JPS62247057A - Manufacture of manganese-aluminum-carbon alloy magnet - Google Patents

Abstract

PURPOSE:To obtain the titled alloy magnet which shows high magnetic properties when subjected to inside peripheral multipolar magnetization, by subjecting undermentioned two billets to compression working in the axial direction so that compressive strain of a hollow billet which is previously made anisotropic and also is allowed to exist in a hollow metallic billet is lower in the outside peripheral part than in the inside peripheral part. CONSTITUTION:The billet 1 composed of polycrystalline Mn-Al-C alloy magnet which is previously made anisotropic is allowed to exist in the hollow part of the above-mentioned primary billet 2 composed of metallic material. In the above state, axial-direction compression working then is applied to both billets at 530-830 deg.C until the billets 1, 2 come into contact with each other or further extent by the use of punches 4, 5 whose surfaces (punching surfaces) to be in contact with the billets 1, 2, respectively, are severally inclined planes. At this time, respective heights of the billets 1, 2 after working are greater in their outside peripheral parts than in their inside peripheral parts, respectively, so that respective compressive strains of the billets 1, 2 are lower in their outside peripherals parts than in their inside peripherals parts, respectively. As a result, an Mn-Al-C alloy magnet having diameter-direction magnetic properties higher than those of the one obtained by the conventional method based on the same amount of compressive strain can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method of manufacturing permanent magnets, particularly polycrystalline manganese-aluminum-charcoal! The present invention relates to a method of manufacturing a high-performance Mn-M1-1 alloy magnet for multipolar magnetization using a (Mn-M1-C) alloy magnet.

Conventional technology Mn-1-C alloy magnets are mainly composed of a face-centered tetragonal (τ phase, Ll. regular lattice) structure, which is a ferromagnetic phase, and contain C as an essential constituent element. , ternary alloy magnets containing no additive elements other than impurities, and quaternary or higher multi-component alloy magnets containing a small amount of additive elements are known, and these are collectively referred to as magnets.

As for the manufacturing method, there are known methods including plastic working steps such as extrusion processing in addition to those using casting and heat treatment. In particular, the latter method is known as a method for producing anisotropic magnets having excellent properties such as high magnetic properties, mechanical strength, weather resistance, and machinability.

Further, as a method for producing a multi-polar magnetized alloy magnet using a Mn-1-C alloy magnet, isotropic magnet compression processing is used (% Permit No. 1011473).

Uniaxially anisotropic polycrystalline Mn obtained by a known method such as extrusion
-M 1-c alloy magnets subjected to free compression processing in the anisotropic direction (the obtained magnets are referred to as planar anisotropic magnets. Japanese Patent Application Laid-open No. 119762/1983), and hollow ones made of metal materials. The two billets are in contact with each other in a state where a second billet in the form of a hollow body made of a polycrystalline Mn-1-C alloy magnet that has been made anisotropic in advance is present in the hollow portion of the first billet in the form of a body. up to or more than 1st. A method in which compression processing is performed in the axial direction of the second billet (referred to as a two-billet simultaneous compression processing method. Japanese Patent Application Laid-Open No. 60-59720)
It has been known.

Problems to be Solved by the Invention The above-mentioned two billet simultaneous compression method
No. 720), that is, in the hollow portion of a hollow first billet made of a metal material.

In the presence of a second billet in the form of a hollow body made of a polycrystalline Mn-1-C alloy magnet that has been made anisotropic in advance, until the two billets come into contact or beyond,
A method in which the billet is compressed in the axial direction produces a magnet that is desirable for internal multi-pole magnetization.

Means for Solving the Problems The present invention provides a hollow body made of a polycrystalline Mn-Ml-C alloy magnet which has been made anisotropic in advance, in the hollow portion of a first hollow billet made of a metal material. In the state where the second billet having the shape of a hollow body is present, the compressive strain at the outer peripheral part of the second billet having the hollow body shape is smaller than the compressive strain at the inner peripheral part until the two billets touch or more. , a hollow body-shaped first . Compression processing is performed in the axial direction of the second billet.

