JPS61239608A - Anisotropic magnet and manufacture thereof - Google Patents

Abstract

PURPOSE:To easily obtain anisotropic magnetic characteristics as well as to manufacture the magnet to be used in the magnetic circuit such as a magnetron, a speaker and the like by a method wherein a press work is performed in such a manner that the density of magnetic flux on one punch surface is made higher than that of the other punch surface by adding magnetic field in molding space in the direction of compression. CONSTITUTION:Magnetic powder 4 is filled in the space formed by the dies 1 made of a non-magnetic material or the material having low permeability, the upper punch 2 and the lower punch 3, at least a part or more of which is made of ferromagnetic material. A coil 5, on which a magnetic field 6 is applied in the direction as shown by the arrow in the diagram, is arranged in the above-mentioned magnetic space. Magnetic space is formed in such a manner that the magnetic flux density on the surface of one punch 3 is made higher than the magnetic flux density on the surface of the other punch 2, and a press work is performed by adding magnetic field to the magnetic space in the direction of compression. An anisotropic magnet having excellent anisotropic characteristics can be manufactured easily by performing the above- mentioned processing method.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an anisotropic magnet, particularly an anisotropic magnet formed by press-molding magnetic powder in a specific magnetic field, and a method for manufacturing the same.

(Conventional technology) R1Co5 alloy (where R is a rare earth element).

and I (2COI7 alloys containing Fe, Cu, Ti, Zl, Hf, and the recently invented R-B
-Fe-based alloy (see JP-A-59-46.00B)
Anisotropic magnets are made by finely pulverizing magnetic powder such as 1 to 50 μm (average particle size), press-forming in a predetermined magnetic field, and sintering and heat-treating as necessary. Widely used in other electrical equipment.

As shown in Fig. 6 (see Japanese Patent Publication No. 60-931), this type of magnet consists of a die 1 made of a non-magnetic material or a material with low magnetic permeability, and an upper punch 2 made of a ferromagnetic material. Then, the molding space formed by the lower punch 3 is filled with magnetic powder 4, and a magnetic field 6 is applied in the direction of the arrow by a coil 5 located at the same level as the molding space, and press molding is performed.
・.

It is manufactured by sintering and heat treating.

(Problems to be solved by the invention) However, as shown in Figure 6, it is one of the same sex and made of the same material.

As shown in FIG. 3, the 1° magnet 41 made by the conventional method using the lower bunch has surface magnetic flux densities of approximately the same level on the A side and the 3rd side. There may be cases where the magnet used in a particular magnetic circuit is inappropriate. In other words, as disclosed in Japanese Patent Publication No. 53-47919, it is disadvantageous for magnets used in magnetic circuits such as magnetrons, speakers, and motors that utilize the fact that one magnetic pole end surface is more ferromagnetic than the other magnetic pole end surface. There are cases where

It is an object of the present invention to solve the above-mentioned problems of the prior art and to provide an anisotropic magnet in which the characteristics of one magnetic pole end face are higher than the characteristics of the other magnetic pole end face, and a method for manufacturing the same. .

(Means for Solving the Problems) The present invention provides magnetic powder (e.g. RICO5 alloy powder, R2C017 alloy powder, R-'B-Fe alloy powder) are filled and formed, so that the magnetic flux density on one punch surface is higher than that on the other punch surface. This method is characterized by applying a magnetic field in the compression direction to the molding space to perform press molding.

(Function) The present invention will be described in detail below.The magnet of the present invention is manufactured by the pressing method shown in Fig. 1゜1 or Fig. 2.
As shown in the figure, it is anisotropic in the compression direction, and the magnetic properties of the magnet end face B are better than those of other 1riiA.

In Figures 1 and 2, finely ground magnetic powder (
For example RICOs, R)Co17 and R-B-
Fe-based alloy powder) 4 is diced into 1. The forming space formed by the upper punch 2 and the lower bunch 3 is filled, a magnetic field 6 is applied in the direction of the arrow by a coil 5 located at the same level as the forming space, press forming is performed, and sintering and heat treatment are performed as necessary. I do. This is because if the die 1 is not made of a non-magnetic material or a material with low magnetic permeability, the amount of effective magnetic flux in the molding space will decrease and the magnetic properties will deteriorate. The upper and lower punches must be at least partially made of ferromagnetic material by 1° in order to guide the magnetic flux, and may have a shape in which the upper punch is not inserted into the molding space (Fig. 1).

