Aluminum magnesium boride-based coatings for cookware

Abstract

Articles of cookware are disclosure herein including an aluminum magnesium boride (AlMgB14) coating. The AlMgB14 layer advantageously imparts non-stick properties to the article of cookware at a level superior to conventional polytetrafluoroethylene (PTFE) with a surface hardness over 45,000% greater than PTFE-based non-stick coatings and a thermal stability over 340% greater than PTFE-based non-stick coatings.

Description

ALUMINUM MAGNESIUM BORIDE-BASED COATINGS FOR COOKWARECROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Patent Application No. 63 / 571,781, filed March 29, 2024, and U.S. Provisional Patent Application No. 63 / 692,949, filedSeptember 10, 2024, both of which are incorporated herein in their entirety.TECHNICAL FIELD

[0002] The present disclosure is generally in the field of cookware, and particularly related to cookware with aluminum magnesium boride coatings.BACKGROUND

[0003] Non-stick cookware has been a mainstay of kitchens worldwide for nearly 100 years. Preventing or reducing adhesion or stickiness of food as it cooks in cookware can enhance food texture, meal presentation, and the clean-up associated with cooking. Although spraying or melting a fatty substance in a piece of cookware when cooking food can produce a non-stick effect, many modem non-stick cookware rely on a non-stick coating that is applied during cookware production.

[0004] Conventional non-stick cookware utilizes polytetrafluoroethylene (PTFE), such as the TEFLON® brand of non-stick coating. PTFE is known for its low reactivity and low coefficient of friction (0.05 - 0.20), making it a favorable candidate for non-stick cookware. However, PTFE is a perfluoroalkyl substance (PF AS), a class of chemicals which have come to be known as “forever chemicals” due to their inability to degrade or break down via natural process. As a result of increased scrutiny into the effect of PFAS on human health, PFAS have been the subjectof increasing regulatory efforts to reduce use and reduce waste. As such, there has been increased efforts at developing alternatives to PTFE for use on non-stick cookware.

[0005] A common alternative to PTFE for use on non-stick cookware includes a silica-based coating called sol-gel, sometimes referred to as simply a “ceramic coating,” so named for the method of gelling of a colloidal solution of silica particles. Although these silica-based ceramic coatings generally have coefficient of friction comparable to or lower than PTFE-based coatings, the sol-gel coating includes a silicone-based oil that has a limited life-span, on the order of around 12 months, before the oil is “consumed” and the cookware no longer possesses any nonstick properties. Furthermore, silica-based ceramic coatings fail to improve on PTFE-based coating’s thermal stability, breaking down at between about 475°F to 500°F compared to around 500°F for PTFE coatings.

[0006] Finally, PTFE-based coatings are notorious for their poor strength; consumers are warned and conditioned to avoid using metal utensils in order to extend the life of the PTFE- based coating and to avoid damaging the PTFE-based coating. Damaging the PTFE-based coating compromises the non-stick properties of the cookware, exposes the cookware base material, and releases microparticles of PTFE into cooked food.

[0007] Accordingly, it can be seen that improved non-stick coatings are needed for overcoming one or more of the technical challenges described above. The present disclosure addresses these and other related and other related issues in the art.SUMMARY

[0008] In embodiments, the present disclosure describes an article of cookware having a nonstick coating, the non-stick coating including aluminum magnesium boride (AlMgBu). In embodiments, the article of cookware includes one or more layers, each of the one or more layersincluding stainless-steel or stainless-steel alloy, aluminum or aluminum alloy, cast iron, or anodized aluminum. In embodiments, the non-stick coating has a thickness of from about 0.1 microns to about 50 microns, such as from about 0.5 microns to about 10 microns.

[0009] In embodiments, the article of cookware includes an adhesion layer between the article of cookware and the non-stick coating. In embodiments, the adhesion layer includes titanium or chromium and has a thickness of from about 1 micron to about 5 microns.

[0010] In embodiments, the non-stick coating further includes an additive, and the additive may include silicon, phosphorus, titanium alloys such as titanium diboride or titanium carbide, or nitrides such as aluminum nitride or boron nitride.

[0011] In embodiments, the article of cookware includes a surface energy improvement treatment on top of the non-stick coating, wherein the surface energy improvement treatment comprises a functionalized silane layer, a polymer-based layer, a blend of AlMgBu and a polymer coating, acid etching, laser irradiation, plasma treatment, laser ablative patterning, thermal annealing, or the like. In embodiments in which a functionalized silane layer is present, the functionalized silane layer comprises octyltrichlorosilane, hexyltrichlorosilane, decyltrichlorosilane, dodecyltrichlorosilane, methyltrichlorosilane, phenyltrichlorosilane, vinyltrichlorosilane, or the like.

[0012] In embodiments, the article of cookware is a cooking pot, a pan, a non-stick reservoir for a kitchen appliance, a cooling rack, a kitchen appliance rack, or the like.

[0013] In embodiments, the present disclosure describes a method of making an article of cookware having a non-stick coating, the method including providing an uncoated article of cookware, and coating the article of cookware with one or more layers of aluminum magnesiumboride (AlMgBu). In embodiments, coating the article of cookware comprises physical vapor deposition (PVD), sputter coating, arc sputtering, or laser powder deposition (LPD).

[0014] In embodiments, the methods include treating a surface of the article of cookware before coating the article of cookware with AlMgBu. In embodiments, treating the surface of the article of cookware includes acid etching, laser irradiation, plasma treatment, laser ablative patterning, thermal annealing, or coating the surface with a functionalized silane layer.

[0015] In embodiments, the methods include coating the article of cookware with an adhesion layer before coating the article of cookware with AlMgBu. In embodiments, the adhesion layer includes titanium or chromium.

