JPH01249A - Ultra-thin amorphous alloy with high magnetic permeability and low iron loss - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Object of the invention] (Industrial application field) This invention is applicable to transformers, noise filters, saturable reactors, ultra-small inductance elements for reducing spike noise, zero-phase current transformers, magnetic heads, etc. As the performance of electronic equipment increases, requiring high magnetic permeability and low iron loss at high frequencies, the magnetic components used as important functional parts also need to have higher performance. Therefore, the magnetic materials used in these magnetic parts are required to have excellent magnetic properties, and in particular, materials with high magnetic permeability are required for many magnetic parts such as current sensors such as zero-phase current transformers and noise filters. is valid.

First, the noise filter will be explained.

Switching power supplies are widely used as stabilized power supplies for computer peripherals and general communication equipment. With switching power supplies, when power supply voltage is input to the equipment from the power line, noise is generated in addition to the specified power supply voltage. Voltage may enter the device and be input.Furthermore, high-frequency noise whose fundamental frequency is the switching frequency, or noise in the MHz range generated from a load, such as the logic circuit of a personal computer, poses a problem.

In order to reduce these conductive noises, a common mode choke coil as shown in FIG. 1, for example, is used as a noise filter.

In FIG. 1, a choke coil 1 has a pair of windings 3a and 3b attached to a magnetic core 2 so that the magnetic flux caused by the reciprocating current cancels out.

Capacitors 4a, 4b, and 4c are connected between capacitors 3b, and the connection point of capacitors 4b and 4c is grounded. When this filter is inserted into a power supply line, the magnitude of the noise output voltage relative to the noise input voltage is related to the magnetic permeability of the magnetic core, and the larger the magnetic permeability, the smaller the noise output voltage becomes. Furthermore, it is necessary to function effectively not only in a low frequency region but also in a high frequency region of IMHz or higher, and for this purpose, the frequency characteristics of magnetic permeability also need to be good.

Conventionally, ferrite has been used as a material constituting the magnetic core of a common mode choke coil. However, recently noise regulations have become stricter in a relatively low frequency range (10 to 450kHz), and ferrite is said to be unable to sufficiently reduce noise due to its low magnetic permeability in the low frequency range. There are drawbacks. Therefore, there has been a need for a magnetic core that has high magnetic permeability, particularly in the low frequency range, and excellent frequency characteristics.

Furthermore, in recent years, switching power supplies incorporating magnetic amplifiers have been widely used.

The main part constituting this magnetic amplifier is a saturable reactor, and a magnetic core material with excellent square magnetization characteristics is required. Conventionally, Sendelta (trade name), which is made of an Fe--Ni crystalline alloy, has been used as such a magnetic core material.

However, although center delta has excellent square magnetization characteristics, at high frequencies of 20 kHz or higher, the coercive force increases, eddy current loss increases, and heat is generated, making it unusable. For this reason, the switching frequency of a switching power supply incorporating a magnetic amplifier has been limited to 20 kHz or less.

On the other hand, in recent years, combined with the demand for smaller and lighter switching power supplies, there has been a demand for higher switching frequencies. 5
The frequency is limited to 00 kHz, and there is a desire for a material that is compatible with higher frequencies for the negative layer. Also, the DC-
Similarly, reducing iron loss is an important issue for magnetic components used in DC converters.

On the other hand, it is generally known that eddy current loss can be suppressed and high frequency characteristics can be improved by reducing the plate thickness of metal materials. Amorphous alloys, which have good high frequency properties among metal materials, are usually produced by a liquid quenching method, and a single roll method (FIG. 2) is usually used as the means for this.

There is a practical problem if there is not a certain width, and under conventional conditions, the limit of the thickness of a ribbon with a width of 2 or more is about 11 to 12 μm, and such a ribbon has relatively many pinholes. However, there were problems in terms of practicality, including the need for higher frequencies.

(Problem to be solved by the invention) As described above, high magnetic permeability and low core loss are required up to high frequencies (to Ilz range) for various magnetic cores, and these are required for high efficiency, compact and lightweight equipment, and small and light cores. This leads to improvements in technology and performance.

The object of the present invention is to provide an ultra-thin amorphous alloy having a plate thickness of 10 μm or less in a good condition without pinholes etc. so as to satisfy the above-mentioned magnetic properties.

[Structure of the Invention] (Means and Effects for Solving the Problems) The ultrathin amorphous alloy of the present invention has the general formula % Y selected from Cr+W, Cr+Mo+W; at least selected from Si, B, P, and C. It is an ultra-thin amorphous alloy with high magnetic permeability and low iron loss, which is an alloy of one or more types of 0.01X≦0.1, 15≦2≦30, and has a plate thickness of 10 μm or less.

The reasons for limiting the composition of the alloy of the present invention will be explained below.

M is an element that is effective in lowering the viscosity when melting the alloy, improving wettability with rolls, and improving the surface properties of the alloy, but if it is too small, the effect will not be obtained, and on the other hand, if it is too large, the Curie temperature will increase. Therefore, the range of X that defines M is set to 0.0.
It was set as 1 to 0.1.

Preferably it is 0.015 to 0.07, more preferably O.02 to O.Q55. In particular, M is Cr alone,
Combinations of Cr+Mo, Cr+W are preferred, and Fe
It is possible to replace up to 50 atomic % of Ni with Ni.

Y is an element necessary for amorphization, but if it is less than 15 atom % or exceeds 30 atom %, amorphization becomes difficult, so its amount is set to 15 to 30 atom %. Preferably 17 to 27 at%, more preferably 17 to 2
It is 5 atom%. Especially SL.