In Figure 1, if both the upper and lower punches are made of the same ferromagnetic material, and if the area of the upper punch surface is Su and the area of the lower bunch surface is SL, then the magnetic flux density of the lower punch surface 1 is the same as that of the upper punch surface. Compared to that, the magnetic pole B on the lower punch surface side becomes ferromagnetic compared to A, which is S U / S L times larger.

FIG. 2 shows an upper bunch 2 made of ferromagnetic material inserted into the molding space, and a lower bunch 6 made of a ferromagnetic material made of the same material as the upper bunch, with the punch outer peripheral part 61 made of a non-magnetic material or weakly magnetic material. This is the case when inserted into the molding space.

In FIG. 2, as in FIG. 1, the magnetic flux density on the lower bunch surface increases compared to that on the upper punch surface, and as a result, the magnetic pole B on the lower punch surface side becomes ferromagnetic 10 compared to A. can get. Also inside the molding space.

Even if a core pin of non-magnetic material or low magnetic permeability is installed, the effect of the invention will not be lost; here, the core pin is a cylindrical rod, a square rod, etc., and by inserting it, It is used for the purpose of forming holes, four parts, or non-magnetic material or parts with low magnetic permeability in a molded body. The shape of the core pin has no bearing on the existence or infancy of the present invention. Further, the present invention provides a magnet.1. The cross section viewed from the anisotropic direction may have any shape, and furthermore, the present invention can be applied to a magnet (a cylindrical magnet divided) whose cross section viewed parallel to the volitional direction is circular.

As mentioned above, press-formed magnets are heat-treated and magnetized as necessary after sintering, but during press-forming, there is no porosity in the magnetic powder.
i) If a binder such as C1l, plastic, or rubber is mixed, sintering is not required. The desired average particle size of the magnetic powder used in the present invention is 1-10 μm for J'i+COs type rare earth CO, 2-50 μm for 1°f<vco+t type rare earth Co, and 1-10 μm for R-B-Fe magnet. This is preferable for obtaining magnetic properties.

The strength of the magnetic field applied during press molding is preferably 5 KOe or more, and the molding pressure is preferably 1 to 10 t/7.

In addition, sintering after molding is performed in vacuum, inert gas, 1
In a non-oxidizing atmosphere such as a reducing gas, rare earth cobalt magnets have a temperature of 1100-1250°0. For R-B-Fe magnets, it is sufficient to heat and hold at 900 to 1200'o for at least 0.5 hour and then cool.

(Examples) Next, the present invention will be described in detail, but the following examples do not limit the present invention.

Example 1 An alloy powder with an average particle size of 6.4 μm having a composition of 66% Br and residual CO was pressed using the same pressing method and the same compacting pressure and the same magnetic field as shown in FIG. 6 (comparative example) and FIG. 1 (example). Molded using magnetomotive force. The obtained molded body was sintered with Ar gas at 1140'0XIHr, and then 1.・950'(
After treatment with lX1f(r), cool to 800'0 at a rate of 1.5'o/min and quench in oil from soo'o.

A test material of X30X10 (10 directions are anisotropy directions) was prepared. The obtained magnet 41 is assembled into a U-shaped yoke (8841') 21 with external dimensions of 60 x 50' x 40''l and a wall thickness of 10 m as shown in Figs.
Table 1 shows the results of measuring the air gap magnetic flux density Bf at m.

Note that the die 1 in FIG. 6 is made of a non-magnetic material, and the upper and lower bunches 2 and 3 are 845G 36-sided square binding 5.

The die 1 and the lower bunch 5 in FIG. 1 are the same as those in FIG. 6, and only the upper bunch 2 has a 45-square shape of 545c. The magnet obtained by the method shown in FIG. 1 was arranged so that the ferromagnetic surface on the lower punch side was on the gap side of the yoke.

Table 1 As can be seen from Table 1, Bf was improved by 996 to 4150G by arranging the ferromagnetic surface on the air gap side.

Example 2 Weight ratio: 25% Sm1 [3% Pe 4% ct12%
Average particle size 6 with a composition of Zr balance ICO! As in Example 1, the alloy powder of .mu.m was molded using the pressing method shown in FIGS. 6 and 1. The obtained molded body was sintered in H2 gas at 1200° x 2 Hr, then cooled in a furnace and further 117
After 0°0x6Hr generalization treatment and rapid cooling, 800
After the treatment (°OX3.0Hr), it was slowly cooled to room temperature at a cooling rate of 1°0/min, and the magnetic properties were evaluated.