[0016] In embodiments, the methods include treating the non-stick layer with a surface energy improvement treatment. In embodiments, treating the non-stick layer includes depositing a functionalized silane layer, depositing a polymer-based layer, depositing a coating including a blend of AlMgBu and a polymer, acid etching, laser irradiation, plasma treatment, laser ablative patterning, thermal annealing, or the like.BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The detailed description is set forth with reference to the accompanying drawings. The use of the same reference numerals may indicate similar or identical items. Various embodiments may utilize elements and / or components other than those illustrated in the drawings, and some elements and / or components may not be present in various embodiments. Elements and / or components in the figures are not necessarily drawn to scale. Throughout this disclosure, depending on the context, singular’ and plural terminology may be used interchangeably.

[0018] FIGS. 1A-1B depict a pan with a PTFE-coated interior surface in the prior art.

[0019] FIGS. 2A-2B depict an AlMgB 14-coated pan in accordance with the present disclosure.

[0020] FIG. 3 depicts a cross-sectional view of AlMgB 14-coated cookware in accordance with the present disclosure.

[0021] FIG. 4 depicts a cross-sectional view of a multi-ply AlMgB 14-coated cookware in accordance with the present disclosure.

[0022] The present disclosure provides a more detailed and specific description with reference to the accompanying drawings. The drawings and specific descriptions of the drawings, as well as any specific or other embodiments discussed, are intended to be read in conjunction with the entirety of this disclosure.DETAILED DESCRIPTION

[0023] Example embodiments will now be described more fully hereinafter with reference to the accompanying drawings, in which example embodiments are shown. The concepts disclosed herein may, however, be embodied in many different forms and should not be construed as limited to the example embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the concepts to those skilled in the art. Like numbers refer to like, but not necessarily the same or identical elements throughout.

[0024] Throughout this disclosure, various aspects are presented in a range format. It should be understood that the description in range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the disclosure. Accordingly, the description of a range should be considered to have specifically disclosed all the possible sub-ranges as well as individual numerical values within that range. For example, description of a range such as from 1 to 6 should be considered to have specifically disclosed sub-ranges suchas from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as individual numbers within that range, for example, 1, 2, 3, 4, 5, and 6. This applies regardless of the breadth of the range.

[0025] As used herein, the term “about” with reference to dimensions refers to the dimension plus or minus 10%.

[0026] Articles of cookware having non-stick coatings may be different types of cookware that are used for cooking food with little-to-no adhesion of the food to the cookware. Accordingly to the present disclosure, an article of cookware may include a non-stick coating formed from aluminum magnesium boride ( AlMgB 14), sometimes referred to as “BAM.”

[0027] Aluminum magnesium boride is a ceramic alloy having the empirical formulaAlMgB 14. This ceramic alloy is a metal boride characterized by icosahedra-shaped boron lattices joined to one another by additional boron atoms in a way that creates voids suitable for metal atoms to be incorporated within. These voids are filled with either aluminum or magnesium.However, the average number of metal atoms disposed within the voids is less than one resulting in a chemical composition that is non- stoichiometric, sometimes being described asAlo.75Bo.75B 14, Alo.75Mgo.7sB 14, or another non-stoichiometric, fractional index. Thus, although BAM is sometimes described herein as AlMgB 14, the decision to recite this chemical formula to the exclusion of any non-stoichiometric formula is in the interest of brevity only and is not intended to be limiting to any particular ratio of aluminum, magnesium, and boron atoms.Where “BAM” or the formula AlMgB 14 is used herein, it is to be understood that various non- stoichiometric, fractional indexes are contemplated as well.

[0028] BAM has exceptional durability, hardness, wear resistance, low coefficient of friction, and high thermal stability. BAM has therefore found usage in various mechanical andmachining industries, such as for wear resistance and friction reduction of gears, pistons, pumps and pump components, blades, and other cutting tools. These uses typically involve high cycle, high throughput industries, such as repetitious cutting on assembly lines or in engines and motors. However, these various uses involve coating BAM onto tool steel rather than stainless- steel or aluminum. The “mismatch” of coefficients of thermal expansion, described in more detail below, is not a concern when coating BAM onto tool steel, so the various challenges in using BAM on aluminum or stainless- steel had not yet been overcome.

[0029] It has been unexpectedly discovered that coating an article of cookware, such as a pot or pan or other cookware, with one or more layers of BAM results in a non-stick coating that has a coefficient of friction 80% lower than PTFE-based coatings, a hardness value over 45,000% greater than PTFE-based coatings, and thermal stability at temperatures over 380% greater than PTFE-based coatings (260°C for PTFE-based coatings before potentially harmful fumes versus a degradation temperature of l,260°C for B AM-based coatings). Furthermore, the dramatically improved hardness enables the use of metal cooking utensils that are traditionally discouraged for use with PTFE-based coatings. For example, Figures 1 A and IB depict a conventional pan 100 with a PTFE-coated interior, including a body portion 102 and one or more fasteners 104 that secure a handle 106 to the body portion 102, that has been damaged by metal utensils, as illustrated by abraded portion 108, and by normal wear and tear from use on a gas range, as illustrated by abraded portion 110.

