KR20190080748A - Rare earth magnet and production method thereof - Google Patents

Abstract

The present invention provides a rare earth magnet and a manufacturing method for the same. The rare earth magnet suppresses degradation of a coercive force in high temperature. The rare earth magnet includes: a main phase; and a grain boundary phase existing around the main phase. Whole composition is indicated by the equation (Ndx(Ce,La)(1-x-y)R1y)pFe(100-p-q-r-s)CoqBrM1s·(R2zR3wM21-z-w)t. (R1 is one or more kinds selected among rare earth elements except for Nd, Ce, and La, and R2 is one or more kinds selected among Pr, Nd, Pm, Sm, Eu, and Gd. R3 is one or more kinds selected among the rare-earth element except for R2, and M1 and M2 are predetermined elements. Also, 5.0<=p<=20.0, 0<=q<=8.0, 4.0<=r<=6.5, 0<=s<=2.0, 0<=t<=10.0, 0.4<=x<=0.8, 0<=y<=0.1, 0.5<=z<=0.8 and 0<=w<=0.1.) Also, La is contained in Ce at a mole fraction of 1/9 to three times.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a rare earth magnet,

The present disclosure relates to an R-Fe-B rare earth magnet (R is a rare earth element) and a manufacturing method thereof. The present disclosure relates to an R-Fe-B type rare-earth magnet having a suppressed decrease in coercive force particularly at high temperatures and a method for producing the same.

The R-Fe-B rare earth magnet has a main phase and an intergranular phase existing around the main phase. The main phase has a composition expressed by R ₂ Fe ₁₄ B and is in the magnetic phase. By this column phase, strong magnetism is manifested. On the other hand, the intergranular phase exists around the columnar phase and magnetically divides the columnar phases. The coercive force of the R-Fe-B rare earth magnet is increased by this magnetic separation.

Various attempts have been made to increase the self-segmentation effect. For example, Patent Document 1 discloses a rare earth magnet in which a rare earth magnet having a main phase and an intergranular phase is used as a precursor, and a reforming material is infiltrated into the precursor.

In the rare-earth magnet disclosed in Patent Document 1, the coercive force of the rare-earth magnet as a whole is increased by having an intermediate phase between the main phase and the grain boundary phase.

International Publication No. 2014 / 196605A1

R-Fe-B rare earth magnets have been used in various fields because of their high performance. Therefore, the R-Fe-B rare earth magnet is also used in a high temperature environment. Further, when the R-Fe-B rare earth magnet is used for a high output motor and a high output is maintained for a long time, the R-Fe-B rare earth magnet may become hot due to self heat generation of the motor.

It is known that when the R-Fe-B rare earth magnet becomes hot, the coercive force may be lowered.

From these results, the present inventors have found a problem that R-Fe-B rare earth magnets are required to have a lowered coercive force even at a high temperature. In this specification, the high temperature means a range of 130 to 170 占 폚, particularly 140 to 160 占 폚. The room temperature refers to a range of 20 to 25 占 폚. The R-Fe-B type rare-earth magnet refers to a magnet having a main phase and an intergranular phase existing around the main phase and including an phase whose main phase is represented by R ₂ Fe ₁₄ B.

The present disclosure has been made to solve the above problems. The present disclosure aims to provide an R-Fe-B rare earth magnet having a suppressed decrease in coercive force even at a high temperature, and a method for producing the same.

In order to achieve the above object, the inventors of the present invention have conducted intensive studies to complete the rare earth magnet of the present disclosure and a method for producing the rare earth magnet. The rare-earth magnet of the present disclosure and the manufacturing method thereof include the following embodiments.

&Lt; 1 >

The grain boundary phase existing around the main phase

Respectively,

The total composition is represented by the formula (Nd _x (Ce, La) _(1-xy) R ¹ _y ) _p Fe _(100-pqrs) Co _q B _r M ¹ _s (R ² _z R ³ _w M ² _{1 -zw} ) _t (where, R ¹ is at least one element selected from rare earth elements other than Nd, Ce, and La, R ² is at least one member selected from Pr, Nd, Pm, Sm, Eu and Gd, R ³ is R ² M ¹ is at least one element selected from Ga, Al, Cu, Au, Ag, Zn, In and Mn, and an inevitable impurity element, M ² is at least one element selected from the group consisting of R ² and by alloying with R ^3, R ² and R ³ _{z w} M alloying elements and inevitable impurity elements to the melting point of the ² _1-zw lower than the melting point of the R ^2, also

p, q, r, s and t are atomic%

5.0? P? 20.0,

0? Q? 8.0,

4.0? R? 6.5,

0? S? 2.0 and

0? T? 10.0

ego,

x, y, z and w have a molar ratio

0.4? X? 0.8,

0? Y? 0.1,

0.5? Z? 0.8 and

0? W?

), And is also represented by

The La is contained in an amount of 1/9 to 3 times the molar ratio of Ce

Rare earth magnets.

&Lt; 2 > The rare earth magnet according to < 1 >, wherein La is contained at a molar ratio of 1/9 to 2 times with respect to Ce.

&Lt; 3 > A magnetic recording medium according to &lt; 3 &gt;

Wherein t is 0.1? T? 10.0, and

Wherein the concentration of R ² is higher in the intermediate phase than in the main phase,

The rare-earth magnet described in the item <1> or <2>.

<4> The rare-earth magnet according to any one of <1> to <3>, wherein R ² is Nd.

<5> The rare-earth magnet according to <3> or <4>, wherein the concentration of R ² is 1.5 to 8.0 times higher in the main phase than in the intermediate phase.

<6> The rare-earth magnet according to any one of <3> to <5>, wherein the intermediate phase has a thickness of 2 to 100 nm.

