JPS6012163B2 - Electrode for electrical discharge machining - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrode for electric discharge machining, and particularly to an electrode for electric discharge machining suitable for machining deep holes with high precision.

Electrodes that have been put to practical use as electric discharge machining electrodes are roughly divided into those containing W as a main component, those containing Cu as a main component, and those containing carbon as a main component. Materials containing W as a main component have the advantage of high processing accuracy and low electrode wear, but have the drawbacks of slow processing speed and relatively high cost.
In addition, materials mainly composed of inexpensive Cu or carbon are relatively fast in machining speed, but the electrode wear is extremely large, making them unsuitable for precise electrical discharge machining. The above-mentioned electric discharge machining electrodes are used to take advantage of their respective advantages, and efforts have also been made to improve their respective disadvantages. However, when drilling deep holes with high precision by electrical discharge machining, each of these drawbacks becomes particularly noticeable, and the lack of suitable electrode materials has been a major industrial hurdle.

For example, when attempting to make a high-precision deep hole in tool steel (SKDII-JIS) with a size of 2 by 4 and a depth of 5 to 10 by electrical discharge machining, W is the main component. If the main component is Cu or carbon, a long electrode must be used due to large wear and the machining accuracy is significantly inferior. However, in both cases it was unsatisfactory.
The present invention particularly provides an industrially useful electrode for electric discharge machining that can efficiently machine such high-precision deep holes. The electrode for electric discharge machining according to the present invention combines the advantages of a member mainly composed of W and a backing material mainly composed of Cu, so that it is suitable for deep hole machining. At one end, we arranged a member whose main component is Cu, which is relatively wear-intensive but has a high machining speed, and at the other end, a member whose main component is W, which has good processing accuracy.These are joined together to form a structure. It is characterized by what it did. According to the electrode for electrical discharge machining according to the present invention, rough machining is performed at the tip portion where the main component is Cu, and finishing machining is performed at the end portion where the main component is W. You can make use of it.

The material mainly composed of Cu constituting the electrode for electric discharge machining according to the present invention may have a Cu content of 50% or more, but it is preferable that the electrode wear rate is improved by Ti02 by weight.
MoZ no 2, Tho2~ Y203 “V203, V3Q
25% or less of at least one of these, the remainder being substantially C
It is preferable that the member be made of u.

Here, metal oxides such as TiO2 and ZN2 improve the degree of electrode wear, and this effect is significant within the above range. Furthermore, it is preferable that metal oxides such as Ti02 and Zr02 are powdered and contain 30% or more of particles with an average particle size of 1.4 or more and a particle size of 1.0 or more. This is excellent because it has less electrode wear.This excellent Bemura chopstick was created by the applicant Ayase Sho 49-7202.
It is disclosed in the issue. Furthermore, for the village whose main component is W, W is 5.
It may be 0% or more, but it is particularly preferable that the processing speed is improved, and the weight percentage is 15 to 40% of Ag and Cu alone or in combination, 0.5 to 10% of Zr02, and the balance is substantially It is preferable that the member is made of W.

ZrQ is particularly effective in improving processing speed and reducing electrode wear, and its effects are significant within the above range. Furthermore, Cu and Ag improve the electrical conductivity to thermal conductivity of W, and the above ranges are desirable. In this case, Zr02
In the powder state, the average particle size is 14 or more and the particle size is 1.

Those containing 30% or more of 0 or more are preferable.

This excellent member was specially designed by the applicant in 1977-126.
It is disclosed in No. 21.

EXAMPLE First, a material containing Cu as a main component, which constitutes the processed tip of an electrode, was obtained.

In other words, electrolytic copper powder divided by -325 mesh,
After weighing 90:10 (weight ratio) of 2 powders of Z containing 91% of particles with a particle size of 1.0 A or more and having an average particle size of 3 Buddha and a purity of 99.5%, and mixing in a pot for 3 hours using the sea method. Dry, 15
It was divided into stripes using 0 mesh to obtain a raw material powder.

This was pressure-formed in a press with an n of about 4, and then ``65 in a hydrogen furnace.
0, 0, 1 hour competition. This is further pressed 5.
The pressure was applied again to 5 tons, and vacuum binding was performed at 80,000 for 1 hour to obtain a section with a predetermined shape.