[0030] The one or more layers of BAM may have any suitable thickness, provided the desired adhesion to the article of cookware, or “substrate,” is achieved, such as a thickness of from about 0.1 microns to about 50 microns, from about 1 micron to about 24 microns, from about 0.1 microns to about 4 microns, from about 0.5 microns to about 4 microns, from about 1 microns toabout 4 microns, from about 2 microns to about 4 microns, from about 3 microns to about 4, from about 0.1 microns to about 5 microns, from about 0.5 microns to about 5 microns, from about 1 microns to about 5 microns, from about 2 microns to about 5 microns, from about 3 microns to about 5, from about 4 microns to about 5 microns, from about 0.1 microns to about 6 microns, from about 0.5 microns to about 6 microns, from about 1 microns to about 6 microns, from about 2 microns to about 6 microns, from about 3 microns to about 6, from about 4 microns to about 6 microns, from about 5 microns to about 6 microns, from about 0.1 microns to about 7 microns, from about 0.5 microns to about 7 microns, from about 1 microns to about 7 microns, from about 2 microns to about 7 microns, from about 3 microns to about 7, from about 4 microns to about 7 microns, from about 5 microns to about 7 microns, from about 6 microns to about 7 microns, from about 0.1 microns to about 8 microns, from about 0.5 microns to about 8 microns, from about 1 microns to about 8 microns, from about 2 microns to about 8 microns, from about 3 microns to about 8, from about 4 microns to about 8 microns, from about 5 microns to about 8 microns, from about 6 microns to about 8 microns, from about 7 microns to about 8 microns, from about 0.1 microns to about 9 microns, from about 0.5 microns to about 9 microns, from about 1 microns to about 9 microns, from about 2 microns to about 9 microns, from about 3 microns to about 9, from about 4 microns to about 9 microns, from about 5 microns to about 9 microns, from about 6 microns to about 9 microns, from about 7 microns to about 9 microns, from about 8 microns to about 9 microns, from about 0.1 microns to about 10 microns, from about 0.5 microns to about 10 microns, from about 1 microns to about 10 microns, from about 2 microns to about 10 microns, from about 3 microns to about 10 microns, from about 4 microns to about 10 microns, from about 5 microns to about 10 microns, from about 6 microns to about 10 microns, from about 7 microns to about 10 microns, from about 8 microns to about 10 microns,from about 9 microns to about 10 microns, from about 0. 1 microns to about 11 microns, from about 0.5 microns to about 11 microns, from about 1 microns to about 11 microns, from about 2 microns to about 11 microns, from about 3 microns to about 11 microns, from about 4 microns to about 11 microns, from about 5 microns to about 11 microns, from about 6 microns to about 11 microns, from about 7 microns to about 11 microns, from about 8 microns to about 11 microns, from about 9 microns to about 11 microns, from about 10 microns to about 11 microns, from about 0.1 microns to about 12 microns, from about 0.5 microns to about 12 microns, from about 1 microns to about 12 microns, from about 2 microns to about 12 microns, from about 3 microns to about 12 microns, from about 4 microns to about 12 microns, from about 5 microns to about 12 microns, from about 6 microns to about 12 microns, from about 7 microns to about 12 microns, from about 8 microns to about 12 microns, from about 9 microns to about 12 microns, from about 10 microns to about 12 microns, from about 11 microns to about 12 microns. For example, in one embodiment, the layer of BAM has a thickness of about 4 microns. The thickness of the BAM layer may be 0.1 microns, 0.2 microns, 0.3 microns, 0.4 microns, 0.5 microns, 0.6 microns, 0.7 microns, 0.8 microns, 0.9 microns, 1 micron, 1.1 microns, 1.2 microns, 1.3 microns, 1.4 microns, 1.5 microns, 1.6 microns, 1.7 microns, 1.8 microns, 1.9 microns, 2 microns, 2.1 microns, 2.2 microns, 2.3 microns, 2.4 microns, 2.5 microns, 2.6 microns, 2.7 microns, 2.8 microns, 2.9 microns, 3 microns, 3.1 microns, 3.2 microns, 3.3 microns, 3.4 microns, 3.5 microns, 3.6 microns, 3.7 microns, 3.8 microns, 3.9 microns, 4 microns, 4.1 microns, 4.2 microns, 4.3 microns, 4.4 microns, 4.5 microns, 4.6 microns, 4.7 microns, 4.8 microns, 4.9 microns, 5 microns, 5.1 microns, 5.2 microns, 5.3 microns, 5.4 microns, 5.5 microns, 5.6 microns, 5.7 microns, 5.8 microns, 5.9 microns, 6 microns, 6.1 microns, 6.2 microns, 6.3 microns, 6.4 microns, 6.5 microns, 6.6 microns, 6.7 microns, 6.8 microns, 6.9microns 7 microns, 7.1 microns, 7.2 microns, 7.3 microns, 7.4 microns, 7.5 microns, 7.6 microns, 7.7 microns, 7.8 microns, 7.9 microns, 8 microns, 8.1 microns, 8.2 microns, 8.3 microns, 8.4 microns, 8.5 microns, 8.6 microns, 8.7 microns, 8.8 microns, 8.9 microns, 9 microns, 9.1 microns, 9.2 microns, 9.3 microns, 9.4 microns, 9.5 microns, 9.6 microns, 9.7 microns, 9.8 microns, 9.9 microns, 10 microns, 11 microns, 12 microns, 13 microns, 14 microns, 15 microns, 16 microns, 17 microns, 18 microns, 19 microns, 20 microns, 21 microns, 22 microns, 23 microns, 24 microns, 25 microns, 30 microns, 35 microns, 40 microns, 45 microns, 50 microns, or any integer or non-integers therebetween. The thickness of the BAM layer may be at least 1 micron, at least 2 microns, at least 3 microns, at least 4 microns, or at least 5 microns. The thickness of the BAM layer may be 0.1 or more microns, 0.5 or more microns, 1 or more microns, 2 or more microns, 3 or more microns, 4 or more microns, or 5 or more microns. The thickness of the BAM layer may be less than 4 microns, less than 5 microns, less than 6 microns, less than 7 microns, less than 8 microns, less than 9 microns, less than 10 microns, less than 11 microns, less than 12 microns, less than 13 microns, less than 14 microns, less than 15 microns, less than 16 microns, less than 17 microns, less than 18 microns, less than 19 microns, less than 20 microns, less than 21 microns, less than 22 microns, less than 23 microns, less than 24 microns, less than 25 microns, less than 30 microns, less than 35 microns, less than 40 microns, less than 45 microns, less than 50 microns.

