JPH0639672B2 - Method for producing manganese-aluminum-carbon alloy magnet - Google Patents

Description

The present invention relates to a method for manufacturing a permanent magnet. More specifically, the present invention relates to a method for producing a polycrystalline manganese-aluminum-carbon system (Mn-Al-C system) alloy magnet, and particularly to a method for producing a Mn-Al-C system alloy magnet for multipolar magnetization. is there.

2. Description of the Related Art Mn-Al-C magnet alloy is a general term for Mn-Al-C magnet alloy and Mn-Al-C alloy magnet.
The Mn-Al-C magnet alloy has a Mn content of 68 to 73% by weight (hereinafter simply referred to as "%") and (1/10 Mn-6.6).
~ (1 / 3Mn-2.22)% C and the balance of Al, ternary system containing no additional element other than impurities and quaternary or more multi-element system alloys for magnets are known. Are collectively referred to. Similarly, 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. .

Further, as a method for producing this Mn-Al-C alloy magnet, a method including a warm plastic working step such as warm extrusion processing is known in addition to the method by casting and heat treatment. In particular, the latter is known as a method for producing an anisotropic magnet having excellent properties such as high magnetic properties, mechanical strength, weather resistance and machinability.

As a method for producing the Mn-Al-C alloy magnet for multipolar magnetization, an isotropic magnet, a compression processing method, or a uniaxially anisotropic polycrystalline Mn obtained by a known method such as warm extrusion processing in advance.
-Al-C alloy magnet by warm free compression in an anisotropic direction, and by various plastic working that gives compressive strain in the axial direction of a hollow billet made of Mn-Al-C magnet alloy And a billet in the form of a hollow body made of a Mn-Al-C based magnet alloy, which is subjected to axial compression processing in the state where a billet made of a metal material is present in the hollow part of the billet (Japanese Patent Laid-Open No. 60-59720). And JP-A-60-
No. 59055, herein referred to as 2-billet simultaneous compression processing (method).

Problems to be Solved by the Invention According to the two-billet simultaneous compression processing method described above (especially,
In Japanese Patent Laid-Open No. 60-59720), that is, a hollow body-shaped billet made of a pre-anisotropic polycrystalline Mn-Al-C alloy magnet is present in the hollow portion of the hollow body-shaped billet made of a metal material. In the method of compressing in the axial direction of the hollow-body-shaped billet made of the pre-anisotropic polycrystalline Mn-Al-C alloy magnet, a uniaxial method obtained by a known method such as extrusion is used. Anisotropic polycrystalline Mn-
A hollow body billet made of an Al-C alloy magnet is used. By subjecting the billet to the two-billet simultaneous compression process described above, a magnet exhibiting excellent magnetic characteristics when multi-polarized is obtained. However, the above-mentioned method requires at least two types of plastic working, that is, the known extrusion process and the above-mentioned two-billet simultaneous compression process, and the known extruded billet has an easy-value direction in the extrusion direction.
A magnetic anisotropy structure is converted into a magnet that exhibits excellent magnetic properties when multi-polarized by billet simultaneous compression processing. In other words, the well-known extruded billet has a uniaxial anisotropy having an easy magnetization direction in the axial direction of the billet, an anisotropic structure not suitable for multipolar magnetization, and the following plastic working (2 billet simultaneous compression). By processing), the magnetic properties in the radial and circumferential directions are improved, and the magnetic anisotropy structure is converted into a magnet exhibiting excellent magnetic properties when magnetized in multiple poles.

When a uniaxial anisotropic magnet (anisotropic magnet not suitable for multi-pole magnetization) is once made by extrusion by the above-mentioned method, and then multi-pole magnetized by the next plastic working (two billet simultaneous compression working) Since the structure is changed to a magnet showing excellent magnetic characteristics, the manufacturing method is wasteful in terms of magnetic characteristics.

The present invention aims to obtain excellent magnetic properties with a small amount of processing.

