JPH0560811U - Wire for wire saw - Google Patents

Abstract

(57) [Abstract] [Purpose] By improving the surface roughness of the undercoating wire, variation in the thickness of the copper plating layer is reduced, and the appearance of partial wire exposed areas due to cutting wear is suppressed, which is good for a long time. To obtain a wire for a wire saw that can maintain a high cutting efficiency and cutting accuracy and extend the service life. [Structure] Hardness XH is CuH <XH <on the outer periphery of the steel wire.
An intermediate plating layer having a thickness of 1 to 3 μm, which is SH (however, CuH: copper plating layer hardness, SH: steel fine wire hardness) is formed,
Form a copper plating layer with a thickness of 3 to 8 μm on the outer periphery of the wire diameter
A wire saw wire having a diameter of 0.10 to 0.30 mm is constructed.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a wire for a wire saw used for cutting hard materials such as semiconductors, ceramics and cemented carbide, and particularly for cutting magnetic heads such as VTRs and ATRs that require precise surface accuracy. It relates to a suitable wire for a wire saw.

[0002]

[Prior Art]

 The wire saw is a wire saw that cuts by running a wire together with abrasive grains for cutting, generally abrasive grains such as silicon carbide powder, diamond powder and the like while being pressed against an object to be cut.

Since the above-mentioned wire is required to have a strength capable of withstanding the tension applied at the time of cutting, a high tensile strength wire, generally a hard steel wire rod, a piano wire rod or the like is used. However, since the surface of these wires is hard and smooth, there is a problem that the abrasive grains are not brought into the object to be cut, the cutting speed cannot be improved, and the cutting efficiency is poor. Was there.

In view of the above problems, in recent years, a layer of copper or tin is provided on the surface of a piano wire, and by holding the abrasive grains in this relatively soft layer, it is possible to improve the carry-in of the abrasive grains to the object to be cut. A wire for a wire saw has been proposed (for example, Japanese Laid-Open Patent Publication No. 54-21692).

FIG. 6 shows an outline of a general manufacturing process of the wire for the wire saw. In the figure, 20 is a high tensile strength wire having a wire diameter of 0.8 to 1.2 mmφ, and a plating layer 21 of copper, tin or the like is formed on the outer periphery of the wire 20. Then, by wire drawing, a wire saw wire 22 having a wire diameter of 0.10 to 0.30 mm is obtained.

The above manufacturing method will be described more specifically with reference to FIG. In the figure, a high tensile strength wire (for example, SWRS80A) 20 having a wire diameter of 0.8 to 1.2 mmφ is heat treated (patented) through a heating furnace 8 and a lead quenching tank 9, and then an electrolytic acid cleaning tank 10, Pre-treatment is carried out through the washing tank 11, the alkaline washing tank 12, and the washing tank 11, and then a plating layer 21 having a thickness of 30 to 40 μm is formed in the copper sulfate plating bath 15. It is wound up in. Then, this wire 23 is guided to a plurality of dies 19 of the continuous wire drawing machine 18, and wire drawing is performed at a workability of 94 to 98% to obtain a wire diameter of 0.10 to 0.30 mmφ having a plating thickness of 3 to 8 μm. A wire 22 for a wire saw is obtained.

[0007]

[Problems to be solved by the device]

 When the hard material is cut using the wire saw wire 22 obtained as described above, the wire itself is naturally worn. It should be noted that when the wear progresses and the base material is exposed, not only the cutting efficiency is deteriorated, but also the cutting force becomes uneven and the surface state of the object to be cut is roughened. In the wire 22, such a phenomenon occurs early, and the service life of the wire saw wire is shortened. Therefore, it is not suitable as a wire saw wire for cutting a magnetic head such as a VTR or ATR, which requires a particularly precise surface accuracy.

