Abstract: The present subject matter relates to Nickel-free (Ni-free) sealing of anodized metal substrates. In an example mentation of the present subject matter, an anodized metal substrate is disposed with a first layer of a Ni-free sealing material over a surface of the anodized metal substrate. Further, a second layer of a second sealing material is disposed atop the first layer to sandwich the first layer of Ni-free sealing material between the surface of the anodized metal substrate and the second layer, to form a sealed metal substrate.

Abstract: A laminate structure and method of forming is provided. The laminate structure includes a first metal sheet having a first thickness, a second metal sheet having a second thickness, and an adhesive core having an adhesive thickness. The adhesive core is disposed between and bonded to the first and second metal sheets. The first and second metal sheets are made of an aluminum based material and the adhesive core is made of an adhesive material also described as a viscoelastic adhesive material. The laminate structure is configured such that a ratio of the sum of the first and second thickness to the adhesive thickness is greater than either to one (8:1). The laminate structure including the viscoelastic adhesive core is characterized by a composite loss factor at 1,000 Hertz which is continuously greater than 0.1 within a temperature range of 25 degrees Celsius to 50 degrees Celsius.

Abstract: An assembly comprises a mounting ring for a rotating rectifier assembly (RRA) having a pin bore defined in the mounting ring oriented in an axial direction and at least one contact band seated in a the pin bore of the mounting ring for mounting a direct current (DC) pin to the mounting ring. A method comprises forming a mounting ring for a rotating rectifier assembly (RRA), including forming a pin bore in the mounting ring oriented in an axial direction, and installing at least one contact band into a the pin bore of the mounting ring.

Abstract: A heat exchanger includes a bag-like outer packaging material. A heat medium flows into an inside of the outer packaging material. An inner core material is arranged in the inside of the outer packaging material. The outer packaging material has an outer packaging laminate material including a metal heat transfer layer and a resin thermal fusion layer on a surface side of the heat transfer layer. The outer packaging laminate materials form a bag shape by integrally joining the thermal fusion layers along the peripheral edge portions. The inner core material includes the inner core laminate material with a metal heat transfer layer and resin thermal fusion layers on surface sides of the heat transfer layer. The thermal fusion layers of a concave portion bottom and a convex portion top of the inner core material and the thermal fusion layers of the outer packaging laminate material are integrally joined.

Abstract: The present invention relates to an additive composition for scavenging hydrogen sulfide in hydrocarbons, wherein said additive composition comprises a combination of (a) glyoxal and (b) at least one aliphatic tertiary amine or oxide treated derivative thereof, or a mixture of the aliphatic tertiary amine and the oxide treated derivative thereof. In one embodiment it also relates to a method for scavenging hydrogen sulfide in hydrocarbons, and in another embodiment it relates to a method of using an additive composition of the present invention for scavenging hydrogen sulfide in hydrocarbons. In yet another embodiment it relates to a composition for scavenging hydrogen sulfide in hydrocarbons comprising (A) a hydrocarbon and (B) a hydrogen sulfide scavenging additive composition of the present invention.

Abstract: Described herein is a method for phosphating of a metallic surface, wherein a metallic surface, optionally after cleaning and/or activation, is first treated with an acidic, aqueous, substantially nickel-free phosphating composition that includes zinc ions, manganese ions, iron(III) ions and phosphate ions, and is thereafter optionally rinsed and/or dried. Also described herein are a corresponding phosphating composition and a correspondingly phosphate-coated metallic surface.

Abstract: A method for manufacturing a gas sensor may be provided, the method comprising the steps of: preparing a porous base substrate; providing, on the porous base substarte, a source solution having graphene dispersed in a base solvent; manufacturing a graphene-impregnated base substrate by means of a driving process; and forming a first electrode and a second electrode on the graphene-impregnated base substrate.

Abstract: A method of screening or testing a sample is disclosed that comprises ionising a native human hemoglobin sample to generate parent or precursor ions, subjecting the parent or precursor ions to Electron Transfer Dissociation fragmentation so as to generate a plurality of fragment ions, mass analysing the fragment ions and determining whether or not the fragment ions include fragment ions which are indicative of a variant of hemoglobin.

Abstract: Disclosed are pretreatment compositions and associated methods for treating metal substrates with pretreatment compositions, including ferrous substrates, such as cold rolled steel and electrogalvanized steel. The pretreatment composition includes: a Group IIIB and/or IVB metal; free fluoride; and lithium. The methods include contacting the metal substrates with the pretreatment composition.

