Abstract: Disclosed is a process in which a phosphate layer is formed on a metal surface in preparation for the subsequent application of a vitreous enamel coating, wherein a phosphating solution is used which contains essentially nickel and/or cobalt as a layer-forming cation in amounts of 0.5 to 3 g/l as well as5 to 20 g/l phosphate (calculated as P.sub.2 O.sub.5),0.1 to 0.5 g/l molybdate (calculated as MoO.sub.3),0.2 to 2 g/l fluoride (calculated as F),1 to 10 g/l nitrate (calculated as NO.sub.3),and optionally also 0.1 to 5 g/l urea.It is particularly desirable to use essentially zinc-free phosphating solutions at temperatures preferably of 60.degree. to 70.degree. C. for 2 to 12 minutes to form a phosphate layer having a coating weight of 1.0 to 2.0 g/m.sup.2.
Type:
Grant
Filed:
August 22, 1995
Date of Patent:
November 18, 1997
Assignee:
Metallgesellschaft Aktiengesellschaft
Inventors:
Margit Fleischhacker-Jeworrek, Dieter Jentsch, Klaus Wittel
Abstract: Quaternary ammonium salt having at least one alkyl group of 10 to 20 in carbon number is added to a chemical conversion solution to be at least 20 ppm in concentration, and a chemical conversion coating is formed on a surface of a metal can with this chemical conversion solution. After the chemical conversion coating is formed on the surface of the metal can with the chemical conversion solution, a surface treatment solution containing quaternary ammonium salt having at least one alkyl group of 10 to 20 in carbon number is applied to the surface of the metal can provided with the chemical conversion coating.
Abstract: Metallic forms of gold and other precious metals can be dissolved and transported (mined) using an aqueous sulfide-bearing leach solution. Maximum sulfur fugacities are achieved in sulfide-bearing solutions under approximately neutral pH and relatively reducing conditions. The optimum chemical conditions are achieved specifically by heating an aqueous sulfide solution such as NaHS, Na.sub.2 S, H.sub.2 S, (NH).sub.4 S, or other suitable forms to temperatures of at least about 100.degree. C. in the presence of excess elemental sulfur. The sulfide dissociates in the solution to form aqueous sulfide species including polysulfide and HS.sup.- which lixivate gold and other precious metals.
Type:
Grant
Filed:
June 14, 1996
Date of Patent:
November 4, 1997
Assignee:
The United States of America as represented by the Secretary of the Interior
Inventors:
Drummond Earley, III, Michael E. Berndt
Abstract: This invention relates to a non-electrolytic process for applying a paint adherent and corrosion resistant coating of magnesium phosphate and magnesium fluoride to a product formed from a magnesium alloy. The process includes immersing the magnesium alloy product in a solution having phosphate and fluoride ions. The process may further include controlling a pH level of the solution, providing the solution in which the magnesium alloy product is immersed with a concentration by weight of sodium bifluoride, and controlling the solution at a certain temperature, while the magnesium alloy product is immersed for a determined period of time.
Abstract: A process for the production of a heat- and corrosion-resistant porous metal body which is made of a metal or whose surface layer is made of a metal, in which the porous metal body can be alloyed with chromium or a combination of chromium and aluminum uniformly throughout the entire thereof by adjusting the alloy composition in the following manner, i.e., (A) heat-treating the porous metal body in a mixed gas comprising a gas, generated by heating a powdered mixture comprising chromium or its compound and NH.sub.4 Cl at 950.degree. to 1100.degree. C., and a diluent reducing gas at 800.degree. to 1100.degree. C., or (B) heat-treating the porous metal body in a mixed gas comprising a gas, generated by heating a powdered mixture comprising aluminum or its compound, chromium or its compound and NH.sub.4 X, wherein X is I, F, Cl or Br, at a weight ratio of the chromium or its compound to the aluminum or its compound of 10 to 80 in terms of Cr and Al respectively at 950.degree. to 1100.degree. C.
Abstract: A process for producing a black oxide coating on an aluminum or aluminum alloy component in which the process entails a single treatment step with a novel solution to rapidly produce the desired black oxide coating. The process includes cleaning the surface to be coated and then, without first undergoing anodization, treating the surface with a solution that develops a black oxide on the surface. The reactive component of the solution comprises distilled water containing chlorides, sulfates and bicarbonates of sodium salts. The remainder of the solution includes a catalyst and a substance for maintaining the pH of the solution at a level sufficient to promote the reaction between the surface of the aluminum alloy and the reactive constituents.
