JPH03170643A - Alloy for permanent magnet - Google Patents

Abstract

PURPOSE:To manufacture the permanent magnet in which the amt. of expensive Co to be used is reduced and having excellent magnetic characteristics at low cost by subjecting the powder of an alloy obtd. by mixing specified rare earth elements, B and Fe in specified ratios and melting the mixture to orientating, compacting and sintering in a magnetic field. CONSTITUTION:An Fe-rare earth-B series alloy contg., by atom%, 12.5 to 20.0% lanthanoide series rare earth elements (in which the amt. of one or more kinds among Dy, Tb, Gd, Ho, Er, Tm and Yb is regulated to 0.05 to 5% and the balance one or more kinds of Nd and Pr, or the total amt. of Nd and Pr is regulated to >=80% and the balance at least one kind among the rare earth elements including Y except the above Dy to Yb), 4 to 20% B and the balance Fe in which a part is substituted by Co by <=35% for the total compsn. as well as, as the elements to be added, contg. specified amounts of at least one kind among Ti, Zr, Hf, Cr, Mn, Ni, Ta, Ge, Sn, Sb, Bi, Mo, Nb, Al, V and W is refined, is cooled to pulverize and is thereafter orientated, compacted and sintered in a magnetic field. The permanent magnet in which the amt. of expensive Co to be used is reduced and having excellent magnetic characteristics can be obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rare earth/iron-based high-performance permanent magnet material that does not use a large amount of cobalt, which is expensive and a scarce resource.

Permanent magnet materials are used in everything from various household electrical appliances to automobile and communication device parts to peripheral terminals for large computers. It is one of the extremely important electrical and electronic materials used in a wide range of fields. With the recent demand for higher performance and smaller size of electrical and electronic equipment, permanent magnet materials are also required to have higher performance.

Current typical permanent magnet materials are alnico, hard ferrite, and rare earth cobalt magnets.

With the recent instability of the raw material situation for cobalt, the demand for alnico magnets containing 20 to 30 tons of cobalt has decreased, and cheap hard ferrite, whose main component is iron oxide, is now becoming the mainstream magnet material. became. On the other hand, rare earth cobalt magnets are high-performance magnets with a maximum energy product of 20 MGOe or more, but they also contain 50 to 65% by weight of cobalt, and SII, which is not contained in rare earth ores,
It is very expensive because it uses a large amount of l. However, because their magnetic properties are much higher than that of other magnets, they have come to be used mainly in small, high-value-added magnetic circuits.

In order for high-performance magnets such as rare earth cobalt magnets to be used in large quantities and at low cost in a wide range of fields, it is necessary to
It is necessary that the material does not contain expensive cobalt and contains light rare earth elements such as neodymium and praseodymium, which are contained in large amounts in ores, as rare earth metals.

Attempts to create permanent magnet materials to replace such rare earth cobalt magnets were first made with rare earth/iron binary compounds.

Rare earth/iron compounds exist in fewer types than rare earth/cobalt compounds, and generally have a lower Curie point. Therefore, none of the casting methods and powder metallurgy methods used to magnetize rare earth cobalt compounds have been successful for rare earth cobalt compounds.

A.E. Clark found that spattered amorphous TbFe2 had a high coercive force (lle) of 4.21 and 30 kOe, and 300-350
Ilc-3.4 at room temperature by heat treatment at °C
kOe. Maximum energy product ((BH)IaX) − 7
MGOe (Appl. Phys.
Lett. 23(if), 1973. 842
-645).

J. J. Croat et al. Pr
Ultra-quenched ribbons of NdFe and PrFe using light rare earth elements of I! c=7. 5 kOe. However, when Br is less than 5kG (B II
) m a x only shows 3 to 4 MGOe (
Appl. Phys. Lett. 37. 198
0. 109B. J. AI) p1. Phys. 5
3. (3) 1982. 2404-241)8
).

In this way, the two methods of heat-treating pre-prepared amorphous material and ultra-quenching were known as the most promising means of obtaining rare earth/iron magnets.

However, the materials obtained by these methods are all thin films or ribbons, and are not magnetic materials used in general magnetic circuits such as speakers and motors.

