Multicorrosion protection system for decorative parts with chrome finish
AssigneeMacDermid Enthone Inc.
InventorsAndreas Konigshofen, Ronny Kiefer
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Abstract
The invention relates to a corrosion protection layer system for metal surfaces, said layer system comprising as the two top most layers: a) a discontinuous nickel-phosphorus layer and b) a chromium layer plated from a trivalent chromium electrolyte solution, and method of producing such a corrosion protection layer system. The corrosion protection layer system provides corrosion resistance of the nickel-phosphorus layer against sodium chloride with the protection of the chromium layer produced from a trivalent process again magnesium salts, without the need for any post-treatment.
Claims6
A corrosion protection layer system for metal surfaces, said layer system comprising as the two top most layers:
- a) a discontinuous nickel-phosphorus layer deposited by electroplating and
- b) a chromium layer over the discontinuous nickel-phosphorus, plated from a trivalent chromium electrolyte solution by electroplating,
- wherein said discontinuous nickel-phosphorus layer comprises phosphorus in an amount between 2.0 wt. % and 20 wt. %, where the total weight of the nickel-phosphorus is 100 wt. %, and wherein the discontinuous nickel-phosphorus layer comprises micropores and/or microcracks between 100 and 1,000,000 micropores per cm2 and/or between 10 and 10,000 cracks per cm and wherein said discontinuous nickel-phosphorus layer comprises inorganic solids co-plated from the nickel electrolyte solution.
Dependencies are inferred from the claim text.