Low lead ingot

Abstract

A composition for a low lead ingot comprising primarily copper and including tin, zinc, sulfur, phosphorus, nickel. The composition may contain manganese. The low lead ingot, when solidified, includes sulfur or sulfur containing compounds such as sulfides distributed through the ingot. The presence and a substantially uniform distribution of these sulfur compounds imparts improved machinability and better mechanical properties.

1 . An alloy composition comprising:
 a copper content of about 83% to about 91%;   a sulfur content of about 0.1% to about 0.8%;   a tin content of about 2.0% to about 4.0%;   a lead content of less than about 0.09%;   a zinc content of about 4.0% to about 14.0%; and   a nickel content of about 1.0% to about 2.0%   
     
     
         2 . The alloy composition of  claim 1  further comprising less than 0.1% iron. 
     
     
         3 . The alloy composition of  claim 1  further comprising less than 0.02% antimony. 
     
     
         4 . The alloy composition of  claim 1  further comprising about 0.05% phosphorus. 
     
     
         5 . The alloy composition of  claim 1  further comprising about 0.005% aluminum. 
     
     
         6 . The alloy composition of  claim 1  further comprising less than 0.005% silicon. 
     
     
         7 . The alloy composition of  claim 1  further comprising about 0.01% and about 0.7% manganese. 
     
     
         8 . The alloy composition of  claim 1  further comprising about 0.2% zirconium. 
     
     
         9 . The alloy composition of  claim 1  further comprising about 0.2% boron. 
     
     
         10 . The alloy composition of  claim 1  further comprising about 0.1% and about 0.7% manganese. 
     
     
         11 . An alloy composition comprising:
 a copper content of about 86% to about 89%;   a sulfur content of about 0.1% to about 0.8%;   a tin content of about 7.5% to about 8.5%;   a lead content of less than 0.09%;   a zinc content of 1.0% to about 5.0%; and   a nickel content of about 1.0%.   
     
     
         12 . The alloy composition of  claim 1  further comprising less than 0.02% to about 0.2% iron. 
     
     
         13 . The alloy composition of  claim 1  further comprising about 0.02% antimony. 
     
     
         14 . The alloy composition of  claim 1  further comprising about 0.05% phosphorus. 
     
     
         15 . The alloy composition of  claim 1  further comprising about 0.005% aluminum. 
     
     
         16 . The alloy composition of  claim 1  further comprising less than 0.005% silicon. 
     
     
         17 . The alloy composition of  claim 1  further comprising about 0.1% and about 0.7% manganese. 
     
     
         18 . The alloy composition of  claim 1  further comprising about 0.2% zircon. 
     
     
         19 . The alloy composition of  claim 1  further comprising about 0.2% boron. 
     
     
         20 . The alloy composition of  claim 1  further comprising about 0.1% and about 0.7% manganese. 
     
     
         21 . A method for producing a copper alloy of  claim 1 , comprising:
 heating a base ingot to a temperature of about 2,100 degrees Fahrenheit to form a melt;   ceasing heating of the melt and plunging additives, except for sulfur, into the melt between 15 to 20 seconds;   skimming at least a partial amount of slag from the melt;   heating the melt to a temperature of about 2,140 Fahrenheit;   ceasing heating of the melt and plunging the sulfur into the melt;   heating the melt to a temperature of about 2,150 degrees Fahrenheit; and   removing slag from the melt.   
     
     
         22 . The method of  claim 21 , further comprising placing graphite on the bottom of a crucible prior to heating the base ingot in the crucible. 
     
     
         23 . The method of  claim 22 , wherein the crucible is heated using a gas-fired furnace. 
     
     
         24 . The method of  claim 22 , wherein the crucible is heated using an induction furnace and wherein the melt undergoes inductive stirring. 
     
     
         25 . The method of  claim 21 , further comprising plunging phosphorus into the melt after the plunger of the sulfur.