JPH04272104A - Manufacture of ferrous soft magnetic alloy green compact and ferrous soft magnetic alloy powder - Google Patents

Abstract

PURPOSE:To permit the manufacture of a magnetic product combining high saturation magnetic flux density and high megnatic permeability and provided with high mechanical properties and heat stability and thus to easily obtain a megnetic product of high performance even with a complicated shape in a magnetic head core, a transformer, a choke coil or the like. CONSTITUTION:This is high saturation megnetic flux density ferrous alloy powder and ferrous soft magnetic alloy powder having a compsn. shown by the following formulas 1, 2, 3 and 4, i.e., (formula 1):(Fe1-a Coa)b BX Ty T'z (formula 2): Fe b Bx Ty T'z, (formula 3):(Fe1-a Coa)b Bx Ty and (formula 4): Fe b Bx Ty; where in the above each formula, T denotes one or >= two kinds of elements selected from a group constituted of Ti, Zr, Hf, V, Nb, Ta, Mo and W and furthermore contains either Zr or Hf or both, and T<1> denotes one or >= two kinds of elements selected from a group constituted of Cu, Ag, Au, Ni, Pd and Pt as well as, by atomic%, a<=0.05, b<=92, x=0.5 to 16, y=4 to 10 amd z<=4.5 are satisfied.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a Fe-based soft magnetic alloy compact and a method for producing the Fe-based soft magnetic alloy powder used for manufacturing magnetic heads, transformers, choke coils, etc.

0002

2. Description of the Related Art The following properties are generally required for soft magnetic alloys used in magnetic heads, transformers, choke coils, etc.

[0003] ■ High saturation magnetic flux density. ■High magnetic permeability. ■Have low coercive force. ■It is easy to obtain a thin shape.

[0004] Also, for magnetic heads, the above
In addition to the properties described above, the following properties are required from the viewpoint of wear resistance.

■High hardness.

[0006] Therefore, when manufacturing soft magnetic alloys or magnetic heads, material research is being conducted on various alloy systems from these viewpoints.

Conventionally, crystalline alloys such as sendust, permalloy, and silicon steel have been used for the above-mentioned applications, and recently, Fe-based and Co-based amorphous alloys have also been used. There is.

[0008]

However, in the case of magnetic heads, a more suitable magnetic material for high-performance magnetic heads is desired in order to cope with the increase in coercive force of magnetic recording media accompanying the increase in recording density. Further, in the case of transformers and choke coils, as electronic devices become smaller, further miniaturization is required, and therefore, magnetic materials with higher performance are desired.

However, although Sendust has excellent soft magnetic properties, it has the disadvantage of a low saturation magnetic flux density of about 11 KG, and permalloy similarly has an alloy composition with excellent soft magnetic properties that has a saturation magnetic flux density of about 11 KG. It has the disadvantage of being as low as 8KG, and although silicon steel has a high saturation magnetic flux density, it has the disadvantage of poor soft magnetic properties.

On the other hand, among amorphous alloys, Co-based alloys have excellent soft magnetic properties, but have an insufficient saturation magnetic flux density of about 10 KG. Further, although Fe-based alloys have a high saturation magnetic flux density of 15 KG or more, they have insufficient soft magnetic properties. Furthermore, the thermal stability of amorphous alloys is not sufficient, and there are still unresolved issues.

As mentioned above, it is difficult to have both high saturation magnetic flux density and excellent soft magnetic properties.

By the way, the above-mentioned amorphous alloy is usually obtained in the form of a thin strip by a rapid cooling method, and the thin strip is punched out or laminated to manufacture the magnetic core of a magnetic head. Choke coils and the like that have complicated shapes may not be manufactured from the amorphous alloy ribbon. In such cases, a method is used in which magnetic heads and choke coils are obtained by producing amorphous alloy powder and compacting it together with a binder to form a green compact.

However, since conventional amorphous alloys have the above-mentioned problems, it is obvious that powdered amorphous alloys also have the above-mentioned problems.

[0014] Therefore, the present inventors previously proposed a high saturation magnetic flux density Fe-based soft magnetic alloy, which solved the problems of the conventional alloys and amorphous alloys, in Japanese Patent Application No. 108308/1990 in 1990. A patent application was filed on April 24th.

