JPS6045262B2 - Copper alloy suitable for electrode material for electrical discharge machining - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a copper alloy suitable for manufacturing an electrode for electric discharge machining, and in particular, to an electrode material for electric discharge machining which the present inventors previously disclosed in Japanese Patent Publication No. 22116. Regarding the improvement of alloys.

The alloy disclosed in the above-mentioned Japanese Patent Publication No. 38-22116 is composed of 1 to 5% cuprous oxide Cu, O, and the balance is copper Cu and as little impurity as possible (O, 0.05% or less).
u.

O-Cu eutectic (including hypoeutectic and hypereutectic; the same applies hereinafter)
It is an alloy that has excellent mechanical machinability, and is far superior to brass and pure copper in terms of machining performance such as machining speed, electrode wear, and machining stability, and can be provided at a price comparable to that of brass and pure copper. It was hot. In addition, the present applicant previously proposed a Cu-Zn-Zr ternary alloy suitable for an electrode material for electrical discharge machining in Japanese Patent Application No. 134064/1983.

This alloy also has excellent free machinability and ductility, as well as excellent electrode wear ratio, machining speed, and machining stability. Therefore, the present inventors discovered that the above-mentioned Cu.

The combined addition of Zn and Zr to the 0-O alloy further improves the free machining properties and mechanical strength, and also improves the machining speed, machined surface roughness, and machining stability in electrical discharge machining. We have discovered that the electrode wear ratio can be reduced without loss, and that by appropriately changing the processing conditions, it is also possible to improve processing characteristics other than the electrode wear ratio.
The invention has been completed.

Therefore, the gist of the present invention is that the a phase (0 to pure copper)
．． Zn and Zr are added in a total amount of 0.01 to 5% to a base alloy containing 0.05 to 1% oxygen in the form of CO dispersed in a solid solution containing 0.4% oxygen dissolved therein. Therefore, the alloy of the present invention contains cu2o.
-2n-2 is a -c Syuyuan alloy. When producing the alloy of the present invention, a predetermined amount of pure copper is melted in a crucible in advance in an inert air flow using an induction heating furnace, and then cu2oN2n and Zr is added and dissolved, poured into a desired mold, and cooled. Then, Z
Cu without addition of n and Zr.

In O-Cu based alloys, Cu. When the amount of O added is 1% or less (oxygen amount 0.11% or less), there is no noticeable difference compared to a pure copper electrode, and when the amount of O added is 5% or more (oxygen amount 0.45% or more), In this case, even if it is possible to cast to some extent, it becomes extremely brittle like a kind of semi-sintered body and cannot be used as an electrode material. Depending on the amount, CU2O
Addition amount is 0.45% (oxygen amount 0.05%) or more, 9%
(1%) Well, it will be useful. That is, the addition of Zn and Zr improves machinability and electrode wear ratio in the low compounding ratio region of 0.45 to 1% CU2O addition, and improves malleability and casting ratio in the high compounding ratio region of 5 to 9%. Since the properties of each type are improved, it can be used in any area. Therefore, in the alloy of the present invention, the blending ratio of CU2O is 0.
．． It is set at 45% or more and 9% or less. Therefore, a more preferable CU2O blending ratio is 0.45 to 3%, more preferably 0.6 to 1% for the consumable area, although it depends on other conditions.
%, and for non-consumable areas it is less than 3%, and even 0.
．． 45% to 0.7%.

Next, the blending ratio of Zn and Zr will be described. Generally, the purpose of adding Zn is to improve free machinability and alleviate brittleness, and the purpose of adding Zr is to improve electrical discharge machining characteristics such as electrode wear ratio. Of course, it is necessary to add them in combination. Therefore, both Zn and Zr are 3%
Since the above high proportions impair the stability of electrical discharge machining and increase the electrode wear rate, it is impossible to contain more than 3% of either one or 5% or more in total.

Moreover, since Zn is effective even when added in a small amount of about 0.01%, the lower limit of the addition amount is 0.01%.
01%.

Although these more desirable blending ratios depend on the oxygen content and the intended use of the electrode, Zn. ．． Both Zr contents are 0.2 to 1.5%, respectively, and the total amount is 1 to 2% or a value around that.

Examples will be described below.

[Example 1] 0.3% Zn and 1% Zr were added to electrolytic copper to cast a base alloy ingot, and CU2O was added to this in various blending ratios to form three alloys with different oxygen contents. A large number of rods were cast and turned on a lathe to produce round rod electrodes, and SKD-5 was test-processed using these rods.

The processing conditions are the following two types i) and Ii).

i Non-consumable machining (rough machining) 3 Machining fluid: Kerosene Peak current 1p: 21A Discharge pulse τ0n: 600μSec Machining speed: 600rr1g/Min ll Consumable machining (finishing) 4. Machining fluid: Kerosene Peak current 1p: 150A Discharge pulse τ0n : 5μSec Processing speed: 90rr 1g/Min The oxygen content and electrode consumption ratio of these electrode materials were as shown in the following table.

From the above table, it is clear that when the electrode material of the present invention is used, electrode consumption is significantly reduced.

In addition, especially the above-mentioned brown. 3 and NO. It turns out that 4 electrodes give particularly good results. Also, No. l or no. It was found that cutting of the electrode No. 5 was extremely easy, and electric discharge machining using these electrodes was also performed in a stable state.
[Example ■] 3.4%C where a complete eutectic of α phase and CU2O is formed
1.2% Zn and 0.6% Zr are blended into a U2O-CU base alloy, melted and cast into a mold to obtain a round bar, which is then turned to produce a round bar electrode. -5 was subjected to electrical discharge machining.

The processing conditions are as follows.

Machining fluid: Kerosene Peak current 1p: 4.1A Discharge pulse τ0n: 200μSec Machining depth: 35T111n Under these conditions, electrode wear was about 0.01% on average.

Furthermore, for finishing processing, IP=5ω\τ0n=15μ
When processed as Sec, with an electrode consumption ratio of 8%, 8
A good surface finish of pRmax was obtained.

Since the present invention is constructed as described above, the present invention has superior machining properties such as mechanical machinability and electrode consumption ratio, and is advantageous in terms of price, compared to known CU2O-CU alloys. D can provide an electrode material for electrical discharge machining. In addition, in the above embodiment, the electrode material of the present invention was processed using Kametsune's kerosene as the working fluid, but the alloy of the present invention can also be wire-drawn, and the wire drawing process using water as the working fluid is also possible. (It can also be used as a cutting electrode.)

Claims (1)

[Claims] 1 Pure copper with 0.45 to 9% Cu_2 by weight percentage
A copper alloy suitable for an electrode material for electric discharge machining, which is made of O and 0.01 to 5% of Zn and Zr in total.