JP2894976B2 - Alloy magnetic material excellent in coercive force and residual magnetization, method for producing the same, and use thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a high remanent magnetization (B
The present invention relates to a rare earth magnetic material exhibiting (r = 1.2T), a method for producing the same, and a use thereof. In this specification, RE
(Rare Earth) represents a rare earth element, and includes Ce, Pr, Nd, Sm, Eu, Gd, Tb, D
It means one or a combination of two or more of y, Ho, Er, Tm, Yb, Lu, and Y. M represents a high melting point element such as Nb, Mo, V, W or Ta;
One or a combination of two or more thereof is meant.

[0002]

2. Description of the Related Art It has been pointed out that a high-performance rare earth magnetic material has a low content of rare earth elements, resulting in poor economic efficiency and chemical stability. Therefore, recently, the development of RE-Fe-B magnetic materials in which the RE content is reduced to 5 at% or less has been actively promoted. As disclosed in Korean Patent Publication No. 94-700735, a low rare earth element-containing RE-Fe-B magnetic material developed until recently has a small amount of Fe ₃ B matrix, which is a metastable magnetic phase. Is an ultrafine bonded alloy in which RE ₂ Fe ₁₄ B is precipitated,
It exhibits high remanent magnetization (Br = 1.2T) and suggests its application to high energy isotropic permanent magnets, magnetic recording media and broadband ultra-high frequency absorption.

[0003]

However, the developed alloy is still insufficient in terms of remanent magnetization, and further improvement has been desired.

[0004]

SUMMARY OF THE INVENTION The present invention provides a low RE content RE.
-Fe-B alloy magnetic material, and more specifically, a small amount of RE ₂ Fe ₁₄ B or RE _{2 in} α-Fe or α- (Fe, Co) soft magnetic matrix phase.
The present invention relates to an α-Fe-based RE-Fe-B ultrafine crystal grain alloy magnetic material in which a hard magnetic phase of (Fe, Co) ₁₄ B is precipitated, a method for producing the same, and use thereof.

It is considered that the reason why such a low RE RE-Fe-B alloy exhibits high remanence is due to magnetic interaction between the soft magnetic phase and the hard magnetic phase. To obtain higher remanent magnetization from such alloys,
It is necessary to increase the magnetization of the soft magnetic phase. Therefore, the present inventors have come to intend to invent a RE-Fe-B ultrafine crystalline alloy having α-Fe having a larger magnetization than Fe ₃ B as a main phase.

It is an object of the present invention to provide a conventional low RE RE-Fe.
Α-Fe-based RE-Fe with improved magnetic properties and improved economy by changing the matrix phase of -B magnet
-B Ultra-fine grain alloy magnetic material and a method for producing the same.

[0007] The α-Fe-based RE-Fe-B ultrafine crystal grain alloy magnetic material according to the present invention has a soft magnetic phase having a body-centered cubic lattice structure as a main phase and scattered hard magnetic phases having a tetragonal structure. an _{alloy, RE x Fe y Co z B} u M v Cu w
Having the following composition: Here, M is a high melting point element Nb, M
one, two or more of o, V, W or Ta, x = 5 at% or less, y = 90 at% or less, z = 25
at% or less, u = 15 at% or less, v = 5 at% or less,
w = 5 at% or less. And the soft magnetic phase is α-Fe
Or α- (Fe, Co) in which a part thereof is substituted by Co, and the hard magnetic phase is RE ₂ Fe ₁₄ B or RE ₂ (Fe,
Co) ₁₄ B is preferred.

[0008] The method for producing an α-Fe-based RE-Fe-B ultrafine grain alloy magnetic material according to the present invention is characterized in that RE (rare earth element), Fe, Co, B, M (high melting point element) and Cu are specified. A non-oxidizing atmosphere is used to produce an amorphous alloy from a molten alloy containing at a rate of
Heat treatment is performed at ~ 800 ° C. This gives α-F
α- (Fe, Co) wherein e or a part thereof is substituted with Co
Soft magnetic base phase and a small amount of RE ₂ Fe ₁₄ B or RE ₂
An ultrafine grain magnetic alloy having a (Fe, Co) ₁₄ B hard magnetic phase can be obtained. Hereinafter, the contents of the present invention will be described in more detail.

Prior to completing the present invention, first, α-F
RE-Fe-B having a composition in which the B content in the conventional low RE-containing RE-Fe-B alloy composition is reduced to 20 at% or less so that RE ₂ Fe ₁₄ B can be precipitated in the base phase of e.
An alloy was experimentally manufactured, and an amorphous phase was manufactured from the molten metal by a rapid solidification method, and then a phase change and magnetic properties of a sample obtained by heat treatment were investigated.