Another alloy related to this patent application was a high saturation magnetic flux density alloy characterized by having a composition represented by the following formula.

(Fe1-a Co a)b Bx Ty
T'z

[0017] However, T is Ti, Zr, Hf, V, N
One or two selected from the group consisting of b, Ta, Mo, and W
is an element or more, and contains either or both of Zr and Hf, and T' is Cu, Ag, Au, Ni, Pd, P
One or more elements selected from the group consisting of t, a≦0.05, b≦92 atomic%, x=0.5 to 16
% by atom, y=4 to 10 atomic%, and z=4.5 atomic% or less.

[0018] Another alloy according to the patent application is a high saturation magnetic flux density alloy characterized by having a composition represented by the following formula.

[0019]Fe b Bx Ty T’z

0020
] However, T is Ti, Zr, Hf, V, Nb, Ta, Mo,
It is one or more elements selected from the group consisting of W, and contains either or both of Zr and Hf, and T'
is one or more elements selected from the group consisting of Cu, Ag, Au, Ni, Pd, and Pt, and b≦
92 atom %, x = 0.5 to 16 atom %, y = 4 to 10 atom %, and z = 4.5 atom % or less.

Furthermore, the present inventors have previously filed a patent application for an alloy having the composition shown below as an advanced alloy of the above-mentioned alloy.

One of the alloys related to this patent application was a high saturation magnetic flux density alloy characterized by having a composition represented by the following formula.

(Fea Co a) b Bx Ty

0
[024] However, T is Ti, Zr, Hf, V, Nb, Ta,
One or more elements selected from the group consisting of Mo and W, and contains either or both of Zr and Hf, a≦0.05, b≦92 atomic%, x=0 .5-16
% by atom, and y=4 to 10 atomic%.

[0025] Another alloy according to the patent application is a high saturation magnetic flux density alloy characterized by having a composition represented by the following formula.

[0026]Fe b Bx Ty

[0027] However, T is Ti, Zr, Hf, V, Nb, T
is one or more elements selected from the group consisting of a, Mo, and W, and contains either or both of Zr and Hf, b≦92 atomic %, x = 0.5 to 16 Atomic %, y
=4 to 10 at%.

As described above, the present inventors have developed various Fe-based soft magnetic alloys having the above-mentioned compositions, and as a result of repeated research on the alloys having the above-mentioned compositions, it has been found that these alloys can be made into powder without any problem. It has been found that magnetic properties can be obtained, and the present invention has been achieved.

The present invention has been made to solve the above problems, and provides a soft magnetic alloy compact and a soft magnetic alloy that have both high saturation magnetic flux density and high magnetic permeability, as well as high mechanical properties and high thermal stability. The purpose of the present invention is to provide a method for producing powder.

[0030]

[Means for Solving the Problems] In order to solve the above problems, the invention as set forth in claim 1 is made by consolidating a high saturation magnetic flux density Fe-based soft magnetic alloy powder having a composition represented by the following formula. be.

(Fe1-a Co a)b Bx Ty
T'z

[0032] However, T is Ti, Zr, Hf, V, N
One or two selected from the group consisting of b, Ta, Mo, and W
is an element or more, and contains either or both of Zr and Hf, and T' is Cu, Ag, Au, Ni, Pd, P
One or more elements selected from the group consisting of t, a≦0.05, b≦92 atomic%, x=0.5 to 16
% by atom, y=4 to 10 atomic%, and z=4.5 atomic% or less.

In order to solve the above-mentioned problem, the invention as set forth in claim 2 is obtained by consolidating a high saturation magnetic flux density Fe-based soft magnetic alloy powder having a composition represented by the following formula.

[0034]Fe b Bx Ty T’z

0035
] However, T is Ti, Zr, Hf, V, Nb, Ta, Mo,
is one or more elements selected from the group consisting of W, and contains either or both of Zr and Hf;
' is one or more elements selected from the group consisting of Cu, Ag, Au, Ni, Pd, and Pt, b≦92 atomic%, x=0.5 to 16 atomic%, y=4 ~10 atomic%,
z=4.5 atomic % or less.