Effect: By the above-mentioned method, that is, when two billets are simultaneously compressed, the second billet made of Mn-1-C alloy magnet is compressed so that the compressive strain on the outer circumference is smaller than the compressive strain on the inner circumference. By applying this method, the magnetic properties in the radial direction inside the magnet are improved even with the same amount of compressive strain as in the conventional known method, and a magnet that exhibits high magnetic properties when subjected to inner circumferential multi-pole magnetization can be obtained. I can do it.

Embodiment The present invention provides a hollow portion of a first hollow billet made of a metal material, and a second hollow billet made of a polycrystalline Mn-1-C alloy magnet which has been made anisotropic in advance. In the presence of The hollow body-shaped first . Compression processing is performed in the axial direction of the second billet.

Most of the manufacturing method of the present invention is based on the above-mentioned known technology (Japanese Unexamined Patent Publication No. 6
0-59720).

In the compression processing of the known technique, a hollow part of a first hollow billet made of a metal material is injected into a second hollow part made of a polycrystalline Mn-1-C alloy magnet which has been made anisotropic in advance. of the first billet is present until the two billets touch or more. Compression processing is performed in the axial direction of the second billet.

On the other hand, in the compression processing of the present invention, after the above-mentioned compression processing, the second billet made of the Mn-1-C alloy magnet is processed so that the compressive strain at the outer circumference is smaller than the compressive strain at the inner circumference. , 1st. Compression processing is performed in the axial direction of the second billet.

Similar to the above-mentioned known technology, when the billet is made of a polycrystalline Mn-I-0 alloy magnet (-axis anisotropic magnet) having an easy magnetization direction in the axial direction of the hollow body, during compression processing, The compressive strain must be 0.03 or more in terms of the absolute value of the logarithmic strain. This is because the billet before compression processing is anisotropic in the direction of applying compressive strain, and the change in structure that exhibits high magnetic properties in multipole magnetization is at least 0.03.
This is because a compressive strain of .

As an example of the above-mentioned compression processing, the hollow first billet made of a metal material is made into a cylindrical shape, and the polycrystalline Mn-
The shape of the hollow body-like second billet made of a Mt-C alloy magnet is also a cylindrical body, and some examples will be described below.

First, some specific examples of the first method will be explained.

FIG. 1 shows a cross section before processing. 1 is a second billet (a billet made of a polycrystalline Mn-1-C alloy magnet which has been made anisotropic in advance).

2 is the first billet (billet made of metal material) 3 is the third billet (billet made of metal material), 4.5
is the punch, and 6 is the outer mold. As shown in FIG. 1, the difference from the prior art is that the surfaces (punch end surfaces) of the punches 4 and 6 that come into contact with the billets 1 to 3 are not flat surfaces but sloped surfaces. This punch 4 and punch 5
The billets 1 to 3 are compressed in the axial direction by applying pressure in the axial direction of the billets 1 to 3. 1st
In the figure, a first billet 2 and a second billet 1
The height before processing is the same. Billets 1-3 after processing
The height of the outer periphery is greater than the height of the inner periphery, and compression processing is performed in the axial direction of billets 1 to 3 so that the compressive strain on the outer periphery of billets 1 to 3 is smaller than the compressive strain on the inner periphery. This means that Compressive strain refers to billets 1 to 3.
This refers to the strain in the axial direction.

Next, another typical compression processing example of the present invention will be described assuming that the cross-sectional shape of the billet is ring-shaped. FIG. 2 shows a cross-section of the billet before processing, similar to FIG. 1. As shown in FIG. 2, the difference from FIG. 1 is that the punch end faces of the punches 4 and 6 are flat.

The height of the outer periphery of the second billet 1 before processing is smaller than the height of the inner periphery. The billet after processing has a substantially cylindrical shape, and the height of the outer circumferential portion of the billet and the height of the inner circumferential portion of the billet are approximately the same. In this case as well, the second billet 1 is compressed in the axial direction so that the compressive strain on the outer circumferential portion of the second billet 1 is smaller than the compressive strain on the inner circumferential portion.