Furthermore, N.C. Koon et al. obtained ultra-quenched ribbons of FeB-based alloys containing heavy rare earth elements by adding La.
s) 0.9 Tbo. osLa0. . , it was found that 11c=9koe could be reached by heat-treating a ribbon with a composition of (Br-5kG, Appl. Phy
s. Lett. 39 (10). 1981. 8
40-842).

L. Kabacof'f' et al.
Noting that B-based alloys facilitate amorphization,
(Feo.Bo, 2) 1-X Pry (x-
Although we created an ultra-quenched ribbon with a composition of 0 to 0.3 atomic ratio), only a few Oe of He could be obtained at room temperature (J. Appl. Phys. 53 (3)
) 1982. 2255-2257).

Magnets obtained from these sputtered amorphous thin films and ultra-quenched ribbons are thin and subject to dimensional limitations, and as such are not practical permanent magnets that can be used in general magnetic circuits. That is, it is impossible to obtain a bulk permanent magnet body having arbitrary shapes and dimensions, such as conventional ferrite and rare earth cobalt magnets. Furthermore, both the grasshopper thin film and the ultra-quenched ribbon are isotropic in nature. Magnetic properties at room temperature are poor, and it is virtually impossible to obtain high-performance magnetically anisotropic permanent magnets from these materials.

Recently, permanent magnets are exposed to increasingly harsh environments - for example. In addition to strong demagnetizing fields caused by thinner magnets and strong reverse magnetic fields applied by coils and other magnets, devices are increasingly exposed to high-temperature environments due to faster speeds and higher loads. In order to stabilize the characteristics in the application,
An even higher coercive force is required. (In general, the idle of a permanent magnet decreases as the temperature rises. Therefore, if IHe at room temperature is small, demagnetization will occur when the permanent magnet is exposed to high temperature. However, if iHc at room temperature is high enough, this (No such demagnetization occurs.) In ferrite and rare earth cobalt magnets, additive elements and different composition systems are used to increase the coercive force, but in this case, the saturation magnetization generally decreases and the (Bi) island ax is also low.

The basic object of the present invention is to provide a new alloy for practical permanent magnets that eliminates the drawbacks of the conventional method.

From this point of view, the present inventors first aimed to create a compound alloy or magnet that has a high Curie point and is stable around room temperature using the R-Fe binary system as a base, and as a result of exploring numerous systems. , especially FeBR-based compounds and FeBRM
It was discovered that these compounds are most suitable for magnetization (Japanese Patent Application No. 145072/1982, Japanese Patent Application No. 200204/1983).

Here, R represents at least one kind of rare earth elements including Y, and light rare earth elements such as Nd and Pr are particularly preferable. B represents boron. M is TI, Zr, ! If
．． Cr, Mn. Nf. Ta, Ge, Sn,
Indicates one or more selected from Sb, B1, Mo, Nb, M, V, and W.

This FeBR magnet has a single Curie point of over 300°C, which is sufficient for practical use. In addition, it can be obtained by the same powder metallurgical method as ferrite and rare earth cobalt, which have not been successful in the R-Pa binary system.

In addition, R has the main composition of resource-rich light rare earth elements such as Nd and P, does not necessarily contain expensive Co or Ss, and has the highest characteristics ((BH)) of conventional rare earth cobalt magnets.
+gax- 31MGOe) significantly exceeds (BH)
It has better characteristics than Ilax3BMGOe.

moreover. The present inventors have developed these FeBR systems. 'FeBR
The M-based compound alloy or magnet exhibits a crystalline Xl1 diffraction pattern that is completely different from that of conventional amorphous thin films or ultra-quenched ribbons, and has a novel tetragonal crystal structure with magnetic anisotropy. (Japanese Patent Application No. 58-94878).

The Curie point of these FeBR-based and PaBRM-based alloys is generally around 300°C to 370°C, but permanent magnet alloys containing 50 atomic percent or less of Co by replacing Fo in these systems have higher Curie points. It has a Curie point and was filed by the same applicant (FeCoBR patent application No. 186883-1983, FoCoBRM patent application No. 58-5813).

