JPH11106803A - Production of rare earth magnet powder having excellent magnetic property - Google Patents

Abstract

PROBLEM TO BE SOLVED: To particularly increase residual magnetic flux density in powder and to reduce the temp. coefficient of coercive force thererin by successively subjecting an alloy raw material to hydrogen occluding preliminary treatment, hydrogen occluding treatment and dehydrogenating treatment, thereafter executing cooling and pulverizing it. SOLUTION: The temp. of an alloy raw material contg. rare earth elements including Y, Fe, B or the like is subjected to hydrogen occluding preliminary treatment in which its temp. is raised to a prescribed one in the range of >1000 to 1200 deg.C in an inert gas or in a vacuum atmosphere, it is held to this temp., thereafter, hydrogen is introduced therein to change the atmosphere to a hydrogen one, successively, it is held to the same temp., and, after that the temp. is dropped to a prescribed temp. in the range of 800 to 1000 deg.C. Then, the alloy raw material is subjected to hydrogen occluding treatment in which hydrogen is occluded therein to promote the phase transformation. Furthermore, it is subjected to dehydrogenerating treatment in which the atmosphere is changed to a vacuum one or an inert gas one of >=1 Torr hydrogen partial pressure, and it is held to a prescribed temp. in the range of 500 to 900 deg.C to forcedly release hydrogen from the alloy raw material, by which the phase transformation is promoted, and, thereafter, cooling and pulverizing are executed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a rare earth magnet powder having excellent magnetic properties, and more particularly to a method for producing a rare earth magnet powder having a high residual magnetic flux density (Br) and a small temperature coefficient of coercive force. It is about the method.

[0002]

2. Description of the Related Art Conventionally, as a method for producing a rare earth magnet powder having excellent magnetic properties, (a) a rare earth element containing Y (hereinafter referred to as R) and Fe or a part of Fe
(Hereinafter referred to as T), B as a main component, and Si, Ga, Zr, Nb, Mo, Hf, T
One or more of a, W, Al, Ti, and V (hereinafter, referred to as M): An alloy material containing 0.001 to 5.0 atomic% (hereinafter, this alloy material is referred to as RT- BM-based alloy raw material) in an Ar gas atmosphere at a temperature of 600 to 1
The RTBM-based alloy raw material is treated with H ₂ gas or H ₂ gas by homogenizing at 200 ° C. or without homogenizing.
Room temperature to 5 in a mixed atmosphere of gas and inert gas
The temperature is raised to 100 to 1000 ° C. and held, and a hydrogen absorbing process is performed. Subsequently, in a vacuum atmosphere, the temperature is maintained at 500 to 1000 ° C. to perform dehydrogenation, then cooled and pulverized to produce a rare earth magnet powder. (Japanese Unexamined Patent Publication No. 2-4901), (ii) homogenizing or processing the RTBM-based alloy raw material while maintaining the temperature at 800 to 1200 ° C. in an Ar gas atmosphere. Without treatment, the RTBM-based alloy raw material was heated from room temperature to a temperature of 750 to 950 ° C. and kept in a pressurized H ₂ gas atmosphere of 1.2 to 1.6 kgf / cm ^2. And then dehydrogenation treatment in a vacuum atmosphere while maintaining the temperature at 500 to 800 ° C.
Then, it is cooled and pulverized to produce a rare earth magnet powder having a small temperature coefficient of coercive force (WO 94/1).
5345), (c) After heating the RTBM-based alloy raw material to a temperature range of 750 ° C. or higher in an inert gas atmosphere, H ₂ gas of 10 to 1000 Pa was introduced. H
₍₂₎ A hydrogen absorption treatment is performed in a gas atmosphere at 750 to 950 ° C. for 30 minutes to 8 hours, followed by Ar or He
Absolute pressure by gas: Rare earth magnet having a small temperature coefficient of coercive force after dehydrogenating by holding at a temperature of 700 to 900 ° C. for 5 minutes to 8 hours in a reduced pressure gas stream of 50 to 100 Pa, then cooling and pulverizing. Method for producing powder (JP-A-7-767)
No. 08 publication) and the like. In these methods, it is also known that cooling after the dehydrogenation treatment is performed while flowing Ar gas.