<7> formula _{(Nd x (Ce, La)} (1-xy) R 1 y) p Fe (100-pqrs) Co q B r M 1 s ( single, R ¹ is a rare earth element other than Nd, Ce, and La M ¹ is at least one element selected from Ga, Al, Cu, Au, Ag, Zn, In, and Mn, and is an inevitable impurity element, and

p, q, r and s are atomic%

5.0? P? 20.0,

0? Q? 8.0,

4.0? R? 6.5 and

0? S? 2.0

ego,

When x and y are in a molar ratio

0.4? X? 0.8 and

0? Y? 0.1

), And preparing a molten metal containing La in a molar ratio of 1/9 to 3 times with respect to Ce,

Quenching the molten metal to obtain a thin band,

Compressing the plurality of the thin ribbons in a hot state to obtain a molded article, and

And compressing the molded body in hot state to obtain a compressed body

Included

A method of manufacturing a rare earth magnet.

<8> The method according to <7>, wherein the molten metal contains La at a molar ratio of 1/9 to 2 times the Ce.

R ² _z R ³ _w M ² _{1 -zw} wherein R ² is at least one element selected from Pr, Nd, Pm, Sm, Eu and Gd and R ³ is at least one element selected from rare earth elements other than R ² . and select at least one type of compound, M ² is by alloying with R ² and R ^3, R ² and R ³ _{z w} M alloying elements and inevitable impurity elements to the melting point of the ² _{1 -zw} lower than the melting point of the R ^2, z And w are molar ratios of 0.5? Z? 0.8 and 0? W? 0.1), a method of preparing a reforming material containing an alloy represented by the formula

Contacting the compression body and the modifying material to each other to obtain a contact body, and

The contacting body is heat-treated so that the melt of the reforming material is permeated into the inside of the compression body

Including,

&Lt; 7 > or < 8 >.

<10> The method according to <9>, wherein R ² is Nd.

<11> The method according to any one of <7> to <10>, wherein the compact is compressed at a strain rate of less than 0.001 / s to less than 0.1 / s, a reduction rate of 50 to 70% Lt; / RTI &gt;

According to the present disclosure, it is possible to provide a rare-earth magnet in which Nd, Ce and La coexist and the content ratio of Ce and La is within a predetermined range, whereby the decrease in coercive force at a high temperature is suppressed.

1 is a graph showing the content ratios of Nd, Ce and La.
Fig. 2 is a diagram schematically showing an aspect of the structure of the rare earth magnet according to the present disclosure. Fig.
3 is a view showing another embodiment of the structure of the rare-earth magnet according to the present disclosure.
4 is a graph showing the relationship between the temperature and the coercive force with respect to the samples of Example 15 and Comparative Example 1. Fig.
5 is a graph showing the relationship between temperature and residual magnetization for the samples of Example 15 and Comparative Example 1. Fig.
6 is a diagram showing a structure observation and a component analysis position of the sample of Example 6. Fig.
7 is a diagram showing the results of a structural observation and a component analysis of a sample (first field of view) of Example 6. Fig.
Fig. 8 is a diagram showing the results of the structural observation and the component analysis of the sample (second field of view) of Example 6. Fig.
Fig. 9 is a diagram showing a structure observation and a component analysis position for the sample of Example 12. Fig.
10 is a diagram showing the results of a structural observation and a component analysis of a sample (first field of view) of Example 12. Fig.
11 is a diagram showing a result of a structural observation and a component analysis of a sample (second field of view) of Example 12. Fig.
12 is a diagram showing a structure observation and a component analysis position of the sample of Example 17. Fig.
13 is a diagram showing a result of a structural observation and a component analysis of a sample (first field of view) of Example 17. Fig.
14 is a diagram showing a result of a structural observation and a component analysis of the sample (second visual field) of Example 17. Fig.
15 is a view showing an example of a particle diameter t of a crystal grain with respect to the sample of Example 39. Fig.
16 is a view showing an example of a grain size t of crystal grains for the sample of Example 40. Fig.
17 is a diagram showing an example of a particle diameter t of a crystal grain with respect to the sample of Example 6. Fig.
18 is a diagram showing an example of a particle diameter t of a crystal grain with respect to the sample of Example 12. Fig.
19 is a diagram showing a result of a tissue observation and a component analysis position for the sample of Example 39. Fig.
20 is a diagram showing the result of the component analysis at the position indicated by the white line in Fig.
Fig. 21 is a diagram showing a result of a tissue observation and a component analysis position for the sample of Example 40. Fig.
22 is a diagram showing the result of the component analysis at the position indicated by the white line in FIG.
23 is a diagram showing a result of a tissue observation and a component analysis position for the sample of Example 6. Fig.
Fig. 24 is a diagram showing the result of the component analysis at the position indicated by the white line in Fig. 23. Fig.
Fig. 25 is a diagram showing a result of a tissue observation and a component analysis position for the sample of Example 12. Fig.
26 is a diagram showing the result of the component analysis at the position indicated by the white line in Fig.

Hereinafter, embodiments of the rare-earth magnet and the manufacturing method thereof according to the present disclosure will be described in detail. The embodiments described below do not limit the rare-earth magnet according to the present disclosure and the manufacturing method thereof.

In the R-Fe-B rare earth magnet, 1) the diameter of the main phase is made small, 2) the anisotropic magnetic field of the main phase is made high, and 3) the coercive force for magnetically dividing the main phases is improved.

In order to reduce the grain size of the columnar phase, the R-Fe-B type rare-earth magnet is nanocrystallized by liquid quenching or the like. Thereby, a large amount of R ₂ Fe ₁₄ B phase exists as a main phase in the R-Fe-B type rare-earth magnet, and grain boundary phase exists around the periphery of the main phase. In the grain boundary phase, there are an R rich phase containing an excessive amount of R and a small amount of magnetic phase (for example, RFe ₂ phase) containing Fe.