The present invention further provides the above-mentioned FeCoBR and FeCoBR.
The high Curie point obtained in M-based alloy magnets and the high maximum energy product (BH) wa that is almost equal to or higher than these.
A specific object of the present invention is to provide an alloy for permanent magnets which has x and can further improve its temperature characteristics, especially if{c.

According to the invention. As R, FeCoBR and FeCoBRM alloys for magnets mainly contain light rare earth elements such as Nd and Pr, and as part of R, R mainly contains heavy rare earth elements as Dy. Tb, Cd, no. Er, Ta. Y
By containing one of b, IHc was further improved while maintaining high (BH) wax in FeCoBR and FeCoBRM systems.

That is, the alloy for permanent magnets according to the present invention is as follows.

Alloy composition is R (consisting of R1 and R2 below) in atomic ratio of 12.5 to 20%, R10.05 to 5%, B4 to
An alloy for permanent magnets, characterized in that the remainder essentially consists of Fe, and a portion of the Fe is replaced with 35% or less (excluding 0%) of Co; however, R, is D
y, Tb. Gd, Ho, Br. Tm, Yb
+R2 is one or more of Nd and Pr. or Nd
and Pr in a total of 80% or more, and the remainder is R and at least one rare earth element containing Y other than R.

Alloy composition is R (consisting of R1 and R2 below) in atomic percentage: 12.5-20%, R10.05-5%, B4-
20%, one or more of the additive elements M below the specified percentage (however, if M includes two or more of the above additive elements, M
The total amount is less than the atomic percentage of the one having the maximum value among the added elements), the remainder substantially consists of Pa, and a part of the Fe is replaced with Co of 35% or less (excluding O%) with respect to the Kanagawa composition. An alloy for permanent magnets, characterized in that R1 is Dy. Tb, Gd. llo, Er
．． Tm. One or more of Yb + R2 is one or more of Nd and P'', or the total of Nd and P'' is 80% or more and the rest is R
, and the addition source M is as follows: Ti 3%, Zr 3.3%, H
r3. 3.3%, Cr 4.5%, Mn
6%, Ni [1%, Ta
7%, Ge 3.5%8n 1.
5%, sb t%, Bi 5%,
MO 5.2%Nb 9%, M5%
, ■5.5%, W5%, In addition, the final product may contain typical impurities below the values shown below.

Cu 2%, 02%, P
2%, Ca 4%,
Mg 4%, 02%, Sl
5%, 32%, however, the total amount of impurities shall be 5% or less.

These impurities are expected to be mixed into the raw materials or during the manufacturing process, but if the amount exceeds the above limit, the properties will deteriorate. Among these, Sl has the effect of raising the Curie point and improving corrosion resistance, but if it exceeds 5%, ill
c decreases. Although Ca and Mg are often contained in large amounts in the R raw material and have the effect of increasing fHc, it is undesirable to contain them in large amounts because they reduce the corrosion resistance of the product.

In the present invention, boron (B) is . Unlike conventional magnetic materials, R-Fe(Co) according to the present invention is not added, for example, as an element that promotes deterioration when creating an amorphous alloy or as an element that promotes sintering in powder metallurgy.
) - It is an essential constituent element of the B tetragonal compound (in addition,
Co replaces part of Fe).

It is possible to most effectively obtain a practical permanent magnet by pulverizing the alloy based on the novel compound of the present invention and then shaping and sintering it.

The alloy for permanent magnets developed by Shosei Joki has a maximum energy product (Bil) a+ax of 20MGO, especially when used most effectively, i.e., when used as a magnetically anisotropic sintered permanent magnet.
A high-performance magnet having a coercive force of i1lclOkOe or more can be obtained while having a coercive force of i1lc1OkOe or more.

The alloy for permanent magnets of the present invention is magnetically stable above room temperature,
As long as it contains Fe(Co)-B-R tetragonal compound having magnetic anisotropy, it can be used in any form, including materials for permanent magnets in known forms such as ingots or powders,
It also includes materials for permanent magnets in any form containing Fe(Co)-B-R tetragonal compounds.

The present invention will be explained in further detail below.