The inventor of the present invention tried various tests and analyzes in order to explore the factors of the above conventional problems, and as a result, obtained the following findings. That is, when the cross section of the wire for the wire saw 22 is observed with a microscope, as shown in FIG. 8, irregularities are observed on the entire circumference of the surface of the plating base wire 20, and when the surface roughness is measured, the maximum height Rt is Rt. The value was 3.0 to 4.5 μm. By the way, in the above wire saw wire 22, the variation in the thickness of the plating layer becomes large, and the protrusions on the surface of the plating base wire, that is, the thin portions of the plating layer, disappear early due to wear, and the wire surface is exposed. It was supposed to be done. Furthermore, when pursuing the factors that make the surface roughness rough, in order to improve the plating efficiency and the lubricity of wire drawing, the plating layer formed before wire drawing rather deteriorates the quality of the wire for wire saw. I found out that it was a factor. In other words, when thinning a wire saw wire with a soft plating layer on the outer periphery compared to high tensile strength wire such as steel fine wire with multiple dies, the internal high tensile strength wire is eccentric when passing through each die. As a result, the wire is pulled out while being formed, so that the wire surface has irregularities.

The present invention has been made in view of the above problems, and improves the surface roughness of the plating base wire and minimizes the variation in the thickness of the plating layer, thereby rapidly deteriorating the cutting accuracy. The purpose is to obtain a wire for a wire saw that has a long service life.

[0010]

[Means for Solving the Problems]

 In order to achieve the above object, the wire for a wire saw of the present invention is a wire saw wire having a wire diameter of 0.10 to 0.30 mmφ formed by forming a copper plating layer on the outer periphery of a steel thin wire. An intermediate plating layer having a hardness XH of CuH <XH <SH (where CuH: copper plating layer hardness and SH: steel wire hardness) is formed between the plating layer and the plating layer.

In the above structure, nickel, chromium, and zinc plating layers can be specifically applied to the intermediate plating layer having hardness XH. However, if the thickness is too small, the surface of the plating base wire is drawn by wire drawing. Since the roughness becomes large and the variation in the thickness of the plating layer becomes large, the intended purpose cannot be achieved.On the other hand, if it is too large, it will be inferior in strength when commercialized, so the range of 1 to 3 μm is optimal. Is.

[0012]

[Action]

 The wire for a wire saw according to the present invention has an intermediate plating layer between the steel fine wire and the copper plating layer, has a very small surface roughness, and the surface roughness of the steel fine wire is smaller than that of the conventional one. Even when the thickness of the plating layer becomes substantially uniform and the copper plating layer gradually wears, the degree of wear is substantially uniform, and it is possible to prevent the partial exposed portion from appearing early. Therefore, it becomes possible to form a cut surface having good surface accuracy on the object to be cut for a long period of time.

[0013]

【Example】

 1 is a schematic sectional view of a wire for a wire saw according to a preferred embodiment of the present invention. In the figure, 1 is a thin steel wire, a nickel plating layer 2 having a thickness of 2.0 μm is provided on the surface thereof, and a copper plating layer 3 having a thickness of 5.0 μm is formed on the upper surface thereof to form a wire saw. The wire 4 is configured.

FIG. 2 shows an outline of a manufacturing process of the wire 4 for the wire saw. In the figure, 5 is a steel wire (Hv 650 to 750) having a wire diameter of 0.95 mmφ, a nickel plating layer (Hv 450 to 550) 6 having a thickness of 12 μm is formed on the outer periphery thereof, and then the thickness is formed on the outer periphery thereof. A 30 μm copper plating layer (Hv 200 to 300) 7 is formed. Then, wire drawing is performed with a workability of 96.2% to obtain a wire saw wire 4 having a wire diameter of 0.20 mmφ.

