JPS59205441A - Electrode material for wire cut discharge processing - Google Patents

Abstract

PURPOSE:To provide the titled electrode material increased in a processing speed, reduced in an arc-proof amount and prevented from short circuit, obtained by preparing an alloy from Cu, Al, a rare earth element and Zn in a specific ratio. CONSTITUTION:An alloy consisting of, on a wt. basis, 60-80% Cu, 0.1-2% Al, 0.05-1% rare earth element and the remainder of Zn and inevitable impurities is prepared. In this case, as the rare earth element, one or more of an element selected from a group consisting of Y, Sm, La, Ce and a misch metal is used. By this method, an electrode material excellent in conductivity, heat resistance and tensile strength is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a metal material suitable as a wire electrode material for a wire-cut electrical discharge machining device.

Wire-cut electrical discharge machining equipment causes an electrical discharge phenomenon between a wire electrode and a workpiece, and cuts the workpiece using the heat and shock generated by the discharge. It is especially suitable for machining such workpieces.

In general, wire-cut electrical discharge machining is required to have a good surface finish and dimensional accuracy of the workpiece, and to shorten the machining time.In order to satisfy these requirements, wire electrode It is necessary to improve the machining efficiency due to the electric discharge that occurs between the machine and the workpiece. On the other hand, the power supply type of the electrical discharge machining equipment, the material of the workpiece, the surface finish condition,
Once dimensional accuracy and the like are specified, the electrical discharge machining time and the like will depend on the material and wire diameter of the wire electrode used.

Therefore, as a wire electrode material, it should be easy to draw, have good conductivity, have a high processing speed when used as an electrode, and preferably have a low consumption ratio.
It has good heat resistance, does not deteriorate in tensile strength especially at high temperatures, and is difficult to cut during use, and is resistant to work hardening and short circuits.
In addition, it is possible to perform two-dimensional machining, three-dimensional machining, and even machining at locations where the wire electrode is wound or bent. Properties such as small μ) and good hydrophilicity are required.

For this reason, pure copper or a copper alloy such as brass is generally used as the electrode material, and copper alloys to which cuprous oxide is added have also been proposed.

Copper electrodes have good electrical conductivity, but their wear ratio is around 60%, and they are insufficient in terms of mechanical strength such as tensile strength and heat resistance, and brass wire has poor mechanical strength such as tensile strength. Although it is superior to copper wire in terms of physical strength and processing speed, it is somewhat inferior in terms of conductivity and wear rate. Brass wire has higher tensile strength and hardness than hard copper, that is,
Because it has spring properties, there is a residual curl, and unless the guides are moved with a sufficiently large tension, it is difficult to achieve sufficient straightness, and the problem of machining accuracy and wire breakage is contradictory. Was.

On the other hand, an alloy wire made of pure copper mixed with 1-5% cuprous oxide Cu2O has the same electrical conductivity as pure copper, and the wear rate is 20-30%.
Although the processing speed is excellent, there is still a problem with difficulty in cutting.

On the other hand, tungsten, molybdenum or their alloys are about 0.
There are wire electrodes drawn to a diameter of around 1 mm or less, but they are expensive and have only been used for special purposes.

In addition, wire-cut electric discharge machining equipment generally moves a wire electrode from one reel to the other, and processes a desired shape by performing electric discharge machining by supplying machining fluid and performing pulse discharge. Therefore, the wire electrode is twisted and bent each time it passes between the brake roller and the pinch roller, between the capstan and the pinch roller, between the guide roller and the guide guide, etc., and this causes the wire electrode to undergo work hardening. This may result in loss of linearity, or conversely, if processing is attempted at a strongly bent portion of the wire electrode, it may be impossible to obtain a small bending radius, resulting in overhang of the workpiece. There is a problem in that it is not possible to process the contours of parts, such as the hollow part of an extrusion die, the cutting edge part of an L-rim die, etc.

The present invention was made from the viewpoint of ridges, and its objectives are to have good electrical conductivity and heat resistance, high tensile strength, breakability, and very high processing speed. In addition, the present invention provides an electrode material for wire-cut electrical discharge machining that can be easily drawn, has a small amount of tension, can prevent short circuits, and has low contact resistance, low surface resistance, and low barrier resistance. It's about doing.

Therefore, the gist is that Cu of 60 to 80% by weight (the same applies hereinafter), 81 of 0.1 to 2%,
It is present in an alloy consisting of 0.05 to 1% of at least one rare earth element selected from Y, Sm, La, Ce, miso metal, etc., and the balance being Zn and unavoidable impurities.

In particular, as mentioned above, f for wire force/throat electric discharge machining
All materials containing rare earth elements are known.

For example, JP-A-53-49397 discloses an electrode system in which Cu or Cu+Cu2O alloy contains one or more rare earth elements in an amount of 0.1 to 5% by weight. -90943 publication contains 1 to 40% Z
An alloy for wire force/nod electric discharge machining electrodes is described, which contains one or more of n, Mn, Mg, and rare earth elements) in a total of 0.1 to 3%, and the balance is Cu. It is like that.

