JP3430582B2 - Electrode wire for wire electric discharge machining - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wire electric discharge machining electrode wire, and more particularly, to an electric discharge machining electrode wire using a brass wire, which has a thin wire diameter obtained by cold machining and which has excellent electric discharge machining characteristics. Regarding excellent electrode wires.

[0002]

2. Description of the Related Art Recently, an electrode wire capable of improving an electric discharge machining speed has been desired with the improvement of a machining power source. In particular, in a wire electric discharge machine, an electrode wire capable of increasing the electric discharge machining speed is desired when a high voltage and a short-time pulse voltage are applied.

However, it has been impossible to obtain a sufficiently high electric discharge machining speed with the conventional electrode wire for electric discharge machining using a brass wire. In addition, the amount of electrode wires attached to the work piece is large, and there is a drawback in that the wire is easily broken when attempting high-speed electrical discharge machining.

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 difficult for a workpiece to adhere to the electrode wire.

[0005]

The present invention relates to a wire electric discharge machining electrode wire comprising a brass containing 60 to 65% by weight of Cu as a main component, wherein the brass contains 0.01 to Al.
Contains 0.09% by weight (tensile strength at 200 ° C /
Calculated as (tensile strength at 25 ° C) x 100 (%)
The strength ratio is 60% or more and less than 90% .

[0006]

The electrode wire of the present invention preferably has a tensile strength of 90 kg / mm ² or more and a ratio of 0.2% proof stress to tensile strength of 0.85 to 0.95.

Further, in the present invention, wire drawing to a wire diameter of 0.1 mm or less can be easily performed.

[0009]

When brass having a Cu content of more than 65% is used, the electric discharge machining speed is inferior and the amount of adhesion to the workpiece is large.
In electric discharge machining, the surface characteristics of the work cannot be made good. On the other hand, when brass having a Cu content of less than 60% is used, it becomes difficult to perform cold wire drawing, and thus a special processing step is required in wire production.
The cost increases.

Therefore, the present inventors have found that the Cu content is 6
Using 0 to 65% brass, various elements were added thereto, and the relationship between the added elements and the cold wire drawing workability and the electric discharge machining characteristics (working speed, surface properties, etc.) was investigated. As a result, when 0.01 to 0.09% by weight of Al is added to brass having a total amount of Cu of 60 to 65% by weight, not only cold drawing of this material is possible, but also It has been found that the electric discharge machining speed of the electrode wire obtained by processing the material is also improved as compared with the case where Al is not added, and the surface property of the workpiece is smooth. A
The addition amount of 1 is 0.01 to 0.09% by weight,
This is because if it is less than 0.01% by weight, the effect of improving the electric discharge machining characteristics is small, and if 0.09% by weight or more is added, the cold workability is adversely affected.

In the electrode wire for wire electric discharge machining of the present invention, the strength ratio obtained by (tensile strength at 200 ° C./tensile strength at 25 ° C.) × 100 (%) is 60%.
It has been found that when the content is less than 90%, the electrical discharge machining characteristics of the obtained electrode wire are particularly improved. When the strength ratio is less than 60%, no marked improvement in the electric discharge machining characteristics is observed, while the strength ratio of 90% or more cannot be obtained in the electrode wire according to the present invention.

In many electrode wires according to the present invention, the tensile strength is 90 kg / mm ² or more, and the ratio of 0.2% proof stress to tensile strength is 0.85 to 0.95. The electrode wire satisfying these values is excellent especially in automatic connection.

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, it is difficult to draw a wire having a diameter of 0.1 mm or less with a conventional material, and it is difficult to obtain an electrode wire having a diameter smaller than this wire diameter. On the other hand, in the present invention, the wire diameter is 0.
An electrode wire having a diameter of 1 mmφ or less could be easily obtained by wire drawing, and the obtained electrode wire showed excellent electric discharge machining characteristics.

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 that the electrode wire does not adhere to the 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.

