JPS60228649A - Manufacture of permanent magnet alloy - Google Patents

Abstract

PURPOSE:To improve the magnetic characteristics by mixing Al-Ni-Co-Fe alloy powder having a specified particle size distribution with powders of the constituent elements, molding the mixture, and sintering it in vacuum or a nonoxidizing atmosphere. CONSTITUTION:Al-Ni-Co-Fe or Al-Ni-Fe alloy powder whose principal part is particles having <=200 mesh particle size is mixed with powders of the constituent elements such as Al and Ni having <=200 mesh or powder of an alloy thereof, and the mixture is press-molded after adding a binder. The molded body is heated at a proper temp. to remove the binder, and it is sintered in vacuum or a nonoxidizing atmosphere to obtain an Al-Ni-Co-Fe or Al-Ni-Fe type sintered magnet alloy. Since powders having <=200 mesh are used as starting materials, reduction in sintering density is prevented, and reduction in Br as one of magnetic characteristics can be also prevented by the uniform diffusion of the constituent atoms during sintering. Accordingly, the magnetic characteristics of the sintered magnet alloy are improved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an AL-Ni-Co-Fe (alcony) system.

At-Ni-Fg (Alco) series (hereinafter referred to as this alloy).

related to improvements in sintered magnet alloys.

Typical standards for this type of alloy are Alnico 1.2, 3, 4, 5, 6, 7.8, etc., and they are generally manufactured by the melt casting method, but especially for small items. Powder metallurgy manufacturing methods are sometimes applied to products with complex shapes.

The method of manufacturing this metal is by powder metallurgy (sintering method).

(1) A method in which component element powders are mixed to have a predetermined chemical composition, and then molded and sintered. (2) A method in which an alloy powder having a predetermined chemical composition is molded and sintered.

(6) For oxidation prevention), for example, Ai is
This is used in the form of a mother alloy powder, which is then mixed with other component element powders.

There is a method of mixing, then shaping and sintering. .

Among these, method (6) is generally used to prevent deterioration of magnetic properties due to oxidation.

Sintering is performed in vacuum or in B2 to prevent oxidation as well.

In addition, for the purpose of improving the magnetic properties, especially the residual magnetic flux density Br, by bringing the sintered density of the alnico thread magnet alloy as close to the theoretical density as possible, for example, Like, S.

In some cases, a method of adding trace amounts of B, P, etc. is adopted.

The advantage of applying the sintering method to alnico magnets is that the process from melting to solution treatment is an extremely simple process of powder mixing, molding, and sintering, and there is no need for a runner. A major advantage is that the yield is improved.

However, on the other hand, in magnets produced by sintering methods, there is generally a difference between sintering density and magnetic properties.

There is a close correlation with the increase in porosity of the sintered body.

Therefore, Br decreases almost proportionally. Also, S, B,.

The addition of P improved the sintered density.

However, the addition of these non-magnetic elements also improves magnetic properties.

This is due to the following factors. Furthermore, the above raw materials (1) and (6).

When obtaining sintered magnets from powder, tubes of powder grain size.

Burying is important and when using 1-grain powder.

In this case, interdiffusion between elements is inhibited during sintering.

As a result, the obtained magnet contains component fluctuations or segregation, which deteriorates the magnetic properties. Also%(
When using method 2), the raw material powder is obtained by preparing an ingot in advance and mechanically crushing it, or by water atomization or gas atomization from the molten metal, but evaporation, volatilization, oxidation, etc. may be accompanied by component fluctuations due to

However, since a method is adopted in which the component composition is adjusted by using the necessary component elements or alloys before molding, the magnetic properties may deteriorate depending on the powder particle size, as in cases (1) and (5) above. This will cause

There is.

Therefore, the inventors developed an alloy powder for magnet alloys.

As a result of various studies, we found the following.

First, we cast the raw materials to obtain the required components.

First, using the cooled alloy as a starting material, it is sequentially crushed using a stamp mill, a Joe crusher, and a ball mill to form at least 100 meshes, io.

Powders of ~200 mesh and less than 200 mesh were collected by classification. After these powders were mixed in various ratios, granulation was performed again using a wax binder as necessary, and sintering was performed in a non-oxidizing atmosphere. Next, after heat treatment, the magnetic properties were measured and the result was 2.
It was possible to obtain high characteristics in a magnet obtained from a raw material containing about 50 or more pieces of powder with a particle size of 0.00 METSH or less. Furthermore, the runner part coming out of the cast magnetic 6 stone was crushed under the same conditions and 1% was added to it for component adjustment, including Fg, FtTi, and Fa.
-50AL.

