JPS63249302A - Manufacture of r-fe-b system magnet alloy powder - Google Patents

Abstract

PURPOSE:To improve the efficiency of grinding in fine grinding by pulverizing further roughly ground powder which contains 200-5000 ppm hydrogen by roughly grinding a specific component cast block in an atmosphere of the hydrogen. CONSTITUTION:A cast block which has the main components of 10 atom %-30 atom % R (R is at least one sort among the rare earth elements which contain Y.), 65 atom %-82 atom % Fe and 2 atom %-28 atom % B is roughly ground in an atmosphere of hydrogen and roughly ground powder which contains 200-5000 ppm hydrogen is further pulverized. By pulverizing after the contained quantity of the hydrogen in the roughly ground powder is made 200-5000 ppm, the pulverizing is made easy and the yield and the efficiency of grinding of pulverized powder are improved.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention provides an R-Fe alloy containing R (wherein R is at least 1 m of rare earth elements including Y), Fe, and B as main components.
The present invention relates to a method for producing -B-based magnet alloy powder.

[Conventional technology]

In recent years, R-Fe-B magnets, which do not contain Sm or CO, which have higher magnetic properties and are more expensive in terms of resources than conventional Sm-Co magnets (R is a rare earth element containing Y), have been developed. At least one of the elements) is attracting attention (Sayo et al., J.
, ApPI, Ph)'s, 55(6), 15 Ma
rch.

1984, p2083-2087 and JP-A-59-4
No. 3008, No. 59-215430, No. 59-217
i4 issue.

(See Publication No. 59-222564, etc.).

For example, the following method is known as a method for manufacturing the above-mentioned R-Fe-B magnet.

After high-frequency melting of starting materials consisting of 11fl# iron, ferroboron, rare earth metals, etc., the ingots obtained by casting into a mold are coarsely ground using a stamp mill or the like, and then made into fine powder of 3 to 10 μm using a ball mill or the like. Then, this fine powder is distributed in a magnetic field, shaped, and then fused.

The above-mentioned an <, the present magnetic alloy powder can be obtained by mechanically crushing and finely pulverizing an ingot of the required composition, but the present kawaseki alloy is extremely difficult to crush, and the coarsely pulverized powder becomes flat. However, there are drawbacks such as the high load of the crusher and the high wear rate.

[Problems to be Solved by the Invention]] In order to solve the above-mentioned drawbacks, a method for producing magnetic alloy powder that is caused to spontaneously disintegrate in a hydrogen atmosphere has recently been proposed (
JP-A-30-63504, JP-A No. 30-119701,
61-139303, etc.) 0, that is, R (at least one rare earth element including RFiY) 10 to 30 atoms, Fe65 to 82 atoms, B2 to 28 atoms After breaking the ingot mainly composed of , the broken ingot was placed in a sealed container, and the air in the container was replaced with H2 gas.
200 Torr to 50 kf/d of H2 in the vessel
A magnet alloy powder is produced by supplying a gas and dehydrogenating the obtained spontaneously disintegrating alloy powder by heating it to 100 to 500°C in a vacuum and argon gas to completely remove hydrogen, and then finely pulverizing it. This is the manufacturing method.

However, since hydrogen is completely removed from the naturally disintegrating alloy powder by dehydrogenation treatment, it is difficult to pulverize it, resulting in problems such as poor yield of pulverized powder and poor pulverization efficiency.

[Means for solving problems]

In order to solve the above-mentioned problems, the inventors of the present application have conducted extensive research, and as a result, the amount of hydrogen contained in the coarsely pulverized powder has been reduced to 200 to 500.
It has been found that the grinding efficiency can be improved by finely grinding after reducing the amount to
An ingot whose main components are 10 atomic % to 30 atomic Ti*, Fe 65 atomic % to 82 atomic %, and B2 atomic Ti to 28 atomic Ti is coarsely ground in a hydrogen atmosphere, and the amount of hydrogen contained is 200 to 5000.
The percentage indicates that the coarsely pulverized powder of ppm is further finely pulverized.

The rare earth element R contained in the R-Fe-B magnet alloy ingot of the present invention is a rare earth element that includes yttrium (Y) and includes light rare earths and heavy rare earths. %KNd.

Pr is preferred. In addition, although one type of metal is usually sufficient, in practice, a mixture of two or more types (mitshumetal, didymium, etc.) can be used for reasons such as convenience of availability.
Sm*YaLa+CeGd, etc. can be used as a mixture with other R9, especially Nd, Pr, etc. Note that R in and does not have to be a pure rare earth element, and may contain impurities that are unavoidable in production within an industrially available range.

R (at least one rare earth element including Y) is essential for the alloy ingot for manufacturing the above-mentioned novel magnet, and is 10
If the amount is less than 1, high magnetic properties, especially high coercive force, cannot be obtained, and there is no occlusion property, so it cannot be pulverized by pulverization.
If it exceeds 30 atoms, the residual magnetic flux density decreases and an excellent permanent magnet cannot be obtained.

Fe is an essential element in the alloy ingot used to manufacture the above-mentioned new magnets; if it is less than 65 atoms, the residual magnetic flux density decreases, and if it is more than 82 atoms, high coercive force cannot be obtained.

B is an essential element of the alloy ingot used to manufacture the above-mentioned new magnet, and if it is less than 2 atoms, a high coercive force cannot be obtained.
In addition, since it does not have H storage properties, it cannot be pulverized into a fine powder by pulverization.
If the number exceeds 8 atoms, the residual magnetic flux density decreases, making it impossible to obtain an excellent permanent magnet.

