JPS61174364A - Permanent magnet - Google Patents

Abstract

PURPOSE:To develop a rare earth element-Fe-B permanent magnet excellent in the magnetic characteristics in the extremely low cost by using essentially La and Ce as the rare earth element in the rare earth element-Fe-B permanent magnet. CONSTITUTION:An ingot having the composition shown in the general formulas (I) and (II) is manufactured by a smelting method. In the formulas (I) and (II), R is at least one kind of rare earth metal other than Ce and La (contg. Y) and M is at least one kind of Al, Ti, V, Cr, Mn, Zr, Hf, Nb, Ta, Mo, Ge, Sb, Sn, Bi, Ni, W, Cu and Ag and the suffixes are shown as follows. 0.4<=x<=0.9, 0.2<y<=1.0, 0.05<=z<=0.3, 0.01<=v<=0.3, 0<=u<=0.2, 0<w<=0.5. The permanent magnet is manufactured by crushing this ingot into small pieces, making them ribbonlike by a liquid quenching method due to a single roll method, crushing them and bonding them with a binder such as resin.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to rare earth-iron permanent magnets.

[Conventional technology]

BACKGROUND ART Research has been actively conducted in recent years on permanent magnets containing rare earth elements -Fe-B as a basic component, and the results are beginning to be published in published patent publications and the like.

According to JP-A-57-141901, a composition consisting of a combination of a transition group metal (T), a metalloid metal (M), Y, and a lanthanide element R is made amorphous, and then the amorphous composition is crystallized by heat treatment. A method for manufacturing permanent magnet powder is described in which coercive force is generated by oxidation. According to this publication, T is Ti.

V, Cr, Mn, Fe, Co, N
i, Cu, Zr, Nb, Mo, H
f.

One or a combination of two or more selected from Ta and W, M is one or a combination of two or more selected from B, Si, P, and C, and R is one selected from Y and a lanthanide element. or a combination of two or more types,
These are expressed by the relational expression (T+-, MX) and R1-2 (where 0≦x
A patent is claimed for a permanent magnet powder containing powder with a content of 0.35, 0.35, z, and 0.90.

According to JP-A-58-123853, a material containing La and Pr has been proposed, and its composition is (Fe,
B+-x)y (Lag Prw B+-z-w)
+-y, where R is a rare earth metal other than La or Pr, x
=0.75-0.85, y =0.85-0.95, Z
=0.40-0.75, W=0.25-0.60, z
+w: 51.0. In this publication, in order to appropriately increase the coercive force when annealing and crystallizing an R-Fe-B-containing alloy that has been made amorphous by a liquid quenching method, it is stated that the type and proportion of rare earth elements are adjusted as described above ( Lag Prw B+-g
-w) is described.

JP-A-59-46008 discloses that 8 to 30 atom % of R (wherein R is at least one kind of rare earth element), 2 to 2
A magnetically anisotropic sintered body consisting of 8 at % B and the balance Fe has been proposed. One of the intentions of the invention disclosed in this publication is to make it possible to manufacture a permanent magnet body of any shape by a sintering method rather than by a liquid quenching method. Also,
Regarding R in the sintered body components, Nd alone, Pr alone, N
Combinations of d and Pr, combinations of Nd and Ce, combinations of Sm and Pr, combinations of Pr and Y, combinations of Nd, Pr and La, Tb alone, Dy alone, Ho alone, Er and Tb, etc. The magnetic properties of the solid body are shown.

To summarize the prior art as mentioned above, R-Fe-B (however,
R is a rare earth metal, the same applies hereafter) system permanent magnet, R is N
It can be seen that excellent magnetic properties were obtained when the magnet was d or Pr.

In addition, some prior art patents claim that La and Ce can be used as rare earth elements, but instead of using only La as R,
By limiting the upper limit of the content of La, deterioration of magnetic properties due to a large amount of La is avoided. In the above-mentioned prior art, there is no example of a permanent magnet specifically composed of rare earth components mainly composed of La and Ce.

Figure 2 shows J, Appl, Phys, Vo155 (19
84) This is the demagnetization curve of the R-Fe-B permanent magnet alloy at both temperatures as shown in the graph published in No. 2079. From this graph, it can be seen that Pr and Nd are the most desirable R components of R-Fe-B alloys, and alloys with La or Ce as R components of R-Pe-B alloys no longer have the characteristics as permanent magnets. I understand. From this point of view, even though the above-mentioned prior art discloses replacing a very small portion of Pr, Nd, etc. with La or Ce, the R component is mainly composed of 1, a, or Ce. It can be said that there is no disclosure that the R-Fe-B alloy made into a permanent magnet.

