JPS63152110A - Manufacture of permanent magnet - Google Patents

Abstract

PURPOSE:To manufacture the anisotropic permanent magnet having a high energy product by a method wherein the thin strip or powder.piece-like material consisting of rareearth-iron alloy, having the magnetic coercive force at the normal temperature brought down to the prescribed value or below, is plastically deformed by performing a super-quenching operation, and a magnetic anisotropic property is given to said material. CONSTITUTION:The thin strip or powder.piece-like material consisting of rareearth-iron alloy having the magnetic coercive force at the normal temperature of 3 koe or below, for example, is plastically deformed at the temperature of 600 deg.C or above, for example, by performing a superquenching treatment, and a magnetic anisotropic property is given to said material. At this point, when a thin strip is going to be manufactured using a method wherein the melted metal of a rareearth-iron alloy is superquenched, there are methos such as a centrifugal quick-cooling method in which material is solidified by quenching by jetting out a fused alloy from a nozzle against the inner wall of the cooling drum which is rotated at high speed, and also a single-rolling method and the like wherein material is quickly cooled and solidified by jetting out a fused alloy against the outer wall of a rotating drum in the same manner as the method mentioned above. Amorphous quenching of 50 vol. % or more is added to the thin strip or powder.piece-like material after the material has been quickly cooled. As a result, the anisotropic permanent magnet having a high energy product can be obtained without lowering saturated magnetization and magnetic coercive force even when said material is heated up to 600 deg.C or above at which it can be plastically deformed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a method for manufacturing a water-filled magnet that is used for manufacturing an anisotropic water-filled magnet.

(Prior Art) In recent years, rare earth-iron permanent magnets have been attracting attention as magnets that have even better magnetic properties than conventional alnico magnets and rare earth-cobalt magnets.

(Problems to be Solved by the Invention) In order to provide magnetic anisotropy through plastic deformation in such a rare earth-iron permanent magnet, a thin strip made of a rare earth-iron alloy that exhibits high coercive force after quenching is used. And/or when powder/flake bodies or intermediate molded bodies thereof are heated to a temperature of 600'c or higher at which plastic deformation is possible, saturation magnetization (4πIs) and coercive force (BHa, IHa
) will decrease significantly, resulting in a high energy product (
(BH) max) cannot be manufactured.

(Objective of the Invention) This invention was made by focusing on the above-mentioned problems of the conventional art.
It is an object of the present invention to provide a method for manufacturing a permanent magnet that is capable of manufacturing an anisotropic permanent magnet of BH) max).

[Structure of the Invention] (Means for Solving the Problems) The method for producing a permanent magnet according to the present invention is to produce a thin ribbon and/or powder made of a rare earth-iron alloy whose coercive force at room temperature is reduced to 3 KOe or less by ultra-quenching.・Heat the flakes at 600℃
It is characterized in that it is plastically deformed at a temperature above or above to impart magnetic anisotropy.

The rare earth-iron alloy to which this invention is applied is R1
, -β, -δ(F e (N r , M n .

co)) (xxβMyA6, where R is one or more rare earth elements, and X is B, C, or N.

One or more of St, P, M is T i ', Z r
.

Hf, V, Nb, Ta, Cr, Mo, W, AM.

One or more of Zn, Ga, In, TJI, A is Ru
, Rh, Pd, Os, Ir, and Pt.

Among the above, Fe (Ni, Mn, Co) is an element group effective for improving the residual magnetic flux density (Br), and is a part of Fe, preferably 0.10 in atomic ratio.
It is possible to replace Fe1N i , Mn , and Co below, and by adding appropriate amounts of Ni and Mn, the coercive force (B
It is possible to raise the Curie point by adding an appropriate amount of CO, and to obtain a good maximum energy product ((BH)max), 0.6
It is more desirable that 0≦α≦0.85.

In addition, the X element is an element that contributes to improving magnetic properties, and 1
When the M element is added, it is possible to improve the magnetic properties by combining with some of these elements to form borides, carbides, nitrides, silicides, phosphides, etc. It is particularly desirable that 0.15.0≦γ≦0.01.

In general, since the platinum group element group, which is element A, contributes to improving corrosion resistance, it may be added as necessary in the range of 0≦δ≦0.02.

In this invention, the molten metal of the rare earth-iron alloy exemplified above is supercooled by ultra-quenching, and the coercive force of the resulting ribbon-shaped ribbon, powder, or flake at room temperature is 3 KOe or less. Make it so. That is, the ribbon-like thinning 1? If the coercive force of powder or flakes at room temperature is 3 KOe or less, saturation magnetization (4πIs) and Coercive force (BHC.

This is because it is possible to obtain an anisotropic permanent magnet having a high energy product without reducing rHc).

Therefore, in order to ultra-quench the molten metal of rare earth-iron alloy so that the coercive force of the ribbon-shaped ribbon, powder, or flakes at room temperature is 3 KOe or less, it is necessary to Amorphous (
It is particularly desirable that the amount of amorphous is 50% by volume or more.

