JPH08176707A - Electrode wire for wire electric discharge machining - Google Patents

Abstract

PURPOSE: To impart the excellent electric discharge machining characteristics and automatic wire connection by specifying the composition of a copper alloy used for an electrode wire. CONSTITUTION: The alloy composition, by wt.%, is such that Zn is 34 to 45%, that at least more than one selected from a group composed of Bi, Fe, Mg, Mn, Te, P and In is a total of 0.005 to 1.5% as an additional element, and that the balance is Cu with inevitable impurities. Desirably, the added amounts X of at least more than one element selected from a group consisting of additional elements of Bi, Fe, Mg, Mn, Te, P and In is within a range indicated as the equation I, provided that Y in the equation I is the Cu contents (%) in the alloy. Further, it is desirable that the strength ratio at 200 deg.C (tensile strength at 200 deg.C)/(tensile strength at room temperature)×100(%) is less than 40 to 90%. In machining for an electrode wire, the cold draft of the final process is made 75 to 99.9%, and the wire is finished with a diameter <0.1mm.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrode wire used for wire electric discharge machining.

[0002]

2. Description of the Related Art In wire electric discharge machining, an intermittent electric discharge is generated between a linear machining electrode called a wire electric discharge machining electrode wire and a workpiece through a machining liquid such as water or oil. However, it is a method of melting and cutting the workpiece into a desired shape by moving the workpiece relative to the wire electric discharge machining electrode wire. This method is used for manufacturing various molds. In such wire electrical discharge machining, the electrical discharge machining characteristics such as the finish of the work piece, the machining accuracy and the finished surface state are good, the electrode wire does not adhere to the work piece, and the electric discharge machining time is short. Is required. As an electrode wire for electric discharge machining used for such wire electric discharge machining, a brass wire has been conventionally used because it has excellent wire drawing machinability and strength as an electrode wire.

[0003]

Recently, an electrode wire capable of improving the electric discharge machining speed has been demanded as the machining power source is improved. In particular, an electrode wire capable of increasing the electric discharge machining speed is desired when a power source of a wire electric discharge machine that applies a high voltage and a short-time pulse voltage is used. However, it was not possible to obtain a sufficiently high EDM speed with the conventional EDM electrode wire using a brass wire. In addition, the amount of electrode wires attached to the work piece is large, and there is a drawback that the wires are easily broken when attempting electrical discharge machining at high speed. An object of the present invention is to provide an electrode wire for wire electric discharge machining which can shorten the electric discharge machining time and which is hard to attach the electrode wire to a workpiece.

[0004]

The present invention has a Zn content of 34 to 45.
An electrode wire for wire electric discharge machining containing brass as a main component, wherein said brass is Bi, Fe, Mg, Mn, Te,
At least one element selected from the group consisting of P and In as the total of additive elements is 0.005% by weight or more and 1.
It is characterized in that the content is 5% by weight or less. Desirably Bi, Fe, Mg, Mn, T
It is preferable that the addition amount X of at least one element selected from the group consisting of e, P, and In be within the range represented by the following formula. ^{(100-Y) 2/200000} ≦ X ≦ (100-Y) 2 /
10000 (where Y =% by weight of Cu contained in the electrode wire for wire electric discharge machining)

Furthermore, it is preferable that the main component is brass with a Zn content of 35 to 43% by weight. 200 ° C in this invention
It is preferable that the strength ratio ((tensile strength at 200 ° C.) / (Tensile strength at room temperature) × 100 (%)) in 40% or more and less than 90%. Also,
A wire electric discharge machining electrode wire having a cold working degree of 75% or more and less than 99.9% in the final step of manufacturing the wire electric discharge machining electrode wire is preferable. Further, in the present invention, the wire diameter is 0.1
The electrode wire for wire electrical discharge machining of less than mm also shows excellent performance.

