JP2007525335A - Aluminum phosphate compounds, compositions, materials and related metal coatings - Google Patents

Abstract

A composite comprising a metal substrate, a substantially amorphous, substantially nonporous aluminophosphate film and a component therebetween, said component interacting with the oxide of the metal element of the substrate to bind phosphate groups Containing complex.
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Description

  The present invention relates to the development of new amorphous inorganic oxide materials, which are useful in many applications that can be used in powders, bulk, fibers as thin films or coatings as they are microstructurally dense. The present invention also provides for protection against wear and abrasion, corrosion and oxidation in temperature ranges and harsh environments, and to provide suitable high emissivity, non-wetting and non-stick surfaces. It relates to surface modification of metals and alloys by application of thin films.

  The US government has approved license numbers F49620-00-C-0022 and F49620-01-C-0014 from AFOSR (Air Force Science Research Agency) and DE-FG02-OlER83149 from the Ministry of Energy (Applied Thin Film, Inc. respectively). As well as specific rights to this invention.

There are many prior art patents relating to the synthesis of aluminum phosphate materials primarily for use as catalyst supports including crystalline and amorphous forms. The main synthesis method is a sol-gel method using a raw material containing various phosphorus sources including a generally available aluminum salt and various phosphoric acids, hydrogen hydrogen phosphate, phosphorous acid and the like. Many of these methods result in highly porous, crystalline forms and a slight heat stable amorphous composition (US Pat. No. 4,289,863, Hill et al., US Pat. Nos. 5,698,758 and 758). No. 5,552,361, both Rieser et al., US Pat. No. 6,022,513, Pecoraro et al., US Pat. No. 3,943,231, Wasel-Nielen et al., US Pat. No. 5,030,431, Glemza US Pat. No. 5,292,701, Glemza et al., US Pat. Nos. 5,496,529 and 5,707,442, both Fogel et al.). Two prior art patents teach the formation of amorphous aluminum phosphate compositions. However, the derived material is highly porous as required for catalyst applications. U.S. Patent No. 4,289, 863 Patent, also very lower temperatures poor composition Al to crystallize in teaches a novel process for the synthesis of AlPO ₄ composition of amorphous enriched in more thermally stable Al . U.S. Pat. No. 6,022,513 teaches a slightly modified method of producing an Al-rich composition that results in different forms of amorphous aluminophosphate materials with different microstructures. However, both methods of synthesis have a surface area ranging from 90 to 300 square meters / g and a micropore volume of at least 0, as shown in the Pecoraro patent (pores from 60 nm to 1000 nm (US Pat. No. 5,698,758)). Resulting in a highly porous material of 1 ccs / g.

  The many usefulness of such prior art amorphous materials is their use as thin films on metals and alloys, glass and ceramic substrates. To facilitate this utility, a combination of additional properties provides a stable, low cost precursor solution and environmentally friendly, cost effective and versatile coating that provides good adhesion to the substrate described above. This is advantageous because it involves a process. There is a growing need for coatings on metal and alloy substrates to perform protection and other surface related functions. Most prior art methods require either special pretreatment or additional layers, especially to improve adhesion to metal and alloy substrates. In the paint industry, the use of primers containing phosphating agents is well known. Conversion coatings are well known in the art as pretreatment techniques that provide corrosion protection and promote adhesion with paint. In this method, a metal or alloy surface is treated with an acid or other chemical containing phosphate or chromate that reacts with the metal component of the substrate to form a metal phosphate or chromate. However, these methods are toxic to the environment and do not provide adequate protection. Similar plummer layers have been used to apply adhesive coatings to metals and alloys. However, this increases costs and places additional constraints on finding what fits the material properties in a multilayer coating system. For corrosion protection and other purposes, there is an aspiration for the development of a one-step coating process that achieves both good tack and substantially non-porous amorphous inorganic layers.

The prior art teaches that phosphate is an excellent primer that improves adhesion to metal substrates. Some patents are based on using phosphate as a functional group for better adhesion to metal surfaces. See, for example, US Pat. No. 6,140,410. P-O - ^/ by M ²⁺ formation of ionic bonds in order to improve the adhesion of the polyurethane resin to the metal, and select the phosphate monomer, imparting phosphate reactive groups in the main chain of the final phosphorylation polyurethane resin To do. See, for example, US Pat. No. 6,221955. Also, the adhesion between the metal and the polymer material is enhanced by contacting the non-phosphate adhesion-promoting composition with the metal surface before bonding the polymer material to the metal surface. See U.S. Patent No. 6,554,948.

  There have been many studies on applying thin layers to steel surfaces by the sol-gel method. For example, to improve corrosion resistance, a stainless steel surface is coated with a zirconium dioxide layer. Borosilicate glass layers have also been studied.

However, systems that are difficult to process (high melting point oxides such as ZrO ₂ ) do not become high-density layers by the above technique, and borosilicate glass layers can only be applied in layers much thinner than 1 micron. Therefore, it was found that sufficient mechanical and chemical protection could not be ensured (sol-gel coating on metals, M. Guglielmi, Journal of sol-gel science and technology, 8,443-449 (1997); Sol-gel method for material coating, LF Francis, Materials and Manufacturing Processes 12,963-1015, 1997). It is desirable to use a heat resistant and stable amorphous high density coating to protect various substrates. The main advantage of amorphous coatings is that when a suitable process is developed, an air barrier seal can be applied on the substrate to prevent gas or liquid contact that could potentially corrode the substrate. Many methods have been developed to deposit a uniform crystalline coating substantially free of pores or cracks. The crystalline coating does not provide an air barrier that protects it from exposure to gases or liquids.

  Amorphous coatings based on silicon dioxide have been developed. Recent patents define a unique method of depositing such coatings (US Pat. No. 6,162,498). However, the coating is not durable under certain harsh conditions, is not thermally stable at high temperatures, or does not function well as a transparent coating on glass due to processing constraints. Also, high temperature stable glassy or glassy coatings have been developed. This involves first coating the substrate with a slurry of glass frit and then treating the coating material at a sufficiently high temperature to melt the glass frit to form a glassy coating. Glassy enamel coatings in many different compositions have existed for decades. However, they are usually thick, porous and deform at high temperatures. Although air barrier protection may be achieved in this manner, the need for high temperature processing to melt the glass frit may degrade the substrate, and once a low melting glass composition is selected, they are Because of the durability may be lost.

  U.S. Pat. No. 6,403,164 discloses a method of using organic-inorganic composite membranes and other applications for protection against corrosion. The deposited film is dense and pore free, but is not suitable for high temperature applications (300 ° C. and above) and is relatively soft due to the presence of organic materials in the film. Such a film is not resistant to abrasion or abrasion.

  Prior art coatings are derived from various methods and include amorphous aluminum phosphate on the metal. British Patent 1,451,145 discloses a method of forming a hydrated form coating of aluminum phosphate on a metal using chemical solution methods. The coating is not hard due to the low temperature cure method and the presence of water (hydrate form), is not sufficiently resistant to abrasion encountered in many applications, and provides sufficient oxidation or corrosion protection, Inorganic form and not microstructurally dense.

British Patent Nos. 1,322,722, 1,322,724 and 1,322,726, and “New low cure temperature, glassy, inorganic derived from soluble composites of aluminum and other metal phosphates” The document published under the title “Coating” (Chemistry and Industry, vol. 1, (1974) 457-459) discloses the use of a soluble polymer complex consisting of HC1 and an aluminum phosphate with a hydroxy-organic ligand. Although high density amorphous aluminum phosphate films have been reported to utilize this method, there are several disadvantages associated with their poor performance that cannot be implemented in commercial applications. First, the film contains residual chlorine (at least 1% by weight) that is undesirable for many metals and alloys. Secondly, as the film cures, toxic HC1 gas, an important environmental issue, is released (the complex contains 1 mole of HC1 for 1 mole of AlPO ₄ ). Third, the synthesis method is relatively complex, such as separating the crystalline form of the complex and then dissolving it in a suitable solvent, making it difficult to implement in practical applications.

  In order to form the precursors in the prior art described above, inert and / or vacuum treatment is required, and whether the prepared precursor solution has sufficient storage stability or whether the solution is environmental. It is not clear whether it will decompose upon exposure to (a potential concern for the presence of volatile organics (eg ethanol) present as a ligand). Also, no particular illustration is given regarding the deposition of a film on a metal substrate or the effect on them in an oxidation or corrosion test. Due to the highly acidic nature of the precursor solution, the metal or alloy substrate may be subjected to severe attack by chloride attack during film formation.

  Furthermore, because of the low curing temperature, the adhesion to the substrate may not be high enough to give a durable film. Curing temperatures in the range of 200 to 500 ° C. have been suggested, but in most cases curing temperatures of 200 ° C. or lower are used, specific examples of films cured at 500 ° C. are not shown, and fine There is no structural information. Furthermore, the coating was found to adhere to the molten aluminum. Aluminum phosphate has been found to be non-wetting due to its low surface energy, although it is chemically compatible with molten aluminum in a pure crystalline or amorphous form. Prior art coatings are not chemically durable due to poor adhesion (due to the presence of chlorine, poor film coverage, or poor high temperature properties), non-sticky or non-wetting properties It is believed that the surface energy is not low enough that application applicability cannot be utilized.

  In the prior art described above, it was further necessary to extend the amorphous properties of the material by adding silicon and boron. By adding these, after annealing the powder material at 1090 ° C. for 3 hours, there was a sufficient crystalline content (scaleite and cristobalite). As will be described later, in the present invention, various Al / P stoichiometric materials were found after heat treatment at higher temperature and longer time, with a large amount of amorphous content only in the presence of clinopite phase. . It is not uncommon for amorphous materials made using various techniques to have unique structures or network portions that can significantly change their atomic diffusion coefficient and high temperature properties. It appears that the network structure of the material derived under the above mentioned patent does not give a strong microstructure and may not be suitable for use, especially at high temperatures.

  Thus, the materials produced by prior art methods are not microstructurally dense or strong enough to provide the desired protection. Furthermore, none of the prior art methods provide an economical, stable, transparent, suitable process or precursor solution, and use various known techniques (eg, dip, spray, brush and flow). Cannot be applied. Furthermore, none of the processes associated with prior art methods provide the ability to provide good adhesion to a substrate, which is crucial for most applications. When materials are subjected to heat treatment or exposed to corrosive environments, prior art coatings are not durable under certain atmospheric conditions or in certain harsh industrial or use environments. Also, prior art inorganic coatings are not completely transparent for use on glass or other substrates where the aesthetic properties of the substrate (metallic appearance) need to be preserved.

  As a related technical consideration, high strength metals (eg, zirconium and zirconium alloys, titanium and titanium alloys, alloy steels, etc.) become brittle when exposed to hydrogen atoms. This brittleness is known to be related to the penetration of hydrogen atoms into the metal lattice and has been the subject of extensive research. Despite strenuous efforts to elucidate, and struggling with such hydrogen embrittlement, this phenomenon still remains, for example, heat transfer piping in nuclear power plants manufactured with zirconium alloys, It is a major cause of failure of ultrasonic aircraft segments made of titanium alloys and mechanical parts such as bolts and shafts made of alloy steel.

