Metal components with silicon-containing protective coatings and methods of forming such protective coatings

The present invention refers to coated metal parts, and more specifically, pure chromium-free protective metal coatings with chromium-free protective chromium-free protective coatings chromium-free metal members.

BACKGROUND OF THE INVENTION [0002] Inorganic layers and coatings are often produced on the basis of a chromium-free metal element to protect and cover the chemical resistance and chemical resistance. However, zinc can be applied in an electrochemical manner by galvanizing, or by dip methods, these zinc protective coatings. To prevent coating in the form of chromosols, as a pre-treatment before applying zinc. However, the chromate coating process poses a threat to the environment and health,

[0003] The hard chrome coating is another common inorganic protective coating. Hard chromium coatings are applied in an electrolytic deposition process. However, electrolytic deposition processes require chemicals that are unstable, toxic, corrosive and harmful to the environment. The use of chemicals in the most legal systems. Personal protective equipment and appropriate installations to prevent contamination are considered mandatory.

[0004] Copper is most often used as pure, unalloyed metal. For example, copper tubing and pipes are used to transport potable water to homes. However, copper will corrode over time, and is a copper formation.

[0005] Organic (ie carbon-based) coatings, such as conventional inks, may also be used to protect surfaces chrome-free metal surfaces. However, organic coatings may deteriorate into high-pressure film-forming properties. As a result, the organic coatings may lose their protective properties.

Summary of the invention

which contains a silicon from a hardened silicon-containing liquid element. The protective coating, for example, beneath. The metal element may be made of iron, aluminum, titanium, copper, nickel, and alloys of all metals.

[0007] The silicon-free liquid containing the silicon-free composition is silicon-free. The liquid composition can be heated, for example, in argon, a metal silicide.

[0008] Essentially a chromium-free, silicon-noticed protective coating, according to elevated temperatures well above room temperature. Heat resistance will be competitive, for example, conventional and carbon based paints.

[0009] The chromium coatings and hard chromium coatings, in addition to the other coatings of conventional coatings. The protective coating of the present invention. The protective coating of the present invention is also a metal alloy.

[0010] These and other advantages are included.

Brief Description of the Drawings. Details of the invention. to explain the principles of the invention.

Fig. 1 is a perspective view of a metal element ;

Fig. 2 shows a schematic cross-sectional view of a part of the metal element of Fig. 1 which comprises a silicon-containing layer;

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Fig. 2A is a schematic cross-sectional view similar to Fig. 2 in which a silicon-introducing layer is a metal element; and Fig. 3 shows a schematic cross-sectional view similar to Fig. 2 after converting the silicon-in- dicating layer into a protective coating.

Detailed description of the chromium-free, silicon-introducing layer. 12 chromium-free of metal element 10. The metal member 10, which contains any metal, including but not limited to, iron, aluminum, titanium, copper, nickel and alloys of each other, including mild steel and stainless steel. The metal may also include some non-metallic components. However, the layer 12 and the substrate.

[0013] Essentially a chromium-free, silicon-containing layer 12 is made of a silicon-free flowable com- partment (eg, a liquid composition, solution or suspension) B (Fig 1), as if it were painted, by spraying in a controlled manner or by immersion in a bath (not shown). The unhardened fluid composition is then cured at low temperature to be able to cope with air-drying with optional heating. The curing temperature of the silicon-containing layer is significantly lower than 400 ° F (204.44 ° C). Eg,

Prior to the application of the chromium-free, silicon-including layer 12, the surface can be purified of all impurities. A degreasing agent such as acetone, sodium hydroxide (NaOH) or potassium hydroxide (KOH) 14 may be used for the surface of the cured layer 12 to the surface. Before applying the layer 12 to the surface.