Similarly, alloy powders such as +100' and +20
0~.

=100 and -200, and these were classified into the above-mentioned hot water.

-520 even when mixed with ground powder
Magnet odor obtained by using 50 degrees or more of powder of 0.

We were able to obtain excellent magnetic properties. In addition, one bottle.

Specific composition of alnico alloy powder used in the invention.

For example, Ni15~28%, At6~
.

15%, COO~35% (?1L□~6@,
Tio~9%, Zr.

Examples of the composition include O~3%, SiQ~3%, Mn less than 1%, and the balance actually consisting of Fa.

The present invention will be explained below based on Examples, but the scope of the present invention is not limited by the Examples.

5 Example 1 Alnico 8 series return scrap (runner) was sequentially crushed using a stamp mill, a jig crusher, and a ball mill, and then sequentially crushed to -200 and +200 using a vibrating sieve.
Powders of ~-1oo and +1[]0 were obtained. Then, in a similar manner, %I's, CoA! :I'i, I'
eV'i.

Each powder of Fe-5Mt, Ni, Co, and Crb was in the above particle size range.

Prepared each. Mix each of these powders appropriately.

1 weight ratio: A18%, Ni 15%, Co3
5%, Cu 2.5゜%, Ti 5% balance actual value F
Alnico magnet consisting of e.

Alloy powder was created. Table 1 shows the sample numbers and powder mixing ratios. Note that in this embodiment,

Turn scrap powder and other metals and combinations.

The mixing ratio with gold powder was set to 812 in terms of weight ratio.

Table 1 11+ In order to make the powders shown in Table 1 as similar as possible to the same conditions, 05% by weight of KAO wax was added as a binder, and then the powders were mixed using vertical twin rolls (Freund rolls).

(Industrial Exhibition) granulation was performed. Next, 8゜ton
Molding was carried out at a pressure of
#II+).

A molded body was obtained. Place the obtained molded body in a vacuum.

Then heat to 400℃ at 1.5v/JL to remove the binder.

and then in vacuum (10 Torr) at 1300
℃.

Sintering was performed under the conditions of X3J. Then 1250℃ x IJ solution.

1 in a magnetic field of 30,000 e.
The sample was held at l+830 t: and subjected to multi-stage aging after isothermal magnetic field treatment.

The obtained magnetic properties are shown in Table 2.

As is clear from the table, the samples containing 50% or more of -200 Messy raw material powder had high sintered density and excellent magnetic properties. On the other hand, when the -200 mesh powder becomes less than 60 inches, the sintered density also decreases, but the decrease in Bτ among the magnetic properties is more significant. The reason for this is that the particle size of the raw material powder becomes large.

Uniform diffusion of constituent atoms is inhibited during sintering.

This is thought to be due to local non-uniformity of the components.

It will be done.

Examples 2 and 1゜ After blending the required raw materials so that the composition distribution was the same as in Example 1, the ingot obtained by melting in the atmosphere, casting and cooling was processed in the same manner as in Example 1. By.

Crush, -200 mesh, +200 to -100 mesh.

The powders of 1 and +100 m were classified. This one After adjusting the powder to the blending ratio shown in Table 3, it was added to the powder.

The weight of camphor is 1 in alcoholic solution of unou compared to powder.
% was added and granulation was performed.

7.

Table 5 Next, molding, sintering 1+, and heat treatment were performed in the same manner as in Example 1 to obtain the magnetic properties shown in Table 4. .

Table 4 As is clear from the table, the particle size of the raw material powder differs from the magnetic one.

The chemical properties show the same tendency as in Example 1. Furthermore, Fa.

Ni, Co-AL-Ti, Fa-50Al
, Example 1 using FeTi metal and alloy powder as 100% starting materials.

Even when sintered magnets were manufactured under similar conditions, the behavior of magnetic properties with respect to the particle size of the raw material powder is as shown in Table 2.

and shows almost the same trends as in Table 4.

As described above, according to the present invention, At-Ni-Ce-Fe system or Δt-N
i-.

When Fa-based magnetic alloy is manufactured by powder metallurgy, Ill
I can do that.

Claims (1)

[Claims] At-
・Ni-Co-Fg system or At-Ni-F
A powder consisting of a g-based alloy component and a main component of 200 mesh or less. After mixing with a powder consisting of an element constituting an auxiliary component or an alloy consisting of six of these elements and press-forming, the mixture is placed in a vacuum or a non-oxidizing atmosphere. A method for molding a permanent magnet alloy, the method comprising: obtaining a 41-Ni-Co-F-based or Al-Ni-:yFt-based sintered magnet alloy.