Method for making Mg brass EDM wire
A method for making Mg brass EDM wire has the steps of melting a charge of Mg brass to form a melt of Mg brass; transferring the melt to a holding furnace; casting a rod from the melt; and drawing the rod down to a size suitable for EDM machining. Mg deposits may form in the holding furnace. These can be removed by flushing the holding furnace with molten brass.
1. A method for making Mg brass EDM wire 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 in the range of 5 wt % to 50 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 45 wt % to 95 wt %;
b) transfer said first melt of Mg brass to a holding furnace comprising a casting die suitable for continuously casting a rod;
c) continuously cast a first rod of Mg brass through said casting die thereby forming deposits comprising Mg on said casting die;
d) draw said first rod of Mg brass through one or more drawing dies to form a quantity of said Mg brass EDM wire;
e) after said first rod of Mg brass is cast, melt a charge of copper or brass in said melting furnace to form a melt of flushing metal, said melt of flushing metal being operable to dissolve said deposits;
f) transfer said melt of flushing metal to said holding furnace; and
g) cast a rod of flushing metal from said holding furnace such that said deposits are substantially removed from said casting die.
2. The method of claim 1 wherein said first zinc concentration is about 35 wt % and said first magnesium concentration is in the range of 0.02 wt % to 5 wt %.
3. The method of claim 1 wherein said first zinc concentration is about 35 wt % and said first magnesium concentration is in the range of 0.05 wt % to 0.5 wt %.