JPS58206105A - Manufacture of manganese-aluminum-carbon alloy magnet - Google Patents

Abstract

PURPOSE:To provide a magnet suitable for multipole magnetization by a method wherein a part of a billet formed of polycrystalline Mn-Al-C alloy magnet undergoes the plastic deforming operation at 530-830 deg.C to impart a compressive strain in the easily magnetized direction. CONSTITUTION:A billet formed of polycrystalline Mn-Al-C alloy magnet undergoes the plastic deforming operation in a temperature range of 530-830 deg.C to impart a compressive strain not less than 0.05 in the absolute value of logarithmic strain in a direction parallel with the easily magnetized direction of the billet. The plastic deforming operation is performed by compressing a billet 1 on a lower die 4 with a punch comprising a movable punch 2 and a fixed punch 3. By so doing, there can attained a magnet in which a part of the billet has the anisotropic structure suitable for multipole magnetization and other part has the easily magnetized direction in one characteristic direction.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a permanent magnet 1. In more detail, rL, ρ crystalline manganese-aluminum-lamb-
Regarding the production of carbon-based (Mn-▲l-C-based) alloy magnets, it is customary to use an 8-pole magnetized Mn-▲l method.
-Mn--AI-C alloy fM ii is mainly a ferromagnetic phase, face-centered +l:)j crystal (τ phase, Llo type). It is composed of a regular lattice structure, h, C is a necessary structure of logs and L.
-C
It is known that there are 4 threads containing 371 threads and a small amount of additive elements, and
These Ig are called 1, this is Mn-A.
Manufacture of I-C threaded gold wire 1 θ, [1] In addition to casting and heat treatment, warm plastic processing such as push-open extrusion 1
In particular, the latter has excellent properties such as high magnetic properties, mechanical strength, weather resistance, and machinability. 3. A method for manufacturing Mn-▲l-C alloy magnets for multipolar magnetization.

In this case, a different hPl is applied to an anisotropic polycrystalline Mn-▲l-C thread alloy magnet using a known method such as an isotropic magnet, a compressor, or a warm extrusion process. The application of warm free compression to a force surface (combined compression method V) is known.

Compression processing has high magnetic ql in the radial direction.

Gender? ! }Although it is relatively thick l/shun+lI:・
A, K-4, non-uniform deformation may occur, and the existence of an undeformed zone is unavoidable.4.1. 1, a small compression strain results in a high magnetic property +/1 in all directions of the plane circle in the radial direction and the chordal direction 'L'.As mentioned above, in the compound addition 1' method, , the entire polycrystalline Mn-Muro c yarn alloy magnet with -axis ν direction is subjected to warm free compression processing in the anisotropic h'' direction, and the entire magnet 1 has a structure suitable for multi-polar magnetization as described above. 3. In the field of multipolar magnetism, the shape of magnets used is generally axially symmetrical, and the most commonly used shape is cylinder. Figures 1 and 2 show 1-circle magnets. Figure 1 shows the magnetic path inside the magnet (the broken line indicates Figure 2 is a schematic diagram of the formation of the inner) and 'i' with multi-pole magnetization, and Figure 1 shows the case where the In this specification, the magnetization shown in Fig. 2 is referred to as outer circumference magnetization, and the magnetization shown in Fig. 2 is referred to as inner circumference magnetization. Expressing the inner surface as the inner periphery 4 Puru 11 In Figures 1 and 2, there is a small V-shaped magnet, and if the magnet V is multi-pole magnetized, no magnetic path will pass through >4B. At least 741 through which the magnetic path passes (minutes are multipolar zi'i
(A structure suitable for ia will exhibit excellent magnetic properties when subjected to multipolar magnetization. Furthermore, in the above-mentioned conjugation processing method, before free compression processing, the structure is anisotropic in the direction of compression force. By applying free compressive force to the entire value I1, the magnetic body becomes multi-pole/? (Changes to a structure suitable for magnetism. For example, as an example of application, when applying multi-pole magnetization, the part where the magnetic path does not pass i'?l) is replaced by the above-mentioned uniaxial anisotropy. If it is set to 17, the end face of that part can be used effectively in cases where it is easy to use that part to detect rotation, etc.

The present inventors have developed a billet consisting of a polycrystalline Mn-Ml-C alloy magnet having an easy magnetization direction in one specific direction.
At a temperature of 30 to 830°C, a portion of the billet is subjected to an absolute value of logarithmic strain o in a direction parallel to the above-mentioned specific direction.
By performing plastic working that gives a compressive strain of 0.05 or more, the above problems can be resolved, and especially a) IL extension/(.