  In the past, efforts have been made to overcome this catastrophic phenomenon through the use of coatings as diffusion barriers that have largely failed due to the very high permeability of hydrogen through most coating materials. Although palladium coatings may theoretically be considered in terms of their superior properties and moderate surface hardness, commercially attractive methods of applying palladium films require high surface coverage. To do. However, such surface coverage often results in undesirable film properties. In many such processes, it has been found that palladium films are brittle and susceptible to cracks. In addition, the process is expensive and produces environmentally toxic byproducts.

  Metals placed in voltage system means that react with water are susceptible to corrosion and require protective coatings that protect against attack by water and / or oxygen. To this end, the prior art includes a very wide range of processes but has not yielded good results. Anodizing of aluminum (Eroxal method) is a very well-known method of forming a protective alumina film, but the process cannot produce an alumina film without pinholes, and the related electrolysis method is Limits its application and produces environmentally toxic substances.

  As is apparent from the above, the microstructurally dense form of amorphous aluminophosphate would be very useful for many applications. However, prior art materials will not adequately protect the substrate against them, for example, because they are corroded and oxidized at high temperatures. Porosity is not desired for use in fibers for applications that reinforce composites, or for optical applications. For photonic or laser applications, aluminum phosphate is desired as the glass host material. Erbium-doped phosphate glass has been developed as a fiber or for planar waveguide amplifiers, where high density materials are required for optical transmission without any loss due to scattering.

  In light of all the shortcomings of the prior art discussed above, the need for a stable, microstructurally dense form of chemically durable and thermally stable aluminophosphate for a wide range of applications. There is. Accordingly, it is an object of the present invention to provide amorphous aluminophosphate compounds, compositions and / or materials for protective, functional and multifunctional substrate coatings. Thus, high density, smooth, continuous, airtight or substantially capable of depositing on various substrates with good adhesion, simple and low cost with environmentally friendly process There is a need to develop a nonporous, transparent, durable glassy coating. Most current and new applications utilizing metal / alloy substrates require multifunctional coatings that can induce other properties along with corrosion protection. For example, antimicrobial coatings are required to limit the spread of bacteria and disease to metal substrates. It is desirable to develop coatings that provide both corrosion and antibacterial protection. Thus, a thermally stable and strong glassy coating material can be flexible to induce multifunctional properties and is practical for use in industrial and commercial applications Must be developed with an accompanying precursor system that is reasonable (ie, low cost, simple, and environmentally compatible).

  It will be appreciated by those skilled in the art that one or more aspects of the present invention may meet certain objectives, while one or more aspects of the present invention may meet certain other objectives. Each objective may not apply equally in all respects to all aspects of the invention. Thus, the following objects can be selectively grasped with respect to any one aspect of the present invention.

  A further object of the present invention is to develop a vitreous coating system (preferably transparent) that provides effective corrosion protection for a very wide variety of metal substrates, preferably in combination with abrasion resistance.

  According to the present invention, it has been found that this object can be achieved by depositing an aluminofate coating on the metal. Because of the inorganic network, the resulting coating is also abrasion resistant, which can be further enhanced by incorporating nanoscale particles. Nanoparticles include particle sizes in the range of about 1 nm to about 500 nm. Another effect of incorporating nano-sized particles is that such coatings remain transparent. Accordingly, the present invention provides a method for protecting a metal substrate from corrosion by forming an inorganic glassy oxide film.

  In accordance with the present invention, it has now been found that a specific precursor can be used to form a vitreous layer on a metal surface, and the layer can be less than about 10 microns in size. Surprisingly, it has also been found that such a layer can be converted into a high-density aluminum phosphate film (for example at a stainless steel or steel surface). Such a film is about 2, 3 nm to about 2, 3 microns thick, each preventing or drastically reducing oxygen ingress into the metal substrate and ensuring a good protection against corrosion even at high temperatures. Form a layer. In addition, such layers are abrasion resistant. Furthermore, such coatings are flexible, i.e., bending the surface does not cause cracks or other degradation in the layer.

  Another object of the present invention is to develop a stable, microstructurally dense form of aluminophosphate material for use in the applications described above. A further object of the invention is to develop a low cost, simple and versatile chemical solution based method for developing amorphous materials in the form of powders, coatings, fibers and bulk materials.

  Yet another object of the present invention is to prepare a suitable transparent precursor solution that provides a high quality high density coating of amorphous aluminophosphate. A further object is to develop a suitable precursor solution in which other additives can be added to the solution so that a novel amorphous aluminophosphate composition can be produced. The additive can be added in a chemical form such that the solution is clear, or the additive can be added in colloidal or powder form to provide a slurry-based solution. In any of the precursor forms used, the resulting cured material should be in the form of a nanocomposite (nanoparticles, nanocrystals or crystals embedded or encapsulated in an amorphous aluminophosphate matrix). And can be present as a uniformly dispersed dopant within the glass matrix. In any of these forms, the additive can induce specific functionality useful for many indications, either individually or in conjunction with an aluminophosphate matrix. Such “mixed” aluminophosphate compositions can be formed as a powder or coating or fiber, or as a bulk material. Other objects of the invention include inclusions in amorphous matrix materials to induce various functions including, but not limited to, optical, chemical, catalytic, physical, mechanical and electrical properties. Accompanied by developing a film of the compounds, compositions and / or materials of the present invention. Such inclusions can be produced in situ during the synthesis process and they may include compounds that combine metals, non-metals and any element. One such example involves the formation of carbon as a nano-sized inclusion to provide high emissivity, enhancing mechanical properties. High emissivity coatings that are durable at high temperatures are desirable for many applications where protection against heat is desired, or such coatings re-radiate incident heat flow rates in furnaces, ducts, boilers, heat exchangers, etc. This eliminates energy waste.

  The purpose of the present invention is to create nanocrystals (nanocomposite coatings) that enhance coating properties or induce or enhance chemical, physical, optical, electrical, mechanical and thermal properties. Regardless of the P / Al ratio and any further metals contained therein, the molecular structure is characterized by the O = P—O—Al—O—Al bond arrangement (organic or other capable of binding to P and Al A material having a ligand).

  It is an object of the present invention to provide a surface modification of a metal or alloy with a material coating that provides corrosion resistance or oxidation resistance and / or induces non-stickiness over temperature and environment, Its effectiveness in steel, aluminum alloys, nickel-based superalloys, Inconel and other steel alloys has been demonstrated.

  An object of the present invention is to provide materials for developing coatings of about 0.05 microns to about 10 microns (preferably about 100 nm, more preferably about 500 nm, most preferably about 1 micron); The coating is dense, continuous, smooth, uniform and transparent. The compounds, compositions and / or materials and / or related coatings of the present invention are hermetic, i.e., have no open pores or pathways for the ingress of liquids or gases and / or are microstructurally high. Density, i.e. substantially non-porous and / or pore volume approximately equal to zero. Yet another object of the present invention is to develop thin films in the range of about 50 nm to about 10 microns that are transparent or opaque as desired for any application. Yet another object of the present invention is that the substrate profile or characteristics need not be adjusted to accommodate the thickness of the film deposited for protection or other purposes of surface modification. It is possible to use these thin films for applications that require strict design tolerance maintenance. As thin films of about 1 micron or less, the film of the compounds, compositions and / or materials of the present invention is sufficiently effective and no substrate modification is required for most applications.

  It is an object of the present invention to provide a cured coating using a furnace or heating or infrared lamp or UV irradiation (preferably at 800 ° C., more preferably at 600 ° C., most preferably at 500 ° C.) UV irradiation with heat can cure the coating at 250 ° C. A related object of the present invention is to provide a curing method for good adhesion of the coating material.

  It is an object of the present invention to provide a coating deposited using a dip or spray or flow or brush painting method. A further object of the present invention is to develop a method that utilizes a stable precursor solution (which does not hydrolyze or degrade when exposed to the environment) and a transparent precursor solution, including dip, spray, flow and brush methods. A versatile deposition process would be possible.

  The object of the present invention is to provide a material that functions as a protective coating in a short time, but also functions as a protective coating in contact with high temperatures over a long period of time, that is, only stable oxides form directly beneath it. As can be achieved by low oxygen partial pressure at the metal / coating interface at an early stage, so as to enhance the protection of the substrate for a long time, promote the formation of a protective oxide scale under that condition . For example, stainless steel AUS304 forms a dense chromium-rich oxide over porous iron or manganese oxide. Although higher chrome steel is preferred for this reason, it should be noted that the material of the present invention remains oxidation resistant due to Cr-rich oxide scale, even with low Cr content steel. . This evidence was obtained with X-ray diffraction and elemental profiles across the scale. A similar phenomenon occurs in nickel-based superalloys where the alumina scale is preferentially formed in the early stages of oxidation. Differences in the order of oxidation rate are realized due to the presence of these coatings. This allows the use of low cost alloys to be selected for a particular application, and the alloy composition can have other properties such as fatigue resistance, thermal conductivity, thermal expansion, electrical properties, etc. Can be adjusted to promote (not oxidative).

  An object of the present invention is to provide thermal barrier coating (TBC) applications. The growth of alumina scale between the bond coat and the ceramic coating leads to premature failure of the TBC. The coating of the present invention can be deposited on a MCrAlY type bond coat, then TBC is deposited (preferably by electron beam PVD), thereby limiting the growth of alumina scale in service, It will prevent catastrophic failure of TBC due to crushing. Proof of principle has already been demonstrated with the deposition of the compounds, compositions and / or materials of the present invention on bond coats, showing that the increase in weight is reduced with oxidation above 1100 ° C.

  It is an object of the present invention to provide a material coating that is sufficiently smooth to provide a low friction surface (coefficient of friction of 0.1 or less measured with a coating on steel alloy). This allows the material to be used as a high temperature solid lubricant or as an abrasion resistant coating over a range of temperatures and environments. In this case, the compounds, compositions and / or materials of the present invention are multifunctional protective coatings (the nanocrystals in the material coating can be added to improve wear resistance or adjust thermal properties. ). Yet another object of the present invention is to reduce substrate surface roughness that is desired for many applications. The smoothness properties of the deposited compounds, compositions and / or material films of the present invention allow planarization of most substrates. This helps to enhance the non-wetting or non-tackiness of the surface, and also adds the benefit of low surface energy due to the stable oxide surface on the metal / alloy substrate, thereby reducing the friction surface Bring. A related object of the present invention is to provide protection against atmospheric corrosion of any metal / alloy due to the hermetic nature of the coating.