As described above, one aspect of the present invention is the above-mentioned known technology (Japanese Unexamined Patent Publication No. 6
This is almost the same as the compression process shown in Japanese Patent Publication No. 0-59720, but by making the end face of the second billet 1 an inclined surface or the end faces of the punches 4 and 5 into inclined surfaces, the simultaneous compression process of the two billets can be performed. The second billet 1 can be compressed in the axial direction so that the compressive strain on the outer circumference of the second billet 1 is smaller than the compressive strain on the inner circumference. The magnetic properties of the direction become higher.

Even in a combination of the above two examples, the second billet 1 can be compressed in the axial direction so that the compressive strain on the outer circumferential portion of the second billet 1 is smaller than the compressive strain on the inner circumferential portion. That is, for example, using a mold consisting of the punches 4 and 5 and the outer mold 6 shown in FIG. 1<tl),
This is a method of compressing the second billet 1 shown in FIG.

In the above example, the punch 4.6 end face or billet 1
The WA surface is an inclined surface, but there are other reeds such as stepped surfaces (stepped shapes), 1000 sloped surfaces, or a combination of more than 10 sloped surfaces.
Furthermore, the punch or billet end face to be made uneven may be on both sides or on one side. What is necessary is to compress the second billet 1 in the axial direction so that the compressive strain on the outer circumferential portion of the second billet 1 is smaller than the compressive strain on the inner circumferential portion. As a result, the magnetic properties in the radial direction are improved even with the same amount of compressive strain as in the known technology.

Regarding the possible temperature range of compression processing as mentioned above,
, in the temperature range of 530-830''C.

Although processing was possible, the magnetic properties deteriorated slightly at temperatures exceeding 780"C. The most desirable temperature range is 5.
The temperature was 60-760°C.

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

Example 1 (Figure 2a) The blend composition is 69.5% Mum and 29.3% Mul.

Melt and cast 0.5% C and 0.7% N1, diameter 6
A cylindrical billet with a length of 401 flll was produced.

After holding this billet at 1100°C for 2 hours.

Heat treatment was performed by allowing the sample to cool to room temperature.

Next, extrusion processing was performed at a temperature of 720"C using a lubricant. The billet after processing had a diameter of 40 cm.

It was 90m long. This extruded rod was cut and machined to have an outer diameter of 35 mm, an inner diameter of 29 mm, and an outer circumference length of 2 mm.
A second billet 1 with an inner circumferential length of 30 m and both end faces having sloped surfaces was prepared. Furthermore, we cut and machined the brass bar material to have an outer diameter of 40mm, an inner diameter of 36cm, and a length of 3oI.
The first biL/+7 cylindrical III+ cylinder was fabricated.

Next, the second billet 1 is put into the hollow part of the first billet 2, and the second billet 1 is placed in the hollow part of the first billet 2, and is heated through a lubricant at a temperature of
Compression processing as shown in a) was performed. In FIG. 2 (&), the inner diameter of the outer mold 6 is 4° true. The length of billet 1.2 after processing was 161 mm.

The processed billets 1 and 2 were cut to an inner diameter of 20 rtaa, and then the inner circumferential surface was magnetized with 24 poles.

Magnetization uses a 2000μF oil capacitor.

Pulse magnetization was performed at 1500V. The surface magnetic flux density on the inner peripheral surface was measured using a Hall element.

For comparison, the extruded rod described above was cut and machined to form a second cylinder with an outer diameter of 36 mm, an inner diameter of 29 mm, and a length of 26 mm.
A billet was prepared. Using the second billet and the first billet having a length of 26 pieces, compression processing was performed in the same manner as described above until the length was 15 pieces. Furthermore, after cutting in the same manner as above, 5 magnetizations were performed and 1 surface magnetic flux density was measured.

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.

Example 2 (Fig. 2b) Made of pure iron bar material with an outer diameter of 40 mg, an inner diameter of 35 mm, and a length of 30 mm.
A first billet 2 having a cylindrical size of mm was produced.

A second billet 1 (same as in Example 1) was put into the hollow part of the billet 2, and the second billet 1 was heated at a temperature of 680°C via a lubricant.
Compression processing as shown in Figure (a) was performed.