In order to achieve this object, the present invention provides manganese-
A hollow body-shaped billet made of an aluminum-carbon magnet alloy has a hollow cross-sectional shape of the hollow portion of the container portion at a temperature of 530 to 830 ° C., and the opening area of the container portion is larger than that of the bearing portion. Extruding is carried out in parallel with the axial direction of the billet and the extrusion direction, and the hollow billet is extruded in the axial direction and in the circumferential direction by the extrusion process, and is further made of a metal material. In the hollow part of the other billet, the manganese-
In the presence of the extruded billet in the form of a hollow body made of an aluminum-carbon magnet alloy, until the two billets come into contact with each other, or more, a hollow body made of the manganese-aluminum-carbon magnet alloy. The billet is compressed in the axial direction.

Operation According to the above-described method, that is, after performing the above-mentioned specific extrusion processing, by performing the above-mentioned known 2 billet simultaneous compression processing, after performing the above-mentioned known extrusion processing, the above-mentioned known 2 Even if the total plastic working amount is smaller than that of the method of performing simultaneous billet compression processing, a magnet exhibiting excellent magnetic properties can be obtained when magnetized with multiple poles.

Example The present invention provides a hollow body-shaped billet made of a manganese-aluminum-carbon magnet alloy at a temperature of 530 to 830 ° C., in which the hollow section of the container section has a hollow cross-sectional shape, and the opening area of the container section is Using a die that is larger than the opening area of the bearing portion, extrusion processing is performed by making the extrusion direction in parallel with the axial direction of the billet, and the hollow billet by the extrusion processing is expanded in the axial direction and the circumferential direction, Further, the two billets are in contact with each other in a state where the hollow body-shaped extruded billet made of the manganese-aluminum-carbon magnet alloy is present in the hollow part of another hollow body-shaped billet made of a metal material. Up to or more than that, compression processing is performed in the axial direction of the hollow billet made of the manganese-aluminum-carbon magnet alloy.

By subjecting the above-mentioned extrusion process to Mn-Al which has been previously anisotropy by known extrusion processes.
By the method of obtaining a -C alloy magnet, a magnet exhibiting excellent magnetic characteristics when subjected to multi-pole magnetization is obtained even if the amount of strain at the time of the above-mentioned known two-billet simultaneous compression processing is small.

The above-mentioned two plastic workings do not necessarily have to be continuous plastic workings, and may be given by dividing into a plurality of times.

An example of the extrusion processing of the present invention described above will be described with reference to FIG. 1 in which the billet has a cylindrical shape. FIG. 1a is a sectional view of a part of the die showing a state before extrusion,
Similarly, FIG. 1b shows the state after extrusion. 1 is a billet, 2 is a mandrel, 3 is a die, and 4 and 5 are punches. The mandrel 2 and the dice 3 form a dice. In FIG. 1, 6 is a container part, which is a part for accommodating the billet 1 before extrusion. Reference numeral 7 denotes a bearing portion, which is a portion for accommodating the billet 1 after extrusion processing. 8 is a conical part. The opening area of the container portion 6 is the cross-sectional area of the cavity of the container portion 6 (perpendicular to the extrusion direction), which is substantially the same as the cross-sectional area of the billet 1 in FIG. , The cross-sectional area of the cavity of the bearing portion 7 (perpendicular to the extrusion direction), which is substantially the same as the cross-sectional area of the billet 1 in FIG.