In the alloy ingot of the present invention, in order to obtain an excellent permanent magnet having both a high residual magnetic flux density and a high coercive force, it is particularly necessary to contain R12 atomic % to 2O atomic % + Fe30 atomic % to 84 atomic %.
At %, B44 atoms to 24 atoms are preferable.

In addition, the alloy ingot according to the present invention can contain impurities other than R, Fe + 'B, which are inevitable in industrial production, but a part of B can be replaced by C, 3, 3, By substituting at least one of 5% atomic atoms below P, 8 below 2.5 atoms, and Cu below 3.5 atoms in a total amount of below 4.0 atoms, the water-based magnetic alloy can be improved. It is possible to improve manufacturability and lower prices.

Further, in the R+ Fe t B alloy, At of 9.5 atoms or less, Ti of 4.5 atoms or less, V of 9.5 atoms or less, Cr of 8.5 atoms or less, Mn of 8.0 atoms or less
e 5 atoms or less Bi 12.5 atoms or less N
b, Ta of 10.5 atoms or less; Mo of 9.5 atoms or less;
* 9-5 atoms or less W2.5 atoms or less 18b
, Ge with less than 7 atoms, Sn with less than 35 atoms, Zr with less than 5.5 atoms, and Hf with less than 5.5 atoms. By adding and containing at least one of the following, it is possible to increase the coercive force of the water-based magnetic alloy. Become.

The naturally disintegrating hydrogen of the present invention is necessary to improve the efficiency of pulverization, and if the hydrogen content is less than 200 ppm, the pulverization properties are poor, and if it exceeds 5000 ppm, the naturally disintegrating material becomes active. Because of this, it is easily oxidized during pulverization, leading to a decline in magnetic properties.

〔Example〕

Next, examples of the present invention will be described, but the present invention is not limited to these examples.

Example 1 As a raw material, electrolytic iron with a purity of 99.9 wt%, B 20
．． Using a ferroboron alloy containing 0 wt% and the remainder consisting of impurities such as Fe and C, and R containing Nd and Dy with a purity of 95 wt% or more, the atomic composition was 13% N.
The final welded body of d-2% Dy-7 and B-remaining Fe was weighed and melted in an inert gas (Ar) to obtain an alloy ingot.

After this alloy ingot was fractured, the fracture tool 1 9 was placed in a closed container, and H2 gas was introduced to perform H2 treatment.

The obtained coarse powder, which naturally disintegrated due to H2 absorption, was coarsely pulverized to have a hydrogen content of 1700 ppmKL and 32 mesh through 1. Next, 5009 of this coarsely pulverized powder was molded into a molding fine powder with an average particle size of 2.5 to 4 μm using a jet mill at a molding pressure of 3 tons in a magnetic field (18 KOe) to obtain a molded product. . The obtained compact was sintered in Ar gas (1100°C x I Hr ) to produce a permanent magnet.

Table 1 shows the time for pulverization using a jet mill, the average particle size of the fine powder, and the amount of hydrogen contained.

Comparative Example 1゜The hydrogen content of the coarse powder in Example 1 was changed to 1100 pp,
32 Of the coarsely ground powder crushed in mesh through 1, 3
00? was finely pulverized using a jet mill. As the results are shown in Table 1, it can be seen that the crushing efficiency in crushing was poor.

Example 2゜ As raw materials, electrolytic iron with a purity of 99.9 wt%, B20.0
Using a 7-engineered roboron alloy containing 15%Nd-7%B-remaining Fe with an atomic composition of 15%Nd-7%B-remaining Fe, using a 7-functional roboron alloy containing 7% wt% and the remainder consisting of impurities such as Fe and C, and Nd with a purity of 95wt% or more as R. Weigh and inert gas (Ar) to obtain a sintered body.
) to obtain an alloy ingot.

After breaking this alloy ingot, use a breaking tool of 1kt.
- It was placed in a closed container, and gas was introduced into it to perform gas treatment.

The resulting coarse powder, which was naturally disintegrated by hydrogen absorption, had a hydrogen content of 2,500 ppm, and was coarsely pulverized with 32 meshes through 1. Next, 300 f of this coarsely pulverized powder was processed using a jet mill to form fine powder for molding with an average particle size of 2.5 to 4 μm in a magnetic field (18 KOe) at a molding pressure of 5 ton/6 I.
) to obtain a molded product. The obtained compact was sintered in Ar gas (1100°C X I Hr ) to produce a permanent magnet.

Table 2 shows the time for pulverization using a jet mill, the average particle size of the fine powder, and the amount of hydrogen contained.

Comparative Example 2゜ The hydrogen content of the coarse powder in Example 2 was set to 1501)I)m, and the coarsely ground powder ground with 52 mesh through 1 was finely pulverized using a 5oot jet mill. . As the results are shown in the second light, it can be seen that the pulverization efficiency in fine pulverization is poor.

Table 1 Table 2 [Effects of the Invention] According to the present invention, improvement in pulverization efficiency in fine pulverization can be achieved as compared to conventional methods.

Claims (1)

[Claims] R (where R is at least one rare earth element including Y) 10 atomic% to 30 atomic%, Fe65 atomic% to 8
An ingot whose main components are 2 atomic% and B2 atomic% to 28 atomic% is coarsely pulverized in a hydrogen atmosphere, and the hydrogen content is 200 to 50%.
A method for producing R-Fe-B magnet alloy powder, which comprises further pulverizing coarsely pulverized powder of 00 ppm.