JPS59106106A - Manufacture of permanent magnet - Google Patents

Abstract

PURPOSE:To obtain a rare-earth element-cobalt permanent magnet having good sintering property of the compact, high magnetic flux density and superior maximum energy product by a method wherein a powder mixture of alloy powder having the R2Co17 type phase as a main phase and alloy powder having the RC05 type phase as a main phase is compacted in the magnetic field and then sintered. CONSTITUTION:A powder mixture of alloy powder having the R2Co17 type phase (where R represents one or more rare-earth element) as a main phase and alloy powder having the RC05 type phase as a main phase is compacted in the magnetic field and then sintered. The mixture ratio of said two kinds of alloy powders is preferably such that the alloy powder having the 1-5 type phase as a main phase is not higher than 50% in terms of wt%. If it exceeds 50%, the sintering property shows tendency to be lowered and magnetic characteristics of the permanent magnet are liable to be deteriorated. To improve magnetic characteristics of the permanent magnet, it is desirable to add Fe in the high composition ratio.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a method for producing a rare earth-cobalt permanent magnet, and more specifically, a magnetic alloy having good sinterability and, as a result, excellent magnetic properties. The present invention relates to a method of manufacturing a rare earth-cobalt permanent magnet.

[Technical background of the invention]

Conventionally, SmzCox type 7 (hereinafter referred to as
A permanent magnet (abbreviated as 2-17W) has been proposed, and as a method for manufacturing it, a magnetic alloy with a final composition containing at least Vi, an i or more rare earth element and cobalt is heated, for example, by high-frequency induction heating means. The magnetic alloy was prepared by the melting method used, and then the magnetic alloy was pulverized to a fine powder, the powder was molded in a '6f1 field, the resulting molded body was completely sintered, and then solution treatment, A manufacturing method that involves aging treatment is known (Japanese Unexamined Patent Publication No. 52-109191,
(See Japanese Patent Publication No. 55-15096, etc.).

[Problems with background technology]

Now, in this 2-17 type permanent magnet, in order to improve the magnetic properties of the magnet, as an aspect.

Copper as an element other than rare earth elements and cobalt.

Magnetic alloys containing iron, titanium, turconium, hafnium, niobium, nickel, manganese, etc. were used;
)max) and magnetic flux density (Br), it is necessary to increase the composition ratio of iron among other elements.

However, in the above-mentioned conventional manufacturing method, when the iron composition ratio in the magnetic alloy increases, the sinterability becomes extremely rapid when sintering the molded body obtained by the magnetic field forming method.
As a result, there is a drawback that a permanent magnet having a high (BH) max cannot be obtained.

Therefore, it has been desired to develop a method capable of producing a rare earth-cobalt permanent magnet having good sinterability and excellent magnetic properties.

[Purpose of the invention]

An object of the present invention is to provide a method for manufacturing a 2-17 type rare earth-cobalt permanent magnet that has a molded body with good sinterability, high magnetic flux density, and excellent maximum energy product.

[Summary of the invention]

In order to solve the above-mentioned problems, the present inventors have conducted extensive research on sintering methods for magnetic alloys, and have found that, even when sintering a molded body made only of alloy powder with a high FemK ratio,
Alloy powder with 2-17 type phase as the main phase and 1-5 type phase (RC
O5 type phase (abbreviation for O5 type phase) is mixed to form a molded body so that the two types of alloy powder consisting of alloy powder as the entire main phase have the desired final composition of a permanent magnet with high Fe composition, and then this is sintered. The sinterability is better when sintered, resulting in high Br and high (
The present invention was completed by discovering a new fact that a permanent magnet with BH)max can be obtained and utilizing this fact.

That is, the present invention provides a method for completely manufacturing a permanent magnet by molding an alloy powder containing at least one or more rare earth elements (R) and copal (Co) in a magnetic field, and then sintering the powder. All characteristics are that the alloy powder described in item 2 is a mixed powder formed by mixing an alloy powder having an R2C017 type phase as a main phase and an alloy powder having an RCo5 type phase as a main phase.

The difference between the method of the present invention and the conventional method is that the method of the present invention uses an alloy powder having all the 2-17 type phase as the main phase;
This method involves sintering a mixed powder with an alloy powder whose main phase is a mold phase, and the composition of the entire mixed powder only needs to be the same as the target composition of the resulting permanent magnet. The only difference is that the type of alloy powder itself is the same as the target composition of the obtained permanent magnet.

Therefore, the method of the present invention conforms to the conventional method in other respects.

In the method of the present invention, first Sm, Pr, Ce
.

Sc, Y, La, Nd, Pm, E
u, Gd, Dy + no + Er, Yb
, Lu, Tb, Tm 1 or more of rare earth elements such as 1 or 281 or more, cobalt, and other elements if necessary, and an alloy powder having a 2-17 type phase as the main phase, and 1- Two types of alloy powders having type 5 phase as the entire main phase are prepared. Here, the other elements are Fe
, Cu, IVln, Cr, Ni, etc., or more than 2 af elements, but in order to improve the magnetic properties of permanent magnets, T
It is desirable to add transition metals such as i, Zr, Hf, Nb, Ta, and W. Furthermore, in the present invention, 2-
The fact that the 17 type phase or 1-5 type phase is the main phase means that the other phases may be any phase, but the 2-17 type phase or 1-5 type phase is the main phase among the various phases that exist in the alloy composition. This means that type 5 has the highest abundance. Furthermore, if it is necessary to add other elements mentioned above, the elements should be added in 2-17
It may be contained in either or both of the alloy powder having the type phase as the main phase or the alloy powder having the 1-5 type phase as the main phase.