As mentioned above, magnets made using FcBR alloys are expensive (B
H) has max. Itlc is equivalent to the 8112 COLT type magnet, which is a typical high-performance magnet (5
~IOkoe).

This indicates that the magnet is easily demagnetized by being subjected to a strong demagnetizing field or by increasing the temperature by -1, that is, the stability is poor. The Hlc of a magnet generally decreases with increasing temperature. For example, the aforementioned 30MGOe class Sm2Co1
For type 7 magnets and FeBR magnets, it is approximately 5k at 100°C.
It only holds a value of about Oe. (Table 4) Magnetic disk actuators for computers, motors for automobiles, etc. cannot be used in such illcs because they have strong demagnetizing fields and temperature rises. In order to obtain further stability even at high temperatures, it is necessary to have a high Curie point and to increase the IHc value near room temperature.

Furthermore, it is well known that, even near room temperature, the higher the illc, the more stable the magnet is in general against deterioration over time (change over time) and physical disturbances such as impact and contact.

Based on the above, the present inventors conducted a more detailed study focusing on the FeCoBR53E subsystem, and found that the rare earth elements Dy, Tb, Gd, Ilo, Er, Tom,
By combining one or more of Yb and light rare earth elements such as Nd and P, FeBR series, Fe
It was possible to obtain a high coercive force that could not be obtained with a magnet using a CoBR alloy.

Furthermore, it has been found that the component system according to the present invention has the effect of not only increasing iHc but also improving the squareness of the demagnetization curve, that is, further increasing (OH)max.

In addition, the present inventors have developed a magnet using a FeCoBR alloy.
As a result of various studies to increase llc, we have already learned that the following method is effective.

That is, (1) Increase the content of R or B.

(2> Adding the additive element M. (FeCoBRM magnet) However, the method of increasing the content of R or B is as follows:
111c respectively, but as the content increases, Br decreases, and as a result, the value of (Bil)max also decreases.

Further, the additive element M also has the effect of increasing lHc, but as the amount added increases, (BH)+ax decreases and does not lead to a dramatic improvement effect.

The alloy for permanent magnets of the present invention contains rare earth elements R1, mainly heavy rare earth elements, and Nd and Pr as +R2.
The increase in IHe is remarkable when the aging treatment is performed based on the fact that R, B, and Co are mainly in the composition and the composition is within a predetermined range. That is, when a magnetically anisotropic sintered body made of an alloy with the above specific composition is subjected to aging treatment. It increases IHc without impairing the Br value, and also has the effect of improving the squareness of the demagnetization curve. (Bil) wax is almost the same or higher, and the effect is remarkable. In addition, the range of R, B, Co and (Nd, Pr
(or both), 111c of about 10 kOe or more can be achieved even before the aging treatment, and the effect of the aging treatment is further significantly added by the predetermined content of R1 in R.

That is, by using the alloy of the present invention, (Bil)wa
x Tc approx. 3lO while retaining 20MGOe or more
It is possible to provide a high-performance magnet that has sufficient stability shown at ~840° C. and an IHc of 10 kOo or more, and can be applied to a wider range of applications than conventional high-performance magnets.

(BH) wax. The maximum value of iHc is 40.6M each.
GOe (Table 2, 'kl7), 20. OkOe
C Table 2, Nal9) was shown.

R used in the permanent magnet alloy of the present invention is greater than the sum of +R1 and R2, but R includes Y. Nd, Pr.
La, Ce, Tb, Dy. Ito. Er.
Eu. Sn, Cd, Pm. Tm. Yb, Lu
is a rare earth element. Among them, R1 is Dy, Tb,
Gd. llo, r2r, Tm. At least one of the seven types of Yb is used + R2 represents a rare earth element other than the above seven types, and in particular, among the light rare earths, the sum of Nd and P' is 8
Use one containing 0% or more. (However, since Sa is expensive and lowers IHc, it is preferable to have as little as possible. La is often included in rare earth metals as an impurity, but it is still preferable to have a small amount.) These R are not pure rare earth elements. Impurities that are unavoidable during manufacturing within the industrially available range (other rare earth elements, Ca. Mg, F.
(e, TI, C, O, etc.) may be used.

