JPS60165702A - Manufacture of permanent magnet - Google Patents

Abstract

PURPOSE:To obtain a permanent magnet which has improved Hc and shows less fluctuation by applying the predetermined heat processing which is carried out after the sequential aging through multistage or continuous temperature rise from a low temperature side to an allow having the predetermined composition of the rare earth metal R-Fe-B system. CONSTITUTION:In an alloy R(Fe1-xBx)z, R is a kind of the rare earth element or a combination of two kinds of such elements, (x) and (z) are selected in the following range, 0.02<=x<=0.15, 4.5<=A<=7.5, or a part of Fe is replaced with Co, Mn, Ni or a part of B with Si, Ge. For example, an alloy Nd(Fe0.8Co0.1B0.1)5.4 is dissolved by arc and an ingot is formed. It is then converted to fine powder with graian size of 3-5mum (F.S.S.S.) under the N2 ambient. The powder is presssurized for molding in the direction at the right angle to the direction of field under the Ar ambient. Temperature is raised in multistages under the Ar ambient from room temperature 500 deg.C up to 800-1,000 deg.C for the ageing. Thereafter, the mold is cooled rapidly under the Ar ambient. According to this constitution, a permanent magnet which has improved Hc and shows less fluctuation can be obtained.

Description

Detailed Description of the Invention The present invention mainly focuses on rare earth metals (hereinafter abbreviated as R) and Fe.
The present invention relates to a method for producing an intermetallic compound permanent magnet material comprising: F<-Fe improved by B addition
- This invention relates to a method for manufacturing a B-based permanent magnet material.

As already known, R-Fe combination! , for example R2
Fe is a permanent magnet material that has higher saturation magnetization than R-Co alloy, does not contain expensive CO, and has high potential as a permanent magnet material. However, the necessary Ha as a permanent magnet material could not be obtained, and the device remained in use 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, Cro
at.

Journal of Applied PhVStO3
52 (3) M arch 1981.2509 “lyl
agneNc properties of mel
t-5punPr-Fealloys"〉
Furthermore, N., C., and Koon et al.
The e-B alloy is ultra-quenched at 600-800℃km.

A high coercive force is achieved through aging crystallization. (N, C, Koon et al Ar1I)1. P
hys.

Letter 39 (10) 15 (1981)
840 “Ma(InetiCProperNeso
fAmorphous and Crystaliz
edF 0o, s2 s, , 8) o, q ” bCO
5' ``O, oS'' ``Machibun Sho 58-123853 Publication) However,'' the production method requires a mixed state of crystalline and amorphous materials, and the obtained monthly yield is generally in the form of powder or thin powder. Limited to obi.

Therefore, when using it as a permanent magnet material, it is necessary to bulk it by compression molding or the like. or,
Powder obtained by ultra-quenching is isotropic and has a poor square shape, making it difficult to magnetize and causing many problems in practical use.

On the other hand, for body use, crystalline Nd-Fe-B was used, and high properties were obtained by molding and sintering in a magnetic field to create anisotropy. (
29th 3MConf, 1983 booklet P
110, 5essionEB, EB-1”New
Material for Permanent Mag
nets on a base of
e") The obtained magnetic properties are 35 to 40 MGOe, the highest among rare earth magnets. However, the Curie point of water-based magnets is around 300°C, and there was a problem with thermal stability. In other words, when heating water-based magnets, In this case, heat causes reversal of magnetization and tends to cause demagnetization.One way to improve this drawback is to increase 1-1c.Already known heat treatment methods is 6 after sintering
This means that it is heated to around 00°C. (29th 3
(M Conf, announced) However, there is a limit to the amount of Hc that can be obtained with this instant heat treatment method;
There was also a lot of variation in HC.

The present invention aims to improve the pHc of these R-Fe-B alloys.

This was done for the purpose of reducing the variation in Ha.The heat treatment is performed in the temperature range from room temperature to 500℃, aging is sequentially applied in multiple stages to the high temperature side, and after the aging is completed in the temperature range of 800 to 100℃, it is rapidly cooled. The above objectives have been achieved.

The heat treatment of the present invention is performed by multi-stage aging or continuous heating from the low temperature side. It is appropriate to select a temperature at which aging starts from room temperature to 500°C, and aging starts at a temperature of 500°C or higher.
It is not possible to improve zHc and reduce dHc variation. When the quenching start temperature is 800°C or less, the increase in HC is not significant, and when it is 1000°C or higher, the decrease in Hc is significant.

Permanent magnets to which the present invention can be applied are generally manufactured by the steps of melting into an ingot, crushing, forming in a magnetic field, sintering, and heat treatment. The melting is carried out in a conventional manner in Ar or vacuum. It is also possible to use ferroboron for B. Grinding can be roughly divided into coarse grinding and fine grinding, and coarse grinding is done by stamp mills, show crushers, brown mills, and disc mills, and fine grinding is done by diene mills and vibration mills.