The mixing ratio of these two types of alloy powder is preferably 50% or less by weight of the alloy powder whose main phase is the 1-5 type phase in the mixed powder. If it exceeds 50%, the sinterability tends to decrease, and as a result, the magnetic f of the obtained permanent magnet decreases.
l' items are more likely to deteriorate.

In addition, in order to improve the magnetic properties of permanent magnets, Fe
It is desirable to add at a high composition ratio, but one misfire JVC
In a mixed powder composed of the above two types of alloy powder, when the Fe content exceeds 15% by weight, sintering properties that are better than conventional ones can be obtained.

In the method of the present invention. Next, the above-mentioned mixed powder is molded in a magnetic field according to a conventional method, and then the obtained molded body is sintered. The sintering temperature and sintering time are not particularly limited; It is preferable to sinter with 11M1l intermediate between the former and the latter having a higher melting point. At this time, since the low melting point alloy is partially melted, the sintered density of the sintered body increases, and as a result, excellent sinterability is obtained.

In the present invention, it is possible to produce permanent magnets even with only the above-mentioned treatments, but if desired, even more excellent results can be obtained by further performing solution treatment and aging treatment according to conventional methods. A permanent magnet with magnetic properties is obtained.

Incidentally, the method of the present invention applies to permanent magnets containing Fe, especially Fe-containing permanent magnets.
Although the method of the present invention is effective for manufacturing permanent magnets with a content exceeding 15N, the method of the present invention is not limited to this. Even with permanent magnets that do not contain Fe, it is difficult to obtain the desired magnetic It is obvious that it can be applied even when a permanent magnet with a custom-made structure cannot be obtained. 3゜ [Embodiments of the invention] Examples 1 to 6 The 2-17 type phase shown in Table 1 is used as the main phase. alloy powder,
1-5 type phase as the main phase at the mixing ratio shown in Table 2, and then mixed by applying a pressure of about 2 ton/i in a 15 koe 5'A. A permanent magnet was produced by making an anisotropically cast powder compact, sintering the obtained powder compact, and then subjecting it to an aging treatment.

In addition, the composition of the mixed powder (′i4
．． Ji%) is p as follows.

Example 1 -3m 26.6%, Cu 10%, F
e18.4%, Ti 1.6%, Co balance//2 ・-S+n 25.5%, Cu 8.2
%, Fe22.5%, Ti 1.8%, Co
Remaining tl 3 =-Sm 27.0%, Cu 8.2
%, Fe 17.0%, Mn 4.2%, T
i 0.8%, NbO, 8%, Co remaining tt 4 ・-3m 16.3%, Ce 8.9%
, (: u6.9%.

Fe 16.6%, Ni 4.4%I'l'11.3
%.

Co remaining // 5-8m 25.0% + Pr 3.0%, C
u1.0.0%, Fe16.5%, TiO
, 5%, Nb003, Co remaining Example 6 - Sm 26.5%, Cu 7.75
%, Fe24.8%, Ti 1.5%, C
In addition, the sintering conditions and aging treatment patterns are listed in Table 2. In the table, the number indicating f-turn (aging treatment) represents the following aging treatment. (850°C x 1 hr) +(750℃X
4hrs) + (650°C x 10hrs) 2-(85
0℃×5hrs)+(750℃×10hrs)+(
650℃×20hrs)3-(650℃×1hr)
+ (550°C x 2hrs) + (450°C x 4hrs) Comparative Examples 1 to Comparative f16 The same examples as above except that a single alloy powder having the same composition as the mixed powder of Examples 1 to 6 was used, and the powder was completely sintered. Permanent magnets were manufactured using the same method.

Note that the same alloy numbers in the comparative example and the example correspond to each other.

The sintering conditions and aging treatment patterns are also listed in Table 2.

Regarding the above permanent magnets, the sintered density and various magnetic properties, which are indicators of sinterability, are summarized in Table 2.

〔Effect of the invention〕

According to the method for manufacturing a permanent magnet of the present invention, good sinterability can be obtained in the sintering process without affecting the magnetic properties of the rare earth-cobalt permanent magnet. This is especially
It is effective in preventing the deterioration of sinterability that occurs when increasing the Fe content in the magnet composition.
When the amount exceeds 5%, this effect becomes even more pronounced.

Therefore, due to improved sinterability, it has excellent magnetic properties and is inexpensive*ii
Since an i permanent magnet can be obtained, the industrial value of the present invention is extremely large.

Claims (1)

[Claims] A method for manufacturing a permanent magnet by molding an alloy powder containing at least one or more rare earth elements (R) and copal (Co) in a magnetic field and then sintering the powder, A method for producing a permanent magnet, wherein the alloy powder is a mixed powder obtained by mixing an alloy powder having an R2C017 type phase as a main phase and an alloy powder having an RCo5 type phase as a main phase.