JPS60138056A - Material for sintered magnet - Google Patents

Abstract

PURPOSE:To improve the press formability of a material for a sintered magnet without deteriorating the magnet characteristics by adding a small amount of Li, Zn, In, Ag, Sn, Pb or the like to the material contg. a rare earth element, B and Fe blended as essential components in a specified ratio. CONSTITUTION:This material for a sintered magnet consists of, by atom, 8-30% one or more kinds of rare earth elements including Y, 2-28% B, 65-82% Fe and a prescribed amount or less of one or more kinds of added elements selected from a group A consisting of <=0.5% Li, <=2.0% Zn, <=1.0% In, <=2.0% Ag, <=2.0% Sn and <=2.0% Pb and a group M consisting of Al, Ti, V, Cr, Mn, Zr, Hf, Nb, Ta, Mo, Ge, Sb, Sn, Bi, Ni and W. The material may further contain <25% Co. By the composition, a sintered permanent magnet having high performance can be formed without using much Co.

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a rare earth/iron permanent magnet that does not use cobalt CO, which is an expensive and scarce resource, and particularly relates to a sintered magnet that improves press formability. .

[Background technology]

Permanent magnetic materials are important electrical and electronic materials that are used in a wide range of fields, from various household electrical appliances to large computer terminal equipment. As a result, permanent magnet materials are becoming increasingly smaller and more sophisticated.

Rare-earth cobalt magnets are currently used as high-performance magnets, but these rare-earth cobalt magnets require Sm, which is a rare resource, and use a large amount of CO, which is in unstable supply, so they are expensive. be.

Therefore, the present inventors conducted intensive research to obtain a new permanent magnet that does not necessarily require the use of rare earth elements such as Sm, and does not contain large amounts of resource-unstable components such as 00. We have discovered a high-performance sintered magnet of the FeBR system (iron-boron-rare earth element system) whose main components are (Japanese Patent Application No. 176248/1984, etc.).

Since it is a FeBR-based sintered unsintered permanent magnet, it is often used in small electrical equipment, and the unit weight when press-molded is 0.5~
Since it is extremely small at 5.0 g, the accompanying improvements in press cycle and die life greatly contribute to improving production efficiency and reducing manufacturing costs of water-based magnets.

FeBR-based sintered magnets are manufactured by powder metallurgy methods,
The molding can be done by either dry press or wet press, but according to wet press.

Since the variation in unit weight is larger than that in dry pressing, there are drawbacks such as a decrease in raw material cost yield and an increase in complexity in the processing process of the final manufacturing process.

[Problem of the present invention]

On the other hand, in dry presses, the raw material powder tends to accumulate between the dies and punches, which shortens the life of the expensive dies and punches. This is done to improve the mold release properties of the powder, but this increases the process of applying the mold release agent, which significantly reduces the press cycle for products with small unit weight and many presses. The problem was that it was difficult to store.

〔the purpose〕

An object of the present invention is to further improve the press formability of FeBR-based sintered magnets without impairing their high-performance magnetic properties.

[Summary of configuration of the invention]

As a result of intensive studies to improve these press formability, the present inventors added the additive element A to the alloy system mainly composed of FeBR system.
It has been found that press formability is improved by adding one or more of Pb and Pb in a predetermined amount or less.

That is, according to the FeBR-based sintered magnet of the present invention, the apparent density of the starting raw material powder during production can be improved and the number of punches removed can be reduced. The moldability can be considerably improved.

Of course, the good magnetic properties of FeBR magnets are
As shown by the data described below, this is sufficient.

For this reason, the FeBR-based sintered magnet of the present invention contains 8 to 30% of the rare earth element R and 2 to 28% of the B by atomic percentage.
Similarly, the main component is 65 to 82% Fe, and a predetermined amount of one or more additive elements A is added. Among these, the rare earth element R is composed of one or more rare earth elements including Y, and the additive element A is M 0
Li 0.5% or less, Zn 2.0% or less, In 1 for each element in atomic percentage except %
．． 0% or less, Ag 2.0% or less, Sn 2.0% or less, Pb 2.0% or less.

In addition, when the additive element A is of two or more types, the content of the additive element A is set to be less than or equal to the maximum value of the respective additive elements of the contained A.

[Preferred aspect]

The present invention will be explained in further detail below.

The content of the rare earth element R is set at 8% or more in order to achieve a coercive force of 1 koe or more, and it is also 30% because it is expensive because it is easily flammable due to its nature and is difficult to handle and manufacture industrially.
The following shall apply.

The B content is 2% or more to obtain a coercive force of 1 kOe or more, and the residual magnetic flux density (Br) of hard ferrite is 4 kG.
In order to achieve the above, it is set to 28% or less.