Type:
Grant
Filed:
September 23, 1996
Date of Patent:
September 16, 1997
Assignee:
General Motors Corporation
Inventors:
Ravi Rungta, Robert Roy Ahrens, Mingguang Zhu
Abstract: A rinse solution for the treatment of conversion-coated metal substrates for improving the adhesion and corrosion resistance of siccative coatings, comprising an aqueous solution of a Group IVA metal ion, namely, zirconium, titanium, hafnium, and mixtures thereof, and a phenol polymer, with the pH of the total solution about 3.5 to 5.1. A method for treating such materials by applying the rinse solution to the substrate.
Abstract: The present invention is directed to provide a stainless steel having by far higher corrosion resistance than those of the prior art and a method of forming an oxide passivation film having a chromium oxide layer on the surface thereof.(1) An oxide passivation film having a layer consisting of a chromium oxide as a principal component in a thickness of at least 20 .ANG. on the outermost surface side is formed on the surface. (2) A machining strain layer composing fine crystals is formed on the surface of a stainless steel base, baking is then carried out in an inert gas to remove moisture from the surface of the stainless steel, and heat-treatment is carried out at 450.degree. to 600.degree. C. in an atmosphere of a mixed gas consisting of the inert gas and 500 ppb to 2% H.sub.2 O gas (or 4 ppm to 1% of oxygen gas).
Abstract: The composition of a non-chrome post-rinse composition for treating phosphated metal substrates is disclosed. The composition comprises the reaction product of an epoxy-functional material containing at least two epoxy groups; and an alkanolamine, or a mixture of alkanolamines. The composition further comprises a group IV-B metal ion, or a mixture of group IV-B metal ions. Also provided is a non-chrome post-rinse concentrate; a process for treating a phosphated metal substrate comprising contacting said phosphated metal substrate with the non-chrome post-rinse composition described above; and the coated article prepared by this process.
Type:
Grant
Filed:
October 20, 1995
Date of Patent:
August 5, 1997
Assignee:
PPG Industries, Inc.
Inventors:
Mark W. McMillen, Richard M. Nugent, Jr.
Abstract: An aqueous phosphoric bonding solution and coating composition slurry which are environmentally friendly in that they are generally free of molybdate or chromium. Yet the solution is stable with respect to inorganic metal particles, especially aluminum which are admixed to the bonding solution for the preparation of the coating slurry. The metal coated parts and the method of coating the parts with the coating composition are also described. The parts have very satisfactory properties.
Abstract: A Zn--Mg binary coating layer formed on a steel sheet has the tri-layered structure that the first sublayer composed of a Zn--Mg alloy having Mg concentration of 0.5 wt. % or less, the second sublayer composed of a Zn--Mg alloy having Mg concentration of 7 wt. % or more and the third sublayer composed of a Zn--Mg alloy having Mg concentration of 0.5 wt. % or less are successively laminated. The coating layer may have the penta-layered structure wherein sublayers composed of a Zn--Mg alloy having Mg concentration of 2-7 wt. % are additionally interposed between the high-Mg and low-Mg sublayers. A Zn--Fe or Zn--Fe--Mg alloy layer may be formed at the boundary between the substrate steel and the coating layer. The adhesion ratio of the first sublayer to the top sublayer is preferably 1.2 or more, while the high-Mg sublayer is preferably conditioned to the mixed structure of a Zn.sub.2 Mg phase with a Mg-dissolved Zn phase.
Abstract: In this method, aluminization is performed by using thermochemical treatment, and an aluminum donor piece (6) based on metallic aluminum is placed in the vicinity of the surface to be treated (2), prior to said treatment. Preferably, said piece is provided with a thin metal coating (10) that withstands the treatment temperature. The invention is particularly applicable to protecting cooling channels in the blades of a gas turbine.
Abstract: The present invention produces a highly corrosion-resistant, highly rust-inhibiting, and strongly paint-adherent conversion coating on the surface of magnesium-containing metals, and does so rapidly and at relatively low temperatures, using a substantially chromium-free conversion treatment bath.