FIG. 3 shows the temperature of the method (b) which can produce a rare earth magnet powder having a small coercive force temperature coefficient.
FIG. 4 shows a pattern diagram illustrating a relationship between time and atmosphere. FIG.
As shown in the pattern diagram of the above, the hydrogen occlusion treatment of the above method (b) is carried out in a pressurized H ₂ gas atmosphere of hydrogen pressure: 1.2 to 1.6 kgf / cm ² at a temperature of 750 to 950 ° C. It is carried out while heating and holding.

[0004]

However, a method for producing a rare earth magnet powder having a sufficient residual magnetic flux density (Br) has not yet been obtained. In particular, a rare earth magnet powder of an RTBM alloy has been used. Since the coercive force decreases significantly with temperature, there is a need for a method of producing rare earth magnet powder in which the coercive force does not decrease with temperature. In the method for producing a rare earth magnet powder according to the above (b), the RTBM-based alloy raw material is subjected to a hydrogen occlusion treatment in a pressurized H ₂ gas atmosphere of 1.2 to 1.6 kgf / cm ^2. Is a method of obtaining a rare earth magnet powder having a small temperature coefficient of coercive force, but even with this method, a rare earth magnet powder having a sufficiently small temperature coefficient of coercive force could not be obtained.

[0005]

Means for Solving the Problems Accordingly, the present inventors have:
As a result of conducting research to develop a method for producing a rare earth magnet powder in which the residual magnetic flux density (Br) is further improved and the temperature coefficient of the coercive force is further reduced as compared with the prior art, (a) R-T
-B-M based alloy raw material in inert gas atmosphere or 1To
room temperature to over 1000 ° C in a vacuum atmosphere of rr or less
After the temperature is raised to a predetermined temperature in the range of 200 ° C. or less and maintained at the same temperature, hydrogen is introduced at the same temperature to convert it into a hydrogen atmosphere, and subsequently maintained within the same temperature range in the hydrogen atmosphere. By performing a hydrogen storage pretreatment for lowering the temperature to a predetermined temperature in the range of 800 to 1000 ° C. without holding or maintaining, and then maintaining the temperature in the range of 800 to 1000 ° C. in the hydrogen atmosphere, The RTB-
The M-based alloy raw material is subjected to a hydrogen storage treatment for absorbing hydrogen to promote phase transformation, and further converted into a vacuum atmosphere of 1 Torr or less or an inert gas atmosphere of hydrogen partial pressure: 1 Torr or less. A dehydrogenation treatment for promoting phase transformation by forcibly releasing hydrogen from the RTBM-based alloy raw material by maintaining a predetermined temperature in a range of 900 ° C. is performed, then cooling, and then pulverizing. The resulting rare earth magnet powder has a further improved residual magnetic flux density (Br) and a further reduced temperature coefficient of coercive force.
(B) Hydrogen is introduced at a predetermined temperature in the range of higher than 1000 ° C. and lower than 1200 ° C. to convert it into a hydrogen atmosphere, and subsequently kept or kept in the same temperature range in the hydrogen atmosphere. Hydrogen storage pretreatment for lowering the temperature to a predetermined temperature in the range of 800 to 1000 ° C. and maintaining the temperature in the range of 800 to 1000 ° C. in the hydrogen atmosphere to prepare the RTBM alloy raw material. The hydrogen atmosphere in the hydrogen storage treatment for promoting the phase transformation by absorbing hydrogen is preferably a hydrogen pressure of 0.5 to 10 atm. (C) The RTBM-based alloy raw material is previously Ar It is preferable to perform the homogenization treatment while maintaining the temperature at 600 to 1200 ° C. in a gas atmosphere, but it has been found that the homogenization treatment is not required.

