JPH09234631A - Manufacture of electrical discharge machining electrode wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the heat resistance of electrode wire by using a Cu-Zr alloy wire as a core material, plating this core material subjected to Zn solution, quickly cooling the plated core material so as to form solid solution in Zr and Cu and then subjecting the same to cold extension while suppressing wire breaking and the roughness of the machined surface. SOLUTION: For manufacture of an electrical discharge machining electrode wire, first a Cu-Zr alloy wire is sent out while being positioned from a bobbin 10 by a positioning roller 12 and then sent into a coating furnace 5 after being passed through a nipple 3. In the coating furnace 5, the wire is plated by putting the same into the hot solution 2 of Zn or Cu-Zn supplied from a solution furnace 1, this plated Cu-Zr alloy wire is formed to have a specified diameter by a die 4 and then sent out of the coating furnace 5. Then, the alloy wire is sent to a cooling water tank 6 while being supported by a roll 7, quickly cooled and then taken up by a fixed speed take-up machine 9 and then the Cu-Zr alloy wire is subjected to cold extension by a wire extending machine 13 and taken up by a take-up bobbin 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an electrode wire for electric discharge machining, and more particularly to a method for manufacturing an electrode wire having Zr dissolved in Cu as a solid solution to improve heat resistance, that is, high temperature strength.

[0002]

2. Description of the Related Art As a conventional electric discharge machining electrode wire, for example, there is one shown below. (B) A wire material is composed of Cu-35% Zn brass wire to improve the processing speed (Journal of Copper and Brass Research, 26, 1).
987). (B) A wire rod having a metal coating made of an alloy containing at least 50% of Zn or the like on a metal core material (JP-A-57-564).
8). (C) A wire having a Cu—Zn phase layer formed on the surface of a Cu—Zn alloy core material (JP-A-61-197126). (D) A wire (Japanese Patent Publication No. 4-35543) in which the concentration of a metal element having a low melting point such as Zn is increased toward the outer surface. (E) A composite wire rod in which a steel wire is coated with a metal such as copper that has good electrical conductivity (Japanese Patent Publication No. 57-21721). (F) A wire rod comprising a copper-coated steel wire and a Cu-Zn alloy layer having a concentration gradient in which the Zn concentration increases toward the surface layer (Japanese Patent Publication No. 2-49849). (G) A wire rod having a Zn-rich layer formed on the surface by immersion annealing of Zn or a Zn alloy in a Cu alloy (Japanese Patent Laid-Open No. 62-21
8026). (H) A wire rod in which a Cu-Zn alloy layer having a specific thickness is provided on the outer peripheral surface of the Cu alloy wire, and a Zn layer having a specific thickness is provided outside the Cu-Zn alloy layer (JP-A-61-117021). ). (I) Cu, Cr, Zr, Fe, B with excellent thermal conductivity
A wire rod in which a Zn layer or a Cu-Zn alloy layer is formed on the outer periphery of an alloy wire containing 0.03 wt% to 5.0 wt% of one or more elements selected from e, Co, and Ti. 59-134624). (G) A wire produced by passing a Cu alloy through a molten bath of Zn or the like and cooling it while preventing oxidation (JP-A-59-12375).
2).

Among them, the electric discharge machining electrode wire disclosed in Japanese Patent Laid-Open No. 59-134624 is a Zn layer on the outer periphery,
Alternatively, it has a Cu—Zn alloy layer containing a higher concentration of Zn than the core material, and this coating layer improves the workability. On the other hand, tensile strength is required during electric discharge machining. In order to increase this, Cu-35% Zn brass wire is added with Cr, Mg, Zr, Ti, Si, Mn, and Al.
Etc. are also being considered. Also, in general, Cu
The Cu-Zr wire rod obtained by adding Zr to
Heat resistance is imparted by being subjected to a solution heat treatment performed by heating for 3 hours and subsequent water cooling.

[0004]

Therefore, in the conventional method of manufacturing the electrode wire for electric discharge machining, if the solution treatment of the Cu--Zr alloy is carried out at 950 ° C. for 3 hours, the cost is increased. Inevitably, the cost performance was poor, and there was a demand for streamlining the solution treatment.

Therefore, an object of the present invention is to provide a method of manufacturing an electrode wire for electric discharge machining which is excellent in cost performance in consideration of improvement in heat resistance.

[0006]

In order to achieve the above object, the present invention uses a Cu-Zr alloy as a core material, and the core material is plated through a Zn or Cu-Zn alloy molten bath. Provided is a method for producing an electrode wire for electric discharge machining, which comprises rapidly cooling a plated core material to give Zr a solid solution in Cu to provide heat resistance, and then performing cold wire drawing.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an apparatus for manufacturing an electrode wire for electric discharge machining embodying the present invention. This manufacturing apparatus includes a delivery bobbin 10 for delivering a Cu-Zr alloy wire, a positioning roll 12 for positioning the delivered Cu-Zr alloy wire, and Cu or Cu-Z on the Cu-Zr alloy wire.
coating furnace 5 for plating n and plated Cu-Zr
Rolls 7 and 8 for supporting the system alloy wire, a cooling water tank 6 provided between the rolls 7 and 8, and a constant speed for winding the plated Cu—Zr system alloy wire coming out of the cooling water tank 6 at a constant speed. Winding machine 9 and Cu-Zr after plating which was wound at a constant speed
A wire drawing machine 13 for cold drawing a system alloy wire, and a winding bobbin 1 for winding a cold drawn Cu-Zr system alloy wire after plating
One.

