JPS60159152A - Permanent magnet alloy - Google Patents

Abstract

PURPOSE:To increase the Curie point and coercive force (Hc) of a permanent magnet and to improve the thermal stability by substituting Si for part of B in the magnet made of an intermetallic compound consisting of a rare earth metal, Fe, Co and B. CONSTITUTION:An alloy having a composition represented by formula 1 (where R is one or more kinds of rare earth elements, 0<=x<=0.5, 0.02<=y<=0.3, 0.002<=z <=0.15, and 4<=A<=7.5) is melted in vacuum or a gaseous Ar atmosphere, and the molten alloy is cast into an ingot. This ingot is pulverized in a gaseous N2 atmosphere, and the resulting powder is press-molded in a magnetic field of 15kOe. The molded body is sintered in a gaseous Ar atmosphere, and the sintered body is rapidly cooled and heat treated at 400-800 deg.C. Thus, an intermetallic compound having a composition contg. Si substituted for part of B is formed, and a permanent magnet made of the compound consisting of rare earth metals, Fe, Co, B and Si is obtd. This permanent magnet has an increased Curie point, increased coercive force (Hc) and superior thermal stability.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an intermetallic compound permanent magnet material consisting of a rare earth metal (hereinafter abbreviated as R) and 1-0.

RFe alloys, e.g. R2F, as known from
e+7 has higher saturation magnetization than R-Cc gold alloy,
It is a permanent magnet material that does not contain expensive Co and has a high boron citre. However, the LHC required for the permanent magnet IJ fl could not be obtained,
It remained in place for a long time. In recent years, with the progress of liquid quenching technology, this method has been successfully applied to R-Fe alloys to obtain high coercive force. , (for example, J,
J., Croat.

Journal of At) Plied Physi
cs 52< 3) Marct+ 1981.2509
”Magnetic properties of me
lt-3pHn pr -Fe alloys'') Zarani, N, C, KOOll et al.
A high coercive force is achieved by ultra-quenching the e-B alloy and avoiding aging crystallization at 600 to 8oO<0>C. (N,
C, Koon et al Appl, phys.

1-etter 39(10) 15 (1981)
840 “MaClnetiQproper eyes as
of Amorphous and Crystalli
zed "%J12 Bo, +9 ) o, q ding bo, o
s l-ao, os”, 4J 17tl l1j3
58-123853) However, the above manufacturing method requires a mixed state of crystalline and amorphous materials, and the form of the obtained material is generally limited to powder or ribbon.

Shikatsu-C1 To be used as a permanent magnet abrasive material, it is necessary to make it into bulk by compression molding or the like.

Also, the powder produced by ultra-quenching is isotropic and has an angle of 4°! It is difficult to magnetize and has many problems in practical use.

On the other hand, in the combination, crystalline Nd-Fe-8 was used, and high properties were obtained by molding and sintering in a magnetic field to obtain anisotropy. (29th 3MConf, 1983 booklet P
110. 3 essionE B , E B-1'''
New Material for permanent
t Magnets on a base of Nd
and Fe”) obtained magnetic properties are 35-40
MGoe is the highest among rare earth magnets. However, the wood quality that has been published has the drawbacks of a low curri point and poor thermal stability, which has been a major obstacle to practical application.

The present invention has been made to improve the thermal stability of these Nd-C-3 alloys, and has solved the drawbacks mentioned above by improving the Curie point and Hc. be. As a result of various studies, the inventors found that partial substitution of 13 with 81, which is an important constituent element toward the Curie point, is effective.

The alloy system of the present invention is R(Fe1-X-2-7coeBASiy)A (where R: one type or a combination of two or more rare earth elements, 0≦X≦0.5. 0.02≦ y≦0.
3. 0.002≦z≦0.15, 4≦, A≦7
．． 5) T". In the present invention, when the CO substitution amount x exceeds 0.5, 4πi
Although the effect of the present invention can be obtained even in the case where the decrease in s is large and o and oi are not swirled, the improvement of one Curie point is insufficient, so it is preferable to include i of 0.01 or more. If the B substitution My is less than 0.02, the Curie point will not rise above R and high zl-IC will not be obtained. On the other hand, when y exceeds 0.3, the Curie point 4π15 decreases, and a phase with unfavorable magnetic properties appears. Si substitution Hz
If it is less than 0.002, a single Curie point will not be formed, and the heat treatability will not be improved, so that a high E11c cannot be obtained after sintering. When 2 is 0.15 or more, 4πIs decreases (
) Permanent magnetic materials are not desirable. When A is less than 4, 4π7s decreases, and as it exceeds 7.5, an Fe-rich lν phase appears and -1C decreases.