The above manufacturing method will be described more specifically with reference to FIG. In FIG. 3, a steel wire (for example, SWRS80A) 5 having a wire diameter of 0.95 mmφ is heat-treated (patented) through a heating furnace 8 and a lead quenching tank 9. Then, this wire is subjected to a pretreatment such as washing to form a nickel plating layer having a thickness of 12 μm in a nickel sulfate plating bath 13 and then washed in a washing bath 11, followed by copper pyrophosphate plating bath 14 and sulfuric acid. A copper plating layer having a thickness of 30 μm is formed in the copper plating bath 15, and the water is washed by the winder 17 through the washing tank 11. Then, the wire 16 was drawn by a continuous wire drawing machine 18 with a workability of 96.2%, and a nickel plating layer of 2.0 μm and a copper plating layer of 5.0 μm with a wire diameter of 0.20 mm φ was obtained. A wire 4 for a wire saw was obtained. The surface roughness of the plating base wire of the wire 4 for the wire saw was measured and found to be Rt 1.8 μm. In the figure, 10 is an electrolytic acid cleaning tank, and 12 is an alkaline cleaning tank.

Next, the wire saw wire shown in Table 1 was manufactured, and the single crystal ferrite that is the material of the video head was cut using this wire, and the cutting efficiency and the accuracy of the cut object were measured. The results are shown in FIGS. 4 and 5.

[0017]

[Table 1]

In the above test, each wire saw wire had a copper plating layer thickness of 5 μm and a wire diameter of 0.2 mmφ and was cut at a wire wire speed of 5 m / sec and a load of 1 kg.

Test No. D is a conventional wire saw wire, and the plating base wire was exposed early during the test, and the cutting efficiency and the cutting accuracy were reduced early. In Test No. C, the thickness of the intermediate plating layer was increased and the surface roughness Rt of the plating base wire was made extremely small, but fracture occurred during the test. As is clear from the above test results, the wire for a wire saw of Test Nos. A and B, which is an embodiment of the present invention, can maintain good cutting efficiency and cutting accuracy over a long period of time as compared with Conventional Example D. It is a thing.

[0020]

[Effect of the device]

 Since the wire for a wire saw of the present invention has the above-mentioned structure, it has a copper plating layer with a uniform thickness, can maintain good cutting efficiency and cutting accuracy for a long time, and can prolong its service life remarkably. Therefore, particularly when used for cutting a magnetic head such as a VTR or ATR which requires precise surface accuracy, a remarkable effect is obtained.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing an embodiment of a wire for a wire saw according to the present invention.

FIG. 2 is a schematic process drawing of a wire for a wire saw of the present invention.

3 (a) and 3 (b) are schematic explanatory views of an apparatus showing a manufacturing process of a wire for a wire saw of the present invention.

FIG. 4 is a graph showing the relationship between the total cutting area of a wire for a wire saw and the cutting efficiency.

FIG. 5 is a graph showing the relationship between the total cutting area of a wire for a wire saw and the cutting accuracy.

FIG. 6 is a schematic process drawing of a conventional wire for a wire saw.

7 (a) and 7 (b) are schematic explanatory views of an apparatus showing a conventional wire saw wire manufacturing process.

FIG. 8 is a schematic cross-sectional view showing a conventional wire for a wire saw.

[Explanation of symbols]

 1 Steel fine wire 2,6 Nickel plating layer 3,7,21 Copper plating layer 4,22 Wire saw wire 5,20 Steel wire 8 Heating furnace 9 Lead quenching tank 10 Electrolytic acid cleaning tank 11 Rinsing tank 12 Alkali cleaning tank 13, 14,15 Plating bath 16,23 Wire 17 Winder 18 Continuous wire drawing machine 19 Dies

Claims (2)

[Scope of utility model registration request] 1. A wire saw wire having a wire diameter of 0.10 to 0.30 mmφ formed by forming a copper plating layer on the outer periphery of a steel thin wire, wherein the hardness XH is C between the steel thin wire and the copper plating layer.
uH <XH <SH (however, CuH: copper plating layer hardness,
A wire for a wire saw, characterized in that an intermediate plating layer having a hardness of SH: steel fine wire is formed. 2. The thickness of the copper plating layer is 3 to 8 μm,
The wire for a wire saw according to claim 1, wherein the intermediate plating layer has a thickness of 1 to 3 µm.