In FIG. 2 [ex.], the inner diameter of the outer mold 6 is 40 mm.

The height of billet 1.2 after processing was 15mm.

After cutting the processed billet to an inner diameter of 22 circles, the inner circumference was magnetized with 24 poles in the same manner as in Example 1.

The surface magnetic flux density was measured.

For comparison, the second billet 1 produced for comparison in Example 1 and the same first billet 2 as described above having a length of 26 were prepared.
After compression processing and cutting were carried out in the same manner as described above, the inner circumference was magnetized.

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.

Example 3 Using a bar of electromagnetic soft iron, the outer diameter is 4011119 and the inner diameter is 35.
+10111 A second cylindrical billet 1 with a length of 30 m was filled with the same material as in the production lot 1 (Example 1), and was heated with es via lubricant.
Compression processing as shown in FIG. 2(a) was performed at a temperature of o'c. In Fig. 2(a), the inner diameter of the outer mold 6 is 40 m.
It is m. The height of the billet after processing was 15 mm.

After cutting the processed billet to an inner diameter of 22 mm.

As in Example 1, 24 poles were magnetized on the inner periphery, and the surface magnetic flux density was measured.

For comparison, the second billet produced for comparison in Example 1 and the same first billet 2 having a length of 261 m as described above were used.
After compression processing and cutting in the same way using
It was magnetized with 4 poles.

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.

Example 4 (Figure 2 C) The blending composition was 69.4% Mn, 29.3% Mn1°,
0.5%00, 0.7% Ni and 0.1%(7)Ti
A cylindrical billet having a diameter of SOW and a length of 40+a was produced by melting and casting. This billet was subjected to the same heat treatment as in Example 1. Next, extrusion processing was performed at a temperature of 720°C.

The billet after processing had a diameter of 32 mm and a length of 98 mm. This extruded rod was cut and machined to have an outer diameter of 281 mm.
1111. Inner diameter 2011111 e Length of outer periphery 20
A second billet 1 with an inner circumference length of 30+m and an inclined end surface was produced.

Next, the blended composition was 72% Mn, 27% Mn, and 1% Mn.
A cylindrical billet with a diameter of 65 mm and a length of 50 mm was prepared by melting and casting C. After holding at 1160°C for 2 hours,
Too "C" from 0℃! The sample was cooled at an average cooling rate of 20° C./min, held at 700° C. for 30 minutes, and then heat-treated by allowing it to cool to room temperature.

Then, through lubricant, at a temperature of 720 ° C, the diameter of 35
Extrusion processing was performed up to the throat. This extruded rod was cut and processed to have an outer diameter of 3411 mm! II, inner diameter 28mm, length 30ra
A first billet 2 having a cylindrical shape of s was produced.

Put the second billet 1 into the hollow part of the first billet 2,
Compression processing as shown in FIG. 2(C) was performed at a temperature of 680° C. using a lubricant. The inner diameter of the outer mold 6 is 40mm. The length of the cylindrical billet after processing was 16 mm.

After cutting the processed billets 1 and 2 to have an inner diameter of 22 mm, the inner circumference was magnetized with 24 poles in the same manner as in Example 1, and the surface magnetic flux density was measured.

For comparison, the extruded rod with a diameter of 32 mm was cut,
After cutting, the outer diameter is 281. Inner diameter 20 fl.

A second cylindrical billet 1 with a length of 25 m was produced.

Using the same first billet 2 with a length of 25 mm as described above, compression processing was performed in the same manner as above, and after further cutting processing,
24 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 this example was about 1.2 times that of the magnet produced for comparison.

Example 6 Mn with the same blending composition as Example 1, Mu1. C and N1
was melted and cast to produce a cylindrical billet with a diameter of 80 m and a length of 40 mm. This billet was subjected to the same heat treatment as in Example 1. Extrusion processing up to a diameter of 60 mm was carried out at a temperature of 720° C. via a lubricant. The extruded rod was cut and machined to produce a fourth billet having an outer diameter of 38 m, an inner diameter of 291 rrln + a length of the outer periphery of 20 rIC≠, and a 30-fold end face with an inclined surface.

