Omi International Corporation

Oxy Metal Industries Corporation

Occidental Chemical Corporation

Thaddeus W Tomaszewski

Robert A Tremmel

Lillie C Tomaszewski

Richard John Clauss

Hans-Gerhard Creutz, Deceased

Larry T Rudolph

An improved process and aqueous electrolyte for imparting improved corrosion resistance to chromium substrates, and particularly nickel-plated substrates having a chromium plating thereover deposited from a trivalent chromium electrolyte. The post-treating solution contains solution soluble and compatible hexavalent chromium compounds including chromates and dichromates present in an amount sufficient to deposit a protective film on the chromium substrate and phosphate ions present in an amount of about 2.5 g/l up to the limit of solubility in the electrolyte. The electrolyte optionally, but preferably, further contains a buffering agent present in an amount to stabilize the pH of the solution within a range from about 2.5 up to about 10. Optionally, the electrolyte further contains at least one metal ion selected from the group consisting of nickel, cobalt and mixtures thereof in an amount up to about 2 g/l, conductivity salts to enhance the electrical conductivity of the solution and a compatible wetting agent. In accordance with the process aspects of the invention, the chromium plated substrate is immersed in the electrolyte and is cathodically electrified to effect the passage of current through the solution between an anode and the substrate at an average cathode current density below that at which metallic chromium is deposited on the substrate for a period of time sufficient to deposit a protective film of the desired thickness thereon.

Electrolytic post treatment of chromium substrates

An aqueous acidic trivalent chromium electrolyte and process for electrodepositing chromium platings comprising an electrolyte containing trivalent chromium ions, a complexing agent, halide ions, ammonium ions and a reducing agent comprising a metal ion selected from the group consisting of Gold, Silver, Platinum, Palladium, Rhodium, Iridium, Osmium, Ruthenium, Rhenium, Gallium, Germanium, Indium, Samarium, Europium, Gadolinium, Terbium, Dysprosium, Holmium, Erbium, Thulium, Ytterbium, Lutetium, and Praseodymium present in an amount effective to maintain the concentration of hexavalent chromium ions formed in the bath at a level at which satisfactory chromium electrodeposits are obtained.

Trivalent chromium electrolyte and process employing metal ion reducing

An aqueous acidic trivalent chromium electrolyte and process for electrodepositing chromium platings comprising an electrolyte containing trivalent chromium ions, a complexing agent, halide ions, ammonium ions and a reducing agent comprising an ion selected from the group consisting of scandium, yttrium, lanthanum, titanium, zirconium, hafnium, molybdenum, arsenic, selenium, tellurium, cerium, uranium, and tin present in an amount effective to maintain the concentration of hexavalent chromium ions formed in the bath at a level at which satisfactory chromium electrodeposits are obtained.

Trivalent chromium electrolyte and process employing reducing agents

A cyanide-free electrolyte and process for depositing a ductile, fine-grained, adherent copper plate usually of a thickness of about 0.015 to about 5 mils on ferrous-base, copper-base, zinc-base and the like conductive substrates. The electrolyte contains controlled effective amounts of cupric ions complexed with an organo-phosphonate chelating agent, an alkali carbonate as a bath stabilizing and buffering agent, hydroxyl ions to provide a pH on the alkaline side and preferably, a wetting agent. The copper plate is applied by electrolyzing the aforementioned electrolyte employing a combination of a bath soluble copper anode and an insoluble ferrite anode to provide a copper to ferrite anode surface area ratio within a range of about 1:2 to about 1:6.

Cyanide-free copper plating process

A process for electrodepositing chromium on a conductive substrate employing an electrolyte containing trivalent chromium ions, a complexing agent, and hydrogen ions to provide an acidic pH in which a conductive substrate to be electroplated is immersed in the electrolyte and is cathodically charged and current is passed between the substrate and an anode at least a portion of the surfaces of which is comprised of ferrite whereby the formation of detrimental hexavalent chromium ions in the electrolyte is inhibited and the stability of the pH of the electrolyte is improved.

Trivalent chromium electroplating process

An aqueous acidic trivalent chromium electrolyte and process for electrodepositing chromium platings comprising an electrolyte containing trivalent chromium ions, a complexing agent, halide ions, ammonium ions and a reducing agent comprising neodymium ions present in an amount effective to maintain the concentration of hexavalent chromium ions formed in the bath at a level at which satisfactory chromium electrodeposits are obtained.

Trivalent chromium electrolyte and process employing neodymium reducing

An aqueous acidic trivalent chromium electrolyte and process for electrodepositing chromium platings comprising an electrolyte containing trivalent chromium ions, a complexing agent, halide ions, ammonium ions and a reducing agent comprising vanadium ions present in an amount effective to maintain the concentration of hexavalent chromium ions formed in the bath at a level at which satisfactory chromium electrodeposits are obtained.

Trivalent chromium electrolyte and process employing vanadium reducing

An aqueous acid trivalent chromium electroplating solution and process for forming chromium platings employing a bath containing trivalent chromium, formate ions as a complexing agent, and a bath soluble reducing agent selected from the group consisting of formaldehyde, glyoxal, formaldehye bisulfite, glyoxal di-bisulfite, sodium formaldehyde sulfoxylate, and mixtures thereof. The bath may additionally and preferably contain controlled amounts of conductivity salts, ammonium cations and a buffering agent to maintain the pH within the desired range.

Trivalent chromium plating bath composition and process

An aqueous acidic trivalent chromium electroplating solution and process for depositing chromium platings employing a bath containing trivalent chromium, a complexing agent, a reducing agent and a controlled effective amount of an anionic or nonionic surface active agent selected from the class of organic mono- or di- or tri-ester phosphates which contributes to improve operating characteristics and efficiency of the electroplating bath and enhances the uniformity of the chromium deposit.

Growing community of inventors

Dearborn, MI, United States of America

Thaddeus W Tomaszewski