Atotech Deutschland Gmbh

Maulik Dhanesh Mehta

Nayan H Joshi

Paul Andrew Butkovsky

The present invention provides a non-cyanide aqueous acidic immersion plating solution having a pH of from about 3.5 to about 6.5 and comprising zinc ions, nickel ions and/or cobalt iron ions, and fluoride ions. In one embodiment the immersion plating solutions of the invention also contain at least one inhibitor containing one or more nitrogen atoms, sulfur atoms, or both nitrogen and sulfur atoms. The present invention also relates to methods for depositing zinc alloy protective coatings on aluminum and aluminum alloy substrates comprising immersing the aluminum or aluminum alloy substrate in the non-cyanide acidic immersion plating solutions of the invention. Optionally, the zinc alloy coated aluminum or aluminum alloy substrate is plated using an electroless or electrolytic metal plating solution.

Aqueous acidic immersion plating solutions and methods for plating on aluminum and aluminum alloys

A process for cleaning (e.g., desmutting) an aluminum surface, using compositions free of nitric acid and chromic acid and comprising, in one embodiment, an oxidant and at least one mineral acid salt. In another embodiment, the process uses a composition free of nitric acid and chromic acid and comprising an oxidant, at least one mineral acid salt, and a complexing agent which is a salt of an organic acid. Due at least in part to the absence of nitric and chromic acids, and in particular, strong mineral acids, the cleaning processes of the present invention remove smut residues from aluminum surfaces without significant etching of the aluminum.

Process for cleaning aluminum and aluminum alloy surfaces with nitric acid and chromic acid-free compositions

The present invention relates to methods for depositing zincate coatings on aluminum and aluminum alloys comprising applying an immersion zincate coating on an aluminum or aluminum alloy substrates, optionally followed by plating the zincate coated aluminum or aluminum alloy substrate using an electroless or electrolytic metal plating solution. The present invention also relates to an improved aqueous alkaline zincate solution comprising hydroxide ions, zinc ions, nickel ions and/or cobalt iron ions, copper ions, and at least one inhibitor containing one or more nitrogen atoms, sulfur atoms, or both nitrogen and sulfur atoms provided said nitrogen atoms are not present in an aliphatic amine or hydroxylamine.

Aqueous alkaline zincate solutions and methods

The present invention provides an improved aqueous alkaline zincate solution comprising hydroxide ions, zinc ions, nickel ions and/or cobalt iron ions, copper ions, and at least one inhibitor containing one or more nitrogen atoms, sulfur atoms, or both nitrogen and sulfur atoms provided said nitrogen atoms are not present in an aliphatic amine or hydroxylamine. The present invention also relates to methods for depositing zincate coatings on aluminum and aluminum alloys comprising applying an immersion zincate coating on an aluminum or aluminum alloy substrates, optionally followed by plating the zincate coated aluminum or aluminum alloy substrate using an electroless or electrolytic metal plating solution.

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Charlotte, NC, United States of America

Maulik Dhanesh Mehta