Granted Patent B2

US 7,789,978 · App. 10/488,848 · Granted Sep 7, 2010

Abstract

Claims (29)

1. An Al alloy suitable for processing into a lithographic sheet, the alloy having a composition in wt %:

Fe up to 0.4

Si up to 0.25

Ti up to 0.05

Cu up to 0.05

Zr up to 0.005

Cr up to 0.03

Ni up to 0.006

V 0.005 to 0.03

Zn 0.008 to 0.15

Mg up to 0.30

Mn up to 1.5

Unavoidable impurities up to 0.05 wt % each, 0.15 wt % total Al balance,

and wherein the Zn/V ratio is at least about 0.6.

2. An alloy according to claim 1 , wherein Zn is present in an amount of 0.01 to 0.15 wt %.

3. An alloy according to claim 1 , wherein Zn is present in an amount of 0.013 to 0.05 wt %.

4. An alloy according to claim 1 , wherein V is present in an amount of 0.013 to 0.03 wt %.

5. An alloy according to claim 1 , wherein the Zn/V ratio is at least about 1.

6. An alloy according to claim 1 , wherein the Zn/V ratio is at least about 2.

7. An alloy according to claim 1 , wherein Fe is present in an amount of 0.25-0.4 wt %.

8. An alloy according to claim 1 , wherein Si is present in an amount of 0.07-0.20 wt %.

9. An alloy according to claim 1 , wherein Cu is present in an amount up to 0.01 wt %, preferably 0.004 wt %.

10. An alloy according to claim 1 , wherein Cr is present in an amount up to 0.004 wt %.

11. An alloy according to claim 1 , wherein Ti is present in an amount of up to 0.03 wt %.

12. An alloy according to claim 1 , wherein Mg is present in an amount of 0.05 to 0.30 wt %.

13. An alloy according to claim 1 , wherein Mn is present in an amount of up to 0.25 wt %.

14. An alloy according to claim 1 , wherein Mn is present in an amount of 0.05 to 0.25 wt %.

15. A lithographic sheet formed from the alloy of claim 1 .

16. The method of using an alloy of claim 1 comprising forming a lithographic sheet from said alloy.

Assignments (24)