As a result of X-ray diffraction, when the B content is high, the main phase is Fe ₃ B, but when the B content is low, the main phase is α.
-Fe, which indicates an alloy structure in which RE ₂ Fe ₁₄ B is formed in a small amount. However, the magnetic properties were low probably because of the coarse crystal grains, and the improvement was necessary.

In order to improve such a result, a small amount of Cu, which is considered to increase the α-Fe nucleation rate in the early stage of crystallization because of its very low solid solubility in Fe, is added to the crystal grains. Low RE-containing RE-Fe-B-M-Cu (M is Mo, Nb, V, W or Ta) to which Mo, Nb, V, W, and Ta, which are high-melting elements determined to suppress growth, are added. Among them, an alloy was designed and modified into an amorphous phase using a rapid solidification method (or a mechanical alloying method).

As a result, among the magnetic properties of the RE-Fe-BM-Cu alloy, the coercive force (iHc) was improved, but the squareness ratio (Br / B) of the hysteresis loop in the magnetic hysteresis curve was improved.
s) was low and the residual magnetization (Br) did not improve. In order to improve this, α-Fe is changed to Co / Fe = 1 in order to further refine the crystal grains and improve the magnetization of the soft magnetic phase.
RE-containing RE- (Fe, C
o) -BM-Cu (M = Mo, Nb, V, W, Ta)
An alloy is designed and manufactured from the melt into an amorphous phase using a rapid solidification method or a mechanical alloying method in a non-oxidizing atmosphere, and then heat-treated at 500 to 800 ° C. to prepare a sample.
The magnetic properties and phase analysis of this were systematically conducted.

As a result of analyzing the phases of the alloys of these samples,
RE ₂ (Fe, Co) ₁₄ B in α- (Fe, Co) base phase
Was confirmed to have precipitated, and it was confirmed that the addition of Co increased the residual magnetization without a decrease in coercive force. That is, the magnetic alloy of the present invention has a high residual magnetization of 1.2 T or more and a high squareness ratio (Br / Bs) of 0.65 or more.

On the other hand, when the boron content is further reduced, the residual magnetization increases and the maximum magnetic energy product [(BH) m
ax] is greatly increased, and exhibits a magnetic property superior to that of the existing Fe ₃ B-based RE-Fe-B alloy at a boron content of about 6 at%.

The alloy magnetic material of the present invention has a soft magnetic phase having a body-centered cubic lattice structure as a main phase, in which a small amount of a hard magnetic phase having a tetragonal structure is formed. And a result of intensive _{studies, RE x Fe y Co z B} u M v Cu w ( where M is N
b, Mo, V, W, Ta, and one or more high melting point elements) in the composition of x = 5 at% or less and y = 90
At% or less, z = 25 at% or less, u = 15 at% or less, v = 5 at% or less, and W = 5 at% or less. The structure of the soft magnetic phase is α-Fe or α- (F
e, Co), the hard magnetic phase is RE ₂ Fe ₁₄ B or RE
₂ (Fe, Co) ₁₄ B was found to be preferable. The alloy according to the present invention can be used for producing a magnetic recording medium by vapor deposition or sputtering. Hereinafter, specific comparative examples and examples of the present invention and the results of physical property analysis thereof will be described in detail.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION

(Comparative Example 1) Nd is used as a rare earth element, and an existing Nd-F is used so that Nd ₂ Fe ₁₄ B precipitates in the α-Fe base phase.
An Nd—Fe—B alloy having a composition of Nd ₄ Fe ₇₇ B ₁₉ in which the B content in the e—B alloy composition was reduced to 19 at% was set, and the molten metal was subjected to a rapid solidification method using a single roll under a non-oxidizing atmosphere. After manufacturing the amorphous alloy, heat treatment was performed at 600 ° C. to prepare Comparative Example Sample 1.

(Comparative Example 2) The Nd content in Comparative Example 1 was kept as it was, and the B content was reduced to 10.5 at% to reduce the Nd content.
Comparative Example Sample 2 was prepared in the same manner as Comparative Example 1 _{except that} the composition was changed to ₄ Fe _85.5 B _10.5 .

(Comparative Examples 3 to 5) Nd in Comparative Example 1
The B content was set to 10 at%, the Cu content was changed to 1 at%, and the high melting point element Mo, Nb or V was added at 3 at% each. The manufacturing conditions were the same as in Comparative Example 1. Comparative Example Sample 3, Sample 4, Sample 5
It was created.

