JPS6237907A - Field permanent magnet - Google Patents

Abstract

PURPOSE:To obtain high demagnetization resistivity and high output by integrating a rare earth/boron/iron series permanent magnet including heavy rare earth elements and a rare earth/boron/iron series permanent magnet including light rare earth elements. CONSTITUTION:A field permanent magnet 1 is composed of a first region 2 having a high residual magnetic flux density and a second region 2 having a high coersive force and both regions 2, 3 are combined integrally. The region 2 is a sintered magnet having the composition consisting of R1 (where one or more among the elements eliminating Dy, Tb, Ho from the rare earth elements including Y) in the atomic ratio of 8-30%, B of 2-28% and remainder substantially consisting of Fe. The region 3 is a sintered magnet having the composition consisting of R2 (at least one memory Dy, Tb, Ho) in the atomic ratio of 8-30%, B of 2-28% and the remainder substantially consisting of Fe. Thereby, high demagnetization resistivity and high output may be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a field permanent magnet used in a permanent magnet rotating machine such as a permanent magnet generator or a permanent magnet motor.

(Prior Art) Conventionally, in rotating electric machines using permanent magnets, particularly small motors, generators, etc., ferrite magnets in the form of arc particles have been generally used as field permanent magnets. In particular, in motors that have a very large load during startup, such as starter motors for starting engine engines and motors for driving air conditioner compressors, the demagnetizing field due to armature reaction becomes large, so ferrite magnets with high demagnetization resistance are used. has been done.

However, in order to improve the output, it is necessary to have a high residual magnetic flux density, and moreover, as the output increases, the demagnetizing field due to armature reaction increases, so it is also necessary to have a high coercive force. However, it is difficult to satisfy these requirements with a ferrite magnet having a single composition, and there are certain limits in terms of output improvement and demagnetization time 14r.

Therefore, in order to overcome this limit, for example,
-3199 and 55-564! As described in each publication of No. i6, there is a part that is thicker than the other segment part and has a flux density of 2 residual 141, which has magnetic properties different from each other, and the other part [Dame 21 to part J, A composite type Lyle magnet, which consists of a magnet and a part with a large coercive force, has been proposed and put into practical use.

(Problems to be Solved by the Invention) The magnet for the above-mentioned composite type ferrite 1 has a coercive force (11"c
) shows a fairly high value such as 4,500 to 50'000 e, so although it is somewhat satisfactory in terms of demagnetization resistance, the residual magnetic flux density (Br ) is about 3,700 to 4,000 G [α, so it is not necessarily sufficient in terms of output. Well, it was /r.

In particular, this composite type ferrite magnet is manufactured by a special method such as an impregnation method (see, for example, West German Patent Publication No. 3,248,846), and is therefore more expensive than a ferrite magnet having the composition A. Therefore]] S1Hepuff A-
Mann's Sada C cannot necessarily be said to be advantageous.

The purpose of the present invention is (10) to solve the problems of the prior art.
Another object of the present invention is to provide a permanent magnet for field use that has high demagnetization resistance and high output, and has significantly improved magnetic field performance.

(Means for solving and overcoming the problems) The field permanent magnet of the present invention has R7 different magnetic properties and M
a first region having a higher residual magnetic flux density than the other, and a second region having a higher coercive force than the other, the first region having a second end region. A permanent magnet integrally coupled, the first region of which has a 1K ratio of 8
to 30% R+ (However, from rare earth elements including Y,
l) Within 1 second of the elements excluding V, Tti, llo -+1>, 2 to 28% B and the remainder is substantially l
-e, the second region has an atomic ratio of 8 to 30% of 1 and 2 (1'lr, db,
At least one of Ho and R1), 2 to 28% of 1
3 and the remainder are sintered magnets having a composition substantially ranging from e to i.

Currently known as permanent magnets are T-Li J-magnets, alnico magnets, Fe-Cr-co magnets, and rare earth magnets; however, alnico magnets and Fe-Cr-C
Since the coercive force of o11 stone is about 2000Qe or less, which is considerably lower than that of ferrite magnets, it cannot be put to practical use. On the other hand, rare earth magnets have a large residual magnetic flux density and a large coercive force, so they are sufficient in terms of performance. However, among rare earth magnets, rare earth cobalt magnets are expensive and cannot necessarily be said to be advantageous in terms of cost performance.