[0006] The present invention has been made based on such knowledge, and (1) an RTBM-based alloy raw material
In an inert gas atmosphere or a vacuum atmosphere of 1 Torr or less, the temperature is raised from room temperature to a predetermined temperature in a range of more than 1000 ° C. and 1200 ° C. or less, and after maintaining the same temperature, hydrogen is introduced at the same temperature. After converting to a hydrogen atmosphere and subsequently maintaining the same temperature range in the hydrogen atmosphere, 800 to 1
A hydrogen storage pretreatment for lowering the temperature to a predetermined temperature in the range of 000 ° C.
By maintaining at a predetermined temperature in the range of 000 ° C.,
The R-TBM-based alloy raw material is subjected to a hydrogen-absorbing treatment for absorbing hydrogen to promote phase transformation, and the atmosphere is further reduced to 1 Ton.
rr or less, or hydrogen partial pressure: converted to an inert gas atmosphere of 1 Torr or less.
By maintaining at a predetermined temperature within the range of 00 ° C., R-
A method for producing a rare earth magnet powder having excellent magnetic properties, which is subjected to a dehydrogenation treatment for forcibly releasing hydrogen from a TBM-based alloy raw material to promote phase transformation, followed by cooling and then grinding; 2) The RTBM-based alloy raw material is heated from room temperature to a predetermined temperature in the range of more than 1000 ° C. and 1200 ° C. or less in an inert gas atmosphere or a vacuum atmosphere of 1 Torr or less. After that, hydrogen was introduced at the same temperature to convert it into a hydrogen atmosphere, and immediately
Preliminary hydrogen storage treatment for lowering the temperature to a predetermined temperature in the range of 00 to 1000 ° C. is performed.
By maintaining the temperature at a predetermined temperature in the range of 00 to 1000 ° C., the R-T-B-M-based alloy raw material is subjected to a hydrogen storage treatment for absorbing hydrogen to promote phase transformation, and further, the atmosphere is reduced to 1 Torr or less. Vacuum atmosphere or hydrogen partial pressure: 1To
The inert gas atmosphere is converted to an inert gas atmosphere of rr or less, and hydrogen is forcibly released from the RTBM alloy material by maintaining the atmosphere at a predetermined temperature in the range of 500 to 900 ° C. A method for producing a rare earth magnet powder having excellent magnetic properties, which is subjected to a dehydrogenation treatment for promoting phase transformation, then cooled and then pulverized; After raising the temperature from room temperature to a predetermined temperature in the range of more than 1000 ° C. and 1200 ° C. or less in an atmosphere or a vacuum atmosphere of 1 Torr or less, hydrogen is introduced at the same temperature, and 0.5 to 10 atm ( More preferably, 1 to 5
(Atmospheric pressure) and continuously maintained in the same temperature range in this hydrogen atmosphere,
By performing a hydrogen storage pretreatment for lowering the temperature to a predetermined temperature within the range of 0.5 to 10 atmospheres, and then maintaining the temperature at a predetermined temperature within the range of 800 to 1000 ° C. in the hydrogen atmosphere of 0.5 to 10 atm. A hydrogen storage treatment is performed to promote phase transformation by storing hydrogen in the TBM-based alloy raw material, and the atmosphere is further reduced to a vacuum atmosphere of 1 Torr or less or a hydrogen partial pressure of 1T.
orr or less, and by maintaining the atmosphere at a predetermined temperature in the range of 500 to 900 ° C., the hydrogen is forcibly released from the RTBM-based alloy raw material to reduce the phase. A method for producing a rare earth magnet powder having excellent magnetic properties, which is subjected to a dehydrogenation treatment for promoting transformation, followed by cooling and then pulverization. (4) The RTBM-based alloy raw material is placed in an inert gas atmosphere. After the temperature is raised from room temperature to a predetermined temperature in a range from more than 1000 ° C. to 1,200 ° C. or less in a vacuum atmosphere of medium or 1 Torr or less, hydrogen is introduced at the same temperature, and 0.5 to 10 atm. Preferably, 1 to 5
Atmospheric pressure), immediately perform a hydrogen storage pretreatment in which the temperature is lowered to a predetermined temperature in the range of 800 to 1000 ° C. in the hydrogen atmosphere, and then perform the hydrogen absorbing atmosphere in the 0.5 to 10 atm hydrogen atmosphere. By maintaining the temperature at a predetermined temperature within the range of ~ 1000 ° C, the R-T-B-M-based alloy raw material is subjected to a hydrogen storage treatment for absorbing hydrogen to promote phase transformation, and further, the atmosphere is set to 1 Torr or less. A vacuum atmosphere or a hydrogen partial pressure is converted into an inert gas atmosphere of 1 Torr or less, and is maintained at a predetermined temperature in the range of 500 to 900 ° C. in this atmosphere to forcibly remove the RTBM alloy material. After being subjected to a dehydrogenation treatment for releasing hydrogen to promote phase transformation, followed by cooling and then pulverization, and a method for producing a rare earth magnet powder having excellent magnetic properties.