Examples 1 to 4 N in Comparative Example 3
With the contents of d, B, Mo and Cu unchanged, a part of Fe is Co, and Co / Fe is 1 / 19.5 (Example 1), 1 / 9.25 (Example 2), 1 / Substitution was made to be 5.83 (Example 3) and 1 / 4.13 (Example 4) to obtain a composition of Nd ₄ (Fe, Co) ₈₂ B ₁₀ Mo ₃ Cu ₁ , and the manufacturing conditions were Comparative Example 1. Example samples 1 to 4 were prepared in the same manner as described above.

Examples 5 and 6 Samples 5 and 6 were prepared in the same manner as in Example 2 except that the high melting point element was changed from Mo to Nb and V, respectively, and the other component compositions and production conditions were the same as in Example 2.

(Examples 7 and 8) The contents of B, Mo, and Cu in Example 2 were slightly changed in the contents of Nd and Co, and the production conditions were the same as in Example 2 and the samples of Example 7 and 8 were used. Sample 8 was prepared.

Embodiments 9 to 11 N in Embodiment 5
The content of B is 6 at, while the content of b and Cu is not changed.
%, The contents of Nd and Co were slightly changed, and the production conditions were the same as in Example 2 to prepare Example Samples 9 to 11.

Table 1 shows the test results of the component compositions, metal structures, and magnetic properties of the samples according to Comparative Examples 1 to 5 and Examples 1 to 11 described above.

As a result of Comparative Examples 1 and 2, as a result of X-ray diffraction analysis, in Comparative Example 1 having a high B content, the main phase was F.
e ₃ B, and the magnetic properties were not improved. In the case of Comparative Example 2 in which the content of B was low, the main phase was α-Fe, and Nd ₂
Although it shows a fine structure in which a small amount of Fe ₁₄ B is formed, the crystal grains are coarse and the magnetic properties (B ₂ = 1.21)
T, iHc = 1.2 KOe). Comparative Examples 3 to
In No. 5, the coercive force (iHc) was improved to 2.1 to 2.7, but the remanence (Br) was not improved because the squareness ratio of the magnetic hysteresis curve was low.

As a result of Examples 1-4, α- (Fe, Co)
An alloy in which Nd ₂ (Fe, Co) ₁₄ B was precipitated in the base phase was obtained, and the effect of increasing the residual magnetization without decreasing the coercive force was obtained by adding Co. The results of Examples 5 and 6 show that a high remanent magnetization of 1.2 or more and a high squareness ratio of 0.65 or more (Br /
A magnetic material having Bs) can be obtained.

As a result of Examples 7 and 8, a good alloy magnetic material having a residual magnetization of 1.2 or more and a squareness of 0.65 or more was obtained. In Examples 9 to 11, the residual magnetization was further improved, and the maximum magnetic energy product [(BH) ma
x] was greatly increased, and an alloy magnetic material exhibiting excellent magnetic properties was obtained.

Next, based on the data shown in Table 1, the relationship between the composition of the magnetic alloy and the magnetic properties is shown in a graph.

FIG. 1 shows the effect of the content of the rare earth element,
FIG. 2 shows the effect of adding B and Co on the basis of Comparative Example 2, FIG. 3 shows the effect of adding the high melting point element (V) and B and Co on the basis of Comparative Example 2, and FIG. This shows the effect of the addition of the high melting point element (Mo) and B and Co.

FIG. 5 shows the effect on magnetic properties due to a change in the composition ratio of Fe and Co when the content of other components is constant, and FIG. 6 shows the case where the content of other components is constant. Sometimes,
It shows the effect on magnetic properties due to a change in the composition ratio of the rare earth element (Nd) and (Fe _0.9 Co _0.1 ).

Examples 12 to 15 Alloys having the same composition as the sample of Example 2 (Nd = 4 at%, Fe = 14 at)
%, Co = 8 at%, B = 10 at%, Mo = 3 at%
%, Cu = 1 at%) after amorphization by the rapid solidification method in the same manner as in Example 2, and then only the heat treatment temperature was 620 ° C.
The magnetic alloy of the present invention was prepared while changing the temperature from 700 ° C. to 700 ° C., and the magnetic characteristic values were graphed in FIG.

[0031]

[Table 1]

[0032]

As described above, the α-Fe group R according to the present invention
E-Fe-B ultra-fine grain magnetic alloys have improved magnetic properties and thermal and chemical stability compared to existing Fe ₃ B-based low RE content magnets. In addition, economy was improved due to the decrease in the B content.

