JPS5985844A - Rapidly cooled magnet alloy - Google Patents

Abstract

PURPOSE:To improve the machinability and magnetic characteristics by spraying a molten alloy consisting of Nd, Pr and Sm as rare earth elements, Fe and Co represented by a prescribed compositional formula on the surface of a prescribed rotating body. CONSTITUTION:An alloy represented by a compositional formula Re1-x(Fe1-y Coy)x (where x is 0.4-0.7, y is 0.01-0.4, and Re is two or more among Nd, Pr and Sm as rare earth elements) is refined. The molten alloy is sprayed on a rotating body rotating at 5-30m/sec surface speed, and it is rapidly cooled. The resulting magnet alloy has superior machinability and magnetic characteristics.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to rapidly solidified magnetic alloys, and more particularly to Nd,
Two or more of the rare earth elements Pr, Sm and Fe
The present invention relates to a rapidly solidified magnetic alloy obtained from an alloy consisting of , Co, and Co.

Conventionally, as a rare earth magnet alloy containing rare earth elements, SMC
Intermetallic compound magnets represented by o5, smco7, Sm2co17, etc. are known. These rare earth magnets have excellent magnetic properties and are currently widely used.

In general, the manufacturing method of rare earth magnets requires melting, crushing, press forming, and sintering temporary heat treatment in order to obtain excellent magnetic properties, and moisture management is extremely complicated. Since it is Ei, it has drawbacks such as being brittle and having extremely poor machinability.

The present invention was made to improve this point, and the gist thereof is the compositional formula Re I-X (Fe +-yco v )
X [However, 0.4≦X and 0.7.0.01≦Y≦0.
Re is the rare earth element Nd, pr, 3m
5 to 30 m/m of molten alloy consisting of two or more of -F
This is a rapidly solidified magnetic alloy characterized by being rapidly cooled from a molten metal by injecting it onto the surface of a rotating body having a surface speed of sec.

The rapidly solidified magnet alloy of the present invention is completely different from conventional crystalline rare earth magnet alloys in terms of composition and phase. Judging from the results of X-ray diffraction, the structure of the rapidly solidified alloy obtained from the range of the compositional formula of the present invention is such that the surface speed of the rotating body during rapid cooling is 30 m/sec.
If it is close to c, it is an amorphous structure based on X-rays. Also,
When the velocity is close to 5 m/sec, the diffraction pattern is similar when compared with an arc-melted ingot of the same composition, but the diffraction peak height is significantly smaller than that of the ingot, making it superior. It is thought that it exhibits magnetic properties.

The substances present in the rapidly solidified magnet alloy in this case include the rare earth metals Re (Nd, Pr, Sm), Re(Fe
, Co)? and Re2 (Fe, Go)17 or a mixture of metal-to-intermetallic compounds. Therefore, in the present invention, in order to obtain excellent magnetic properties, the surface velocity should be 5 to 30 m/, se
c and rare earth metals Re (Nd,
Pr, 8m), intermetallic compound Re (Fe,
The condition is that the amounts of Co ) 2 and Re2(Fe, Co)+7 are smaller than the amounts of polycrystalline alloys having the same composition. This is clear from the following test. That is, an alloy obtained from the above composition formula was produced by high frequency melting or arc melting. The alloy ε is a polycrystalline alloy, and when the substance was identified by powder X-ray diffraction, the presence of the following substance was confirmed based on the type and content of rare earth elements (Nd, Pr 1Sm ). (1) When Re is Nrl-Pr, Re metal, Rez (re 1Co ) + 7, (21 when Re is Nd -8m, Re metal, Re (Fe,
CO)2Re2(Fe,Co)+7,[
When Re is Pr-8m as 31, Re metal, R
e (Fe, Co)2, Rez (Fe, Co)+7,
When Re is Nd-Pr-3m, Re metal Re (Fe, Co)2, Re2 (Fe, Co)
It was identified as an alloy consisting of a single element shown by No. 17 and a pentacompound of an intermetallic compound.