  It is an object of the present invention to provide protection of metal and alloy surfaces containing defects that cause "promoting corrosion". Moisture contact at these sites is high temperature oxidation, and after a while, surface micron-sized defects finally integrate at the surface, leading to "breakaway" oxidation, 100 microns wide The behavior that spreads to the above pit is brought about. The compounds, compositions and / or materials of the present invention cover these defects equally and eliminate accelerated corrosion. Because of this problem, metals and alloys are subjected to a complete surface treatment that can be reduced or eliminated with the use of such coatings, which results in labor and material costs and creates waste.

  It is an object of the present invention to provide a material coating on metals and alloys that can be used in many applications where moving parts are used due to non-stick properties. If there is debris that is moved back and forth during service, and sticks to the surface, the movement is affected and eventually leads to failure of the part. The compounds, compositions and / or materials of the present invention will be useful without allowing undesired debris sticking to these parts. Its smooth nature improves the sliding characteristics. It may also serve to act as a dielectric or insulating coating for certain applications.

  The object of the present invention is to provide a non-stick protective material which is corrosive and very suitable for the oil industry suffering from high temperature environments. Coke deposition in ethylene cracking tubes is a significant problem and the decoking process is expensive and time consuming. A coating of the compounds, compositions and / or materials of the present invention can be deposited on top of the alloy layer to avoid coke deposition.

  An object of the present invention is to provide a protective coating for molten material processes. The amorphous, dense, non-sticky nature of the material of the present invention is well suited to provide a non-stick surface. It can be used as a durable release agent in die casting. Most mold release agents currently used in aluminum and other metal casting processes are polymer systems that are durable only in one casting cycle. The durability and hardness of the coatings of the compounds, compositions and / or materials of the present invention are useful for making them durable over several cycles and will save time and cost (the coatings of the present invention The product lasts twice as long as other coated products and has proven to be an effective non-wetting protective coating for the molten aluminum process and the inventive compounds, compositions and / or materials are enamel Can be deposited on top of the coating, sealing higher porous structures). The present invention has a protective function against other molten materials including molten polymer, molten glass and non-ferrous molten metal as well as molten aluminum.

  The object of the present invention is to provide electrical insulation for many metal and alloy parts used in a wide range of industries. In some cases, both electrical insulation and corrosion resistance are required. The compounds, compositions and / or materials of the present invention can be used as dielectrics suitable for some applications. The pinhole-free properties of the coating are very attractive. Dielectric coatings are desirable, for example, for flexible solar cell metal substrates (next generation requirements). The stability of metals and alloys used in plasma environments within semiconductor or thin film processing equipment is a major concern. Coatings can be deposited on these metals and alloys to provide protection. Furthermore, it is an object of the present invention to provide a low dielectric constant film for semiconductors and a thermally stable low visibility coating for defense applications.

  An object of the present invention is to provide anti-discoloration protective coatings on metals and alloys. Although polymer products are used to deposit protective coatings on these parts (such as doorknobs), they are not durable. The compounds, compositions and / or materials of the present invention are durable and can be transparent so as not to affect the appearance.

An object of the present invention is to protect metal alloys from hydrogen embrittlement.
An object of the present invention is to protect metals and alloys from corrosion and oxidation under thermal cycling conditions while the coating adheres to the substrate.

  An object of the present invention is that such coatings can be deposited on substrates including but not limited to glass, metals, alloys, ceramics and polymers / plastics. A further object of the present invention is to develop a coating material that is very stable and has a low oxygen diffusion coefficient so that an ultra-thin film of material provides sufficient protection to the substrate. This is an important advantage over prior art coating materials (thick, non-hermetic coatings are used, causing cracks during the thermal cycle and flaking off, causing catastrophic failure of the part during use) It is. This is particularly a concern for aerospace and energy applications where very high temperatures are used. Yet another object of the present invention allows the use of such coatings over a wide range of temperatures that are friendly to harsh environments (low temperatures requiring cryogenic temperatures above about 1400 ° C.). Yet another object of the present invention is to take advantage of the low surface energy of aluminophosphate materials that are advantageous in applications where non-wetting or non-tackiness is required. These include, but are not limited to, non-wetting to water, solutions, chemicals, solids, molten salts, molten metals and air pollutants (including organic substances).

  It is an object of the present invention to protect metal and alloy substrates both in oxidizing and reducing the environment. Metals and alloys are used in a variety of environments where gases, liquids and solids are in contact over a range of temperatures. For example, hydrogen or gas that induces a reducing environment may react with metals and alloys to form unwanted reaction products, or hydrogen diffuses into the material and is a well-known phenomenon of hydrogen embrittlement. May invite. Fuel cells, for example, operate in a combination of oxidizing and reducing environments, and the materials used in their construction must be able to withstand various conditions. The compounds, compositions and / or materials of the present invention are used as thin films and provide the necessary protection against the construction of various materials used in harsh environments, especially in many of these applications requiring high temperatures. be able to. Molten materials include, but are not limited to, metal sulfate (eg, sodium sulfate), metal vanadate, molten polymer (hot melt adhesive), molten metal (aluminum, zinc). Used and present in a wide range of industrial processing environments that degrade. Due to its robust nature (low atomic diffusion coefficient), thin films on the order of 100 nm are sufficient to provide the desired protection. The ability to use such thin films is particularly useful because they are thermal cycles and do not crack or flake off. In addition, they are useful in preventing interlaminar delamination of deposited films of the compounds, compositions and / or materials of the present invention and protect the underlying substrate from oxidation or corrosion.

Yet another object of the present invention is to allow organics to self-absorb on the surface of inventive compounds, compositions and / or material films deposited on a substrate. Due to the presence of certain organic pollutants in the atmosphere, the surface of the compounds, compositions and / or materials of the present invention reacts with such organic substances under atmospheric conditions, and the organic materials or modified forms thereof And form a stable bond through a self-absorption process. Such an organic film further reduces the surface energy of the composite structure, thus imparting hydrophobicity or non-wetting properties. The organic film can also be deposited on a compound, composition and / or material film of the present invention, including but not limited to oleic acid and organosilane, using a simple dip coating process. The presence of the organic layer is a Fourier transform infrared spectrometer (absorption at 2994, 2935, 1702, 1396, 1337 and 972 cm ⁻¹ due to organic groups attached to the surface of the compounds, compositions and / or materials of the present invention). Is characterized by observation of organic groups on the surface using

  The organic layer can be deposited on the surface of the compounds, compositions and / or materials of the present invention and promotes hydrophilic behavior in order to promote binding with certain materials. For example, the adhesion of polymers to metals and alloys is poor. Using the surface of the compounds, compositions and / or materials of the present invention as an adhesive and anti-corrosion layer on various polymers and ceramic bonded metals will enhance adhesion. Although the properties of the compounds, compositions and / or surface oxides of the material of the present invention can promote adhesion directly to the polymer, adhesion is further prior to bonding with the polymer or other material. Further enhancement can be achieved by depositing a suitable hydrophilic organic layer on top of the membrane. Thus, the surface of the compounds, compositions and / or materials of the present invention can be conditioned with organic matter to impart hydrophobicity or hydrophilicity.

  Other objects, features, advantages and advantages of the present invention will become apparent from the foregoing description of the gist of the present invention and the various embodiments, which are known for various coatings, protective substrates and / or composites. Will be readily apparent to those skilled in the art. Such objects, features, advantages and advantages will become apparent from the above in view of the accompanying examples, data, drawings and all reasonable conclusions drawn from them or references incorporated herein. .

  Surprisingly, microstructurally dense amorphous aluminophosphate materials should be prepared using low cost precursors of phosphorous pentoxide and aluminum nitrate hydrate in ethanol or other liquid media. I found out that I can. Thermal decomposition of the precursor at temperatures above 500 ° C. provides a stable, microstructurally dense amorphous aluminophosphate material that is resistant to crystallization up to 1400 ° C.

  More importantly, it has been surprisingly found that the precursor solution forms good films and has adhesion to metals and alloys, glass and ceramic substrates. Without being bound by any theory, it is proposed that adhesion is primarily promoted by phosphate bonds between the precursor solution and the components in the metal substrate. As noted above, phosphate bonds are well known to improve adhesion between metals and inorganics and between ceramic materials. The higher curing temperature (500 ° C. and higher) utilized in the present invention helps promote adhesion. At these high temperatures, the precursor decomposes in the atmosphere and induces some oxidation of the metal substrate, leading to metal oxide formation (either as a layer or as a separate island). The phosphorus contained in the precursor binds to the oxide, at least in part, by phosphate bonds, allowing for good adhesion between the substrate and the deposited film after curing. Prior art methods do not provide this advantage. This results in a well bonded film without the need for any special pretreatment or separate deposition of the underlying layer to increase tackiness.

  Embodiments of the aluminophosphate compounds, compositions and / or materials of the present invention are commercially available from Cerablak ™ from Applied Thin Films. Various considerations relating to this invention are disclosed in US Pat. Nos. 6,036,762 and 6,461,415, pending patent applications 10 / 266,832 and PCT / US01 / 41790. And is hereby incorporated by reference for its full purpose.

Subsequent analysis of metallized films with the compounds, compositions and / or materials of the present invention shows different “interface layer” properties in their chemical form compared to the substrate or deposited film. When observing coated metals and alloys, various layers often appear under the optical microscope, directly below the transparent film of the compounds, compositions and / or materials of the present invention. For example, X-ray diffraction of a film deposited on mild steel shows a peak corresponding to the formation of iron oxide (Fe ₂ O ₃ ). However, in other cases, the interface layer is observed indirectly. For example, a TEM micrograph of a film deposited on stainless steel does not show the presence of, for example, an intermediate layer, but FTIR and Raman spectral analysis show that the compounds, compositions and / or materials of the invention or substrate or substrate Absorption corresponding to bonds that cannot be assigned to any of the oxides that may have formed. M-O-P bonds are believed to form at the interface during the curing process that helps to achieve the observed good adhesion. Thus, the structure of the final coated material can be defined to include components between the substrate and the aluminophosphate, in addition to the interface or adhesive layer, and the phosphate group of the continuous phosphate bound metal oxide or film. May include an oxide layer combined with or a mixture thereof. Thus, the benefit of utilizing a precursor system with a suitable curing process results in a good adherent glassy film.

  Exposing the coated alloy to higher temperatures (above 800 ° C.) substantially reduces oxide formation directly under the deposited coating, and further, oxide scale compositions are observed with uncoated materials Is observed to be substantially different. Without being bound by any theory, it is believed that the coating, due to its low oxygen diffusion coefficient, establishes a low oxygen partial pressure at the coating metal interface at a given temperature, which leads to the formation of stable oxides in the alloy composition. help. Further evidence of this phenomenon is presented here by specific examples.