In this case, the ultra-quenching method for the rare earth-iron based molten alloy includes a centrifugal quenching method in which the molten alloy is injected from a nozzle onto the inner wall of a cooling drum that rotates at high speed to rapidly solidify it when manufacturing a ribbon; There is a single-roll method in which molten alloy is similarly injected onto the outer wall of a rotating drum and then rapidly solidified, and a twin-roll method in which molten alloy is injected onto the contact surfaces of two drums that rotate at high speed and are rapidly cooled and solidified. When producing a powder, the spark diroggon method or atomization method is used, and when producing a flake, the above-mentioned ribbon-like thin strip is crushed. Adopt methods etc.

When a ribbon-like thin strip is produced by a roll method, ultra-quenching is performed at a roll circumferential speed of 15 m/sec or more, and the amorphous material in the resulting ribbon-like thin strip or powder φ flakes is By ensuring the amount is more preferably 50% by volume or more, the coercive force (BHC) at room temperature can be improved.
, z Ha) is 3 KOe or less, and even when heated to a temperature of 600° C. or higher that allows plastic deformation later, the saturation magnetization (4πIs) and coercive force (BHC) are maintained.

rHc) so as not to decrease.

Next, if necessary, the ribbon-like thin strip and/or powder plate-like body is formed into an intermediate molded body by, for example, cold pressing or hot pressing, and then the intermediate molded body is made into a material that can be conveniently deformed. It is heated to a temperature of 600℃ or higher and subjected to plastic processing such as upsetting and rolling.
An anisotropic permanent magnet is obtained by forming an axis of easy magnetization in a direction perpendicular to the stretching direction of the material.

(Example 1) 29 wt% Nd-64 wt% Fe-5 using an induction furnace
After melting a rare earth-iron alloy having a composition of 0.8 wt.% Co, 0.8 wt.% B, 1.2 wt.% Cr, the molten alloy was rolled at various roll peripheral speeds (see Figure 1). A ribbon-like thin strip was produced by spraying onto a rotating roll. Then, the amorphous amount (measured by X-ray diffraction) in the ribbon-like ribbon obtained for each of the different roll peripheral speeds (Vs) and the maximum energy product ((BH) max),
When the relationship between residual magnetic flux density (Br) and coercive force (rHc) was investigated, the results are shown in FIG.

As shown in FIG. 1, in this embodiment 1, the roll circumferential speed (
If a ribbon-like thin strip is produced with Vs) of about 21 m/sec or more, the amount of amorphous in this ribbon-like thin strip will be about 4 m/sec or more.
The coercive force (rHc) of the ribbon-like 7-magnetic band at room temperature could be reduced to about 3 KOe or less.

Next, the ribbon-like thin strips having different amounts of amorphous were compression molded separately using a molding pressure cuff tonf/Cm2, and hot isostatic pressing (HIP treatment) was performed at a pressure of 1500 kgf/cm2 at 750°C. An intermediate molded body was obtained.

Next, each of the intermediate compacts after the HIP treatment was subjected to upset processing at a temperature of 700° C. and a processing rate of 50% to cause plastic deformation, thereby aligning the axis of easy magnetization in the upsetting direction. Roll circumferential speed (
The relationship between the maximum energy product ((BH) max), the residual magnetic flux density (Br), and the coercive force (IHc) was investigated, and the results are shown in FIG. 2.

As shown in Figure 2, the circumferential speed of the roll during ultra-quenching is approximately 21 m.
If an anisotropic magnet is manufactured by forming an intermediate compact using a ribbon-like thin strip made of a rare earth-iron alloy with a temperature of /Sec or more and then plastic working the intermediate compact, the coercive force ( It was confirmed that an anisotropic permanent magnet with a large maximum energy product ((BH)max) and a large residual magnetic flux density (B r ) and a large residual magnetic flux density (B r ) could be manufactured.

(Example 2) 28 wt% Nd-66 wt% Fe-4 using an induction furnace
wt% Co-0,5 wt% B-0,5 wt% AJZ-1
After melting a rare earth-iron alloy having a composition of .
A ribbon-like thin strip was produced by spraying the mixture onto a rotating roll (see FIG. 3). Then, the amorphous amount (measured by X-ray diffraction) in the ribbon-like ribbon obtained for each of the different roll circumferential speeds (Vs) and the maximum energy product (
(BH)max), residual magnetic flux density (Br), and coercive force (XHc), the results are shown in FIG.

As shown in FIG. 3, in this embodiment 2, the roll circumferential speed (
If a ribbon-like thin strip is produced with Vs) of about 25 m/sec or more, the amount of amorphous in this ribbon-like thin strip will be about 8
The coercive force (rHc) of the ribbon-like ribbon at room temperature could be reduced to about 3 KOe or less.