[0006]

When brass having a Zn content of less than 34% by weight is used, epoch-making improvement in the electric discharge machining speed is not seen as compared with the conventional material, while brass having a Zn content of more than 45% by weight is used. If it is used, processing into a wire becomes difficult. Therefore, the present inventors used brass having a Zn content of 34 to 45% by weight, and adding various elements to the brass to add the additive element and the machinability of the wire and the electrical discharge machining characteristics (machining speed, surface texture and The relationship of (automatic connection, etc.) was investigated. As a result, Z
When the content of n is 34 to 45% by weight of brass, Bi, F
A total of at least one element selected from the group consisting of e, Mg, Mn, Te, P and In is 0.05 to 1.5.
It was found that when added by weight%, not only the processing into a wire is possible, but also the electric discharge machining speed is improved as compared with the case where no addition is made and the surface properties become smooth. Here, the total addition amount is set to be 0.05 to 1.5% by weight because if it is less than 0.05%, the effect of improving the electric discharge machining characteristics is small, and if it exceeds 1.5% by weight, the workability to the wire is adversely affected. To give. Bi, Fe, Mg, Mn, T
The additive amount of at least one element selected from the group consisting of e, P, and In is (100-Y) ² / 200,000 or more (100-Y) ² / 10,000 or less (where Y = electrode wire for wire electric discharge machining) is to that the content by weight%) of Cu, if the amount added is (less than 100-Y) ^2/200000, less effect of improving the discharge machining characteristics, (100-Y) ² /
This is because the effect is saturated when it exceeds 10,000. Further, more preferably, the main component is brass having a Zn content of 35 to 43% by weight.

The reason why the Zn content is 35 to 43% by weight is that the degree of improvement in the electric discharge machining characteristics and the ease of processing into a wire are balanced, and if the content is less than 35% by weight, the electric discharge is reduced. This is because there is little improvement in the processing characteristics, and if it exceeds 43% by weight, processing into a wire becomes somewhat difficult. In the electrode wire for wire electric discharge machining, 2
Strength ratio at 00 ° C ((tensile strength at 200 ° C) / (tensile strength at room temperature) x 100 (%)) is 4
It has been found that when the content is 0% or more and less than 90%, the electrical discharge machining characteristics are remarkably improved. When it was less than 40%, no marked improvement in the electric discharge machining characteristics was observed, and when 90% or more was not present in the wire electrode for wire electric discharge machining.

Further, when the relationship between the cold working degree in the final step of manufacturing the electrode wire for wire electric discharge machining and the electric discharge machining characteristics was investigated, the cold working degree in the final step of manufacturing the electrode wire for wire electric discharge machining was 75. % And less than 99.9%, it was found that the electric discharge machining characteristics were remarkably improved. The reason why the cold working degree in the final step is 75% or more and less than 99.9% is that the electrical discharge machining characteristics are not significantly improved at less than 75% and 99.9%. Furthermore, in the electrode wire for wire electric discharge machining, the smaller the wire diameter, the better the surface quality of the surface to be machined. However, conventional materials cannot be said to have sufficient electric discharge machining characteristics when the wire diameter is less than 0.1 mm. On the other hand, in the electrode wire of the present invention,
Excellent electrical discharge machining characteristics were exhibited even when the wire diameter was less than 0.1 mm.
The electrode wire according to the present invention can perform electric discharge machining at a high speed, and exhibits excellent electric discharge machining characteristics such as a small amount of deposits on a workpiece. In particular, this electrode wire exhibits excellent electric discharge machining characteristics in electric discharge machining in which a high voltage and a short-time pulse voltage are applied.

[0009]

[Example] Zn and Ge, Sb, Ti, Mn, Al, Si, Mg, In,
An alloy material having the composition shown in Table 1 was obtained by adding at least one element selected from the group consisting of P, Fe, B, Ni and Sn and continuously casting. The composition in Table 1 shows% by weight.