Therefore, the present inventor developed rare earth-boron-iron sintered magnets (Japanese Unexamined Patent Application Publication Nos. 59-46008 and 60-3230) that have similar magnetic properties, a large magnetic moment, and are advantageous in price.
6, No. 60-34005, etc.), and found that the above object could be achieved by using this as a permanent magnet for a field.

(Structure) As shown in FIG. 1, the field permanent magnet 1 of the present invention consists of a first region 2 having a high residual magnetic flux density and a second region 3 having a high coercive force. are integrally combined.

In order to obtain a sufficient residual magnetic flux density, the first region is a rare earth element (R1) and a rare earth element containing Y.
One or more of the elements excluding V, Tt+, and Ho are used. Among these rare earth elements, Nd is preferred from the viewpoint of magnetic properties and cost.

On the other hand, in the second region, in order to sufficiently increase the coercive force of 4T by 1q, DV belonging to heavy rare earths is used as a rare earth element (R2).
, Tb, 1-to at least one species 1-V and R1
It uses

The content of these rare earth elements R1 and R2 is preferably in the range of 8 to 30% in terms of atomic ratio (the same applies hereinafter). If it is less than 8%, the coercive force decreases. - Manpuku earth elements are easily flammable, difficult to handle, and expensive, so the content should be 30% or less.

The content of B is preferably in the range of 2 to 28%. If it is less than 2%, sufficient coercive force cannot be obtained, and if it exceeds 28%, the residual magnetic flux density will decrease.

The remainder is Fe containing unavoidable impurities, but a portion of e may be replaced with 40% or less of Go.Addition of CO improves the Kikoli point and improves the reversible tone coefficient.

For the same purpose as CO, a predetermined percentage or less of element A may be included. However, if two or more types are included,
The content of the hex element shall be less than or equal to the value of the hex element having the maximum value.

1-i 4.5% or less N18% or less 1315% or lessV 9,5 Nb 12,5 Ta
10,5Cr 8.5 Ma 9,5
W 9.5Mn 8 AcL9,
5 Sb 2,5Ge 7 Sn
3.5 Zr 5.511f 5.5
CLI 3,5 8 2C4Ca8
M(18 Si8 01 P3.5 The permanent magnet of the present invention can be manufactured by the following method.

Two types of inbots 1 to 1 are prepared by adjusting the specified composition, and each inbot 1 is coarsely pulverized using a show crusher or a brown mill, and then finely pulverized using a pulverizing means such as a ball mill or jet mill. Average particle size 1-20μm
obtain magnetic powder. When it is less than 1 μm or more than 20 μm, the coercive force decreases.

For example, a molding space divided into two areas by a vertically movable partition plate is filled with two types of magnetic powders of 1μ, and then compression molding is performed after removing one cut plate.The molding pressure is 1μ. -10t/cm2 is preferable, and j: more preferably ranges from 2 to 7110m2.

It goes without saying that by applying a magnetic field (above 5 KOeL'1.) during molding, the circumference is increased to 11 and the performance is improved.

The molded product obtained in this way is placed in a vacuum or
! Two types of 1i11? -i The sintered body in which the powders are integrally bonded is raised by one. Here, it is necessary to perform sintering in a non-oxidizing atmosphere to prevent oxidation of the rare earth element. If the sintering temperature is less than 900°C, the density will not be high and sufficient residual magnetic flux density will not be obtained, and if it exceeds 1200°C, the residual magnetic flux density and squareness will decrease. The above-mentioned sintered body is subjected to appropriate heat treatment (for example, aging treatment at a temperature of 500 to 800°C) to become a permanent magnet.

(Example) The details of the invention will be explained below with reference to Examples, but the invention is not limited thereto.