In principle, Si substitution m is combined with B, and if 5in (atomic ratio) odd to the sum of B and Si m is 0.6 or more, substitution of Co for one Curie point also improves Curie point, but as mentioned above, excessive Substitution causes a decrease in 4πIs, a decrease in squareness, and a decrease in zHc. However, it is necessary to determine the composition by taking into account the magnetic properties and required temperature properties.

The permanent magnet according to the present invention is generally manufactured by the following steps: ingot creation by melting, l) crushing, forming in a magnetic field, sintering, and heat treatment. - The melting is carried out in the usual manner in Ar or in vacuum. It is also possible to use ferroboron for B. The process of pulverization is divided into coarse pulverization and fine pulverization. Coarse pulverization is performed using a stamp mill, jaw pusher, brown mill, disc mill, and fine pulverization is performed using a jet mill, vibration mill, ball mill, etc. Both are carried out in a non-oxidizing atmosphere to prevent oxidation, and organic solvents and inert gases are used. The grinding particle size is 3-5 μm (F, S, S.

S,) is desirable. Molding in a magnetic field is necessary to improve the degree of orientation and create anisotropy, and is generally used in vertical magnetic field forming (the direction of pressure and the direction of magnetic field application are parallel), and in horizontal magnetic field forming (the direction of pressure and the direction of magnetic field application are perpendicular). is used.

Horizontal magnetic field forming is better than vertical magnetic field forming in terms of orientation 2 degrees. Sintering is performed in an inert gas such as Aj, 1-1e or in fresh air. Furthermore, sintering in H2 gas is also possible.

Rapid cooling is preferable for cooling after sintering. The heat treatment is performed at a temperature in the range of 400 to 800°C, although it varies depending on the type and composition of the rare earth element used.

Further effects of 3i substitution can be obtained by rapid cooling after sintering.
, zl-IC can be obtained sufficiently, and high ml'C can be obtained without additional heat treatment.

The present invention will be explained below with reference to Examples.

Example 1 Pr (F(3,,9B,,1-Z S 17 ) 5
An alloy having the following composition was produced by arc melting. The obtained ingots 1 to 1 were coarsely pulverized using a disk mill, adjusted to a size of 32 mesh or less, and then finely pulverized using a shedding mill. The grinding medium is N2 gas, and the grinding particle size is 3.5 μm (F,
S, S, S,'). The obtained fine powder) was crushed at 15K.
Transverse magnetic field molding was performed in a magnetic field of Oe. Molding pressure is 2tOn/
It is C1112. The obtained molded body was sintered in an Ar atmosphere, and after sintering, it was cooled in an Ar air flow. The magnetic properties obtained were as shown in Table 1. It can be seen that □Hc obtained by S1 substitution is improved. Table 2 shows the curri of the obtained magnet.

It can be seen that an improvement of one Curie point was achieved by the Si substitution.

Table 1 Table 2 Example 2 N d (F eol, C0,4Boo, S 'o
, o4)5.5 was melted, crushed, and molded in the same manner as in Example 1.

The obtained molded body was sintered in vacuum at 1100° C. for 2 hours.

The obtained magnetic properties were B r ~11800G BHC ~103000°1IJ10~17000(3@) maX ~34.2M G Oe. One point of Curi was 396°C. This magnet iox 1
0x 10 (+no+) P=-2,5)L
, when heated to 150℃, the till reduction rate was 4.3%.
Met. N d (F eo, 9'
B, , , ), s exhibited the following characteristics.

Br-12500G 811C ~ 85000s Engineering Hc ~ 89000s (B l-1) max ~37. IM GOe Curie point ~ 294℃ Demagnetization rate ~ 31.5% (heated at 150℃) Example 3 N d (F eo, g3C000T5 BO, l19
S'0.04) b, 3 alloy was melted, crushed and molded in the same manner as in Example 1.

The compacted body was sintered at 1140° C. for 2 hours in an Ar atmosphere.

The obtained characteristics are as follows:
l'l! The magnetic rate was 6.8%. (P--2,5) Example 4 N'0. S [:'rO, 5(F eo, q2-I
An alloy of Bo, oBSix)6.1 was melted, crushed, and molded in the same manner as in Example 1. The obtained molded body is 1
Sintering was carried out in hydrogen at 120° C. for 2 hours. The obtained magnetic properties are shown in Table 3. In a relatively high A composition region, the effect of adding a small amount of 3i was remarkable.

Table 3

Claims (1)

[Claims] R(Fe Co B Si ) (where +-x-y-
z x y! Halo: One type or combination of two or more types of rare earth elements, O≦×≦
0.5. 0.02≦y≦0.3. 0.002≦2≦
0.15.4≦A≦7.5) A permanent magnetic alloy characterized by having the following composition.