As B (boron), pure boron or ferroboron can be used, and those containing M, 81, C, etc. as impurities can also be used.

When the alloy for permanent magnets of the present invention is used as a magnetically anisotropic sintered permanent magnet (the same applies hereinafter), R is 0.05 to 5% in atomic percentage, where R is the sum of R and R2. 11
2.5 - 20%, B4 - 20%, Co 35% or less, balance Fe in the composition, coercive force IHc about 10 kOe or more, residual magnetic flux density Br 9 kG or more 2. Maximum energy product (BH) wax 2DMGOe or more High coercive force / high Shows the energy product.

0.2-3% of R1. R13~! 9%, B5~11%,
The composition of Co23% or less and the balance Fe is the maximum energy product (
Bit) wax 29MGOe or more, which is a preferable range.

Further, as R, Dy and Tb are particularly desirable.

The reason why the amount of R is set to 12.5% or more is because if the amount of R is less than this amount, Fe will precipitate in the alloy compound of the present invention, and the coercive force will decrease rapidly. The reason for setting the upper limit of R to 20% is. Even if it is more than 20%, the coercive force shows a large value of lOkoe or more, but Br decreases and becomes (BH)+ax20M(io
This is because the required Br cannot be obtained in excess of e.

The amount of R1 can be captured by substituting R as described above.

As for the amount of R, as shown in Table 2, Th2, He increases even with only 0.2% substitution, and it is also seen that the squareness of the demagnetization curve is improved and (Bit) max is increased. R
The lower limit of 1 amount is the effect of file increase and (811) wax
Considering the effect of increase, it is set to 0.05% or more (see Figure 2).As Rlffi increases. ille increases (Table 2, Nα2-7) (13tl) iax is 0
．． It peaks at 4% and then decreases little by little. For example 3
Even with % substitution, (B tl) max is 29MG
oc or higher (see Figure 2).

For applications where stability is particularly required, it is more advantageous to have a higher IHc, that is, to contain more R1.
The elements that make up , are only contained in rare earth ores and are very expensive.

Therefore, the upper limit is set at 5%. When Br;k becomes 4% or less, i He becomes less than lOkoe. Furthermore, an increase in the amount of B also increases <illc, which is the same as an increase in Rffi, but Br decreases. (Bi!)IIlax 20
In order to achieve MGOe or higher, 820% or lower is required.

In the alloy for permanent magnets of the present invention, the temperature characteristics are improved while maintaining (Bil)a+ax high by containing 35% or less of Co. However, in general, when Co is added to an Fe alloy, the amount of Co added is It is difficult to predict the effect of addition, as there are cases where the Curi point increases and cases where it decreases.

In the present invention, when part of the Fe in the FeBR system is replaced with Co, the Curie point gradually increases as the amount of Co substitution increases, as shown in FIG. Substitution of Co is slight (
For example, even 0.1 to 1%) is effective in increasing the Curie point, and as shown in Figure 1, it varies from about 310 to about 64% depending on the amount of substitution.
An alloy with an arbitrary Curie point of 0° C. is obtained. Fe
When replacing with Co, lHc shows a decreasing tendency as the amount of Co increases, but initially (BH)IIlax is . Since the squareness of the demagnetization curve is improved, it becomes slightly larger.

Below 25% Co, Co has other magnetic properties, especially (BH
) It contributes to an increase in the Curie point without substantially affecting the mix, and in particular, it is equivalent or higher at Co23% or less.

When the Co content exceeds 25%, (Bit) max decreases, and when it exceeds 35%, it decreases further, (DI
I) tIla X becomes lower than 20MGOe. In addition, the temperature coefficient (from room temperature to 1
4 (average value at 1°C) is approximately 0.1%/°C or less. The magnet using the PaCoBR alloy of the present invention also showed a blade dew test at 10 (1'c) after magnetization at room temperature.Sl2
COI? Compared to a magnet or an FcBR magnet that does not contain an R1 component, it exhibits an extremely small demagnetization rate and has greatly improved stability.

Note that the same argument regarding Co holds true for the FeCoBRM system, and although the effect of increasing the Curie point varies somewhat depending on the added element of M, the basic tendency is the same.