Recent notable developments in rare earth-iron permanent magnets include:
Fe-(32,
5-34.5%) R-(1-1.6%) B, (where R is didymium (Nd-10%Pr), 5Ce-didymium, or 4O-Ce didymium) i Hc = 10.2K G ,
(B H) , , , = 40 MGOe was achieved. (rDIDYMIUM-Fe-B SIN
TERt! D PIERMANENTAHA GNETS
To J Theory). However, even in this permanent magnet, the R component is mainly Nd.

[Problem that the invention seeks to solve]

Permanent magnets whose basic components are R-Fe-B have excellent magnetic properties, but one problem with them is that in order to obtain excellent magnetic properties, Nd and Pr must be used as the main rare earth metals. This made permanent magnets expensive. Therefore, the didymium-containing permanent magnet is attracting attention because it can exhibit magnetic properties equivalent to those of Nd and Pr even when relatively inexpensive didymium is used.

La or Ce is produced in large quantities and is inexpensive compared to other rare earth elements, so if it were possible to use them as the main components of rare earth metals, it would be possible to significantly reduce the cost of rare earth-iron permanent magnets. . However, as can be seen from FIG. 2, La and Ce are elements harmful to magnetic properties. L
The reason why Ce is harmful in terms of magnetic properties is that the ferromagnetic components of rare earth-iron permanent magnets are R, Fe, B compounds,
When R is La, the compound becomes unstable or is not produced, and when R is Ce, R (Ce) z
This is because Fel 4B has a small coercive force.

As mentioned above, the prior art has not reached the point where La and Ce are used as main components of rare earth metals.

[Means for solving problems]

Figure 1 shows a plate manufactured using the liquid quenching method with a thickness of 20 μm and a width of 3.
Dragon's Feww (t, a+-x Cex) I? It is a graph showing the results of measuring the coercive force of B4 alloy.

In the composition formula Fet@(La+-x Cew)+Js, the coercive forces when x=1 (i.e., Fe7tCe+Ji) and x=0 (i.e., PettLa+Jb) almost match the data for Ce and La, respectively, in Figure 2. .

Note that the slight difference is due to the difference in the composition of the alloys whose coercive forces are shown in both figures.

As shown in FIG. 1, when both La and Ce are used as rare earth elements, the coercive force is much higher than when either La or Ce is used alone. X value is approximately 0.65
Therefore, the coercive force (iHc) is approximately 7 kOe. This coercive force is about 172 times the coercive force of a permanent magnet whose R is mainly Pr or Nd, but La.

If it becomes possible to construct the R component only from Ce, etc., such permanent magnets will be sufficiently cost-effective compared to permanent magnets mainly composed of Pr and Nd.
They will be able to compete in terms of overall performance.

The present invention (hereinafter referred to as the first invention) is as shown in FIG.
It is based on the invention that the coercive force (i Hc ) is significantly increased by the coexistence of Ce, tLa + - *
)g CFer-vBv )+-g, however, 0.4 ≦
x≦0.9.0.05≦z≦0.3.0.01≦V≦0
．． It has a composition of 3 and a coercive force (iHc) of 4 kOe or more.

The ratio of heavy rare earth elements in R is desirably 0.4 or less, particularly 0.2 or less. In the present invention, X is less than 0.4 or 0
．． If it exceeds 9, a coercive force equivalent to that of La alone or Ce alone cannot be obtained, so X = 0.4
~0.9. Moreover, if 2 is less than 0.05, the squareness ratio and coercive force will decrease, and if Z exceeds 0.3, the residual magnetic flux density will decrease, so Z=0.05 to 0.3. Furthermore, if ■ is less than o or oi, the coercive force will decrease,
Further, since the residual magnetic flux density decreases when V exceeds 0.3, V was set to 0.01 to 0.3.

Furthermore, in order to obtain a higher coercive force, 0.6≦x≦
0.8.0.02≦V≦0.15.0.1≦z≦0.
A range of 2 is preferable. More preferably 0.
03≦V≦0.12.