The content of Fe is 65 to 82%. Fe content is 8
If it exceeds 2%, the coercive force becomes less than 1 koe, while 65
%, the residual magnetic flux density (Br) will be less than 4 kG.

The maximum energy product (BH) of such a sintered magnet of the present invention
max is equal to or higher than that of a hard ferrite magnet (~4MGOe).

Additive element A has the effect of improving the apparent density of the powder during press molding, improving the press cycle, improving the life of the die, and further reducing the so-called extraction pressure during punch extrusion, contributing to the improvement of the life of the die.

The additive element A is the predetermined amount of Li0.5%, Zn2%, In
1.0%, Ag2.0%, Sn2.0%, Pb2.0%
If it exceeds this, the alloy becomes sluggish, so if the ingot method is used, the grinding time of the alloy becomes longer, and the magnetic properties of the magnet gradually decrease as the content of additive element A increases. Therefore, the industrial merit will be reduced.

A preferable effective amount of addition is about 0.05% or more in total for A, and about 0.05% or more for each additive element, but more preferably 0.1% in total for A, and for each additive element when added alone. Each contains 0.1% or more.

In addition, additive element A has the effect of improving the tap density of powder during press forming, which improves the cycle of powder supply to the die and improves the filling of the powder into the supply hopper, both of which improve the tap density of powder during press forming. It significantly contributes to improving efficiency and productivity.

A more preferable composition range for FeBH includes light rare earth elements such as neodymium Nd and praseodymium Pr in an amount of 50% or more of the total R, and 11 to 2-4% of R13.
The main components are ~27% B and 68-80% Fe,
Additional elements A include Li 0.3% or less, Zn 1.5% or less, In 0.8% or less, Ag 1.5% or less, Sn
1.5% or less, Pb 1.5% or less (however, when two or more types of additive elements A are included, the content of A is not more than the atomic percentage of the one having the maximum value among the respective elements of A contained ).

The maximum energy product (BH) max in this case is 7 M G
It becomes more than Oe.

Furthermore, the most desirable composition range for FeBR, which has excellent magnetic properties and good press formability and industrial productivity, contains light rare earth elements in an amount of 50% or more of the total R, and 1
2-20% R14-24% B, 70-78% Fe
is the main component, and the additive elements A are Li 0.2% or less, Zn 1.0% or less, In 0
．． 5% or less, Ag 1.0% or less, Sn 1.0% or less, Pb 1.0% or less, and when two or more types of additive elements A are included, the content of A is the content of each element of A contained. It shall be less than the atomic percentage of the one with the maximum value. The maximum energy product (BH) max in this case is more than 1OMGOe, and the highest energy product reaches 33MGOe or more.

[Manufacturing example]

Next, an example of manufacturing the sintered magnet of the present invention will be explained in the case of a magnetically anisotropic magnet, but a magnetically isotropic magnet can also be manufactured in the same manner by performing press forming without applying a magnetic field. method can be adopted.

Fe as a starting material is electrolytic iron with a purity of 99.9 wt% or more, B is ferroboron or poron with a purity of 99 wt% or more,
R has a purity of 99.7wt% or more, and the additive element A has a purity of 98w.
t% or more is used.

The alloy is obtained by arc melting or radio frequency melting and casting into water-cooled copper molds. Grinding is done by stamp mill at 35 mesh (
500 ILm) is coarsely pulverized to a through-hole, and then finely pulverized to 0.5-10 pm using a ball mill.Press molding is performed by applying a magnetic field of 8 kOe or more to 0.5-2.5 ton/min.
cm". Sintering is performed at a temperature of 1000 to 1200°C for 0.5 to 4 hours in an Ar atmosphere. Further, aging treatment is performed in an Ar atmosphere at a temperature range from 350°C to the sintering temperature of 0.5 to 4 hours. A water-based alloy magnet can be obtained by carrying out the process for 5 to 8 hours.

Hereinafter, in order to clarify the effects of the present invention, several examples will be given and compared with comparative examples of peripheral compositions.

Example 1 An alloy having the following atomic percentage was weighed, high-frequency melted in argon, and cast.
After coarsely pulverizing the powder to a particle size of 2 to 5 pm, an alloy powder was obtained. The apparent density, tap density, and extraction pressure of the obtained alloy powder were measured using an Amsler press machine. ot/ct
After pressure molding with n' to obtain a molded product, 99.99wt
% purity Ar at 1100° C. for 2 hours and cooled to room temperature. Further, aging treatment was performed at 550° C. for 4 hours to obtain a water-based alloy magnet. The results are shown in Table 1.