The Nd ₂ Fe ₁₄ B phase has a high anisotropic magnetic field at room temperature, but has a Curie point of 320 ° C, which is not so high. Therefore, even at the Curie point, the anisotropic magnetic field of the Nd ₂ Fe ₁₄ B phase is lowered at a high temperature. On the other hand, the Fe-containing magnetic phase (for example, RFe ₂ phase, etc.) is paramagnetic at a temperature higher than room temperature, but is likely to propagate magnetic spin interaction between Nd ₂ Fe ₁₄ B phases (between crystal grains) . When a large amount of Nd ₂ Fe ₁₄ B phase is present as the columnar phase, the coercive force is high at room temperature because the effect of the magnetic phase including Fe in the grain boundary phase is small. However, at high temperatures, the magnetic phase containing Fe in the grain boundary phase has the effect of propagating the magnetic spin interaction between Nd ₂ Fe ₁₄ B phases (columnar phases). As a result, the grain size of the columnar phase becomes apparently large, and the effect of nanocrystallization of the columnar phase is likely to deteriorate. As a result, the coercive force is rapidly lowered.

When the R of the R-Fe-B rare earth magnet includes Nd, Ce and La, the anisotropic magnetic field of (Nd, Ce, La) ₂ Fe ₁₄ B is Nd ₂ Fe ₁₄ B Of the anisotropic magnetic field. Hereinafter, the R-Fe-B rare earth magnet including Nd, Ce and La may be referred to as "(Nd, Ce, La) -Fe-B rare earth magnet".

Although it is not bound by theory, in the (Nd, Ce, La) -Fe-B rare earth magnets, when the content ratio of Ce and La is within a predetermined range, as compared with the Nd-Fe-B rare earth magnet, The stability of the magnetic phase (such as RFe ₂ phase) containing Fe is deteriorated. As a result, in the (Nd, Ce, La) -Fe-B rare earth magnet, Fe in the grain boundary phase tends to contribute to the formation of a phase other than the magnetic phase containing Fe. Examples of the phase other than the magnetic phase containing Fe include CeFe ₂ phase and the like.

(Nd, Ce, La) ₂ Fe ₁₄ B phase is generated, thereby increasing the total number of main phases. As a result, the coercive force of the (Nd, Ce, La) -Fe-B rare earth magnet as a whole is suppressed by supplementing the fact that Nd is substituted by Ce and La to decrease the anisotropic magnetic field. This coercive force improvement is remarkable at high temperatures. Further, although not limited to theory in the present specification, Ce or La exist in the (Nd, Ce, La) ₂ Fe ₁₄ B phase in the Nd on the Nd ₂ Fe ₁₄ B phase.

Further, when a rare earth magnet of (Nd, Ce, La) -Fe-B system is used as a precursor and a reforming material containing R ² is infiltrated into the precursor, depending on the penetration amount of the alloy in the reforming material, Between the intergranular phases, an intermediate phase is generated.

It is considered that a part of Ce and / or La existing in the main phase of the precursor is substituted with R ² , though not bound to the theory, to generate a middle phase. Therefore, in the intermediate phase, the anisotropic magnetic field in the intermediate phase is higher than the anisotropic magnetic field in the main phase of the precursor in that the concentration of R ² is higher than in the main phase of the precursor. When the temperature becomes high, the anisotropic magnetic field of the intermediate phase lowers. However, even at a high temperature, the anisotropic magnetic field of the intermediate phase is higher than the anisotropic magnetic field of the main phase of the precursor because the concentration of R ² is higher than that of the main phase of the precursor. As a result, it contributes to suppression of coercive force reduction.

The inventors of the present invention have discovered that R-Fe-B type rare-earth magnets can suppress a decrease in coercive force at high temperatures.

The constituent requirements of the rare-earth magnet and the manufacturing method thereof according to the present disclosure based on these findings will be described next.

"Rare earth magnets"

First, constituent requirements of the rare-earth magnet of the present disclosure will be described.

<Whole composition>

Overall composition of the rare-earth magnet of the present disclosure, expression _{(Nd x (Ce, La)} (1-xy) R 1 y) p Fe (100-pqrs) Co q B r M 1 s · (R 2 z R 3 w M ² _1-zw ) _t .

In the above formula, (R ² _z R ³ _w M ² _{1 -zw} ) _t represents a composition derived from the following modifier. If it does not penetrate the modifier, and t = 0, the entire composition of the rare-earth magnet of the present disclosure _{(Nd x (Ce, La)} (1-xy) R 1 y) p Fe (100-pqrs) Co q B r M ¹ _s .

On the other hand, in the case of infiltration the modifier, t is a positive value other than _{0, (Nd x (Ce,} La) (1-xy) R 1 y) p Fe (100-pqrs) Co q B r M 1 s Indicates the composition of the rare earth magnet precursor.

In the above formula, Nd is neodymium, Ce is cerium, La is lanthanum, R ¹ is at least one rare earth element other than Nd, Ce and La, Fe is iron, Co is cobalt and B is boron. M ¹ is at least one element selected from Ga, Al, Cu, Au, Ag, Zn, In, and Mn, and is an inevitable impurity element. Ga is gallium, Al is aluminum, Cu is copper, Au is gold, Ag is silver, Zn is zinc, In is indium, and Mn is manganese. R ² is at least one selected from Pr, Nd, Pm, Sm, Eu and Gd. Pr is praseodymium, Nd is neodymium, Pm is promethium, Sm is samarium, Eu is europium, and Gd is gadolinium. M ² is the alloying elements and inevitable impurity elements of the R ² and R ³ and by the alloying, the melting point of the R ² R ³ _{z w} M ² _1-zw, lower than the melting point of the R ^2.

In this specification, the rare earth element is 17 elements of Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu. Of these, Sc, Y, La and Ce are light rare earth elements. Pr, Nd, Pm, Sm, Eu and Gd are intermediate rare earth elements. Tb, Dy, Ho, Er, Tm, Yb and Lu are heavy rare earth elements. Further, in general, the rare earth rare earth element is high in scarcity and the light rare earth element is low in scarcity. The scarcity of the intermediate rare earth element is between the heavy rare earth element and the light rare earth element.