When the magnetic properties of these alloys were measured using a sample vibrating magnetometer at room temperature, the coercive force (+Hc) was ~400 (Oe).
Magnetization (σIO) when applied magnetism tllOK (Oe)
K) is ~42 (emu/!) degree 1
This blocky polycrystalline alloy has a +
The improvement in c and σ values is extremely small, and there is little hope of using it as a rare earth magnet due to its magnetic properties or cost. In the present invention, it can be made to have excellent magnetic properties by rapid cooling treatment.

Next, the reasons for limiting the scope of the claims of the present invention will be described.

First, the composition formula Re +-x (Fe I-YCOY)
If X is 0.4, the 17 value will be 1000 (Oe) or less.

Also, if x > 0.7! Since the W value is extremely reduced and the amount of rare earth elements is extremely large, it is disadvantageous as an industrial product due to high cost. Further, in the case of transition metal (Fe+-vcOv) and Y<0.01, the magnetization σ value decreases, and there is also a drawback that it is difficult to obtain a ribbon-shaped ribbon of good quality by rapid cooling. Further, when y>0.4, the magnetic flux and σ value decrease, and a rapidly solidified magnetic alloy having excellent magnetic properties cannot be produced.

The quenched magnetic alloy of the present invention is produced by a liquid quenching method in which a molten metal is injected onto the surface of a metal rotating body, which is generally used in the production of amorphous magnetic materials, to obtain a ribbon-shaped sample r1. In the liquid quenching method, the constituent elements F8+ or alloys are charged into a crucible made of quartz, oxide, or high melting point metal, melted by high frequency or resistance heating, and then passed through a molten metal outlet set at the bottom of the crucible. Ar gas injection pressure from 0.1 to
A ribbon-shaped magnetic alloy is obtained by injection and quenching onto the surface of a metal rotating body at 1 kg/cm2.

These melting and injection operations must all be carried out in an inert gas atmosphere such as Ar or nitrogen gas in order to prevent oxidation of the rare earth elements. The material of the rotating body for rapidly cooling molten metal can be OLI, Fe and its Cr plating, heat-resistant and contact-resistant alloys such as stainless steel, or ceramics. It is preferable to use a surface treatment of different metals or ceramics. The shape of the rotating body is a roll, a disk, etc., and the molten metal may be injected into the inner surface of a cylinder.

The magnetic properties of the rapidly cooled 11 magnet alloy of the present invention, the obtained magnet alloy, vary significantly depending on the cooling rate on the surface of a high-speed rotating body, such as a rotating roll. In order to obtain a magnet alloy with excellent magnetic properties, the surface speed of the rotating body should be 5 to 30 m /
sec. For example, in the case of a rotating roll, the surface speed of the rotating body is the circumference of the roll x the number of rotations (r).

p, m>. The ribbon thickness of the ribbon-shaped magnet alloy obtained when the surface speed of the rotating roll is 5 to 30 m/sec is about 10 to several hundred μm, but when the surface speed of the rotating body exceeds 30 m/sec, the ribbon thickness becomes extremely thin. As the thickness becomes thinner, it becomes difficult to obtain a continuous long ribbon of good quality. Since the rapidly solidified magnetic alloy obtained from these manufacturing methods is a thin ribbon, it requires a significantly larger number of manufacturing steps than the method of cutting sintered magnets for use with thin plate-shaped hard magnetic materials. In addition to the simplification, it is also advantageous in terms of cost because it can be manufactured by only machining and cutting. Furthermore, since the magnetic properties can be improved without necessarily requiring heat treatment at high temperatures, this is also an advantage.

The details of the present invention will be explained below using Examples.

