Continuously Cast Mg Brass

Abstract

A quantity of continuously cast Mg brass is made by the step of melting a charge of Mg brass and then continuously casting a rod of the Mg brass through a casting die. The casting die has been previously treated by continuously casting a melt of copper or brass through it to clean out Mg deposits formed by an earlier continuous casting of Mg brass which formed the Mg deposits. The quantity of continuously cast Mg brass may be in the form of EDM wire.

We claim: 
     
         1 . A quantity of continuously cast Mg brass made by a method comprising the steps:
 a) in a melting furnace, melt a first charge of Mg brass to form a first melt of Mg brass comprising:
 i) zinc at a first zinc concentration of about 35 wt %; 
 ii) magnesium at a first magnesium concentration in the range of 0.02 wt % to 5 wt %; and 
 iii) copper at a first copper concentration in the range of 60 wt % to 65 wt %; 
   b) transfer said first melt of Mg brass to a holding furnace comprising a casting die suitable for continuously casting a rod; and   c) continuously cast a first rod of Mg brass through said casting die   
       wherein said casting die has been previously treated by a method comprising the steps:
 d) continuously cast a prior melt of Mg brass through said casting die such that deposits comprising Mg are formed thereupon; and 
 e) continuously cast a prior melt of either copper or brass through said casting die such that said deposits comprising Mg are removed from said casting die. 
 
     
     
         2 . The quantity of continuously cast Mg brass of  claim 1  wherein said casting die is a coated graphite die. 
     
     
         3 . The quantity of continuously cast Mg brass of  claim 2  wherein said coating comprises phenolic resin or phosphorus. 
     
     
         4 . The quantity of continuously cast Mg brass of  claim 1  wherein said first charge of Mg brass comprises at least a portion of said prior melt of copper or brass after it has been cast through said casting die. 
     
     
         5 . The quantity of continuously cast Mg brass of  claim 1  wherein said first magnesium concentration is in the range of 0.05 wt % to 0.5 wt %. 
     
     
         6 . The quantity of continuously cast Mg brass of  claim 1  wherein said quantity of continuously cast Mg brass consists essentially of copper, zinc, magnesium, and unavoidable impurities. 
     
     
         7 . The quantity of continuously cast Mg brass of  claim 1  wherein said step of continuously casting said first rod of Mg brass through said casting die is a step of horizontally continuously casting said first rod of Mg brass through said casting die. 
     
     
         8 . The quantity of continuously cast Mg brass of  claim 1  wherein said steps further comprise the step:
 a) draw said first rod of Mg brass through one or more drawing dies to form a quantity of Mg brass EDM wire. 
 
     
     
         9 . The quantity of continuously cast Mg brass of  claim 8  wherein said steps further comprise the step:
 a) coat said first rod of Mg brass with a coating comprising copper, zinc or alloys thereof.