ELECTRODE WIRE FOR ELECTRIC DISCHARGE MACHINING AND ITS MANUFACTURE

摘要

PROBLEM TO BE SOLVED: To suppress the occurrence of metal powder waste caused by falling of aβphase by reducing the concentration of Zn in the surface of a wire rod to a specific wt.%. SOLUTION: A Cu-Zn alloy wire rod 2 including Zn not less than 39 wt.% and less than 45 wt.% is fed from a payoff 3 and passed through an electric furnace 4 in an inert gas atmosphere such as N2, Ar and introduced into a cooling tank 5. The heat treatment can reduce the concentration of Zn on the surface of the wire rod 2 not less than 10 wt.% and less than 38 wt.%. This constitution can eliminate theβphase on the surface so as to form a surface part composed of only anαphase. When the concentration of the Zn reaches less than 10 wt.%, the wire rod 2 is easily fusion cut at the heat treatment temperature for decreasing the Zn concentration on the surface of the wire rod 2. When exceeding 38 wt.%, the generation of waste on the surface of the wire rod 2 is increased. The thickness of the region with the Zn concentration decreased is set to less than 10μm.