This invention covers the use of a selected group of sulfo-organic compounds as addition agents and particularly as microcracking agents in the electrodeposition of chromium from a conventional chromium plating bath. A particularly effective compound is thio diethanol, which when added to a fluosilicate bath gives a fine microcracked deposit in 21/2 and 6 minutes. At shorter plating times, this compound improves the covering power of the bath.

Microcracked chromium from a bath using an organic sulfur compound

A chromium plating bath which consists essentially of chromic acid and 40-100 g/l of sulfoacetic acid, and which is substantially free of carboxylic acid, fluoride, iodide, bromide and selenium ions, is described herein.

High performance electrodeposited chromium layers

A functional chromium electroplating bath and process is disclosed. The bath comprises chromic acid, sulfoacetic acid, iodate and a nitrogen organic compound. Such a bath gives chromium deposits which are both bright and adherent.

Electroplating bath and process for depositing functional, at high efficiencies, chromium which is bright and smooth

Novel chromium plating baths suitable for electrodepositing chromium layers which are bright, adherent, smooth and hard, and are capable of being formed at both high and low current densities, and at high cathodic current efficiencies, consist essentially of chromic acid and sulfoacetic acid in a concentration range of about 40 to 150 g/l., and selenate or tellurate ion. Sulfate ion, if present, is included in low concentrations such that the Cr/SO 4 ratio is high, preferably 300:1 or more.

High-performance electrodeposited chromium layers formed at high current efficiencies

Electroplating process for depositing bright and smooth functional chromium at high efficiences

THIS INVENTION RELATES TO NOVEL COMPOSITIONS AND TO A PROCESS FOR ELECTROPLATING CHROMIUM PLATE ONTO A BASIS METAL WHICH COMPRISES PASSING CURRENT FROM AN ANODE TO A CATHODE AT LEAST A PORTION OF WHICH CONTAINS A CONDUCTIVE METAL LAYER THROUGH AN AQUEOUS ACIDIC CHROMIUM PLATING SOLUTION CONTAINING: (1) AT LEAST ONE CHROMIUM COMPOUND PROVIDING HEXAVALENT CHROMIUM IONS FOR ELECTROPLATING CHROMIUM; AT LEAST ONE CATALYST SELECTED FROM THE GROUP COMPRISING SULFATE IONS AND FLUORIDE IONS, AND (2) AT LEAST ONE MEMBER OF THE GROUP CONSISTING OF SULFOACETIC ACID, ISETHIONATE AND ISETHIONIC ACID; FOR A TIME SUFFICIENT TO DEPOSIT A CHROMIUM ELECTROPLATE HAVING A THICKNESS OF AT LEAST 1X10**-4 MILLIMETER.

M Best

Papers

Novel cromium plating compositions