[0015]

EXAMPLE A Cu alloy material having the composition shown in Table 1 was obtained by adding Zn and Al to an ordinary Cu ingot melted and continuously casting. The Cu alloy material was hot extruded into a wire having a diameter of 8 mmφ, stripped, and then wire drawing and heat treatment were repeated to produce 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. Note that the amount of wire drawing (kg / time) until one wire break was shown as cold workability when processing to a desired wire diameter. That is, the greater the amount of wire drawing work up to one break, the better the cold workability. In the electrode wire thus obtained, the electrode wire within the range of the present invention has a small decrease in strength and a tensile strength of 100 kg / mm ² or more,
It was also excellent in straightness with no habit.

The electrode wire obtained for each alloy material 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, and the surface texture of the work piece. And the disconnection condition of the electrode wire was investigated. The results are shown in Table 2 together with the diameter of the tested electrode wire, the cold workability described above, and the strength ratio = (tensile strength at 200 ° C./tensile strength at 25 ° C.) × 100 (%). Further, for comparison, a conventional electrode wire made of brass was also similarly investigated and shown in Table 2. Regarding the electric discharge machining speed, after obtaining the machining sectional area per unit time (the product of the machining feed rate and the workpiece thickness), the respective machining rates by the conventional electrode wire are set to 1.0, and the respective ratios are obtained. It was shown to. The adhesion amount of the work piece was also shown as a relative value with the conventional wire being 100.

Further, the material Nos. 1 to 13 shown in Table 2
Table 3 shows the tensile strength, the 0.2% proof stress, the ratio of the 0.2% proof stress to the tensile strength, and the evaluation of the automatic wire connection property.

[0018]

[Table 1]

[0019]

[Table 2]

[0020]

[Table 3]

[0021]

As described above, the electrode wire according to the present invention has improved cold-workability, improved electrical discharge machining characteristics (machining speed, surface properties, etc.) compared to conventional ones, and automatic wire connection property. It can be said that it is also excellent. Also, Table 2
When comparing the examples shown in Table 3 with the comparative examples, it is understood that it is difficult to satisfy all of the cold workability, the discharge characteristic, and the automatic wire connection property at the same time outside the scope of the present invention.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Taichiro Nishikawa 1-3-1 Shimaya, Konohana-ku, Osaka City Sumitomo Electric Industries, Ltd. Osaka Works (72) Inventor Tadanori Sano 1-3-1 Shimaya, Konohana-ku, Osaka City No. Sumitomo Electric Industries, Ltd. Osaka Works (56) Reference JP-A-3-236431 (JP, A) JP-A-62-134144 (JP, A) JP-A-59-14430 (JP, A) JP-A-SHO 56-91308 (JP, A) JP-A-2-179857 (JP, A) JP-A-60-127924 (JP, A) JP-A-3-17239 (JP, A) JP-A-61-2227 (JP, A) A) JP 62-297024 (JP, A) JP 59-9298 (JP, B2) Fukui Masahiko, Kinoshita Natsuo, Development of Wire Electrodes in Wire EDM (1st Report), The Institute of Electrical Processing, Japan, Inc. Engineering Society, March 31, 1983, Volume 16, Issue 32, p. 25-36 (58) Fields investigated (Int.Cl. ⁷ , DB name) B23H 7/08 C22C 9/04

Claims (3)

(57) [Claims] 1. An electrode wire for wire electric discharge machining, comprising mainly brass with a Cu content of 60 to 65% by weight, said brass containing 0.01 to 0.09% by weight of Al , 20
Tensile strength at 0 ° C / tensile strength at 25 ° C) x 1
The strength ratio calculated by 00 (%) is 60% or more and 90% or less.
An electrode wire for wire electric discharge machining, characterized by being full . 2. The tensile strength is 90 kg / mm ² or more, and the ratio of 0.2% proof stress to the tensile strength is 0.8.
The electrode wire for wire electric discharge machining according to claim 1 , wherein the electrode wire is 5 to 0.95. 3., wherein the wire diameter is 0.1mm or less, according to claim 1 or wire electrical discharge machining electrode wire according to 2.