In carrying out the method for producing a rare-earth magnet powder of the present invention, the RTBM-based alloy raw material is homogenized by maintaining the material at a temperature of 600 to 1200 ° C. in a vacuum or Ar gas atmosphere. Is preferred. Therefore, the present invention provides (5)
Temperature: The RTBM alloy material homogenized by maintaining the temperature at 600 to 1200 ° C. is heated from room temperature to 1 in an inert gas atmosphere or a vacuum atmosphere of 1 Torr or less.
The temperature is raised to a predetermined temperature in the range of more than 2,000 ° C. and 1,200 ° C. or less, and after maintaining the same temperature, hydrogen is introduced at the same temperature to be converted into a hydrogen atmosphere. After being held in the range, a hydrogen storage pretreatment is performed to lower the temperature to a predetermined temperature in the range of 800 to 1000 ° C.
Then, by maintaining the RTB at a predetermined temperature in the range of 800 to 1000 ° C. in this hydrogen atmosphere,
-M-alloy material is subjected to a hydrogen storage treatment for absorbing hydrogen to promote phase transformation, and further converted to a vacuum atmosphere of 1 Torr or less or an inert gas atmosphere of hydrogen partial pressure: 1 Torr or less. By maintaining a predetermined temperature in the range of up to 900 ° C., forcibly releasing hydrogen from the RTBM-based alloy raw material to perform a dehydrogenation treatment for promoting phase transformation, cooling, and then cooling. Method for producing a rare earth magnet powder having excellent magnetic properties to be pulverized, (6) in vacuum or Ar gas atmosphere, temperature: 600 to 1200 ° C
The RTBM alloy raw material homogenized by holding at a temperature from room temperature to 1000 ° C. to 1200 ° C. in an inert gas atmosphere or a vacuum atmosphere of 1 Torr or less.
After the temperature was raised to a predetermined temperature in the following range and maintained at the same temperature, hydrogen was introduced at the same temperature to convert it into a hydrogen atmosphere, and immediately in the hydrogen atmosphere, a predetermined temperature in a range of 800 to 1000 ° C. By performing a hydrogen storage pretreatment for lowering the temperature to a predetermined temperature, and then maintaining the predetermined temperature within a range of 800 to 1000 ° C. in the hydrogen atmosphere, the RTBM is maintained.
The system alloy material is subjected to a hydrogen storage treatment for absorbing hydrogen to promote phase transformation, and further converted to an atmosphere of a vacuum of 1 Torr or less or an inert gas atmosphere of hydrogen partial pressure of 1 Torr or less. A dehydrogenation treatment for promoting phase transformation by forcibly releasing hydrogen from the RTBM-based alloy raw material by maintaining a predetermined temperature in a range of 900 ° C. is performed, then cooling, and then pulverizing. (7) R-T-B-M-based alloy raw material homogenized by holding at a temperature of 600 to 1200 ° C in a vacuum or Ar gas atmosphere In an inert gas atmosphere or a vacuum atmosphere of 1 Torr or less from room temperature to a predetermined temperature in the range of more than 1000 ° C. and 1200 ° C. or less, and then hydrogen is introduced at the same temperature. .5～10 atm (more preferably,
(1 to 5 atm.), Continuously maintained in the same temperature range in this hydrogen atmosphere,
By performing a hydrogen storage pretreatment for lowering the temperature to a predetermined temperature in the range of 00 ° C., and then maintaining the temperature in the hydrogen atmosphere of 0.5 to 10 atm at a predetermined temperature in the range of 800 to 1000 ° C., The R-T-B-M alloy raw material is subjected to a hydrogen storage treatment for absorbing hydrogen to promote phase transformation, and further converted into an atmosphere of a vacuum of 1 Torr or less or an inert gas atmosphere of a partial pressure of hydrogen of 1 Torr or less. By maintaining a predetermined temperature in the range of 500 to 900 ° C. in this atmosphere, hydrogen was forcibly released from the RTBM-based alloy raw material to perform a dehydrogenation treatment for promoting phase transformation. Thereafter, the mixture is cooled and then pulverized to produce a rare earth magnet powder having excellent magnetic properties. (8) R homogenized by maintaining the temperature at 600 to 1200 ° C. in a vacuum or Ar gas atmosphere. The temperature of the TBM-based alloy raw material is raised from room temperature to a predetermined temperature in a range from more than 1000 ° C. to 1,200 ° C. or less in an inert gas atmosphere or a vacuum atmosphere of 1 Torr or less, and then maintained at the same temperature. To convert it to a hydrogen atmosphere of 0.5 to 10 atm (more preferably 1 to 5 atm), and immediately
By performing a hydrogen storage pretreatment for lowering the temperature to a predetermined temperature in a range of 1000 ° C., and then maintaining the temperature in a hydrogen atmosphere of 0.5 to 10 atm at a predetermined temperature in a range of 800 to 1000 ° C., The R-T-B-M alloy raw material is subjected to a hydrogen storage treatment for absorbing hydrogen to promote phase transformation, and further converted into an atmosphere of a vacuum of 1 Torr or less or an inert gas atmosphere of a partial pressure of hydrogen of 1 Torr or less. By maintaining a predetermined temperature in the range of 500 to 900 ° C. in this atmosphere, hydrogen was forcibly released from the RTBM-based alloy raw material to perform a dehydrogenation treatment for promoting phase transformation. Thereafter, the method is characterized by a method for producing a rare earth magnet powder having excellent magnetic properties, followed by cooling and then grinding.