  By using a dip coating process (described in detail below), a thin, high density, smooth, airtight, transparent, continuous glassy coating is formed on the substrate surface. The precursor solution has a sufficiently low viscosity so that a uniform film can be deposited on the composite shaped substrate. The various examples described below provide evidence of its formation, durability and stability under harsh exposure conditions. Certain monomer or polymer species in the precursor solution facilitate the formation of an airtight and continuous film. During the curing of the sol-gel film, many events, stiffening resulting in solution evaporation, gelation and film condensation and densification occur almost simultaneously. If film stiffening occurs in the early stages, there is less chance of relaxation, the film will become porous and / or cracked. If not wishing to be bound by any theory, the combination of low hydrolysis-condensation rate and rapid removal of organic material can be achieved using the precursor solution discussed in the present invention without cracks and airtightness. It is a clue to form a simple coating.

  Materials tend to form over a wide range of aluminophosphate compositions and stoichiometry so that a particular Al / P ratio can be selected to meet the needs of a particular application. Al-rich compositions are more thermally stable in amorphous form. Stoichiometric or P-rich compositions also produce dense materials, but have limited thermal stability. However, they can be useful for applications where the temperature limit is 1000 ° C. or less. The stoichiometry of aluminum phosphate refers to a compound or composition having an aluminum / phosphorus ratio of about 1/1.

  Most surprisingly, it has been found that the material has a very low oxygen diffusion coefficient so that it can function as an excellent protective coating in substrates susceptible to high temperature oxidation. Because of this unique property, in order to function as a protective hermetic coating, it is about 0.5 micron thick, preferably about 0.5 micron thick, most preferably about 1 micron thick, with a very thin high thickness of material. It is sufficient to deposit a film of density. Such thin coatings are less susceptible to cracking and delamination due to mismatched thermal expansion between the coating and the substrate.

  Also, low cost precursor materials and deposition methods allow their deposition as an overcoat or undercoat of conventional coatings. For example, it is a well-known technique to deposit a thick (several mil) metal alloy coating (eg, MCrAlY) on a substrate used in turbine engines, ethylene cracking furnaces, and the like. The deposition of an ultrathin overcoat of the compounds, compositions and / or materials of the present invention improves the life of the underlying coating and thus strengthens the substrate with negligible additional cost. An undercoat in MCrAlY with TBC on the top surface helps to form a stable alumina thermally grown oxide film during use. Furthermore, the compounds, compositions and / or materials of the present invention can be applied in the field during outages or periodic maintenance inspections. Various examples of the ability of metals, alloys and ceramics to protect against high temperature corrosion and oxidation are given below.

  Accordingly, from a broader perspective, the present invention includes a composite comprising a metal substrate, a substantially amorphous, substantially nonporous aluminophosphate film, and components therebetween. Such components include phosphate groups bonded in interaction with the oxide of the metal component of the substrate. The aluminophosphate membrane contains an aluminum content that is approximately stoichiometric, less than stoichiometric, or greater than one mole of phosphorus content in the membrane.

  In one embodiment, such composite membranes further comprise nanoparticles such as, but not limited to, particles comprising carbon, metal compounds, and mixtures thereof. The metal compound nanoparticles include, but are not limited to, those described herein, but can also be selected from those materials described in the above-incorporated patents and patent applications. Nevertheless, in one embodiment, the substrate can be a steel alloy such that the phosphate groups described above interact and bind with iron oxide, chromium oxide, or combinations thereof, and do so. The interaction is promoted in situ during curing in the formation of the film or coating. Similarly, regardless of the nanoparticle content or the substrate itself, such composite aluminophosphate films can be from about 0.05 microns to about 10 microns thick. In various embodiments, such a film can be as thick as required, from about 0.1 microns to about 1.0 microns. As described elsewhere, depending on the film thickness, the film can be transparent or opaque, as required by the desired end-use application.

  For one thing, the present invention can provide a high temperature stable composition comprising an aluminophosphate compound that is substantially amorphous with the carbon nanoparticles therein. As noted above, the aluminophosphate compound of such compositions can vary beyond the stoichiometric range. In one embodiment, stability of the composition may be necessary at temperatures up to about 1400 ° C. or above, and the aluminophosphate compound has an aluminum content greater than stoichiometric per mole of phosphorus content. Nevertheless, such compositions can optionally further contain nanoparticles of the metal compounds described above. Alternatively, compared to the prior art, the substantially amorphous aluminophosphate compound is free of or substantially absent chloride ions, such absence being more than disclosed in the prior counterpart patents. Means low chloride content or concentration.

  For one, the present invention can include a method using an aluminophosphate compound to reduce the surface energy of the substrate. Such a method comprises (1) providing a precursor to an aluminophosphate compound, such precursor further comprising an aluminum salt and phosphorus pentoxide in a liquid medium, (2) applying the medium to a substrate. And (3) heating the medium for a time and at a temperature sufficient to provide a non-wetting, substantially amorphous, substantially nonporous aluminophosphate compound on the substrate. In one embodiment, as described herein, and according to the incorporated patents and patent applications, the liquid medium may include an aluminum salt and an alcohol solution of phosphorus pentoxide. As described herein, application techniques include, but are not limited to, dip coating and spraying. An embodiment that illustrates such a method is the use of an aluminophosphate compound on the substrate due to non-wetting properties that interact with molten aluminum.

  Thus, the present invention can also include a composite comprising a metal substrate and a substantially amorphous, substantially nonporous aluminophosphate film on the substrate, whereby the composite is And, as understood in accordance with the structural, compositional and physical relationships described herein, the surface energy alone, by using such a substrate, results in a lower surface energy than is initially available. Have.

In general, many polymers or organic materials are known to have the lowest surface energy because the hydrocarbon group is terminated with a fluorine-based compound to further reduce the surface energy. Such a surface is non-tacky to such a surface and imparts non-wetting or hydrophobic properties. Polytetrafluoroethylene (PTFE) is the most famous non-stick material widely used in many applications including cookware. The surface energy value of the PTFE surface is measured to be about 18 mN / m ² . However, the surfaces of metals, ceramics and glasses have relatively high surface energies, and generally the metals and alloys exhibit the highest surface energy, and glass is the lowest of these materials. Has a value. For many applications, it is desirable to reduce the surface energy of metals, ceramics and glasses. Surface modification techniques, including polymer deposition, are commonly used in industry to reduce surface energy. Such properties can enhance the flow characteristics of fluids (including molten polymers, oils, aqueous solutions and other organic solvents), maintaining a relatively clean surface and providing a low friction surface.

The polymer coating is not durable. The material of the present invention deposited as a relatively smooth, substantially non-porous, amorphous film on the steel component provides low surface energy (˜32 mJ / m ² ). This is relatively close to the surface energy of certain polymers such as polypropylene. Due to the robust, thermally stable, durable, wear-resistant and corrosion-resistant film properties, the low surface energy of the material of the present invention can be used as a protective film for high temperature applications (eg, molten metal processing) ) Can be used for many applications. Furthermore, the film properties that reduce the surface roughness of the substrate further enhance the properties during use. Further, the surface energy can be further reduced by changing the Al / P composition and other processing parameters.

  For the purposes of the compounds, compositions, materials and / or methods of the present invention, unless otherwise indicated, the following expressions and terms have the meaning given by those skilled in the art or are indicated below: Will be understood.

“Aluminophosphate” means a compound, composition and / or material comprising aluminum and phosphate. Without limitation, such compounds, compositions and / or materials exhibit the formula AlPO ₄ , where the aluminum and phosphate components are of stoichiometric relation known to those skilled in the art that recognize the present invention. Can vary beyond range.
“Corrosion” means any change in the metal that results in oxidation (conversion) to the corresponding metal cation in the formation of species X. Such species X are usually (optionally hydrated) metal oxides, carbonates, sulfites, sulfates or other sulfides (eg in the case of the action of Ag H ₂ S).

"Metal substrate" means any substrate that consists entirely of one or more metals or that has at least one metal layer on its surface.
“Metal” and “metallic” mean not only pure metals, but also mixtures of metals and metal alloys, which may be susceptible to corrosion and are relevant to the present invention. May be for use.
“On” relates to the compounds, compositions and material coatings of the present invention and those in relation to the corresponding substrate, regardless of one or more layers, components, films and / or coatings therebetween. The position or arrangement of the compound, composition and material coating.

  Thus, the present invention can be applied particularly advantageously to metal substrates comprising at least one metal from the group consisting of iron, aluminum, magnesium, zinc, silver and copper, although the scope of application of the present invention is these metals Not limited to. Among the metal alloys that may particularly benefit from the present invention, mention may be made in particular of steel, titanium, nickel and copper alloys.

Without limitation, examples of specific applications and uses of the invention include the following.
Construction, eg, steel support and shutter material, face support, shaft support, shafts to join tunnels and structures, insulator structure parts, two metal profile sheets and insulating metal layers Composite sheets, shutters, framing structures, roof structures, accessories and supply pipes, steel protection plates, exterior lights and traffic lights, slides and turnstiles, gates, doors, windows and their frames and panels, from steel or aluminum Gate seals or door seals, fire doors, tanks, collection containers made of iron, steel or aluminum, drums, bats and similar containers, heating boilers, radiators, steam hoilers, turbine parts, internal and non-internal halls, buildings, garages , Garden house, steel or Surface made of aluminum sheet, the surface of the profile, window frames, facing parts, zinc roof;
Vehicles such as magnesium parts, trucks and truck body parts, road vehicles containing or consisting of aluminum, electrical parts, rims, wheels made of aluminum (including chrome plating) or magnesium, engines, copper vehicles Drive parts, in particular shafts and bearing shells, porous mold filling mold parts aircraft, marine screw propellers, boats, nameplates and identification tags;
Home and office parts, eg steel, aluminum, nickel-silver or copper furniture, shelf units, sanitary equipment, kitchen appliances, lighting components (lamps or lighting), solar equipment, locks, appliances, door and window handles, cooking Instruments, flies and heat-resistant products, mailboxes and box-like structures, reinforced cabinets, reinforced boxes, classifications, files, file card boxes, pen trays, stamp holders, pronto plates, screens, identification cards, scales;
Daily necessities such as tobacco cans, cigarette cases, compact, lipstick cases; weapons such as knives and guns, knives or scissors handles and blades, scissors blades; tools such as spanners, pliers, screwdrivers, screws, nails, metal mesh , Springs, chains, iron or steel wool, wire scrubbers, buckles, rivets; sharp products such as shavers, razors, razor blades made of magnesium, tableware knives, forks, spoons, shochu, shovels, scissors, Shafts, meat cleaver, musical instruments, watch and watch hands, jewelry and rings, tweezers, clips, hooks, glasses, grinding balls, trash cans and drainage grids, hoses and pipe clips; sports equipment such as screw-in studs, goal frames.

  Parts including metal parts such as catalytic converters and photovoltaic cells can be coated with the material of the present invention. Alternatively, high emissivity coatings can increase the heat transfer efficiency for industrial and consumer uses such as metal thermal protection systems and glass manufacturing, energy and metal manufacturing, and duct linings, heat resistant wall materials, It may be effective for heat shielding of xenon light and protective coating of high temperature filter for liquid non-ferrous metals.