In FIG. 1, since both the container portion 6 and the bearing portion 7 are circular with the extruding shaft as the center, in other words, the opening area of the container portion 6 is a ring shape defined by the outer diameter and the inner diameter of the container portion 6. Area. The cross-sectional shape of the hollow portion of the container portion 6 is the above-mentioned ring shape and is hollow. Similarly, the opening area of the bearing portion 7 is a ring-shaped area formed by the outer diameter and the inner diameter of the bearing portion 7. For example, the outer diameter of the container portion 6 is 40 mm, the inner diameter is 20 mm,
50mm outer diameter of the bearing portion 7, when the inner diameter and 40 mm, opening area of the container section 6 about 942 mm ^2, the opening area of the bearing part 7 is approximately 707mm ^2. The cross-sectional shape of the hollow portion of the container portion 6 is a ring shape having an outer diameter of 40 mm and an inner diameter of 20 mm. In other words, the hollow portion of the container part 6 has a hollow cross-sectional shape, which means that when the billet 1 is housed in the container part 6 as shown in FIG. There is a die constituent member (mandrel 2) in the part, the billet 1 is further outside thereof, and the die constituent member (die 3) is further outside thereof.

An example of the extrusion processing method will be described with reference to FIG. First, as shown in FIG. 2A, the cylindrical billet 1'is housed in the container portion 6. By pressing the billet 1'with the punch 4, the state shown in FIG. 2b is obtained. Next, as shown in FIG. 2c, the billet 1 is newly accommodated in the container portion 6, and the punch 4 is used to pressurize the billet 1 in the same manner as described above, whereby the state shown in FIG. 2d is obtained. . Thereafter, extrusion processing is performed by repeating this.

As another extrusion processing method, in the state shown in FIG. 2c, the billet 1 is moved in the direction from the container portion 6 to the bearing portion 7 while pressing the billet 1 with the punches 4 and 5 (in FIG. 2, The state of the billet 1 may be extruded by moving from the state shown in FIG. 2c to the state shown in FIG. 2d.

In Fig. 2a, the shape of the cylindrical billet 1'has a shape with an appropriate clearance in order to facilitate the insertion of the cylindrical billet 1'in the container 6, but the cross section of the cylindrical billet 1 '(in the axial direction The vertical surface) and the cross-sectional shape of the hollow portion of the container portion (the shape of the hollow portion when the die is cut along a plane perpendicular to the extrusion direction) are both ring-shaped.

For the 2 billet simultaneous compression processing method of the next step,
This is similar to the above-mentioned known technique (Japanese Patent Laid-Open No. 60-59720). Typical example of 2 billet simultaneous compression processing method (5
An example) is shown in FIG. In FIG. 3, 9 and 11 are billets made of a metal material (9 is billet A, 11 is billet C), and 10 is the Mn-A extruded as described above.
It is a billet (billet B) made of an I-C type magnetic alloy. Further, in the present invention, the expression "compressing in the axial direction of the hollow billet until the two billets come into contact with each other or more" is also used in the same meaning as in the known art.

Regarding the temperature range in which plastic working as described above is possible,
Machining could be performed in the temperature range of 530 to 830 ° C, but the magnetic properties were considerably deteriorated at a temperature exceeding 780 ° C. A more desirable temperature range is 560 to 760 ° C.
Met.

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

Example 1 In the composition, 69.5% Mn, 29.3% Al, and 0.
Melt casting of 5% C and 0.7% Ni, outer diameter 50m
A cylindrical billet having m, an inner diameter of 35 mm and a length of 20 mm was produced. After holding this billet at 1100 ° C. for 2 hours,
After air-cooling to 00 ° C., holding at 600 ° C. for 30 minutes, heat treatment of allowing to cool to room temperature was performed.