In order to make the method for producing a rare earth magnet powder of the present invention easier to understand, a description will be given with reference to a pattern diagram showing the relationship between atmosphere, temperature and time. 1 and 2
1 is a pattern diagram of a method for producing a rare earth magnet powder according to the present invention. FIG. 1 shows that the RTBM-based alloy raw material of (3) is heated from room temperature to over 1000 ° C. and 1200 ° C. in an inert gas atmosphere or a vacuum atmosphere of 1 Torr or less.
After the temperature is raised to and maintained at a predetermined temperature in the following range, hydrogen is introduced at the same temperature to convert the atmosphere to a hydrogen atmosphere of 0.5 to 10 atm. After the holding, a hydrogen storage pretreatment is performed to lower the temperature to a predetermined temperature in the range of 800 to 1000 ° C.
By maintaining a predetermined temperature within a range of 800 to 1000 ° C. in a hydrogen atmosphere of 5 to 10 atm, the RT-
The BM-based alloy raw material is subjected to a hydrogen storage treatment for absorbing hydrogen to promote phase transformation, and is further converted to a vacuum atmosphere of 1 Torr or less or an inert gas atmosphere of hydrogen partial pressure: 1 Torr or less. A dehydrogenation treatment for promoting the phase transformation by forcibly releasing hydrogen from the RTBM-based alloy raw material by maintaining the temperature at a predetermined temperature in the range of 500 to 900 ° C. is performed, followed by cooling. FIG. 4 is a pattern diagram of a method for producing a rare earth magnet powder having excellent magnetic properties, which is then ground.

FIG. 2 shows the RTBM of (4).
The system alloy raw material is heated from room temperature to 1000 ° C. to 1200 ° C. in an inert gas atmosphere or a vacuum atmosphere of 1 Torr or less.
After the temperature is raised to and maintained at a predetermined temperature within a range of not more than 0 ° C., hydrogen is introduced at the same temperature to convert the atmosphere into a hydrogen atmosphere of 0.5 to 10 atm. Pretreatment for lowering the temperature to a predetermined temperature in the hydrogen atmosphere, and then, in a hydrogen atmosphere of 0.5 to 10 atm.
By maintaining the temperature at a predetermined temperature in the range of 00 to 1000 ° C., the R-T-B-M-based alloy raw material is subjected to a hydrogen storage treatment for absorbing hydrogen to promote phase transformation, and further, the atmosphere is reduced to 1 Torr or less. Vacuum atmosphere or hydrogen partial pressure: 1To
rr or less and converted to an inert gas atmosphere
A dehydrogenation treatment for promoting phase transformation by forcibly releasing hydrogen from the RTBM-based alloy raw material by maintaining the temperature at a predetermined temperature in the range of 00 to 900 ° C., followed by cooling,
It is a pattern diagram of the manufacturing method of rare earth magnet powder which is then ground.

