JPS61159709A - Permanent magnet - Google Patents

Abstract

PURPOSE:To manufacture a permanent magnet at extremely low cost by specific component constitution mainly comprising La and Ce. CONSTITUTION:A permanent magnet has a composition represented by a formu la (CexLa1-x)z[(Fe1-uMu)1-vBv]1- z. R represents one kind of a rare earth metal (including Y) except Ce and La and M at least one kind of elements in a group consisting of Al, Ti, V, Cr, Mn, Zr, Hf, Nb, Ta, Mo, Ge, Sb, Sn, Bi, Ni, W, Cu and Ag in the formula. 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 hold, and the magnet has coercive force (iHc) of 4kOe or more.

Description

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

[Conventional technology]

In recent years, research has been actively conducted on permanent magnets containing rare earth elements -F and -B as basic components, 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 (ii), a metalloid metal (ii), 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 a coercive force is generated by the following steps. According to this publication, T is TI, V, Or, Mn
, F@, Co, Nl, Cu, Zr
.

One or a combination of two or more selected from Nb, Mo, Hf, Ts, W, and M is B.
, 81.

One type or combination of two or more types selected from P and C, R
is one or two selected from Y and the lanthanide elements
A combination of more than one species, which is (T1-xMx
)zRl-z (however, 0≦x≦0.35.0
．． A patent is claimed for a permanent magnet powder containing a powder with a content of 35≦2≦0.90).

According to JP-A-58-123853, a material containing L& and Pr has been proposed, and its composition is <F@
, s 1 ++ x ) y < La Kp rwn
1-z-W) 1-y, where R is La,
Rare earth metal other than Pr, x=0.75-0.85, y=
0.85-0.95, small=0.40-0.75, w=0
．． 25-0.60. z+w≦1.0. This publication describes the type and proportion of rare earth elements in order to appropriately increase the coercive force when annealing and crystallizing the R-F@-B-containing alloy that has been made amorphous by the liquid quenching method. The above (Lζ”
A method for adjusting the composition to obtain vRl-+c-v) is described.

JP-A No. 59-46008 discloses 8 to 30 atoms of R (wherein R is at least one rare earth element), 2 to 2
A magnetically anisotropic sintered body consisting of 8 atoms of B1 and the remainder F. 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 the OR in the sintered body components, Nd alone, Pr alone, N
Combination of d and Pr, combination of Nd and CI, combination of Sm and Pr, combination of Pr and Y, combination of Nd, Pr and L&, Tb alone, D7 alone, Ho alone, Er and Tb
The magnetic properties of the sintered body are shown for combinations of.

To summarize the prior art as mentioned above, R-F・-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 dt or Pr.

In addition, some prior art patents claim that La and C can be used as rare earth elements, but they do not use only La as 8 (the upper limit of La content is limited). In particular, deterioration of magnetic properties due to a large amount of La is avoided.In the above conventional technology, L
There is no example of a permanent magnet in which rare earth components are specifically composed of & and C.

Figure 2 ktJ, Appl, Phys, Vol, 5
5 (1984), page 2079, which is a reproduction of the demagnetization curve of the R-F·-B permanent magnet alloy. This graph also shows that Pr and Nd are R-F・-B
The most desirable R component of the alloy is La or C.
It can be seen that the alloy containing the R component of the -F/-B series alloy no longer has the characteristics as a permanent magnet. From this point of view, even though the above-mentioned prior art discloses replacing a very small part of Pr, Nd, etc. with La, C.
R-F・- whose R component is composed mainly of a or C・
It can be said that there is no disclosure that the B alloy becomes a permanent magnet.

Recent notable developments in rare earth-iron permanent magnets include:
F*-(32,5~
34.5S)R-(IN1.6%)B.

(However, R is didymium (Nd-10%Pr), 5Ce-didymium, or 40-C didimium) tHc = 10.2k
G 1(BI()mA! = 40 MGO* has been achieved.(r DIDYMIUM-Fkai-B 8I
NTERED PERMANENTMihGNET8
J paper). 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 RF and -B have excellent magnetic properties, but one problem with them is that in order to obtain excellent magnetic properties, Nd and Pr must be 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.

Since L& or C is produced in large quantities and is inexpensive compared to other rare earth elements, if it can be used as the main component of these rare earth metals, it will be possible to significantly reduce the cost of rare earth-iron permanent magnets. Become.

However, as can be seen from Figure 2, La and C are elements that are harmful in terms of magnetic properties. The reason why La and C are harmful in terms of magnetic properties is that the ferromagnetic component of rare earth-iron permanent magnets is R.
If it is a 2Fe, 4B compound, and R is La, the compound will become unstable or will not be produced, and R(C・) 2F・, 4B, where R is C・, has a small coercive force. It is.

As mentioned above, the prior art has not reached the point of using La and C as the main components of rare earth metals.