Abstract: Provided are an anodic oxide film of an anodic oxide film of an aluminum-based material and a method for performing a sealing treatment on the anodic oxide film which can achieve both high corrosion resistance and high repairing ability. A method may comprise applying direct current electrolysis to an aluminum-based material to form a second anodic oxide film. After which, an AC-DC superimposition electrolysis may be applied to the aluminum-based material to further form a first anodic oxide film. A sealing treatment may then be performed on the first and second anodic oxide films with a solution containing lithium ions.

Abstract: A heat and moisture exchanger includes: a heat and moisture exchanger material formed by coiling a strip-shaped porous body, the porous body having a plurality of slits formed therein that are arranged along the lengthwise direction, into a spirally-wound shape with the slits facing radially outwardly; and a housing that accommodates the heat and moisture exchanger material. Such a structure for an HME makes it possible to reduce pressure loss and improve moisture retention capabilities by means of a relatively simple structure, thereby allowing the inexpensive provision of an HME that lowers the burden on a patient.

Abstract: The present disclosure relates to a method of incorporating lithium into a coating. One may supply a substrate having a coating containing aluminum ions and immersing the substrate including the coating containing aluminum ions in a water-soluble diketone including lithium for exchange where the ketone carbonyls are separated by at least one carbon atom. This may then be followed by exchanging a portion of the aluminum ions with lithium ions from the diketone solution. Such coatings may have improved chemical resistance.

Abstract: Disclosed herein are a printed circuit board and a method for manufacturing the same. The printed circuit board includes: a base substrate having a metal pattern for a circuit; and a surface roughness provided on the metal pattern, wherein the surface roughness has a first surface roughness in an anchor structure and a second surface roughness having a black oxide layer in a granular structure formed on the first surface roughness.

Abstract: Metal products having improved properties and processes for preparing the metal products are provided. The present disclosure provides for a metal product comprising a metal surface, an oxide layer and a glass layer. The glass layer is provided by coating a stable aqueous silicate or borosilicate solution onto the metal surface and curing the aqueous solution to produce a glass layer. The metal products have surface characteristics that outperform all anodized metal surfaces.

Abstract: A solution for removing an aluminum oxide film from an aluminum or aluminum alloy surface, which includes a salt or oxide of a metal capable of substituting aluminum, a solubilizing agent for ions of the metal, and an alkali, and which has a pH of 10 to 13.5. The removing solution makes it possible to form a film of the metal derived from the metal salt or oxide contained in the removing solution by dissolving away the oxide film from the aluminum or aluminum alloy surface at a low temperature and a high speed while restraining, as securely as possible, erosion of the aluminum or aluminum alloy surface. The removing solution ensures that even in the case where the thickness of the aluminum or aluminum alloy basis material is very small, the aluminum or aluminum alloy surface can be activated while assuredly leaving the aluminum or aluminum alloy basis material.

Abstract: In various embodiments, a method of processing a contact pad may include providing a contact pad, a topmost layer of the contact pad containing aluminum or an aluminum alloy, at least part of the topmost layer of the contact pad being exposed; subjecting the contact pad to a thermally activated atmosphere containing water or reactive components of water.

Abstract: A process for producing a ceramic implant which is structured on the surface at least in the region in contact with bone and/or tissue is described. The process is characterized in that the ceramic implant after shaping and sintering is, in the region to be structured, I. reduced to the corresponding metal on the surface; II. the essentially metallic surface is subsequently subjected to a structuring surface treatment; III. the structure surface is oxidized. Furthermore, implants which have been provided with a topological structure on the surface by means of this process are described.

Abstract: A method for protecting silver and silver alloy surfaces against tarnishing, characterized by initially subjecting the surface to be treated to cleaning pre-treatment in organic solvents; immersing the cleaned surface in an acid solution able to ensure formation of a thin layer of silver oxide; immersing the oxidized surface in a solution of at least one thiol of formula CH3(CH2)nSH where n is between 10 and 16; and chemically reacting the molecules of said thiol with the previously oxidized silver surface, in an environment containing water vapor at a temperature of at least 50° C.