[0031] BAM is typically formed having an amorphous atomic structure or a crystalline atomic structure. Although the one or more layers of BAM may retain the advantageous non-stick properties described herein at greater thicknesses, the structure of BAM may experience one or more different grain boundaries as the BAM layer(s) thickness increases due to the propagation of defects or impurities. Thus, B AM-based coating layers having thicknesses of greater thanaround 12 microns may benefit from the addition of one or more stabilizers, dopants, surfactants, or the like, depending on whether the changes to the material properties that accompany these greater thicknesses and grain boundary formation, if any, are desirable. Thicker BAM-based coating layers may also be achieved by modified process parameters such as various temperatures or pressures that may influence the surface activity during layer growth and may help in stabilizing thicker BAM-based coating layers.

[0032] Table 1 includes coefficients of friction for various materials, including polyether ether ketone (PEEK), a thermoplastic substance with high thermal stability that is sometimes applied to articles of cookware; diamond-like carbon (DLC), commonly used in tooling components such as drill bits and dies due to its favorable friction-reducing properties; and ice.Table 1: Coefficient of Friction for Various Materials

[0033] As displayed in Table 1, BAM-based coating layers have a coefficient friction that is60% lower than PTFE, which had previously been considered among the lowest coefficients of friction, especially for articles of cookware.

[0034] Table 2 includes hardness values in Vickers for various materials.Table 2: Hardness Values for Various Materials

[0035] As displayed in Table 2, BAM-based coating layers are dramatically harder than not only PTFE-based coatings, but harder than even uncoated stainless-steel.

[0036] As used herein, “article of cookware” refers to any piece of cookware designed to contact food and either transmit heat from a heat source to food for the purposes of cooking the food, or else withstand heat being used to cook the food even if in another article of cookware. For example, the article of cookware may be a pan of any suitable size or shape. The article of cookware may be a pot of any suitable size or shape. The article of cookware may be a reservoir for a kitchen appliance, such as an insert for a rice cooker, an insert for a pressure cooker, an insert for an air fryer such as an air fryer basket, or the like. The article of cookware may be an accessory for or a component of a kitchen appliance, such as non-stick trays or racks, grates, griddles, or the like. The article of cookware may be a kitchen appliance rack, such as the “wire” rack in an oven, toaster oven, or roaster. The article of cookware may be a cooling rack. The article of cookware can include one or more blades for a blender or a food processer. In some embodiments, the article of cookware may be a cooking utensil, such as a stainless- steel spatula or cooking tongs. The article of cookware can include any article of cookware that benefits from non-stick properties, benefits from high thermal stability, and / or benefits from high strength coatings provided by the BAM-based non-stick coatings described herein.

[0037] Figures 2A and 2B depict a pan 200 with a B AM-based non-stick coating 202, which may be formed from one or more BAM-based layers, according to embodiments of the present disclosure. The pan 200 includes a body portion 204, which can be formed from stainless-steel, and one or more fasteners 206 that secure a handle 208 to the body portion 204. According to the present disclosure, the BAM-based coating 202 can be disposed on an interior surface 210 of the pan body portion 204, including a substantially flat cooking surface 212 and a surface of curved sidewall 214 surrounding the cooking surface 212. In additional or alternative embodiments, a BAM based non-stick coating layer can also be disposed on an exterior surface of the pan 216, though this exterior surface can be generally free of the BAM based non-stick coating layer. The pan 200 is depicted during the cooking of an egg 218 in Figure 2A and after cooking the egg 218 in Figure 2B. Generally, as illustrated, substantially no food residue, or particles, is stuck to the cooking surface 212 of the pan 200. According to embodiments of the present disclosure, the pan may take the form of a conventional pan for cooking, such as a saucepan, frying pan, skillet, or the like. These pans generally have a flat cooking surface and sidewalls for keeping food in the pan. The sidewalls may be curved, such as in a frying pan, or the sidewalls may be vertical / straight, such as in a saucepan. The sidewalls may be straight but at an angle, such as in a skillet. Any suitable pan that would benefit from non-stick properties may be used provided the desired adhesion with the BAM-based coating is enabled.

[0038] In some embodiments, the article of cookware includes one or more layers, each of the one or more layers including stainless-steel or stainless-steel alloy, aluminum or aluminum alloy, cast iron, or anodized aluminum. Articles of cookware such as pots and pans are commonly formed from, for example, stainless- steel because stainless- steel cookware is durable, albeit heavy. Untreated stainless-steel cookware surfaces have poor non-stick properties, so stainless-steel cookware may need to be treated, either during manufacturing or by the chef, to prevent sticking of foods during cooking. Aluminum pots and pans trade some durability for a lighterweight article of cookware, but also have poor non-stick properties. Anodizing the aluminum can improves durability compared to non-anodized aluminum, but anodized aluminum articles of cookware remain several times stickier than, for example, PTFE-coated surfaces. Thus, the articles of cookware described herein may include one or more BAM-based non-stick coating layers on the upper-most facing material layer, which may be stainless-steel or stainless- steel alloy, aluminum or aluminum alloy, anodized aluminum, or another material so that the pan may take advantage of the inherent properties of these various substances (durable stainless- steel, light-weight aluminum, etc.) while gaining superior non-stick properties via the BAM-based coating.