[0015] A specific liquid or composition is a form of liquid silane. Silanes suitable for use in the present invention may include mono-, bis- or trifunctional trialkoxysilane. The silane can be a bi-functional trialkoxilil group, preferably trimethoxy or triethoxysilyl groups. Amine silanes may even be used, although thiosilanes may not be desirable because of the sulfur contained therein. Bifunctional silane compounds are also known in the present invention as bis (triethoxysilyl) ethane and bis (trimethoxysilyl) methane. In the group of molecules, the bridging group has the alkyl group. Additional commercially available silanes include, but are not limited to:

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1,2-bis (tetramethyldisanoxyanyl) ethane 1,9-bis (triethoxysilyl) nonane bis (triethoxysilyl) acetate bis (trimethoxysilyl) ethane

1,3-bis (trimethylsiloxy) -1, 3-dimethyldisiloxane bis (trimethylsiloxy) ethylsilane bis (trimethylsiloxy) methylsilane

Al-501 available from AG Chemetall (Frankfurt, Germany) [0016] The silane can be pure, in aqueous solution or diluted in a solution with an alcohol / alcohol solvent. 1% to 2% by volume. up to about 30% vol. deionized water, with the remainder being a monohydrate alcohol, such as methanol, ethanol, n- or iso-propanol, or the like. Ethanol and methanol are preferred monohydric alcohols. The solvent is combined with a silane and glacial acetic acid to preferably set a pH around 4-6. The concentration of silane in the solution. Typically, the solution will contain from 1% to about 20% silane, which can be measured by volume or by weight.

<RTI ID = 0.0> 2 </ RTI> <RTI ID = 0.0> Tis </ RTI> 1,2 bis (triethoxysilyl) ethane or BTSM 1,2 bis (trimethoxysilyl) methane. To make a silane solution, pH 5, then in denatured alcohol and glacial acetic acid. The silane concentration is 1% to 10% by volume, and preferably about 5% by volume. This silane solution quickly forms a silicon-containing layer 12, which must have a more protective coating. 16.

[0018] A normally applied liquid composition which, after curing, forms a silicon-containing layer 12, is applied in an amount of 0.01 g / cm ² to about 2.0 g / cm ²> . Multiple layers of the liquid composition may be applied; each layer is dried and heated to the next layer. The term "silicon-containing layer 12" is used for the composition of the composition. The silicon-including layer 12 may have a thickness of about 300 nm in the cured state.

The silicon-containing layer 12 to a temperature 12 to a chromium-free, silicon-laced protective coating layer 12 is applied. Typically, the transformation temperature is a temperature of 400 ° F (204.44 ° C) is about 70 percent of the melting point of the chromium-free metal element the transformation into the protective coating 16 will depend on the composition of the metal element 10 and the specific composition.

The protective layer 16 is purely free of chromium content.

[0020] A eutectic or a specific pre-requisite for the metal element 10. The eutectic has a different melting point than any of its constituents . The appropriate ratio of silicon is to obtain eutectic point in the phase diagram. The eutectic point is the eutectic of the metal element (s) constituting the silicon alloy. .

[0021] Essentially the chromium-free silicon layer 12 is heated in a non-oxidizing atmosphere 16. Transformation of a chromium-free chromium-free layer 12 into a substantially chromium-free, silicon -aining coating The protective element can be used as a metal element. However, a particular heating method may be selected based on the element 10 and the available heating options. The heated casing is heated. 12 sufficient to cause a transformation. C The into The 12 The 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12. The silicon-containing layer 12 to a protective coating 16.

[0022] A suitable heated environment or housing can provide, for example, heating tunnels, used in powder coating apparatuses (not shown). In particular, this is a component of the preparation of protective coating .

[0023] Essentially the chromium-free silicon layer 12 is heated in a non-oxidizing atmosphere, as is a chromium-free protective coating 16, such as silicide, which contains silicon from the layer 12 and an amount of one or more components the material constituting the metal element 10. The non-oxidizing ambient atmosphere may be a depleted atmosphere.