Abstract: The invention concerns a process for preparing a hybrid organic-inorganic material (HOIM) with phosphorus-containing bridges between the surface of an inorganic substrate containing an element M and one or more organic groups of the covalent M-O-P-R type, said process using, as a precursor for said organic group or groups, at least one organophosphorus acid halide with formula RxP(O)Xy in which x=1 or 2, y=3?x, X being a halogen and R designating at least one organic alkyl, aryl or aryl-alkyl group. Non-exhaustive applications for the hybrid organic-inorganic material obtained by the process of the invention are in the fields of anti-corrosion, lubrication, microelectronics, nanotechnologies, composite materials, heterogeneous catalysis, supported catalysis, depollution and biomedical applications.

Abstract: A baking finishing formula comprise metallic zinc, metallic nickel, metallic aluminum, polyethylene glycol, a silane, fluoride-containing surfactants, corrosion inhibitors and a mixed-type additive.

Abstract: Disclosed is a composite black oxide particle which is composed of oxide of cobalt, copper and manganese. The copper/cobalt molar ratio is 0.1-0.5, and the manganese/cobalt molar ratio is 0.2-1.0. The composite black oxide particle further contains silicon, and the silicon content to the total oxide particle is 0.1-3 mass %. The surface of the composite black oxide particle is coated with aluminum oxide. The Al content in the surface coating to the entire particle is 0.05-3 mass %.

Abstract: A conversion coating composition for coating a metal substrate is provided which imparts corrosion resistance to the underlying metal substrate. The conversion coating composition comprises an aqueous carrier and first and second rare earth element salts. A complete coating system employing the conversion coating composition is also provided as well as methods for conversion coating a metal substrate with the rare earth element conversion coating compositions of the present invention.

Abstract: Anodic oxidation coatings are selectively removed from anodic oxidation-treated aluminum or aluminum alloy members by immersion in a solution composition. By using a remover composition characterized by containing phosphoric acid and a molybdate salt, it is possible to selectively remove the anodic oxidation coatings from the aluminum or aluminum alloy members without substantially dissolving the basis metal aluminum or aluminum alloy.

Abstract: The surface treatment agent for copper and copper alloys contains hydrogen peroxide, a mineral acid, an azole compound, silver ion and a halide ion. The surface treatment agent for copper and copper alloys is useful in the production of printed wiring boards in electronics industry. The surface treatment agent roughens the surface of copper and copper alloys. Particularly, the surface treatment agent can form a uniform and undulation-free roughened surface on copper-clad substrates having plated mirror surface, this having been difficult in conventional techniques, thereby significantly improving the adhesion to etching resists, solder resists, in addition, to prepregs and a resin for mounting electronic parts.

Abstract: A method for inhibiting corrosion, e.g., pitting corrosion, of alloys is provided. Particularly, the method comprises contacting at least a portion of a surface of the alloy with an aqueous solution comprising a salt of one or more rare earth elements selected from the group consisting of yttrium, gadolinium, cerium, europium, terbium, samarium, neodymium, praseodymium, lanthanum, holmium, ytterbium, dysprosium and erbium; and establishing a voltage differential between an anode comprising the alloy and a cathode in the solution at an effective level and for a sufficient period of time wherein a rare earth element oxide-containing coating is formed on the surface of the alloy to inhibit corrosion thereof.

Abstract: A method for forming a zinc oxalate coating on the surface of a strip or sheet of metal covered with a zinc or zinc alloy coating other than zinc/iron coatings, with the aid of an aqueous solution consisting of oxalic acid having a concentration of between 5.10?3 and 0.1 mole/l, and at least one compound and/or ion of an oxidant zinc metal having a concentration of between 10?6 and 10?2 mole/l, and possibly a wetting agent. The inventive method enables sheet metal to be treated at very high speeds without using large amounts of oxidant. It facilitates management of treatment baths. The invention can be used in the lubrication of sheet metal, especially for die stamping.

Abstract: This invention is a method for forming a chemical conversion coating on ferrous metal substrates, the chemical solutions used in the coating and the articles coated thereby. By modifying and combining the features of two existing, but heretofore unrelated, coating technologies, a hybrid conversion coating is formed. Specifically, a molecular iron/oxygen-enriched intermediate coating, such as a dicarboxylate or phosphate, is applied to a ferrous substrate by a first oxidation. The intermediate coating pre-conditions the substrate to form a surface rich in molecular iron and oxygen in a form easily accessible for further reaction. This oxidation procedure is followed by a coloring procedure using a heated (about 120-220 F) oxidizing solution containing alkali metal hydroxide, alkali metal nitrate, alkali metal nitrite or mixtures thereof, which reacts with the iron and oxygen enriched intermediate coating to form magnetite (Fe3O4).