In order to solve the above-mentioned problem, the invention as set forth in claim 3 is obtained by consolidating a high saturation magnetic flux density Fe-based soft magnetic alloy powder having a composition represented by the following formula.

(Fe1-a Co a)b Bx Ty

[0038] However, T is Ti, Zr, Hf, V, Nb, T
is one or more elements selected from the group consisting of a, Mo, and W, and contains either or both of Zr and Hf, a≦0.05, b≦92 atomic %, x =0.5～
16 atom%, y=4 to 10 atom%.

In order to solve the above-mentioned problem, the invention as set forth in claim 4 is obtained by consolidating a high saturation magnetic flux density Fe-based soft magnetic alloy powder having a composition represented by the following formula.

(Fe1-a Co a)b Bx Ty

[0041] However, T is Ti, Zr, Hf, V, Nb, T
is one or more elements selected from the group consisting of a, Mo, and W, and contains either or both of Zr and Hf, a≦0.05, b≦92 atomic %, x =0.5~
16 atom%, y=4 to 10 atom%.

[0042] In order to solve the above-mentioned problem, the invention described in claim 5, when producing the high saturation magnetic flux density Fe-based soft magnetic alloy powder according to claim 1, 2, 3, or 4, The high saturation magnetic flux density Fe-based soft magnetic alloy having the composition described in , 2, 3 or 4 is heated to a temperature equal to or higher than the crystallization temperature to make it brittle and then pulverized.

[0043]

[Action] Since the compact is formed using soft magnetic alloy powder with a specific composition, it has both high saturation magnetic flux density and high magnetic permeability.
Moreover, it is possible to obtain a green compact of a Fe-based soft magnetic alloy that has both high mechanical properties and thermal stability.

[0044] Furthermore, it has been found through research by the present inventors that the soft magnetic alloy having the above-mentioned specific composition becomes brittle when heated above the crystallization temperature. can do.

The present invention will be explained in more detail below.

In order to obtain the high saturation magnetic flux density Fe-based soft magnetic alloy powder according to the present invention, a molten metal of a soft magnetic alloy having the composition for which the present inventors have previously applied for a patent is rapidly cooled by an atomization method or the like to form a powder. It can usually be obtained by a step of oxidation and a heat treatment step of heating the product obtained in the above step to precipitate fine crystal grains. In addition, when producing the above-mentioned soft magnetic alloy powder, the alloy for which the present inventors have applied for a patent is first produced, and this alloy is heated to a temperature higher than the crystallization temperature to make it brittle, and then pulverized. You can also do it.

For example, in order to obtain a magnetic alloy powder by the atomization method, an alloy material having the above composition is made into a molten metal in a crucible using a high-frequency melting furnace, and the molten metal is passed through a nozzle for spouting the molten metal provided at the bottom of the crucible. to flow down, to fall. It can be obtained by spraying nitrogen gas at a predetermined pressure onto the molten metal stream falling from the spouting nozzle using, for example, a circularly arranged multi-hole atomization nozzle to pulverize the molten metal stream.

[0048] Furthermore, the inventors' research has revealed that the Fe-based soft magnetic alloy with the above composition becomes brittle when heated above the crystallization temperature, so this property can be used to make it into powder. You can also do that. It is also possible to pulverize an alloy having the above composition by heating it to a temperature above the crystallization temperature, preferably in the temperature range of 550 to 650° C. to embrittle it, and crush it in this state to make the particle size uniform.

In order to easily obtain an amorphous phase in the alloy powder of the present invention, it is necessary to contain either Zr or Hf, which has a high ability to form an amorphous phase. In addition, Zr and Hf partially contain Ti, V, Nb, Ta among other group 4A to 6A elements.
, Mo, and W. The reason why Cr was not included here is that Cr has an inferior ability to form an amorphous state compared to other elements, but if appropriate amounts of Zr and Hf have been added, Cr may also be added. Of course.

B is considered to have the effect of enhancing the amorphous formation ability of the alloy of the present invention and the effect of suppressing the formation of compound phases that adversely affect the magnetic properties in the heat treatment process, and therefore the addition of B is essential. It is. Similar to B, A1, S
i, C, P, etc. are also generally used as amorphous forming elements, and the addition of these elements can be considered to be the same as the present invention.

