Si-DLC functional layer with a thickness of 1.2 μm, a surface hardness of 1800 HV, and a water contact angle of 98°.

[0069] The sealing layer was prepared using a sol-gel method, with the following siloxane sol composition: 32 wt% methyltrimethoxysilane (MTMS), 11 wt% tetraethyl orthosilicate (TEOS), 40 wt% ethanol, 10 wt% deionized water, and 1.2 wt% hydrochloric acid catalyst. 4 wt% perfluoroalkylsilane was added as a low surface energy modifier. The sol was applied to the DLC layer surface using an automated atomizing spray method: spray gun pressure 0.4 MPa, distance 220 mm, atomizing air pressure 0.3 MPa, pot rotation speed 40 rpm, single wet film thickness 6 μm, two coats, leveling at room temperature for 15 min, pre-drying at 90℃ for 20 min, and then curing at 200℃ for 35 min. The cured sealing layer thickness was approximately 600 nm, and the material was a methylsiloxane / fluorosilane hybrid layer.

[0070] The final water contact angle on the inner surface of the cookware is 108°.

[0071] Example 4: The cookware substrate is an iron wok, with the inner surface precision polished to Ra 0.10μm. A low-temperature nitrocarburization surface support layer with a thickness of 20μm and a surface hardness of 950 HV is formed. A Cr metal transition layer with a thickness of 0.3μm is deposited using a PVD process. Then, a CrC / Si-CN gradient bonding layer with a thickness of 0.5μm is deposited, with the carbon content gradually increasing from the side closer to the metal transition layer to the side farther away.

[0072] F-DLC functional layers were deposited using PACVD equipment, with subsequent depositions completed continuously within the same chamber. Ultimate vacuum: 1×10⁻⁶. -2 The conditions were: Pa, workpiece temperature 170℃, working pressure 1.0 Pa, applied bias voltage -250V, rack speed 5 rpm, plasma power 3 kW, and deposition time 70 min. The gases were CH4 (200 sccm), CF4 (20 sccm, approximately 4% of the total reactant gas flow rate), and Ar (180 sccm). An F-DLC layer with a thickness of 1.0 μm and a water contact angle of 108° was formed.

[0073] The sealing layer employs a high nanoparticle content sol-gel formulation. The sol-gel composition is as follows: 55 wt% silane precursor (MTMS+TEOS mixture), 35 wt% ethanol, 8 wt% deionized water, 1.8 wt% hydrochloric acid catalyst, 9 wt% perfluoroalkyl silane, and 9 wt% nano-SiO2 particles. The coating process is as follows: spray gun pressure 0.5 MPa, distance 200 mm, atomizing air pressure 0.35 MPa, pot rotation speed 55 rpm, single wet film thickness 7 μm, 3 coats. Leveling is allowed for 20 min, pre-drying at 90℃ for 25 min, followed by curing at 230℃ for 35 min. The cured sealing layer thickness is approximately 700 nm.

[0074] The final water contact angle of the cookware is 115°.

[0075] Example 5: The cookware substrate is a pure titanium wok, and the surface support layer, metal transition layer, and gradient bonding layer are the same as in Example 1.

[0076] A Si / F co-doped DLC functional layer was deposited using a PVD+PACVD composite equipment. The workpiece temperature was 200℃, the working pressure was 1.5Pa, a -350V bias voltage was applied, the rack speed was 8rpm, the plasma power was 6kW, and the deposition time was 120min. The carbon source was a CH4+C2H2 mixture (150 sccm each), the silicon source was TMS (40 sccm, approximately 6% of the total reactant gas flow), the fluorine source was CF4 (15 sccm, approximately 2.5%), and the Ar source was 250 sccm. Differential thicknesses were achieved by controlling the plasma exposure intensity in different regions of the pot during deposition: 2.0μm in the center region of the pot bottom, 1.2μm in the transition region of the pot bottom, 0.8μm in the sidewall region, and 0.5μm in the rim region, with a surface energy below 30 mN / m.

[0077] The sealing layer was formed using PECVD process with TMS, O2 and Ar as reactant gases (flow ratio 2:1:12), workpiece temperature 200℃, working pressure 1Pa, applied bias voltage of -250 V, plasma power of 2kW, and deposition time of 20 min, forming a 2.0μm thick SiOxCy transparent low surface energy sealing layer.

