Patent ID: 8822872

Claim:
An electrode wire for electro-discharge machining, the electrode wire comprising: a core wire including a first metal, the core wire having a smooth surface; a first alloy layer formed at a boundary region between the core wire and a second metal plated on an outer surface of the core wire due to mutual diffusion between the core wire and the second metal; and a second alloy layer formed at an outer portion of the first alloy layer due to diffusion of the first metal to the second metal, the second alloy layer having a plurality of cracks therein, the plurality of cracks being formed by twisting the wire with a plurality of rollers, wherein a core wire material is erupted onto a surface of the electrode wire for electro-discharge machining, which includes at least the core wire, the first alloy layer, and the second alloy layer, along the cracks appearing on the second alloy layer, so that a plurality of grains are formed on the surface of the electrode wire, a length of a grain in the circumferential direction being more than twice a width of the grain, and wherein the grain including at least the core wire material and a second alloy material is distributed onto the surface of the electrode wire for electro-discharge machining.