In the present invention, at least one or two selected from Cu, Ni, and their homologous elements
If the amount of addition of the above elements is less than 0.2 atomic %, excellent soft magnetic properties cannot be obtained by the heat treatment process, so it is preferably 0.2 atomic % or more.
Moreover, among these elements, Cu is particularly suitable.

As is clear from the graph shown in FIG. 8, the Fe-based soft magnetic alloy has a cooling rate of 1 during heat treatment.
Good magnetic permeability can be obtained at temperatures above 00°C/min.
The amount of the above elements added may be 0.2 atomic % or less.

Although the mechanism by which the soft magnetic properties are significantly improved by the addition of Cu, Ni, etc. is not clear, when the crystallization temperature was measured by differential thermal analysis, it was found that the addition of Cu, Ni, etc.
The crystallization temperature of alloys to which Ni and the like were added was found to be slightly lower than that of alloys to which no Ni was added. This is because the amorphous phase becomes non-uniform due to the addition of the above elements, and as a result,
This is thought to be due to a decrease in the stability of the amorphous phase. Furthermore, when a non-uniform amorphous phase crystallizes, many regions where crystallization is likely to occur are formed locally, resulting in non-uniform nucleation, so that the resulting structure is considered to be a fine grain structure.

[0054] Furthermore, especially in the case of Cu, which is an element with extremely low solid solubility in Fe, there is a tendency for phase separation, so heating causes microscopic fluctuations in composition, and the tendency for the amorphous phase to become non-uniform becomes more pronounced. It is thought that this contributes to the refinement of the structure.

From the above point of view, Cu and its homologous elements, N
Similar effects can be expected for elements other than i, Pd, and Pt that lower the crystallization temperature. Further, similar effects can be expected with elements such as Cu, which have a small solid solubility limit with respect to Fe.

The reasons for limiting the alloying elements contained in the high saturation magnetic flux density Fe-based soft magnetic alloy of the present invention have been explained above, but in order to improve corrosion resistance with elements other than these, Cr, R
u It is also possible to add other platinum group elements, and if necessary, Y, rare earth elements, Zn, Cd, Ga
, In, Ge, Sn, Pb, As, Sb, Bi, Se,
Magnetostriction can also be adjusted by adding elements such as Te, Li, Be, Mg, Ca, Sr, and Ba. others,
Regarding unavoidable impurities such as H, N, O, and S, even if they are contained to the extent that the desired characteristics are not deteriorated, the composition can be considered to be the same as the composition of the high saturation magnetic flux density Fe-based soft magnetic alloy of the present invention. Of course.

The amount b of Fe and Co in the alloy of the present invention is:
It is 92 atomic % or less. This is because, as will be explained later, high magnetic permeability cannot be obtained if b exceeds 92 at.%, but in order to obtain a saturation magnetic flux density of 10 kG or more, it is better for b to be at least 75 at.%. preferable.

Next, the results of actually manufacturing an alloy having the above composition and measuring the magnetic properties of the obtained soft magnetic alloy will be shown.

The alloys shown in the following examples were prepared by the single roll liquid quenching method. That is, from a nozzle placed on one rotating steel roll, molten metal is jetted onto the roll under the pressure of argon gas, and is rapidly cooled to obtain a ribbon. The width of the ribbon produced as described above was about 15 mm, and the thickness was about 20 to 40 μm.

Magnetic permeability was determined by processing a thin ribbon, with an outer diameter of 10 mm,
A ring shape with an inner diameter of 5 mm was formed, and the rings were stacked and wound, and measured by the inductance method. This permeability (
The measurement conditions for μ) were 10 mOe and 1 KHz.

First, the effect of heat treatment on the magnetic properties and structure of the alloy of the present invention will be explained below using Fe86Zr7B6Cu1 alloy, which is one of the alloys of the present invention, as an example. The crystallization start temperature of the Fe86Zr7B6Cu1 alloy was determined to be 503°C by differential thermal analysis at a heating rate of 10°C per minute.

FIG. 1 shows the effect of sintering (water quenching after holding at each temperature for 1 hour) on the effective magnetic permeability of Fe86Zr7B6Cu1 alloy.

