Method for desmutting aluminum alloys having a highly reflective surface
AssigneeAluminum Company of America
InventorsAlbert L. Askin, Paul B. Schultz
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Abstract
A method of forming a highly reflective surface on aluminum alloys, the composition comprising (a) brightening the surface of a body formed from an aluminum alloy; and (b) desmutting the freshly brightened body in a bath. The desmutting bath comprises 10-100 volume percent nitric acid; 0-60 volume percent sulfuric acid; 0-50 volume percent water; and at least 15 grams per liter of a source of bifluoride. Ammonium fluoride is the preferred source of fluoride.
Claims24
A method of forming a highly reflective surface on aluminum alloys, said composition comprising:
- (a) cleaning a body formed from an aluminum alloy;
- (b) electrobrightening said body;
- and
- (c) desmutting the surface of the freshly brightened body without etching, the desmutting in a bath to remove smut formed on the surface of the body during electrobrightening, said bath comprising:
- 10-100 volume percent nitric acid;
- 0-60 volume percent sulfuric acid;
- 0-50 volume percent water;
- and
- at least 15 grams per liter of a source of fluoride.
A chrome-free bath for desmutting the surface of electropolished aluminum alloys without etching the surface, said bath comprising:
- (a) a solution comprising:
- 10-100 volume percent nitric acid;
- 0-60 volume percent sulfuric acid;
- and
- 0-50 volume percent water;
- and
- (b) at least 15 grams per liter of a source of fluoride.
A chrome-free bath for desmutting the surface of electropolished aluminum alloys without etching the surface, said bath comprising:
- (a) a solution comprising:
- 10-80 volume percent nitric acid;
- 10-60 volume percent sulfuric acid;
- and
- 10-50 volume percent water;
- and
- 5-20 volume percent phosphoric acid;
- and
- (b) at least 15 grams per liter of a source of fluoride.
A chrome-free bath for desmutting the surface of electropolished aluminum alloys without etching the surface, said bath comprising:
- (a) a solution comprising:
- 10-50 volume percent nitric acid;
- 20-60 volume percent sulfuric acid;
- and
- 20-30 volume percent water;
- and
- 5-20 volume percent phosphoric acid;
- and
- (b) at least 15 grams per liter of a source of fluoride.
Electrobrightened sheet product having a highly reflective surface, said sheet product formed by a method comprising:
- (a) cleaning a body formed from an aluminum alloy;
- (b) electrobrightening said body;
- and
- (c) desmutting the freshly brightened body in a bath, said bath comprising:
- 10-100 volume percent nitric acid;
- 0-60 volume percent sulfuric acid;
- 0-50 volume percent water;
- and
- at least 15 grams per liter of a source of fluoride.
Electrobrightened lighting sheet having a highly reflective surface, said lighting sheet formed by a method comprising:
- (a) cleaning a body formed from an aluminum alloy;
- (b) electrobrightening said body;
- and
- (c) desmutting the freshly brightened body in a bath, said bath comprising:
- 10-100 volume percent nitric acid;
- 0-60 volume percent sulfuric acid;
- 0-50 volume percent water;
- and
- at least 15 grams per liter of a source of fluoride.
Dependencies are inferred from the claim text.