Next, p, q, r, s, and t, and x, y, z, and w will be described. The following description will be directed to the case where the reforming material is infiltrated. In the case where the reforming material is not impregnated, it is assumed that the "rare earth magnet precursor" is replaced with "rare earth magnet", and the description about the matters derived from the modifying material is omitted.

In the rare earth magnet precursor, p is the total content of Nd, Ce, La and R ¹ , q is the content of Co, r is the content of B (boron), and s is the content of M ¹ . Regarding matters derived from the reforming material, t is a penetration amount of the alloy in the reforming material to the rare earth magnet precursor, and is a total content of R ² , R ³ and M ² . The values of p, q, r, s and t are each atomic%.

In the rare earth magnet precursor, the values of x and y are the following content ratios (molar ratios), respectively. x represents the content ratio of Nd to the total content of Nd, Ce, La and R ¹ . y represents the content ratio of the R ^1, based on the total content of Nd, Ce, La and R ^1. With respect to matters derived from the modifier, the values of z and w are the following content ratios (molar ratios), respectively. and z represents the content ratio of R ² to the total content of R ² , R ³ and M ² . and w represents the content ratio of R ³ to the total content of R ² , R ³ and M ² .

The constituent elements of the rare earth magnet precursor represented by the above formula will be described below.

<Nd>

Nd is an essential component for the rare earth magnet precursor of the present disclosure. By the inclusion of Nd, high magnetization can be exhibited at room temperature and high temperature. Further, at room temperature, the Nd ₂ Fe ₁₄ B phase has a high anisotropic magnetic field.

<Ce>

Ce is an essential component of the rare earth magnet precursor of the present disclosure. When Nd in the main phase (Nd ₂ Fe ₁₄ B phase) is substituted with Ce, a magnetic phase containing Fe in the grain boundary phase, that is, a CeFe ₂ phase, tends to be generated. The CeFe ₂ phase is paramagnetic and is expected to have an effect of propagating the magnetic spin interaction between the main phases, thereby lowering the coercive force. In order to suppress the lowering of the coercive force, it is necessary to lower the stability of the magnetic phase including Fe in the grain boundary phase.

Ce may be trivalent or tetravalent. Although not bound by theory, many Ce are trivalent by the action of La. In the trivalent Ce, since 4f electrons are localized, magnetization is improved and preferable.

<La>

La is an essential component of the rare earth magnet precursor of the present disclosure. When Nd in the main phase (Nd ₂ Fe ₁₄ B phase) is substituted with La, the stability of the magnetic phase including Fe in the grain boundary phase is lowered. This is because the compounds of transition metals such as La and Fe are thermodynamically unstable as a whole, and therefore, they are not mixed. That is, by adding La, an effect of suppressing the formation of the RFe ₂ phase is expected. Therefore, La contributes greatly to suppression of coercive force reduction. In addition, La is preferably lower in cost than Nd. Further, when Ce is added, a CeFe ₂ phase tends to be generated, and the coercive force is lowered. However, by adding La at the same time as Ce, generation of the CeFe ₂ phase is suppressed, and propagation of magnetic spin interaction between the main phase particles is suppressed.

<Content Ratio of Nd, Ce and La>

As described above, x is the content ratio of Nd. Ce than ₂ Fe ₁₄ B phase and the La ₂ Fe ₁₄ B on, has high saturation magnetization and the anisotropic magnetic field in the Nd ₂ Fe ₁₄ B. From this, it is easy to obtain a desired magnetization and coercive force in the rare-earth magnet of the present disclosure if x is 0.40 or more. From this viewpoint, x may be 0.45 or more, 0.50 or more, or 0.55 or more. On the other hand, if x is 0.80 or less, the content ratio of Ce and La is too small, so that the effect of Ce and La is not hardly obtained. From this viewpoint, x may be 0.75 or less, 0.70 or less, or 0.65 or less.

In the rare earth magnet precursor, the La content is 1/9 to 3 times the molar ratio with respect to the Ce content. 1 is a graph showing the content ratios of Nd, Ce and La. In Fig. 1, the straight line indicated by (1) represents a composition in which the content of La is 1/9 times the molar ratio with respect to the Ce content. (2) represents a composition in which the content of La is 1/3 times the molar ratio with respect to the content of Ce. (3) represents a composition in which the content of La is 2/3 times the molar ratio with respect to the content of Ce. (4) represents a composition in which the content of La is three times the molar ratio with respect to the content of Ce.

In other words, the following is obtained. (1) represents a composition of Ce: La = 1: 1/9. (2) represents a composition of Ce: La = 1: 1/3. (3) represents a composition of Ce: La = 1: 2/3. (4) represents a composition of Ce: La = 1: 3.

As described above, since the content ratio x of Nd is 0.4 to 0.8, the composition of the rare earth magnet precursor of the present disclosure is such that the region lying between &quot; Nd80 &quot; and &quot; Nd40 &quot; Appear as overlapping portions of the region lying between the straight lines 4.

If the La content is 1/9 times or more as large as the Ce content, the desired magnetization can be obtained at room temperature and high temperature. From this point of view, 1/8 times or more is preferable, and 1/7 or more times is more preferable. On the other hand, when the content of La is 3 times or less as much as the content of Ce, the stability of the Fe-containing magnetic phase (such as RFe ₂ phase) is deteriorated by substituting Ce and / or La for Nd in the grain boundary phase , The content (volume ratio) of the magnetic phase containing Fe is lowered. As a result, the intergranular phase suppresses the effect of propagating the magnetic spin interaction between the columnar phases, and suppresses the decrease of the coercive force at high temperatures. From this viewpoint, it is preferably 5/2 times or less, more preferably 2 times or less.

<R ¹ >

R ¹ is at least one element selected from rare earth elements other than Nd, Ce and La. The rare-earth magnet of the present disclosure contains Nd, Ce and La as essential components. In the raw materials of these essential components, it is difficult to have no rare-earth element R ¹ other than Nd, Ce and La. However, if the value of the content ratio y of R ¹ is 0 to 0.1, the characteristics of the rare-earth magnet of the present disclosure may be considered to be substantially equal to the value of y when the value of y is 0.