[0010]

[Table 1]

This Cu alloy material was hot extruded to a diameter of 8
After making a rough wire of mmΦ and stripping, wire drawing and heat treatment were repeated to manufacture an electrode wire having a desired wire diameter. Also, in order to eliminate the wire habit, a light electric current heat treatment was performed at the final stage of the wire drawing process. When processing to this desired wire diameter,
The required number of heat treatments was shown as workability. The smaller the number of heat treatments, the better the workability. Among the electrode wires thus obtained, the electrode wire according to the present invention had high strength and was excellent in straightness with no line habit.

The obtained electrode wire is attached to a wire electric discharge machine and electric discharge machining is performed under the same conditions. The electric discharge machining speed, the amount of adhesion to the work piece, the surface texture of the work piece, the disconnection state of the electrode wire, and the automatic The connectivity was investigated. The results are the workability described above and the specific strength at 200 ° C. ((tensile strength at 200 ° C.) / (Tensile strength at room temperature) × 100.
(%)) And shown in Table 2. Further, for comparison, the same investigation was conducted on the conventional electrode wire, and the results are also shown in Table 2.
The electric discharge machining speed is calculated by the machining cross-sectional area per unit time (the product of the machining feed speed and the workpiece thickness), and then the respective ratios are calculated with the wire EDM speed of the conventional material being 1.0. It was shown to. The adhered amount of the work piece was also shown as a relative ratio with the conventional wire being 100.

[0013]

[Table 2]

The electrical discharge machining characteristics and machinable surface properties in Table 2 are as follows. A: The surface was very smooth and was very good with no dimensional difference in the thickness direction. B: The surface was smooth and there was almost no dimensional difference in the thickness direction, which was good. C: The surface was slightly rough, and a slight dimensional difference was observed in the thickness direction. D: The surface was rough, and a Tyco-like shape was shown in the central portion in the thickness direction.

[0015]

As described above, it can be said that the electrode wire according to the present invention has remarkably improved electric discharge machining characteristics (machining speed, surface property, etc.) and has excellent automatic wire connection property. Further, when the examples shown in Table 2 and the comparative examples are compared, outside the scope of the present invention, machinability, discharge characteristics,
It can be seen that it is difficult to satisfy all and the automatic connection properties at the same time.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Kenji Miyazaki, 1-3 Shimaya, Konohana-ku, Osaka City, Osaka Prefecture Sumitomo Electric Industries, Ltd. (72) Inventor, Taichiro Nishikawa, Shimanoichi, Konohana-ku, Osaka City, Osaka 1 to 3 Sumitomo Electric Industries, Ltd. Osaka Works

Claims (6)

[Claims] 1. Zn in an amount of 34% by weight or more and 45% by weight or less and Bi, Fe, Mg, Mn, Te, and
At least one element selected from the group consisting of P and In as the total of additive elements is 0.005% by weight or more and 1.
An electrode wire for wire electric discharge machining, which is contained so as to satisfy a range of 5% by weight or less, and the balance is copper and inevitable impurities. 2. Bi, Fe, Mg, Mn, Te, P, I
The electrode wire for wire electric discharge machining according to claim 1, wherein an addition amount X (wt%) of at least one element selected from the group consisting of n is within a range represented by the following formula. However, if the content of Cu wire electric discharge machining electrostatic curve was Y ^{weight%, (100-Y) 2} /200000 ≦ X ≦ (100-Y) 2 /
10,000 3. The electrode wire for wire electric discharge machining according to claim 1, wherein the main component is brass having a Zn content of 35 to 43% by weight. 4. Strength ratio at 200 ° C. ((tensile strength at 200 ° C.) / (Tensile strength at room temperature) × 100
(%)) Is 40% or more and less than 90%, The electrode wire for wire electric discharge machining according to claim 1. 5. The cold workability of the final step is 75% or more,
The electrode wire for wire electric discharge machining according to claim 1, which has a content of less than 99.9%. 6. The electrode wire for wire electric discharge machining according to claim 1, wherein the wire diameter is less than 0.1 mm.