Next, extrusion processing as shown in FIG. 1 was performed at a temperature of 720 ° C. through a lubricant. In Figure 1, the outer diameter of the container part of the die is 50 mm, the inner diameter is 35 mm, the outer diameter of the bearing part is 36 mm, the inner diameter is 28 mm, and x is 20 mm.
Is. The billet after extrusion has an outer diameter of 36 mm and an inner diameter of 28.
mm and the length was 49.8 mm. The billet after processing is cut and cut to have an outer diameter of 35.3 mm, an inner diameter of 29.1 mm,
The length is 20 mm (billet B). Next, the brass bar material was cut and cut to produce a cylindrical billet (billet A) having an outer diameter of 40 mm, an inner diameter of 35.3 mm and a length of 20 mm. Next, the billet B is put into the hollow portion of the billet A, and the billet B is shown in FIG.
In the state shown in Fig. 3, using a mold as shown in Fig. 3c,
Compression processing (two billet simultaneous compression processing) was performed at a temperature of 680 ° C. via a lubricant. In FIG. 3, 3 is a die, 4 and 5 are punches, 9 is a billet A (brass), and 10 is a billet B (Mn-Al-C based magnet alloy). Third
In the figure, the inner diameter of the die 3 is 40 mm. The length of the cylindrical billet after processing was 10 mm.

A cubic sample having a side of 4 mm was cut out from the inner peripheral portion of the billet after processing (the part corresponding to the billet B before processing) so that each side was along the radial direction, the chord direction and the axial direction, and the magnetic properties were measured.

The magnetic characteristics are Br = 6.1 kG and Hc = in the radial direction.
2.9 kOe, (BH) max = 6.6 MG · Oe, Br = 3.0 kG, Hc = 2.2 kOe, (B
H) max = 1.8 MG · Oe, Br = 2.
8 kG, Hc = 2.1 kOe. (BH) max = 1.6
It was MG Oe. The magnet had excellent magnetic properties in the radial direction.

For comparison, M of the same composition as the composition described above
n, Al, C and Ni were melted and cast to form a cylindrical billet having a diameter of 70 mm and a length of 40 mm. This billet is 11
After holding at 00 ° C. for 2 hours, a heat treatment of cooling to room temperature was performed. Then, a known extrusion process up to a diameter of 40 mm was performed at a temperature of 720 ° C. through a lubricant. This extruded rod was cut into a length of 20 mm and cut to produce a cylindrical billet (billet B) having an outer diameter of 35.3 mm, an inner diameter of 29.1 mm and a length of 20 mm. Using the same billet A as above, the same compression processing as above was applied, and a sample was cut out in the same manner as above and the magnetic characteristics were measured.

The magnetic characteristics are Br = 5.9 kG and Hc = in the radial direction.
2.7 kOe. (BH) max = 6.4 MG · Oe, Br = 3.0 kG, Hc = 2.2 kOe, (B
H) max = 1.8 MG · Oe, Br = 2.
8 kG, Hc = 2.1 kOe. (BH) max = 1.6
It was MG Oe.

Comparing the above two values, it can be seen that the value of the magnetic properties in the radial direction of the magnet obtained by the method of the present invention is larger than that of the magnet manufactured for comparison.

Example 2 Using the same billet B as in Example 1, a cylindrical billet (billet A) having an outer diameter of 40 mm, an inner diameter of 35.3 mm, and a length of 20 mm was manufactured using a bar material of pure iron. These billets A
Using billet B, billet B is placed in the hollow portion of billet A, and in the state shown in FIG. 3c, using a mold as shown in FIG. The compression processing was performed at the temperature of. In FIG. 3, the inner diameter of the die 3 is 40 mm. Billet height after compression is 10mm
Met.

The billet that has undergone this compression processing has an outer diameter of 39 mm and an inner diameter of 22.
After cutting to mm, the inner circumference was magnetized with 12 poles. Use a 2000 μF oil condenser for magnetization.
Pulsed with V. The surface magnetic flux density on the inner peripheral surface was measured with a Hall element.

For comparison, the known extruded rod manufactured in Example 1 was cut into a length of 20 mm and cut to have an outer diameter of 35.3 mm and an inner diameter of 2
A cylindrical billet (billet B) having a length of 9.1 mm and a length of 20 mm was produced. Using the same billet A as above, the same compression processing as described above was performed, and the billet was further cut in the same manner as described above, and then 12 poles were 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 the present invention was about 1.2 times that of the magnet produced for comparison.

