Black chromium-containing conversion coatings on zinc-nickel and

Details Black chromium-containing conversion coatings on zinc-nickel and Black chromium-containing conversion coatings on zinc-nickel and

1993-09-02

1995-05-16

Silverberg, Sam

Metal treatment

Process of modifying or maintaining internal physical...

Processes of coating utilizing a reactive composition which...

148267, C23C 2208

Patent

active

054157021

ABSTRACT:
A method is described for preparing a black chromium-containing conversion coating on a zinc-nickel alloy surface containing at least about 8% nickel in the alloy or on a zinc-iron alloy surface. The method of the invention comprises contacting said surfaces with an aqueous acidic solution comprising trivalent chromium and an amount of a phosphorus acid selected from phosphoric acid, phosphorous acid, hypophosphorous acid, and mixtures thereof effective to provide a solution having a pH of from about 1.0 to about 2.5. Metal articles having zinc-nickel alloy surfaces containing at least about 8 % nickel in the alloy or having zinc-iron alloy surfaces which have been treated in accordance with the method of the invention exhibit the desired blackened surfaces and are characterized by improved corrosion resistance.

REFERENCES:
patent: 2559878 (1951-07-01), Johnson
patent: 2768104 (1956-10-01), Schuster
patent: 3501352 (1970-03-01), Shah
patent: 3535168 (1970-10-01), Thompson
patent: 3647569 (1972-03-01), Schneider
patent: 3932198 (1976-01-01), Schneider
patent: 4141758 (1979-02-01), Glassman et al.
patent: 4171231 (1979-10-01), Bishop et al.
patent: 4263059 (1981-04-01), Gudde et al.
patent: 4578122 (1986-03-01), Crotty
patent: 4657599 (1987-04-01), Sutherland

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