In an alternative embodiment of the invention, the essentially chromium-free protective layer 12 soluble in a particular silane solution, although additives containing sulfur ligands and / or oxygen ligands may be disadvantageous. If the doping material is, for example, yttrium, the corresponding yttrium compounds include, but are not limited to, yttrium halides such as yttrium, yttrium, yttrium and yttrium fluorides. Other suitable yttrium compounds include, but are not limited to, yttrium acetate, yttrium-2-ethylhexanoate, yttrium perchlorate (eg 40 wt.% In water),

Yttrium nitrate, yttrium isopropoxide, yttrium isopropoxylate (eg, 25% by weight in toluene), yttrium butoxide (eg, 0.5M in toluene), yttrium trifluoroacetate hydrate, yttrium and tris oxalate hydrate (eg 2,2,6,6-tetramethyl) -3,5-heptanedioneate) yttrium (III). If the doping material is, for example, hafnium, suitable hafnium compounds include, but are not limited to, hafnium halides, such as hafnium chloride, hafnium bromide, hafnium iodide and hafnium fluoride. Other suitable hafnium compounds include, but not limited to, any hafnium compound with an organic ligand, such as hafnium tert-butoxide and hafnium nitrates. Acceptable hafnium compounds, however, do not include compounds with either sulfur ligands or with oxide ligands. These and other compounds of yttrium and hafnium are commercially available, eg, from Sigma-Aldrich (St.

In this way, it is possible to create a solution with a silane solution. Before combining, the amount of doping agent is added to the protective chromium-free layer of silicon 12 and then in the protective coating 16. Typically, a single additive or doped compound will combine with the silane to form a flowable composition. which is applied as a layer 14.

With reference to Fig. 2A, the smallest chromium-free silicon-introducing layer 12 may be applied to the substrate. . The existing coating 18 is a form of protective coating 16.

With reference to Fig. 3, a detailed view of a chromium-free metallic element 10 and so chromium-free protective coating 16 is shown. The metal element 10 has a protective coating. 16 protects the underlying material. the metal substrate 12 before, for example, oxidation and corrosion.

[0028] The real chromium-free protective coating 16 is a metal layer 15 and a substrate metal 15 In the case of the diffusion zone, the substrate 15 into the protective coating. 16 that ultimately give the coating 16 favorable protective qualities.

[0029] The invention further contemplates that the liquid chromium-free metal member 10 is a form of chromium-free silicon-exposed protective coating. . On 16 on 16 on 16 on 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 on 16. On 16 on 16 on 16 on 16 on 16 on 16 on 16 on 16 on 16 on 16. 16 on these purpose.

[0030] As an example, not as free of chromium, the silicon-introducing layer 12 can be applied to a metal element 10 made of hot and cold water, above 400 ° F (204.44 ° C) which is sufficient to form a composition of layer 12. Although

We do not want to be limited by theory, it is believed coating reduces the oxidation of the substrate 15.

[0031] As another example, substantially chromium-free, silicon-introducing the layer 12 can be applied to the metal body 10 to its final dimensions. When it is heated, 400 ° C (752 ° F) but above 400 ° F (204.4 ° C) in a non-oxidizing environment, a silicon-contained protective coating 16 is produced in which silicon is incorporated into the metal. - copper as diffusion zone. 22 with optional additional layer.

[0032] As yet another example, substantially free of chromium, the silicon-containing layer 12 can be applied to a metal element 10 made of steel. The application of a thin silane layer, followed by heating to below 770 ° C (1418 ° F), but above 400 ° F (204.4 ° C) in the nonoxidating environment of the coating 16, which may be an iron silicide, which improves Corrosion resistance. The solubility of silicon in iron is less than four (4) percent by weight. In very dilute solutions less than 0.4 percent by weight silicon, silicon can replace carbon steel.

[0033] In another implementation not based on the invention, the existing layer 18 (Fig. 2A) may be a chromium-free metal element 10 before handling substantially chromium-free, silicon-containing material. layer 12. The silicon-introducing layer 12 is heated to 800 ° C (1472 ° F) above 400 ° F in an environment of 16 the element 10 or the layer 12, but, instead, from layer 18.

[0034] As yet another example, the substantially chromium-free silicon-containing layer 12 may be applied to a metal member; 44 ° C) in a non-oxidizing environment 16 of silicide. The solubility of silicon in aluminum is limited to one (1) percent by weight. up to 1.5 percent by weight at a eutectic temperature of 577 ° C (1071 ° F).

[0035] The protective coating can be used as an element of the metal element.

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