JPS5985835A - Amorphous alloy having high thermal stability, small coercive force and high squareness and saturable reactor using said alloy - Google Patents

Abstract

PURPOSE:To obtain an amorphous alloy having high thermal stability, small coercive force and a high squareness ratio by very rapidly cooling a molten Co- Fe alloy material having a specified composition contg. B and Si in a prescribed ratio as well as Ti, etc. CONSTITUTION:An alloy material having a composition represented by a general formula (Co1-x-yFexMy)100-z(SiaB1-a)z (where M is one or more among Ti, V, Cr, Mn, Ni, Y, Zr, Nb, Mo, Hf, Ta, W and a rare earth metal, 0<=x<=0.1, 0.005<=y<=0.2, 20<=z<=30, and 0.40<=a<=0.55) is melted and rapidly cooled at >=about 10<5> deg.C/sec cooling rate to obtain an amorphous alloy having superior thermal stability, <=about 0.4 Oe small coercive force even at >=about 20kHz, especially about 50kHz high frequency, and >=about 85% high squareness ratio. The amorphous alloy is suitable for use in the manufacture of a saturable reactor for a magnetic amplifier.

Description

[Detailed Description of the Invention] (Technical Field of the Invention) The present invention is an amorphous alloy, more specifically, it is used as a magnetic core material for magnetic amplifiers, etc., and has excellent low coercive force and square shape characteristics at high frequencies. It also relates to highly thermally stable amorphous alloys.

(Technical Background of the Invention and Problems Therewith) In recent years, switching power supplies incorporating magnetic amplifiers have been widely used as stabilized power supplies for computer peripherals and general communication devices.

The main part constituting this magnetic amplifier is a saturable reactor, and its iron core requires a magnetic core material with excellent square magnetization characteristics.

Conventionally, Sendelta (trade name), which is made of a pg-NL crystalline alloy, has been used as such a magnetic core material.

However, although the center delta is inferior to the square magnetization characteristic, at high frequencies of 20 KH2 or higher, the coercive force becomes large, the thin current product increases, and heat is generated, making it unusable. Therefore, switching 'with built-in magnetic amplifier'
The switching frequency of the IL source was limited to below 20 KHz.

On the other hand, in recent years, switching power supplies have become smaller and @
Along with the demand for quantification, there is a need for higher switching frequencies, but to date no satisfactory magnetic core material has been found that has a small coercive force at high frequencies and has excellent squareness and thermal stability. Not served.

As a result of extensive research in order to solve the above-mentioned problems, the present inventors have found that they contain B and St in a predetermined ratio and a predetermined atomic %, and further increase the crystal temperature (T, 2''). ) is larger than the temperature (To)
The present invention was completed based on the discovery that amorphous alloys have a low coercive force and excellent square magnetization characteristics and thermal stability at high frequencies of 20 Kl-Iz or higher.

(Object of the invention) The present invention is directed to a high frequency of 20KH2 or more, especially 50KH2.
z, its coercive force (HC) is as small as 0.4 Oersted (Oe) or less, and its squareness ratio (Br
/B l) is as large as 85% or more, and their thermal stability is excellent.

Therefore, it is an object of the present invention to provide an amorphous alloy suitable for use as a magnetic core material for a magnetic amplifier.

(Summary of the invention) That is, the amorphous alloy of the present invention has the following formula = (0'+ -
x-y ”x M, oo-z (SLalj+-(Z)
2 (where M is Ti, V, Or, Mn, Ni, Y, Zr
.

One or more elements selected from the group of Nh, MO, Hf, Ta, and W rare earth metals, and x, yz, and α are each 0<
x<;:0.1, 0.005<ykuo, 2.20<Z
It is characterized by having a composition expressed by the following relationship: 0.40<(t0.55).

In the amorphous alloy of the present invention, SL and B are necessary for amorphization, but their total amount 2 is set to 20 x 30. If 2 exceeds 30, it becomes difficult to form an amorphous material, and vice versa (if it is less than 220, the crystallization temperature (T In this respect, preferably 2 is 15 times 2
5 is practical. Furthermore, in order to obtain excellent thermal stability without impairing low coercive force and high squareness, the ratio of St and B is important, and if the ratio of SL is α, then 0.40 × α × 0.55 A range of is good. More preferably 0.45 α<
: 0.5'3 is good.

Furthermore, pg contributes to increasing the magnetic flux density of the obtained alloy, and its composition ratio X is set in the range of o < x < o, t. If X exceeds 0.1, the overall magnetostriction will increase and the coercive force (HC) will also increase, which is not preferable.

M (T i , V , Or , M n , N
i, Y.

Z r , N b , M o , Hf , T
one or more of a, W, Rg rare earth metals)
is involved in the thermal stability of the alloy, and its composition ratio y is 0 and y
It is set within a range of 0.2. When y exceeds 0.2,
It becomes difficult to make it amorphous. Note that when M is NL, if y exceeds 0.1, the saturation magnetization becomes extremely small, making it impractical.

Generally, it is known that an amorphous alloy can be obtained by rapidly cooling an alloy material having a predetermined composition ratio from a melting state at a cooling rate of 105° C./second or more (liquid quenching method). The amorphous alloy of the present invention can also be easily produced by the conventional method described above.

