METHOD FOR THE PRODUCTION OF POROUS ELECTRODE WIRE FOR ELECTRODE MACHINERY AND STRUCTURE OF THE ELECTRODE WIRE

Abstract

Method for producing a coated electrode wire for use in electrical discharge machining, comprising: Providing a central wire having a first diameter and formed from a first copper-containing metal, Hot-dip coating of the central wire for a desired time and at a desired temperature through a melt bath containing a second metal having an evaporation temperature lower than that of the first metal, wherein an alloy layer is formed on the central wire by means of a diffusion reaction between the first metal and the second metal, which has greater hardness and lower elongation than the first metal and the second metal, and wherein a coating layer is formed on the alloy layer, and Drawing the central wire, which has the alloy layer and the coating layer, so that a coated electrode wire with a second diameter is formed, whereby cracks are formed during the drawing step due to the high hardness and low elongation in the alloy layer and in the coating layer, characterized in that the resulting alloy layer and the resulting coating layer are porous with a sponge-like structure.

Description

[0001] Regarding European patent 0 930 131 (DE 698 33 944), the 7th Senate (Voidance Senate) of the Federal Patent Court, based on the oral proceedings of November 18, 2025, has ruled as follows: I. European patent 0 930 131 is hereby declared invalid with effect for the territory of the Federal Republic of Germany to the extent of claims 14 to 18.

Claims

[1] Method for producing a coated electrode wire for use in electrical discharge machining, comprising: Providing a central wire having a first diameter and formed from a first copper-containing metal, Hot-dip coating of the central wire for a desired time and at a desired temperature through a melt bath containing a second metal having an evaporation temperature lower than that of the first metal, wherein an alloy layer is formed on the central wire by means of a diffusion reaction between the first metal and the second metal, which has greater hardness and lower elongation than the first metal and the second metal, and wherein a coating layer is formed on the alloy layer, and Drawing the central wire, which has the alloy layer and the coating layer, so that a coated electrode wire with a second diameter is formed, whereby cracks are formed during the drawing step due to the high hardness and low elongation in the alloy layer and in the coating layer, characterized by that the resulting alloy layer and the resulting coating layer are porous with a sponge-like structure. [2] Method according to claim 1, further comprising heat treatment of the coated electrode wire having the second diameter to stabilize its mechanical properties. [3] Method according to claim 1, wherein the first metal is formed of brass. [4] Method according to claim 3, wherein the second metal comprises zinc, aluminium, tin or alloys thereof. [5] Method according to claim 4, wherein the desired time enables the formation of the coating layer of 3-10 µm on the central wire. [6] Method according to claim 1, wherein the second metal comprises zinc, aluminium, tin or alloys thereof. [7] Method according to claim 6, wherein the desired time enables the formation of the coating layer of 3-10 µm on the central wire. [8] Method according to claim 1, wherein the desired time enables the formation of the coating layer of 3-10 µm on the central wire. [9] Method according to claim 1, further comprising removing the coating layer formed on the central wire. [10] Method according to claim 9, wherein the first metal is formed of brass. [11] Method according to claim 9, wherein the second metal comprises zinc, aluminium, tin or alloys thereof. [12] Method according to claim 11, wherein the desired time enables the formation of the coating layer of 3-10 µm on the central wire. [13] Method according to claim 9, wherein the desired time enables the formation of the coating layer of 3-10 µm on the central wire. [14] void [15] void [16] void [17] void [18] void