When the amount of C is less than 5 at% and exceeds 20 at%, or B
If the amount of P is less than 10 atomic % and exceeds 25 atomic %, the surface properties of the obtained alloy will deteriorate, making it unfavorable for extremely thinning of 10 μm or less.
Preferably, 10≦(B, P)≦25. More preferably 7
≦(St, C)≦15, 10≦(B, P)≦20.

The ultrathin amorphous alloy of the present invention is manufactured by the following method.

That is, when manufacturing an amorphous alloy ribbon by jetting a molten alloy having the alloy composition of the present invention from a nozzle onto the surface of a rotary cooling body and ultra-quenching it, the molten alloy spouted from the nozzle comes into contact with the rotary cooling body. The atmosphere during the process is an inert gas atmosphere of less than 60 torr or 0.01 t.
Manufactured in a reduced pressure atmosphere below orr.

Here, under reduced pressure or inert gas atmosphere, 1O
-2 torr, 80 torr or less is especially important for 1.
This is because when producing a wide ribbon of 5 mm or more, a thin strip with excellent surface properties and no pinholes can be obtained; outside this range, undulations (unevenness) may occur in the width direction, there may be many pinholes, etc. A thin ribbon of 10 μm or less may not be obtained. Note that the inert gas is preferably He or Ar, and He is most preferred.

In addition, the roll material is F since the alloy composition of the present invention is Fe-based.
If an e-based alloy or a Cu-based alloy (such as brass) is used, a plate with good surface properties and an extremely thin thickness can be obtained.

Further, the shape of the slit at the tip of the nozzle, a in FIG. 3, determines the width of the obtained ribbon, and can be set to an appropriate value of 2II1 or more. In addition, b is an important value that determines the thickness of the ribbon, and is preferably 0.2 mm or more, and O, 1
5m5+ or less is preferable for producing ultra-thin ribbons.

The peripheral speed of the roll should be 10■/S or more, and 20II/S or more.
s or more is preferable.

The injection pressure may be 0.05 kg/cj or more to produce an ultra-thin ribbon, preferably 0.025 kg/cj or less, and more preferably 0.020 kg/cd or less, but 0.001 kg/cj. If it is less than cj, it is difficult to inject molten metal.

The amorphous alloy ribbon obtained as described above is wound or laminated to form the shape of a magnetic core, subjected to strain relief heat treatment, and then cooled. The cooling rate is 0.5 deg/-
- It may be within the range of quenching in water, preferably 1 to 50 d.
eg/-. After this, heat treatment in a non-magnetic field or in a magnetic field (heat treatment in the axial direction of the ribbon, in the width direction, in the thickness direction, and in a rotating magnetic field) may be further added. The atmosphere in these heat treatments is not particularly limited, and may be an inert gas such as N2°Ar, a vacuum, a reducing atmosphere such as N2, or the atmosphere.

(Example) The present invention will be explained in detail below.

Example 1 (Fe Cr Mo ) SiG, 9
B 0.02 Q, 02 77 10B1
Three alloy compositions were prepared and melted to obtain a master alloy for producing an amorphous alloy.

The slit shape of the nozzle used was 5 mg x 0.15 mw, and when producing an amorphous alloy, Fe was used as the roll material, a single roll device was placed in a chamber, and after preliminary evacuation to 5 x 10''5 torr, He gas was sealed up to 30 torr. . Roll circumferential speed 57m/s
ee and injection gas pressure of 0.02 kg/C-, the molten metal was ultra-quenched to obtain a long ultra-thin amorphous alloy thin sheet with a thickness of 4.8 to 5.2 μm and a width of 4°81-mm with good surface properties. I got the belt.

Under vacuum evacuation condition (5X1G'torr) using similar means.
), a similar long ultrathin ribbon without pinholes was obtained.

For comparison, F e 7yS t t. We tried to make the alloy composition 813 extremely thin using the same manufacturing conditions, but the molten metal could not be ejected, and when we changed the slit size, the result was approximately 1.
The minimum value was 2 μm.

The thin ribbon obtained in the example was formed into a toroidal shape, subjected to strain relief heat treatment, and its magnetic properties were evaluated.

F: The iron loss under the measurement conditions of I MHz and 0.1 (T) was 1.7 (V/cc), and the comparative example (7) 6
．． 2 (w/ec) l: This is reduced to about 174 compared to 2 (w/ec) l. Moreover, equivalent values were obtained even when W was used instead of Mo.

Further, the frequency characteristic of magnetic permeability was also measured using an impedance analyzer, and it was 800 at 10 MHz, which is about 5 times higher than 150 in the comparative example.

[Effects of the Invention] As explained above, according to the present invention, an extremely thin amorphous alloy can be obtained directly from a molten state, and by using this amorphous alloy, a magnetic core with excellent high frequency magnetic properties can be obtained. , saturable accelerators, various reactors such as reactors for semiconductor circuits, noise filters (for common mode, normal mode, and high voltage pulses), main transformers, magnetic cores used in high frequencies such as magnetic heads, or sensors (current direction, pressure, etc.) ) is suitable for

[Brief explanation of drawings]

FIG. 1 is a circuit diagram, FIG. 2 is a schematic diagram of the device, and FIG. 3 is a slit plan view.

Claims (1)

[Claims] (1) General formula (Fe_1_-_xM_x)_1_0_0_-_zY_
zM: 1 type selected from Cr, Mo, W, Cr+Mo, Cr+W, Cr+Mo+W Y: At least 1 type selected from Si, B, P, C 0.01≦X≦0.1 15≦Z≦30 An ultra-thin amorphous alloy with high magnetic permeability and low iron loss, characterized by a plate thickness of 10 μm or less.