  The compounds, compositions and / or materials of the present invention are materials based on sol-gel derived amorphous aluminum phosphate. The compounds, compositions and / or materials of the present invention can be synthesized over a wide range of aluminum to phosphorus ratios, including from about 1/1 to about 10/1. The compounds, compositions and / or materials of the present invention are very inert to chemical attack, are thermally stable above 1400 ° C., and are visible in the visible, IR and UV range (200 to 2500 nm). It has sufficient permeability. The high temperature oxidation test shows high impermeability to oxygen permeation.

  The compounds, compositions and / or materials of the present invention are densely deposited on a substrate using a simple dip, paint, spray, flow or spin coating process at relatively low temperatures (500 ° C. or higher). It can be deposited as a thin coating without pinholes (FIG. 1). It has considerable potential to expand on a variety of substrates without significant capital investment to produce a continuous coating. As the covalently bound inorganic oxide increases, the compounds, compositions and / or materials of the present invention become chemically inert (like alumina) and become thermally stable materials. The compounds, compositions and / or materials of the present invention are unique metastable amorphous materials that are stable to temperatures in excess of 1200 ° C. Tests of the compounds, compositions and / or materials of the present invention show the electrical insulating properties of the film and the continuity, hermeticity, and protective properties of the coating.

The species present in the precursor solutions of the compounds, compositions and / or materials of the present invention can be used to derive the properties of the solid compounds and / or materials of the present invention. Based on overall experimental evidence, the main components of the precursor solution are believed to include complexes containing Al-OP bonds. This conclusion is mainly based on the confirmation of Al—O—Al bonds in the precursor solution, dry gel and calcined powder. The ³¹ P nuclear magnetic resonance (NMR) spectrum of the precursor solution shows at least two peaks prominent in the vicinity of −5 ppm and −12 ppm, which are aluminofate with a mixture of alcohol and water molecules coordinated to aluminum. Assigned to complexes (1) and (2), respectively (FIG. 2). Furthermore, ³¹ P NMR analysis of the precursor solution primarily indicates the presence of two phosphate esters bonded to one or two aluminum atoms. The reactivity of these complexes is sterically limited by P = O groups and hydrolytically stable P-OR groups (Sol-gel synthesis of phosphates, J. Livage et al., Journal of Non-Crystalline Solids). , 147 & 148, 18-23 (1992)). Without being bound by any theory, the stability of the complex may limit the condensation of these complexes that form a three-dimensionally expanded Al-OP network (reduces the condensation kinetics). unknown. Thus, the shelf life of the precursor solution is extended and the solution remains transparent for months to years. In addition, alcohol-based solvents provide excellent film-forming capabilities, while the base phosphate chemistry allows chemical bonding that results in strong adhesion to most substrates.

These results support the formation of multi-cation clusters with an Al / P ratio of 2 or higher in the solution resulting in [O = PO—Al—O—Al] cluster formation. Thus, the requirements of both a) P = O and b) Al-O-Al, which are part of the cluster unit, are considered important. This trend is consistently observed in many other synthetic routes that produce the compounds, compositions and / or materials of the present invention. The species common to all solutions that produce the compounds, compositions and / or materials of the present invention are those that comprise at least the [O = P—O—Al—O—Al] bond. FIG. 3 shows the FTIR of the dried powder at 150 ° C. and the product fired at 1200 ° C., respectively. From the FTIR data at 150 ° C., it is clear that both P═O and Al—O—Al species are observed. The observation of P═O extending at a higher frequency (1380 cm ⁻¹ ) indicates that the terminal oxygen atom of the P═O bond is not coordinated.

Also, the study of the development of the compounds, compositions and / or materials of the present invention from the gel state provides interesting insights. In pyrolysis, cross-linking of the [O = P—O—Al—O—Al] moiety ultimately results in a [—PO ₄ —A1O ₄ —A1O ₆ —A1O ₄ —PO ₄ —] fragment in the high temperature amorphous skeleton. Persists over temperature range. The presence of this type of bond in the fired material is established from combined NMR and FTIR spectroscopy data. The compounds, compositions and / or materials of the present invention comprise aluminum tetrahedral coordination in addition to “distorted” octahedral aluminum, the strength of which increases with excess aluminum content. This is different from the limited tetrahedral coordination of aluminum observed in all crystalline polymorphs of AlPO ₄ . ^{The 27} Al NMR data suggests a distorted environment for tetrahedral aluminum, while the corresponding ³¹ P NMR indicates an undistorted environment for the [PO ₄ ] group. Combining these two data, we conclude that the [PO ₄ ] group binds only to the [A 1 O ₄ ] group which binds to the [A 1 O ₆ ] group alternately. Correspondingly, the bending mode vibration of Al—O—Al at 825 cm ⁻¹ in the FTIR spectrum is proportionally approximated by the excess aluminum content, and the [A1O ₆ ] and [A1O ₄ ] polyhedra Suggests a direct bond between them.

  The multi-cluster P—O—A1 complex identified above represents a new synthesis method for amorphous oxide materials. In addition to the precursor system used in this particular case (aluminum nitrate and phosphorus pentoxide in alcohol), basically a composite with P = O and Al-O-Al moieties (they bind to each other) Any precursor system that produces a body produces the compounds, compositions and / or materials of the invention. Regardless of the precursor system used, the formation of these complexes appears to produce the compounds, compositions and / or materials of the present invention. Such composites can be further modified by other additives (silicon, zirconium, lanthanum, titanium) that can potentially enhance amorphous properties or increase the thermal stability of these materials. be able to.

  Many coating techniques can be used with the precursor solution, but dip coating, spraying, painting and flow coating are most frequently used. All are low cost and easy to apply and expand. These techniques can be used successfully in a variety of substrates including metals, alloys, glasses, ceramics, and the like. The compounds, compositions and / or material solutions of the present invention can achieve good wettability when using aqueous solutions, but include alcohols (preferably including, but not limited to, methanol, isopropanol, butanol, etc.). Other alcohols can be used as well), and particularly good wettability when used as a solvent. A number of oxidation studies have demonstrated the hermeticity of the coating and the thin advantages of the compounds, compositions and / or material films of the present invention. The coating on stainless steel can be resistant to processing above 1000 ° C. without cracks.

  The coating composition used according to the invention can be applied to the metal surface by conventional coating methods. Examples of techniques are dipping, spinning, spraying or flashing. Particularly preferred are dipping and spraying.

  The compounds, compositions and / or material solutions of the present invention have been applied in various ways and compositions. The compounds, compositions and / or materials of the present invention are widely used on a variety of substrates including stainless and mild steel, titanium, nickel, iron, aluminum alloy glass, ceramic and carbon, among many other substrates. It is covered. After application of the coating, it is dried to remove the solvent and cured to remove organics and nitrates (or other salt components from the precursor). The coating can be cured in an oven or with a portable quartz infrared heat lamp. The coating cures quickly and is stable. The (final) temperature of the thermal densification can be determined in view of the heat resistance of the metal surface, which temperature is usually at least 300 ° C., in particular at least 400 ° C., particularly preferred Is at least 500 ° C. If the metal surface is sensitive to oxidation, it is recommended that thermal densification be performed in an oxygen-free atmosphere, such as under nitrogen or argon, especially at such high temperatures.

  During the curing process, bonding with the substrate material is promoted. Metal or alloy substrates, in particular, are partially oxidized and then form oxide scales that form strong bonds with the coating material during the curing process (partially or continuously depending on substrate composition, chemistry and surface roughness). In many cases, the precursor solution may also allow direct phosphate bonding of the metal surface to help improve adhesion. Although the exact chemistry of the interfacial layer (present between the substrate and the applied coating) is not known, evidence from optical microscopy, FTIR and Raman spectroscopy and X-ray diffraction shows that the interfacial properties are Or, it is different from the metal surface. This has been observed on both soft steel and stainless steel substrates, as demonstrated in Examples 30 and 31.

  Thus, using a curing temperature of 500 ° C. or higher in an oxidizing environment or in the atmosphere is preferred to obtain a fully cured coating and to achieve good adhesion with the substrate. Although coatings can be cured by prolonged exposure to low curing temperatures, temperatures above 500 ° C. result in partial oxidation of the substrate and promote direct bonding of substrate substituents and phosphate groups. Therefore, it is preferable. One skilled in the art will recognize that the temperature, environment and time of exposure can be adjusted over a wide range to achieve the various objectives discussed above. The use of higher temperatures and higher oxygen partial pressure in the atmosphere is preferred for many applications, preferably for rapid curing, which will reduce manufacturing costs.

  Adhesion with the substrate can be further improved by changing the Al / P ratio by substrate composition and oxide scale chemistry. Excellent adhesion has been achieved with many alloy substrates including steel alloys, nickel, inconel, advanced nickel and titanium alloys, aluminum, copper, titanium and various grades of those alloys. By annealing the coating material at higher temperatures, adhesion can be further improved, but significant substrate oxidation may cause the oxide scale to be sufficiently thick, causing cracks at the oxide scale / substrate interface or May cause destruction. Although annealing at very high temperatures (above 1000 ° C.) may result in some loss of phosphorus in some circumstances, the density properties of the coating are maintained so that protection is still considered good. Further details of the oxidation mechanism in steel and tip alloys are given below in the attached specific examples. Aluminum and its alloys can also be cured by other surface heating techniques such as laser heating, IR lamps, etc. due to their thermal sensitivity. Thus, if heating is limited to the surface of the substrate, the mechanical and chemical properties of the substrate, as compositional or microstructural changes taking place in the substrate may affect its physical and mechanical properties. Degradation can be largely avoided. However, hardening of the coating in the aluminum alloy has been achieved by using a furnace in the temperature range of 500 to 550 ° C. Such a coating alloy shows good properties in the salt spray test and demonstrates good corrosion protection. Application of coatings of the compounds, compositions and / or materials of the present invention to many substrates can be combined with the tempering methods generally used for hardened metals and alloys. This will help reduce the number of process steps required to produce the final product for an application.

  The coating composition applied to the metal surface will then be thermally densified to form a glass layer. Prior to thermal densification, a conventional coating composition drying operation at room temperature and / or slightly elevated temperature will usually occur. It is still noted that thermal densification can also be arbitrarily effective with IR, UV or laser heat sources. It is also possible to produce a structured coating by the selective action of heating on it.

  A slurry is also formed by dispersing the powder in a solution of the compound, composition and / or material of the present invention. Slurry coating increased the thickness or functionality of the coating. Various powders were mixed into the solution. Slurry coating can be applied by any of the coating methods described above. When synthesized as a powder, the compounds, compositions and / or materials of the present invention comprise a glassy carbon nano-inclusion fully embedded in an amorphous material. These carbon inclusions help impart high emissivity properties to the powder. High radiation coatings can be formed by forming a coating from a slurry of the black compound, composition and / or material particles of the present invention dispersed in a solution or in a suitable medium. Moreover, the compound, composition and / or material of the present invention can be used as a protective binder for pigments. It is also possible to synthesize compounds, compositions and / or materials that do not contain carbon by appropriate selection of the precursor composition.