Abstract: This invention includes improvements to a method for forming a chemical conversion coating on ferrous metal substrates, to the chemical solutions used in the coating and to the articles coated thereby. A first oxidation applies a molecular iron/oxygen-enriched intermediate coating, such as a dicarboxylate or phosphate, to a ferrous substrate. A coloring procedure (a second oxidation) follows the first oxidation procedure, using a heated oxidizing solution that reacts with the iron and oxygen enriched intermediate coating to form magnetite (Fe3O4). The result is the formation of a brown or black finish. An appropriate rust preventive topcoat may seal the substrate. The finish affords protection, a degree of lubricity to aid assembly, break-in of sliding surfaces, provides anti-galling protection and an adherent base for paint finishes.

Abstract: A chromium- and nitrogen-free brightening and passivating treatment for metal surfaces, particularly iron and steel, comprises: at least one acid; at least one substance containing a peroxy moiety; and at least one organic substance selected from the group consisting of; molecules that contain both at least one ether moiety and at least one hydroxyl moiety; molecules that contain at least two ether moieties; and molecules that contain in each molecule both at least one ether moiety and one nitrogen atom that is covalently bonded to at least three carbon atoms. Preferably part of the acid contains phosphorus, which has been found to act synergistically with the organic substance to stabilize peroxy compounds against decomposition, particularly in the presence of metal ions.

Abstract: A corrosion resistant component of semiconductor processing equipment such as a plasma chamber comprises a cerium oxide containing ceramic material as an outermost surface of the component. The cerium oxide containing ceramic material comprises one or more cerium oxides as the single largest constituent thereof. The component can be made entirely of the cerium oxide containing ceramic material or, alternatively, the cerium oxide containing ceramic can be provided as a layer on a substrate such as aluminum or an aluminum alloy, a ceramic material, stainless steel, or a refractory metal. The cerium oxide containing ceramic layer can be provided as a coating by a technique such as plasma spraying. One or more intermediate layers may be provided between the component and the cerium oxide containing ceramic coating.

Abstract: An article made of magnesium or its alloys, some or all of whose surface has a conversion coating, the conversion coating comprising MgO, Mn2O3 and MnO2 plus at least one oxide from the group consisting of vanadium, molybdenum and tungsten; and also a process for producing such an article, and its use.

Abstract: An aqueous acidic solution for forming a rare earth element containing conversion coating on the surface of a metal, said solution being chromate-free and including effective quantities of at least one rare earth element (as herein defined) containing species, an oxidant and at least one accelerator, comprising a metal selected from Groups VA and VIA of the Periodic Table.

Abstract: An aqueous acidic solution for forming a conversion coating on the surface of a metallic material, said solution containing at least one rare earth element (as herein defined) containing species, an accelerator additive selected from the group consisting of metals of Group IB, IIB, IVA, VA, VIA and VIII of the Periodic Table, a peroxidic species and at least one acid selected from the group of mineral acids, carboxylic acids, sulphonic acids and phosphonic acids, wherein said solution contains no more than 20 mg/liter each of fluoride and of phosphate, and the solution is essentially free of chromate.

Abstract: An object of the present invention is to provide a high strength Mg based alloy and a Mg based casting alloy having a good fluidity and a good mechanical property, and a molded article using the alloy. A high strength Mg based alloy, which contains, by weight, 12 to 20% of Al, 0.1 to 10% of Zn; 0.1 to 15% of Sn; and 0.05 to 1.5% of Mn.

Abstract: A method for treating a micro-roughened metal surface to improve bonding between the metal surface and a polymer material. The method involves post-treating the micro-roughened conversion coated metal surface with an aqueous wetting agent composition after having formed the micro-roughened conversion coated metal surface with an adhesion promotion composition. The method can be employed in the circuit board industry to improve bonding between layers in multilayer circuit boards.

Abstract: A method for improving the electrical conductivity of a substrate of metal, metal alloy or metal oxide comprising depositing a small or minor amount of metal or metals from Group VIIIA metals (Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt) or from Group IA metals (Cu, Ag, Au) on a substrate of metal, metal alloys and/or metal oxide from Group IVA metals (Ti, Zr, Hf), Group VA metals (V, Nb, Ta), Group VIA metals (Cr, Mo, W) and Al, Mn, Ni and Cu and then directing a high energy beam onto the substrate to cause an intermixing of the deposited material with the native oxide of the substrate metal or metal alloy. The native oxide layer is changed from electrically insulating to electrically conductive. The step of depositing can be carried out, for example, by ion beam assisted deposition, electron beam deposition, chemical vapor deposition, physical vapor deposition, plasma assisted, low pressure plasma and plasma spray deposition and the like.

