Claims
- 1. A chromium plating bath comprising:
- ______________________________________(a) chromic acid 100-400 g/l(b) sulfoacetic acid 15-100 g/l(c) dichromate ion 0-100 g/l(d) sulfate ion 0-3 g/l, and(e) fluoride ion 0-8 g/l,______________________________________
- which bath is substantially free of iodide, selenide and bromide ions.
- 2. A process for producing a microporous chromium electrodeposit which comprises electroplating from the chromium plating bath of claim 1.
- 3. A chromium plating bath comprising:
- ______________________________________(a) chromic acid 250-300 g/l(b) sulfoacetic acid 30-60 g/l(c) dichromate ion 40-60 g/l(d) sulfate ion 0.85-1.8 g/l, and(e) fluoride ion 0.2-0.8 g/l,______________________________________
- which bath is substantially free of iodide, selenide, and bromide ions.
- 4. A chromium plating bath according to claim 3 wherein the Cr/SO.sub.4 ratio is about 300:1 to 500:1.
- 5. A process for producing a microporous chromium electrodeposit which comprises electroplating from the chromium plating bath of claim 3.
- 6. A process according to claim 5 wherein the current density is about 0.25-2.5 asi, the temperature is about 50.degree.-160.degree. F., the current efficiency is at least 20% at 1 asi, the porosity is at least the 20,000 micropores per sq. inch of its surface area at a thickness of less than 30.times.10.sup.-6 in.
- 7. A process according to claim 6 in which about 65,000 to 400,000 micropores per sq. inch are present at a thickness of electrodeposit of about 5-20.times.10-6 inches.
CROSS-REFERENCE TO RELATED PATENT APPLICATION
This application is a continuation-in-part of Ser. No. 014,312, filed Feb. 13, 1987 and now abandoned.
US Referenced Citations (6)
Foreign Referenced Citations (1)
Number |
Date |
Country |
2317395 |
Jan 1974 |
DEX |
Continuation in Parts (1)
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Number |
Date |
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Parent |
14312 |
Feb 1987 |
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