The reason why the coercive force (i, Hc) is set to 4 kOe or more in the present invention is that when a coercive force of 4 kOe is achieved, a remarkable synergistic effect between Ce and La is recognized.
Fe-B-(
This is because La, Ce) type magnets have characteristics that are popular in the market and can be substituted for various permanent magnets. The first point is
As is clear from the figure, regarding the latter point, La uses an inexpensive element called Re-B and is produced in large quantities among rare earth metals.

The permanent magnet of the present invention, which uses Ce and has a coercive force of 4KOe or more, is a rare earth cobalt-based and Fe-B-P
r (Nd) type and ferrite type permanent magnet, so from these points, 4kO
e and above are the constituent requirements of the present invention.

FIG. 3 and FIG. 4 respectively show FetsM+sB+
.

This is a graph showing the coercive force (iHc) of an alloy having the composition formula FetaM+tB5 made into a thin ribbon by the liquid quenching method by changing the circumferential speed (V) of a single roll. show). In addition, M in the above composition formula is approximately 32
%La, about 48%Ce, about 15%Nd, about 4.5%P
It is a Mitsushi metal consisting of about 0.3% Sm and the balance Fe and other impurities.

As can be seen from FIGS. 3 and 4, the coercive force reaches its maximum of about 8 kOe when the peripheral speed (V) of the single roll is about 30 m/s.

Furthermore, the coercive force obtained after aging the ribbon obtained under cooling conditions at a circumferential speed of a single roll that achieves the maximum coercive force at 550°C and 600°C is also shown in Figures 3 and 4 with zero aging data. From above, FetsM+sB+.

As mentioned above with reference to Figures 3 and 4, it can be seen that alloys with compositions Fe, sM+, and Bs have a low coercive force (iHc) in a liquid quenched state, but increase in coercive force by aging (11L Even when a small amount of rare earth elements other than a and Ce are present, there is a synergistic effect of La and Ce, (
2) It can be seen that such a synergistic effect is dependent on processes such as liquid quenching and aging treatment and is caused by the chair composition.

The present invention (hereinafter referred to as the second invention) is based on such a discovery, and its characteristics are as follows: )
z(Fe+-vBv)+-g, where R is at least one rare earth metal (including Y), 0.4≦x≦0.9
．． 0.2 < y <1.0.0.05≦z≦0.3
, o, ot≦V≦0.03, and R is Ce and La
a composition of at least one rare earth element other than 4k
It has a coercive force (iHc) of Oe or more.

The reasons for limiting x, z, and v in the second invention and their preferred ranges are the same as in the first invention. Furthermore, in the second invention, y is set to exceed 0.2 (y>0.2) because La
This is because if the amount of CaO is 0.20 or less, the cost of the rare earth element becomes high. Also, the reason for setting y<1.0 is that the first
This is to distinguish the compositions of the invention and the second invention. The preferred range of y is 0.5≦y<1.0.

The alloys according to the first invention and the second invention include ^l.

Ti, V, Cr, Mn, Zr, I
f, Nb, Ta, Mo, Ge, S
b.

Elements such as Sn, Bi, Ni, W, Cu, and Ag can be added. These elements have the effect of further improving coercive force. The amount to be added is 0≦u≦0.2 since the residual magnetic flux density decreases when U exceeds 0.2.

Considering high coercive force and high energy product, preferably 0.
001≦u≦0.1, more preferably 0.002≦u
≦0.05.

Furthermore, a part of B of the first invention and the second invention is replaced with Si, C.
,Aj! , P, N, Ge, S, etc., B substituted with Si etc. has the same effect as B alone.

In addition, when CO is added to the alloys according to the first and second inventions, the Curie temperature increases and the magnetic properties, especially B
The temperature characteristics of r are improved. The amount added is W in the claim.
If it exceeds 0.5, the characteristics as an inexpensive magnet will be diminished and the coercive force will decrease, so Q<w≦0.5. Preferably 0.001≦W≦0.35.

[For production]

As mentioned above, a remarkable feature of the permanent magnet according to the present invention is that it is less expensive in terms of composition than conventional permanent magnets.

