Anodized-quality aluminum alloys and related products and methods

Patent metadata

Field	Value
Publication number	US-10538833-B2
Application number	US-201715634199-A
Country	US
Kind code	B2
Filing date	Jun 27, 2017
Priority date	Jun 28, 2016
Publication date	Jan 21, 2020
Grant date	Jan 21, 2020

Abstract

Disclosed are alloys for anodized-quality aluminum sheets with improved surface quality, and methods for making these sheets. The alloys are designed to minimize the formation of cathodic intermetallic particles that result in surface streaks of anodized sheet products formed from the alloys. Further, the alloys allow the incorporation of recycled scrap aluminum in anodized-quality sheets.

First claim

What is claimed is:

1. An aluminum alloy, comprising 0.10-0.30 wt. % Fe, 0.10-0.30 wt. % Si, 0-0.25 wt. % Cr, 2.0-3.0 wt. % Mg, 0.05-0.10 wt. % Mn, 0.02-0.06 wt. % Cu, unavoidable impurities up to 0.05 wt. % for each impurity, up to 0.15 wt. % for total impurities, and the balance aluminum, wherein the aluminum alloy comprises Si and Fe in a Si:Fe ratio of from 0.67:1 to 2.5:1.

2. The aluminum alloy of claim 1 , comprising 0.15-0.24 wt. % Fe and 0-0.20 wt. % Cr.

3. The aluminum alloy of claim 1 , comprising 0.15 wt. % Fe, 0.30 wt. % Si, 2.4 wt. % Mg, 0.07 wt. % Mn, and 0.04 wt. % Cu.

4. The aluminum alloy of claim 1 , wherein the ratio of Si:Fe ratio is from 0.67:1 to 2.0:1.

5. The aluminum alloy of claim 1 , comprising from about 1% to about 90% recycled content.

6. A sheet comprising the aluminum alloy of claim 1 .

7. The sheet of claim 6 , wherein the sheet has a cathodic particle density of no more than 2000 particles per square millimeter.

8. The sheet of claim 7 , wherein the sheet has a cathodic particle density of no more than 120 particles per square millimeter.

9. The sheet of claim 6 , wherein the sheet is an anodized sheet.

10. The sheet of claim 9 , wherein the anodized sheet has a density of etch pits of less than 2000 pits per square millimeter.

11. The sheet of claim 9 , wherein the anodized sheet is free of etch pits having a measurement in any dimension of greater than or equal to 5 μm.

12. An article comprising the aluminum alloy of claim 1 , wherein the article is a consumer electronic product part, an automobile body part, an architectural part, or a lithographic part.

13. A method of preparing an aluminum sheet, comprising:
casting an aluminum alloy to form an ingot;
homogenizing the ingot;
hot rolling the ingot to produce a hot rolled intermediate product;
cold rolling the hot rolled intermediate product to produce a cold rolled intermediate product;
interannealing the cold rolled intermediate product to produce an interannealed product;
cold rolling the interannealed product to produce a cold rolled sheet; and
annealing the cold rolled sheet to form an annealed sheet, wherein the aluminum alloy comprises 0.10-0.30 wt. % Fe, 0.10-0.30 wt. % Si, 0-0.25 wt. % Cr, 2.0-3.0 wt. % Mg, 0.05-0.10 wt. % Mn, 0.02-0.06 wt. % Cu, unavoidable impurities up to 0.05 wt. % for each impurity, up to 0.15 wt. % for total impurities, and the balance aluminum, and wherein the aluminum alloy comprises Si and Fe in a ratio of Si:Fe from 0.2:1 to 2.5:1.

Assignees

• Novelis Inc

Inventors

• Kang Daehoon
• Wen Wei
• Mathur Devesh

Classifications

• C22F1/047 Primary

  of alloys with magnesium as the next major constituent · CPC title

• C25D11/04

  of aluminium or alloys based thereon · CPC title

• B21B2003/001

  Aluminium or its alloys · CPC title

• C22C21/08

  with silicon · CPC title

• B22D7/005

  from non-ferrous metals · CPC title