The evaluation method and magnet shape are the same as in Example 1. In addition, regarding the magnet obtained by the method shown in FIG. 1, the ferromagnetic surface was arranged so as to be on the air gap side of the yoke. The results are shown in Table 2.

Table 2 As shown in Table 2, by providing a ferromagnetic surface on the air gap side, B111 improves by 6 coefficients from 425o to 4500G, resulting in a composition of Example 61 with a molar ratio of Nd(FeO,9Bo,1) of 5.54. An alloy powder having an average particle size of 3.8 μm was pressed using the pressing method shown in FIG. 6 and FIG.

- magnetic field magnetomotive force). Obtained molded body
□10″7orr in vacuum 11ooυX2Hr
After sintering, the sample was cooled in a furnace, and then treated at 620°tl x 2 hours, rapidly cooled, and subjected to evaluation of magnetic properties. Note that the method in FIG. 6 is the same as in Example 1, but in FIG.
The die 1 and the upper bunch 2 were the same as in Example 1, and only the lower bunch 6 was changed. The lower punch 6 in FIG. 2 has a 66 seed square shape, the outer peripheral part 61 is made of non-magnetic carbide with a thickness of 5 cm, and the internal 26M square column part is made of 545c. Furthermore, the fourth
The magnets obtained in Figures 5 and 5 were arranged so that the ferromagnetic surface was on the gap side of the yoke. The results are shown in Table 51
．． 1. According to the present invention, Bf is improved by about 7% to 4750
It became G.

Table 3 4 Note that the shape of the molded body is not limited to the shape shown in FIG. 3, and it goes without saying that a core pin of any shape may be used as described above.

In other words, the cross section viewed from the anisotropic direction may have any shape, and the upper and lower punch surfaces do not need to be limited to flat surfaces.
The present invention can also be applied to arc-shaped magnets obtained by disassembling cylindrical magnets.

Further, by moving the magnetic field generating coil to the punch side of the desired ferromagnetic surface, the present invention exhibits further effects.

(Effects of the invention) 1. .

As described above, the present invention provides a magnet in which a ferromagnetic surface can be easily obtained by a specific molding method, and a method for manufacturing the same, and as a result, magnetic properties superior to conventional methods can be effectively obtained. , its industrial value is extremely large.

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[Brief explanation of the drawing]

1 and 2 are schematic diagrams showing the pressing method according to the present invention, FIG. 6 is a perspective view of a magnet made according to the present invention (M indicates the anisotropic direction), and FIG. 4 is a schematic diagram showing the pressing method according to the present invention. A schematic diagram of a magnetic circuit consisting of the obtained magnet 41 and yoke 21, FIG. 5 is a sectional view of the right side, and FIG. 6 is a schematic diagram showing a conventional pressing method. 1...Dice 2.Upper bunch 3...
Lower bunch 4... Magnetic powder 5... Coil 6... Magnetic field (flow of magnetic flux) 21... Yoke 51... Lower punch non-magnetic part

Claims (1)

[Claims] 1. In filling a molding space formed by a die made of a non-magnetic material or a material with low magnetic permeability and an upper and lower punch made of a ferromagnetic material at least in part, and molding the powder, 1. A method for producing an anisotropic magnet, comprising press-molding by applying a magnetic field in a compression direction to a molding space so that the magnetic flux density on one punch surface is larger than that on the other punch surface. 2. The method for producing an anisotropic magnet according to claim 1, which comprises adding a binder to the magnetic powder. 3. The method for manufacturing an anisotropic magnet according to claim 1 or 2, wherein the anisotropic magnet is sintered after the press forming. 4. The method for manufacturing an anisotropic magnet according to claim 1, characterized in that a core pin made of a non-magnetic material or a material with low magnetic permeability is provided in the molding space. 5. R_1Co_5 alloy powder, R_2C as magnetic powder
o_1_7 alloy powder and RBFe alloy powder (however, R
A method for manufacturing an anisotropic magnet according to one of claims 1 to 4, characterized in that at least one of the following is used: 6. An anisotropic magnet produced by the manufacturing method according to claim 1.