That is, the feature of the present invention is to produce an extremely inexpensive permanent magnet mainly using La and Ce, which were conventionally considered to be unusable as components of Fe-BR permanent magnets. Therefore, in the present invention, the coercive force is maximum when the atomic ratio of La and Ce is about 0.35 to about 0.65, and the coercive force (iHc) is about 35 times, about 3.5 times compared to Ce alone
It will be doubled. In order to investigate the cause of the remarkable increase in coercive force (iHc) due to the coexistence of La and Ce, the present inventors investigated the Fevs (La+-*Ce, )+
The crystal structure of tBs was examined using X-rays, and the existence of R1Fe1a B-type crystals was confirmed. This crystal had the same crystal form as that conventionally detected in Nd-Fe-B alloys.

Conventionally, it has been thought that La does not form R1Fe1a B-type crystals, and therefore La
It was not used as a main component. However, in the composition of the present invention in which La and Ce coexist, R2Pe14B
Since the existence of type crystals was confirmed, it was found that when La and Ce coexist, R, Fe, and B type crystals are generated. Therefore, it is considered that this crystal contributes to the improvement of coercive force (iHc).

In addition, CetFela B has a lattice constant a, = 0.877
A tetragonal crystal is made, and its coercive force (iHc) is La −
It is known that it is much higher than Fe-B. However, according to the present invention, by coexisting Ce and La, a much higher coercive force (i
Hc) is obtained. Considering this point, the high coercive force (i Hc) obtained by the present invention is due to the fact that La and Ce are R
It is thought that there is also a contribution due to the presence of zFez B in a certain proportion in the crystal.

It has not been elucidated how such La and Ce affect the crystal structure. Elucidation of its crystallographic mechanism will have to wait for future research.

Examples of permanent magnets of the present invention manufactured by a liquid quenching method using a single roll will be described below.

In addition to the liquid quenching method, the permanent magnet according to the present invention can be produced by
It can be manufactured by a liquid quenching temporary effect method and a sintering method. Regarding these methods, the liquid quenching temporary effect method is a method to increase the coercive force (iHc) by heat treatment, and the sintering method is a method that increases the coercive force (iHc) by heat treatment, and the sintering method is a method that increases the coercive force (iHc) by sintering powder of a predetermined composition at 900 to 1150°C. This is a method of manufacturing permanent magnets.

Generally speaking, the method for manufacturing magnet materials using the sintering method of the present invention is as follows. First, raw materials are mixed to a desired composition. This is heated in an inert gas such as argon or in a vacuum. After melting and casting, an ingot of the alloy is obtained. In this case, the blended composition or the once melted ingot may be melted and a ribbon may be formed using a liquid quenching method.

Next, the obtained ingot or ribbon is subjected to solution treatment or aging and pulverization as required. The pulverization is carried out in accordance with a known coarse pulverization or fine pulverization method to obtain a magnetic alloy powder of 2 to 15 μm. Thereafter, compression molding is performed without a magnetic field or in a magnetic field of about 3 to 15 kOe.

Next, the molded body is heated to 900 to 1
After sintering at 200°C for 0.5 to 6 hours, it is cooled. Next, if necessary, aging treatment is performed at 350 to 950°C for 0.2 to 60 hours. As for the aging treatment, a higher coercive force can be obtained by using a multi-stage aging treatment in which aging is performed on the low temperature side after the first stage aging on the high temperature side. In this way, the magnet material of the present invention is manufactured.

Furthermore, the powder bonding method is a method in which the ribbon or powder obtained by the liquid quenching method is further subjected to aging treatment and pulverization if necessary, and then bonded with a resin or the like to form a bonded magnet.

Further, the details of the method for manufacturing the bonded magnet material will be described below.

First, raw materials are blended to give the desired composition. This is melted in an inert gas such as argon or in vacuum to obtain an alloy ingot. Next, the obtained ingot is crushed into small pieces and made into a ribbon shape or a quenched powder by a liquid quenching method. The ribbon or powder is subjected to optimal heat treatment as necessary, or the ingot is heated to 900-1150°C.
．． After holding for 5 to 30 hours, cool. After this, the ingots are subjected to optimal heat treatment at a temperature range of 950-350° C. for 0.2-60 hours with various profiles. In this case, the heat treatment is preferably performed under an inert gas or vacuum. The bulk body prepared as described above is crushed. The pulverization follows a known coarse pulverization or fine pulverization method. 5-30
A magnetic alloy powder of 0μ is obtained. This powder is subjected to surface treatment if necessary. Next, this magnet alloy powder and a binder are mixed in a predetermined ratio. The binder may be a resin, a metal binder, or the like, and the binder may be impregnated after molding. Next, orientation and compression molding are performed in a magnetic field of about 3 to 10 kOe, and sufficient solidification is performed after compression molding. In this case, orientation in the magnetic field and compression molding may be performed simultaneously in one step, and further pressure As for the molding, injection molding may be performed in addition to normal pressure molding.