Zunawa Iha is a well-known Mn-Al-C alloy for magnetic alloy 1, for example, 68-73Φ:1;% (more than 7I in r1t l/c%
Mn and ('1oMn-6.e) ~(V3
An alloy consisting of Mn22,2)% C and the balance A/ is heated to 630 to 830" (by a known JJ method such as extrusion at a temperature of A polycrystalline Mn-4e-C alloy magnet having an easy magnetization direction or not can be attached to a billet made of M magnets with a hook parallel to the easy magnetization direction of the billet. By applying plastic working that produces a compressive strain of 0.05 or more than 1'fttJ with absolute logarithmic strain in the direction of ! What to do?-C 4. l+1-1” of said billet
■Front (compressive strain 4・lPX part) is suitable for multi-pole magnetization, +J, , ), magnetic structure 6 (7, other parts are 0 in specific -b direction, easy to make IR) J11'IJ6・I、Ts、Add the above plasticizer 1: Lid the structure of the previous magnet 1
(11. urari L:, h l-nod is the force (therefore, the absolute value of strain (111 is at least 0.06). As shown in the figure, the do-i-soto before plastic working is anisotropic in the direction of applying compressive strain, and magnetization is applied to the most suitable anisotropic structure (v(2)). 1 (This is because a compression dimension of 0.06 is required. 1. Kasa crystal Mn-A with easy magnetization direction 4.
7! - Part of the fin nod consisting of C thread alloy magnet v (2,
A compressive strain of 1. Eruyv
To explain some specific examples of processing, the first example and L7 are the billet shape 4 cylinder and C2/f in this case.
Figure 3 shows an example of VI Addition 1].
Y1! PI: ,Ull] is a smaller version of the two o'clock state, (2L) is +l: before, (b) is +]2 after /J.

In FIG. 3, Pireno I/21111J' can move in two directions. 3 is a fixing punch which, like punch 2, can be moved in the Z direction. 4 is a fixed lower mold.

After placing the billet 14 on the lower die 4, the punches 2 and 3 are moved in two directions (direction F in the figure) to approach the billet 1 (Lj), with the punch 2 facing downward in the figure. It is processed by moving it to (-). During processing, the punch 3 is identified so as not to move relative to the lower mold 4. In this way, the billet 1 is fixed and restrained by the punches 3 and 4, and only the outer periphery BB of the billet is compressed and pressurized by the punch 2 (b).
11, J=, 2 (7) (+l
As l and 7, II! Figure 4 shows an example of plastic deformation 1- when the shape of the billet is a cylinder.
IL) is the state before application of pressure (I isthmus is 11, (b) is 3° showing the state after application of pressure. In Figure 4, 1' is billet, 4
is l-1-IJ with fixed τ. 611 outside j~11
and is fixed to the lower mold 4. 6 can move in the Ho/Chi CZh direction.

After placing the billet 1 on the bottom mold 4, place the billet 1' into the outer mold 6. Sea urchin 7 outside '1151
)'I(" Figure (a) shows the state in which 1 is fixed at 4, then Bonde and 6 are moved in the Z direction (upward in the figure) and brought closer to Bishinode 1'. The billet 1 is thus fixed and restrained by the lower mold 4 and the outer mold 5), and only the inner periphery of the billet is compressed by the punch 6). ■: By doing so, the state shown in (b) is reached.In addition, the first
And the cylinder in the second example and the 1111 direction of the cylinder are parallel to the above-mentioned specific direction.

In the first example described above, only the outer periphery of the cylindrical billet was compressed, so only the outer periphery had an anisotropic structure suitable for polar magnetization. J': This is a magnet suitable for external magnetization. In the second example,
Because the syllables were compressed only on the inner circumference of the cylindrical billet, only the inner circumference had an anisotropic f1 structure suitable for multipolar magnetization, and the second
C/(This is a suitable magnet for applying the inner periphery magnetization as shown in the figure.

In the above example, a portion of the billet is divided into an outer circumference and an inner circumference.
2, but for special purposes it can be used.) i suitable for 1.
'tlS is fine. Also, compression 1 of tijl
There are two methods for compressing and pressurizing: one method is to perform compression pressurization continuously, and the other method is to perform it in multiple steps.

