High strength aluminum alloy sheet for anodic oxide coated material and method of producing same and high strength anodic oxide aluminum alloy sheet

Patent metadata

Field	Value
Publication number	US-10131971-B2
Application number	US-201314912342-A
Country	US
Kind code	B2
Filing date	Aug 13, 2013
Priority date	Aug 13, 2013
Publication date	Nov 20, 2018
Grant date	Nov 20, 2018

Abstract

An aluminum alloy sheet which is high in strength and excellent in heat conductivity, and which can be given an anodic oxide coating with a white color and a suitable yellowishness is provided. An aluminum alloy ingot containing Mg: 0.80 to 1.8 mass %, Fe: 0.05 to 0.30 mass %, Si: 0.20 mass % or less, Cu: 0.03 to 0.15 mass %, Mn: 0.05 to 0.20 mass %, and Cr: 0.05 to 0.15 mass %, restricts Zn to less than 0.15 mass %, and balance of Al and unavoidable impurities is treated by holding it at 560 to 620° C. for 1 to 5 hours, then hot rolled and, either through or not through process annealing, and cold rolled by a final cold rolling reduction of 15 to 95% to obtain an aluminum alloy sheet which has a 0.2% yield strength of 180 MPa or more and a conductivity of 40 (IACS %) or more.

First claim

The invention claimed is:

1. A high strength anodic oxide coated aluminum alloy sheet characterized by having an anodic oxide coating with a color range of
an L* value of from 85 to 90, an a* value of from −1.0 to −0.3 and a b* value of from 0.5 to 1.0 provided by subjecting a high strength aluminum alloy sheet for anodic oxide coating treatment to pretreatment by alkaline etching, and further to sulfuric anodic oxide coating treatment,
wherein said sheet contains:
Mg: 0.80-1.8 mass %, Fe: 0.05-0.30 mass %, Si: 0.20 mass % or less, Cu: 0.03-0.15 mass %, Mn: 0.05-0.20 mass %, and Cr: 0.05-0.15 mass %, with Zn controlled to less than 0.15 mass %, the balance consisting of Al and unavoidable impurities, and having a 0.2% proof strength of 180 MPa or more and an electric conductivity of 40 (IACS %) or more.

2. The high strength anodic oxide coated aluminum alloy sheet according to claim 1 , wherein said sheet is characterized by having an integrated diffraction intensity ratio (Iα-Al(Fe—Mn)Si/IA 3 Fe) of 0.1-0.8.

3. The high strength anodic oxide coated aluminum alloy sheet according to claim 1 for use as a housing of electronic equipment in combination with an anodic oxide coated JIS A5052 alloy sheet.

4. The high strength anodic oxide coated aluminum alloy sheet according to claim 1 , wherein said sheet contains: 0.85 to 1.7 mass % of Mg, 0.07 to 0.28 mass % of Fe, 0.18 mass % or less of Si, 0.03 to 0.12 mass % of Cu, 0.05 to 0.18 mass % of Mn, and 0.05 to 0.12 mass % of Cr, with Zn controlled to less than 0.12 mass %.

5. The high strength anodic oxide coated aluminum alloy sheet according to claim 1 , wherein said sheet contains: 0.90 to 1.6 mass % of Mg, 0.10 to 0.25 mass % of Fe, 0.15 mass % or less of Si, 0.03 to 0.10 mass % of Cu, 0.05 to 0.15 mass % of Mn, and 0.03 to 0.10 mass % of Cr, with Zn controlled to less than 0.10 mass %.

6. The high strength anodic oxide coated aluminum alloy sheet according to claim 1 , wherein said sheet contains: 0.85 to 1.7 mass % of Mg.

7. The high strength anodic oxide coated aluminum alloy sheet according to claim 1 , wherein said sheet contains: 0.90 to 1.6 mass % of Mg.

8. The high strength anodic oxide coated aluminum alloy sheet according to claim 1 , wherein said sheet contains: 0.05 to 0.21 mass % of Fe.

9. The high strength anodic oxide coated aluminum alloy sheet according to claim 1 , wherein said sheet contains: 0.05 to 0.15 mass % of Cu.

10. The high strength anodic oxide coated aluminum alloy sheet according to claim 1 , wherein said sheet contains: 0.07 to 0.20 mass % of Mn.

11. The high strength anodic oxide coated aluminum alloy sheet according to claim 1 , wherein said sheet contains: 0.07 to 0.15 mass % of Cr.

12. A process of producing a high strength anodic oxide coated aluminum alloy sheet according to claim 1 , said process comprising: providing an aluminum alloy ingot having a chemical composition as set forth in claim 1 , homogenizing said ingot by holding at a temperature of 560-620° C. for 1-5 hours, then hot rolling, and cold rolling at a final cold rolling reduction of 15-95% with or without process annealing, and subjecting a resulting aluminum allow sheet to pretreatment by alkaline etching, and further to sulfuric anodic oxide coating treatment.

13. The process according to claim 12 , further comprising final annealing after said cold rolling.

Assignees

• Nippon Light Metal Co

Inventors

• Oota Atsushi
• Otake Fumio
• Handa Takeshi

Classifications

• Y10T428/1259

  Oxide · CPC title

• Y10T428/12764

  Next to Al-base component · CPC title

• Y10T428/12667

  Oxide of transition metal or Al · CPC title

• Y10T428/12597

  Noncrystalline silica or noncrystalline plural-oxide component [e.g., glass, etc.] · CPC title

• C22F1/04

  of aluminium or alloys based thereon · CPC title