Next, the ribbon-like thin strips having different amounts of amorphous were compression-molded separately at a molding pressure cuff tonf/am2, and at 750°C and 1500 kgf/cm2 (7
) hot isostatic pressing (HIP treatment) was performed at a pressure to obtain an intermediate molded body.

Next, each of the intermediate compacts after the HIP treatment was subjected to upset processing at a temperature of 700° C. and a processing rate of 50% to cause plastic deformation, thereby aligning the axis of easy magnetization in the upsetting direction. The roll circumferential speed (
When the relationship between the maximum energy IA ((BH) max), the residual magnetic flux density (Br), and the coercive force (rHc) was investigated, the results are shown in FIG. 4.

As shown in Figure 4, the circumferential speed of the roll during ultra-quenching is approximately 25 m.
If an anisotropic magnet is manufactured by forming an intermediate compact using a ribbon-like thin strip made of a rare earth-iron alloy with a hardness of at least /see and then plastically working the intermediate compact, the coercive force ( It was confirmed that it was possible to manufacture an anisotropic permanent magnet with a large maximum energy product ((BH)max) and a large residual magnetic flux density (B r).

[Effects of the Invention] As explained above, according to the method for manufacturing a permanent magnet according to the present invention, a ribbon and/or powder φ made of a rare earth-iron alloy whose coercive force at room temperature is reduced to 3 KOe or less by ultra-quenching. Since the flakes are deformed in a rectangular manner at a temperature of 600'O or higher to impart magnetic anisotropy, thin bodies made of rare earth-iron alloys and/or powder/flake bodies or intermediates thereof can be produced. It is possible to prevent the saturation magnetization (4πI s) and coercive force (BHC, rHc) from decreasing even when the molded body is heated to a temperature of 600'C or higher, at which it is possible to form the molded body. , a rare earth-iron based anisotropic permanent magnet with a high energy product! The very excellent effect that it is possible to create iJ is brought about.

[Brief explanation of the drawing]

FIG. 1 shows 29% by weight Nd-
64% by weight Fe-5% by weight Co-0,8% B-1,
Roll circumferential speed (Vs), amorphous boron in the ribbon, and maximum energy product ((BH) when a ribbon-like thin strip is produced by a roll method from a molten earth-iron alloy having a composition of 2% by weight Cr. max), residual magnetic flux density (Br)
FIG. 2 is a graph showing the results of investigating the relationship between the magnetic field and the coercive force (IHC), and FIG. Roll circumferential speed (V
s), maximum energy product ((BH) may), residual magnetic flux density (Br), and coercive force (Hc). %Nd-66wt%Fe-4wt%Co-0
, 5 wt% B-0.5 wt% A or -1.0 wt% Ru when a ribbon-shaped thin strip is produced by a roll method from a rare earth-iron alloy molten metal having a composition of: 5 wt% B-0.5 wt% A or -1.0 wt% Ru
Graph showing the results of investigating the relationship between the amount of amorphous in the VI band, the maximum energy product ((BH) max), the residual magnetic flux density (Br), and the coercive force (IHC), 4th
The figure also shows the roll peripheral speed (Vs) and the maximum energy product (( BH)max), residual magnetic flux density (B
FIG. Fig. 1 Ryo7 Rufus amount (1%) Fig. 2 O-ru Peng JL Vs (m/s) Fig. 3 A7 Rufus 7st (1%) Fig. 4

Claims (4)

[Claims] (1) Magnetic anisotropy is imparted by plastically deforming ribbons and/or powders/flakes made of rare earth-iron alloys whose coercive force at room temperature has been reduced to 3 KOe or less by ultra-quenching at temperatures of 600°C or higher. A method for manufacturing an anisotropic permanent magnet, characterized by: (2) Rare earth-iron alloy is R_1_-_α_-_β_
−＿γ＿−＿δ{Fe(Ni, Mn, Co)}_αX_
It is expressed as βM_γA_δ, and R is one of the rare earth elements.
species or more, X is one or more of B, C, N, Si, P,
M is Ti, Zr, Hf, V, Nb, Ta, Cr, Mo,
One or more of W, Al, Zn, Ga, In, Tl,
A is one or more of Ru, Rh, Pd, Os, Ir, and Pt, and 0.60≦α≦0.85, 0<β≦0.
15, 0≦γ≦0.01, 0≦δ≦0.02, The method for manufacturing an anisotropic permanent magnet according to claim (1). (3) The ultra-quenched rare earth-iron alloy ribbon and/or powder/flake has an amorphous content of 50% by volume or more. The method for manufacturing an anisotropic permanent magnet according to item (2). (4) The thin strip and/or powder/flake made of ultra-quenched rare earth-iron alloy is manufactured through a process in which molten alloy is injected onto a roll rotating at a peripheral speed of 15 m/sec or more. A method for manufacturing an anisotropic permanent magnet according to any one of claims (1) to (3).