Example 1 1iil of the raw materials used! Maro is a rare earth metal, and both e and CO are 99.8% or more. To prepare a rapidly cooled sample, first, an alloy ingot with a predetermined composition is created by arc melting, and then the roll surface speed is set to 1 by the above-mentioned rotating roll method.
The test was carried out at a speed of 1.8 m/sec. Table 1 shows the magnetic properties when changing the composition ratio of rare earth elements Nd and pr.
and σIOK + direct are shown for the three scales. The magnetic properties of the alloy ingots of samples 1 to 3 are as follows: ~400
(Oe), σ = 42 (emu/(1)).

0Q o Q O Seven. 0 0 0 0 0 Q　　　　　　　　.

state 0
B 6 o OO o o 6 tg Mo 6 z r-C%J of 101 Example 2 Table 2 shows Ra I-X (F[! +-vco v )
x [(jl, L O, 4≦×≦0.7.0.01 @
Y≦0.4] In the 1'L 1 formula shown in F, Y=0.
The composition and magnetic properties of rapidly cooled samples obtained by changing the X value in case 2 are shown. D-ru surface speed is 11.8 m/
It was done in sec.

From Table 2, the relationship between rare earth element combinations and magnetic properties is that Nd is rich as a rare earth element, and rare earth elements and (FeO, 8C
The magnetic properties were good when the X value, which is the ratio of o 0.2 ), was X-0.6. By the way, (N(I n, e P
o,2 ) 0.4 (Fe o,s Co O,2>
. Test F11, indicated by 6, is! To 7200 (00),
σ1OK-56 ((!111+17g) There was.

The magnetic properties of alloy inbot 1- of test N4-12 are &-~
400 (Oe), (710 = 40 (emu /
Q) and -).

10- > 兇 ふん み k ( ふ ん り み き Ｇｕｎ Ｇｕｎｄ 訳 3) Table 3 shows Re +-x (Fe 1-YcOy ) X
[However, 0.4≦')<≦0.7.0.01≦Y≦0.4
] The compositional formula and magnetic properties of the rapidly solidified alloy obtained when the Y value is changed when X=0.6 in the shown compositional formula are not shown. Roll surface speed is 11.8 m/s
It was carried out using ec.

From Table 3, the relationship between the composition ratio of FC and CO and magnetic properties is Y=
It was found that the composition shown in Sample 1, which was close to 0.2, was excellent in terms of magnetic properties.

2 × Ten 131 Example 4 Table 4 shows (Ndo, e Pr O,2) o, 4(Fe
The relationship between the surface speed and magnetic properties of a rapidly cooled sample obtained when the surface speed of a rotating roll of an alloy represented by o,8GO0,2)0.6 is changed is shown.

Table 4 Sample Roll Surface Speed Magnetic Characteristics NO, (Il
l/sec) & σ(Oe)
(emu / (1) 15 3.9 600 4616
7.8 5800 521
11.8 7200 56 From Table 4, it was found that the magnetic properties of the rapidly cooled samples were largely dependent on the surface speed of the rotating roll. This is (Nd O, B pr 0
．． 2) 0.4 (Fe O, [l C0°, 2)
. The magnetic properties of the alloy ingot of No. 6 are +tk:= 35
0 (Oe), σ1OK=41 (emu 7g)
Therefore, the roll surface 1 during rapid cooling from molten metal
It has been found that samples with excellent magnetic properties can be obtained by controlling 4-. In addition, the surface speed is 5 to 30
A range of m/sec is necessary from the viewpoint of magnetic properties.

As described above, according to the present invention, the material of the polycrystalline material is ~
This is the maximum 7200 (Oe) compared to the alloy which is 400 (Oe).
It is possible to produce quenched magnetic alloys with values of Oe).

Patent applicant Mitsubishi Steel Corporation Agent: Patent attorney: Hidetake Komatsu 15- 213-

Claims (1)

[Claims] (1) Composition formula Re +-x, (Fe +-vc
o v ) X [However, 0.4≦X≦0.7.0.0
1≦Y≦0.4], Re is the rare earth element Nd
, pr, 3m, is injected onto the surface of a rotating body having a surface velocity of 5 to 30 m/sec, and the molten metal is rapidly cooled. alloy.