Copper alloy with a golden visual appearance

• US 6,432,556 B1
• Filed: 04/28/2000
• Issued: 08/13/2002
• Est. Priority Date: 05/05/1999
• Status: Expired due to Term

• Current Assignee: Wieland Rolled Products North America, LLC
• Original Assignee: OLIN Corporation
• Inventors: Shapiro, Eugene, Klein, Kip D., Yarwood, John C., Breedis, John F., Brauer, Dennis R.
• Primary Examiner(s): Zimmerman, John J.
• Application Number:
  US09/561,110
• Time in Patent Office: 837 Days
• Field of Search: 428/675, 428/579, 428/686, 428/931, 428/925, 420/481, 420/482, 40/275
• US Class Current: 428/579
• CPC Class Codes: B32B 15/01 all layers being exclusively metallic making layered metal workpieces by pressure cladding B23K20/22; making coatings with a metallic material characterised by its composition C23C30/00
• CPC Class Codes: C22C 9/04 with zinc as the next major constituent
• CPC Class Codes: C22C 9/05 with manganese as the next major constituent
• CPC Class Codes: Y10S 428/931 Components of differing electric conductivity
• CPC Class Codes: Y10T 428/12243 Disk
• CPC Class Codes: Y10T 428/1291 Next to Co-, Cu-, or Ni-base component

Abstract

There is provided a copper-base alloy useful for coinage that has a golden visual appearance. The material has a transverse electrical conductivity substantially similar to that of copper alloy C713 and when clad to a copper alloy C110 core, a transverse electrical conductivity substantially similar to both sides of a Susan B. Anthony United States dollar coin. The copper-base alloy is a copper-manganese-zinc-nickel alloy.

Claims

1. A copper alloy resistant to short range ordering and having a golden visual appearance consisting essentially, by weight, of:

from 5% to 10% of manganese;

from 10% to 14% of zinc;

from 3.5% to 4.5% of nickel;

less than 0.07% aluminum; and

the balance copper and inevitable impurities, said copper alloy having an electrical conductivity in excess of 4% IACS at eddy current gauge exciting frequencies of between 60 kHz and 480 kHz.

2. The copper all alloy of claim 1 having a chromium content of less than 0.3% by weight.

3. The copper alloy of claim 2 wherein said electrical conductivity is between 5% IACS and 7% IACS.

4. The cooper alloy of claim 3 wherein said manganese content is from 6.0% to 7.0% and said zinc content is from 11% to 12%.

5. The copper alloy of claim 3 having attributes of lightness, chroma and hue commensurate with a golden visual appearance.

6. The copper alloy of claim 5 wherein said manganese content is from 6.0% to 7.0% and said zinc content is from 11% to 12%.

7. A planchet formed from the copper alloy of claim 1.

8. An electrical connector formed from the copper alloy of claim 1 having an internal elastic stress and a resistance to stress relaxation.

9. The connector of claim 8 having a less than 27.6 MPa (4 ksi) increase in strength when the alloy is relief annealed from a 50% cold rolled condition.

10. The connector of claim 8 having more than 90% stress remaining following exposure to 125°

C. for 1000 hours.

11. The copper alloy of claim 1 wherein said short range ordering is manifest by an increase in strength in excess of 27.6 MPa following relief annealing of said copper alloy in a 50% cold rolled condition.

12. A clad material, comprising:

a core having a first thickness defined by first and second opposing surfaces, said core formed from a material selected from the group consisting of copper and copper alloys having an electrical conductivity in excess of 90% IACS;

a first cladding layer having a second thickness and bonded to said first opposing surface; and

a second cladding layer having a third thickness and bonded to said second opposing surface, wherein said first cladding layer and said second cladding layer are copper base alloys each consisting essentially, by weight, of from 5% to 10% of manganese, from 10% to 14% of zinc, from 2% to 6% of nickel, with the balance copper and inevitable impurities, said first cladding layer and said second cladding layer each having an electrical conductivity of at least 4% IACS at eddy current gauge exciting frequencies of between 60 kHz and 480 kHz, said first thickness, said second thickness and said third thickness individually selected such that said clad material has a transverse electrical conductivity within about 2% IACS of a Susan B. Anthony United States dollar at eddy current gauge exciting frequencies of between 60 kHz and 480 kHz.

13. The clad material of claim 12 wherein said core has an electrical conductivity in excess of 99% IACS.

14. The clad material of claim 13 wherein said core is copper alloy C110.

15. The clad material of claim 14 wherein said first cladding layer and said second cladding layer each have a chromium content of less than 0.3%, by weight.

16. The clad material of claim 15 wherein said first cladding layer and said second cladding layer each have an electrical coductivity is between 5% IACS and 7% IACS.

17. The clad material of claim 16 wherein said first cladding layer and said second cladding layer each with said manganese content between 6.0% to 7.0% said zinc content between 11% to 12% and said nickel content between 3.5% to 4.5%.

18. The clad material of claim 17 wherein said first cladding layer and said second cladding layer each have an aluminum content of less than 0.07%.

19. The clad material of claim 16 wherein said first cladding layer and said second cladding layer each have attributes of lightness, chroma and hue commensurate with a gold visual appearance.

20. The clad material of claim 19 wherein said first cladding layer and said second cladding layer each said manganese content between 6.0% to 7.0%, said zinc content between 11% to 12% and said nickel content between 3.5% to 4.5%.

21. The clad material of claim 19 wherein said first cladding layer and said second cladding layer each have a thickness of from 20%-30%, by thickness, of the overall thickness and said core has a thickness from about 40% to about 60% by thickness, of said overall thickness.

22. The clad material of claim 21 wherein said first cladding layer and said second cladding layer each have a thickness of about 25%, by thickness, of said overall thickness and said core has a thickness of about 50%, by thickness, of said overall thickness.

23. A planchet formed from the clad material of claim 21.