[0039] In some embodiments, the article of cookware includes one or more layers of stainless- steel or stainless- steel alloy. Stainless-steel alloys used in cookware vary in the presence and / or amount of iron, carbon, chromium, nickel, manganese, molybdenum, vanadium, tungsten, silicon, sulfur, or phosphorous, and vary in the way the steel is prepared, such as in an open- hearth furnace, in an electric arc furnace, in a basic oxygen furnace, using cold working, using hot working, using quenching and tempering, etc. Stainless-steel alloys used in cookware are commonly graded by SAE International and are sometimes referred to in the industry with the prefix “SAE-” followed by numbers that refer to the series of steel alloy. These alloy series are also sometimes referred to by simply their SAE number, without the “SAE-” prefix.

[0040] In some embodiments, the one or more layers of stainless-steel or stainless-steel alloy may be SAE 200 stainless-steel, SAE 304 stainless-steel, SAE 305 stainless-steel, SAE 316 stainless- steel, SAE 430 stainless- steel, SAE 440 stainless- steel, or another suitable stainless-steel. However, minor variations in the stainless-steel that result in a different series are also contemplated but have been omitted in the interest of brevity only. For example, SAE 303 stainless- steel is the same as SAE 304 stainless-steel but with the addition of sulfur and phosphorous.

[0041] In some embodiments, the article of cookware includes one or more layers of aluminum or aluminum alloy. Aluminum alloys vary in their presence and / or amount of manganese, copper, silicon, magnesium, or zinc and the method of manufacturing or processing. Aluminum alloys are graded by The Aluminum Association and are referred to in the industry by a fourdigit system, sometimes with the “AA” prefix.

[0042] In some embodiments, the one or more layers of aluminum or aluminum alloy may be 1100 aluminum, 3003 aluminum, 5052 aluminum, 6061 aluminum, hard-anodized aluminum, or another suitable aluminum. However, minor variations in the aluminum that result in a different series are also contemplated but have been omitted in the interest of brevity only. For example, 3004 aluminum is similar to 3003 aluminum but includes magnesium.

[0043] In some embodiments, the article of cookware includes multiple material layers, also referred to as a “ply.” As used herein, a “material layer” refers to a metal or metal alloy layer that forms the primary structural material for the article of cookware. In other words, the one or more BAM-based coating layers, adhesion layer, and / or surface energy-improving material layer described herein are not “material layers.” In some embodiments, the article of cookware is two- ply, i.e., includes two material layers. In some embodiments, the article of cookware is three- ply, i.e., includes three material layers. In some embodiments, the article of cookware is four- ply, i.e., includes four material layers. In some embodiments, the article of cookware if five-ply, i.e., includes five material layers. The material layers may include stainless-steel or stainless-steel alloy, aluminum or aluminum alloy, copper or copper alloy, or the like. Tn some embodiments, all of the material layers in the article of cookware are the same or similar, such as three layers of stainless-steel alloy or three different stainless-steel alloys. In some embodiments, the material layers in the article of cookware vary in their material, such as a five- ply cookware comprising stainless-steel outer layers and three inner aluminum layers. Any suitable combination and quantity of material layers is contemplated.

[0044] In some embodiments, the article of cookware further includes an adhesion layer disposed between the article of cookware and the one or more BAM-based non-stick coating layers. BAM-based coating layers have coefficients of thermal expansion at around 9xl0'6K’1, while stainless-steel articles of cookware have a coefficient of thermal expansion (depending on the class and crystalline structure) at between about 9.9xl0'6K"1to about 17.3 xlO'6K'1and aluminum articles of cookware have a coefficient of thermal expansion of between about 21 xlO’6K’1to about 24xl0'6K'1. Despite this “mismatch” in the coefficients of thermal expansion, it has been unexpectedly discovered that adding an adhesion layer having an intermediate coefficient of thermal expansion may prevent cracking and delamination of the BAM-based nonstick coating layer.

[0045] Figure 3 depicts a schematic cross-section of a pan 300 having a substrate 302, adhesion layer 304, and a BAM-based coating 306 according to embodiments of the present disclosure. The BAM-based coating 306 may be formed from one or more BAM-based coating layers. The substrate 302 may be a single material, such as stainless-steel or stainless-steel alloy, or it may include multiple layers of material, as shown in Figure 4. Figure 4 depicts a schematic cross-section of a pan 400 having a two layers 402 of a first material, such as stainless-steel, surrounding two layers 404 of a second material, such as aluminum. An adhesion layer 406 isdeposited on the top layer 402 of the first material and a BAM-based coating 408, which may be formed from one or more BAM-based coating layers, is deposited on the adhesion layer 406 according to embodiments of the present disclosure. Thus, Figure 4 depicts a four-ply pan. However, more or fewer layers of the same or other materials may be included, as described herein.[00461 In some embodiments, the adhesion layer 406 includes titanium, chromium, or alloys thereof. Other materials may be suitable as an adhesion layer but may have unfavorable health consequences, such as antimony or antimony alloys, but these materials may nevertheless be used as an adhesion layer because the BAM-based non-stick coating layer(s) is incredibly durable and should prevent contact of the adhesion layer with any food. Other materials may be suitable as an adhesion layer but may prove prohibitively expensive, such as platinum, ruthenium, or alloys thereof, but reductions in the price of these metals could make them viable.

[0047] In some embodiments, the adhesion layer 406 is present at a thickness of from about 0.5 micron to about 5 microns. The thickness of the adhesion layer may be tuned depending on the base material in the article of cookware, depending on the intended use of the coated article of cookware, and depending on the thickness of the BAM-based non-stick coating layer(s). For example, some stainless- steel articles of cookware have coefficients of thermal expansion that differs from the one or more BAM-based coating layers by only a small amount; only a thin adhesion layer (if any) would be necessary to bridge the gap between these coefficients of thermal expansion. In contrast, aluminum articles of cookware have a larger mismatch in coefficient of thermal expansion as compared to the one or more BAM-based coating layers, so a thicker adhesion layer may be necessary.