Example 3 Using the same billet B as in Example 1, a cylindrical billet (billet A) having an outer diameter of 40 mm, an inner diameter of 35.3 mm and a length of 20 mm was produced using a bar of electromagnetic pure iron. Using these billet A and billet B, the billet B was put in the hollow part of the billet A, and in the state shown in FIG. 3c, using a mold as shown in FIG. Then, compression processing was performed at a temperature of 680 ° C. In FIG. 3, the inner diameter of the die 3 is 40 mm. The height of the billet after compression processing is 10
It was mm.

The billet that has undergone this compression processing has an outer diameter of 39 mm and an inner diameter of 22.
After cutting to mm, the inner circumference was magnetized with 12 poles. Use a 2000μF oil condenser to magnetize 200
Pulse magnetization was performed at 0V. The surface magnetic flux density on the inner peripheral surface was measured with a Hall element.

For comparison, the known extruded rod manufactured in Example 1 was cut into a length of 20 mm and cut to have an outer diameter of 35.3 mm and an inner diameter of 2
A cylindrical billet (billet B) having a length of 9.1 mm and a length of 20 mm was produced. Using the same billet A as above, the same compression processing as described above was performed, and the billet was further cut in the same manner as described above, and then 12 poles were 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 the present invention was about 1.2 times that of the magnet produced for comparison.

Example 4 In the composition, 69.5% Mn, 29.3% Al, and 0.
5% C, 0.7% Ni and 0.1% Ti were melted and cast to prepare a cylindrical billet having an outer diameter of 45 mm, an inner diameter of 30 mm and a length of 20 mm. The billet was held at 1100 ° C. for 2 hours, then air-cooled to 600 ° C., held at 600 ° C. for 30 minutes, and then heat-treated to cool to room temperature.

Next, extrusion processing as shown in FIG. 1 was performed at a temperature of 720 ° C. through a lubricant. In Fig. 1, the outer diameter of the container part of the die is 45 mm, the inner diameter is 30 mm, the outer diameter of the bearing part is 30 mm, the inner diameter is 18 mm, and x is 20 mm.
Is. Billet after extrusion has an outer diameter of 30 mm and an inner diameter of 18
The length was 39 mm and the length was 39 mm. The billet after processing is cut and cut to have an outer diameter of 28 mm, an inner diameter of 19.6 mm and a length of 2
It was set to 0 mm (billet B).

Next, in the composition, 72% Mn, 27% Al and 1% C
Was melted and cast to prepare a cylindrical billet having a diameter of 55 mm and a length of 50 mm. The billet was held at 1150 ° C. for 2 hours, then cooled from 1150 ° C. to 700 ° C. at an average cooling rate of 20 ° C./min, held at 700 ° C. for 30 minutes, and then allowed to cool to room temperature.

Then, a known extrusion process up to a diameter of 35 mm was performed at a temperature of 720 ° C. through a lubricant. This extruded rod is 20 mm long
A cylindrical billet (billet A) having an outer diameter of 34 mm, an inner diameter of 28 mm, and a length of 20 mm was produced by cutting into pieces and cutting.

Next, the billet B is put in the hollow part of the billet A, and in a state shown in FIG. 3b, using a mold as shown in FIG. 3b, at a temperature of 680 ° C. via a lubricant. Compressed. In FIG. 3, the inner diameter of the die 3 is 40 mm.
The length of the cylindrical billet after processing is 10 mm.

The billet that has undergone this compression processing has an outer diameter of 39 mm and an inner diameter of 22.
After cutting to mm, the inner circumference was magnetized with 8 poles. Use a 2000 μF oil condenser to magnetize at 2000 V
It was pulse-magnetized. The surface magnetic flux density on the inner peripheral surface was measured with a Hall element.