The value of y may be 0.01 or more, 0.02 or more, 0.03 or more, 0.04 or more, or 0.05 or more, because excessively increasing the purity of the raw material of the essential ingredient causes an increase in production cost. On the other hand, the value of y is preferably as low as possible, and is not more than 0.09, not more than 0.08, not more than 0.07, or not more than 0.06, as long as the production cost does not increase.

When the total content p of Nd, Ce, La and R ¹ is 5.0 atomic% or more, the main phase represented by (Nd, Ce, La) ₂ Fe ₁₄ B does not become difficult to be generated. P may be 7.0 atomic% or more, 9.0 atomic% or more, 11.0 atomic% or more, or 13.0 atomic% or more from the viewpoint of ease of generation of the main phase represented by (Nd, Ce, La) ₂ Fe ₁₄ B. On the other hand, when p is 20.0 atomic% or less, the existence ratio (volume ratio) of the grain boundary phase is not excessive. From the viewpoint that the existence ratio of the intergranular phase does not become excessive, it may be 19.0 atomic% or less, 18.0 atomic% or less, or 17.0 atomic% or less.

<B>

B affects the content of the main phase and the content of the magnetic phase including Fe in the grain boundary phase. When the content of B is too small, the main phase represented by (Nd, Ce, La) ₂ Fe ₁₄ B is hardly produced. When the content r of B is 4.0 atomic% or more, the generation of the main phase represented by (Nd, Ce, La) ₂ Fe ₁₄ B does not become difficult. From this viewpoint, r may be 4.5 atomic% or more, 5.0 atomic% or more, or 5.5 atomic% or more. On the other hand, if the content r of B is excessive, a magnetic phase including Fe such as RFe ₄ B ₄ phase is likely to be generated on the grain boundary phase. When r is 6.5 atomic% or less, a large amount of the? -Fe phase is hardly produced. From this viewpoint, r may be 6.3 atomic% or less or 6.0 atomic% or less.

<Co>

Co is an element which can be substituted with Fe in the columnar phase, grain boundary phase and intermediate phase. In the present specification, when Fe is described, a part of Fe can be substituted with Co. For example, a part of Fe on the (Nd, Ce, La) ₂ Fe ₁₄ B phase is substituted with Co and becomes (Nd, Ce, La) ₂ (Fe, Co) ₁₄ B phase. The magnetic phase (R ² Fe ₁₇ phase or the like) containing Fe in the grain boundary phase is a magnetic phase (R ₂ (Fe, Co) ₁₇ phase or the like) in which a part of Fe is substituted with Co.

As described above, since a part of Fe is substituted with Co, the Curie point of each phase is improved. In the case where improvement of the Curie point is not desired, Co may not be contained, and Co is not essential. When the content q of Co is 0.5 atomic% or more, the improvement of the Curie point is substantially confirmed. From the viewpoint of improvement of the Curie point, it may be 1.0 atomic% or more, 2.0 atomic% or more, 3.0 atomic% or more, or 4.0 atomic% or more. On the other hand, since Co is expensive, from an economic point of view, the content q of Co may be 8.0 atomic% or less, 7.0 atomic% or 0.6 atomic% or less.

<M ¹ >

M ¹ may be contained in an amount not to impair the properties of the rare-earth magnet of the present disclosure. M ¹ may contain an inevitable impurity element. Inevitable impurity elements can not avoid the inclusion of impurity elements contained in raw materials of rare earth magnets or impurity elements which are mixed in the manufacturing process or impurities that cause remarkable increase in manufacturing cost Element. The impurity element or the like mixed in the manufacturing process includes an element which is contained within a range that does not affect the magnetic properties, depending on the manufacturing conditions.

Examples of the element which can be contained within a range that does not impair the characteristics of the rare-earth magnet of the present disclosure include Ga, Al, Cu, Au, Ag, Zn, In and Mn.

Ga, Al, Zn, In, Au, Ag and Cu lower the melting point of the intergranular phase present in the inside of the thin film obtained by the liquid quenching method or the like. Thus, these elements may be contained in order to obtain a compact from a plurality of thin ribbons and / or to obtain a compact from a compact for the purpose of improving the life of the mold, but it is not essential. If the upper limit of the M ¹ content is not exceeded, these elements do not substantially affect the magnetic properties. These elements may be regarded as inevitable impurity elements in terms of magnetic properties.

Mn has been substituted with a portion of the _{(Nd, Ce, La) 2} Fe 14 B phase of Fe, contributes to the stabilization on the _{(Nd, Ce, La) 2} Fe 14 B.

If the content s of M ¹ is 2.0 atomic% or less, the magnetic properties of the present disclosure are not impaired. From this viewpoint, the content s of M ¹ may be 1.5 atomic% or less, 1.0 atomic% or 0.5 atomic%.

Even when M ¹ does not contain Ga, Al, Cu, Au, Ag, Zn, In, and Mn, since the inevitable impurity element can not be present, the lower limit of the content s of M ¹ is 0.05 atomic% , 0.1 atom% or 0.2 atom%, there is no practical problem.

Each of the values of p, q, r, and s explained so far is equivalent to that of a normal R-Fe-B rare earth magnet.

<Fe>

Fe is the remainder of the Nd, Ce, La, R ¹ , Co, B, and M ¹ described so far, and the Fe content (atomic%) is represented by (100-pqrs). When p, q, r and s are in the ranges described so far, columnar and intergranular phases are obtained. Further, when a rare-earth magnet having a columnar phase and an intergranular phase is used as a precursor and the precursor is sufficiently infiltrated with the reforming material, an intermediate phase is obtained. Hereinafter, the columnar phase, grain boundary phase and intermediate phase will be described.