In addition, during orientation, compression molding, and solidification, the compression force, solidification time, temperature, etc. at that time may be the same as those for known bonded magnets.

The present invention will be explained in detail below.

[Example 1] An ingot whose composition is shown in Table 1 was produced by a melting method,
The ingot was broken into small pieces, and ribbon-shaped samples were produced by liquid quenching using a single roll and varying the surface speed of the roll. The following table shows the coercive force of the sample obtained at the surface speed of the roll where the coercive force (iHc) is maximum.

Margin Example 2 Below, an ingot whose composition is shown in Table 2 is manufactured by a melting method, the ingot is crushed into small pieces, and the ingot is made into a ribbon-like sample by a liquid quenching method using a single roll by changing the surface speed of the roll. was manufactured. Next, the sample obtained was ground at the surface speed of the roll that maximized the coercive force (iHc) to obtain powder for a magnet alloy. The thus obtained powder was mixed with a surface-treated binder at a weight ratio of 1:Q, 02 to 0.4, compression molded in a magnetic field of 10 kOe, and then solidified. The best properties obtained are shown in Table 2.

Margin Example 3 Raw materials were prepared to have the composition shown in Table 3, and this mixture was melted by high frequency heating in an argon atmosphere to obtain a magnetic alloy ingot having the above composition. 3 to 1 of these ingots
Finely pulverized to 0 μm, molded in a magnetic field of about 10 kOe,
After sintering in a vacuum at 50 to 1150°C for about 2 hours, it was cooled.

Next, aging treatment was performed at 950 to 350°C. Next, this sintered body was crushed to a size of 10 to 200 μm to obtain a magnet alloy powder.

This powder was subjected to strain relief annealing as necessary. After surface treatment, the powder thus obtained was mixed with the binder in a weight ratio of 1
:0.02 to 0.4 and molded in a magnetic field of 10 kOe. The highest values obtained are shown in Table 3.

The following margin [Effects of the invention] The permanent magnet according to the present invention is extremely inexpensive and has a coercive force (
iHc) is expected to be used in various applications since it has a satisfactorily high value.

[Brief explanation of drawings]

Figure 1 shows Fett (La+-x Ce, )l? B&
A graph showing the relationship between the X value and coercive force (i Hc).
, ois) 0.1165 demagnetizing field curve, Figures 3 and 4 are FetsM+sB+. and pe
Peripheral speed (V) and coercive force (
It is a graph showing the relationship of iHc). Drawing modification M (change to Ft'1 size) Figure 1 Figure 2 Figure 3 Figure 4 Procedural amendment (voluntary) July 1985

Claims (1)

[Claims] 1, [Ce_xLa_1_-_xR_1_-_y]z[
(Fe_1_-_uMu)_1_-_vB_v〕_1_
-_2- However, R is Ce, at least one rare earth metal other than La (including Y), and M is Al, Ti, V, C
r, Mn, Zr, Hf, Nb, Ta, Mo, Ge, Sb
, at least one element from the group consisting of Sn, Bi, Ni, W, Cu and Ag, 0.4≦x≦0.9, 0.2<y≦1.0, 0.05≦
z≦0.3, 0.01≦V≦0.3, 0≦u≦0.2-
A permanent magnet material made by mixing magnet alloy powder with the following composition with a binder. 2, [(Ce_xLa_1_-_x)_yR_1_-_
y]z[(Fe_1_-_u_-Co_wMu)_1_
-_vB_v]_1_--However, R is Ce, at least one rare earth metal other than La (including Y), and M is A
l, Ti, V, Cr, Mn, Zr, Hf, Nb, Ta,
At least one element from the group consisting of Mo, Ge, Sb, Sn, Bi, Ni, W, Cu and Ag, 0.4≦x≦0.9, 0.2<y≦1.0, 0.05 ≦
z≦0.3, 0.01≦V≦0.3, 0≦u≦0.2,
A permanent magnet material made by mixing a magnet alloy powder having a composition of 0<W≦0.5- with a binder.