  The low cost associated with the present invention and coating technology allows consideration of options to be combined. It is anticipated that the compounds, compositions and / or materials of the present invention can enhance the oxidation resistance of a wide range of alloys (even high oxidation resistance alloys). It can also be deposited in welded areas where morphological inhomogeneities and compositional variations necessarily exist. The compounds, compositions and / or materials of the present invention can also be applied in the field of remediation and applied to cleaning deposits on cleaning walls or other areas during shutdown. You can also. Spray is a suitable method for depositing the compounds, compositions and / or material coatings of the present invention and can be used in the area of the repair process.

  Inspection of the coated substrate at a magnification of 1000 using an optical microscope shows the continuous nature of the coating. Compliance of the coating of the compounds, compositions and / or materials of the present invention on steel foil proves that there are no signs of delamination of the foil at the point where the foil is bent several times (> 120 °). Thus, it demonstrates the good adhesion of the thin film.

  Thin coatings are often preferred to avoid delamination from heat treatment because of their ease of application at low cost and their compliance in the case of a large CTE match between the substrate and the coating. If an insulating layer is required, a thicker coating is preferred to provide sufficient electrical insulation and is preferred to provide desirable diffusion barrier properties during functional coating layer deposition. Since the compounds, compositions and / or materials of the present invention are very inert to chemical attack and have a low dielectric constant, a good insulator at about 500 ° C., even at a film thickness of about 2000 to 50000 angstroms And function as a diffusion barrier. For the compounds, compositions and / or materials of the present invention, a dielectric breakdown strength of 190 V has been measured at a film thickness of 100 to 500 nm on stainless steel. Its dielectric constant can range from 3.3 to 5.6.

  The compounds, compositions and / or materials of the present invention significantly limit the oxidation of metal / alloy substrates as well as corrosion. In addition to providing protection, the present invention appears to change the chemistry of the growing oxide scale. Perhaps more significantly, the present invention can be used to minimize the effects of accelerated corrosion due to surface roughness, eliminating the corrosion pits often observed in metal oxide / alloy substrates. Thus, the function of the compound, composition and / or material layer of the present invention planarizes defects at the surface and the alloy surface in the early stages of oxidation protecting sharp edges.

  The ability to protect nickel-based alloys at temperatures of 100 ° C. and above for over 100 hours has been successfully demonstrated. Two grades of nickel-based superalloy are coated with the compounds, compositions and / or materials of the present invention (~ 1 micron thick coating by dip coating method) and their oxidation behavior is subject to thermal cycling conditions Researched at. FIG. 4 shows the oxidation behavior of a coated or uncoated alloy. Each data point in the curve represents a thermal cycle (RT-1100 ° C.). Thus, the cumulative exposure time at temperature was about 100 hours. Both coating materials performed very well under exposure conditions, especially for the high temperatures used.

  The compounds, compositions and / or material coatings of the present invention were also tested with Inconel 718 under a heat cycle at 760 ° C. As mentioned above, the coating material is tested in 20 thermal cycles, and the subsequent surface test shown with the compounds, compositions and / or materials of the present invention is effective in its protection, and more importantly, No further cracking or rupture was observed. The compounds, compositions and / or materials of the present invention were used to coat a γ-titanium aluminide alloy and heat treated with an uncoated alloy at 815 ° C. for 100 hours. The uncoated alloy showed extensive growth of rutile titanium and corundum alumina on the surface. As can be seen by X-ray diffraction (FIG. 5), the coated alloy showed a significant reduction in oxide growth. Combining all of these studies suggests that the compounds, compositions and / or materials of the present invention have good potential for use in protecting alloys intended for use in a wide variety of high temperature applications. .

The compounds, compositions and / or material coatings of the present invention have been shown to protect alloys from oxidation. Without being bound by any theory, during the very initial stages of oxidation, only oxides that are stable in a low _P02 environment are formed (usually chromia for steel or alumina for nickel-aluminum based alloys). Thus, it is considered that the alloy is composed of low P _O2 . To illustrate, type 304 stainless steel was half coated with the compounds, compositions and / or materials of the present invention and heat treated in air for 10 hours. The coated half showed a dense, uniform and chromia-rich scale, while the uncoated half showed a non-uniform scale with deep pits of unprotected iron-rich oxide (Figure 6).

  The compounds, compositions and / or materials of the present invention appear to provide significant benefits by modifying the growing oxide. Regardless of the choice of alloy, problems related to roughness or surface defects are significant and will require special pre-treatments that are expensive and environmentally friendly and will create waste. Surface related defects lead to oxidation behavior for uncoated materials. Despite the high quality finish, these factors dominated the oxidation behavior. For the intended application, the alloy material may be finished into a workpiece using a forging process that is certain to create surface defects, and this problem must be addressed. In addition, the compound, composition and / or material coating process of the present invention and the inexpensive nature of the precursor solution may lead to many other, more expensive pretreatments of the alloy surface than the compound, composition of the present invention. And / or depositing a material coating to make it cheaper.

  For thermal coating applications, thick alumina scale growth between the bond coat and the ceramic coating leads to premature defects in TBC. The compounds, compositions and / or material coatings of the present invention can be deposited on a McrAlY type bond coat and then by growth of alumina scale during use by depositing TBC (preferably by electron beam PVD). Limiting the damage of the TBC due to crushing. The standard method used in turbine manufacturing is to peroxidize the bond coat material (MCrAlY type composition) to improve adhesion with the applied thermal barrier coating. Often the reducing environment is used to promote the selective formation of alumina scale (as opposed to spinel and other oxides). See, for example, US Pat. No. 5,856,027 (Murphy). Such treatment with inert gas or vacuum significantly increases manufacturing costs and limits production efficiency. A thin film deposited on MCrAlY may promote the formation of alumina scale, even if it is annealed in the open air. Furthermore, due to the rough surface morphology, sealing defects by coating can provide further benefits. Furthermore, the presence of the oxidation resistant glassy film can provide enhanced protection of the substrate during subsequent use.

  The compounds, compositions and / or materials of the present invention can protect against corrosion of metals and alloys by molten sulfate (which is encountered in combustion applications). Affinity with trisulfate varies depending on the Al / P stoichiometry, and thus an Al-rich composition shows more affinity for aluminum. Non-wetting may be effective in limiting the deposition of ash particles on metal / alloy components used in coal fuel combustion systems and other power plants.

  In order to evaluate the affinity of the compounds, compositions and / or materials of the present invention with sodium sulfate, the coatings were deposited on sapphire plates. Sapphire substrates were selected to avoid oxide scale effects in the affinity test. Sodium sulfate was placed on the coated sapphire piece and annealed to 900 ° C., just above the melting point (884 ° C.). FIG. 7 represents the coated portion after 120 hours of exposure. As is apparent from the micrographs, the compounds, compositions and / or materials of the present invention did not degrade upon exposure, even at a thickness of 1 micron.

  For example, iron and steel products, in particular iron, non-alloy profiles, strips, plates, sheets, coils, wires and pipes, stainless steel or other alloy steel, shiny galvanized or other plating, non-alloyed, Semi-finished forged products made of stainless steel or other alloyed steels; aluminum, especially foils, thin strips, sheets, plates, die-casting, aluminum for press or press, punches, drawn parts; manufactured by casting or electrolytic or chemical processes Coatings to enhance corrosion resistance are suitable for coated metal coatings; and metal surfaces reinforced by coating, glazing or anodizing.

  For example, for jewelry made of gold and platinum, watches and parts thereof, rings, coatings to enhance wear resistance are suitable. For example, anti-diffusion layers are suitable for lead fishing weights, stainless steel diffusion barriers to prevent heavy metal contamination, water pipes, tools or jewelry (anti-allergenic) containing nickel or cobalt. For example, coatings that reduce surface smooth / frictional wear are suitable for seals, gaskets or guide rings.

  Steel, iron, aluminum and other alloys readily corrode in humid and salty environments. The salt spray test is much faster and allows useful tests in a reasonable time. Coatings of the compounds, compositions and / or materials of the present invention on aluminum and carbon steel specimens have been tested for pre-evaluation with a salt spray device and show further resistance to corrosion compared to aluminum specimens. After the test, the uncoated specimen showed corrosion over the entire piece, but only one coated specimen showed very localized corrosion, and most of the coated specimens were substantially corroded. No symptoms are shown. Where the surface finish is uneven, corrosion of the coating pieces often occurs. FIG. 8 shows a specimen coated or uncoated with a compound, composition and / or material of the present invention after a salt spray test.

  Non-wetting behavior is useful to prevent corrosion in humid / rainy or coastal environments. The compounds, compositions and / or materials of the present invention exhibit non-wetting behavior in water and other liquids. Non-wetting is mainly due to the low surface energy associated with the degree of covalent valence. It may function as an antistatic film that prevents solid molecules such as dust or lint from adhering to the surface.

  Light transmission is important for many applications. Glass microscope slides coated with the compounds, compositions and / or materials of the present invention were compared to uncoated slides. The compound, composition and / or material has been shown to transmit radiation between 200 and 2500 nm. The coating was applied to a sapphire plate and the permeation characteristics were compared to an uncoated sapphire piece cut to the same size. Two coated pieces were tested, one with a thicker coating than the other. FIG. 9 shows the permeability of a coated versus uncoated sapphire plate.

  The compounds, compositions and / or materials of the present invention can be used in protective coatings for coke. Their non-tacky, thermal stability and protective properties are very suitable for use in the petroleum industry experiencing corrosive and high temperature environments. Coke deposition in ethylene pyrolysis tubes is a significant problem. The decoking process is expensive and time consuming. The compounds, compositions and / or materials of the present invention can be deposited on the alloy surface to avoid coke deposition. Coke formation is facilitated by a catalytic reaction between the metal substrate and hydrocarbons present in the gas vapor. A substantially non-porous membrane, preferably an airtight membrane, can function as a good barrier to prevent contact between the metal and the hydrocarbon. Furthermore, carbonization of the metal substrate degrades its mechanical properties. The coating may be useful for preventing carbonization of metals and alloys.

  Still other high temperature applications of the compounds, compositions and / or materials of the present invention are their coatings for high temperature protection of metal or alloy based thermal protection systems (TPS) used in launch rockets (RLV). Related to use. Such materials provide oxidation protection to the underlying substrate and high emissivity characteristics. The powder retains black or dark color at 815 ° C. for 100 hours or more and 1100 ° C. for 24 hours or more, and maintains high emissivity.

  The invention has also proven to protect the substrate from attack from molten non-ferrous metals such as aluminum and zinc and molten polymers. The low surface energy of the compounds, compositions and / or materials of the present invention makes it possible to retain non-wetting properties for these and other materials.

  The compounds, compositions and / or materials of the present invention can also be used to provide a low friction surface. The compound, composition and / or material coating of the present invention on a highly polished 440C stainless steel substrate was measured to be about 0.1.