The amorphous alloy of the present invention is used, for example, as a plate-like thin body produced by the conventional single-hole method. It is practically difficult, and if the thickness exceeds 25μ7π, the coercive force in high IM waves increases, so usually,
It is preferable to set the thickness of the thin body in the range of 10 to 25 μm (including both ends).

(Example of the invention) The present invention will be explained below based on examples.

(0'0.92F'f1.06Nb0.02)75(S
A thin body of an amorphous alloy consisting of 0.5110.5)2fi was produced by a single roll method. The width of each thin body is approximately p and the thickness is 1
It was in the range of 8 to 22 μm.

Cut the first length from this thin body and make a diameter of 20 rrr.
A toroidal core was prepared by winding it around a bobbin of size M. Next, this was heat-treated at an appropriate temperature below the crystallization temperature (T-11-) and above the cure temperature ('pc), and then the whole was put into water (25° C.) and rapidly cooled.

The primary and secondary windings are loosened on the obtained core, and an external magnetic field of 10
The AC hysteresis curve was measured using an AC magnetization measurement device under e, and from this the coercive force 1-I, ? and squareness ratio Br
/Bl (Br: residual magnetic flux density, B: magnetic flux density in a magnetic field of 10 g) was determined. 20KHz, 50
KHz, H of each thin body at high frequency of 100KHz
The values of C and BT/Bl are shown in Table 1. For comparison, the conventionally used sender delta values are also shown.

Margins below 7-18 = As is clear from the table, the amorphous alloy of the present invention has its Hc
is 0. 40g or less and Br/B, 85
It was large, more than %. On the other hand, Senderta is B
Although r/BI is large, HC is also large, and it becomes unmeasurable under an external magnetic field of 10 e especially at high frequencies of 50 KHz or higher, making it unsuitable as a magnetic core material at high frequencies.

Then (000.92F'0.06N'0.02)75(
Coercive force (HC) and squareness ratio (B T /B
The aging characteristics of 1) at 130°C were investigated. The results are shown in FIG. As is clear from FIG. 1, the material of the present invention has excellent thermal stability. Note that H c (t) and Bτ/B 1 (t
) is He (t) − Hc (0)
Tenα lOg. . t.

By/B1(t)=-By/f3+(0)-βl 6
It is expressed as F 1 0 t, and α and β are considered as measures of temperature stability.

It is desirable that both α and β be smaller 1 In the case of the above composition, α = 0.02 for aging at 130°C
5. β=0.005.

Table 2 shows α and βθ values of various compositions of the present invention. Also,
(0('0.90F'0.06NbO,04)77(S
The dependence of α and β on α during 130°C aging of '1ZHI-(Z)23 was investigated. The results are shown in FIG.

The following margin composition is (Ooo, 5aFso, osN'o, o4N'o
, o2)ysBtz, SL+2. A thin body of amorphous alloy with a thickness of about 16 μm was made using S, and the outer diameter was 18 m and the inner diameter was 12 mm.
A toroidal core with a thickness of 5 mm was prepared. This is 430
After heat treatment at ℃ (10500℃, T, r380℃),
It was poured into water and rapidly cooled.

The obtained core was used as a saturable reactor at 12V, 4
A switching power supply was manufactured.

After conducting a 1000H aging test at 120°C, the core temperature ('C) at full load was investigated.

For comparison, (Coo, 88F'Q, 06N'
The results using 0.04NhG, Q2) 75S t 1681s are also shown.

As is clear from Table 3, in the saturable reactor made of the amorphous alloy of the present invention, the change in temperature rise of the core after 1000 hours was much smaller than the initial value.

As is clear from the above explanation, the amorphous alloy of the present invention is
It has a small coercive force of 0.40 g or less at high frequencies, a large squareness ratio of 85% or more, and excellent thermal stability, making it useful for magnetic cores such as magnetic amplifiers, and its industrial value. is extremely large.

[Brief explanation of the drawing]

Figure 1 shows (0'o, zF'o, oaN'o, oz) 7s
(Sjo, 5Bo5) 2s is a diagram showing the aging characteristics of coercive force (HC) and squareness ratio (BT/Bt) at 130° C. at 50KH2. Figure 2 is (0'o9oF”o, oaNbo, o4)yy
(SLaB+-7Z) 23 is a diagram showing the α dependence of α and β in 130°C aging 1,

Claims (1)

[Claims] +! 1 (0°1-x-y F'x My) too-
zc8'a B+-a) zM=Ti, V, Or, Mn,
Ni, Y, Zr, Nh. Consists of one or more rare earth metals such as MO, Hf, Ta, W rare earth metals 0<x<0.1 0.005<9<0.2 20kuzku30 0.4.0<:α<;:0.55 An amorphous alloy with high thermal stability, low coercive force, and high square shape. Claim 1 in which +2+15x<:25
High thermal stability, low coercive force, high angularity amorphous alloy as described in Section 1. The high thermal stability, low coercive force, high angularity amorphous alloy according to claim 1, wherein: +31 0.45 <α<;: 0.53. +41 (00+ -x-y P'x My)1oo
-z(S'aB+-12)ZM=Ti, V, Or, Mn
, Ni, Y, Zr, Nh. Mo, Hf, Ta, W rare earth metals 018 or more +1<-T<0.1 0.005<31<0.2 20kuzku30 0.40<α<0.55 A toroidal saturable reactor made of a stable, low coercivity, high angular amorphous alloy. (5) The saturable reactor according to claim 4, in which an amorphous alloy ribbon is wound to form a toroidal shape.