&Lt; Column, intergranular phase and intermediate phase >

Fig. 2 is a diagram schematically showing an aspect of the structure of the rare earth magnet according to the present disclosure. Fig. 3 is a view showing another embodiment of the structure of the rare-earth magnet according to the present disclosure.

In the embodiment shown in Fig. 2, the rare earth magnet 100 of the present disclosure has a columnar phase 10 and an intergranular phase 20. In the embodiment shown in Fig. 3, the rare earth magnet 100 of the present disclosure has, in addition to the columnar phase 10 and the intergranular phase 20, a further intermediate phase 30.

The embodiment shown in Fig. 2 is confirmed when the reforming material is not infiltrated or when a very small amount of the reforming material is infiltrated. The rare earth magnet 100 of the embodiment shown in Fig. 2 is used as a rare earth magnet precursor to permeate the modifier. The embodiment shown in Fig. 3 is confirmed when a sufficient amount of the reforming material is infiltrated into the rare earth magnet precursor.

The rare earth magnet 100 may contain an image (not shown) other than the columnar phase 10, the intergranular phase 20 and the intermediate phase 30. Examples of the phase other than the columnar phase 10, the intergranular phase 20 and the intermediate phase 30 include an oxide, a nitride and an intermetallic compound.

The characteristics of the rare-earth magnet 100 are mainly exhibited by the columnar phase 10, the intergranular phase 20 and the intermediate phase 30. Most of the phases other than the columnar phase 10, the intergranular phase 20 and the intermediate phase 30 are impurities. Therefore, the total content of the columnar phase 10, the intergranular phase 20, and the intermediate phase 30 with respect to the rare earth magnet 100 is preferably 95 vol% or more, more preferably 97 vol% or more, % Or more is more preferable.

The columnar phase 10 is nanocrystallized. The term "nanocrystallized" means that the average diameter of the columnar phase 10 is 1 to 1000 nm. The average particle diameter may be 10 nm or more, 50 nm or more, 100 nm or more, 900 nm or less, 700 nm or less, 500 nm or less or 300 nm or less.

The "average particle diameter" is, for example, an average value of the length t in the longitudinal direction of the columnar body 10 shown in FIG. For example, a certain region is defined on a scanning electron microscope or a transmission electron microscope of the rare earth magnet 100, and an average value of the length t of each of the columnar phases 10 existing in the certain region is calculated, Particle diameter &quot;. When the cross-sectional shape of the columnar phase 10 is elliptical, the length of the major axis is denoted by t. When the cross-section of the columnar surface is a square, the diagonal length of the long side is t. In the case of the embodiment shown in Fig. 3, t is set, including the intermediate image 30. This is because the intermediate phase 30 is derived from the columnar phase 10 as described later.

When the rare earth magnet 100 shown in FIG. 2 is made into a rare earth magnet precursor (hereinafter, sometimes referred to as "precursor 100") and the modified material is infiltrated into the rare earth magnet precursor, Reaches the interface between the columnar phase (10) and the intergranular phase (20). Then, R ² in the modifying material penetrates into the interior of the columnar phase 10 from the intergranular phase 20 to form the intermediate phase 30 as shown in Fig.

The intergranular phase 20 exists around the columnar phase 10. The intermediate phase 30 is placed between the columnar phase 10 and the intergranular phase 20. Formation of the intermediate phase 30 will be described from the viewpoint of the composition of the reforming material.

<R ² , R ³ and M ² >

The modifier contains an alloy having a composition expressed by R ² _z R ³ _w M ² _{1 -zw} . On the other hand, the precursor 100 has a composition represented by (Nd _x (Ce, La) _(1-xy) R ¹ _y ) _p Fe _(100-pqrs) Co _q B _r M ¹ _s .

R ² is at least one selected from Pr, Nd, Pm, Sm, Eu and Gd. R ³ is at least one selected from rare earth elements other than R ² . And, M ² is R ² and the alloying elements and inevitable impurity elements to the melting point of the R ³ and, R ² R ³ _{z w} ² M _{1 -zw} by alloying, lower than the melting point of the R ^2.

Precursor 100 is a rare earth element and mainly contains Nd, Ce and La. On the other hand, the alloy of the modification material is a rare earth element mainly containing an R ² at least one selected from Pr, Nd, Pm, Sm, Eu and Gd.

R ^{2 of the} reforming material and Nd, Ce, and La of the precursor 100 are different from one another in the kind of rare earth element. Therefore, R ² penetrates into the columnar phase 10, . Therefore, the concentration of R ² becomes higher in the intermediate phase 30 than in the columnar phase 10. Although not bound by theory, it is believed that the reason for the infiltration of R ^{2 into} the columnar phase 10 is as follows.

The rare earth element in the reforming material is hardly permeated into the columnar phase 10 when the alloy in the reforming material contains the same rare earth element as the columnar phase 10 when the reforming material is infiltrated into the precursor 100. [ For example, when a reforming material containing an Nd-Cu alloy is infiltrated into the Nd-Fe-B rare earth magnet precursor, the Nd in the reforming material tends to remain in the intergranular phase 20 and the phase of Nd ₂ Fe ₁₄ B Phase).

On the other hand, when the alloy in the reforming material mainly contains rare earth elements different from those of the columnar phase 10, the rare earth elements in the reforming material tend to permeate the columnar phase 10. For example, when a reforming material containing an Nd-Cu alloy is infiltrated into a (Nd, Ce, La) -Fe-B based rare earth magnet, the presence of Ce and La causes Nd in the reforming material to react with the main phase ). From the viewpoint of improving the saturation magnetization and the anisotropic magnetic field of the intermediate phase 30 to a good balance, R ² is preferably Nd.

The composition of the alloy in the _modifier is represented by R ² _z R ³ _w M ² _{1 -zw} . R ³ is at least one selected from rare earth elements other than R ² . The rare earth element contained in the alloy in the reforming material is R ^2, but it is difficult to have no rare earth element R ³ other than R ² . However, if the value of the content ratio w of R ³ is 0 to 0.1, the property as a modifying material may be considered to be substantially equal to the value of w when the value of w is 0.