[0078] The final water contact angle of the cookware is 105°. The differentiated thickness design significantly improves the wear resistance of the bottom of the pot, reduces the stress on the side walls, and extends the overall service life.

[0079] Example 6: The cookware substrate is a 304 stainless steel wok. The surface support layer, metal transition layer, and gradient bonding layer are the same as in Example 2. The Si-DLC functional layer (thickness 1.2μm) is prepared in the same way as in Example 3.

[0080] The sealing layer was created using PECVD with HMDSO, CF4, and Ar as reactants (flow ratio 15:10:150). The workpiece temperature was 160℃, the working pressure was 1.8 Pa, a -200V bias voltage was applied, the plasma power was 2 kW, and the deposition time was 15 min, forming a 120 nm thick fluorine-doped SiOxCy transparent low surface energy sealing layer. This cookware exhibits extremely low surface energy and excellent non-stick properties, making it suitable for frying and other cooking methods.

[0081] The final water contact angle of the cookware is 112°, and it is completely transparent in appearance.

[0082] Example 7: The cookware substrate is made of aluminum alloy. The surface support layer, metal transition layer and gradient bonding layer are the same as in Example 3. The F-DLC functional layer (thickness 1.0 μm) is prepared in the same way as in Example 4.

[0083] The sealing layer was formed by PECVD with the following parameters: gas HMDSO+O2+Ar, workpiece temperature 160℃, working pressure 1.0Pa, applied bias voltage of -120V, plasma power of 1.8kW, and deposition time of 18min, forming a fluorine-doped SiOxCy transparent low surface energy sealing layer with a thickness of 130nm.

[0084] The final water contact angle of the cookware is 103°.

[0085] Example 8: The cookware substrate is an iron wok, with the inner surface precisely polished to Ra 0.10μm. The surface support layer, metal transition layer, and gradient bonding layer are the same as in Example 4, and Si-DLC (Si-DLC, thickness 1.2μm) is deposited in the same way as in Example 3.

[0086] The sealing layer was formed by PECVD with the following parameters: gas HMDSO+O2+Ar, workpiece temperature 160℃, working pressure 1.0Pa, applied bias voltage of -120V, plasma power of 1.8kW, and deposition time of 18min, forming a fluorine-doped SiOxCy transparent low surface energy sealing layer with a thickness of 130nm.

[0087] The final water contact angle of the cookware is 106°.

[0088] Example 9: The cookware substrate is a stainless steel wok. A surface support layer is formed on the inner surface of the cookware using a cold spray process. Subsequently, a Cr metal transition layer with a thickness of 0.06 μm is deposited using a magnetron sputtering process. A CrC gradient bonding layer with a thickness of 0.06 μm is formed on the Cr transition layer by gradually introducing CH4 gas, with the carbon content gradually increasing from the side closer to the metal transition layer to the side farther away. DLC is prepared in the same manner as in Example 3. The sealing layer is prepared using PACVD: gas TMS+O2+Ar, workpiece temperature 220℃, working pressure 2.0 Pa, applied bias voltage -220 V, plasma power 4 kW, deposition time 25 min, and thickness 250 nm.

[0089] The final water contact angle of the cookware is 109°.

[0090] Example 10: The cookware substrate is an aluminum wok, and a surface support layer is formed on the inner surface of the cookware using a cold spray process. Subsequently, a Cr metal transition layer with a thickness of 0.05 μm is deposited using magnetron sputtering. A CrC gradient bonding layer with a thickness of 0.05 μm is formed on the Cr transition layer by gradually introducing CH4 gas, with the carbon content gradually increasing from the side closer to the metal transition layer to the side farther away. DLC is prepared in the same manner as in Example 3. The sealing layer is prepared using PACVD: gas HMDSO+CF4+Ar, workpiece temperature 140℃, working pressure 0.8 Pa, applied bias voltage -80 V, plasma power 1.2 kW, deposition time 12 min, and a thickness of 80 nm.

[0091] The final water contact angle of the cookware is 110°.

