JPH0663073B2 - Method for producing manganese-aluminum-carbon alloy magnet - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a permanent magnet, and more particularly, to a high-performance multi-pole magnetized with a polycrystalline manganese-aluminum-carbon (Mn-Al-C) alloy magnet. For manufacturing Mn-Al-C alloy magnet for use in automobiles.

ART Mn-Al-C alloy magnet is composed of mainly face-centered tetragonal (tau phase, L1 ₀ type ordered lattice) is a ferromagnetic phase of tissue, C
Is included as an essential constituent element, and a ternary alloy magnet containing no additional element other than impurities and a quaternary or more multi-component alloy magnet containing a small amount of additional element are known, and these are collectively referred to. .

Conventionally, the manufacturing method is such that the outer periphery of a hollow body billet made of an alloy for Mn-Al-C magnets is constrained by an outer mold,
A punch having a flat compression surface was used for compression processing (Japanese Patent Laid-Open No. 192306/58).

Problems to be Solved by the Invention According to the above-described conventional manufacturing method, the billet is subjected to substantially the same compressive strain both in the billet and the outer peripheral portion thereof. It becomes a substantially straight line in the radial direction like the line A.

Therefore, in this state, even if S and N are magnetized on the outer circumference or the inner circumference as shown in the figure, the ideal semi-circular B line which is the ideal easy magnetization direction array is too much. Since the arrangement of the easy magnetization direction is different, a strong magnetic force could not be obtained even when the magnetizing work was performed.

Therefore, in the above-mentioned conventional example, as shown in FIG.
Before magnetizing N, the inner peripheral portion of the compressed billet is compressed again to bring the easy magnetization direction array to a substantially semi-circular shape as shown in FIG. 6 of the present application, and thereafter magnetizing the inner periphery. I was trying to do the work.

However, in the conventional case, in order to obtain such a substantially semi-circular easy direction alignment, the inner circumference or the outer circumference of the billet must be compressed again after the compression of the billet, resulting in poor workability. It was

Therefore, the present invention, in which S, N is magnetized to the inner peripheral portion of the billet, to make it possible to easily obtain a substantially semi-circular easy magnetization direction array, and another billet outside the billet. It is intended to be integrated.

Means for Solving the Problems And, in order to achieve this object, the present invention provides a preformed anisotropy of polycrystalline manganese-aluminum-carbon in the hollow portion of a hollow first billet made of a metal material. In the presence of the hollow body-shaped second billet made of a system alloy magnet, at a temperature of 530 to 830 ° C., a punch is used to compress the first and second billets in the axial direction. The compression surface is first from the outer peripheral portion toward the inner peripheral portion,
The second billet in the form of a hollow body, which has an inclination approaching the end of the second billet and is made of the polycrystalline manganese-aluminum-carbon alloy magnet previously anisotropy by the compressed surface of the inclined punch. Of the hollow body-shaped member until the inner peripheral surface of the first billet and the outer peripheral surface of the second billet come into contact with each other or more, with the compressive strain of the inner peripheral portion of the first billet being larger than that of the outer peripheral portion. The first and second billets are compressed in the axial direction.

With the above configuration, the first hollow-body-shaped first member made of a metal material is used.
In the state where a hollow body-shaped second billet made of a pre-anisotropic polycrystalline manganese-aluminum-carbon magnet alloy is provided in the hollow part of the billet,
When the second billet is axially compressed by the punch, the compression surface of the punch moves from the outer peripheral portion toward the inner peripheral portion in the first and second directions.
Since the second billet has an inclination that approaches the end of the billet, the compressive strain of the inner periphery of the second billet is larger than that of the outer periphery, and as a result, the inner periphery of the second billet after compression is increased. Is easily formed into a semi-circular easy-direction array by one-time compression, and a strong magnetic force can be obtained by magnetizing S and N on the inner circumference of the second billet. Of.

Further, by this compression, the first billet and the second billet for performing post-processing (cutting, etc.) for attachment to other equipment are integrated, so that the manufacturing process from this point as well. It will be simplified.

