JPS60114538A - Production of permanent magnet alloy - Google Patents

Abstract

PURPOSE:To produce a permanent magnet alloy having an excellent magnetic characteristic at a low cost by mixing oxide of rare earth metals, metals such as Co, Fe and Cu or the oxide thereof, metal such as Si, etc. or the oxide thereof and reducing agent such as Ca, etc. and reducing the mixture composed thereof by heating. CONSTITUTION:Prescribed amts. of oxide of R (>=1 kind among rare earth metals such as Sm, Ce, Pr, etc.), metals such as Co, Fe and Cu or the oxide thereof, metal M (>=1 kind among Si, Ti, Zr, Mn, V, Nb, Cr, Mo, Hf) or the oxide thereof, etc. and a reducing agent of >=1 kind among Ca, CaH2 and Mg are mixed and the resulted mixture is heated in a temp. range of 1,100-1,300 deg.C, more preferably 1,150-1,200 deg.C in a reducing atmosphere to cause reduction diffusing reaction. The permanent magnet alloy which is expressed by R(Co1-x-y-z FexCuyMz)A (where 0.01<=x<=0.40, 0.02<=y<=0.25, 0.005<=z<=0.15, 6<=A<=8.5) and has an excellent magnetic characteristic is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a permanent magnet alloy comprising a Cu-substituted R2C017-based rare earth metal compound.

It is well known that rare earth cobalt intermetallic compounds form various RCO phases (hereinafter R represents a rare earth metal 1-) depending on the content of rare earth metals, but the one currently in practical use is the RCO5 phase. J5 and R2C017 series permanent magnets.

RCO5-based permanent magnets (for example, JP-A-46-6503, JP-A-46-6504, and JP-A-4G-650!i) and R2C017-based permanent magnets in terms of maximum energy product [(BH)max] remains.Mister U J3J
In particular, recently, those with a maximum energy product of 25 Mg0e or more have been developed, and their uses are expanding.

This R2C01? Permanent magnets of various compositions are known (for example, JP-A-50-1115998,
52-1150 (No. 10, No. 56-156734,
57-128905Q), especially R (Co
+ -x-y-zFe CuVMz) A (However, R: 1 of rare earth metals such as Sn+, Ce, Pr, etc.
+! Ti or a combination of two or more, M: Si, Ti,
One type or a combination of two or more selected from the group of Zr, M++, V, Nb, Clo, Mo, l-H l! , 0.01
≦x ≦0.40.0.02≦y≦0.25.0.0
05≦7 ≦0.15.6≦A≦8.5) Permanent magnet (equity [1f) that depends on the expressed composition 55-5010
(Refer to Publication No. 0) has high performance (in the laboratory, 30 M GO
It is known that the maximum L energy can be obtained.

The method for producing such an R2Co17-based permanent magnet alloy is as follows: pure metals containing alloy components such as rare earth metals, Co, and Fe are made into rough stones, and then VJ molded into a C mold that is subjected to high frequency melting. Generally, the alloy ingot 1 is subjected to crushing, forming in a magnetic field, sintering, solution treatment, and aging treatment.

However, rare earths and similar metals generally have low prices, so the above-mentioned melting method requires high raw materials, which is a major factor in increasing manufacturing costs.

Therefore, in order to improve the above-mentioned drawbacks of the dissolution method, an inexpensive (
C
A direct reduction diffusion method has been proposed in which 01Fe and other metal components are alloyed by diffusion reaction (for example,
No. 9-7296, No. 53-16798, No. 55-30
575 and 55-27602).

However, the conventional direct reduction diffusion method is
As described in Publication No. 102271, one CO
Regarding binary permanent magnets such as B series, magnetic properties equivalent to those produced by high frequency melting method can be obtained, but C
The u-substituted R2C017 permanent magnet J3 has problems such as inferior magnetic properties compared to those made by high-frequency melting.

An object of the present invention is to solve the problems of the prior art described above, and to provide a CLI replacement type R2GO+ which is low cost and has excellent magnetic properties.
It is an object of the present invention to provide a manufacturing method capable of obtaining a 7-series permanent magnet.

The method for producing a permanent magnet alloy of the present invention is R(C017'x
-y-zFe CuyMz > A (However, R: Sm
, one kind or a combination of two or more kinds of rare earth metals such as Ce, Pr, etc., M: Si, li, Zr, Mn,
VSNb, Or, Mo, l-1117) combination of one or more types selected from the group, 0.01≦X≦0.40
．． 0.02≦V≦0.25.0.005≦2≦0.1
5.6≦A≦8.5) In the method for producing a permanent magnet alloy having a composition represented by or these oxides and c'a, c
One or more reducing agents selected from aH2 and Mil are mixed, and the resulting mixture is heated at a temperature of 1100 to 1300°C in a reducing atmosphere. It is characterized by heating in range C to carry out a reduction-diffusion reaction.

