JPS5871032A - Electrode material for wire cut electric discharge machining - Google Patents

Abstract

PURPOSE:To provide a blank for a wire electrode with satisfactory conductivity and heat resisting property and without work hardening by using a single metal having at least a certain value of purity. CONSTITUTION:A single metal having at least 99.99% of purity is in principle used for a wire electrode blank. For example, electrolytic iron is repeatedly subjected to zone-refining method to improve the purity.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a metal material suitable as a wire electrode material for a wire-cut electrical discharge machining device.

This wire electrode material must be easy to draw,
It has good conductivity, high processing speed and low consumption ratio when used as an electrode, good heat resistance, especially when the tensile strength does not deteriorate at high temperatures, and is difficult to cut during use. It is required to have properties such as being difficult to peel off and being able to perform processing at locations where the wire electrode is wound or bent for two-dimensional processing or eight-dimensional processing.

In particular, in order to perform wire cutting processing reliably and quickly, K is used to obtain fine wires with good mechanical strength and conductivity, and to harden the electrodes by hardening.
It is also important that the discharge stain or wire electrode is rarely cut during processing by bending it during use, that is, it is difficult to cut. - For this reason, pure copper or a copper alloy such as brass is generally used as an electrode material, and copper alloys to which suboxide steel is added have also been proposed.

Copper electrodes have a good value in terms of electrical conductivity, but the wear ratio is around 60%, and they are also insufficient in terms of mechanical strength and heat resistance. It is superior to FI steel wire in terms of electrical conductivity and wear ratio. Since hard copper has superior tensile strength and hardness, i.e., springiness, it tends to remain curly, and unless the guides are moved with sufficient tension between them, they will not move in a straight line. The problems of machining accuracy and wire breakage were contradictory.

On the other hand, 9 alloy wire, which is made by mixing pure copper with 1-6 grams of cuprous oxide C11,0, has a conductivity that is not much different from pure copper and a consumption ratio of 20 to 80.
1, and the processing speed is excellent, but there is still a problem with the difficulty of cutting.

Ω On the other hand, 0.1■ tungsten, molybdenum, or 7-alloy
- There is a wire electrode 4 drawn below, but because it is expensive, it is only used for special purposes.

In addition, wire-cut electric discharge machining equipment moves the wire electrode from one reel to the other reel and performs pulse discharge while supplying machining fluid to machine the desired shape by electric discharge machining. The wire electrode is twisted and bent each time it passes between the brake roller and the pinch roller, between the capstan and the pinch roller, between the guide roller and the guide guide, etc., and this causes the wire electrode to work harden, resulting in a loss of linearity. If you try to process a damaged part or a part where the wire electrode is strongly bent, it will be impossible to obtain a small bending radius.
Therefore, there is a problem in that it is impossible to process the contours of overhanging parts, such as the hoe part of an extrusion die or the cutting edge part of a trim die.

The present invention has been made based on the above-mentioned viewpoints, and the object thereof is to have good electrical conductivity and heat resistance, and have a low recrystallization temperature so that work hardening does not occur or remain. An electrode material for wire electrodes that can obtain a small bending radius when processing the electrode by bending it, and can also be used by winding it, and it is rarely cut during use. There is a struggle to provide this.

The gist of the present invention is to use a single metal having a purity of 99.991 or higher as a wire electrode material.

If the purity of the iron or steel used for the wire electrode is about 99.99 or higher, the recrystallization temperature will be lowered and work hardening will not occur or remain.

However, according to experiments, the purity of commonly used electrolytic iron is approximately 99J9211 at its best, and work hardening occurs when this is used as an electrode. Note that this electrolytic iron contains the following impurities.

Electrolytic iron carbon 0.006~0.021s Silicon 0.002~0.011g
0.009～
O,OS*Sulfur 0.002~0.0
0911G Then, for this electrolytic iron, Zo, n
By repeating the e-Refining method several times and refining, a highly pure iron material could be obtained.

Examples are shown below.

[Example 1] When the Zone-R@finin''g method was applied to electrolytic iron by repeating it 8 times to increase its purity, impurities were significantly reduced as shown below.

- element 0.00411G silicate: ry o, ooogn phosphorus o, oos*sulfur
Yellow 0.0008 cm Total 0.00791 Purity 99.992111! [Example 2] Purity obtained in Example 1 above was 99.99! i! 1
1s of iron is further made smaller in the width of Zon in a vacuum, and 1
As a result of repeating the treatment eight times using the ZOn-Refining method, an extremely high quality iron material with a purity of 99.99986 or better could be obtained. .

Zinc was mechanically plated on the surface of the iron material obtained as in Example 1 above, and the wire electrode was used with a diameter of approximately 0.22 mm, with a tension of 60 (l) between the guides. This electrode The discharge pulse was turned on for 4u'-1τof/9us, and the specific resistance of the machining fluid was set to 'l 2
I put 1tttat eggplant on 1LD material. This combination 8.8■/
- speed of machining feed was possible. Compared to the case of using conventional zinc-copper alloy electrodes, this improves the machining speed by 90%, maintains good linearity with small applied tension, and prevents large distortions in the upper and lower arms, etc. Since there is no need to apply pressure, the reproducibility of machining accuracy has improved.

Since the present invention is configured as described above, according to the present invention,
Since the electrode does not work harden, a small bending radius can be obtained when machining by bending the wire electrode. Therefore, it is possible to obtain a small bending radius when machining by bending the wire electrode. For example, it is possible to process the contour shape of the hollow part of an extrusion die or the cutting edge part of a trim die, and the electrode is not prone to curling, has a low consumption ratio, and is easy to work with since there is almost no cutting during use. The efficiency of the system will be greatly improved.

Note that the present invention is not limited to the embodiments described above. That is, for example, in this example, the KZ On-Refining method is used to increase the purity of electrolytic iron, but it is also possible to use other known methods. Footings are not limited to mechanical coating, but can also include molten plating, electroplating, chemical plating,
Alternatively, ion blasting, sputter coating, etc. are also possible.The coating metal is not limited to zinc, but may be other known metals, such as C6, In, or Mg, preferably.

It is possible to use metals such as 8n, Pb, Bi, etc. or alloys thereof, which have a high vapor pressure and easily evaporate into the machining fluid, and the present invention does not encompass all of them. be.

In addition, the room temperature in the room where the wire-cut electrical discharge machined material is installed and moved may be set to a predetermined temperature above room temperature, for example 80°C.
Processing may be carried out while blowing hot air to the mounting path of the wire electrode, or some guide rollers in the mounting path of the wire electrode may be heated with a four-wheeler, etc. to ensure purity that the recrystallization temperature of the wire electrode is higher than room temperature. It is possible to use the following electrode material metals.

Patent applicant Inoue Japax Research Institute Agent (7524”) Shotabe Mogami

Claims (1)

[Claims] 1) Made from a single metal with a purity of 9949- or higher*
An electrode material for wire cut electric discharge machining characterized by the following. The electrode material for wire-cut electric discharge machining according to claim 1, wherein the single metal is iron. 8) The electrode material for wire-cut electric discharge machining according to claim 1, wherein the single metal is copper. 4) The electrode material for wire-cut electric discharge machining according to claim 1, 2, or 8, wherein the surface of the material is mechanically coated with zinc.