As shown in FIG. 1, the effective magnetic permeability of this alloy in the rapidly cooled state (RQ) is as low as that of Fe-based amorphous alloys, but by annealing at 500 to 620°C, it becomes about 10 times higher than in the rapidly cooled state. The value has increased. Here, we investigated the frequency dependence of magnetic permeability for a sample with a thickness of approximately 20 μm after heat treatment at 600°C, and found that it was 32,000 at 1 KHz and 25 at 10 KHz.
It showed excellent soft magnetic properties even at high measurement frequencies, such as 600 KHz and 8330 KHz at 100 KHz. In addition, when we investigated the effect of cooling rate on magnetic permeability, we found that at 600℃
The effective magnetic permeability of this alloy is 32,000 when quenched by water quenching after holding for a time, but when air-cooled, the value is 1,800.
The cooling rate after heat treatment is also important;
It is preferable to perform rapid cooling at a cooling rate of 1/min or more.

Therefore, the magnetic properties of the present alloy can be adjusted by appropriately selecting the optimum heat treatment conditions, and the magnetic properties can also be improved by annealing in a magnetic field.

Furthermore, changes in the structure of the Fe86Zr7B6Cu1 alloy before and after heat treatment were investigated by X-ray diffraction, and the structure after heat treatment was observed using a transmission electron microscope. The results are shown in FIGS. 2 and 3, respectively.

From FIG. 2, a halo diffraction pattern characteristic of amorphous crystals is observed in the rapidly cooled state, and a diffraction pattern unique to body-centered cubic crystals is observed after heat treatment. It can be seen that the crystal has changed from a body-centered cubic crystal to a body-centered cubic crystal. FIG. 3 shows that the structure after heat treatment consists of microcrystals with a grain size of about 100 angstroms. In addition, when we investigated the change in hardness of Fe86Zr7B6Cu1 alloy before and after heat treatment, we found that the Vickers hardness ranged from 740DPN in the rapidly cooled state to 1390DPN after heat treatment at 650℃.
It was also found that the material increased N to a high value not found in conventional materials, making it suitable for use as a material for magnetic heads.

As described above, the alloy having the above composition is produced by crystallizing the amorphous alloy having the above composition by heat treatment to obtain a structure consisting mainly of ultrafine crystal grains, and thereby exhibiting high saturation magnetic flux density and soft magnetic properties. It is possible to obtain excellent properties such as high hardness and high thermal stability.

Next, the case where the alloy obtained as described above is powdered will be explained.

The above-mentioned alloy becomes an amorphous phase structure in a rapidly cooled state, so it is highly ductile, and it is difficult to crush it into powder in that state. Therefore, the alloy obtained as described above is heated to 500° C. or higher to make it brittle and then pulverized using a pulverizing device such as a ball mill or an attritor. By this operation, a soft magnetic alloy powder with a particle size of about 1 to 100 μm can be obtained.

Next, the case of manufacturing a magnetic head core using this soft magnetic alloy powder will be explained.

First, as shown in FIG. 4, soft magnetic alloy powder A is primarily formed into a core B having a predetermined shape by the upper die PU and lower die PL of the press device P. This primary molded core B is then placed in a pressure medium powder C in a pressurized capsule 10 shown in FIG.
It will be enclosed with. In the drawing, only one maintenance molding core B is depicted, but in reality, a large number of primary molding cores B are enclosed within the pressurized capsule 10 at the same time.

The pressurized capsule 10 has a cylindrical body 11 with a bottom.
and a lid 12 that covers the top of the main body 11,
A deaeration pipe 13 is opened in the lid body 12. Inside the pressurized capsule 10, the primary molded core B and the pressure medium powder C are filled into the main body 11 with the lid 12 removed. Next, the upper inner surface of the main body 11 is covered with a mesh plate 14 through which the primary forming core B and the pressure medium powder C do not pass, and the main body 11 and the lid 12 are welded to eliminate the gap between the main body 11 and the lid 12. Then, the degassing pipe 13 is crushed to complete a sealed workpiece 30 (pressure capsule 10) in which the primary molded core B and the pressure medium powder C are sealed.

