White-colored copper alloy with reduced nickel content

Abstract

Disclosed is a white-colored copper alloy comprising by weight up to 30% zinc, up to 20% manganese, up to 5% nickel with the balance copper. This alloy may have from 6% to 25% zinc, from 4% to 17% manganese, from 0.1% to 3.5% nickel and the balance copper. The balance copper in the alloy may further contain at least one of: up to 0.5% of at least one of the group which consists of Sn, Si, Co, Ti, Cr, Fe, Mg, Zr, and Ag; and up to 0.1% of at least one of the group which consists of P, B, Ca, Ge, Se, Te. It may also contain up to 0.3% Zr by weight. The alloy may have an electrical conductivity greater than 2.5% IACS at eddy current gauge exciting frequencies between 60 kHz and 480 kHz.

1 ) An effectively antimicrobial copper alloy with a visual appearance similar to one of stainless steel and “nickel silver”, the copper alloy comprising:
 a) 6-25% zinc (Zn)   b) 4-17% manganese (Mn),   c) 0.1-3.5% nickel (Ni),   d) a balance of substantially Cu; and   e) the combination of a-d exhibiting a white visual appearance and is effectively antimicrobial.   
   
   
       2 ) The copper alloy of  claim 1  wherein the balance of substantially Cu also contains up to at least one of:
 0.5% of at least one of the following group which consists of: Sn, Si, Co, Ti, Cr, Fe, Mg, Zr, Ag; and   up to 0.1% of at least one the following group which consists of: P, B, Ca, Ge, Se, Te;   and said alloy has a time to complete inactivation of less than 60 minutes.   
   
   
       3 ) A copper alloy of white visual appearance similar to one of stainless steel and “nickel silver” the copper alloy consisting essentially of:
 a) 6-25% zinc (Zn),   b) 4-17% manganese (Mn),   c) 0.1-2.5% iron (Fe),   d) a balance of substantially Cu   e) wherein the combination of a-d exhibits a white visual appearance and is effectively antimicrobial.   
   
   
       4 ) The copper alloy of  claim 3  wherein the balance of substantially copper also contains at least one of:
 up to 0.5% of at least one of the following group which consist of: Sn, Si, Co, Ti, Cr, Ni, Mg, Zr, Ag, and   up to 0.1% of at least one of the following group consisting of: P, B, Ca, Ge, Se.   
   
   
       5 ) A copper alloy of white visual appearance similar to one of stainless steel and “nickel silver”; the copper alloy consisting essentially of:
 a) 6-25% zinc (Zn),   b) 4-17% manganese (Mn),   c) 0.1-5% nickel (Ni),   d) 0.05-2.5% iron (Fe), and   e) a balance of substantially Cu;   f) where the combination of a-e is effectively antimicrobial and has a white visual appearance.   
   
   
       6 ) The copper alloy of  claim 5  which also contains at least one of:
 up to 0.5% of at least one of the following group which consists of: Sn, Si, Co, Ti, Cr, Mg, Zr, Ag, and   up to 0.1% of at least one of the group consisting of: P, B, Ca, Ge, Se, Te.   
   
   
       7 ) The copper alloy of  claim 1  which combination is resistant to tarnishing on room temperature exposure in air and has a time to complete inactivation of less than 60 minutes. 
   
   
       8 ) The copper alloy of  claim 7  which contains 12-20% Zn, 10-17% Mn, and 0.5-3.5% Ni 
   
   
       9 ) The copper alloy of  claim 8  which contains 13-16% Zn, 14-17% Mn, and 1.5-2.5% Ni, and wherein said time to complete inactivation is less than 20 minutes. 
   
   
       10 ) copper alloy of  claim 1  which contains up to 0.3% Zr by weight. 
   
   
       11 ) The copper alloy of  claim 3  which is effectively antimicrobial and contains Ni only as an impurity. 
   
   
       12 ) The copper alloy of  claim 11  which contains 12-20% Zn, 10-17% Mn, and 0.5-2.5% Fe. 
   
   
       13 ) The copper alloy of  claim 12  which contains 15-18% Zn, 14-17% Mn, and 0.5-1.5% Fe. 
   
   
       14 ) The copper alloy of  claim 5  which is resistant to elevated temperature tarnishing. 
   
   
       15 ) The copper alloy of  claim 14  which contains 12-20% Zn, 10-17% Mn, 0.5-3.5% Ni and 0.1-1.0% Fe. 
   
   
       16 ) The copper alloy of  claim 15  which contains 13-16% Zn, 14-17% Mn, 1.5-2.5% Ni and 0.2-0.6% Fe. 
   
   
       17 ) The copper alloy of  claim 14  which contains at least one of:
 up to 1.0% Al; and   and at least one of:
 up to 0.5% of at least one of the following group consisting of: Sn, Si, Co, Ti, Cr, Mg, Zr, Ag, and; 
 up to 0.1% of at least one of the group consisting of: P, B, Ca, Ge, Se, Te. 
   
   
   
       18 ) A copper alloy of white visual appearance and resistant to touch tarnishing to be used for coinage applications as a direct replacement for C713, the copper alloy comprising:
 a) 6-25% zinc (Zn),   b) 4-17% manganese (Mn),   c) 0.1-9.0% nickel (Ni),   d) a balance of substantially Cu; and   e) said combination of a-d having a white visual appearance, is effectively antimicrobial and has an electrical conductivity greater than 2.5% IACS at eddy current gauge exciting frequencies between 60 kHz and 480 kHz.   
   
   
       19 ) The copper alloy of  claim 18  wherein the balance of substantially Cu also contains up to at least one of:
 0.5% of at least one of the following group which consists of: Sn, Si, Co, Ti, Cr, Fe, Mg, Zr, Ag; and   up to 0.1% of at least one the following group which consists of: P, B, Ca, Ge, Se, Te.   
   
   
       20 ) The copper alloy of  claim 19  wherein said electrical conductivity is between 4% IACS and 7% IACS;
 and further having a time to complete inactivation of less than 60 minutes.   
   
   
       21 ) The copper alloy of  claim 19  containing up to 0.3% Zr by weight; and
 the time to complete inactivation is less than 30 minutes.   
   
   
       22 ) The copper alloy of  claim 21  containing 10-18% Zn, 4-7% Mn, 4-9% Ni and 0.05-0.20% Zr; and
 the time to complete inactivation is less than 20 minutes.   
   
   
       23 ) The copper alloy of  claim 22  which contains 12-16% Zn, 4-6% Mn, 5-9% Ni and 0.05-0.15% Zr; and
 the time to complete inactivation is less than 15 minutes.   
   
   
       24 ) The copper alloy of  claim 18  which has been formed into a planchet.