KR950014932B1 - Method for making a thin foil strip of amorphous metals and apparatus therefor - Google Patents

Abstract

The equipment for producing magnetic thin film reduces the manufacturing cost by uniform and speedy electropolishing process. The equipment comprises: a tension controller(1) for controlling the tension of amorphous metal strip(5) supplied by coiling roll(2); an electropolisher (11) with a guide roll (4) and a cathodic plate(7); an ultrasonic wave generator (9) for agitating the electropolishing solution (8); and an ultrasonic cleaner (14) and a coiler (19).

Description

Ultra-thin method of amorphous metal strip and apparatus used therefor

1 is a schematic diagram of an apparatus for practicing the method of the present invention.

* Explanation of symbols on the main parts of the drawings

1: tension controller 2: initial amorphous strip winding roll

3: anode guide roll 4: insulated guide roll

5: side roll 6: amorphous metal strip

7: negative electrode plate 8: electrolytic polishing liquid

9: ultrasonic generator 10: water

11: electrolytic polishing container 12: water inlet

13: water outlet 14: ultrasonic cleaning tank

15: washing liquid inlet 16: washing liquid outlet

17: washing liquid 18: dryer

19: ultra-thin amorphous strip punching 20: winding speed adjusting device

The present invention relates to a method for thinning a soft magnetic amorphous strip and a device used therein. Soft magnetic amorphous strips are generally classified as iron (Fe) and cobalt. Iron-based amorphous strips are mainly used for columnar transformers due to their high saturation magnetization, whereas cobalt-based amorphous alloys are used mainly for high-frequency magnetic core materials due to their low magnetic losses and high permeability.

Among Co-based alloys, for example, Co-Fe-Si-B amorphous strips with magnetostriction of O are used as high frequency magnetic core materials in the region of 100 kHz, but the thickness of such amorphous strips is reduced to several tens of micrometers in the current 20 ㎛ range. If possible, the service area may be extended to 1 MHz.

On the other hand, the energy loss of magnetic core material is expressed as the sum of hysteresis loss and eddy current loss, and the eddy current loss P occupies a larger part in the high frequency region. This eddy current loss (P) can be expressed as P = k (π ² , d ² , Bo, f ² ) · ρ ^-1 (where k is a constant, d is the thickness of the material, Bo is the magnetic flux density, and Frequency).

According to the above equation, when the magnetic flux density Bo is constant as the frequency f increases, the thickness of the material has an absolute effect on the P. Therefore, reducing the thickness of the amorphous strip as a material can minimize the eddy current loss.

The thickness of the amorphous strip that can be produced by the conventional amorphous strip casting method is about 20 μm, and if it is reduced further, a large amount of pores are generated and cannot be used.

Recently, Masaki Yagi et al. Reported that in order to cast extreme amorphous strips, the amorphous strips were cast in vacuum to reduce the thickness to 3 to 10 μm, which can be used as a high frequency magnetic core material in the 1 MHz region. (Japanese Metal Society Bulletin Vol. 31, No. 31 (1992) P 991).

However, such a manufacturing method firstly increases the manufacturing cost due to the inconvenience and complexity of making a large casting apparatus into a high vacuum atmosphere, and secondly, it is difficult to increase the capacity because it casts an amorphous strip in a closed container. Third, since it is attached very thinly to the surface of the cooling roll (casting medium) and casts, there are various problems of lighting that is difficult to peel off from the roll surface.

Accordingly, an object of the present invention is to provide an improved ultra-thin method of amorphous metal strip that solves the above problems.

Another object of the present invention is to provide an amorphous metal strip thinning apparatus suitable for carrying out such a method.

According to one aspect of the present invention, an electrolytic polishing of an amorphous metal strip in an electrolytic polishing container containing an electrolytic polishing liquid is carried out by electrolytic polishing at a current density of 35-40 A / dm 2, and the ultrathin amorphous metal strip is cleaned by the electrolytic polishing. A method of ultrathinning an amorphous metal strip is provided, which comprises removing the electrolytic polishing current by passing through the contained ultrasonic cleaning bath, followed by drying and winding up.

On the other hand, according to another aspect of the invention, the tension regulator (1) for adjusting the tension of the amorphous metal strip (5) supplied from the amorphous strip winding roll (2); Supplying a positive current to the amorphous metal strip (5), the organic insulating coating guide rule (4) and the negative electrode plate (-) (7) is provided in parallel with at least one set, electrolytic polishing liquid (8) filled with the inside Container 11; An ultrasonic generator (9) installed around the electrolytic polishing container (11) with water (10) therebetween to generate ultrasonic waves so as to stir the electrolytic polishing liquid (8); An ultrasonic cleaning tank (14) filled with a cleaning liquid therein to remove the electropolishing residue of the ultra-thin non-woven metal strip used from the electrolytic polishing container (1); Drying means 18; And winding means 19; Provided is an amorphous metal strip ultra-thin device comprising a.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is an example of an apparatus for carrying out the method of the present invention, in which a tension regulator 1 is connected to a winding roll 2 of an ultra-thin initial amorphous metal strip 5, wherein the amorphous metal strip 5 is It is continuously connected to a series of insulating guide rolls 4 installed in the electrolytic polishing container 11 through the positive electrode guide roll 3.

In addition, in the electropolishing vessel 11, the negative electrode plate 7 and the insulating coated guide roll are positioned at a predetermined interval. Reference numeral 8 is an electrolytic polishing liquid. An ultrasonic generator 9 is installed outside the electrolytic polishing vessel 11, and water 10 is filled between the outer wall of the electrolytic polishing vessel 11 and the inner wall surface of the ultrasonic generator 9. Inflow from the inlet 12 is to flow through the outlet (13).

