Functional plating from solutions containing trivalent chromium ion
AssigneeElf Atochem North America, Inc.
InventorGeorge E. Shahin
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Abstract
Functional chromium and chromium-alloy deposits are obtained from an electroplating solution having substantially the composition: 22 g/l Cr.sup.+3 ; 250 g/l KCl; 63 g/l H.sub.3 BO.sub.3 ; 30 g/l HCO.sub.2.sup.= ; 15 g/lKBr; and 120 ppm of a wetting agent. The plating solution provides improved efficiency, stress values and appearance over the prior art, and is tolerant of metallic iron and ionic iron and ammonium.
Claims13
An improved solution for electroplating chromium and chromium alloy having trivalent chromium ion, formate and bromide ion, boric acid and a wetting agent, the improvement comprising the electroplating solution having from about 5 to about 60 g/l of trivalent chromium ion, from about 200 to about 300 g/l of potassium ion, from about 50 g/l saturation of boric acid, from about 30 to about 45 g/l of formate ion, from about 5 to about 30 g/l of bromide ion, and from about 75 to about 250 ppm of a wetting agent said solution being substantially free of ammonium ion.
An electroplating solution for plating functional chromium containing trivalent chromium ion consisting essentially of about 22 g/l of trivalent chromium ion, about 250 g/l of potassium ion, about 63 g/l of boric acid, about 30 g/l of formate ion, about 15 g/l of bromide ion, and about 120 ppm of a wetting agent said solution being substantially free of ammonium ion.
In an electroplating solution containing trivalent chromium ion and capable of providing a functional chromium plate in the presence of contaminating ammonium or iron moieties, or both, the improvement which comprises the electroplating solution having about 5 to about 60 g/l of trivalent chromium ion, about 200 to about 300 g/l of potassium ion, about 50 g/l to saturation of boric acid, about 30 to about 45 g/l of formate ion, about 5 to about 30 g/l of potassium ion, and about 75 to about 250 ppm of a wetting agent said solution being substantially free of ammonium ion.
Dependencies are inferred from the claim text.