Example 2 An alloy having the following atomic percentage was weighed, high-frequency melted in argon, and cast.
After coarsely pulverizing the powder to 2 to 5 ILm, an alloy powder was obtained. The apparent density, tap density, and ejection pressure of the obtained alloy powder were measured using an Amsler press machine. After compacting the powder at 1.2 t/cm' in a 15 kOe magnetic field to obtain a compact, 99.99wj% purity cl) Sintered in Ar at -1~1120°C for 2 hours and cooled to room temperature. Further, an aging treatment was performed at 650° C. for 2 hours to obtain the present alloy magnet. The results are shown in Table 2.

Example 3 An alloy having the following atomic percentage was weighed, melted at high frequency in argon, cast, and then molded by a stamp mill for 40 m.
After coarsely pulverizing the powder to esh or less, it was finely pulverized to 2 to 5 pm to obtain an alloy powder. The appearance of the obtained alloy powder is density, tap density,
The powder, whose extraction pressure was measured using an Amsler φ press, was molded at 1.0t/crn' in a 10kOe magnetic field to obtain a compact, and then molded in Ar with a purity of 99.99wt%.
It was sintered at 00°C for 2 hours and cooled to room temperature. Another 600
Aging treatment was performed at ℃ for 2 hours to obtain the present alloy magnet. The results are shown in Table 3.

Example 4 An alloy having the following atomic percentage was weighed, high-frequency melted in argon, and cast.
After coarsely pulverizing to Sh or less, finely pulverizing to 2 to 5 ILm, an alloy powder was obtained. The appearance of the obtained alloy powder is density, tap density,
Then, the powder whose extraction pressure was measured using an Amsler press machine was molded at 1.5t/ctn' in a 1okoe magnetic field to obtain a molded body.
toa.

℃ for 2 hours and cooled to room temperature. Furthermore, 650℃,
Aging treatment was performed for 2 hours to obtain the present alloy magnet. The results are shown in Table 4.

Example 5 An alloy having the following atomic percentage was weighed, high-frequency melted in argon, cast, and then stamped with a stamp mill for 40 me
After coarsely pulverizing the powder to 2 to 5 pm, the alloy powder was obtained. After molding in a magnetic field at 1 Ot/crn' to obtain a molded body, it was molded at 1120°C in Ar with a purity of 99.99 wt% at 2 Ot/crn'.
It was sintered for an hour and cooled to room temperature. Further, an aging treatment was performed at 650° C. for 2 hours to obtain the present alloy magnet.

The results are shown in Table 5.

In this way, as the experimental results of the above comparative test show, by adding a predetermined amount of additive element A to the FeBR alloy powder, the apparent density of the alloy powder as a starting material increases.
It can be seen that all of the Examples are significantly improved compared to the Comparative Examples. Accordingly, it was possible to increase the tap density during press molding, and it was also possible to considerably reduce the extraction pressure during punch extrusion.

Furthermore, the sintered alloy of the present invention is not only superior in terms of magnetic properties, but also has coercive force iHc, which is equal to or higher than that of conventional FeBR-based sintered magnets, as shown by the above experimental results. Demonstrates maximum energy product (BH) max, etc.

In addition, the permanent magnet of the present invention contains Cu, S, C, P, Ca, M mixed from raw materials, manufacturing processes, etc.
g * May contain elements (x) such as O, St, etc.
Cu3.5% or less, S2.0% or less, C4.0% or less,
If P is 3.0% or less, Ca is 4.0% or less, Mg is 4.0% or less, 0.02.0% or less, and Si is 5.0% or less, properties equivalent to or better than those of hard ferrite can be obtained. However, the element (
When X) exceeds the above content, the residual magnetic flux density (B r)
It cannot be used as a practical permanent magnet because of the decrease in

By partially replacing Fe, which is the main component of the Fe-B-R-A alloy of the present invention, with CO, the Curie point can be raised by one point and the temperature characteristics can be improved. In replacing Fe with CO, as the amount of Co replaced increases, the Curie point increases rapidly regardless of H, so the temperature characteristics can be improved by any amount depending on the amount of Co replaced. * Below 25% Co, other magnetic The Curie point is increased by one point without adversely affecting the characteristics, and the temperature coefficient of Br is 0.1%/° C. when Co is 5% or more. Further, the Co content is defined by the lower limit of Fe and is less than 25%. Co is effective even in small amounts (for example, 0.1 to 1%).

Also, Fe-B-R-A alloy or Fe-C of the present invention
The following additive elements M (M is Al,
Ti, V, Cr, Mn, Zr, Hf.

Coercive force can be increased by adding a predetermined amount of one or more of Nb, Ta, Mo, Ge, Sb, Sn, BitNi. This makes it a permanent magnet that can be used in high-temperature environments.