[0073] When degassing, the pressurized capsule 10 is placed in a heating furnace F, and a baking temperature of about 500°C to 900°C is applied. This is heating to make degassing more complete, and is customary in this type of degassing.

Pressure medium powder C is soft magnetic alloy powder A (
Select and use materials that do not chemically react with the primary molded core B). Here, since the primary molded core B is a Fe-based soft magnetic alloy powder having the above composition, it is preferable to use ZrO2 powder. In addition, MgO powder may be used.

FIG. 6 is a conceptual diagram of the hot isostatic press 20 that processes the workpiece 30 under high temperature and high pressure.The upper and lower parts of the high-pressure cylinder 21 can be opened, closed, and closed by a lid 23 with an upper lid 22. There is. A high-pressure gas introduction pipe 24 is opened in the upper lid 22 . A support stand 25 for the workpiece 30 and a heater 26 are located inside the high-pressure cylinder 21 , and a heat insulating layer 27 is provided between the high-pressure cylinder 21 and the heater 26 .

The workpiece 30 is placed on the support stand 25 of this hot isostatic press, heated to a high temperature by the heater 26, and at the same time is isostatically heated by the high pressure gas as a pressure medium introduced from the introduction pipe 24. Under sexual pressure. As a result, the entire workpiece 30 (capsule 10) is compressed and deformed. During this compression deformation process, the primary molded core B within the pressurized capsule 10 is subjected to isostatic pressure via the pressure medium powder C. Further, since the heat from the heater 26 is also received via the pressure medium powder C, the primary molded core B is not heated rapidly, and the primary molded core B due to sudden heating is not heated.
No cracking or deformation occurs. That is, the primary molded core B is uniformly compressed, internal air bubbles are removed, and finally sintered to complete the magnetic head core D. Since this magnetic head core D shrinks compared to the primary molded core B, the shape of the primary molded core B is determined in consideration of the shrinkage margin.

Workpiece 3 compressed and deformed as described above
0 is taken out from the hot isostatic press, its main body 11 and lid 12 are broken as shown in FIG. 7, and the completed magnetic head core D inside is taken out. Since the magnetic head core D has been previously processed into a predetermined shape by the press device P, it can be used as a magnetic head core as it is.

[0078] Furthermore, in the above hot isostatic press,
Since the primary molded core B is covered with the pressure medium powder C which does not chemically react with the primary molded core B, there is no fear that the properties of the completed magnetic head core D will change.

In the above explanation, the case of manufacturing the magnetic head core D has been explained, but by appropriately changing the shape of the mold of the press device P, it is possible to manufacture not only magnetic head cores but also transformers, electric motors, and choke coils. It goes without saying that this method can be widely used as a method for manufacturing magnetic cores such as magnetic cores.

Next, a magnetic head core was manufactured by the method described above with reference to FIGS. 4 to 7, and the magnetic performance of this magnetic head core was measured.

[0081] As the Fe-based soft magnetic alloy powder, F90Zr
An alloy obtained by heating and pulverizing an alloy having a composition of 7B2Cu1 above the crystallization temperature was used.

[0082] This soft magnetic alloy powder was primarily formed into the shape of a magnetic head core using a press machine. Next, this primary molded product was subjected to preliminary sintering at 500 to 600°C in an inert gas atmosphere including vacuum. Next, this primary molded product was sintered at a temperature of 600°C, a pressure of 5000 atm, and a time of 1.
Hot isostatic pressing was carried out at a certain time.

The magnetic permeability μe(1
KHz) was 18,000, coercive force was 0.03 Oe, and saturation magnetic flux density was 16.7 kG, confirming that it exhibited excellent magnetic properties.

[0084]

[Effects of the Invention] As explained above, the present invention consolidates soft magnetic alloy powder with a specific composition, so it has both high saturation magnetic flux density and high magnetic permeability, and has excellent mechanical properties and thermal stability. It is effective in manufacturing magnetic products. Therefore, in magnetic head cores, transformers, choke coils, etc.
This has the effect of making it possible to easily obtain high-performance magnetic products even if the shape is complex.