The value of w is ideally close to 0, but the value of w may be 0.01 or more, 0.02 or more, 0.03 or more, 0.04 or more, or 0.05 or more. On the other hand, the value of w is preferably as low as possible as long as it does not cause an increase in manufacturing cost, and may be 0.09 or less, 0.08 or less, 0.07 or less, or 0.06 or less.

Expression of the total composition of _{(Nd x (Ce, La)} (1-xy) R 1 y) p Fe (100-pqrs) Co q B r M 1 s · (R 2 z R 3 w M 2 1 -zw) t , The value of t corresponds to the penetration amount (atomic%) of the alloy in the modifying material with respect to the precursor 100. The value of t changes the concentration of R ^{2 in} the intermediate phase 30 and the thickness of the intermediate phase 30.

In FIG. 3, if the concentration of R ² is 1.5 times or more higher in the intermediate phase 30 than in the columnar phase 10, self-segmentation can be clearly recognized. On the other hand, even if the concentration of R ² is 8.0 times higher in the intermediate phase 30 than in the columnar phase 10, the effect of magnetic division is not saturated. Therefore, the concentration of R ² is preferably 1.5 to 8.0 times higher in the intermediate phase 30 than in the columnar phase 10. The concentration of R ² may be 1.5 to 5.0 times higher or 1.5 to 3.0 times higher.

In order to clearly recognize the function as the intermediate phase 30, the thickness of the intermediate phase 30 is preferably 2 nm or more, more preferably 10 nm or more, and still more preferably 20 nm or more. On the other hand, the thickness of the intermediate phase 30 depends on the infiltration amount of the reforming material. Since the modifier contains M ² that does not contribute to magnetization, if the amount of penetration is too large, the volume fraction of the intergranular phase increases and the magnetization of the rare-earth magnet 100 decreases. From this viewpoint, the thickness of the intermediate phase 30 is preferably 100 nm or less, more preferably 70 nm or less, and still more preferably 40 nm or less.

&Quot; Manufacturing method &quot;

Next, a method of manufacturing the rare-earth magnet of the present disclosure will be described.

<Preparation of molten metal>

Equation _{(Nd x (Ce, La)} (1-xy) R 1 y) p Fe (100-pqrs) is represented by Co _q B _r M ¹ _s, also 1/9 to 3 with respect to Ce, La mole ratio Prepare the molten metal contained in the vessel. Alternatively, a molten metal containing La in a molar ratio of 1/9 to 2 times with respect to Ce may be prepared. Nd, Ce, La, R ¹ , Fe, Co, B and M ¹ , and x, y, p, q, r and s are the same as those of the rare earth magnet. Further, in the preparation of the molten metal or in a subsequent step, when a specific component is reduced, the portion may be estimated.

There is no limitation on the method of preparing the molten metal, and for example, the high-frequency melting of the raw material may be mentioned. The molten metal is preferably prepared in an inert gas atmosphere in order to prevent oxidation of the raw material during melting and the molten metal in the oil.

<Fabrication of Park>

The molten metal is quenched to obtain a thin ribbon. There is no particular limitation on the quenching method as long as the core phase in the ribbon can be nanocrystallized. For example, a liquid quenching method. Typically, the cooling rate of the molten metal may be 1 × 10 ² K / sec or more, 1 × 10 ³ K / sec or more, 1 × 10 ⁴ K / sec or more, and 1 × 10 ^{4 7} K / sec or less, 1 x 10 ⁶ K / s or less, or 1 x 10 ⁵ K / s or less.

As a condition of the liquid quenching method, for example, a method of discharging a molten metal toward a copper ingot in an inert gas atmosphere reduced to 50 kPa or less to obtain a thin film can be mentioned, but the present invention is not limited thereto.

The molten metal discharge temperature may be typically 1300 ° C or higher, 1350 ° C or higher, or 1400 ° C or higher, or 1600 ° C or lower, 1550 ° C or 1500 ° C or lower.

The peripheral velocity of the single roll may be 20 m / s or more, 24 m / s or 28 m / s or more, 40 m / s or less, 36 m / s or 32 m / s or less.

&Lt; Production of molded article >

The thin strip obtained by liquid quenching is hot pressed to obtain a molded article. The formed body is obtained from a plurality of thin ribbons. The method of compression is not particularly limited, and for example, a die is charged in a die and hot-pressed. Before the hot press, the strip may be pulverized to 10 탆 or less. The temperature at the time of hot pressing may be the temperature at which the formed body is obtained, but it may be a temperature at which a part of the grain boundary phase in the thin film is melted. That is, the thin strip may be sintered in liquid phase. The atmosphere in the hot press is preferably an inert gas atmosphere in order to prevent oxidation of the thin film and the molded article. Further, in hot pressing, powder obtained by pulverizing the thin strip may be subjected to milling to obtain a green compact, and then the green compact may be sintered (including liquid-phase sintering).

The pressure at the time of hot pressing may be typically 200 MPa or more, 300 MPa or more, 350 MPa or more, 600 MPa or less, 500 MPa or less or 450 MPa or less.

The temperature at the time of hot pressing may be typically 550 占 폚 or higher, 600 占 폚 or higher, 630 占 폚 or higher, 750 占 폚 or lower, 700 占 폚 or 670 占 폚 or lower.

The pressing time at the time of hot pressing may be typically 5 seconds or more, 20 seconds or 40 seconds or more, 120 seconds or less, 100 seconds or 80 seconds or less.

&Lt; Production of Compressed Body >

The above-mentioned molded body is further subjected to hot working in hot state to obtain a pressed body (plastic-worked body). There is no particular limitation in the method of hot-rolling (hereinafter, simply referred to as &quot; steel working &quot;) as long as an anisotropic compact is obtained. For example, there is a method in which a formed body is charged into an ultra-economical mold and a steel body is processed at a reduction ratio of 10 to 75%. Examples of the method of machining steel include upsetting and backward extrusion. The reduction rate may be set so as to obtain desired anisotropy. The temperature at the time of processing the steel may be set so that the compressed body is not destroyed and the crystal grains in the compressed body are not coarsened.