The magnetic alloy of the present invention can be widely used not only for isotropic bonded magnets but also for high-density magnetic recording media such as hard disks, diskettes or tapes, generators, motors, and broadband ultra-high frequency radio wave absorbers. It is a useful material for Also, it is obvious that the magnetic alloy of the present invention can be mixed with a rubber or plastic substance to form a permanent magnet.

In the above, the present invention has been described in detail only with respect to the specific examples described. However, it will be apparent to those skilled in the art that various changes and modifications can be made within the technical idea of the present invention. It is natural that such changes and modifications fall within the scope of the appended claims.

[Brief description of the drawings]

FIG. 1 is a graph showing the relationship between the composition of a magnetic alloy (especially a rare earth element) and magnetic properties.

FIG. 2 is a graph showing the relationship between the composition of a magnetic alloy (particularly, B and Co) and magnetic properties.

FIG. 3 is a graph showing the relationship between the component composition of a magnetic alloy (particularly, high melting point element V) and magnetic properties.

FIG. 4 Composition of magnetic alloy (particularly high melting point element Mo)
6 is a graph showing the relationship between the magnetic properties and the magnetic properties.

FIG. 5 is a graph showing the relationship between the composition of a magnetic alloy (particularly, the composition ratio of Fe and Co) and magnetic properties.

FIG. 6 shows the composition of components of a magnetic alloy (particularly, rare earth elements and F
6 is a graph showing the relationship between the magnetic characteristics and the composition ratio of e and Co).

FIG. 7 is a graph showing the relationship between the heat treatment temperature after amorphization and the magnetic properties of the magnetic alloy according to the present invention.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Moto Kanazawa 152-do, Shinseong-dong, Yuseong-gu, Daejeon, Republic of Korea No. 102, No. 1006, Apartment No. 1006 (56) References JP-A-1-149940 (JP, A) (58) 6) Field surveyed (Int.Cl. ⁶ , DB name) C22C 38/00 303 B22D 11/06 360 C21D 6/00 H01F 1/14 C22C 38/16

Claims (7)

(57) [Claims] 1. A rare earth alloy magnetic material comprising a soft magnetic phase having a cubic body-centered cubic lattice structure as a main phase and a hard magnetic phase having a tetragonal structure dispersed therein. has a composition of _{RE x Fe y Co z B u} M v Cu w,
In the above, RE (Rare Earth) is a rare earth element Ce, P
r, Nd, Sm, Eu, Gd, Tb, Dy, Ho, E
r, Tm, Yb, Lu, or Y represents one or a combination of two or more, and M is a high melting element Nb, M
o, V, W or one or more elements of Ta, x = 5 at% or less, y = 90 at% or less,
z = 25 at% or less, u = 15 at% or less, v = 5 at%
% And w = 5 at% or less, and the soft magnetic phase is α-Fe or α-Fe in which a part of Fe is substituted with Co.
(Fe, Co), wherein the hard magnetic phase is RE ₂ Fe ₁₄ B or RE ₂ (Fe, Co) ₁₄ B, an ultrafine crystal grain alloy magnetic material excellent in coercive force and residual magnetization. 2. The substitution ratio between Fe and Co is Co / Fe =
The alloy magnetic material according to claim 1, wherein the ratio is 1/4 or less. 3. The composition of RE _x Fe _y Co _{z Bu} M _v Cu _w (RE is a rare earth element Ce, Pr, Nd, Sm, E
u, Gd, Tb, Dy, Ho, Er, Tm, Yb, L
u, Y, and M is a high melting point element Nb, M
o, V, W, or Ta) from a melt of an alloy by a rapid solidification method in a non-oxidizing atmosphere, followed by heat treatment at 500 to 800 ° C. RE ₂ Fe ₁₄ B or RE ₂ (Fe, Co) having a tetragonal structure with α- (Fe, Co) soft magnetic phase in which α-Fe or Fe is partially substituted with Co as a main phase ₁₄
A method for producing an ultrafine grained alloy magnetic material having excellent coercive force and remanent magnetization exhibiting a structure in which a hard magnetic phase B is scattered. 4. The method according to claim 1, wherein the substitution ratio between Fe and Co is Co / Fe =
The method for producing an alloy magnetic material according to claim 3, wherein the ratio is 1/4 or less. 5. A permanent magnet produced by mixing the alloy magnetic material according to claim 1 with a rubber or plastic substance. 6. A magnetic recording medium using the alloy magnetic material according to claim 1 or 2. 7. A broadband radio wave absorber using the alloy magnetic material according to claim 1 or 2.