| 摘要 |
PURPOSE:To obtain a composite electrode-wire having the superior electric discharge characteristic by covering the outer periphery of a brass wire by the material containing Zn as main constituent in the stage of the wire diameter thicker than the final wire diameter and carrying-out working with a surface reduction rate of 50% or more at a temperature below the recrystallization temperature of the covering material and higher than the room temperature. CONSTITUTION:A surface reduction rate of 50% is the min. necessary working degree for securing the close adhesion performance. At a temperature lower than the room temperature, the above-described close adhesion performance is not improved, and when the temperature rises over the recrystallization temperature of a covering material, the workability of the covering material is deteriorated, and the strength of a core member is reduced or can not be improved. A die having an approach angle of 10 deg. or less is used in the above-described working. The reason in that the wire extension performance can be improved, and the close adhesion performance between the core member and the covering member during wire extension can be improved. Brass wire, e.g., the alloy wire containing 70-60% Cu and 30-40% Zn and the alloy added with addition elements (Sn, Al, etc.) are used as the core member. Highly pure Zn containing Zn in 99.9% or more is used as the material containing Zn as main constituent. |