[0048] In some embodiments, the non-stick coating layer further comprises an additive. Exemplary additives include silicon, phosphorus, titanium alloys such as titanium diboride or titanium carbide, nitrides such as aluminum nitride or boron nitride, and others. For example, in some embodiments, the incorporation of TiC may reduce hardness, which may represent an acceptable trade-off for a corresponding improvement in other properties, such as the coefficient of thermal expansion. As described above, BAM-based coating layers are over 45,000% harder than PTFE-based coatings, but the mismatch in coefficient of thermal expansion may reduce the coating’s longevity over multiple thermal cycles. Thus, the incorporation of additives such as TiC may reduce hardness from pure BAM-based coating layers while still representing an improvement over PTFE-based coatings, thus improving overall coating longevity.

[0049] In some embodiments, the article of cookware further includes a surface energy improvement treatment on top of the one or more BAM-based non-stick coating layers. The surface energy improvement treatment may take the form of an additional material layer, such as a functionalized silane layer, a polymer-based layer, a coating comprising a blend of AlMgB 14 and a polymer, or the like. For example, the functionalized silane layer may include octyltrichlorosilane, hexyltrichlorosilane, decyltrichlorosilane, dodecyltrichlorosilane, methyltrichlorosilane, phenyltrichlorosilane, vinyltrichlorosilane, or the like. The incorporation of a functionalized silane increases the surface energy of the surface of the one or more BAM- based coating layers on the article of cookware. The surface energy improvement treatment may take the form of a process, such as acid etching, laser irradiation, plasma treatment, laser ablative patterning, thermal annealing, or the like. The incorporation of a surface energy improvement treatment improves the surface energy and may enhance the non-stick properties of the one or more BAM-based coating layers.

[0050] Also described herein are methods of making articles of cookware having a non-stick coating. In some embodiments, the methods include providing an uncoated article of cookware and coating the article of cookware with one or more layers of aluminum magnesium boride (AlMgBi4).

[0051] In some embodiments, coating the article of cookware includes physical vapor deposition (PVD), sputter coating, arc sputtering, or laser powder deposition (LDP).Conventional PTFE-based non-stick coatings are applied to cookware using a spray-on coating, a method which cannot easily be adapted to BAM-based coatings. Instead, PVD, sputter coating, arc sputtering, and LDP involve generating a vacuum and vaporizing the coating material, which includes BAM in the present disclosure, and directing the vaporized material to the surface to be coated.

[0052] In some embodiments, before coating the article of cookware with the BAM-based nonstick coating layer(s), the surface of the article of cookware intended to be coated is treated. This surface treatment may include acid etching, laser irradiation, plasma treatment, laser ablative patterning, thermal annealing, or media blasting of the surface. This treatment may enhance the mechanical bonding of the article of cookware which may improve the PVD, sputtering, arc sputtering, or LPD process used to deposit the one or more BAM-based coating layers. For example, a 20% solution of nitric acid solution in deionized (DI) water may be used to lightly etch the surface of stainless-steel articles of cookware in advance of coating the article of cookware with the non-stick layers. A 30% solution of sulfuric acid sodium dichromate in DI water may be used to lightly etch the surface of aluminum articles of cookware in advance of coating the article of cookware with the non-stick layers. Other acids may be used to etch the surface of the article of cookware, such as various concentrations of nitric acid, hydrochloricacid, sulfuric acid, ferric chloride, or others. The decision to recite a specific acid and concentration herein is in the interest of brevity only and is not intended to limit the scope of the disclosure.

[0053] In some embodiments, the method includes coating the article of cookware with an adhesion layer before coating the article of cookware with the one or more BAM-based coating layers. For example, a layer of titanium or a layer of chromium may be deposited, such as by PVD, sputtering, arc sputtering, or LPD. As described previously, the coefficients of thermal expansion of the one or more BAM-based coating layers and of the article of cookware itself may differ such that an adhesion layer for bridging the gap between the coefficients of thermal expansion may advantageously improve layer adhesion and longevity.

[0054] In some embodiments, the method includes treating the non-stick layer with a surface energy improvement treatment. For example, treating the non-stick layer may include depositing a functionalized silane layer, depositing a polymer-based layer, depositing a coating including a blend of AlMgB 14 and a polymer, acid etching, laser irradiation, plasma treatment, laser ablative patterning, thermal annealing, or the like.

[0055] EXAMPLES

[0056] Example 1 : Producing BAM -coated pans

[0057] Five articles of cookware having BAM-based non-stick coatings were produced as described herein. The first three articles of cookware was a tri-ply stainless-steel pan having an SAE 304 stainless-steel upper layer, an AL 3003 aluminum alloy interior layer, and 460SS stainless- steel lower layer. The second article of cookware was an aluminum pan formed from an AL 3003 aluminum alloy. The third article of cookware was an anodized aluminum pan formed from an AL 3003 aluminum alloy with a 25-micron anodized coating on the uppersurface. As used herein, the “upper” layer or surface refers to the surface exposed to food in conventional use, while the “lower” layer refers to the surface in direct contact with the heat source in conventional use.

[0058] The stainless-steel pans were etched with a 20% nitric acid solution to provide improved mechanical adhesion.

[0059] Each of the aluminum and anodized aluminum pans were next coated with the AlMgBu layer without an adhesion layer.

[0060] One of the three stainless-steel pans was coated with the AlMgBu layer without the addition of an adhesion layer. One of the three stainless-steel pans was coated with a chromium adhesion layer before coating with the AlMgBu layer. The final stainless-steel pan was coated with a titanium adhesion layer before coating with the AlMgB layer. The titanium was sputter coated onto each pan with a target adhesion layer thickness of 1 micron.

