JPH08296006A - Alloy magnetic material with excellent coercive force and residual magnetization,its preparation and its use - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a magnetic alloy having an excellent coercive force, residual magnetization as well as superior in economy by converting it to be amoprphous and heat-treating an alloy having a specific ingredient composition.

SOLUTION: A small amount of a soft magnetic phase of RE₂-Fe₁₄B or RE₂(Fe, CO)₁₄B is precipitated on a soft magnetic base of α-Fe or α(Fe, CO), the low-RE base phase of Re-Fe-B magnet is transformed, thereby producing an α-Fe base RE-Fe-B ultra-fine grain magnetic alloy. Thus alloy has a principal phase of the soft magnetic phase having a body-centered cubic system structure with a small amount of the soft magnetic phase having a tetragonal structure added thereto and a composition represented by formula: RE_xFe_yCO_zB_uM_vCu_w. This ultra-fine grain magnetic alloy is converted to be amorphous and heat- treated thereby producing a magnetic alloy that has an excellent coercive force and residual magnetization and is highly economical. In the formula, x is ≤5 at.%, y is ≤90 at.%, z is ≤25 at.%, u is ≤15 at.%, v is ≤5 at.%, and w is ≤5 at.%.

COPYRIGHT: (C)1996,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a high remanence (B
The present invention relates to a rare earth magnetic material having r = 1.2T), a method for producing the same, and its use. RE in this specification
(Rare Earth) represents a rare earth element, and C
e, Pr, Nd, Sm, Eu, Gd, Tb, Dy, A
It means one or a combination of two or more of o, Er, Tm, Yb, Lu and Y. Further, M is N which is a high melting point element.
It represents b, Mo, V, W, or Ta, and means any one or a combination of two or more of them.

[0002]

2. Description of the Related Art In the case of high performance rare earth magnetic materials, it has been pointed out that the economical efficiency and the chemical stability are poor due to the high content of rare earth elements. Therefore, recently, the development of the RE-Fe-B magnetic material with the RE content reduced to 5 at% or less has been actively promoted. The low rare earth element-containing RE-Fe-B magnetic material that has been developed up to now, as disclosed in Korean Laid-Open Patent Publication No. 94-700735, has a small amount in the Fe ₃ B matrix (matrix) that is a metastable magnetic phase. RE ₂
It is an ultrafine-bonded alloy in which F ₁₄ B is precipitated and exhibits a high remanence (Br = 1.2T), and has the potential of application to high-energy isotropic permanent magnets, magnetic recording media, and broadband ultrahigh-frequency absorption. presentation.

[0003]

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

[0004]

DISCLOSURE OF THE INVENTION The present invention is a RE containing low RE
-Fe-B alloy magnetic material, 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 group RE-Fe-B ultrafine grain alloy magnetic material in which a light 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 RE-Fe-B alloy having a low RE exhibits high remanence is due to magnetic interaction between the soft magnetic phase and the light magnetic phase. As a method for obtaining a higher residual magnetization from such an alloy,
It is necessary to increase the magnetization of the soft magnetic phase. Therefore, the present inventors have come to contemplate the invention of an RE-Fe-B ultrafine crystalline alloy containing α-Fe having a larger magnetization than Fe ₃ B as a main phase.

The object of the present invention is to provide conventional low RE RE-Fe.
Α-Fe group RE-Fe with improved magnetic properties by changing the matrix phase of -B magnet
-B To provide an ultrafine crystal grain alloy magnetic material and a method for manufacturing the same.

The α-Fe-based RE-Fe-B ultrafine 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 a light magnetic phase having a tetragonal structure in a small amount. With the added alloy, RE _x Fe _y Co _z B _u M _v Cu _w
It has a composition of. Where M is a refractory element such as Nb or M
One or more elements 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,
Represents w = 5 at% or less. And the soft magnetic phase is α-Fe
Alternatively, it is α- (Fe, Co) in which a part thereof is replaced with Co, and the light magnetic phase is RE ₂ Fe ₁₄ B or RE ₂ (Fe,
Co) ₁₄ B is preferred.

In the method for producing an α-Fe-based RE-Fe-B ultrafine grain alloy magnetic material according to the present invention, RE (rare earth element), Fe, Co, B, M (high melting point element) and Cu are specified. At a temperature of 500 ° C. after the amorphous alloy is produced by the rapid solidification method in the non-oxidizing atmosphere from the molten alloy containing
The heat treatment is performed at ˜800 ° C. This makes α-F
α- (Fe, Co) in which e or a part thereof is replaced with Co
Soft magnetic matrix phase and a small amount of RE ₂ Fe ₁₄ B or RE ₂
An ultrafine grain magnetic alloy having a light magnetic phase of (Fe, Co) ₁₄ B can be obtained. Hereinafter, the content 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 RE-Fe-B alloy composition having a low RE content is reduced to 20 at% or less so that RE ₂ Fe ₁₄ B can be precipitated in the matrix phase of e.
An alloy was experimentally produced, and an amorphous phase was produced from the molten metal by the rapid solidification method. Then, the sample was obtained by heat treatment, and the phase change and the magnetic property were investigated.