As a known technique, there is an example in which warm compression processing is applied to an axial prismatic magnet in the direction of axial force. The latter is also a uniaxially anisotropic prismatic magnet. According to the known technique, vL is about 60 to 70% when the direction of easy magnetization is changed in one direction -\.
7, and this 7'1- is approximately 0.9 to 1.21J1- as the absolute 111'1 of the logarithmic scale (I white is 1°, as mentioned above). Regarding the temperature range that can be applied to such plasticity/1 addition, in the temperature range of t-1, 630 to 830"C, the addition 1. was performed, or 11 at a temperature exceeding 780"C.
When magnetic, f1 was considerably lower than 7. Than'? ftL is -2 in the temperature range of 769 to 760°C.

Hereinafter, the present invention will be explained in detail by way of examples.

The composition was 69.5% (1) Mn, 29.3% Mul, 0.5% C1 and 0.7% Ni, melted and cast 1, a circle with a diameter of 7 mm and a length of 50 mm [ 1. Make a billet. This fillet was heated to a temperature of 110σ, held for 211.11 minutes, removed, and left to cool at room temperature.
? r-・ta. Next, extrusion was carried out to a diameter of 45 mm at a temperature of 720 (H) using a lubricant.
The extrusion process was performed up to 1.4 lines/1, and after cutting this extruded rod into lengths of 20 mm, cutting IJII LL was performed to make several cylindrical billets with an outer diameter of 31 mm, an inner diameter of 10 to 22 bars, and a length of 20 mm. I made one piece. The mold shown in Figure 4 is placed on this fillet and top once a month.
At a temperature of 680″C, the white strain θII is applied only to the inner circumference.
11 compressions were applied. In Figure 4: 1... and the outer diameter of Bocchi 6 is 26 strokes.

From the compressed part of the billet after processing, take out a cubic sample of about 6 mm on each side.
I measured it. Note that each side of the cube (r, [11+ direction,
Diameter) towards J and! I made it run parallel to the technique direction. ll
-Residual magnetic flux density (Br) for 1ti strain (Ez)
Figure 6 shows the changes in . As shown in Figure 5, 62 is 0.0
5, the Br in the radial direction becomes friendlier than the Br in the t-axis direction, and as Ez further increases, Br1l in the radial direction further increases. As can be seen from this figure, the change in the direction of easy magnetization from the axial direction to the radial direction progresses significantly in the range of Ez = 0.064. As shown in FIG. 5, compared to the known compression process, it exhibits high magnetic properties with a very small compressive strain.

After cutting the aforementioned extruded rod with a diameter of 31 MWI into a length of 20 #Iin, it was cut into a 680"C diameter using the mold shown in Fig. 3.
Compression processing was performed only on the outer periphery at 1'1A degree. Third
In the figure, the inner diameter of the punch 2 is 14 mm. A cubic sample of approximately 5 mm on a side was cut out from the compressed portion of the billet after pressurization in the same manner as described above, and its magnetic properties were measured. A
When I compared it with the same 6z model that had been subjected to the compression process described in Ill., there was no big difference between the two.

As described in Example V, the present invention provides a billet made of a polycrystalline Mn-J-C alloy magnet having an easy magnetization direction in a specific direction. The absolute value of the logarithmic strain in the horizontal direction is 0.05 or more.
A magnet having a structure suitable for polar magnetism is obtained by applying plastic working to give a compressive strain of (-). Still, since it has a cyanoscopic portion which is easily magnetized in one specific direction, that portion can be used for detecting rotation as described in 7 above.

The permanent magnet obtained by the present invention is a magnet suitable for high-performance multi-pole magnetization, and can be applied to many fields such as motors, generators, and meters.

[Brief explanation of drawings]

Figure 1 is a diagram schematically showing the formation of a magnetic path inside the magnet when the outer circumference of a cylindrical magnet is multipolar magnetized, and Figure 2 is a diagram showing the formation of a magnetic path inside the magnet when multipolar magnetization is applied to the inner circumference of a cylindrical magnet. FIGS. 3 and 4 are cross-sectional views of a part of a mold showing an example of plastic working of the present invention, and FIG. It is a figure which shows the change of the residual magnetic flux density Br with respect to the compressive strain of. 1.1... Billet, 2... Movable punch, 3... Fixed punch, 4... Lower mold, 5... Outside Type, 6...Movable punch.

Claims (1)

[Claims] A polycrystalline mankan with an easy magnetization direction in the -JJ direction of the bristles, - a fin made of a carbon-based alloy magnet, 630 to 830 ``C'/) +A-A degrees, +i
+tl 4 'I"F'
On the force plane parallel to the direction of til, the number of lights is out of sight (1
゛BIC0.06 or later 1. 2. Manufacturing method of aluminum-laminated carbon-based alloy wire 2.