As can be seen from a comparison between FIGS. 1 and 2 which are pattern diagrams of the method for producing a rare earth magnet powder of the present invention and FIG. 3 which is a pattern diagram of a conventional method for producing a rare earth magnet powder, the rare earth of the present invention is understood. The major difference between the method for producing the magnet powder and the conventional method for producing the rare earth magnet powder is that the RTBM-based alloy raw material is cooled from room temperature to 10% in an inert gas atmosphere or a vacuum atmosphere of 1 Torr or less.
After the temperature is raised to a predetermined temperature in the range of more than 00 ° C. and 1200 ° C. or less and kept at the same temperature,
Hydrogen is introduced at a predetermined temperature within the range of not more than 1000 ° C. and converted into a hydrogen atmosphere.
A hydrogen storage pretreatment is performed in which the RTBM-based alloy raw material is held in the following hydrogen atmosphere or the temperature is reduced to a predetermined temperature within a range of 800 to 1000 ° C. in the hydrogen atmosphere without holding. It is to apply. The method for producing a rare earth magnet powder of the present invention can further improve the residual magnetic flux density (Br) and further reduce the temperature coefficient of coercive force as compared with the conventional hydrogen storage treatment and dehydrogenation treatment. It is considered that in the method for producing a rare earth magnet powder to be subjected to the above, a hydrogen storage pretreatment is further added.

In the method for producing a rare earth magnet powder according to the present invention, the RTBM-based alloy raw material is heated from room temperature to 100 ° C. in an inert gas atmosphere or a vacuum atmosphere of 1 Torr or less.
The reason for raising the temperature to a predetermined temperature in the range of more than 0 ° C and 1200 ° C or less and maintaining the same temperature is that at 1000 ° C or less, the improvement of the residual magnetic flux density is insufficient, and the temperature coefficient of the coercive force is sufficiently increased. On the other hand, when the temperature is kept at more than 1200 ° C., the RTB-
This is because the M-based alloy raw material dissolves, which is not preferable. A more preferred temperature range for this step is 1
It is a predetermined temperature in the range of 030 to 1100 ° C.

Further, hydrogen is introduced at a predetermined temperature in the range of more than 1000 ° C. and 1,200 ° C. or less to convert it into a hydrogen atmosphere. The reason why the temperature is lowered in a hydrogen atmosphere without holding or holding the BM-based alloy raw material is that it is not preferable that the magnetic properties are not sufficiently improved by performing the hydrogen storage pretreatment at 1000 ° C. or lower. If the temperature is kept over 1200 ° C, RT
This is because the -BM-based alloy raw material is not preferable because it is melted. A more preferable temperature range in this step is a predetermined temperature in the range of 1030 to 1100 ° C.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION A high-frequency vacuum melting furnace is used to melt and cast in an alumina crucible to produce ingots A to K having the component compositions shown in Table 1, and further to the ingots A to K If necessary, in an Ar gas atmosphere, temperature: 1120 ° C., 2
A homogenization treatment under the condition of holding for 0 hour was performed. The ingots subjected to the homogenization treatment among the ingots A to K are marked with *.

[0014]

[Table 1] (The ingots marked with * indicate that they have been homogenized.)

The ingots A to K of the RTBM-based alloy raw materials shown in Table 1 are crushed into blocks having a size of 20 mm square or less, and hydrogen storage pretreatment, hydrogen storage The dehydrogenation treatment was performed, then the mixture was forcibly cooled to room temperature with Ar gas, and pulverized to 400 μm or less to produce rare earth magnet powders, whereby the present invention methods 1 to 16 and conventional methods 1 to 16 were carried out. Inventive Methods 1-16 and Conventional Method 1
3% by weight of an epoxy resin is added to each of the rare earth magnet powders obtained in Steps 16 to 16, and the mixture is kneaded, and compression molded in a magnetic field of 20 kOe to produce a green compact. Heat cured for a time to make a bonded magnet,
The residual magnetic flux density (Br) of the obtained bonded magnet and 20
The temperature coefficient β of the coercive force at 100 ° C. was measured, and the results are shown in Tables 2 to 4.