The details of the present invention will be explained below by taking as an example the case of manufacturing a CI replacement type 5II12C017 permanent magnet.

"In the present invention, rare earth oxides (for example, 5II12
03) and metals such as Fe, Co, and Cu or their acid agents (eg, Ca) are weighed out in predetermined amounts, and placed in a known mixer such as a V-type mixer and thoroughly stirred and mixed. Next, the obtained l [mixture was put into a reaction vessel, and the reducing gas (
For example, in a hydrogen gas atmosphere, the material is heated in a temperature range of 1,100 to 1,300° C. to carry out a reduction-diffusion reaction. The reduction-diffusion reaction proceeded smoothly, resulting in Iζζ association and rare earth oxide (31
11203,) and M oxides, e.g. Zr 02, are reduced by reducing agents (Ca, M(+, CaH2)k-, Cu, Co, FO are reduced by their respective oxides e.g. C
In the case of u o, Co 203, α-Fe203, R
It is reduced by 2 gases. Then, they are alloyed by interdiffusion (a woolly-shaped reaction product is formed). This reaction is detailed as follows.

Figure 1 shows the reaction process of Ca, Sm 203, l2e,
A differential thermal analyzer (DTA) using CO and Cu
) is the result of the investigation. F(!, GO, OJ, biCL
When one or more of I is used as an oxide and -C is used, by holding it at 400-600°C in 12, both of them are reduced by R2 and each becomes l according to the following formula. :e, CoJ3 and Cu are produced.

Fe 203 +382-'>3H20+FeCO2O
3+31-+2→31-(20+(:, .

CLI O+H2-ICU-1-1120 Therefore,
In FIG. 1, metal powder is used as the luminous material other than Sm2O3 in order to more clearly investigate the reaction situation of direct reduction and diffusion. An endothermic peak corresponding to the melting point of Ca, as shown by a in the figure, was observed near 800°C, and Ca in the liquid phase reached 5 liters.
Reduce l1203<sm 203-1-3 Ca
-128pl +3 Ca) Possible fever peak b
is observed between 830 and 900°C. The thus-reduced 3m and Fe, Go, and CIJ mutually diffuse to form an alloy of 5lll-co-Fe-Cu with a slight endothermic reaction C at approximately 900°C or above. It can be seen that the diffusion reaction progresses.

In addition, in Figure 1', as shown in d and in the figure, Ca
A slight exothermic reaction is observed below the melting point of , but this reaction is due to the formation of a low melting point alloy between 7 parts of Cu and Ca, and these peaks are
Co5L1tu mouth On 0fBinaryΔ110y
1, which is in good agreement with the result of the phase diagram of the a-Cu binary alloy described in S.
However, if Ca and Cul are added in a range of 1.1 to 1.5 times the stoichiometric composition, By doing so, the reduction in the coercive force can be effectively prevented.

Furthermore, as is clear from Fig. 1, the diffusion reaction will proceed at a temperature of 1000°C or higher;
(℃ or higher). tJ that is Sm2O3
Since the melting point of 3+11 (metal) produced from
, Cu). On the other hand, the heating temperature is 11
At temperatures above 00℃, the melting point of 3m is sufficiently higher than that of qsll.
l becomes a liquid phase and wets the surface of other metal particles,
The diffusion reaction progresses satisfactorily.

However, even if the heating temperature is too high, there is almost no change in the progress of the diffusion reaction.
A temperature of 250'C or lower) is sufficient. It is appropriate that the retention time for I to carry out the reduction-diffusion reaction is in the range of 1 to 511 hours.

Next, in the present invention, -[CaO(M(]
O) Surplus Ca (Mal > Ca (OH2) (M
(1(OH)2), followed by acid washing to forcibly dissolve and remove the remaining Ca-Cu alloy and their oxides, and washing with water to remove the acid. The reaction product after washing with water is dried in vacuum and then pulverized to an average particle size of several μm or less using a known pulverizer such as Diene 1-mill to obtain 1n alloy powder.