[Means for solving problems]

Figure 1 shows a plate with a thickness of 20 mm and a width of 3 mm manufactured using the liquid quenching method.
It is a graph showing the results of measuring the coercive force of the F.77C"1-X"X)17"4 alloy.

In the composition formula F.78(L'1-x"x)17BS, x=1 (i.e.?@1yC@, 7B6) and x
= 0 (that is, F・77"17B!), the coercive force almost matches the data for Ce and La shown in Figure 2.The slight difference is due to the coercivity of the alloys whose coercive forces are shown in both figures. Due to differences in composition.

As shown in FIG. 1, when both Lm and C. are used as rare earth elements, the coercive force is greatly increased compared to when La or C. is used alone. When the λ value is approximately 0.65, the coercive force (xHc) is approximately 7 ko·. This coercive force is about 1/1 of the coercive force of a permanent magnet mainly composed of Pr or Nd1kR! However, if the R component can be composed only of La, Co, etc., such a permanent magnet will become Pr.
, it will be able to fully compete with Nd-based permanent magnets in terms of overall cost and performance.

The present invention (hereinafter referred to as the first invention) is as shown in FIG.
It was established based on the invention that the coercive force (KHc) is significantly increased by the coexistence of CI and CI.
Fist 1-v"v)1-x 'However, 0.4≦I≦0.9.0
．． The composition has a composition of 05≦2≦0.3, 0.01≦v≦0.3, and a coercive force (tHe) of 4 kO· or more. The quantitative ratio of heavy rare earths in R is preferably 0.4 or less, especially 0.2 or less. In the present invention, if I is less than 0.4 or exceeds 0.9, the composition is equivalent to La alone or C alone, respectively. x = 0.4 to 0 because only a coercive force of about
．． It was set as 9. If t2 is less than 0.05, the squareness ratio and coercive force will decrease, and if 2 exceeds 0.3, the residual magnetic flux density will decrease, so 2 was set to 0.05 to 0.3. Furthermore, if Ma is less than 0.01, the coercive force will decrease, and if Ma exceeds 0.3, the residual magnetic flux density will decrease, so Ma = 0.
．． 01 to 0.3. Furthermore, in order to obtain a high coercive force.

0.6≦x≦0.8, 0.02≦v≦0615.0.1
It is preferable that the range is ≦2≦0.2. More preferably, 0.03≦v≦0.12.

In the present invention, the reason why the coercive force (xHc) is set to 4 kO. or more is that once the coercive force of 4 kO.
This is because a remarkable synergistic effect of 4kO
・F・-B−(La
, C.) system magnets have characteristics that allow them to be substituted for various permanent magnets on the market. The former point is clear from Figure 1, and the latter point is made by using an inexpensive element called F・-B and using La and C・, which are produced in large quantities among rare earth metals, to achieve a coercive force of 4 kO・ or more. The permanent magnet of the present invention comprises rare earth cobalt-based and F・-B
-Since it can more than compete with Pr (Nd)-based and ferrite-based permanent magnets, 4kO
-The above are the constituent requirements of the present invention.

Figures 3 and 4 respectively show F.75M15Bl
.

This is a graph showing the coercive force (sHa) of an alloy having the composition formula F. (shown as 0). In addition, M in the above compositional formula is approximately 3
2 To La, approximately 484 CI, approximately 15% Nd.

It is Mitsushi metal consisting of about 4.5% pr, about 0.3968m2, 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 kO· when the circumferential speed (b) of the single roll is about 30φ.

Furthermore, the coercivity after aging the ribbon at 550° C. and 600° C., which was obtained under cooling conditions at a circumferential speed of a single roll that achieves the maximum coercive force, is also shown in FIGS. 3 and 4. From the aging data, the above F675M15B1゜ and F・78M
An alloy with a composition of 17B5 has a coercive force (x
It can be seen that even if Hc) is low, the coercive force increases due to aging.

As mentioned above with reference to Figures 3 and 4, (1) even when a small amount of rare earth elements other than La and C are present, there is a synergistic effect of La and C;
) 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: (< c @ xLa , ++,) yn 1-y ) z
＜'・1−v”v)1−s, where R is at least 1
'm rare earth metal (including Y), 0.4≦x≦0.9.
0.2 < y (1, o, 0.05≦2≦0.3.0
．． 01≦v≦0.03, R is at least one rare earth element other than CI and La, and 4kO@
The coercive force (tea) is as follows. The reasons for limitations and preferred ranges of x, z, and ma in the second invention are the same as in the first invention. Furthermore, in the second invention, (y) 0.2) is set so that F ft exceeds 0.2, because if the amounts of La and C are less than 0.20, the cost of rare earth elements becomes high. Also, y < 1. .

The reason for this is to distinguish the compositions of the first 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 have kA.