The coating furnace 5 is connected to a melting furnace 1 that melts Zn or Cu-Zn by being heated by a heater 1a, and receives a melt 2 of Zn or Cu-Zn from the melting furnace 1. The coating furnace 5 has a nipple 3 at the inlet and a die 4 at the outlet.

The operation will be described below. First, Cu-Z
The r-based alloy wire is fed from the bobbin 10 to the positioning roll
Zn is supplied from the melting furnace 1 after being positioned in 2 and fed into the coating furnace 5 through the nipple 3.
Alternatively, it is passed through the Cu—Zn melt 2 and a Zn or Cu—Zn coating layer is formed on the outer periphery of the Cu—Zr alloy wire. The Zn or Cu-Zn coating layer is a die 4
To a predetermined outer diameter and sent out of the coating furnace 5. Next, the plated Cu-Zr alloy wire is supported by the roll 7 and enters the cooling water tank 6, and after being rapidly cooled, it is taken up by the constant speed winder 9 while being supported by the roll 8. After this,
The plated Cu-Zr alloy wire is cold-drawn by a wire drawing machine 13, and the winding bobbin 11 is a wire material having a plating layer of a predetermined thickness on the outer periphery of the Cu-Zr alloy wire of a predetermined outer diameter. To be wound up.

FIG. 2 shows a waveform of a machining current when a workpiece is electric discharge machined using the electrode wire manufactured according to the present invention.
This waveform is a rectangular wave in which the maximum value I _p is 36 A, the ON time t ₁ is variable, and the OFF time t ₂ is 2.8 μs.

[0011]

Example 1 An example in which the electric discharge machining electrode wire manufactured by the present invention was used for machining is shown. Cu-0.16% Zr (outside diameter 2.6 mm) was used as a core material, and this was coated with Cu-40% Zn alloy to a thickness of 0.3 mm and solution-treated, and cold-drawn. An electrode wire for electric discharge machining having an outer diameter of 0.2 mm was produced. This coating layer is about 20 μm.

Using this electrode wire, SKD-11 (thickness: 40 mm) was processed by the pulse current shown in FIG. The result is shown in FIG. The electrode wire manufactured according to the present invention has a processing speed of about 1.5 as compared with the Cu-35% Zn wire.
Also, the ON time t _{1 of the} discharge pulse current (machining current) at which disconnection occurs is significantly extended. Actually, Cu-35%
Zn wire is applied for 1.2 μs for 1.95 mm / mi
While the electrode wire of the present invention was disconnected at the processing speed of n,
The disconnection did not occur until the application time of 1.5 μs and the processing speed of 2.35 mm / min.

The surface roughness of the work piece is 0.8 μs.
When the Cu-35% Zn wire was 1.315 μm, the electrode wire of the present invention was 1.285 μm at a voltage application time of 2.0 mm / min and a processing speed of 2.0 mm / min.

[0014]

[Embodiment 2] Another embodiment in which the electric discharge machining electrode wire manufactured by the present invention is used for machining will be described. Cu-0.16% Zr
(Outline 2.6 mm) is used as the core material, and Zn is 0.3 m
m and a solution treatment were performed, and this was cold drawn to prepare an electrode wire for electric discharge machining having an outer diameter of 0.2 mm.

Using this electrode wire, SKD-11 (thickness 40 mm) was processed by the pulse current shown in FIG. As a result, the performance of the electrode wire manufactured according to the present invention was almost the same as that shown in Example 1.

[0016]

As described above, according to the manufacturing method of the electric discharge machining electrode wire of the present invention, the Cu--Zr alloy wire is made into Z
n or Cu-Zn alloy is plated through a molten bath and the plated Cu-Zr alloy wire is rapidly cooled to remove Zr from Cu.
Heat resistance is given by making it a solid solution inside, and then
Since cold drawing is performed, the solution treatment can be effectively realized, and the heat resistance of the electrode wire can be improved while suppressing disconnection and roughness of the processed surface.

[Brief description of drawings]

FIG. 1 shows a manufacturing apparatus that realizes the present invention.

FIG. 2 shows a waveform of a pulse current used in a test for evaluating the performance of the electric discharge machining electrode wire manufactured according to the present invention.

FIG. 3 shows the results of evaluating the performance of the electrode wire for electric discharge machining manufactured by the present invention.

[Explanation of symbols]

 1. Melting furnace 1a. Heater 2. Molten metal 3. Nipple 4. Dice 5. Coating furnace 6. Cooling water tank 7. Roll 8. Roll 9. Constant speed winder 10. Sending bobbin 11. Take-up bobbin 12. Positioning roll 13. Wire drawing machine

Claims (2)

[Claims] 1. A Cu-Zr alloy wire is used as a core material, the core material is plated through a molten bath of Zn, and the plated core material is rapidly cooled to form a solid solution of Zr in Cu. Of the electrode wire for electric discharge machining. 2. A Cu--Zr alloy wire is used as a core material, the core material is plated through a molten bath of Cu--Zn alloy, and the plated core material is rapidly cooled to form a solid solution of Zr in Cu. A method of manufacturing an electrode wire for electric discharge machining, which comprises imparting heat resistance by performing the cold drawing and then performing cold drawing.