Example FIG. 1 shows a cross section before processing. 2 is a second billet (a hollow body-shaped billet made of a pre-anisotropic polycrystalline Mn-Al-C alloy magnet) 1 is a first billet (a hollow body-shaped billet made of a metal material) , 4 and 5 are punches, and 6 is an outer type. As shown in FIG. 1, the compression surface 4a, which contacts the billets 1 and 2 of the punch 4 and the punch 5,
5a is the first and second billets 1, from the outer circumference to the inner circumference.
It has a slope approaching the end of 2. By using the punch 4 and the punch 5 to press the billets 1 and 2 in the axial direction, the billets 1 and 2 are compressed in the axial direction. In FIG. 1, the heights of the first billet 1 and the second billet 2 before processing are the same. The height of the inner peripheral portion is lower than the height of the outer peripheral portion of each billet 1 and 2 after processing. In other words, the billets 1 and 2 were compressed in the axial direction so that the compressive strain on the inner peripheral portions of the billets 1 and 2 was larger than the compressive strain on the outer peripheral portions. Compressive strain refers to the axial strain of billets 1 and 2.

That is, in the present embodiment, the hollow portion of the first billet 1 having a hollow body shape made of a metal material has a hollow body shape made of a pre-anisotropic polycrystalline manganese-aluminum-carbon magnet alloy. The first and second billets 1 and 2 are axially compressed by the punches 4 and 5 in the state where the billet 2 is provided. Since the second billet 2 has an inclination that approaches the ends of the first and second billets 1 and 2 toward the periphery, the compression strain of the second billet 2 becomes greater than the compression strain of the outer periphery. As a result, in the inner peripheral portion of the second billet 2 after compression, a substantially semicircular easy magnetization direction array is easily formed by one compression as shown by line B in FIG. Magnetization of S and N on the inner circumference of the billet 2 will result in strong magnetic force. That.

Further, because of this compression, the first billet 1 and the second billet 2 for performing post-processing (cutting processing, etc.) for attachment to other equipment are integrated, and from this point as well, the manufacturing process Will be simplified.

2 to 5 show another embodiment. In the embodiment shown in FIG. 2, a punch provided with a gap between the first billet 1 and the second billet 2 is compressed by punches 4 and 5. Is.

FIG. 3 shows that the outer peripheral surface of the second billet 2 is the first billet 1.
Is in contact with the inner peripheral surface of the first billet 1 and the outer mold 6
What is provided with a gap between and is to be axially compressed by the punches 4, 5.

FIG. 4 shows that a cylindrical billet 3 is provided in the second billet 2 and is axially compressed by the punches 4 and 5.

FIG. 5 shows the second and third billets 2 in the first billet 1,
3 is provided and the opposing surfaces of these three billets 1 to 3 are brought into contact with each other to be axially compressed by the punches 4 and 5.

Next, more specific examples of the present invention will be described.

(Figure 2) 69.5% Mn, 29.3% Al, 0.5% C and 0.7
% Ni was melted and cast to produce a cylindrical billet having a diameter of 60 mm and a length of 40 mm. The billet was held at 1100 ° C. for 2 hours and then heat-treated to cool to room temperature.

Next, extrusion processing was performed at a temperature of 720 ° C. through a lubricant. The billet after processing had a diameter of 40 mm and a length of 90 mm. This extruded rod is cut and cut to have an outer diameter of 35 mm and an inner diameter.
29 mm, 20 mm long cylindrical second billet 2 and brass rod from 40 mm outer diameter, 35 mm inner diameter, 20 mm long first cylinder
Billet 1 of each was produced. The second billet 2 is put in the hollow part of the first billet 1 and is put through a lubricant to
At a temperature of 0 ° C., compression processing was performed by punches 4 and 5 from the state shown in FIG. The outer mold 6 has an inner diameter of 40 mm and an inclination angle (α)
Is 10 °, and the height of the outer periphery of billets 1 and 2 after processing is 1
It was 5 mm.

After machining the billets 1 and 2 after processing to an inner diameter of 25 mm, the inner circumference was magnetized with 24 poles and the surface magnetic flux density was measured.

For comparison, the same billets 1 and 2 as described above were used to perform compression processing using a die having punches 4 and 5 having a flat compression surface and an outer diameter of 6, and the billet was also formed in the same manner as described above. After cutting, a magnet with 24 poles was magnetized on the inner circumference.

Comparing the above two values, the value of the surface magnetic flux density of the magnet obtained by the method of this example was about 1.2 times that of the magnet produced for comparison.