For comparison, the known extruded rod manufactured in Example 1 was cut into a length of 20 mm and cut to have an outer diameter of 28 mm and an inner diameter of 19.
A cylindrical billet (billet B) having a length of 6 mm and a length of 20 mm was produced. Using the same billet A as above, the same compression processing as described above was performed, the billet was further cut in the same manner as described above, and then the inner circumference was magnetized with 8 poles to determine the surface magnetic flux density of the inner circumference surface of the Hall element. It was measured at.

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

Example 5 Mn, Al, C and Ni having the same composition as in Example 1 were melt-cast and a cylindrical billet having a diameter of 80 mm and a length of 40 mm was produced. The billet was held at 1100 ° C. for 2 hours and then heat-treated by allowing it to cool to room temperature.

Then, a known extrusion process up to a diameter of 50 mm was performed at a temperature of 720 ° C. through a lubricant. This extruded rod is 20
After cutting into mm, a cylindrical billet (billet X) having an outer diameter of 50 mm, an inner diameter of 35 mm and a length of 20 mm was cut. Also,
The extruded rod is cut into a length of 35 mm and cut to a diameter of 40
A cylindrical billet having a length of 35 mm and a length of 35 mm (billet Y) was used.
Using this billet Y, free compression processing was performed in the axial direction of the billet at a temperature of 680 ° C. via a lubricant. The length of the billet after processing was 20 mm. The billet (plane anisotropic magnet) after this processing was cut into a cylindrical billet (billet Y) having an outer diameter of 50 mm, an inner diameter of 35 mm and a length of 20 mm, similarly to the billet X. Next, the same extrusion processing and compression processing (two billet simultaneous compression processing) as in Example 1 were performed.
That is, the billet A and the billet B were extruded through a lubricant at a temperature of 680 ° C. using a die as shown in FIG. In Fig. 1, the outer diameter of the container part of the die is 50 mm, the inner diameter is 35 mm, the outer diameter of the bearing part is 36 mm, the inner diameter is 28 mm, and x is 20 mm.
Is. The billet after processing has an outer diameter of 36 mm, an inner diameter of 28 mm,
The length was 49.8 mm. Each billet after extrusion is cut and cut to have an outer diameter of 35.3 mm and an inner diameter of 29.1.
mm and length 20 mm. Next, the brass bar material was cut and cut into two cylindrical billets (billet A) having an outer diameter of 40 mm, an inner diameter of 35.3 mm, and a length of 20 mm. Next, the billets X and Y were put in the hollow portion of the billet A, and compression processing was performed at a temperature of 680 ° C. via a lubricant as in Example 1. In FIG. 3, the inner diameter of the die 3 is 40 mm. The length of the cylindrical billet after processing was 10 mm.

From the inner peripheral part of the billet after processing (the part corresponding to the billets X and Y before processing), a cubic sample having a side of 4 mm was cut out so that each side was along the radial direction, the chord direction and the axial direction, and the magnetic properties were measured. .

As for the magnetic characteristics, almost no difference was observed between the billets X and Y, and in the radial direction, Br = 6.2 kG and Hc = 3.0 kOe.
(BH) max = 6.8 MG · Oe, Br = in the chord direction
3.0 kG, Hc = 2.2 kOe, (BH) max =
1.8 MG · Oe, Br = 2.8 kG in axial direction, Hc
= 2.1 kOe. (BH) max = 1.6 MG · Oe. The magnet had excellent magnetic properties in the radial direction.

As described above, regarding the composition of the Mn-Al-C based magnet alloy, N
Only the i-added quaternary system and the Ni- and Ti-added quinary system are shown. However, a known ternary system which is a basic composition of the Mn-Al-C alloy magnet or a known additive element other than the above Regarding the multi-component system, although a slight difference was observed in the magnetic characteristics of the magnet after plastic working, the improvement in magnetic characteristics as described above was recognized by the known extrusion method.