Furthermore, the extruded rod was cut and machined to a diameter of 35 rl.
A billet with rm e length of 40a was produced. Free compression processing was performed at a temperature of 660° C. through a lubricant. The length of the billet after processing was 30+m.

After processing, the billet (planar anisotropic magnet) is cut into an outer diameter of 35 m, an inner diameter of 29 m, and a length of the outer circumference of 201 rr.
A sixth billet with an inner circumferential length of 30 wm and an inclined end surface was prepared.

Next, the brass bar was cut and machined to an outer diameter of 40 F.
M+ e Two cylindrical first billets 2 with an inner diameter of 35 al and a length of 30 m were prepared, and a fourth billet or a fifth billet was placed in the hollow part of each billet 2.

As in Example 1, compression processing was performed at a temperature of 680° C. using a lubricant. The inner diameter of the outer diameter 6 is 40wll1. The length of the cylindrical billet after processing was 1,511,111 mm.

After cutting the processed billet to an inner diameter of 20 mm, the inner circumference was magnetized with 24 poles in the same manner as in Example 1, and the surface magnetic flux density was measured.

For comparison, the extruded rod mentioned above was cut and machined,
A second cylindrical billet having an outer diameter of 35 mm, an inner diameter of 29 mm, and a length of 25 mm was prepared. This second billet and length 25rm
With the first billet of.

In the same manner as above, compression processing was performed up to 15 lengths, and after cutting, magnetization was performed, and the surface magnetic flux density was measured.

Comparing the above two values, the value of the surface magnetic flux density of the magnet obtained by the method of this example is the fourth. No difference was observed between the 5th billet and the magnet made for comparison.
．． It was twice that amount.

Example 6 (Fig. 1b) The extruded rod produced in Example 1 was cut and machined to form a second cylinder with an outer diameter of 35'ml + an inner diameter of 29mm and a length of 20mm.
From the billet 1 and brass bar material, the outer diameter is 4o and the inner diameter is 3.
A cylindrical first billet 2 having a length of 5+m and a length of 20 meters was produced. The second billet 1 is put into the hollow part of the first billet 2, and the first billet 1 is heated at a temperature of 680°C via a lubricant.
Compression processing was performed as shown in Figure 3). The inner diameter of the outer mold 6 is 40 mm.

The inclination angle (- is 1 dO, and the height of the outer circumference of billets 1 and 2 after processing was 15 liao.

After cutting the processed billet 1.2 to an inner diameter of 26 mm, the inner circumference was magnetized with 24 poles in the same manner as in Example 1, and the surface magnetic flux density was measured.

For comparison, the same billet 1.2 as above was compressed using the punches 4 and 5 shown in Fig. 2 and a mold with an outer diameter of 6, and then the billet was processed in the same manner as above. After cutting, the inner circumference was magnetized with 24 poles.

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.

The above embodiments are typical examples shown in FIGS. 1 and 2, but the lengths of the second billet 1, first billet 2, and third billet 3 do not necessarily have to be the same. There isn't. For example, one fin may be used. Furthermore, instead of compressing the entire billet, only a portion of the billet may be compressed. In some cases, the second billet 1 (or billet 2.3) may be divided into two or more parts. Further, a mandrel or the like may be used for the purpose of molding the inner peripheral surface.

Regarding the composition of the Mn-Ml-C alloy magnet, only the quaternary system with Ni addition and the quinary system with Ni and Ti additions are shown, but the basic composition of the Mn-Ml-C alloy magnet is Although some differences were observed in the magnetic properties of the magnets for certain ternary systems, the above-mentioned improvement in the magnetic properties was observed compared to the known compression processing method.

An example was shown in which a uniaxial anisotropic magnet or a plane anisotropic magnet was used as the Mn-mu 1-C alloy magnet which had been made anisotropic in advance, but the same results could be obtained by using a radially anisotropic magnet or the like.

Furthermore, regarding the shapes of the billet 1 and punch 4.5 end faces, an example of an inclined surface was shown, but it was also observed that the magnetic properties were improved compared to conventional compression processing even when the end faces were stepped.