Abstract: Disclosed are processes and compositions of solutions for chromate-replacement coatings for aluminum and aluminum alloys. A preferred method includes forming a boehmite coating layer that includes Al (III) ions on an aluminum surface, and applying an ionic conversion coating solution to the coating layer. The ionic conversion coating solution comprises hexavalent and trivalent ions. The trivalent ions are selected from the group consisting of Ce, Ga, Mn, Sc, Ti, Te and V. The hexavalent ions are selected from the group consisting of Mn, Mo, Se and W. It is contended that the resulting coatings provide corrosion resistance and self-healing effect in any defects present in the coatings.

Abstract: Corrosion of steel surfaces in a heat pump is inhibited by adding a rare earth metal salt to the heat pump's ammonia/water working fluid. In preferred embodiments, the rare earth metal salt includes cerium, and the steel surfaces are cerated to enhance the corrosion-inhibiting effects.

Abstract: The invention relates to a method of treating a liquid gallium or gallium alloy surface for prolonged use as a liquid mirror. The method of the invention comprises the steps of (a) contacting the surface of liquid gallium or gallium alloy with an aqueous solution of a halogenic acid to cause dissolution of any gallium oxide present on the surface, thereby obtaining an oxide-free liquid gallium or gallium alloy surface covered with a layer of the acid solution; (b) adding to the acid solution an aqueous solution of a surfactant present in an amount to form a single bimolecular layer of surfactant at an interface between the liquid gallium or gallium alloy and water; and (c) allowing a uniform passivating oxide layer to gradually form on the oxide-free liquid gallium or gallium alloy surface, the passivating oxide layer having surface irregularities smaller than 40 nm.

Abstract: A method of coating a catalyst layer on a metallic substrate includes preparing a metal oxide and binder slurry to coat onto a metal surface and forming a catalytic layer over the slurry coated surface. The slurry may be made from a binder containing, for example, fully dissolved alumina in the presence of excess nitric acid. The binder may then be mixed with a metal oxide mixture to form the metal oxide-binder slurry. The metal oxide mixture may contain aluminum oxide or partially hydrated aluminum oxide. The metal oxide-binder slurry can be used to coat the surfaces of a variety of metals such as aluminum, titanium, nickel, cobalt, chromium, iron, copper, etc., or their alloys that include brass, as well as stainless steel with or without Al as a component.

Abstract: The present invention is drawn to a method of lowering the net resistivity of an interconnect by depositing a monomer layer upon an aluminum bonding pad, the treatment thereof to cross link the monomer to form an electrically conductive polymer, and simultaneously, the substantial reduction of alumina, Al2O3, to metallic aluminum. In the method of the present invention, deposition of a monomer layer in a solvent, volatilization of the solvent, and contact with a strong oxidizer such as a potassium permanganate allows for the use of the strong oxidizer without the hindrance of having to deal with a manganese oxide husk on the surface of the aluminum bonding pad. Preferably, the chemical qualities of the monomer will include the tendency to be a reducing agent to the native oxide film of the bonding pad. By selecting a monomer that tends to reduce rather than to oxidize, the problem of thickening the native oxide film is avoided.

Abstract: The method of manufacturing a hydrogen-absorbing alloy electrode according to this invention comprises the steps of: dissolving a particle surface of said hydrogen-absorbing alloy by a surface-treatment solution; and washing the hydrogen-absorbing alloy with the particle surface dissolved using an alkaline solution at a temperature of 30° C.˜40° C. The metal ions dissolved by the surface-treatment solution can be completely washed away by the alkaline solution so that they will not be precipitated onto the surface of the hydrogen-absorbing alloy again as the hydroxide.

Abstract: An aqueous composition for sealing anodically oxidized aluminum surfaces is described. The composition contains at least one surfactant, a magnesium salt, and a cobalt(II) salt. This composition demonstrates enhanced sealant properties. A method for sealing anodically oxidized aluminum surfaces is also described. In this method, the aluminum is contacted with a composition containing at least one surfactant, a magnesium salt and a cobalt(II) salt.