Example 1 A raw material 11 weighed to have a predetermined composition was melted and cast in Ar gas to obtain an atomic ratio of 15% Nd, 8% B, and the balance F.
An ingot with a composition (composition a) consisting of e and 13% Nd
An ingot having a composition (composed of III) consisting of -2% Dy-8% B-the remainder Fe was produced.

Both of the above two types of ingots were pulverized to an average particle size of 3.0 to 3.3 μm using a show crusher and a brown mill.

The two types of finely pulverized powder obtained were filled into the arc segment I-shaped molding space cut by a partition plate, and after removing the partition plate, it was compressed at a pressure of 5t/cm2 in a magnetic field of 10KOe. Molded.

This molded body was heated to U1100 in vacuum (10-4 torr).
Sintered under the conditions of 'Cx2h. 68 to the obtained sintered body
After being subjected to a heat treatment of 0'Cx211, it was rapidly cooled and processed to a predetermined size to obtain a permanent magnet (No. 1) shown in FIG.

The dimensions of this permanent magnet are γ1=35mm, γ2-26m
m, θ-53°, and the volume of the end portion 3 where the high r l-I 0 part is 1/4 of the whole. As a result of measuring the magnetic properties of the permanent magnet 1, in the central part 2 (composition a) (3r=11
．． 9KGXrl-1c = 9.5KOe T: Yes,
At end 3 (composition a) [3r = 11.2K G, r
HC=19.4KQe. The temperature at one point (Tc) in the center was 314°C.

Example 2 Instead of the ingot of composition a, 15%Nd-8%B-1
An ingot having a composition (a') consisting of 2% C0--balance Fe was produced, and a permanent magnet (NO2) was produced using this ingot under the same conditions as in Example 1 except for Jx.

As a result of measuring the magnetic properties of this permanent magnet, it was found that the end portion 3 (composition ()) was the same as in Example 1, and the center portion 2 (composition a'
) then B r = 11.8K G , r HC =
9.21 (Qe). Also, the Curie temperature (Tc) of the central part 2 was 419°C, and part of the Fe was CO
It can be seen that the temperature was improved by 105°C compared to Example 1 by substituting with.

Example 3 Ingots with various compositions shown in Table 1 were prepared and used to create a permanent magnet in which the center part 2 was made of composition 1 and the end parts 3 were made of composition 2 under the same conditions as in Example 1. (No.3~N
01) was produced. Table 2 shows the magnetic properties and Curie temperature (Tc) of these permanent magnets.

(Hereinafter in the margin) (Hereinafter in the margin) When the permanent magnets of each of the above examples were incorporated into an automobile starter motor and tested under normal usage conditions, it was found that the composite 3r ferrite magnet (height 13r part Br = 4.0
It was confirmed that the motor output was improved by 1.5 to 3 times compared to the KG1 high IHc section (11-10 = 5.0 KOe).

(Effects of the Invention) As described above, the field permanent magnet of the present invention includes a rare earth/boron/iron based permanent magnet containing a heavy rare earth element, and a rare earth/boron/iron based permanent magnet containing a light rare earth element. Since it is a composite permanent magnet with an integrated magnet, it is possible to obtain significantly higher output than conventional ones when used in a starter motor.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an arc segment 1-type permanent magnet.

Claims (2)

[Claims] (1) Consisting of a first region having different magnetic properties and having a higher residual magnetic flux density than the other, and a second region having a higher coercive force than the other, the first region and the first region have different magnetic properties. In the field permanent magnet in which the second region is integrally combined, the first region has an atomic ratio of 8 to 30%.
R_1 (However, from rare earth elements including Y, Dy, Tb,
A sintered magnet having a composition consisting of at least one element (excluding Ho), 2 to 28% B, and the remainder substantially Fe, and the second region has an atomic ratio of 8 to 30% B. R_2(
At least one of Dy, Tb, and Ho and R_1), 2
A permanent magnet for a field, characterized in that it is a sintered magnet having a composition of ~28% B and the remainder substantially Fe. (2) The permanent magnet for a field according to claim 1, wherein at least one of the sintered magnets is a magnet in which a portion of Fe is replaced with Cu of 40% or less in atomic ratio.