JPS59170230A - Electrode wire for wire electric spark machining - Google Patents

Abstract

PURPOSE:To obtain an electrode wire for wire electric spark machining having a high electric spark machining speed and causing hardly any sticking to an article to be machined by adding a specified amount of Mg combined optionally with Al to Cu and by working the resulting alloy into a fine wire. CONSTITUTION:To Cu is added 0.2-1.5wt% Mg combined optionally with 0.5- 2.0wt% Al, they are alloyed, and the alloy is worked into a fine wire of about 0.2mm. diameter to manufacture an electrode wire for wire electric spark machining. When an article is subjected to electric spark machining such as melt cutting using the electrode wire, the machining speed is increased, and the Cu alloy of the electrode wire does not stick to the article. Accordingly, electric spark machining giving a fine finished surface state and superior dimensional accuracy can be carried out at a high working speed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrode wire for wire electrical discharge machining, and particularly to an electrode wire for improving electrical discharge machining speed and reducing sticking to a workpiece.

Wire electric discharge machining is a process in which a running wire with a diameter of approximately 0.2 mm is used as an electrode wire to cause an electrical discharge phenomenon between the workpiece and the workpiece, and the workpiece is melted and cut by the electric discharge. It is suitable for processing workpieces made of cemented carbide such as molds for press machines having a shape.

In such wire electrical discharge machining, there are particularly strong demands that the finished surface condition and dimensional accuracy of the workpiece be good, that droplets scattered from the electrode wires will not adhere to the workpiece, and that the electrical discharge machining time be short. Therefore, in order to satisfy these electrical discharge machining characteristics, it is necessary to improve the efficiency of the electrical discharge phenomenon that occurs between the electrode wire and the workpiece.

Generally, in wire electric discharge machining, once the model of the wire electric discharge machine and the workpiece are specified, the finished surface condition, dimensional accuracy, and machining speed of the workpiece are largely influenced by the electrode wire used.

In wire electrical discharge machining, the finished surface condition and dimensional accuracy of the workpiece are important characteristics, but considering the cost and running cost of the wire electrical discharge machine, the electrical discharge machining speed (amount of workpiece per unit time) and the accuracy of the workpiece It is important that the amount of adhesion is small.

Conventionally, hard copper wire, 65735 brass wire, tungsten wire, etc. have been used as electrode wires for electrical discharge machining, depending on the purpose, but the speed of electrical discharge machining is low for all of them, and hard copper wire and 65/35 brass wire are still difficult to use. There is a drawback that there is a large amount of adhesion to the workpiece, and there is strong hope that this can be improved.

In view of this, as a result of various studies, the present invention has developed an electrode wire that improves the electrical discharge machining speed to 1 J and has a small amount of adhesion to the workpiece. ~
The second invention contains 1.5 wt% of Mg and the remainder is Cu and unavoidable impurities.
This is an electrode wire for wire electrical discharge machining, characterized in that it contains ~2.0 Wt%, with the remainder consisting of Cu and unavoidable impurities.

That is, in the present invention, the addition of CuKMg improves the discharge characteristics and heat resistance of the electrode wire, and when CuKMg is used as the electrode wire, the tension of the electrode wire can be increased during electrical discharge machining.
The first invention was obtained by discovering that the electrical discharge machining speed was improved to an average of 1 [1] and there was little adhesion to the workpiece, and when AQ was added to the composition of the first invention, the electrical discharge machining speed was improved. It was discovered that this was further improved and the second invention was created.

However, the reason why the range of each additive element is limited as described above in the present invention is as follows.

Mg is 0.2-1.5 wt%.
If it is less than 1.5 wt%, the effect of increasing the electrical discharge machining speed and reducing the amount of adhesion will be small, and if it exceeds 1.5 wt%, the casting property,
This is because wire drawability is significantly reduced.

AA gave Affi 05~2.0w to Q, 5
Below the wt ratio, the effect of improving the electrical discharge machining speed is not significant (
This is because if it exceeds 2.0 wt%, the effect of improving the electrical discharge machining speed will be saturated, and the castability will decrease, the wire drawability will be poor, and multiple intermediate annealing will be required, resulting in high costs. .

Incidentally, in the present invention, there is no problem even if it contains unavoidable impurities to the extent that they are contained in the Cu base metal normally used.

The present invention will be explained below with reference to Examples.

Cu was melted in a graphite crucible using a small high-frequency furnace, Mg and AA were added while the melt surface was covered with charcoal, and an ingot (', dE 2' 5 mm, thickness The length was 253 mm and the length was 1 I00 mm).

Next, this ingot was subjected to 2-face control per side, heated to 850°C, and hot-worked with grooved rolls to give a straight q% of 8.
A roughly drawn wire with a diameter of 0.2 mm was produced by repeatedly drawing and annealing the wire.

The electrode wire thus obtained was attached to a wire electrical discharge machine, and the electrical discharge machining speed and the state of adhesion to the workpiece were examined, and the results are shown in Table 1.

The electric discharge machining speed of each electrode wire is determined by comparing the value obtained from the ratio of the amount of workpiece (mg) to the machining time (minutes) with the electric discharge machining speed of the hard copper wire, and taking that of the hard copper wire as ioo. Shown as relative values. Therefore, the larger this value is, the higher the electrical discharge machining speed is.

However, the amount of adhesion of each electrode wire to the workpiece is determined by surface analysis using an X-ray analyzer, and the amount of adhesion on the workpiece processed with the hard copper electrode wire is set as 100, and the relative amount is compared with this. Shown as a value. Therefore, the smaller the value, the smaller the amount of adhesion to the workpiece.

In addition, the difficulty of manufacturing was determined by taking into account the castability, the number of annealing required during wire drawing, and the state of breakage, and the results are also listed in Table 1.

Table 1 Note: A mark in the electrical discharge machining speed and amount of adhesion to workpiece column indicates that the electrode wire could not be manufactured due to poor castability and wire drawability.

As is clear from Table 1, the electrode wire N [11 to 115
i7j, it can be seen that the electrical discharge machining speed is greatly improved r1j compared to the conventional stop line Nα20.21, and there is less adhesion to the workpiece.

On the other hand, the Mg
The comparison electrode wire N[1111 with a small value of Nα is easy to manufacture.
Comparative electrode wire Na 18 is easy to manufacture but has a small effect on improving the electrical discharge machining speed, and has a large amount of Mg (comparative electrode wire Na 18 has a large amount of evening wire Nα17 and Al!).
It can be seen that the electrode wire could not be manufactured at 1 ton, probably due to manufacturing difficulties.

As mentioned above, the electrode wire of the present invention has a high electrical discharge machining speed and less adheres to the workpiece, and is suitable for wire electrical discharge machining.
It has an amazing effect.

Claims (2)

[Claims] (1) An electrode wire for wire electrical discharge machining, characterized in that it contains 0.2 to 1.5 wt of Mg, and the remainder consists of Cu and unavoidable impurities. (2) MgO, 2-1.5wt% and further AlO
, 5-2.0 wt%, with the remainder consisting of Cu and unavoidable impurities.