JPH045735B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an electrode wire suitable for wire-cut electric discharge machining, and more specifically, to an alloy wire for wire-cut electric discharge machining electrode wire containing 30 to 40% by weight of Zn and 0.05 to 2% by weight of B, with the balance being Cu. It is something. The wire-cut electrical discharge machining method generates electrical discharge between the workpiece and a linear machining electrode (hereinafter simply referred to as electrode wire), and moves the electrode wire and workpiece relatively. This method cuts a workpiece into a desired shape, and is a conventional method. In this wire cut electric discharge machining method, a long wire having a diameter of usually 0.05 to 0.3 mm is prepared as a linear electrode wire, and new wires are sequentially supplied to the electric discharge machining part. In the electric discharge machining method, the suitability of the electrode wire used has a direct and significant effect on machining speed, machining accuracy, surface quality of the workpiece surface, etc., so there is a strong demand for the use of suitable materials. . In general, the requirements for this electrode wire are: (1) Machining speed: Wire-cut electric discharge machining generally does not necessarily have a fast machining speed, so it must be possible to increase the machining speed even a little. (2) Dimensional accuracy and surface quality of the workpiece: It must be possible to process the workpiece with good dimensional accuracy and without causing surface roughness. (3) Workability: If the electrode wire breaks during cutting work, workability will be significantly impaired, so the occurrence of breakage during this work should be low. In addition, in recent years, automatic wire connection mechanisms have been added to processing equipment, which has been effective in improving workability, but for this purpose, it is desirable that the electrode wires be free of wires. (4) Processability into thin electrode wires: Due to the ever-increasing demand for high precision, thin electrode wires are becoming desirable, and at this time, they must be easy to process, such as wire drawing, on an industrial scale. etc. are listed. To further explain the above requirements for the electrode wire, the machining speed must be such that a sufficiently stable electrical discharge is generated between the electrode wire and the workpiece, and the electrode material does not adhere to the workpiece. Although it has been found that it is effective to prevent short circuits by using wires, there is no electrode wire that can achieve this effect, and the emergence of such a material has been eagerly awaited. In addition, in order to obtain the dimensional accuracy of the workpiece, it is necessary to maintain the dimensional accuracy of the diameter of the electrode wire and to apply sufficient tension to ensure that the electrode wire is used in a taut state.
It is required that the wire is hard to break under this tension. Next, regarding surface properties such as rough skin, it is necessary to generate a uniform and stable discharge, and it is also desirable that there be no adhesion of electrode materials. In addition, wire breaks during cutting can be caused by short circuits, uneven discharge, or applied tension between the electrode wire and the workpiece, so from these points of view, the dimensional accuracy of the electrode wire itself and stable discharge performance are important. , high thermal conductivity and high tensile strength are required. In addition, the alloy raw materials are inexpensive so that the price does not become expensive, and 0.05 to 0.3 mm is suitable for electrodes for electrical discharge machining.
It is also necessary to have good wire drawability into thin wires up to the diameter of φ. Conventionally, copper wire, brass wire (Cu-35%Zn), tungsten wire, etc. have been used as electrode wires for wire cut electrical discharge machining, but these do not necessarily meet the above requirements in the following points. Nakatsuta. That is, copper wire has drawbacks such as not having very high strength, being easily broken, and being generally inferior to brass wire in terms of processing speed. In addition, although brass wire has improved machining speed over copper wire, it is still not sufficient as some adhesion occurs at high machining speeds, and the dimensional accuracy and surface condition of the workpiece are not necessarily good. In addition, it has other drawbacks such as not being necessarily satisfactory in terms of workability. Furthermore, tungsten wire is difficult to draw, is an expensive material, and has poor electrical discharge machinability. This invention was discovered as a result of various studies in view of these problems, and provides an alloy wire suitable as an electrode wire for wire-cut electrical discharge machining. That is, this invention contains 30 to 40% by weight of Zn and 0.05 to 2% of B.
% by weight, with the remainder being Cu. In this invention, Zn is effective in increasing the processing speed as described above, and also contributes to increasing the strength of the alloy wire. Therefore, the reason why the Zn content is specified as 30 to 40% by weight is that the higher the Zn content, the more effective it is for the stability of electrical discharge machining, and if the Zn content is less than 30% by weight, the above effect will be small. Further, even if the amount exceeds 40% by weight, the effect within the above range cannot be further improved, and on the contrary, it becomes extremely difficult to draw a wire into a thin wire, which is undesirable. In addition, the use of B, together with the presence of Zn, reduces the adhesion of the electrode to the workpiece, speeds up machining speed, and improves strength, making it easier to obtain linearity without reducing strength. As a result, it has a significant effect on improving electrical discharge machining speed, improving dimensional accuracy, and improving workability. Furthermore, the addition of B is less likely to impair thermal conductivity when added to brass, and wires are less likely to break due to short circuits between the electrode wire and the workpiece. From the perspective of manufacturing electrode wires, the addition of B is particularly effective in improving the hot workability and cold drawability of brass with a high Zn content, which is advantageous for the stability of discharge characteristics, and is effective for thinning wires. effect. The amount was specified to be in the range of 0.05 to 2% by weight.
This is because if the content is less than 0.05% by weight, the effect will be small, and if it is contained in an amount exceeding 2%, it will only cause segregation of B or impair workability, making it difficult to achieve the above-mentioned further improvement effect. In addition, in the alloy wire of this invention, Sn, Ag,
There is no problem in containing one or more elements such as Mg, Si, Al, or other elements that act as deoxidizing agents, as long as the total does not exceed 0.5% by weight, and on the contrary, it may increase strength. In some cases, it is preferable because it exhibits the following effects. As detailed above, the wire-cut alloy wire for electrical discharge machining electrode wire of the present invention has a high processing speed during electrical discharge machining, has excellent dimensional accuracy and surface quality of the workpiece, and can be easily processed into fine wires. In addition, it is very useful as an electrode wire for processing various workpieces because it has good workability with few wire breaks during processing. The present invention will be explained in detail below with reference to Examples. Example 1 Ordinary electrical copper ingots, Zn, and Sn are in the form of B,
Al is made by semi-continuously casting an alloy material with the composition shown in Table 1 using a master alloy, hot extruding it into a rough drawn wire of 8 mmφ, and then peeling it during the wire drawing process.
After intermediate heat treatment with 2.6mmφ, 0.15mmφ
An electrode wire was manufactured. In addition, in order to improve the workability of automatic wire connection, a light electrical heating treatment was performed at the final stage of the wire drawing process. Additionally, in Inventive Examples Nos. 1 to 4, there was little decrease in strength during this treatment, and electrode wires with excellent linearity without wire distortion were obtained while maintaining a tensile strength of 100 Kg/mm ² or more. When trying to obtain sufficient linearity with other electrode wires, strength decreased or linearity was difficult to obtain. Further, as a conventional example and a comparative example, electrode wires were made using the same method using alloy materials having the compositions shown in Table 1. Problems in drawing the obtained electrode wires are also listed in Table 1.