However, the addition of rare earth elements in electrode materials made of Cu-based alloys such as Cu and various brass such as Cu-Zn improves the tensile strength and breakability, as well as improves the performance of electric discharge machining, especially , is effective in increasing the machining speed, which is thought to be a result of the contribution of rare earth elements to the generation of electric discharge, etc., but the amount of deflection of the wire electrode (so-called tyro amount μ) during electric discharge machining
) is large, and there is a problem in that short circuits cannot be prevented even with a short circuit.

In addition, the main component is 81, and the weight percentage is 0.5 to 1.
Add 0% Ni and 0.05-0.5% Pd, or
Or, based on AI, the weight percentage is 0.5~
The one containing 10% Ni, 0.05-0.5% Pd, and further 0.01-0.5% of a rare earth element such as Mitshu metal or Y2O3 is disclosed in JP-A-53-49 mentioned above.
Compared to the alloy for wire-cut electric discharge machining W poles described in No. 397 or JP-A No. 56-90943, its tensile strength and breakability are improved, and the performance and machining speed of electric discharge machining are increased. Although it was possible to reduce the so-called typhoon amount and further prevent short circuits,
However, the effect was still not satisfactory for the city.

According to various test studies conducted by the present inventor, the weight percentage is 6.
0-80% Cu, 0.1-2%^1, and 0.05
The above problem can be solved by making an alloy consisting of ~1% of YSSm, La, Ce, and one or more rare earth elements selected from La, Ce, Misos metal, etc., and the balance being Zn and unavoidable impurities. did it.

That is, the advantages of wire-cut electrical discharge machining electrode materials containing so-called rare earth elements, which can improve tensile strength and breakage, and increase electrical discharge machining performance and machining speed, can be greatly improved. It becomes possible to solve the problems that the so-called typhoid amount increases and short circuits cannot be prevented, which have been disadvantageous.

In particular, 62% Cu, 0.6% A1, and 0.16%
It is recommended to use an alloy consisting of Misoshu metal with the balance being Zn.

When electric discharge machining was performed using the above alloy, the machining speed was significantly increased compared to conventional electrode materials for wire-cut electric discharge machining, the amount of coil was reduced, and short circuits could be prevented.

Using the electrode material for wire cut electric discharge machining according to the present invention, machining was performed under the following machining conditions.

Examples will be shown below in comparison with processing examples using conventionally known electrode materials.

<Machining conditions> No-load voltage 130V τON6~15μS τOF [7μs 1M (average machining current) 7.5A machining fluid Specific resistance 30. X103ΩG pure water machining fluid upper nozzle discharge pressure 0.6 kg/min machining fluid lower nozzle discharge pressure
1 kg/min wire electrode feeding speed 1.
5m/min wire electrode diameter 0.2 mφ
Thickness and material of workpiece 25m+, 355C material [Example] Alloy composition of wire electrode (Cu-■-Misoshmetal-Zn alloy>Cu
62% to 8I
O, 6% Misos Metal 0.16% Zn
When electrical discharge machining was performed using a wire electrode made of the electrode material for wire-cut electrical discharge machining according to the present invention, machining could be performed at a machining speed of about 64 m2/min.

Also, the roughness of the machined surface at that time was 13μRmax).

On the other hand, the alloy composition of the wire electrode (zn-Cu alloy) Zn 33%Cu
The above-mentioned average machining current IM is approximately 7.67% using the conventionally known electrode material for wire-cut electrical discharge machining. When electric discharge machining was performed under OA machining conditions, the machining speed was approximately 52 2/min.

Further, the roughness of the machined surface at that time was 11 μRmax.

Further, electric discharge machining was performed using another conventionally known wire-cut electric discharge machining electrode material under the same conditions as above.

Alloy composition of wire electrode (Cu-Zn-Mg-Mn-T i -A I alloy) Cu 4% Zn
20% Mg
1.5%MnO, 5%T
i to 0.5%8
73.5% This result was almost the same as the result for the above (Zn-Cu alloy).

Since the present invention is structured like a ridge, the electrode material for wire-cut electric discharge machining according to the present invention can be easily wire-drawn, and has good electrical conductivity and heat resistance. Since the tensile strength is high, the wire electrode is hard to get bent, has a low consumption ratio, and almost never breaks during use, and it is possible to keep contact resistance, surface resistance, and barrier resistance low. Since short circuits can be prevented and processing can be performed at high current density, processing speed can be greatly increased and work efficiency can be dramatically improved.

Patent applicant: Agent of Inoue Japax Institute Co., Ltd. (
7524) Mogami Seitabu

Claims (1)

[Claims] 1) 60 to 80% Cu by weight percentage (the same applies hereinafter);
An electrode material for wire-cut electrical discharge machining, characterized in that it consists of 0.1-2% A1, 0.05-1% rare earth element, and the balance Zn and unavoidable impurities. 2) The electrode material for wire cap electrical discharge machining according to claim 1, wherein the rare earth element is Y. 3) The electrode material for wire-cut electrical discharge machining according to claim 1, wherein the rare earth element is 5Lll. 1) The electrode material for wire-cut electrical discharge machining according to claim 1, wherein the rare earth element is La. 5) The electrode material for wire cut electric discharge machining according to claim 1, wherein the rare earth element is Ce. 6) The electrode material for wire-cut electric discharge machining according to claim 1, wherein the rare earth element is Mitsushi metal.