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

In order to improve such results, a small amount of Cu, which is considered to increase the α-Fe nucleation rate at the initial stage of crystallization because the solid solubility in Fe is very low, is added to the crystal grains. Low RE RE-Fe-BM-Cu (M is Mo, Nb, V, W or Ta) added with Mo, Nb, V, W and Ta which are high melting point elements judged to suppress growth. Among them, any one or two or more of them was designed and modified into an amorphous phase by utilizing the rapid solidification method (or mechanical alloy method).

As a result, although the coercive force (iHc) among the magnetic properties of the RE-Fe-BM-Cu alloy was improved, the squareness ratio (Br / B) of the hysteresis loop in the magnetic hysteresis curve was obtained.
s) was low and the residual magnetization (Br) was not improved. Therefore, in order to improve it, in order to further refine the crystal grains and improve the magnetization of the soft magnetic phase, α-Fe is added to Co / Fe = 1.
Low RE content RE- (Fe, C
o) -BM-Cu (M = Mo, Nb, V, W, Ta)
After designing an alloy and producing a non-oxidizing amorphous phase from the molten metal using a rapid solidification method or a mechanical alloying method, heat treating at 500 to 800 ° C. to produce a sample,
The magnetic property investigation and phase analysis of this were systematically performed.

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 been precipitated, and it was also confirmed that the addition of Co increased the remanent magnetization without decreasing the 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 content of boron is further reduced, the residual magnetization rises and the maximum magnetic energy product [(BH) m
ax] significantly increases, and exhibits magnetic properties superior to existing Fe ₃ B-based RE-Fe-B alloys in the vicinity of a boron content of 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, and a small amount of a light magnetic phase having a tetragonal crystal structure is generated therein. In addition, as a result of earnest research, RE _x Fe _y Co _z B _u M _v Cu _w (where M is N
In the composition of one or more refractory elements of b, Mo, V, W, and 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 are preferable, and the soft magnetic phase thereof is α-Fe or α- (F
e, Co), the light magnetic phase is RE ₂ Fe ₁₄ B or RE
It has been clarified that the one having ₂ (Fe, Co) ₁₄ B is preferable. The alloy according to the present invention can be used for manufacturing a magnetic recording medium by vapor-depositing or sputtering the alloy. 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-F was used so that Nd was used as a rare earth element and Nd ₂ Fe ₁₄ B was precipitated in the matrix phase of α-Fe.
A 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 rapidly solidified by a single roll in a non-oxidizing atmosphere. After manufacturing the amorphous alloy, it was heat-treated at 600 ° C. to prepare Comparative Sample 1.

(Comparative Example 2) The Nd content in Comparative Example 1 was maintained, and the B content was lowered to 10.5 at%.
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 content was kept as it was, the content of B was set to 10 at%, Cu was added to it at 1 at%, and Mo, Nb or V which is a high melting point element was added at 3 at%, respectively, and the production conditions were the same as those of 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, part of Fe is Co and Co / Fe are 1 / 19.5 (Example 1), 1 / 9.25 (Example 2), 1 / The composition was Nd ₄ (Fe, Co) ₈₂ B ₁₀ Mo ₃ Cu ₁ by substituting to 5.83 (Example 3) and 1 / 4.13 (Example 4), 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) Example samples 5 and 6 were prepared in the same manner as in example 2 except that the refractory element was replaced with Mo from Nb and V respectively.

(Examples 7 and 8) The contents of B, Mo and Cu in Example 2 were changed to the contents of Nd and Co to some extent, and the production conditions were the same as those of Example 2 to obtain Samples 7 and 8. Sample 8 was prepared.

(Examples 9 to 11) N in Example 5
The content of b and Cu is left unchanged, and the content of B is 6 at
%, The contents of Nd and Co were changed to some extent, and the manufacturing conditions were the same as those in Example 2 to prepare Samples 9 to 11 of Examples.

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

As a result of Comparative Examples 1 and 2, as a result of X-ray diffraction analysis, in the case of Comparative Example 1 having a high B content, the main phase was F.
e ₃ B, and the magnetic characteristics are not improved. In the case of Comparative Example 2 in which the content of B is low, the main phase is α-Fe and Nd ₂
Although it represents a fine structure in which Fe ₁₄ B is formed in a small amount, the crystal grains are coarse and the magnetic characteristics (B ₂ = 1.21
T, iHc = 1.2 KOe) was low. Comparative Example 3
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 to 4, α- (Fe, Co)
An alloy in which Nd ₂ (Fe, Co) ₁₄ B was precipitated in the matrix phase was obtained, and the addition of Co had the effect of increasing the residual magnetization without decreasing the coercive force. The results of Examples 5 and 6 show that the high remanent magnetization of 1.2 or more and the 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, good alloy magnetic materials having a remanent magnetization of 1.2 or more and a squareness ratio of 0.65 or more were obtained. In Examples 9 to 11, the residual magnetization was further improved, and the maximum magnetic energy product [(BH) ma
An alloy magnetic material having excellent magnetic properties in which x] greatly increases was obtained.