[0092] The performance test data of Examples 1-10 are summarized in Table 1 below: 1 Hydrogen-free DLC Sol-gel hybrid layer (300nm) 102 No peeling No exposed bottom 2 Hydrogen-free DLC Sol-gel high particle size (650nm) 110 No peeling No exposed bottom 3 Si-DLC Sol-gel hybrid layer (400nm) 108 No peeling No exposed bottom 4 F-DLC Sol-gel high particle size (700nm) 115 No peeling No exposed bottom 5 Si / F-DLC PECVD SiOxCy (2μm) 105 No peeling No exposed bottom 6 Si-DLC PECVD SiOxCy (120nm) 112 No peeling No exposed bottom 7 F-DLC PECVD SiOxCy (130nm) 103 No peeling No exposed bottom 8 Si-DLC PECVD SiOxCy (130nm) 106 No peeling No exposed bottom 9 Si-DLC PACVD SiOxCy (250nm) 109 No peeling No exposed bottom 10 Si-DLC PACVD with fluorine-containing SiOxCy (80nm) 110 No peeling No exposed bottom

[0093] Table 1 Summary of Performance Test Data The cookware prepared by the method of the present invention can significantly improve the adhesion and anti-peeling performance of the coating under hot and cold cyclic cooking conditions, while having excellent scratch resistance and low adhesion (non-stick) performance, thus improving the product's cost-effectiveness and overall reliability.

[0094] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

[0095] It should be understood that, as used herein, the singular form "a" is intended to include the plural form as well, unless the context clearly supports an exception. The embodiment numbers disclosed above are for descriptive purposes only and do not represent any superiority or inferiority of the embodiments.

[0096] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention (including the claims) is limited to these examples. Within the framework of the invention, technical features of the above embodiments or different embodiments can be combined, and many other variations of different aspects of the invention exist, which are not provided in the details for the sake of brevity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the invention should be included within the protection scope of the invention.

Claims

1. A wear-resistant and low-adhesion cookware, characterized in that, The cookware substrate includes a composite functional coating formed on at least its inner surface. The composite functional coating includes, from the side closest to the cookware substrate to the side furthest from the cookware substrate, a surface support layer, a metal transition layer, a gradient bonding layer, and a modified DLC functional layer.

2. The wear-resistant and low-adhesion cookware according to claim 1, characterized in that, The composite functional coating also includes a transparent low surface energy sealing layer, which is disposed on the modified DLC functional layer.

3. The wear-resistant and low-adhesion cookware according to claim 1 or 2, characterized in that, The modified DLC functional layer has varying thicknesses in different areas of the inner surface of the cookware.

4. The wear-resistant and low-adhesion cookware according to any one of claims 1-3, characterized in that, The thickness of the modified DLC functional layer is 1.2-2.5 μm in the central region of the bottom of the pot, 0.8-2 μm in the transition region of the bottom of the pot, 0.5-1.2 μm in the side wall region, and 0.3-1 μm in the rim region of the pot.

5. The wear-resistant and low-adhesion cookware according to any one of claims 2-4, characterized in that, Transparent low surface energy sealing layers include one or more of the following: SiOxCy, SiCN, SiOxNy, siloxane sol-gel layers, methylsiloxane modified layers, fluorosilane modified layers, fluorine-containing transparent ceramic hybrid layers, or silicon / fluorine-containing organic-inorganic hybrid layers.

6. The wear-resistant and low-adhesion cookware according to any one of claims 2-5, characterized in that, The thickness of the transparent low surface energy sealing layer is 20nm-2μm.

7. The wear-resistant and low-adhesion cookware according to any one of claims 2-5, characterized in that, The thickness of the transparent low surface energy sealing layer is 80nm-300nm.

8. The wear-resistant and low-adhesion cookware according to any one of claims 1-7, characterized in that, The modified DLC functional layer includes one or more of the following: silicon-containing DLC, fluorine-containing DLC, silicon / fluorine co-doped DLC, hydrogen-containing DLC, or hydrogen-free DLC.

9. The wear-resistant and low-adhesion cookware according to any one of claims 1-8, characterized in that, The surface support layer includes one or more of the following: nitrided layer, carburized layer, nitrocarbon co-diffusion layer, hard anodized layer, micro-arc oxidation layer, ion implantation strengthening layer, or ceramicized surface layer.

10. The wear-resistant and low-adhesion cookware according to any one of claims 1-9, characterized in that, The materials for the metal transition layer include Ti, Cr, W, Mo, Zr, Si, Nb, Ta, or alloys of the above elements.

