JPS59222547A - 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 reducing sticking to a body to be machined by adding a small amount of Si to a Cu-Zn alloy having a specified composition. CONSTITUTION:This electrode wire for wire electric spark machining has a composition consisting of 20-40wt% Zn, 0.1-5wt% Si and the balance Cu. The wire is obtd. by adding Zn and Si to Cu so as to increase the electric spark machining speed while maintaining the satisfactory wire drawability. A Cu-Zn- Si alloy ingot having said composition is hot worked, and it is repeatedly subjected to wire drawing and annealing to obtain the desired electrode wire for wire electric spark machining. This electrode wire produces a remarkable effect on electric spark machining.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrode wire for wire electric discharge machining, and particularly to an electrode wire that improves the speed of electric discharge machining and has a small amount of adhesion to a workpiece.

Wire electrical discharge machining is an electrical discharge phenomenon that occurs between the electrode wire for wire electrical discharge machining and the workpiece, and the heat generated by the electrical discharge causes
This machine melts and cuts the workpiece and is particularly suitable for continuous processing of workpieces such as molds for press machines that have complex and precise shapes. In wire electric discharge machining, the finished surface condition and dimensional accuracy of the workpiece are required to be good, the electrode wire does not stick to the workpiece, and the electric discharge machining time is short. In order to satisfy the 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 type of wire electric discharge machine and workpiece are specified, the finished surface condition, dimensional accuracy, and electric discharge 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 also important characteristics, but when considering the cost and running costs of the wire electrical discharge machine, the electrical discharge machining speed (amount of workpiece per unit time) and electrode wire splash are important characteristics. Emphasis is placed on the amount of adhesion to the workpiece.

Conventionally, this electrode wire has been made of hard copper wire or 6515 wire depending on the purpose.
5 brass wire, tungsten wire, etc. are used, but when these are used, the electrical discharge machining speed is inferior, and in particular, hard copper wire and 65/35 brass wire have the disadvantage of a large amount of adhesion to the workpiece. , its improvement is strongly desired.

In view of this, and as a result of various research studies, the present invention has developed an electrode wire that has excellent electrical discharge machining speed and less adhesion to the workpiece.
This electrode wire for wire electrical discharge machining is characterized by containing 1 to 5 vit % of Cu, with the remainder being Cu.

That is, in the present invention, by adding Zn and Si to Cu, when used as an electrode wire, the electrical discharge machining speed is significantly improved, and the adhesion to the workpiece is significantly reduced.
The present invention was based on the discovery that it can be easily manufactured.

Next, the reason for limiting the amount of each element added in the present invention will be described.

It is Zn that makes Znff1 20-110 wit%
If the amount is less than 20 wt%, the improvement in electrical discharge machining speed will be small;
) When it exceeds 10 wt %, the β phase increases rapidly, making wire drawing difficult. The desirable range of the amount of Zn added is 50 to 57%.

If the Sl content is less than 0.1 wt%, the wire drawability is good, but the contribution to the electrical discharge machining speed is small, and if it exceeds 5 wt%, wire forming and cold wire drawing become difficult. a·? Ru. The heavy S1 addition amount is between 05 and 25.

It should be noted that the electrode wire of the present invention contains unavoidable impurities to the extent that are normally contained in the Qu raw material.The present invention will now be described with reference to Examples.

Cu was melted in a graphite crucible using a small high-frequency melting furnace, and 81 was added as a master alloy with the surface of the melt coated with charcoal, and after the temperature of the hot water had subsided, Zn was added.
Ingot with the composition shown in the table (width 25 mm, thickness 25 mm, length 3
50 shares).

Next, the ingot was raised 2 mm per side and then 850 mm
A wire with a diameter of g mm was produced by heating the wire to 0.degree. C. and hot working, and then wire drawing and annealing were repeated to produce an electrode wire with a diameter of 02.

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

In addition, for comparison, conventional electrode wires were similarly investigated and are also listed in Table 1.

The electric discharge machining speed was determined from the ratio of the amount of workpiece (mg) to the machining time (minutes), and was expressed as a relative value when the electric discharge machining speed when using hard copper wire was set to 100. Therefore, the larger this value is, the higher the electrical discharge machining speed is.

However, the amount of adhesion to the workpiece is determined by surface analysis using a chi-ray analyzer, and it is found that the amount of adhesion when processing with hard copper wire is ZIZ <
The amount of adhesion to A; is taken as 100, and compared with this. Therefore, the smaller the value, the less the adhesion h1- to the workpiece.

Difficulty in manufacturing was determined by observing buildability and wire drawability, and grading good ones as easy and bad ones as difficult.

Note to Table 1: A mark in the table indicates that the electrode wire could not be manufactured.

As is clear from Table 1, the electrode wires Nα1 to j5 of the present invention have greatly improved electrical discharge machining speed compared to the conventional electrode wires Nα20 and Nα21, and the amount of adhesion to the workpiece is also reduced. You can see that

On the other hand, the comparative electrode wire N[116, which contains less Zn and Si than the electrode wire of the present invention, is easy to manufacture, but the increase in the electrical discharge machining speed is small and there is no significant effect on reducing the amount of deposited material.
The electrical discharge machining speed of the comparison electrode wire Nα117 with a large amount of Zn (with a small amount of Si), the reference electrode wire Nα18 with a small amount of Zn (with a large amount of Si, and the reference electrode wire Nα19 with a large amount of Zn and Sl) is improved, but the speed has almost reached a saturated state. Moreover, the number of times of annealing in the middle is increased, and wire breakage is likely to occur, making manufacturing difficult and increasing costs, which is not industrially advisable.

As described in detail above, the wire electric discharge machining electrode wire of the present invention is an excellent electrode wire that has an excellent effect of increasing the speed of electric discharge machining, and is an excellent electrode wire that causes less damage to the workpiece, and has a remarkable effect on electric discharge machining. be.

Claims (1)

[Claims] Zn 20-IIOwt%, Si 0.1-5w
An electrode wire for wire electrical discharge machining, characterized in that it contains t% and the remainder is Cu.