Next, a member containing W as a main component and forming the base of the electrode is obtained.

Added 5% Zr02 powder to W powder and further added 1325he
A small amount of heSh electrolytic steel powder was added and blended.This mixture was mixed in a stainless steel pot using an overflow method, and paraffin was added as a ticket tying agent in the form of an approximately 1% benzine solution. The sieve went Lena.

The raw material mixed powder thus obtained was placed in a mold at 1℃n.
Compression molding was carried out under a pressure of about 300 yen. Next, this compact was heat-treated in a Rentsugi sintering furnace at about 1,000 to 11,000 C for about 1 hour to clean the ring, and after sintering, it was placed in a molybdenum boat lined with an alumina plate, and an appropriate amount of After stacking electric steel, this is heated in a continuous hydrogen furnace (fog point -4000)
) was used to infiltrate copper by passing it through a temperature range above the melting point of copper for an appropriate time.As a result, Cu27%-
A Miyako village of a predetermined shape consisting of Zr02344% and the balance W was obtained.

The two types of parts thus obtained were joined together to obtain an electrode for electric discharge machining as shown in the figure.

The members were joined using silver solder (JIS-BAG3 equivalent). Note that the members may be joined by other means that do not impair the characteristics of the electric discharge machining electrode and have sufficient joint strength.

In the figure, 2 is a member whose main component is Cu, 2 is a member whose main component is W, and 3 is a shank for attachment to an electrical discharge machine.

The shank 3 is attached to the electrical discharge machining electrode by, for example, a screw connection. In this electric discharge machining electrode, the machining direction is the direction of arrow A.

Table 1 shows the results of deep hole electrical discharge machining using the electrode for electrical discharge machining constructed as described above, in comparison with the results obtained using the conventional electrode for electrical discharge machining.

Note that the electrical discharge machining conditions are shown in Table 2.

Table 1 Table 2 In Table 1, the processing depth indicates the thickness of the workpiece, and the electrode thickness indicates the thickness of the electrode necessary to process the workpiece to a predetermined thickness.

Therefore, this value can be considered to indicate the degree of electrode wear. Processing time indicates the time required to perform the specified processing,
The smaller the number, the higher the processing speed. As is clear from the table, the electrode of the present invention shows favorable results in a well-balanced manner in the degree of electrode wear indicated by electrode thickness, processing speed, and processing accuracy when compared with other electrodes.

Moreover, its price is in the middle of the conventional price, which makes it preferable. As described above, the electrode of the present invention can be said to be preferable when compared with conventional electrodes, and is particularly effective when machining deep holes with high precision. In the electrode of the present invention, the thickness of the part mainly composed of Cu and the thickness of the member mainly composed of W can be appropriately selected depending on the workpiece and processing conditions.

As described above, the electrode of the present invention has comprehensively improved characteristics required for an electrode for electric discharge machining, and has great industrial value.

[Brief explanation of drawings]

The figure shows one embodiment of the electrode for electric discharge machining according to the present invention. 1...Member whose main component is Cu, 2...Member whose main component is W, 3...Shank.

Claims (1)

[Scope of Claims] 1 The machining tip during electrical discharge machining is a member whose main component is Cu, and the other end is a member whose main component is W, and these members are integrally joined. Electrode for electrical discharge machining. 2 The member whose main component is Cu has TiO_2 in weight%,
ZrO_2, ThO_2, Y_2O_3, V_2O_3
, V_3O_5 in an amount of 25% or less, and the remainder being substantially Cu.
Electrode for electrical discharge machining as described in section. 3 The member whose main component is W contains 15 to 4% of Ag and Cu alone or in combination by weight.
0%, ZrO_2 0.5-10%, the balance is substantially W
The electrode for electric discharge machining according to claim 1 or 2, which is a member consisting of. 4 The metal oxide added to the member mainly composed of Cu and the member mainly composed of W has an average particle size of 1 in powder form.
．． The electrode for electric discharge machining according to any one of claims 1 to 3, which contains 30% or more of particles having a particle size of 4μ or more and a particle size of 1.0 or more.