11. The wear-resistant and low-adhesion cookware according to any one of claims 1-10, characterized in that, The gradient bonding layer includes one or more of the following: metal carbide layer, metal carbonitride layer, Si-CN gradient layer, Si-CO gradient layer, TiC, CrC, WC, SiC, TiCN, and CrCN.

12. The wear-resistant and low-adhesion cookware according to any one of claims 1-11, characterized in that, The carbon content in the gradient bonding layer gradually increases from the side closer to the metal transition layer to the side closer to the modified DLC functional layer.

13. A method for preparing wear-resistant and low-adhesion cookware, characterized in that, Includes the following steps: (a) A surface support layer is formed after pretreatment of the cookware substrate surface; (b) The cookware with the surface support layer is placed in the PVD+PACVD / PECVD composite vacuum coating equipment to remove contaminants from the cookware and activate the surface. Under vacuum conditions, a metal transition layer and a gradient bonding layer are deposited sequentially on the surface support layer. (c) In the same vacuum chamber, while maintaining a vacuum state, a modified DLC functional layer is formed on the gradient bonding layer by plasma-enhanced chemical vapor deposition or plasma-assisted chemical vapor deposition. (d) A transparent low surface energy sealing layer is formed on the modified DLC functional layer.

14. The method according to claim 13, characterized in that, The parameters in step (c) are as follows: the ultimate vacuum of the vacuum chamber is 1×10⁻⁶. -3 -5×10 -2 The working pressure is 0.1-10 Pa, the workpiece bias voltage is -50 to -1000 V, the workpiece temperature is 80-350℃, the rotating frame speed is 1-20 rpm, the plasma power is 0.5-20 kW, the deposition time is 20-240 min, and the DLC film thickness is 0.3-5 μm.

15. The method according to claim 14, characterized in that, The parameters in step (c) are as follows: the ultimate vacuum of the vacuum chamber is 1×10⁻⁶. -3 -1×10 -2 The working pressure is 0.3-3 Pa, the workpiece bias voltage is -100 to -600 V, the workpiece temperature is 120-250℃, the rotating frame speed is 3-10 rpm, the plasma power is 2-10 kW, the deposition time is 45-150 min, and the DLC film thickness is 0.8-2 μm.

16. The method according to any one of claims 13-15, characterized in that, The process gases used include carbon source gases, silicon source gases and / or fluorine source gases; carbon source gases include one or more of CH4 and C2H2; silicon source gases include TMS or HMDSO, accounting for 2-10% of the total flow rate of the reaction gases; fluorine source gases include one or more of CF4, C2F6, CHF3, fluorinated silanes and perfluoroalkyl silanes, accounting for 0.5-5% of the total flow rate of the reaction gases.

17. The method according to any one of claims 13-16, characterized in that, Step (c) also includes rotating the pot in the vacuum chamber at a speed of 1-20 rpm and using an internal surface directional plasma source, auxiliary electrode or annular gas distribution structure to improve the uniformity of the film thickness inside the pot, so that the uniformity of the film thickness inside the pot reaches within ±30%.

18. The method according to any one of claims 13-17, characterized in that, Step (c) also includes rotating the pot in the vacuum chamber at a speed of 3-10 rpm and using an internal surface directional plasma source, auxiliary electrode or annular gas distribution structure to improve the uniformity of the film thickness inside the pot, so that the uniformity of the film thickness inside the pot reaches within ±15%.

19. The method according to any one of claims 13-18, characterized in that, In step (d), the transparent low surface energy sealing layer is formed by PECVD or PACVD process, with the following process parameters: workpiece temperature 120-220℃, working pressure 0.5-3Pa, bias voltage -50 to -250V, plasma power 0.5-5KW, deposition time 10-30min, and the gases used include one or more of HMDSO, TMS, TEOS, O2, N2, Ar, CF4 and fluorinated silanes.

20. The method according to any one of claims 13-19, characterized in that, In step (d), the transparent low surface energy sealing layer is formed by the sol-gel method, including the following steps: (1) Prepare a sol containing silane precursor, alcohol solvent, deionized water and low surface energy modifier; (2) The sol is coated onto the surface of the modified DLC functional layer by an automatic atomization spraying method; (3) Curing at 180-260℃ for 20-40 min yields a sealing layer with a thickness of 80-800 nm; The silane precursor is methyltrimethoxysilane or tetraethyl orthosilicate, and the low surface energy modifier is perfluoroalkylsilane or methylsiloxane resin.

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