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

FIG. 1 shows the influence of the content of rare earth elements,
2 shows the effect of adding B and Co based on Comparative Example 2, FIG. 3 shows the effect of adding refractory element (V) and B and Co based on Comparative Example 2, and FIG. The influence of the addition of the high melting point element (Mo) and B and Co is shown.

FIG. 5 shows the influence on the magnetic characteristics due to the change in the composition ratio of Fe and Co when the contents of other components are constant, and FIG. 6 shows that the contents of other components are constant. When
It shows the influence on the magnetic characteristics by the 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%) in the same manner as in Example 2 after amorphization by the rapid solidification method, and then only the heat treatment temperature is 620 ° C.
To 700 ° C., the magnetic alloy of the present invention was prepared, and its magnetic characteristic values were graphed and shown in FIG. 7.

[0031]

[Table 1]

[0032]

As described above, the α-Fe group R according to the present invention is used.
E-Fe-B ultrafine crystal grains magnetic alloy magnetic properties and thermal and chemical stability is improved compared to existing Fe ₃ B group low RE-containing magnets. In addition, the 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 electromagnetic wave absorbers. It is a useful material for. Also, the magnetic alloy of the present invention can of course be mixed with a rubber or plastic material to make a permanent magnet.

Although the present invention has been described in detail only with respect to the specific examples described above, it will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the technical idea of the present invention. Of course, such variations and modifications are, of course, within the scope of the appended claims.

[Brief description of drawings]

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

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

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

FIG. 4 Component composition of magnetic alloy (especially 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 the magnetic alloy (particularly the composition ratio of Fe and Co) and the magnetic characteristics.

FIG. 6 is a component composition of a magnetic alloy (especially rare earth element and F
3 is a graph showing the relationship between the magnetic properties 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 characteristics of the magnetic alloy according to the present invention.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Motoi Kanazawa 152 Doure Apartment 102, No. 1006, 152, Shinseong-dong, Yuseong-gu, Daejeon, South Korea

Claims (9)

[Claims] 1. A rare earth alloy magnetic material having a structure in which a soft magnetic phase having a cubic body-centered cubic lattice structure is a main phase and a small amount of a light magnetic phase having a tetragonal structure is added. , RE _x Fe _y Co _z B _u M _v Cu _w ,
In the above, RE (Rare Earth) is the rare earth element Ce, P
r, Nd, Sm, Eu, Gd, Tb, Dy, Ao, E
r, Tm, Yb, Lu, Y represents one or a combination of two or more, and M is a high melting point element Nb, M
one or more elements of any one 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
% And w = 5 ta% or less, an ultrafine grain alloy magnetic material excellent in coercive force and remanence. 2. The soft magnetic phase is α-Fe or α- (Fe, Co) in which a part of Fe is replaced by Co, and the light magnetic phase is RE ₂ Fe ₁₄ B or RE ₂ (Fe, Co). ) ₁₄ B
The alloy magnetic material according to claim 1, wherein 3. The substitution ratio of Fe and Co is Co / Fe =
The alloy magnetic material according to claim 2, which is 1/4 or less. 4. A component composition of RE _x Fe _y Co _z B _u M _v Cu _w (RE is a rare earth element Ce, Pr, Nd, Sm, E.
u, Gd, Tb, Dy, Ao, Er, Tm, Yb, L
Either u or Y, M is a refractory element Nb, M
of any one of o, V, W or Ta), an amorphous alloy is manufactured by a rapid solidification method in a non-oxidizing atmosphere and then heat-treated at 500 to 800 ° C., Method for producing ultrafine grain alloy magnetic material having a soft magnetic phase as a main phase and a light magnetic phase having a tetragonal structure with a small amount of added structure and excellent coercive force and remanence 5. The soft magnetic phase is α-Fe or α- (Fe, Co) in which a part of Fe is replaced with Co, and the light magnetic phase is RE ₂ Fe ₁₄ B or RE ₂ (Fe, Co). ₁₄ B
5. The method for producing an alloy magnetic material according to claim 4, wherein 6. The substitution ratio of Fe and Co is Co / Fe =
The method for producing an alloy magnetic material according to claim 5, which is ¼ or less. 7. A permanent magnet manufactured by mixing the alloy magnetic material according to claim 1 with a rubber or a plastic substance. 8. A magnetic recording medium using the alloy magnetic material according to claim 1. 9. A broadband electromagnetic wave absorber using the alloy magnetic material according to claim 1.