[0016]

[Table 2]

[0017]

[Table 3]

[0018]

[Table 4]

From the results shown in Tables 1 and 2, a bonded magnet produced from the rare earth magnet powder obtained by the method 1 of the present invention obtained by subjecting the ingot A of Table 1 to a pretreatment for hydrogen storage, a hydrogen storage treatment and a dehydrogenation treatment. Flux density (Br) and 20-1
The temperature coefficient β of the coercive force at 00 ° C. is larger than that of Br of the bonded magnet made of the rare earth magnet powder obtained by the conventional method 1 in which the ingot A is subjected to the hydrogen absorbing treatment and the dehydrogenating treatment without the hydrogen absorbing pretreatment. Temperature coefficient of coercive force β
It can be seen from the fact that the absolute value of R.sub.2 is small, so that it is possible to provide a rare earth magnet powder which is more excellent than the conventional one.

Similarly, from the results shown in Tables 1 to 4, the ingots B to K in Table 1 were obtained by the present invention methods 2 to 16 in which the hydrogen storage pretreatment, the hydrogen storage processing, and the dehydrogenation processing were performed, respectively. Of bonded magnet made of rare earth magnet powder
And the temperature coefficient β of the coercive force at 20 to 100 ° C. was obtained from rare earth magnet powders obtained by conventional methods 2 to 16 in which ingots B to K were subjected to hydrogen storage treatment and dehydrogenation treatment without hydrogen storage pretreatment. It is superior to Br of the bonded magnet obtained, and the absolute value of the temperature coefficient β of the coercive force is small, so that it can be seen that a rare earth magnet powder which is more excellent than the conventional one can be provided.

[0021]

As described above, according to the present invention, a rare earth magnet powder which is superior to the conventional one can be produced, and an industrially superior effect can be obtained.

[Brief description of the drawings]

FIG. 1 is a pattern diagram showing the relationship between atmosphere, temperature and time in the method for producing a rare earth magnet powder of the present invention.

FIG. 2 is a pattern diagram showing the relationship between atmosphere, temperature and time in the method for producing a rare earth magnet powder of the present invention.

FIG. 3 is a pattern diagram showing the relationship between atmosphere, temperature, and time in a conventional method for producing a rare earth magnet powder.

Claims (5)