The ultrasonic cleaning tank 14 filled with the cleaning liquid 17 is disposed near the electrolytic polishing container 11, and the strip 5 having the electrolytic polishing container 11 is ultrasonic cleaning tank 14 through a guide roller. It is supposed to pass. The ultrasonic washing tank 14 and the winder 19 are respectively provided with a dryer 18 for the next process.

In the device configured as described above, the amorphous metal strip (5) supplied from the amorphous strip winding roll (2) is tensioned by the tension regulator (1), passing through the positive electrode guide roll (3) electrolytic polishing vessel (11) It flows into you.

The amorphous metal strip 5 introduced into the electrolytic polishing container 11 is guided to the guide roll 4 and is ultra-thinned while passing through the electrolytic polishing liquid.

The insulated guide roll 4 is rotatable by the bearing to facilitate the progression of the strip 5 and to supply (+) current to the amorphous metal strip 5 by connecting (+) power from the outside. It is also coated with an organic insulating coating so that no current flows with the negative electrode plate 7.

The electropolishing liquid 8 varies depending on the type of the amorphous metal strip to be ultra-thin, but is mostly a high viscosity material. If you sign it in more detail:

In other words, electrolytic polishing proceeds through two stages: formation and destruction of oxide layer on the surface of anode and concentration polarization.

When a current is supplied between the anode amorphous metal strip 6 and the anode plate 7, a passivation film is formed on the surface of the strip to increase the voltage, and oxygen film is generated at the uneven portion where the passivation film is thinly formed, thereby destroying the film. As the accumulation of metal ions released from the uneven portion during the dissolution process continues, the concentration polarization effect increases and the thinning of the amorphous metal strip proceeds. In order to achieve a good concentration polarization effect, the viscosity of the electropolishing solution is high, so that the dissolved metal ions are accumulated without being released into the solution, and for this purpose, the viscosity of the solution is preferably high. However, if the viscosity of the solution is too high, it is difficult to stir the solution by the air spray method or the mechanical stirring method in the existing solution, and thus it is not uniformly polished due to the local concentration difference of the solution. In order to solve this problem, the electropolishing efficiency can be increased by agitating the solution using the ultrasonic generator 9.

The amorphous metal strip polished by the above process is introduced into the ultrasonic cell chuck tank 14 via the anode guide roll 3 and the guide roll 5 to remove the electrolytic polishing current. Acetone and alcohol are suitable as the washing liquid. The washed strip is wound by an ultra-thin amorphous strip winding roll built in the winding speed adjusting device 20 which is capable of adjusting the speed after drying the washing liquid in the dryer 18.

As described above, in the present invention, while continuously passing the amorphous strip inside the electrolytic polishing bath, the polishing is uniformly performed by the ultrasonic generator, and the conventional casting apparatus is performed by the winding and the winding in the washing and winding apparatus in the ultrasonic cleaning tank continuously. Amorphous strips produced by the company are continuously and quickly electropolished to easily thin the thickness of the strip.

Hereinafter, embodiments of the present invention will be described.

Cobalt (Co) -based amorphous metal strips were extremely thin by electrolytic polishing conditions shown in Table 1 using the apparatus shown in FIG. Electrolytic polishing solution was composed of 70% phosphoric acid, 10% distilled water, 5% glycerin, 5% chromic acid, 10% sulfuric acid. Ultrathin strips showed good polishing strips at very low current densities of 10-20 (A / dm²) and 7-8 μm within 2-3 minutes at 35-40 (A / dm²). It was possible to reduce the thickness and the surface of the strip was very beautiful, and no other hole was observed in the local application (see Table 1). However, at 50 A / dm 2, very small holes appeared in the strip. This shows that 35-40 (A / dm 2) is appropriate for the current density.

TABLE 1

As described above, according to the present invention, by using a continuous electropolishing apparatus adopting the first wave, the amorphous metal strip having a thickness of several tens of micrometers is ultra-thin at a high speed up to several micrometers, thereby increasing the use of the high frequency region. It is.

Claims (2)

Electrolytic polishing the ultra-thin amorphous metal strip with an electric current density of 35-40 A / dm 2 under the generation of ultrasonic waves in an electropolishing vessel contained in electropolishing; Removing the electropolishing currents by passing the ultra-thin amorphous metal strip through the ultrasonic cleaning tank containing the cleaning solution; Drying the strip from which the electropolishing current has been removed; And winding it up; Ultrathin thinning of the amorphous metal strip comprising a. A tension regulator 1 for adjusting the tension of the amorphous metal strip 5 supplied from the amorphous strip winding roll 2; Supplying a (+) current to the amorphous metal strip (5), the organic insulating coating guide roll (4) and the negative electrode plate (-) (7) is provided at least one set, the electrolytic polishing liquid (8) filled inside Polishing vessel 11; An ultrasonic generator (9) installed around the electrolytic polishing container with water (10) therebetween to generate ultrasonic waves to stir the electrolytic polishing liquid (8); An ultrasonic cleaning tank (14) filled with a cleaning liquid therein to remove electrolytic polishing currents of the ultra-thin amorphous metal strips transferred from the electrolytic polishing container (11); Drying means (18) for drying the strip leaving the ultrasonic cleaning tank; And winding means 19 for winding the dried ultrathin strip. An amorphous metal strip ultrathin device comprising a.