JPS62134908A - R-b-fe system sintered magnet and manufacture thereof - Google Patents

Abstract

PURPOSE:To remarkably improve the coercive force by adding a nitride of at least one kind of Al, B. CONSTITUTION:To an R-B-Fe system alloy powder having R (R is at least one kind of the rare earth elements containing Y), B and Fe as the essential components or a mixed powder becoming the same composition as that, a nitride powder of at least one kind of B, Al is further blended by 0.05-3.5wt%, and mixing forming, sintering and heat treatment are performed. Sintering is preferably performed in a non-oxide atmosphere for preventing the oxidation of the R element. That is, vacuum, inert gas or reducing gas atmosphere is desirable.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention is an R-B-Fe sintered magnet whose coercive force (iHc) is improved by adding nitride.

[Conventional technology]

In recent years, NdB-Fe-based permanent magnets have been invented that have higher magnetic properties than conventional Sm-Co-based magnets and do not necessarily contain Sm or Co, which are expensive in terms of resources. .

(Sayo et al., J. Appl., Phys., 55 (6)
.

15March 1984. P2O83-2087. and Japanese Unexamined Patent Publication No. 59-46008, No. 59-2042
According to them, a manufacturing method is disclosed in which an alloy ingot obtained by melting and casting is crushed, press-formed while applying a magnetic field as necessary, and then solidified.

[Problem that the invention seeks to solve]

However, with these conventional manufacturing methods, it has not been possible to obtain a sufficiently satisfactory coercive force (iHc) in terms of magnetic properties.

Honkotomei solves the problems of the conventional technology mentioned above, and has a coercive force (
The purpose of this invention is to provide a manufacturing method capable of obtaining an R-B-Fe-based sintered magnet with a large iHc) and excellent magnetic properties.

[Means for solving problems]

That is, the present invention provides R (where R is at least one kind of rare earth elements including Y), B, and Fe as essential components.
-B - Fe-based alloy powder or a mixed powder having the same composition is further blended with at least one nitride powder among the elements 4B, B, and Al in an amount of 05 to 5.5% by weight, It is characterized by mixing, molding, sintering and heat treatment.

To explain the present invention in detail, first, an R-B-Fe alloy powder having a predetermined component or a mixed powder having the same composition is prepared by known means. For example, the alloy powder is prepared by a method of melting and casting an ingot into powder, a method of bath dissolving and atomizing, or a reduction diffusion method using a rare earth oxide as a starting material.

At least a part of the above alloy powder is transition metal powder represented by Fe, poro/powder, rare earth metal powder, B-transition metal alloy powder, R
- Even if a mixed powder substituted with one or more types of transition metal alloy powder is used, the effects of the present invention will not be lost.

In the above powder, 4B, B, Al 9ide powder is added from 0.05 to
Contains 15wt.

If it is less than 0.05% or more than 3.5%, the effect will be small, so it is set at 0.05 to 6.5wt%. The mixed powder obtained by the above method is molded and compacted using a compression press or the like.

The above molding-consolidation is preferably performed at a molding pressure of 0.5 to 10 Val, and if necessary, a magnetic field (5K
Magnetic properties are improved by applying a magnetic field (Oe or more). The series of molding and compaction may be performed wet or dry, and may be performed at a high temperature other than room temperature.

The atmosphere is preferably a non-oxidizing atmosphere, and for example, it may be carried out in a vacuum, an inert gas, or a reducing gas.

The obtained molded body is sintered at a temperature of 900 to 1200°C. If the temperature is less than 900°C, the density will not increase and Br will not be sufficient (this is because if it exceeds 1200°C, Br and squareness will decrease.

Sintering is preferably performed in a non-oxidizing atmosphere to prevent oxidation of the R element. In other words, a vacuum, an inert gas, or a reducing gas atmosphere is preferable.The temperature increase rate from room temperature during sintering is not particularly specified, but
By holding the temperature in the 00°C temperature range for at least 0.5 hours, the temperature uniformity of the heated part is improved, and it is also possible to perform scale removal treatment in a vacuum. Cracking of salts (hydropyrolysis method) can also be carried out in a hydrogen gas atmosphere. Therefore, the atmosphere for sintering may be vacuum, inert gas (e.g. Ar), or reducing gas (e.g. Hz).
) is preferable in a non-oxidizing atmosphere such as 0. The cooling rate after heating and holding is not particularly specified, but 0.5 to 100 C/min is good, and generally 1 to 10 C/min is good.
This is because the variation in magnetic properties due to subsequent heat treatment will be reduced.0Also, cooling may be performed once to room temperature, or alternatively, sintering and heat treatment may be performed to about 500℃ and then raised again for the next heat treatment. After 0 or more sintering, which may be performed continuously, in order to further improve the magnetic properties,
Aging treatment is performed at 500 to 700°C, but if necessary, an intermediate heat treatment of holding and slow cooling at 800 to 1000°C can be performed before aging to further improve the magnetic properties. As with the above-mentioned sintering, heat treatments such as aging treatment and intermediate heat treatment are preferably performed in a non-oxidizing atmosphere.
It may be maintained at 0°C for at least 0.5 hours and then rapidly cooled. This is because if the temperature is less than 500°C, the effect will be small, and if it exceeds 700°C, the magnetic properties will deteriorate.