This is done using a 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 μra (F.

S, S, S, > is desirable. Molding in a magnetic field improves orientation,
This is necessary for anisotropy, and generally vertical magnetic field shaping (the direction of pressure and the direction of magnetic field application are parallel) and transverse magnetic field shaping (the direction of pressure and the direction of magnetic field application are perpendicular) are used. Horizontal magnetic field forming has a better degree of orientation than vertical magnetic field forming. Sintering is Ar, H
It is carried out in an inert gas such as e or in vacuum. Furthermore, N
Sintering in two gases is also possible. Rapid cooling is preferable for cooling after sintering.

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

Example 1 N d (F eo, 9B0.1)5. An alloy having the following composition was produced by arc melting. The obtained ingot was pulverized using a stamp mill and a disc mill.

The grinding medium is N2 gas, and the grinding particle size is 3.5 μm (F
, S, S, S,). 15k of the resulting finely ground powder
Transverse magnetic field shaping was performed in a magnetic field of Os. Molding pressure is 2 tons
/ am'. The obtained molded body was heated in an Ar atmosphere for 2
Sintered in stages. The first stage is 1180℃ x 1 hr, the second stage is 1 hour
The temperature was 100°C x Ihr, and after sintering, it was rapidly cooled in an Ar gas flow. The magnetic properties after quenching were as follows.

B "~12100G BHO~ 88000s Me) lc~ 93000e (3 days) maX ~34.5M G Oe 4 to this magnet
00℃ x 1hr + 500℃ x 1hr + 600℃
x1hr 700℃x1hr +800℃×Yuzur +
When subjected to multi-stage aging at 900° C. for 1 hour and rapidly cooled, the following magnetic properties were obtained.

Br ~12080G BH (j ~95000e z@O~133000e (B H) max ~35.IM G 0s600℃
Compared to the aging of ×Yuzu, multi-stage aging is more effective in obtaining high jHc, the square shape is also improved, and high (B H)
max is obtained.

Example 2 An alloy having the composition Pr (Feo, q Bo, 1) 5 was melted, crushed, and molded in a magnetic field in the same manner as in Example 1.

Sintered. Table 1 shows the results of applying various types of aging to this magnet. The contents of the statute of limitations in Table 1 are shown in Table 2.

Example 3 N de, b Pro, 4 (F eo, q B11
．． 01. S! An alloy having a composition of 0.04)5 was melted and pulverized in the same manner as in Example 1.

Molded in a magnetic field. Sintering is 1100℃ x Yuzu + 1120℃
Two-stage sintering was performed for 1 hr, followed by rapid cooling in an Ar gas flow.

After quenching, aging was performed at 600°C x Ihr, and the following magnetic properties were obtained.

Br-11500G BHC~70000e Engineering HC~85000s (BH) maX"□31.5M Gos.

Further, it was heated from room temperature to 1000°C at a rate of 1.3°C/min, held for 1 hour, and then rapidly cooled in an Ar gas flow. The obtained magnetic properties were: B'~11480G BHc~950008 pHC~145000e (3@) maX ~32.IMGOe.

7- Example 4 N d (F eo, B COo, 1 so, 1>5,
The alloy was melted, crushed, formed in a magnetic field, and sintered in the same manner as in Example 1. As a result of aging at 600° C. for 1 hr after sintering, the following magnetic properties were obtained.

Br-10750G BHC" 87000e zHO~99000e (BH) max ~27. IMGOe further 500℃
Multi-stage aging was performed. That is, 500℃ x 1hr
+600℃x1hr +700℃x1t+r 1800
℃XIhr +900℃×Yuzur + 1000'CX
After aging for 1 hr, it was rapidly cooled in Ar. The obtained magnetic properties were B r ~10820G &HC ~95000ez)-1c ~142000e (BH) maX ~28.2M G Os.

8-

Claims (1)

[Claims] R(Fe1.B, ), (where R: one type or a combination of two or more rare earth elements, 0.02≦X≦0.15. 4.5≦Δ≦7.5 , however, part of Fe is Co, M
n. In N1, a part of B can be replaced with S:, ae. ) The alloy with the composition is melted, pulverized, and formed into a vA lift. In a method for manufacturing rare earth magnets that involves sintering and heat treatment, heat treatment is started from room temperature to 500°C, and aging is added by sequentially increasing the temperature in multiple stages or continuously to a high temperature range of 800 to 100°C.
A method for producing a permanent magnet characterized by rapid cooling after aging in a temperature range of 0.000°C.