The additive element M increases 111c and has the effect of increasing the squareness of the demagnetization curve. On the other hand, as the amount of melon added increases, r3' decreases, so (all)a+ax 20MG
In order to have Oe or more, BrQkG or more is required, and the upper limit of each addition amount is determined to be the above-mentioned value or less. When two or more types of M are added, the upper limit of the total M is less than or equal to the maximum value among the upper limit values of the M base lines actually added. For example, when TI, Nf, and Nb are added. It becomes 9% or less of Nb. As for M,
V, Nb, Ta, Mo, W, Cr. Al.
Sn is preferred. Note that, except for some M (Sb, Sn, etc.), the amount of M added is preferably about 3% or less, and preferably 0.1 to 3% (particularly 0.2 to 2%).

The alloy for permanent magnets of the present invention is preferably made into a sintered body in order to most effectively produce a practical permanent magnet, and in that case, the average crystal grain size is 1 to 100a, preferably 2 to 100a, for both FeCoBR and FeCOBRM systems. It is important that the amount is 40 μl, particularly preferably in the range of about 3 to 10 μl. Sintering can be carried out at a temperature of 900-1200°C. The aging treatment can be carried out after sintering at a temperature of 350°C or higher and lower than the sintering temperature, preferably 450 to 800°C. The alloy powder used for sintering has an average particle size of 0.3 to 8 μl (preferably 1 to 40 μl, particularly preferably 2 to 20 μl). Regarding the sintering conditions, etc., we have already submitted patent application No. 1988-88373 filed by the same applicant.
No. 5g-9[)039.

Hereinafter, aspects and effects of the present invention will be explained according to examples. The sample was prepared by the following steps. (Purity is expressed in weight%) (1) The alloy is melted at high frequency and cast in a water-cooled copper mold.The starting materials are electrolytic iron with a purity of 99.9% as Fe, and ferroboron alloy as B (19.38% B, 5. 32%M,0
. 74% Si, 0.03% C, balance Fe), R with a purity of 99.7% or higher (impurities are mainly other rare earth metals). (For Co, electrolytic Co with a purity of 99.9% is used).

(2> Grinding: Coarsely grind to 35 mesh through using a stamp mill. Then finely grind using a ball mill for 3 hours (
3-10 μm).

(3) Orientation and forming in a magnetic field (10 kOe) (1.5 t/
pressurized with cd).

(4> Sintering After sintering and cooling in Ar at 1000 to l'200°C for 1 hour, the obtained sample was processed and polished, and its magnetic properties were examined using an electromagnetic type magnetic property tester.

Example 1. As R, an alloy was made by combining Nd and other rare earth elements, and it was made into a magnet by the above process. The results are shown in Table 1. Among the rare earth elements R. As shown in http~14, Dy. It was found that there are elements (R1) such as Tb and Ho that have a remarkable effect on improving IHe. In addition,
Those with umbrellas indicate comparative examples. In addition, by containing 5% or more of Co. [It is recognized from Table 1 that the 3r temperature coefficient is 0.1%/°C or less'.

Example 2 Alloys were prepared using light rare earth elements, mainly Nd and Pr, and the types and contents of the rare earth elements listed in Example 1 were selected from a wider range, and magnetized by the method described above.

Furthermore, in order to have a further iHc increasing effect, B00
Heat treatment was performed in Ar at ~700°C for 2 hours. The results are shown in Table 2.

Table 2, k-umbrella 1 is a comparative example using only Nd as the rare earth element. Seeds 2 to Na 7 show cases in which Dy is replaced with Nd. As Dyffi increases, 1110 gradually increases, but (BH) wax shows its highest value around 0.4% Dy (see also FIG. 2).

According to Figure 2, Dy begins to show an effect at 0.05%, and as it increases to 0.1% and 0.3%, the effect on illc increases (the horizontal axis in Figure 2 is plotted on a log scale). (It becomes clearer when converted to ). Gd (Nail), Ho (
NalG). Tb(Nal2), Er(N(
113), Yb (Nal4), etc. have similar effects, but Dy and Tb have a particularly remarkable effect on increasing Ha. Among R, elements other than DL 'rb are also 10kO
has llle well above e and is high (Bil) II
It has an ax. (Bil) saw k 3 OMGOe class magnet material with such a high illc has never been found before. Even if Pr is used instead of Nd (Th
15) Or, (Nd + Pr) is 80% of R2
Even if it is above (Nal6). '(BH)a+ax2
Indicates 0MGOc or more.