By using this alloy powder, it is possible to obtain a Cu-replacement type R2Co 1 type permanent magnet, which has magnetic properties equivalent to or greater than those obtained by melting and casting through normal processes. It will be done. For example, the above alloy powder is filled into a mold and heated in a magnetic field of 5 to 20 KOc at 2 to 10 tO1l/Cl.
Compression molding is performed by applying a pressure of 112 mm, and the resulting molded body is A.
11 in an inert gas or hydrogen gas atmosphere such as r, He, XcSKr, or in vacuum (10 to 10 torr)
The sintered body is sintered at a temperature of 50 to 125°C (1'c).Then, the sintered body is held at a temperature of 1100 to 1200°C for 0.5 to 4 hours to perform solution treatment, and then cooled with oil or water. It was poured into a medium and rapidly cooled, and then cooled to 0 at a temperature of C800-950℃.
．． 4 at a rate of 0.3-3'C/min after holding for 5-4 hours.
Aging treatment is performed by cooling Mlt to 00°C and holding there for 0.5 to 3 hours.

Hereinafter, comparative examples and examples of the present invention will be explained.J'7) However, the scope of the present invention is not limited by these examples.

Comparative Example 3111130.2g, C0251,0(1, F C7
Weigh (1,0 mm), Cu4 (1, (Ig, Z r9.0 g), put them into the arc melting power,
After melting to 1112 Torr in an Ar gas atmosphere, then casting into a mold and crushing the IC9J5f ingot, the composition of the base metal (481) was found to be tJ<i・, as shown in Table 1. A magnet alloy corresponding to the target composition was obtained.

(The unit is small m%) The above alloy powder was milled in a ball mill to obtain an average particle diameter of II, 7.
Finely ground J)) into flm particles. 10KOO of finely ground powder
Approximately 21on/G I in the magnetic field (horizontal Wti 'M)
The molded product was molded at a pressure of t-7' L/s at 112°C and heated at 1150 to 1200°C in a 112 gas atmosphere.
x After sintering under the conditions of 1.5 h, 1150 to 1190
1 in °C! Solution treatment was carried out while maintaining the i l+ image.

Ff from 1300 to 900'C after III conversion treatment? Wet it and hold it at that temperature, then heat it at a rate of 1'C/n+in to 400°C and cool it to C111.
It was kept and subjected to aging treatment.

The magnetic properties of the obtained permanent magnet G are such that Br is 10,1ioO
G, ■1-1c is 70500 e, < B l-1)
InaX is 27.3M G OeC
.

Example 3m 203 151. H, Co 203 353,2
gr, “e 203 100. Igr, Z C9, Og
r, CIJ38. ! +gr, Ca8B, and Ogr were each weighed and dry mixed in a V-type mixer for 30 minutes. Note that Ccz13 and Ca are 1.0% of the target chemical composition.
Three times the amount was added. The obtained ff2 compound was heated at a temperature of 1170°C in an H2 gas atmosphere for 311 hours to carry out a C reduction diffusion reaction.

Next, the resulting cake was washed by repeatedly throwing it into water for 2 hours. After washing, pickle with Pi-12 to 5 range C hydrochloric acid to dissolve and remove the d-type residue, then wash with water until the pH becomes 6.5 to 7, and then in a vacuum at 80°C.
It was dried under the conditions of (°CX12+). A compositional analysis of the obtained alloy revealed that as shown in Table 2, the magnetic alloy corresponding to the target composition was 1. H1′, 7. :.

Table 2 (unit: small fQ%) The above alloy powder was subjected to the same process as in the comparative example (IC pulverization, molding in a magnetic field, sintering J3 and heat treatment to form a permanent magnet of 7.2
61c F, l
Been

[Brief explanation of drawings]

Figure 1 shows 5I11203-Fe -Co -Cu -C
: is a diagram showing the results of differential thermal analysis of the reduction-diffusion reaction by a.

Claims (1)

[Claims] 1, R(Co i -x-V-IFX CuVMZ
) A NIJL/, R: 5III, Ce, Pr, etc., or a combination of two or more rare earth metals t! , M:Si,
-ri, Zr, Mn, V, Nii, Or, Mo,)
-1 type or combination of two or more types selected from the group of 1f, 0
．． 01≦X≦0.40.0.02≦y≦0.25.0.
005≦l≦0.15.6≦A≦8.5), in which the rare earth metal oxide, the GO, FO, CLI metal, or these Oxide M metal or these oxides J3
and one or more reducing agents selected from Cy a, Cal-12, and Mil, and the resulting mixture is reduced (in an atmosphere at a temperature of 1100 to 1300°C). 2. A method for producing a permanent magnet alloy, characterized by heating in a temperature range of 0 to 1200°C to cause a reduction diffusion reaction. A method for producing a permanent magnet alloy according to claim 1.