  The compounds, compositions and / or materials of the present invention exhibit good adhesion to metals, alloys and ceramic / glass substrates in heat treatments that form inorganic materials. When deposited on a metal or alloy, the heat treatment makes it possible to form a very thin oxide scale on the substrate, which improves the adhesion of the compounds, compositions and / or materials of the invention to the substrate. Strengthen.

  A variety of chemical nanoparticles or nanocrystals can be used to induce a variety of functions, including but not limited to optical, chemical, catalytic, physical, mechanical, and electrical properties. Can be embedded or enclosed. Prior art coatings are not strong enough to protect the nanocrystals, and the process of nanocomposites with porous hosts will be an important issue.

  The following examples and data, together with reference figures, provide various aspects relating to the compounds, compositions, materials and / or methods of the present invention, including the manufacture, application and / or use of corresponding films and coatings on various substrates. And exemplify features. Such compounds, compositions and / or materials can be obtained by the synthetic methods described herein. In comparison with the prior art, the present invention provides unexpected and unexpected results and data that are contrary to them. The utility of the present invention is exemplified by the use of several aluminophosphate compounds, compositions and / or materials and complexes thereof. It will be appreciated by those skilled in the art that similar results can be obtained with a variety of other aluminophosphate compounds, compositions and / or materials, which are within the scope of the present invention.

Example 1
264 g Al (NO ₃ ) ₃ .9H ₂ O is dissolved in 300 ml ethanol. In a separate container, 25 g of P ₂ O ₅ (or other soluble phosphate ester) is dissolved in 100 ml of ethanol that promotes the formation of phosphate ester, and this solution is then added to the aluminum-containing solution. The solution is refluxed for a time sufficient to promote the formation of a complex ester containing Al—O—P groups. This solution is clear and stable for a long time.

Example 2
219 ml of triethyl phosphate was mixed with 84 g of Al (NO ₃ ) ₃ .9H ₂ O in 181 ml of ethanol. After stirring for 30 minutes, the mixture was dried to form a gel powder and annealed at 1100 ° C. for 1 hour in air. The resulting X-ray diffraction pattern shows a very crystalline aluminum phosphate and alumina phase, which indicates that this mixture does not form an amorphous, aluminum rich aluminum phosphate. The ³¹ PNMR of the solution shows a peak near 1 ppm, indicating that phosphorus is not effectively complexed with aluminum (FIG. 11).

Example 3
The mixed solution of Example 2 was refluxed. After various periods, some of the mixture was dried for 1 hour at 150 ° C. to obtain a gel powder and then annealed in air for 1 hour at 1100 ° C. As the reflux time increased, the amount of amorphous aluminum phosphate increased. After 3.5 days of reflux, a substantially amorphous phase had formed. ³¹ P NMR of the solution showed a peak at -5 ppm metal. This indicates that aluminum is complexed with phosphorus (FIG. 12).

Example 4
119.28 g Al (NO ₃ ) ₃ .9H ₂ O was dissolved in 510 ml l-butanol. In a separate beaker, the appropriate molar amount of phosphorus pentoxide was dissolved in 31 ml l-butanol. These two solutions were mixed to prepare a 1.75 / 1 Al / P-based l-butanol solution. The solution was dried for 1 hour at 150 ° C. to obtain a gel powder and then annealed in air at 1100 ° C. for 1 hour. A jet black powder (black due to the presence of residual carbon encapsulated in an amorphous matrix) was obtained and an X-ray diffraction pattern showed that the powder was substantially amorphous. TEM analysis showed that the size of the carbon nano-containing material was larger than the powder obtained from the solution of Example 1.

Example 5
A test piece of Inconel 718 was dip coated with the solution of Example 1 and cured with an IR lamp for 10 minutes. The specimen was heat treated according to the setup in Table 1 and tested under an optical microscope after 20 cycles. Although some cracks were shown at the edges, it was found that the other regions had little cracks and the coating had no further cracks compared to the as-deposited coating. This indicates that the thin film properties of the deposited film of the material of the present invention do not cause cracking from thermal stress even if the thermal expansion mismatch between the substrate and the material of the present invention is significant.

Table 1 shows the thermal cycle profile of Example 5. Example 6
A piece of stainless steel was dip coated with the solution of Example 1. The specimen was heated with an IR lamp for a time sufficient to cure the film (removing all of the organics and nitrates) in order to dry it with an air stream and form a substantially inorganic material. The resulting coating was uniform and free of cracks.

Example 7
Stainless steel specimens were coated with a roller using the solution of Example 1. The roller soaked the precursor solution fully and quickly and firmly rotated most of the stainless steel specimens. The specimen was then heat treated with an IR lamp (as in Example 6) for a time sufficient to remove all organics and nitrates. The specimen was heat treated in air at 900 ° C. for 30 minutes to coat a portion of the substrate while being glossy, while the uncoated site exhibited dullness due to the formation of a substantially larger oxide scale ( FIG. 13).

Example 8
2.2 g of finely pulverized (submicron to 2, 3 micron) amorphous aluminum phosphate powder (black) obtained by the method of the example described above was dispersed in 12 ml of ethanol. Was added to 12 ml of the mixed solution obtained in step 1 to prepare a slurry for coating application. This slurry solution was used to coat a type 304 stainless steel piece as in Example 7 to obtain a composite coating consisting of powder dispersed in an amorphous matrix derived from the solution portion of the slurry. The resulting coating was free of cracks and had amorphous aluminum phosphate powder distributed in amorphous aluminum phosphate. The coating was substantially dark in appearance due to the presence of particles in the composite coating.

Example 9
An as-machined graphite sample was coated with the material of the present invention and annealed at 800 ° C. in air for 2 hours with uncoated pieces. The coated pieces retained physical dimensions to a substantially greater degree than the uncoated pieces, as shown in FIG. This suggests that the materials of the present invention are effective in providing oxidation protection to graphite and carbon based materials including composites.

Example 10
19.47 g of P ₂ O ₅ was dissolved in 200 ml of ethanol. In another container, 180.68 g of Al (NO ₃ ) ₃ .9H ₂ O was dissolved in 400 ml of ethanol. In a third container, 16.32 g of La (NO ₃ ) ₃ .6H ₂ O was dissolved in 100 ml of ethanol. All three solutions were mixed and stirred. A clear solution was obtained. Some of the solution was dried at 150 ° C. in a convection oven and annealed at 1100 ° C. for 1 hour. La ₂ P ₄ O ₁₃ crystals and the predominant amorphous aluminum phosphate were confirmed by X-ray diffraction (FIG. 15).

Example 11
A zirconium-containing solution was prepared using the same method as in the previous example. 6.46 g P ₂ O ₅ was dissolved in 70 ml ethanol. In another container, 59.9 g of Al (NO ₃ ) ₃ .9H ₂ O was dissolved in 140 ml of ethanol. In a third container, 1.49 g of ZrO (NO ₃ ) ₃ .xH ₂ O was dissolved in 10 ml of ethanol. All three solutions were mixed and stirred. Some of the solution was dried at 150 ° C. in a convection oven and annealed at 1100 ° C. for 1 hour. ZrO ₂ crystals and dominant amorphous aluminum phosphate were confirmed by X-ray diffraction (FIG. 16). The relative amount of zirconium oxide nanocrystals depends to some extent on the storage time of the precursor.

Example 12
Similar to the previous example, a silicon-containing solution was prepared using a similar method. 8.47 g of P ₂ O ₅ was dissolved in 90 ml of ethanol. In another container, 78.6 g of Al (NO ₃ ) ₃ .9H ₂ O was dissolved in 174 ml of ethanol. In a third container, 1.7 g of tetraethylorthosilane was dissolved in 15 ml of ethanol. All three solutions were mixed and stirred. Some of the solution was dried at 150 ° C. in a convection oven. Some of this dry powder was annealed at 1400 ° C. for 10 hours. Mullite crystals and predominant amorphous aluminum phosphate were confirmed by X-ray diffraction (FIG. 17).

Example 13
Similar to the previous examples, a titanium-containing solution was prepared using the same method. 0.2 ml nitric acid was mixed with 9.84 ml deionized water. 2 ml of isopropoxide titanium was added to the acidified aqueous solution to obtain a white precipitate. This mixture was added to 86 ml of the aluminum phosphate solution of Example 1. The mixture was dried at 150 ° C. and annealed at 1000 ° C. for 1 hour. X-ray diffraction confirmed the presence of titanium oxide (anatase) and the dominant amorphous aluminum phosphate (FIG. 18).

Example 14
The solution of Example 1 was heat treated at 1100 ° C. for 1 hour. The powder was ground to a size of 10 to 20 microns. The obtained powder was jet black, and it was confirmed by an X-ray diffraction pattern that the powder was substantially amorphous.

Example 15
The powder of Example 4 was tested with TEM. Transmission electron microscopy showed a glassy carbon nano-content embedded in an amorphous matrix of the material of the present invention. These inclusions have a size of about 2 to 4 nm to around 10 to 40 nm (FIG. 19). The inclusion was typically the appearance of glassy carbon, and EDS evidence showed that these pieces contained mainly carbon.

Example 16
The powder of Example 14 was dispersed in the mixed solution of Example 1. This slurry was applied on an alumina substrate. The coating was dried in a stream of air until the solvent evaporated and then heat cured above 500 ° C. The total hemispherical emissivity of the coating at room temperature is 0.917, measured from 2 to 20 μm.

Example 17
The coating of Example 16 was heat treated in air at 815 ° C. for 100 hours. The total hemispherical emissivity of the coating at room temperature is 0.908, measured from 2 to 20 μm. This suggests that the carbon nano-inclusions are not oxidized and are well protected by the substantially non-porous, dense matrix of the material of the present invention.

Example 18
The coating of Example 16 was heat treated in air at 1100 ° C. for 24 hours. The total hemispherical emissivity of the coating at room temperature is 0.902, measured from 2 to 20 μm. As in Example 17, the protection of carbon was demonstrated at these elevated temperatures.

Example 19
The mixed solutions of the examples were modified by adding organic components to produce a thicker film without cracks. A piece of 1018 carbon steel was coated with the solution described above to produce a relatively thick (average> 1 micron) coating that was substantially free of cracks. The amount of organic addition can be varied to obtain a thickness width of the deposited film. Coated 1018 specimens, together with uncoated specimens, were subjected to the conditions specified in the ASTM B117 test for 4 days in a salt spray chamber. The coated specimen was substantially free of corrosion, but the coated specimen was almost completely corroded. This indicates that the thick film coating of the material of the present invention is substantially free of cracks and pinholes.

Example 20
Using the method described in Example 19, a substantially opaque, dark-appearing inorganic coating can be produced on metals and other substrates. A small piece of stainless steel was coated to give a black coating. The coating is substantially free of cracks or holes, is hard and wear-resistant and can have good weather resistance compared to conventional black paint. Good adhesion also promotes excellent tack as described in the specification of the patent application.

