JPH06204016A - Manufacture of rare earth intermetallic compound magnetic material composed of rare earth compound - Google Patents

Abstract

PURPOSE:To manufacture rare earth intermetallic compound magnetic material which contains nitrogen, carbon, boron, etc., at low cost by using corresponding rare earth nitride, carbide, boride, etc., as the material. CONSTITUTION:Rare earth nitride, carbide, boride, etc., composed of rare earth compounds such as rare earth oxide and halide lower in cost than metal are high frequency fused or arc fused with iron, cobalt, titanium, etc., and intermetallic compound which contains corresponding non-metal ingredients such as nitrogen, carbon, boron, etc., is manufactured. The concentration of nitrogen, carbon, boron, etc., contained in a sample is adjusted at need by heat treatment in various types of atmospheres such as hydrogen and adding a small quantity of rare earth metal, iron, cobalt, carbon, boron, etc., and fusing it again.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the production of rare earth intermetallic compound magnetic materials starting from inexpensive rare earth nitrides, carbides, borides, etc., in place of conventional rare earth metals.

[0002]

2. Description of the Related Art Conventional rare earth intermetallic compounds are prepared by using expensive rare earth metals as raw materials, iron, cobalt, titanium,
It is manufactured by adding carbon, boron, etc. and melting, and subsequently heating the obtained mother alloy in a nitrogen or ammonia atmosphere.

[0003]

In the conventional method for producing a rare earth intermetallic compound, an expensive rare earth metal is used as a starting material, so that the production cost is high and the demand as a magnetic material is largely hindered. Therefore, it is necessary to produce a rare earth intermetallic compound without using an expensive rare earth metal as a raw material, and to significantly reduce the production cost.

[0004]

In order to achieve the above object, it is indispensable to develop a manufacturing process in which the manufacturing cost of the rare earth component in the rare earth intermetallic compound is significantly reduced. It is characterized in that a rare earth intermetallic compound is produced using a cheaper rare earth nitride, carbide, boride or the like as a starting material.

[0005]

In the present invention, the rare earth intermetallic compound can be produced by using, as a starting material, a rare earth nitride, a carbide or a boride obtained by a known method from an inexpensive rare earth oxide or halide.

The production can be carried out by adding an appropriate amount of iron, cobalt, titanium or the like to rare earth nitrides, carbides, borides and the like, and high frequency or arc melting.

Further, the obtained compound is heat-treated in an appropriate atmosphere including hydrogen, and an appropriate amount of rare earth metal, iron, cobalt, carbon, boron or the like is further added to the compound and melted again. Therefore, Ln ₂ Fe ₁₇ N _x , Ln ₂ Fe ₁₇
It is possible to produce rare earth intermetallic compounds such as C _y N _x , NdFe ₁₁ TiN _x , and Nd ₂ Fe ₁₄ B.

[0008]

EXAMPLE A rare earth nitride,
Ln ₂ Fe ₁₇ N _x , Ln ₂ with carbides and borides as starting materials
Fe ₁₇ C _y N _x , NdFe ₁₁ TiN _x , Nd ₂ Fe ₁₄ B and other rare earth intermetallic compounds can be produced.

The production was carried out by adding iron, cobalt, titanium or the like to the above rare earth compound and subjecting it to high frequency or arc melting. If necessary, the obtained compound is heat-treated in a suitable atmosphere including hydrogen.
Further, an appropriate amount of rare earth metal, iron, cobalt, carbon, boron or the like was added to this and high frequency melting was performed to obtain the above intermetallic compound.

FIG. 2 shows the X-ray diffraction pattern of a sample obtained by high-frequency melting of a SmN-Fe mixture having a molar ratio of 2:17, together with that of the mixture before melting. Before melting, diffraction peaks attributed to SmN and α-Fe are observed, whereas
After melting, the SmN peak disappeared and the α-Fe peak became broad. This indicates that SmN reacted with Fe as it melted, producing an amorphous Sm-Fe-N phase and an α-Fe phase with reduced crystallinity. The composition of this sample was about Sm: Fe: N = 2: 17: 2 in molar ratio.

On the other hand, FIG. 2 (c) shows an X-ray diffraction pattern of a sample obtained by adding Sm and Fe to the above sample so as to have a composition of Sm ₂ Fe ₁₇ N and melting the sample. A diffraction pattern having a main peak of Sm ₂ Fe ₁₇ N _x was observed at 2θ = 41 to 42 °, which shows that the target rare earth intermetallic compound was formed. Further, since the intensity of the diffraction peak is weak and broad, the crystallinity of the sample is considered to be low, but this is closely related to the nitrogen content, and the crystallinity is improved by reducing the nitrogen content.

FIG. 3 shows an X-ray diffraction pattern of SmC ₂ synthesized by a known method from samarium oxide and graphite powder and a similar X-ray diffraction pattern of a sample obtained by arc melting SmC ₂ and Fe with a molar ratio of 2:17. Indicates. Sm-Fe-N by arc melting
Similar to the system, the SmC ₂ diffraction peak disappeared, and only the broad α-Fe peak was observed. Again, SmC ₂ is Fe
Reacts with the amorphous Sm-Fe-C phase and α-Fe with reduced crystallinity
It indicates that a phase has formed. Although the composition of this sample was slightly reduced in Sm component, the molar ratio was Sm: Fe: C = 2: 1.
It was close to 7: 4.

Similarly, the composition of Sm ₂ Fe ₁₇ C _0.5
3 (c) shows the X-ray diffraction pattern of the sample obtained by adding Sm and Fe so that Sm ₂ Fe ₁₇ at 2θ = 42 to 43 °
The diffraction pattern with the main peak of C _x is observed, which shows that the target rare earth intermetallic compound is produced. Also in this case, the crystallinity of the sample decreased as the carbon content increased.

[0014]

INDUSTRIAL APPLICABILITY Since the present invention uses an inexpensive rare earth compound as a starting material, it is effective in significantly reducing the production cost thereof as compared with a rare earth intermetallic compound produced from a usual rare earth metal.

[Brief description of drawings]

FIG. 1 is a manufacturing process drawing of a rare earth intermetallic compound.

FIG. 2 is a powder X-ray diffraction pattern. However, (a) is SmN / Fe
(Mole ratio = 2:17) mixture, (b) the same sample after high frequency melting, and (c) Sm ₂ Fe ₁₇ N in the sample (b) so that Sm ₂ Fe ₁₇ N.
Is a sample obtained by high-frequency melting.

FIG. 3 is a powder X-ray diffraction pattern. However, (a) is SmC ₂ ,
(b) is a sample in which SmC ₂ was arc-melted by adding Fe so that the molar ratio was 2:17, and (c) was added Sm and Fe to sample (b) so that it was Sm ₂ Fe ₁₇ C _0.5. It is a sample melted by arc.

Claims (1)

[Claims] 1. Ln ₂ Fe ₁₇ N _x , Ln ₂ Fe ₁₇ C _y N _x , NdFe ₁₁ TiN _x ,
Rare earth intermetallic compounds represented by Nd ₂ Fe ₁₄ B (Ln: rare earth element), etc. are used as starting materials for rare earth compounds that are cheaper than rare earth metals, such as rare earth nitrides, carbides and borides. A technology for producing high-performance magnetic materials by mixing and melting cobalt, cobalt, titanium, etc.