FIG. 3 shows the demagnetization curve of 0.8% Dy (Table 1, k8) with typical if{c. Fe-B-Nd
It can be seen that the IHc is sufficiently higher than that of the system example (Table 1, Na-tei 1).

Example 3. As the additive element M, TI. Mo, old, M
n, sb, Nl, Ta. Sn+ Ge- 98% W, 99.9% M, 95% (7) Ilr. Also, V and Te Rl. ferrovanadium containing 2% v, ferroniope containing 67.8% Nb as Nb, ferrochrome containing 61.9% C' as Cr and ferrozirconium containing 75.5% 2' as Zr. used.

These were alloyed in the same manner as above, and further 5■ to 7
Aging treatment was performed using DO''C. The results are shown in Table 3.

It is confirmed that a sufficiently high IHc can also be obtained with the FeCoBRM alloy in which the additive element M is added to the FeCoBR alloy. Table 3. The demagnetization curve of Nl'l is shown in Figure 3, curve 3.
Shown below.

(The following is a blank space) 2 Table 3
A new Fe(Co)-B- based on Pr)
The present invention provides an alloy for permanent magnets containing an R-tetragonal compound, and this alloy is particularly useful as a material for permanent magnets. By using this. High residual magnetization, high coercive force. This also makes it possible to provide a magnetically anisotropic sintered permanent magnet with a high energy product. Moreover, the predetermined R (R,,R
By combining 2), the temperature characteristics (especially coercive force) can be further improved while maintaining a high energy product (B However, it is possible to improve the Curie point by one point, and therefore it has extremely high industrial value. In particular, its advantage as a permanent magnet material is extremely remarkable in terms of its main constituent elements when compared with conventional Sm--Co based materials.

Extremely useful.

[Brief explanation of the drawing]

FIG. 1 is a graph showing the relationship between the Co content and the Curie point Tc when Fe is replaced with Co in an embodiment of the present invention. FIG. 2 shows that Nd is R1 in one embodiment of the present invention.
Oy content and I If c when substituted with element Dy
, (B11) max, and FIG. 3 is a graph showing the demagnetization curve of a typical example.

Claims (2)

[Claims] (1) The alloy composition is R in atomic percentage (R_1 and R_2 below)
) 12.5-20%, R_10.05-5%
, B4-20%, the balance consisting essentially of Fe, the Fe
35% or less (excluding 0%) of the total composition
An alloy for permanent magnets, characterized in that o is substituted; however,
R_1 is one or more of Dy, Tb, Gd, Ho, Er, Tm, Yb, R_2 is one or more of Nd and Pr, or Nd
and Pr in a total of 80% or more, and the remainder is at least one rare earth element containing Y other than R_1. (2) The alloy composition is R in atomic percentage (R_1 and R_2 below)
) 12.5-20%, R_10.05-5%
, B4 to 20%, one or more of the additive elements M below the specified percentage (however, if two or more of the above-mentioned additive elements are included as M, the total amount of M is the atom of the one having the maximum value among the additive elements) (% or less), the remainder substantially consists of Fe, and the part of said Fe is 35% or less (excluding 0%) of the total composition
An alloy for permanent magnets, characterized in that Co is substituted with Co; However, R_1 is Dy, Tb, Gd, Ho, Er, Tm,
One or more of Yb, R_2 is at least one of Nd and Pr, or at least one rare earth element in which the total of Nd and Pr is 80% or more and the remainder includes Y other than R_1, and the additional element M is as follows. : Ti 3%, Zr 3.3%, Hr 3.3%, Cr 4.5%, Mn 5%, Ni 6%, Ta 7%, Ge 3.5%, Sn 1.5%, Sb 1% , Bi 5%, Mo 5.2%, Nb 9%, Al 5%, V 5.5%, W 5%.