[0061] The AlMgBu was sputter coated using a 99% pure AlMgB 14 sputter target, part number AL-MGBO-02-ST available commercially from American Elements®, Los Angeles, California, USA. The sputtering tool was an AJA International ATC 1800-F, available commercially from AJA International, Inc., Hingham, Massachusetts, USA. The sputter power was 225 watts, the substrate temperature was 100°C, the argon flow rate was 0.06 L / min, and the vacuum was set to 3.0’3Torr.

[0062] Example 2: Contact Angle Measurements

[0063] A BAM-based coated pan was analyzed for the water contact angle and compared to four commercial PTFE-based pans, labeled as PTFE - 1, PTFE - 2, PTFE - 3, and PTFE - 4.The contact angle is a measurement of the wettability of a surface, with a low contact anglecorresponding to a high surface energy and to superior non-stick properties. The results of the analysis is displayed in Table 3. Table 3: Water Contact Angle Measurements[00641 As shown in Table 4, the contact angle of the BAM-based coating is comparable to the PTFE-based coatings. Furthermore, the contact angle for non-stick pans is generally 90° or greater, so the BAM-based coated pan has wettability suitable for use as a non-stick pan.

[0065] Though the disclosed examples include particular arrangements of a number of parts, components, features, and aspects, the disclosure is not limited to only those examples or arrangements shown. Any one or more of the parts, components, features, and aspects of the disclosure may be employed alone or in other arrangements of any two or more of the same.

[0066] Although certain product features, functions, components, and parts have been described herein in accordance with the teachings of the present disclosure, the scope of coverage of this patent is not limited thereto. On the contrary, this patent covers all embodiments of the teachings of the disclosure that fairly fall within the scope of permissible equivalents.

[0067] Unless otherwise noted, the terms used herein are to be understood according to conventional usage by those of ordinary skill in the relevant art. In addition to the definitions ofterms provided below, it is to be understood that as used in the specification and in the claims, “a” or “an” may mean one or more, depending upon the context in which it is used.

[0068] Throughout this application, the term “include,” “include(s)” or “including” means “including but not limited to.” Note that certain embodiments may be described relating to a single element, but the corresponding description should be read to include embodiments of two or more elements. Different features, variations, and multiple different embodiments are shown and described herein with various details. What has been described in this application at times in terms of specific embodiments is done for illustrative purposes only and without the intent to limit or suggest that what has been conceived is only one particular embodiment or specific embodiments. It is to be understood that this disclosure is not limited to any single specific embodiments or enumerated variations. Many modifications, variations and other embodiments will come to mind of those skilled in the ait, and which are intended to be and are in fact covered by this disclosure. It is indeed intended that the scope of this disclosure should be determined by a proper legal interpretation and construction of the disclosure, including equivalents, as understood by those of skill in the art relying upon the complete disclosure present at the time of filing.

[0069] Conditional language, such as, among others, “can,” “could,” “might,” or “may,” unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain implementations could include, while other implementations do not include, certain features, elements, and / or operations. Thus, such conditional language generally is not intended to imply that features, elements, and / or operations are in any way required for one or more implementations or that one or more implementations necessarilyinclude logic for deciding, with or without user input or prompting, whether these features, elements, and / or operations are included or are to be performed in any particular implementation.

[0070] What has been described herein in the present specification and drawings includes examples of systems, apparatuses, methods, devices, and / or techniques. It is, of course, not possible to describe every conceivable combination of components and / or methods for purposes of describing the various elements of the disclosure, but it may be recognized that many further combinations and permutations of the disclosed elements are possible. Accordingly, it may be apparent that various modifications may be made to the disclosure without departing from the scope thereof. In addition, or as an alternative, other embodiments of the disclosure may be apparent from consideration of the specification and annexed drawings, and practice of the disclosure as presented herein. It is intended that the examples put forth in the specification and annexed drawings be considered, in all respects, as illustrative and not limiting. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation. Various features and characteristics of embodiments of the present disclosure as discussed herein may be selectively interchanged and applied to other illustrated and non-illustrated embodiments of the disclosure, and numerous variations, modifications, and additions further can be made thereto without departing from the spirit and scope of the present invention as set forth in the appended claims.

[0071] Further aspects of the invention are provided by the subject matter of the following clauses.

[0072] Clause 1: An article of cookware comprising a non-stick coating, wherein the non-stick coating comprises aluminum magnesium boride (AlMgBu).

[0073] Clause 2: The article of cookware of clause 1 , wherein the article of cookware comprises one or more layers, each of the one or more layers comprising stainless- steel or stainless- steel alloy, aluminum or aluminum alloy, cast iron, or anodized aluminum.

[0074] Clause 3: The article of cookware of clauses 1 or 2, wherein the non-stick coating has a thickness of from about 0.1 microns to about 50 microns.

[0075] Clause 4: The article of cookware of any one of clauses 1 to 3, wherein the non-stick coating has a thickness of from about 0.5 microns to about 10 microns.

[0076] Clause 5: The article of cookware of any one of clauses 1 to 4, further comprising an adhesion layer between the article of cookware and the non-stick coating.

[0077] Clause 6: The article of cookware of clause 5, wherein the adhesion layer comprises titanium or chromium.

[0078] Clause 7: The article of cookware of clause 5, wherein the adhesion layer has a thickness of from about 1 micron to about 5 microns.

[0079] Clause 8: The article of cookware of any one of clauses 1 to 7, wherein the non-stick coating further comprises an additive.

[0080] Clause 9: The article of cookware of clause 8, wherein the additive comprises silicon, phosphorus, titanium alloys such as titanium diboride or titanium carbide, or nitrides such as aluminum nitride or boron nitride.

