Abstract: An anodizing electrolyte containing a polyethylene glycol dimethyl ether and an electrochemical process for anodizing valve metals which permits the formulation of an anodic layer having a substantially uniform thickness and reduced flaw density.

Abstract: Copper alloys of aluminum are afforded extended protection against surface corrosion by anodizing the aluminum surface to be protected, treating the surface with a heterocyclic aromatic azole treating agent having up to 16 carbon atoms before, during or after the anodizing step, and coating the treated surface after anodize with a fatty acid of 5 to 24 carbon atoms.

Abstract: A twice-anodized aluminum substrate is anodized sequentially in first and second aqueous electrolytes. In the first, the substrate is conventionally anodized to produce (i) a porous anodic oxide layer having open pores and a passivation layer thereunder. The substrate, now singly-coated, is then anodized in the second electrolyte of an aqueous solution of an organophosphorus compound which generates a residue which is chemisorbed and covalently bonded to the substrate to form (ii) a monomolecular essentially continuous monolayer on the outer surface of (i), and at the same time, the second anodizing step produces (iii) a barrier layer of non-porous aluminum oxide under (i). The thickness of this barrier layer can be increased as a function of the voltage used while maintaining the thickness of (i) substantially constant, and (ii) protects (i) from dissolution.

Abstract: The disclosure relates to insulated metal substrates and to a process for producing these substrates. These substrates have an aluminium base, an insulant constituted by an alumina film obtained by anodizing at least one of the faces of said base and at least one metal film which is to be transformed by chemical etching into a network of conductors. The alumina film is formed by a uniform compact zone adhering to the aluminium and having a thickness in excess of 500 nm and a porous layer with a rough outer surface. The process of making these substrates includes a step during which at least one of the faces of the aluminium base undergoes a treatment in a porous anodization layer forming bath and then in a barrier anodization layer forming bath. The invention is used in the production of substrates for single face, double face, with metallized holes, and multilayer conductive circuits. The substrates produced have a planar or non-planar configuration, and may also have resistive networks.

Abstract: A process for the production of white and black oxide ceramic surface films on silicon-containing light metal cast alloys by plasma-chemical anodic oxidation. An aluminum cast alloy is pickled with nitric acid and hydrofluoric acid and coated by plasma-chemical anodic oxidation in an aqueous electrolyte. Accordingly, a coating variant is provided particularly for construction parts of silicon-containing light metal cast alloys having complicated shapes which enables the production of uniformly thin oxide ceramic surface films in contrast to conventional coating variants.

Abstract: A method is disclosed for producing an anodized film on titanium, its alloys and other metals such that the film deposited will have a specific leak rate of less than one nanoamp per square centimeter at room temperature with an impressed electric field of at least five volts, where the anodization is performed in a solution consisting of liquid ortho-phosphoric acid of reduced water content in an aprotic solvent, and articles of manufacture therefrom.

Abstract: A method and apparatus for retarding the pitting of aluminum by coating the luminum with a film which includes molybdenium oxide.The aluminum material is preexposed to a molybdate solution before anadizing in a sodium tartrate solution.

Abstract: The invention relates to a method of producing aluminum capacitor foil adapted for use in high voltage AC motor start capacitors. Aluminum foil is electrolytically etched in a hot aqueous solution of sodium cloride and then immersed in a hot solution of nitric acid. The foil is immediately thereafter passivated in a dilute aqueous solution of phosphoric acid. The passivated foil is electrolytically treated at a first voltage of at least 150 but not greater than 250 volts in a solution of an ammonium salt of a phosphate, a silicate or a vanadinate to substantially reduce the leakage current, and further electrolytically treated at a second voltage of a magnitude about twice that of the first voltage in a solution of an ammonium salt of an aliphatic dicarboxylic acid of at least 9 carbon atoms and ammonium phosphate until an essentailly amorphous oxide is formed on the foil.

Abstract: Capacitor structure capable of achieving increased energy storage density is disclosed together with a fabrication sequence for the capacitor and its anodic oxide dielectric material. Soft porous aluminum oxide which has been formed in a first anodization step and has been densified or transformed to hard barrier oxide in a second anodization step is preferred for the capacitor dielectric material. The first anodization may be performed in a sulfuric acid electrolyte while the second anodization may be performed in a boric acid electrolyte. The boric acid may be diluted with ethylene glycol. The disclosed capacitor is fabricated on a silicon wafer substrate.

Abstract: There is provided a method of producing an electrode foil for use in aluminum electrolytic capacitors. This method includes the steps of (a) introducing a predetermined length of an aluminum foil into an electrolytic solution without supplying any current; (b) supplying a current to the aluminum foil until voltage becomes constant while keeping the aluminum foil stationary therein; (c) repeating the steps (a) and (b) for another predetermined length of the aluminum foil; and (d) finally holding the aluminum foil thus obtained while applying a constant voltage thereto. According to this method, an excellent electrode foil can be obtained which provides an aluminum electrolytic capacitor with high capacitance and significantly reduced leakage current.

Abstract: A process is disclosed for treating the surface of a valve metal such as aluminum to form a two layer protective coating thereon using an anodizing bath consisting essentially of an aqueous solution having a concentration ranging from about 0.001 molar to a saturated solution of a phosphorus-containing compound selected from the class consisting of a phosphorus acid ester and salts thereof. A non-porous barrier valve metal oxide layer is formed on a surface of the valve metal, and a functionalized layer comprised of a phosphate ester is formed on the oxide layer.