Coinage cladding alloy and processing for making coinage cladding alloy

Patent metadata

Field	Value
Publication number	US-10513768-B2
Application number	US-201615297393-A
Country	US
Kind code	B2
Filing date	Oct 19, 2016
Priority date	Oct 19, 2016
Publication date	Dec 24, 2019
Grant date	Dec 24, 2019

Abstract

A coinage cladding alloy for coinage includes nickel present in an amount from 5 wt. % to 7 wt. %, based on a total weight of the coinage cladding alloy; zinc present in an amount from 21 wt. % to 29 wt. %, based on the total weight of the coinage cladding alloy; manganese present in an amount from 12 wt. % to 16 wt. %, based on a total weight of the coinage cladding alloy; copper; an electrical conductivity from 2% International Annealed Copper Standard (IACS) to 3% IACS; and a color comprising a yellowness vector b* that is from 2 to 10, based on a CIE L*a*b* color space and determined in accordance with ASTM Standard E308-15 (2015).

First claim

What is claimed is:

1. A post-annealed coinage cladding copper alloy for coinage comprising:
nickel present in an amount from 5 wt. % to 7 wt. %, based on a total weight of the coinage cladding alloy;
zinc present in an amount from 21 wt. % to 29 wt. %, based on the total weight of the coinage cladding alloy;
manganese present in an amount from 12 wt. % to 16 wt. %, based on a total weight of the coinage cladding alloy;
copper;
an electrical conductivity from 2% International Annealed Copper Standard (IACS) to 3% IACS measured in accordance with ASTM E1004-09 (2009);
a disordered crystalline phase, wherein atoms of the nickel, copper, zinc, and manganese are randomly arranged in the disordered crystalline phase at room temperature in a post-annealed state;
a hardness of the coinage cladding alloy from 80 VHN to 120 VHN; and
a color comprising a yellowness vector b* that is from 2 to 10, based on a CIE L*a*b* color space and determined in accordance with ASTM Standard E308-15 (2015).

2. The coinage cladding alloy of claim 1 , wherein the copper is present in an amount from 50 wt. % to 60 wt. %, based on the total weight of the coinage cladding alloy.

3. The coinage cladding alloy of claim 1 , wherein the disordered crystalline phase comprises a single phase.

4. The coinage cladding alloy of claim 3 , wherein the single phase is a face-centered cubic phase.

5. The coinage cladding alloy of claim 3 , wherein the electrical conductivity is produced from quenching an annealing alloy from an annealing temperature at a cooling rate effective to produce the coinage cladding alloy in the disordered crystalline phase.

6. The coinage cladding alloy of claim 5 , wherein the cooling rate is greater than or equal to air cooling from the annealing temperature to room temperature.

7. The coinage cladding alloy of claim 1 , wherein a yield strength of the coinage cladding alloy is from 100 MPa to 180 MPa.

8. The coinage cladding alloy of claim 1 , wherein the electrical conductivity is selected such that a coin comprising the coinage cladding alloy is acceptable as currency in a vending machine that accepts the coin.

9. A process for making the post-annealed coinage cladding copper alloy for coinage of claim 1 , the process comprising:
heating an alloying composition to a first temperature that is greater than or equal to an annealing temperature to form an annealing alloy, the alloying composition comprising:
nickel present in an amount from 5 wt. % to 7 wt. %, based on a total weight of the alloying composition;
zinc present in an amount from 21 wt. % to 29 wt. %, based on the total weight of the alloying composition;
manganese present in an amount from 12 wt. % to 16 wt. %, based on a total weight of the alloying composition; and
copper; and
quenching, by cooling the annealing alloy from the first temperature to a second temperature that is less than the annealing temperature.

Assignees

• Government Of The Unites States Of America As Represented By The Secretary Of Commerce
• Government Of The Us Secretary Of Commerce

Inventors

• Lass Eric A
• Stoudt Mark R
• Campbell Carelyn
• Ying Tsineng Tony

Classifications

• C22C9/04

  with zinc as the next major constituent · CPC title

• C22C1/02

  by melting {(C22C1/1036 takes precedence)} · CPC title

• B32B15/01

  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 title

• A44C21/00

  Coins (coins specially adapted to operate coin-freed mechanisms G07F1/06); Emergency money; Beer or gambling coins or tokens, or the like · CPC title

• C22F1/08 Primary

  of copper or alloys based thereon · CPC title