[0081] Clause 10: The article of cookware of any one of clauses 1 to 9, further comprising a surface energy improvement treatment on top of the non-stick coating, wherein the surface energy improvement treatment comprises a functionalized silane layer, a polymer-based layer, a blend of AlMgB 14 and a polymer coating, acid etching, laser irradiation, plasma treatment, laser ablative patterning, thermal annealing, or the like.

[0082] Clause 11 : The article of cookware of clause 10, wherein the functionalized silane layer comprises octyltrichlorosilane, hexyltrichlorosilane, decyltrichlorosilane, dodecyltrichlorosilane, methyltrichlorosilane, phenyltrichlorosilane, vinyltrichlorosilane, or the like.

[0083] Clause 12; The article of cookware of any one of clauses 1 to 11, wherein the article of cookware is a cooking pot, a pan, a non-stick reservoir for a kitchen appliance, a cooling rack, a kitchen appliance rack, or the like.

[0084] Clause 13: A method of making an article of cookware having a non-stick coating, the method comprising: providing an uncoated article of cookware; and coating the article of cookware with one or more layers of aluminum magnesium boride (AlMgBu).

[0085] Clause 14: The method of clause 13, wherein coating the article of cookware comprises physical vapor deposition (PVD), sputter coating, arc sputtering, or laser powder deposition (LPD).

[0086] Clause 15: The method of clause 13 or 14, further comprising treating a surface of the article of cookware before coating the article of cookware with AlMgB14.

[0087] Clause 16: The method of clause 15, wherein treating the surface of the article of cookware comprises acid etching, laser irradiation, plasma treatment, laser ablative patterning, thermal annealing, or coating the surface with a functionalized silane layer.

[0088] Clause 17: The method of any one of clauses 13 to 16, further comprising coating the article of cookware with an adhesion layer before coating the article of cookware with AlMgBu.

[0089] Clause 18: The method of clause 17, wherein the adhesion layer comprises titanium or chromium.

[0090] Clause 19: The method of any one of clauses 13 to 18, further comprising treating the non-stick layer with a surface energy improvement treatment.

[0091] Clause 20: The method of clause 19, wherein treating the non-stick layer comprises depositing a functionalized silane layer, depositing a polymer-based layer, depositing a coating including a blend of AlMgBu and a polymer, acid etching, laser irradiation, plasma treatment, laser ablative patterning, thermal annealing, or the like.T1

Claims

CLAIMSWhat is claimed is:

1. An article of cookware comprising a non-stick coating, wherein the non-stick coating comprises aluminum magnesium boride (AlMgBu).

2. The article of cookware of claim 1, wherein the article of cookware comprises one or more layers, each of the one or more layers comprising stainless-steel or stainless-steel alloy, aluminum or aluminum alloy, cast iron, or anodized aluminum.

3. The article of cookware of claim 1 , wherein the non-stick coating has a thickness of from about 0.1 microns to about 50 microns.

4. The article of cookware of claim 1, wherein the non-stick coating has a thickness of from about 0.5 microns to about 10 microns.

5. The article of cookware of claim 1 , further comprising an adhesion layer between the article of cookware and the non-stick coating.

6. The article of cookware of claim 5, wherein the adhesion layer comprises titanium or chromium.

7. The article of cookware of claim 5, wherein the adhesion layer has a thickness of from about 1 micron to about 5 microns.

8. The article of cookware of claim 1, wherein the non-stick coating further comprises an additive.

9. The article of cookware of claim 8, wherein the additive comprises silicon, phosphorus, titanium alloys such as titanium diboride or titanium carbide, or nitrides such as aluminum nitride or boron nitride.

10. The article of cookware of claim 1, further comprising a surface energy improvement treatment on top of the non-stick coating, wherein the surface energy improvement treatment comprises a functionalized silane layer, a polymer-based layer, a blend of AlMgB 14 and a polymer coating, acid etching, laser irradiation, plasma treatment, laser ablative patterning, thermal annealing, or the like.

11. The article of cookware of claim 10, wherein the functionalized silane layer comprises octyltrichlorosilane, hexyltrichlorosilane, decyltrichlorosilane, dodecyltrichlorosilane, methyltrichlorosilane, phenyltrichlorosilane, vinyltrichlorosilane, or the like.

12. The article of cookware of claim 1, wherein the article of cookware is a cooking pot, a pan, a non-stick reservoir for a kitchen appliance, a cooling rack, a kitchen appliance rack, or the like.

13. A method of making an article of cookware having a non-stick coating, the method comprising: providing an uncoated article of cookware; and coating the article of cookware with one or more layers of aluminum magnesium boride (AlMgBu).

14. The method of claim 13, wherein coating the article of cookware comprises physical vapor deposition (PVD), sputter coating, arc sputtering, or laser powder deposition (LPD).

15. The method of claim 13, further comprising treating a surface of the article of cookware before coating the article of cookware with AlMgBu.

16. The method of claim 15, wherein treating the surface of the article of cookware comprises acid etching, laser irradiation, plasma treatment, laser ablative patterning, thermal annealing, or coating the surface with a functionalized silane layer.

17. The method of claim 13, further comprising coating the article of cookware with an adhesion layer before coating the article of cookware with AlMgBu.

18. The method of claim 17, wherein the adhesion layer comprises titanium or chromium.

19. The method of claim 13, further comprising treating the non-stick layer with a surface energy improvement treatment.

0. The method of claim 19, wherein treating the non-stick layer comprises depositing a functionalized silane layer, depositing a polymer-based layer, depositing a coating including a blend of AIMgBy and a polymer, acid etching, laser irradiation, plasma treatment, laser ablative patterning, thermal annealing, or the like.

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