In addition, if the soft magnetic alloy with the specific composition becomes brittle at temperatures above the crystallization temperature and is crushed into powder, it will have both high saturation magnetic flux density and high magnetic permeability, and will have high mechanical properties. This has the effect of making it possible to easily obtain a soft magnetic alloy powder that can be used to manufacture magnetic products made of green compacts with excellent thermal stability.

[Brief explanation of the drawing]

FIG. 1 is a graph showing the relationship between magnetic permeability and heat treatment temperature of an example of a Fe-based soft magnetic alloy.

FIG. 2 is a graph showing an X-ray diffraction pattern showing structural changes of the alloy before and after heat treatment.

FIG. 3 is a schematic diagram of a micrograph showing the structure of the alloy after heat treatment.

FIG. 4 is a schematic diagram showing how a primary molded core is formed from soft magnetic alloy powder using a press device.

FIG. 5 (A) to (C) in FIG. 5 are cross-sectional views showing how the primary molded core is placed in a pressurized capsule.

FIG. 6 is a conceptual diagram of a hot isostatic press that presses the pressurized capsule of FIG. 5 at high temperature.

FIG. 7 is a schematic diagram showing a state in which the magnetic head core is taken out from inside the pressurized capsule.

FIG. 8 is a graph showing the relationship between cooling rate and magnetic permeability during heat treatment of a Fe-based soft magnetic alloy.

[Explanation of symbols]

A Soft magnetic alloy powder B Primary molded core C Pressure medium powder D Magnetic head core 10 Pressure capsule 11 Main body 12 Lid body 13 Deaeration pipe 20 Hot isostatic press 21 High pressure cylinder 24 High pressure gas introduction pipe 26 Heater 30 Work (pressure capsule)

Claims (5)

[Claims] 1. An Fe-based soft magnetic alloy green compact, characterized in that it is made by compacting a high saturation magnetic flux density Fe-based soft magnetic alloy powder having a composition represented by the following formula. (Fe1-a Co a) b Bx Ty T'z where T is one or more elements selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Mo, and W, and , Zr, Hf, or both, and T' is C
One or more elements selected from the group consisting of u, Ag, Au, Ni, Pd, and Pt, a≦0.05, b≦92 atomic%, x=0.5-1
6 atom%, y=4 to 10 atom%, and z=4.5 atom% or less. 2. An Fe-based soft magnetic alloy green compact, characterized in that it is made by compacting a high saturation magnetic flux density Fe-based soft magnetic alloy powder having a composition represented by the following formula. Fe b Bx Ty T'z However, T is Ti, Zr, Hf, V, Nb, Ta, Mo, W
is one or more elements selected from the group consisting of, and contains either or both of Zr and Hf, and T' is selected from the group consisting of Cu, Ag, Au, Ni, Pd, and Pt. b≦92 at%, x=0.5 to 16 at%, y
=4 to 10 at%, z=4.5 at% or less. 3. An Fe-based soft magnetic alloy green compact, characterized in that it is made by compacting a high saturation magnetic flux density Fe-based soft magnetic alloy powder having a composition represented by the following formula. (Fe1-a Co a) b Bx Ty where T is Ti
, Zr, Hf, V, Nb, Ta, Mo, and W, and Zr
, Hf, or both, a≦0.05, b≦92 atomic%, x=0.5~
16 atom%, y=4 to 10 atom%. 4. An Fe-based soft magnetic alloy green compact, characterized in that it is made by compacting a high saturation magnetic flux density Fe-based soft magnetic alloy powder having a composition represented by the following formula. Fe b Bx Ty where T is Ti, Zr, Hf, V, Nb, Ta, Mo, W
one or more elements selected from the group consisting of, and contains either or both of Zr and Hf, b≦92 at%, x=0.5 to 16 at%, y
=4 to 10 at%. 5. When producing the high saturation magnetic flux density Fe-based soft magnetic alloy powder according to claim 1, 2, 3 or 4, highly saturated powder having the composition according to claim 1, 2, 3 or 4 is used. A method for producing a Fe-based soft magnetic alloy powder, which comprises heating a magnetic flux density Fe-based soft magnetic alloy to a temperature equal to or higher than its crystallization temperature to embrittle it and then pulverizing it.