[Claims] 1. A rare earth element containing Y (hereinafter referred to as R)
And Fe or a component in which a part of Fe is replaced with Co (hereinafter, referred to as T), B as a main component, and Si, G
a, Zr, Nb, Mo, Hf, Ta, W, Al, Ti,
One or more of V (hereinafter, referred to as M):
An alloy material containing 001 to 5.0 atomic% (hereinafter, this alloy material is referred to as an RTBM-based alloy material) is heated from room temperature to 1000 ° C. in an inert gas atmosphere or a vacuum atmosphere of 1 Torr or less. Temperature and rise to a predetermined temperature in a range of 1200 ° C. or less, and after maintaining the same temperature, hydrogen is introduced at the same temperature to be converted into a hydrogen atmosphere, and subsequently in the hydrogen atmosphere, the temperature is kept within the same temperature range. After holding at 800-1
By performing a hydrogen storage pretreatment for lowering the temperature to a predetermined temperature in the range of 000 ° C., and then maintaining the temperature in the hydrogen atmosphere at a predetermined temperature in the range of 800 to 1000 ° C., the R-T-B
Performing a hydrogen storage process of absorbing hydrogen in the M-based alloy material to promote phase transformation, and further converting the atmosphere into a vacuum atmosphere of 1 Torr or less or an inert gas atmosphere of hydrogen partial pressure: 1 Torr or less;
After maintaining a predetermined temperature in the range of 500 to 900 ° C. in this atmosphere to forcibly release hydrogen from the RTBM-based alloy raw material and perform a dehydrogenation treatment for promoting phase transformation, A method for producing a rare earth magnet powder having excellent magnetic properties, comprising cooling and then pulverizing. 2. An RTBM-based alloy raw material is heated from room temperature to a predetermined temperature in a range from more than 1000 ° C. to 1200 ° C. in an inert gas atmosphere or a vacuum atmosphere of 1 Torr or less. After maintaining at the same temperature, hydrogen is introduced at the same temperature to convert it into a hydrogen atmosphere, and immediately subjected to a hydrogen storage pretreatment in which the temperature is lowered to a predetermined temperature in the range of 800 to 1000 ° C. in the hydrogen atmosphere; By maintaining a predetermined temperature in the range of 800 to 1000 ° C. in this hydrogen atmosphere, the RTB is maintained.
Performing a hydrogen storage process of absorbing hydrogen in the M-based alloy material to promote phase transformation, and further converting the atmosphere into a vacuum atmosphere of 1 Torr or less or an inert gas atmosphere of hydrogen partial pressure: 1 Torr or less;
After maintaining a predetermined temperature in the range of 500 to 900 ° C. in this atmosphere, hydrogen is forcibly released from the RTBM-based alloy raw material to perform a dehydrogenation treatment for promoting phase transformation. A method of producing rare earth magnet powder having excellent magnetic properties, comprising cooling, and then pulverizing. 3. An RTBM-based alloy raw material is heated from room temperature to a predetermined temperature in a range from more than 1000 ° C. to 1200 ° C. in an inert gas atmosphere or a vacuum atmosphere of 1 Torr or less. After holding, hydrogen was introduced at the same temperature to convert the atmosphere to a hydrogen atmosphere of 0.5 to 10 atm.
Preliminary hydrogen storage treatment for lowering the temperature to a predetermined temperature within the range of 1000 ° C. is performed.
By holding at a predetermined temperature in the range of ~ 1000 ° C, the R-TBM-based alloy raw material is subjected to a hydrogen storage treatment for absorbing hydrogen to promote phase transformation, and further, the atmosphere is set to 1 Torr or less. Convert to a vacuum atmosphere or an inert gas atmosphere of hydrogen partial pressure: 1 Torr or less,
After maintaining a predetermined temperature in the range of 500 to 900 ° C. in this atmosphere to forcibly release hydrogen from the RTBM-based alloy raw material and perform a dehydrogenation treatment for promoting phase transformation, A method for producing a rare earth magnet powder having excellent magnetic properties, comprising cooling and then pulverizing. 4. An RTBM-based alloy raw material is heated from room temperature to a predetermined temperature in a range from more than 1000 ° C. to 1200 ° C. in an inert gas atmosphere or a vacuum atmosphere of 1 Torr or less. After the holding, hydrogen is introduced at the same temperature to convert the atmosphere into a hydrogen atmosphere of 0.5 to 10 atm. Immediately in the hydrogen atmosphere, a hydrogen storage pretreatment for lowering the temperature to a predetermined temperature within a range of 800 to 1000 ° C. Then, in this hydrogen atmosphere of 0.5 to 10 atm.
By holding at a predetermined temperature in the range of ~ 1000 ° C, the R-TBM-based alloy raw material is subjected to a hydrogen storage treatment for absorbing hydrogen to promote phase transformation, and further, the atmosphere is set to 1 Torr or less. Convert to a vacuum atmosphere or an inert gas atmosphere of hydrogen partial pressure: 1 Torr or less,
After maintaining a predetermined temperature in the range of 500 to 900 ° C. in this atmosphere, hydrogen is forcibly released from the RTBM-based alloy raw material to perform a dehydrogenation treatment for promoting phase transformation. A method of producing rare earth magnet powder having excellent magnetic properties, comprising cooling, and then pulverizing. 5. The raw material of the RTBM-based alloy is Ar
5. The excellent magnetic material according to claim 1, wherein the raw material is an RTBM-based alloy material that has been homogenized in a gas atmosphere at a temperature of 600 to 1200 [deg.] C. A method for producing a rare earth magnet powder having characteristics.