Abstract: A direct displacement plating process provides a uniform, adherent coating of a relatively stable metal (e.g., nickel) on a highly reactive metal (e.g., aluminum) that is normally covered with a recalcitrant oxide layer. The displacement reaction proceeds, preferably in a nonaqueous solvent, as the oxide layer is dissolved by a fluoride activator. Halide anions are used to provide high solubility, to serve as an anhydrous source of stable metal ions, and to control the rate of the displacement reaction. A low concentration of activator species and little or no solution agitation are used to cause depletion of the activator species within pores in the surface oxide so that attack of the reactive metal substrate is minimized. Used in conjunction with electroless nickel deposition to thicken the displacement coating, this process can be used to render aluminum pads on IC chips solderable without the need for expensive masks and vacuum deposition operations.

Abstract: Method for reducing in situ the electrochemical corrosion potential and susceptibility to stress corrosion cracking of a nickel-base alloy and boiling water nuclear reactor components formed therefrom when in contact with high temperature water. The method comprises the steps of: adding a metal hydride to the high temperature water; dissociating the metal hydride in the high temperature water to form a metal and at least one hydrogen ion; and reducing the concentration of the oxidizing species by reacting the hydrogen ions with an oxidizing species, thereby reducing in situ the electrochemical corrosion potential of the nickel-base alloy. The method may further include the steps of reacting the metal with oxygen present in the high temperature water to form an insoluble oxide and incorporating the metal into the surface of the nickel-base alloy, thereby reducing the electrical conductivity of the surface of the nickel-base alloy.

Abstract: A method for producing oxidation-resistant austenitic alloys for use at temperatures below 800° C. comprising of: providing an alloy comprising, by weight %: 14-18% chromium, 15-18% nickel, 1-3% manganese, 1-2% molybdenum, 2-4% silicon, 0% aluminum and the balance being iron; heating the alloy to 800° C. for between 175-250 hours prior to use in order to form a continuous silicon oxide film and another oxide film. The method provides a means of producing stainless steels with superior oxidation resistance at temperatures above 700° C.

Abstract: The invention is a method of forming a conversion coating on an aluminum surface. According to the method, the aluminum surface is conversion coated by first treating the surface with thermal degreasing or aqueous alkaline degreasing and then contacting the treated surface with an aqueous bath solution of KF. The concentration of KF in the solution is 2.0-25.0 wt. % and the temperature is 90-212° F. for at least 5 seconds.

Abstract: Anodized aluminum surfaces are advantageously sealed by an energy- and time-saving two step process, in which the first step is contact at not more than 75° C. with a solution containing lithium and fluoride ions and, optionally, surfactant. The second necessary step is treatment with hot water or steam, which may be completed in considerably less time when only hot water or steam is used for sealing. Conventional smut inhibitors and/or neutral buffers as used in hot water for single step sealing may advantageously be included in the second step of this process. 100-1000 ppm concentrations of nickel and/or cobalt ions in the treatment liquid for the second treatment step, if environmentally tolerable, make it possible to complete this step in as little as 10 minutes at a temperature as low as 88° C.

Abstract: A conversion coating solution and process forms a stable and corrosion-resistant layer on metal substrates or layers or, more preferably, on a boehmite layer or other base conversion coating. The conversion coating process involves contacting the substrate, layer or coating with an aqueous alkali metal isomolybdate solution in order to convert the surface of the substrate, layer or coating to a stable conversion coating. The aqueous alkali metal molybdates are selected from sodium molybdate (Na2MoO4), lithium molybdate (Li2MoO4), potassium molybdate (K2MoO4), or combinations thereof, with the most preferred alkali metal molybdate being sodium molybdate. The concentration of alkali metal molybdates in the solution is preferably less than 5% by weight.

Abstract: There is provided a method for treating the surface of metals such as nickel based or high alloy steels, austenitic and ferritic stainless steels, copper and aluminum alloys to increase their corrosion resistance by modification of the metal surfaces to inhibit cathodic corrosion processes. In a single step treatment process the metals are immersed into a heated aqueous composition containing a rare earth salt substantially free of any halide compound. Increased corrosion resistance is obtained using nitrates of yttrium, gadolinium, cerium, europium, terbium, samarium, neodymium, praseodymium, lanthanum, holmium, ytterbium, dysprosium, and erbium nitrates. The rare earth salt is present in the range from about 2% by weight to saturation of the solution. The composition includes a pH-modifying substance such as nitric acid to adjust the pH in the range 0.5 to about 6.5 to attack the surface to remove oxides facilitating deposition of the rare earth.