Next, to explain the reason for limiting the components of the rare earth/boron/iron sintered magnet to which the present invention is applied, the magnet of the present invention contains the rare earth element R (where R is at least one of the rare earth elements including Y).
Species), boron and iron are essential elements.
Pr) or a mixture of sora (didim) is preferred;
Another lantern (La).

Cerium (Ce), Terbium (Tb), Dysprosium (Dy), Holmium (Ho), Erbium (Er), Europium (Eu), Samarium (S)
m), gadolinium (Gd), glomethium (Pm)
), thulium (Tm), ytterbium (Yb)
, lutetium (Lu), and yttrium (Y), with a total amount of 8 to 30 atoms. This is because a sufficient coercive force cannot be obtained with less than 8 atoms, and with more than 30 atoms, the residual magnetic flux density decreases. Boron B has 2 to 28 atoms. This is because if it is less than 2 atoms, a sufficient coercive force cannot be obtained, and if it exceeds 28 atoms, the residual magnetic flux density decreases and excellent magnetic properties cannot be obtained. Fe is an essential element other than R and B and contains 40 to 90 atoms.

Below 40 atoms, the residual magnetic flux density (Br) decreases, and 9
This is because if it exceeds 0 atoms, a high coercive force (iHc) cannot be obtained.

Rare earth/boron/iron sintered magnets can be created using the above R-B and Fe as essential elements, but as described below, even if some of the iron is replaced with other elements or impurities are included, this defense does not apply. The effect will not be lost.

That is, in place of Fe, less than 50 atoms of Co p8
Ni may be substituted with less than 50 atoms of Co. If Co exceeds 50 atoms, high fHc cannot be obtained, and if Ni exceeds 8%, high Br cannot be obtained. In addition, as an element other than the above, one or more of the A elements below the specified atom number (however, if two or more types are included, the total amount of A elements is less than or equal to the maximum value of the contained A element) kReplaced with Fe element However, the effects of the present invention are not lost. The A element is as follows: 0 Next, examples of the present invention will be described, but the present invention is not limited to these examples.

〔Example〕

Example 1 16Nd-8B-dissolved to form residual Fe (atomic atoms),
An alloy ingot was obtained. The alloy ingot was made into a fine powder with an average particle size of 3.5 μm using a Geo crusher, a brown mill, and a jet mill, and then AlN powder (average particle size of 1
．． 5 μrn) as shown in Table 1 to form raw material powder. Table 1 The obtained raw material powder was placed in a magnetic field (10K
Oe) The obtained molded body was molded in vacuum (10 Torr
), sintered at 1100°C for 2 hours, cooled in the furnace, and heated again at 610°C.
After heat treatment for 1 hour at °C, it was rapidly cooled and subjected to evaluation of magnetic properties. The results are shown in Table 1.

See Table 1! 20<, it can be seen that the coercive force (iHc) is significantly improved by adding AlN (A2 to A7) compared to the case where AlN is not added (A1). However, A
In the 3.8% lN additive material (A7), the residual magnetic flux density (Br
Example 2 As shown in Table 2, nitride powder (average particle size 1.5-2.5)
μm) were blended and mixed, molded, sintered, and heat treated in the same manner as in Example 1, and the magnetic properties were evaluated. The results are shown in Table 3. As shown in Table 6, the addition of BN (width: 8, 9.10) also improves the coercive force, similar to AlN. , 12) also shows an improvement in coercive force. However, when the amount added is excessive (AIo, 12), as in 47, a significant decrease in Br occurs.

〔Effect of the invention〕

Claims (2)

[Claims] 1. R (where R is at least one rare earth element including Y), B-Fe alloy powder containing B and Fe as essential components, or a mixed powder having the same composition as B.
, at least one kind of nitride powder among the elements of Al in weight%
A method for manufacturing an R-B-Fe-based sintered magnet, which comprises blending 0.05 to 3.5% of R-B-Fe based sintered magnets, and performing mixing, molding, sintering, and heat treatment. 2. R- characterized in that 0.05 to 3.5% by weight of at least one nitride powder of the elements B and Al is blended.
B-Fe based sintered magnet.