[Table] From the above contents and the above table, it was recognized that the electrode wire of the composition of the present invention can be easily processed into fine wires and can be produced industrially advantageously. Example 2 Using the 0.15 mmφ electrode wire obtained in Example 1, the thickness was
Wire cut electric discharge machining was performed using 50 mm SKD-11 as the workpiece, and the results are shown in Table 2. The processing speed was expressed as the ratio of the processing cross-sectional area per unit time (that is, the product of the processing feed rate and the thickness of the workpiece), with the brass wire (No. 6) being 1.00.

【table】

[Table] From the above table, it was confirmed that by using the electrode wire of the present invention, it was possible to perform processing with less adhesion of electrode material, good processing speed, and excellent surface texture and dimensional accuracy. It was also found that it is easy to manufacture and inexpensive, has fewer troubles such as wire breakage during use, and has excellent workability in automatic wire connection. As detailed above, the electrode wire of the present invention has Zn
30 to 40% by weight, preferably 35 to 38% by weight.
This electrode wire for wire cut electric discharge machining is characterized by containing 0.05 to 2% by weight of B, with the remainder being Cu, so it is capable of wire cut machining with excellent machining speed, machining accuracy, and machined surface quality. , which can be used industrially with great benefits.

Claims (1)

[Scope of Claims] 1. Wire-cut electrical discharge machining electrode wire characterized by containing 30-40% by weight of Zn and 0.05-2% by weight of B, with the remainder being Cu. 2. 30-40% by weight of Zn and 0.05% by weight of B. ~2% by weight, and one or more of Sn, Ag, Mg, Si, and Al in a range not exceeding 0.5% by weight in total, with the remainder being Cu for wire cut electric discharge machining. electrode wire.