The above embodiment is a typical example shown in FIG. 3, but billet A (9 in FIG. 3), billet B (10 in FIG. 3) and billet C (1 in FIG. 3).
The lengths of 1) do not necessarily have to be the same. For example, one billet may be slightly changed in length before and after processing. Instead of compressing the entire billet,
A method of compressing only a part of the billet may be used. In some cases, the billet A (or billet B) may be composed of two or more pieces. Further, a mandrel or the like may be used for the purpose of molding the inner peripheral surface.

EFFECTS OF THE INVENTION As described in the examples, according to the present invention, a hollow body-shaped billet made of a manganese-aluminum-carbon magnet alloy has a hollow cross-sectional shape of a hollow portion of a container portion at a temperature of 530 to 830 ° C. And, using a die in which the opening area of the container part is larger than the opening area of the bearing part, extrusion processing is performed by making the extrusion direction parallel to the axial direction of the billet,
After the hollow body-shaped billet is stretched in the axial direction and the circumferential direction by this extrusion process, the manganese-aluminum-carbon-based magnet alloy is further formed in the hollow portion of another hollow body-shaped billet made of a metal material. In the state where the hollow body-shaped billet after the extrusion processing is present, until the two billets come into contact with each other, or more, compression processing is performed in the axial direction of the hollow body-shaped billet made of the manganese-aluminum-carbon magnet alloy. A magnet exhibiting excellent magnetic properties when subjected to multi-pole magnetization even if the total plastic working amount is smaller than the above-described method of performing simultaneous compression working after performing the known extrusion processing by applying Is obtained.

[Brief description of drawings]

1A and 1B are partial cross-sectional views of a mold showing an example of the extrusion process of the present invention, and FIGS. 2A to 2D are partial cross-sectional views of a mold showing an example of the extrusion method of the present invention. 3A to 3E are sectional views of a part of a mold showing an example of the compression processing of the present invention. 1,1 '... Billet, 2 ... Mandrel, 3 ... Die, 4,5, Punch, 6 ... Container part, 7 ... Bearing part, 8 ... Conical part, 9,10,11 ... Billet.

Claims (6)

[Claims] 1. A hollow body-shaped billet made of a manganese-aluminum-carbon magnet alloy, having a hollow cross-sectional shape of a hollow portion of a container portion at a temperature of 530 to 830 ° C.,
Using a die whose opening area of the container part is larger than that of the bearing part, the billet is extruded in parallel with the axial direction and the extruding direction, and the hollow billet is extruded by the extruding process. In the hollow part of the other billet of a hollow body further made of a metal material, after the extruded billet of the hollow body made of the manganese-aluminum-carbon magnet alloy is present, A manganese-aluminum-carbon alloy magnet, characterized in that the two billets are in contact with each other, or more, in the axial direction of a hollow body-shaped billet made of the manganese-aluminum-carbon magnet alloy. Manufacturing method. 2. The method for producing a manganese-aluminum-carbon alloy magnet according to claim 1, wherein at least the inner peripheral portion of the other billet made of a metal material is made of a magnetic material. 3. A compression process is carried out in a state in which the outer circumference of the hollow-body-shaped billet made of the manganese-aluminum-carbon magnet alloy is restrained and at least a part of the inner circumference is free. A method for producing a manganese-aluminum-carbon alloy magnet according to claim 1. 4. A hollow body-shaped billet made of the manganese-aluminum-carbon magnet alloy is compressed in a state where at least a part of the outer circumference and the inner circumference is compressed, and then the outer circumference of the other billet. The method for producing a manganese-aluminum-carbon alloy magnet according to claim 1, wherein the manganese-aluminum-carbon alloy magnet is compressed in a state in which at least part of the inner circumference is free. 5. The method for producing a manganese-aluminum-carbon based alloy magnet according to claim 2, wherein the magnetic material is an isotropic manganese-aluminum-carbon based magnet alloy. 6. The method for producing a manganese-aluminum-carbon alloy magnet according to claim 1, wherein the hollow body is a cylindrical body.