Example 21
An alcohol solution containing silver ions was added to the mixed solution of Example 1. This solution was used to coat soda lime glass slides. The applied coat was dried with a stream of air to remove the solvent and cured to form a substantially transparent inorganic coating.

Example 22
A slurry coating as described in Example 16 was applied to a stainless steel specimen. The coated sample was impregnated with pure molten aluminum at 760 ° C. and condensed. No noticeable wetting of aluminum was observed at the coated site of the specimen compared to the full coverage of the uncoated site impregnated in molten aluminum. Thus, chemical stability and affinity with molten aluminum and good non-wetting were proved (see FIG. 20).

Example 23
1018 carbon steel was dip coated using the mixed solution of Example 1. The coating was dried with an air stream until the solvent had evaporated, then heat treated at 500 ° C. in air for 30 minutes. X-ray diffraction of the sample surface showed the predominant Fe ₂ O ₃ oxide scale grown on the surface and some Fe ₃ O ₄ . Also, an uncoated piece of 1018 carbon steel was heat treated at 500 ° C. for 30 minutes. X-ray diffraction of the surface showed the formation of predominant Fe ₃ O ₄ and very little Fe ₂ O ₃ (FIG. 21). Fe ₂ O ₃ is a substantially better protective oxide scale than Fe ₃ O ₄ . This also demonstrates the ability of the material film of the present invention to substantially change the oxide scale growth chemistry of the metal substrate.

Example 24
A piece of stainless steel was dip coated with the mixed solution of Example 1 and cured in air at 500 ° C. or higher for several minutes. Raman spectra of both the coated and uncoated areas of the specimen were taken. The spectrum of the coated site of the sample recognized three peaks that did not correspond with the uncoated sample or crystalline aluminum phosphate or with the amorphous aluminum phosphate obtained using the method of the present invention. This suggests a peak corresponding to the material formed near the interface (interface layer) between the coating and the substrate. The exact chemistry or nature of the interfacial layer is not known, but this is believed to help in improving the adhesion of the coating. The nature of the interface layer may vary depending on the chemistry of the substrate composition and the heat treatment performed during or after coating deposition (FIG. 22).

Example 25
A piece of stainless steel was dip coated with the mixed solution of Example 1 and cured using the method of Example 24. The coated specimen was exposed to the atmosphere for several days. The FTIR spectrum collected from the surface shows the presence of organic species w (FIG. 23). Organic bonding indicates that it is strong, further helps reduce surface energy and provides a substantially non-wetting surface.

Example 26
The sample of Example 20 was impregnated with molten aluminum at 760 ° C. and condensed. The majority of the coating site is shown to be completely non-wetting to the molten aluminum.

Example 27
A piece of steel was partially coated with the mixed solution of Example 1. The specimen was dried with air flow and heated at 500 ° C. for a time sufficient for the film to cure (removing all organics and nitrates) to form a substantially inorganic material. The surface energy of the coated and uncoated heat treated samples was measured. The surface energy of the coating material was 31.89 mJ / m ² .

2 is a cross-sectional TEM micrograph showing a well-adhered, thin, uniform, dense and airtight film of a compound, composition and / or material of the present invention on AUS304 stainless steel. 2 is a chemical structure of an aluminophosphate complex present in a precursor solution of a compound, composition and / or material of the present invention. (A) FTIR spectrum of the compound, composition and / or powder material of the present invention of Al / P = 1.75 / 1 heat-treated in air at 150 ° C. and (B) 1100 ° C. 2 is a plot showing a comparison of specific weight changes of coated and uncoated nickel-based superalloy specimens exposed to 1100 ° C. in air for 100 hours with a 1 hour thermal cycle. 2 shows X-ray diffraction of a coated and uncoated gamma titanium aluminum alloy showing significant oxide growth on the uncoated substrate and minimal oxide growth on the coated substrate. 2 is a cross-sectional SEM micrograph of coated (left) and uncoated (right) AUS304 stainless steel heat treated at 1000 ° C. for 10 hours. FIG. 2 is a cross-sectional SEM micrograph of a thin film of a compound, composition and / or material of the present invention showing affinity with molten sodium sulfate at 900 ° C. for 120 hours in air, containing sulfur as in a coal-fired power plant Shows the utility of the present invention to protect metal components from corrosion in the environment. FIG. 4 shows coated and uncoated aluminum 2024 alloy after 115 hours exposure to salt spray using ASTM B-117 specification. FIG. 4 shows transmission spectra of a compound, composition and / or material-coated sapphire of the present invention (upper two lines) and uncoated sapphire (lower line). Coating (3) and adhesive layer (2) of the compounds, compositions and / or materials of the present invention formed and promoted in situ while being deposited on a metal or alloy substrate (1) It is a schematic diagram which shows. A) Powder X-ray diffraction pattern of material fired from Example 2 showing crystalline aluminum phosphate and alumina corundum, B) Resonance spectrum at -1 ppm corresponding to unreacted triethyl phosphate. It is a ³¹ PNMR spectrum of the solution. A) ³¹ P NMR spectrum of the solution of Example 3 showing the resonance spectrum at −5.9 ppm corresponding to the aluminophosphate complex, B) Powder of the calcined material from Example 3 showing the predominant amorphous aluminum phosphate It is an X-ray diffraction pattern. It is a photograph which shows the sample of Example 9 after annealing at 900 degreeC for 30 minutes in the air. A piece of graphite that has been coated with amorphous aluminum phosphate (left), as-formed (no heating), and uncoated (right). The left and right samples were heat treated at 800 ° C. for 2 hours in air. 3 is a powder X-ray diffraction pattern of a material fired from Example 10. FIG. The peaks around 20.5, 20.5, 21.5, and 35 of the 2θ values are aluminum phosphate nanocrystals embedded in the amorphous phosphate matrix material. The other peak corresponds to La ₂ PO ₄ . CuKα radiation was used. 4 is a powder X-ray diffraction pattern of the material fired from Example 11. FIG. The peaks around 20.5, 20.5, 21.5, and 35 of the 2θ values are aluminum phosphate nanocrystals embedded in the amorphous phosphate matrix material. The peak around 30 of the 2θ value (labeled with ^* ) is from tetragonal zirconium oxide. Based on the X-ray data, the size of the tetragonal zirconium oxide nanocrystals is 0.5 hours after annealing at 1100 ° C., then about 7 nm, 50 hours, after annealing at 1200 ° C., 26 nm, 10 hours, 1400 ° C. air. 170 nm after annealing in. CuKα radiation was used. 2 is an X-ray diffraction pattern of a material fired from Example 11. FIG. The peaks around 20.5, 20.5, 21.5, and 35 of the 2θ values are aluminum phosphate nanocrystals embedded in the amorphous phosphate matrix material. The peaks around 16 and 26 (labeled with ^* ) are from mullite (A1 ₆ S ₁₂ O ₁₃ ). The size of the mullite nanocrystal is 50 nm after annealing at 1200 ° C., then 100 nm, 10 hours, and after annealing at 1400 ° C., 170 nm. CuKα radiation was used. 4 is an X-ray diffraction pattern of a material fired from Example 13. The peaks around 20.5, 21.5, and 35 of the 2θ values are from aluminum phosphate nanocrystals. The peaks near 26 and 37 are from anatase titania nanocrystals. The size of the titania nanocrystal is about 7 nm. CuKα radiation was used. It is a transmission electron micrograph which shows the nano content of glassy carbon in the powder of the compound of the present invention, a composition, and / or a material. FIG. 3 is a photograph of a half-coated stainless steel specimen after impregnation in molten aluminum (˜750 ° C.) showing non-wetting properties. The broken line indicates the impregnation line in the molten aluminum. 2 is an X-ray diffraction pattern of 1018 carbon steel heat treated at 500 ° C. for 30 minutes. A) Coated with the aluminophosphate of the present invention, B) Uncoated. ^* Indicates a substrate, black diamonds indicate Fe ₃ O ₄ , and + indicates Fe ₂ O ₃ . 2 is a Raman spectrum of a coating of the aluminophosphate material of the present invention on stainless steel. The labeled ^* peak is from the adhesive layer between the coating and the substrate. 2 is a grazing angle FTIR spectrum of stainless steel coated with a thin film of an aluminophosphate compound, composition and / or material of the present invention after exposure to air. Do ry. The labeled ^* peak indicates organic matter absorbed on the coating surface.

Claims (22)

  A composite comprising a metal substrate, a substantially amorphous, substantially nonporous aluminophosphate film and a component therebetween, said component interacting with the oxide of the metal component of the substrate A complex containing   The composite of claim 1, wherein the aluminophosphate membrane has an aluminum content selected from less than stoichiometry, greater than stoichiometry and stoichiometry, the content being a molar ratio to phosphorus.   The composite of claim 1 further comprising nanoparticles selected from carbon and metal compounds.   The composite of claim 1 wherein the substrate is a steel alloy and the oxide is selected from iron oxide and chromium oxide.   The composite of claim 1 wherein the membrane has a thickness of from about 0.05 to about 10 microns.   The composite of claim 1, wherein the membrane has a thickness of from about 0.1 to about 1.0 microns.   The composite of claim 5 further comprising an organic component on the membrane.   The composite of claim 5 wherein the membrane is opaque.   A high temperature stable composition comprising a substantially amorphous aluminophosphate compound and carbon nanoparticles therein.   The composition of claim 9 further comprising nanoparticles of a metal compound.   10. The composition of claim 9, wherein the aluminophosphate compound has an aluminum content selected from less than stoichiometry, greater than stoichiometry and stoichiometry, wherein the content is a molar ratio to phosphorus.   The composition of claim 11 wherein the aluminophosphate compound has an aluminum content greater than stoichiometric.   The composition of claim 9 comprising a coating on a substrate.   A high temperature, stable, substantially amorphous aluminophosphate compound having an aluminum content proportional to phosphorus and substantially free of chloride ions.   The compound of claim 14 further comprising carbon nanoparticles.   15. The compound of claim 14, further comprising metal compound nanoparticles.   15. The compound of claim 14, having an aluminum content selected from less than stoichiometry, greater than stoichiometry and stoichiometry, the content being proportional to phosphorus. A method of using an aluminophosphate compound to reduce the surface energy of a substrate, the method comprising:
Providing a precursor of an aluminophosphate compound, the precursor containing an aluminum salt and phosphorus pentoxide in a liquid medium;
The medium is applied to a substrate and the coated medium is heated for a time and temperature sufficient to provide a non-wetting, substantially amorphous, substantially nonporous aluminophosphate compound on the substrate. A method comprising:   The method of claim 18 wherein the liquid medium is an alcohol solution of an aluminum salt and phosphorus pentoxide.   20. The method of claim 19, wherein the application is selected from dip coating and spraying.   The method of claim 18, wherein the aluminophosphate compound on the substrate is non-wetting to the molten aluminum. A composite comprising a metal substrate, a substantially amorphous, substantially nonporous aluminophosphate film on the substrate, wherein the composite has a surface energy of about 32 mJ / m ² .

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