The amount of the additional element M is: AI 9.5% or less, Ti 4.5% or less, ■9.
5% or less, Cr 8.5% or less, Mn 8.0% or less,
Zr 5.5% or less, Hf 5.5% or less, Nb12
．． 5% or less, Ta1O, 5% or less, Mo 9.5% or less, Ge 7.0% or less, Sb 2.5% or less, Sn
3.5% or less, Bi 5.0% or less, Ni 8.0%
Below, W is 9.5% or less.

Here, when two or more types of M are used, the total amount of M is not more than % of the maximum value of the added elements, and each is not more than the above-mentioned predetermined value. If the content of M exceeds the predetermined value, the residual magnetic flux density deteriorates to less than B r 4 kG, so that it cannot be used as a practical permanent magnet.

Procedural amendment dated March 27, 1985 l Case description Patent Application No. 244791 of 1988 (
Filed on December 27, 1982) 2 Title of the invention Sintered magnet material 3 Relationship with the case of the person making the amendment Name of applicant Sumitomo Special Metals Co., Ltd. 4 Agent 5 Subject of amendment Detailed explanation of the invention in the specification Column 6: Contents of amendment The column for detailed explanation of the invention in the specification is amended as follows, as shown in the attached sheet.

(1) Page 5, lines 5-6, rCo is not used at all.”
"Do not use large amounts of rCo."

that's all

Claims (4)

[Claims] (1) 8 to 30% rare earth element E (however, R
is at least one kind of rare earth element including Y), and 2 to
The main components are 28% B and 65-82% Fe, and one or more additional elements A below the specified amount below.
Sintered magnet material characterized by containing: However, the additive element A is 0% of A, jio, 5%,
Zn 2.0%. In, 1.0%, Ag 2.0%, Sn 2.0%
, Pb 2.0%, and when two or more types of additive element A are included, additive element A
The content of A should be less than or equal to the maximum value of the above values of each additional element contained in A. (2) Rare earth element R with 8 to 30% atomic percentage (however, R
is at least one rare earth element including Y), 2-2
8%17) B, 65-82%c7) Fe, less than 25% Co (excluding 0% Co) as the main component, and also contains one or more additive elements A below the specified amount Sintered magnet material characterized by: However, the additive element A is 0.5% Li except A 0%.
, Zn 2.0%, In 1.0%, Ag 2.0%, Sn 2.0%, Pb 2.0%, and when two or more types of additive elements A are included, the additive element A
The content of A should be less than or equal to the maximum value of the above values of each additional element contained in A. (3) Rare earth element R with an atomic percentage of 8 to 30% (however, R
is at least one rare earth element including Y), 2-2
8% B, 65-82% 0) Fe as a main component, and a sintered magnet characterized by containing one or more additive elements A and M in the following predetermined amounts or less. Material: (a) However, additive element A is L, except for AO%.
i O, 5%, Zn 2.0%, In 1.0%, Ag 2.0%, Sn 2.0%, Pb 2.0%, and when it contains two or more types of A, the content of A shall be less than or equal to the maximum value of the above values of each additional element contained in A,
Additionally, the additional elements M (excluding MO%) are as follows: AI 9.5%, Ti 4.5%, ■ 9.5%, Cr 8.5%, Mn 8.0%, Zr 5.5%, Hf 5.5%, Nb 12.5%, Ta 10.5%, Mo 9.5%, Ge 7.0%, Sb 2.5%, Sn 3.5%, Bi 5.0%, Ni-8 , 0%, and W 9.5%, and when two or more types of M are included, the content of M is the amount of M contained.
be below the maximum value of the above values for each additional element. (4) 8 to 30% clay i element R in atomic percentage (however, R
is at least one rare earth element including Y), 2-2
The main components are 8% B, 65 to 82% Fe, and less than 25% Co (excluding 0% Co), as well as one or more additive elements A and additives each below the specified amount below. Sintered magnet material characterized by containing element M: (a) However, the additive element A is 0% Li, excluding A 0%.
5%, Zn 2.0%, In 1.0%, Ag 2.0%. Sn 2.0%, Pb 2.0%. and when it contains two or more types of A, the content of A shall be less than or equal to the maximum value of the above values of each of the added elements of the contained A, and the added element M (excluding M 0%), AI 9.5%, T i 4, 5%, ■ 9.5%,
Cr 8.5%, Mn8, 0%, Zr 5.5%, Hf 5. '
5%, Nb 12.5%, Ta 10.5%, Mo 9
．． 5%, Ge 7.0%, Sb 2.5%, Sn 3.5%, Bi 5.0%, Ni, 8.0%, and W 9.5%, and contains two or more types of M. In this case, the total amount of M is less than or equal to the maximum value of the above values of each additional element of M contained.