Methods and electrolyte compositions for electrodepositing chromium coatings
AssigneeThe United States of America as represented by the Secretary of Commerce
InventorsChristian E. Johnson, David Lashmore, Elaine Soltani
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Abstract
Methods for electrodepositing a chromium coating on a substrate comprising mmersing the substrate in an aqueous electrolyte, and passing a sufficient current through the electrolyte to effect deposition of a chromium coating on the substrate. The aqueous electrolytes comprise from about 0.2 to about 0.6 mol/l of trivalent chromium ions, greater than about 1.4 mol/l of an amidosulfonic acid or a salt thereof, ammonium ions, formic acid or a salt thereof, and water.
Claims24
A method for electrodepositing a chromium coating on a substrate, comprising immersing the substrate in an aqueous electrolyte, and passing a sufficient current through the electrolyte to effect deposition of a chromium coating on the substrate, the aqueous electrolyte comprising from about 0.2 to about 0.6 mol/l of trivalent chromium ions, greater than about 1.4 mol/l of an amidosulfonic acid or a salt thereof, ammonium ions, formic acid or a salt thereof, and water.
An aqueous solution for electrodepositing a chromium coating, comprising from about 0.2 to about 0.6 mol/l trivalent chromium ions, greater than about 1.4 mol/l of an amidosulfonic acid or a salt thereof, ammonium ions, formic acid or a salt thereof, and water.
Dependencies are inferred from the claim text.