Ti, V, Cr, Mn, Zr, i
f, Nb, T*, Mo.

G*, Sb, 8n, Bl, N%, W
, Cu, Ag, and other elements 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≦O, OS.

Furthermore, part of B of the first invention and the second invention is 81,
Even when substituted with C, kl, P, N, G., S, etc., B substituted with 81 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 of addition is 0 (v≦0.5. Preferably, 0.001≦W≦0. It is 35.

[Effect]

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 C, which were conventionally considered to be unusable as components of F.-B-B permanent magnets. Therefore, in the present invention, the coercive force is maximized when the atomic ratio of La and CI is about 0.35 to about 0.65, and this coercive force (xHa) is compared to that of La alone. It is about 35 times as much as C alone, and about 3.5 times as much as C alone. In order to investigate the cause of the remarkable increase in coercive force (the) due to the coexistence of La and C, the present inventors investigated the F・78(L′1−x”x)1
The crystal structure of 7B5 was examined using X-rays, and the existence of R2F614B type crystals was confirmed. This crystal had the same crystal form as that conventionally detected in Nd-F.-B alloys.

Conventionally, it has been thought that %La does not form R2F.14B type crystals9, and therefore La has not been used as the main R component of R-F.-B permanent magnets. However, La and C
Since the presence of R, F014B type crystals was confirmed in the composition of the present invention in which .

Therefore, it is considered that this crystal contributes to the improvement of coercive force (IHc).

Also, C*2F*, 4B has a lattice constant ao=0.877(
7) Create a tetragonal crystal whose coercive force < IHI! ) is known to be much higher than La-F'・-B. However, according to the present invention, by coexisting C. and Ll, a much higher coercive force (xHa) than that of C.2F.14' is obtained. Considering this point, the high coercive force (rHe) obtained by the present invention is Lm
It is thought that there is also a contribution due to the presence of C and C in a certain ratio in the R2F·14B crystal. L like this
It has not been elucidated what effect & and C. have on 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 of increasing the coercive force (*f(a)) by heat treatment, and the sintering method is a method of increasing the coercive force (*f(a)) by heating powder of a predetermined composition at 900-1150°C.
This is a method of manufacturing permanent magnets of any shape by sintering them.

Furthermore, the powder bonding method is a method in which a magnet is obtained by a liquid quenching method, or is bonded with a resin or the like after further aging treatment and pulverization of the bomb or powder, if necessary, to form a female or compact magnet.

The present invention will be explained in detail below.

Example 1 The input whose composition is shown in Table 1 was manufactured by a dissolution method,
The input was crushed into small pieces, which were then subjected to a liquid quenching method using a single roll, and the surface speed of the roll was varied to produce a male-shaped sample. Table 1 shows the coercive force of the sample obtained at the surface speed of the roll at which the coercive force (wHe) is maximum.

Margin Example 2 Below, In-/,) whose composition is shown in Table 2 is manufactured by a melting method, Inj',) is crushed into small pieces, and this is fluorinated by a liquid quenching method using a single roll. IJ by changing surface speed
A sample in the form of 1/2 mm was produced. Table 2 shows the coercive forces of the samples obtained at the roll surface speed at which the coercive force (*He) is maximum.

Margin Example 3 Samples (21 to 24) whose compositions are shown in Table 3 were prepared in the same manner as in Example 2, and the temperature coefficient of 8r was measured.

Table 3 shows that the addition of Co improves the temperature coefficient of Br.

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

[Brief explanation of drawings]

Figure 1 shows F・7y(Lat-xC@x)t 7Bb
A graph showing the relationship between coercive force (summer He) and coercive force (He). 75'15Bl. and F.
Peripheral speed (V) and coercive force (of the semi-cooled roll of 78M17BS)
2 is a graph showing the relationship between xHc).

Claims (1)

[Claims] 1, [Ce_xLa_1_-_xR_1_-_7]_z
[(Fe_1_-_uM_u)_1_-_vB_v]_
1_-_z-However, R is at least 1 other than Ce or La
rare earth metals (including Y), and M is Al, Ti, V
, Cr, Mn, Zr, Hf, Nb, Ta, Mo, Ge,
At least one element from the group consisting of 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 having a composition having a coercive force (iHc) of 4 kOe or more. 2, [(Ce_xLa_1_-_x)_yR_1_-_
y]_z[(Fe_1_-_u_-_wCo_wM_u
)_1_-_vB_v]_1_-_z-However, R is C
e, at least one rare earth metal other than La (including Y), and M is Al, Ti, V, Cr, Mn, Zr, H
f, Nb, Ta, Mo, Ge, Sb, Sn, Bi, Ni
, W, at least one element of the group consisting of 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 having a composition such that 0<w≦0.5 − and a coercive force (iHc) of 4 kOe or more.