Patent ID: 7699970

Claim:
A method of producing a structured hard chrome layer, the method comprising: providing an electrolyte, said electrolyte comprising (a) a Cr (VI) compound in an amount corresponding to 50 g/l to 600 g/l of chromic acid anhydride, (b) 0.5 g/l to 10 g/l of sulphuric acid, (c) 1 g/l to 20 g/l of aliphatic sulphonic acid, that comprises 1 to 6 carbon atoms, and (d) 10 g/l to 200 g/l of at least one compound forming a dense cathode film, said compound being selected from among ammonium molybdate, alkali molybdate, alkaline earth molybdate, ammonium vanadate, alkali vanadate, alkaline earth vanadate, ammonium zirconate, alkali zirconate, and alkaline earth zirconate, wherein the electrolyte comprises substantially no fluorides; electrodepositing chromium from the electrolyte onto a workpiece forming a structured hard chrome layer, wherein a cathodic current yield in the production of the structured hard chrome layer is 12% or less, such that said hard chrome layer comprises at least one of a cup-shaped structure, a labyrinth structure, or a column-shaped structure.