Effects of the Invention The present invention, as described in the embodiments, consists of a polycrystalline Mn-Ml-C alloy magnet which has been made anisotropic in advance, and is placed in the hollow portion of the first billet in the form of a hollow body made of a metallic material. In the state where the hollow body-shaped second billet exists, the compressive strain at the outer peripheral part of the hollow body-shaped second billet is smaller than the compressive strain at the inner peripheral part until the two billets touch or By applying compression processing in the axial direction of at least the second billet in the form of a hollow body, a magnet that exhibits high magnetic properties when subjected to internal multi-pole magnetization is obtained. By this method, Compared to conventional methods, the magnetic properties in the radial direction are improved even with the same amount of compressive strain.

[Brief explanation of drawings]

Figures 1 and 2 are cross-sectional views of embodiments of the present invention.
...Second billet, 2...First billet. 3...Third billet, 4,6...Punch, 6...External mold, α...Inclination angle.

Claims (9)

[Claims] (1) A state in which a second hollow billet made of a polycrystalline manganese-aluminum-carbon alloy magnet that has been made anisotropic in advance exists in the hollow part of a first hollow billet made of a metal material. At a temperature of 530 to 830°C, the compressive strain at the outer circumference of the hollow second billet made of the previously anisotropic polycrystalline manganese-aluminum-carbon alloy magnet becomes the compressive strain at the inner circumference. A manganese-aluminum-carbon alloy magnet in which the hollow body-shaped first and second billets are compressed in the axial direction until the first and second billets come into contact with each other or more so as to become smaller. manufacturing method. (2) A hollow first billet made of a metal material,
Claim 1 in which at least the inner peripheral portion is made of a magnetic material
A method for producing a manganese-aluminum-carbon alloy magnet as described in 2. (3) A second billet in the form of a hollow body made of a polycrystalline manganese-aluminum-carbon alloy magnet that has been anisotropically made in advance is a polycrystalline manganese-aluminum-carbon alloy magnet that has an easy magnetization direction in the axial direction of the hollow body. 3. The method for manufacturing a manganese-aluminum-carbon alloy magnet according to claim 1 or 2, wherein the magnet is made of an alloy magnet, and the compressive strain is 0.03 or more as an absolute value of logarithmic strain. (4) A second billet in the shape of a hollow body made of a polycrystalline manganese-aluminum-carbon alloy magnet that has been anisotropically made in advance has an easy magnetization direction parallel to a plane perpendicular to the axial direction of the hollow body, Moreover, the patent claim comprises a polycrystalline manganese-aluminum-carbon alloy magnet that is magnetically isotropic within the plane and anisotropic within a plane that includes the axial direction and a straight line parallel to the plane. Range 1st or 2nd
A method for producing a manganese-aluminum-carbon alloy magnet as described in 2. (5) A hollow second billet made of a polycrystalline manganese-aluminum-carbon alloy magnet which has been made anisotropic in advance is made of a polycrystalline manganese-aluminum-carbon alloy magnet having an easy magnetization direction in the radial direction. Manganese-aluminum- as claimed in claim 1 or 2
Manufacturing method for carbon-based alloy magnets. (6) The compression process is performed while the outer periphery of the hollow second billet made of the previously anisotropic polycrystalline manganese-aluminum-carbon alloy magnet is constrained, and at least a portion of the inner periphery is free. A method for manufacturing a manganese-aluminum-carbon alloy magnet according to claim 1 or 2, which is carried out in a state where (7) The compression process was performed with at least a portion of the outer periphery and inner periphery of the hollow first billet made of the previously anisotropic polycrystalline manganese-aluminum-carbon alloy magnet freed. After that, the manganese-aluminum-carbon according to claim 1 or 2 is further carried out with the outer periphery of the first billet restrained and with at least a part of the inner periphery free. Manufacturing method for alloy magnets. (8) The method for manufacturing a manganese-aluminum-carbon alloy magnet according to claim 2, wherein the magnetic material is an isotropic manganese-aluminum-carbon alloy magnet. (9) The method for producing a manganese-aluminum-carbon alloy magnet according to claim 1 or 2, wherein the hollow body is cylindrical.