Type:
Grant
Filed:
April 29, 1996
Date of Patent:
July 8, 1997
Assignee:
Henkel Corporation
Inventors:
Sadao Ishizaki, Masahiko Nishida, Yokichi Sato
Abstract: A strip of highly reflective aluminum protected by a conversion coating and a light-permeable fluoropolymer coating which is non-adhesively interstitially mechanically bonded to the microscopic irregularities of the conversion coated surface. The highly reflective strip may be substituted for polished stainless steel and/or bi-metal and used under aggressive conditions for a prolonged period without deleteriously affecting the initial D/I (distinctness of reflected image) of the shaped strip. The strip of arbitrary length may be shaped in rolling dies so that at least a portion of the strip has a radius of less than 10 mm without damaging or separating the fluoropolymer coating. The specific steps of the claimed process require starting with a bright-rolled clean strip which is conversion coated to carry a thin metal compound coating. The reflective conversion coated surface is coated with the fluoropolymer while maintaining at least 80% D/I.
Abstract: The present invention comprises an improved organic composite-plated steel plate which is obtained by applying a thermosetting resin to a chromate-coated alloy-plated steel plate and curing this, wherein, various aqueous resin compositions having the form of basic coating film formation components, such as, for example, aqueous vinyl modified epoxy ester resins, or aqueous vinyl modified epoxy ester resin/blocked isocyanate compound-types, or aqueous vinyl modified epoxy ester resin/blocked isocyanate compounds/colloidal silica-types, are used as the thermosetting resin described above.
Type:
Grant
Filed:
March 1, 1995
Date of Patent:
June 10, 1997
Assignees:
Dainippon Ink and Chemicals, Inc., Nippon Steel Corporation
Abstract: The surface of an aluminide is treated to make it less chemically reactive. In particular, this treatment inhibits oxidation of the aluminide at high temperatures. According to the invention, one coats the aluminide with a solution that containing phosphoric or phosphorous acid, and then one heats the aluminide, so as to calcine the coating. The phosphoric or phosphorous acid reacts with the aluminide to form a surface that resists oxidation. One can use this process to coat the blades of a gas turbine, or to coat other aluminide structures intended for use in high-temperature environments.
Abstract: A method for treating the surface of aluminum alloys hang a relatively high copper content is provided which includes the steps of removing substantially all of the copper from the surface, contacting the surface with a first solution containing cerium, electrically charging the surface while contacting the surface in an aqueous molybdate solution, and contacting the surface with a second solution containing cerium. The copper is substantially removed from the surface in the first step either by (i) contacting the surface with an acidic chromate solution or by (ii) contacting the surface with an acidic nitrate solution while subjecting the surface to an electric potential. The corrosion-resistant surface resulting from the invention is excellent, consistent and uniform throughout the surface. Surfaces treated by the invention may often be certified for use in salt-water services.
Type:
Grant
Filed:
May 22, 1995
Date of Patent:
June 3, 1997
Assignee:
University of Southern California
Inventors:
Florian B. Mansfeld, You Wang, Simon H. Lin
Abstract: A process is described for reducing the metal exposure rating of metal surfaces which subsequently are coated with a siccative coating which comprises contacting said metal surface with an aqueous composition comprising a polyethylene selected from the group consisting of ethylene homopolymers, oxidized ethylene homopolymers, ethylene/acrylate copolymers, and terpolymers containing ethylene, acrylates, and esters. A process is also described for improving the mobility of formed metal surfaces and reducing the metal exposure rating of the surfaces which subsequently are coated with a siccative coating.
Abstract: A coating preparation for pretreating metals comprises an acrylic acid or a derivative thereof and barium hydroxide in a proportion by weight of 1:0.08-0.30, as well as chromium compounds, the remainder being conventional additives and water. The amount of acrylic acid or derivative thereof is preferably 2-6% by weight. The amount of chromic acid in the chromium compounds in the coating preparation depends on the type of the metal substrate to be treated. Such a preparation combines, in a single preparation, the desired properties for conversion of the metal and adhesion, which means that instead of 2 separate layers, 1 layer is sufficient.
Abstract: A copper alloy plumbing fixture containing interdispersed lead particles coated noncontinuously on a water contact surface to resist the leaching of lead into potable water systems. The leach resistant fixture is prepared by immersing conventional copper alloys in a bismuth nitrate solution, selectively and noncontinuously coating the lead dispersoid particles on the water contact surface with bismuth. Tin may be substituted for bismuth to obtain similar results.
Type:
Grant
Filed:
February 14, 1996
Date of Patent:
May 27, 1997
Assignee:
Technology Management Advisors LLC
Inventors:
Enzo L. Coltrinari, Jerome P. Downey, Wayne C. Hazen, Paul B. Queneau