In the above examples, the composition of the Mn-Al-C alloy magnet is shown only for the quaternary system containing Ni and the quinary system containing Ni and Ti. Even in the ternary system, which is the basic composition, a slight difference was observed in the magnetic characteristics of the magnet, but the improvement in the magnetic characteristics as described above was recognized by the known compression processing method.

In addition, an example in which a uniaxial anisotropic magnet or a plane anisotropic magnet is used as the Mn-Al-C based alloy magnet that has been anisotropy in advance is shown, but the same applies when a diameter anisotropic magnet or the like is used.

EFFECTS OF THE INVENTION As described above, according to the present invention, the hollow portion of the first billet in the form of a hollow body made of a metal material is made of a pre-anisotropic polycrystalline manganese-aluminum-carbon-based magnet alloy. The first and second billets are axially compressed by a punch in a state where the second billet of the punch is provided, and the compression surface of the punch is the first and the second from the outer peripheral portion toward the inner peripheral portion. Since the second billet has an inclination that approaches the end of the billet, the compressive strain of the inner periphery of the second billet is larger than that of the outer periphery, and as a result, the inner periphery of the second billet after compression is increased. Is easily formed into a semi-circular easy-direction array by one-time compression, and a strong magnetic force can be obtained by magnetizing S and N on the inner circumference of the second billet. Of.

In addition, this compression integrates the first billet and the second billet for post-processing (cutting, etc.) for attachment to other equipment, for example, so that the manufacturing process is simplified from this point as well. Will be realized.

[Brief description of drawings]

1 to 5 are cross-sectional views of an embodiment of the present invention, and FIG. 6 is a diagram showing an easy magnetization direction arrangement. 1 ... 1st billet, 2 ... 2nd billet, 3 ...
3rd billet, 4,5 ... punch, 4a, 5a ... compression surface, 6
…… Outer mold, α …… Inclination angle.

Claims (5)

[Claims] 1. A hollow body-shaped second billet made of a pre-anisotropic polycrystalline manganese-aluminum-carbon alloy magnet is present in the hollow portion of a hollow body-shaped first billet made of a metal material. In this state, the punch is configured to compress the first and second billets in the axial direction at a temperature of 530 to 830 ° C., and the compression surface of the punch is the first from the outer peripheral portion toward the inner peripheral portion. A second hollow billet having a slant that approaches the end of the second billet and is made of the polycrystalline manganese-aluminum-carbon alloy magnet previously anisotropy by the compression surface of the slanted punch. Of the hollow body-shaped member until the inner peripheral surface of the first billet and the outer peripheral surface of the second billet come into contact with each other or more, with the compressive strain of the inner peripheral portion of the first billet being larger than that of the outer peripheral portion. First and second Manganese to the compression process in the axial direction of Rett - Aluminum - preparation of carbon-based alloy magnets. 2. The method for producing a manganese-aluminum-carbon based alloy magnet according to claim 1, wherein at least the inner peripheral portion of the first hollow billet made of a metal material is made of a magnetic material. 3. Pre-anisotropic polycrystalline manganese-
Second hollow body made of aluminum-carbon alloy magnet
Is composed of a polycrystalline manganese-aluminum-carbon alloy magnet having an easy magnetization direction array in the axial direction of the hollow body, and the compressive strain is an absolute value of logarithmic strain.
The method for producing a manganese-aluminum-carbon alloy magnet according to claim 1 or 2, which has a value of 0.03 or more. 4. Pre-anisotropic polycrystalline manganese-
Second hollow body made of aluminum-carbon alloy magnet
The billet has an easy magnetization direction array parallel to a plane perpendicular to the axial direction of the hollow body, and is magnetically isotropic in the plane, and a straight line parallel to the axial direction and the plane is formed. The method for producing a manganese-aluminum-carbon alloy magnet according to claim 1 or 2, comprising a polycrystalline manganese-aluminum-carbon alloy magnet which is anisotropic in the plane containing the magnet. 5. Pre-anisotropic polycrystalline manganese-
Second hollow body made of aluminum-carbon alloy magnet
The method for producing a manganese-aluminum-carbon alloy magnet according to claim 1 or 2, wherein the billet comprises a polycrystalline manganese-aluminum-carbon alloy magnet having an easy magnetization direction array in the radial direction.