Method for desmutting aluminum alloys having a highly-reflective surface
AssigneeAluminum Company of America
InventorsPaul B. Schultz, Albert L. Askin
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Abstract
A method of forming a highly-deflective surface on aluminum alloys. The, the composition comprising: cleaning a body formed from an aluminum alloy; electrobrightening the body; and desmutting the surface of the freshly-brightened body without etching. The bath comprises: 15-95 vol. % nitric acid and 1-85 vol. % acetic acid; 1-40 vol. % total water; and a source of fluoride ion supplying at least 35 grams per liter of fluoride. Ammonium bifluoride is the preferred source of fluoride.
Claims20
A method of forming a highly-reflective surface on aluminum alloys, said method comprising:
- cleaning a body formed from an aluminum alloy;
- electrobrightening said body;
- and promptly thereafter
- desmutting the surface of the freshly-brightened body in a bath, said bath comprising:
- 15-95 vol. % nitric acid;
- 1-85 vol. % acetic acid;
- 1-40 vol. % total water;
- and
- a source of fluoride ions supplying at least 35 grams per liter of fluoride.
Electrobrightened sheet product having a highly-reflective surface, said sheet product formed by a method comprising:
- cleaning a body formed from an aluminum alloy;
- electrobrightening said body;
- and
- desmutting the freshly-brightened body in a bath, said bath comprising:
- 15-95 vol. % nitric acid;
- 1-85 vol. % acetic acid;
- 1-40 vol. % total water;
- and
- a source of fluoride ion supplying at least 35 grams per liter of fluoride.
Electrobrightened lighting sheet having a highly-reflective surface, said lighting sheet formed by a method comprising:
- cleaning a body formed from an aluminum alloy;
- electrobrightening said body;
- and
- desmutting the freshly-brightened body in a bath, said bath comprising:
- 15-95 vol. % nitric acid;
- 1-85 vol. % acetic acid;
- 1-40 vol. % total water;
- and
- a source of fluoride ion supplying at least 35 grams per liter of fluoride.
A continuous method of forming a highly reflective surface on aluminum alloys, said method comprising:
- cleaning a body formed from an aluminum alloy containing at least 95 wt. % aluminum;
- electrobrightening said body;
- and promptly thereafter immersing the freshly-brightened body in a bath comprising:
- 15-95 vol. % nitric acid;
- 1-85 vol. % acetic acid;
- 1-40 vol. % total water;
- and
- at least 35 grams per liter of fluoride from ammonium bifluoride;
- said bath being maintained at a temperature in the range of about 60.degree. to 120.degree. F. for less than about 3 minutes to desmut the surface of the freshly-brightened body.
Dependencies are inferred from the claim text.