Typically, the reduction rate during steel processing may be 10% or more, 30% or more, 50% or more, 60% or more, 75% or less, 70% or less or 65% or less.

The temperature during steel processing may be 650 ° C or higher, 700 ° C or higher, or 720 ° C or higher, or 850 ° C or lower, 800 ° C or 770 ° C or lower.

The strain rate during steel processing may be 0.001 / s or more, 0.01 / s, 0.1 / s or 1.0 / s, 10.0 / s, 5.0 / s or 3.0 / s.

Although not bound by theory, it is believed that the following cases have occurred in the interior of a molded article during steel working. The formed body has a columnar phase 10 and an intergranular phase 20 existing around the columnar phase 10 (see Fig. 2). When the shaped body is subjected to the steel working, the columnar body 10 is deformed. At this time, due to the deformation, it is easy to generate a portion in which at least some of the columnar phases 10 are in direct contact with each other in the columnar phase 10. This contact portion can be a starting point of the grain growth of the columnar phase 10. If the deformation rate at the time of steel processing is low, the columnar phase 10 tends to grow at the contact portion as a starting point. Since the machining of steel is carried out in the hot state, the fact that the deformation rate is low means that the above-mentioned contact portion has a high temperature over a long period of time. Then, atom diffusion occurs through the contact portion, and the columnar phase 10 grows. On the other hand, in the initial stage of steel working, Ce and La, in particular La, are discharged from the columnar phase 10 to the intergranular phase 20. When Ce and La are discharged, Ce and La enter between the columnar phases 10 when the columnar phase 10 is deformed, and generation of the aforementioned contact portions is suppressed. Further, by the discharge of Ce and La, the melting point of the intergranular phase 20 is lowered. The steel processing is performed at a temperature at which at least one of the intergranular phases 20 is melted. By lowering the melting point of the intergranular phase 20, the melt viscosity of the intergranular phase 20 at the time of steel working is lowered. As a result, the columnar phase 10 during deformation tends to rotate in the melt, and the columnar phase 10 is liable to be oriented in a specific direction. In this respect, when the deformation rate is low, it is possible to suppress the grain growth of the columnar phase 10, suppressing the coercive force from being lowered, and suppressing the coercive force even when the deformation rate is in the range of 0.001 / The magnetization is improved. From this viewpoint, the strain rate may be 0.001 / s or more and 0.008 / s or less, or 0.001 / s or more and 0.005 / s or less.

The compact thus obtained may be used as it is as a rare earth magnet, and the compact may be used as a rare earth magnet precursor to carry out the following step.

<Preparation of Reforming Material>

A modifier containing an alloy having the composition represented by the formula R ² _z R ³ _w M ² _{1 -zw} is prepared. R ² and R ³ , and w are the same as those of the rare-earth magnet.

M ² is R ² and the alloying elements and inevitable impurity elements, by alloying of the R ^3, R ² lower than the melting point of the R ³ _{z w} M ² _{1 -zw} the melting point of the R ^2. Thereby, the alloy in the modifying material can be melted without excessively increasing the temperature of the heat treatment to be described later. As a result, the rare earth magnet precursor can penetrate the rare earth magnet precursor without alloying the structure of the rare earth magnet precursor. M ² may contain an inevitable impurity element. An inevitable impurity element refers to an impurity element which can not be avoided, such as an impurity element contained in a raw material, or causes a remarkable increase in manufacturing cost in order to avoid it.

M ² is preferably at least one element selected from Cu, Al and Co, and an inevitable impurity element. Cu, Al, and Co have a small adverse influence on the magnetic properties and the like of the rare-earth magnet.

R ² _z R ³ _w M ² As the alloy of the composition represented by _{1 -zw,} Nd-Cu alloy, Pr-Cu alloy, Nd-Pr-Cu alloy, Nd-Al alloy, Pr-Al alloy, Nd-Pr- Al alloys, Nd-Co alloys, Pr-Co alloys, and Nd-Pr-Co alloys.

The content ratio z of R ² will be described. If z is 0.50 or more, the content of R ^{2 in} the alloy is large, so R ² tends to permeate into the main phase 10 and the intermediate phase 30. From this viewpoint, z is preferably 0.55 or more, more preferably 0.60 or more. On the other hand, when z is 0.80 or less, the melting point of the alloy in the modifier is appropriately lowered, so that the temperature of the heat treatment to be described later becomes appropriate. As a result, the structure of the rare earth magnet precursor can suppress coarsening. From the viewpoint of optimizing the melting point of the alloy, z is preferably 0.75 or less, and more preferably 0.70 or less. As to z, when R ² is two or more kinds of elements, they are the sum of them. The same is true for M ² .

The production method of the reforming material is not particularly limited. Examples of the method for producing the reforming material include a casting method and a liquid quenching method. From the viewpoint that the fluctuation of the alloy component is small and the impurities such as oxides are small depending on the region of the reforming material, the liquid quenching method is preferable.

The amount of penetration of the alloy in the modifier is represented by the formula t (atomic%) of the total composition. The penetration effect of the modifier is confirmed when t is 0.05 atomic% or more, for example, in improvement of magnetic properties and the like. 3, t is preferably 0.1 atomic% or more, more preferably 1.0 atomic% or more, and still more preferably 1.5 atomic% or more, so that the intermediate phase 30 can be clearly recognized . On the other hand, since the modifier contains M ² , if the amount of penetration of the modifier becomes excessive, the magnetization of the rare earth magnet after permeation of the modifier decreases. When t is 10.0 atomic% or less, there is practically no problem in lowering the magnetization. From this viewpoint, t is preferably 9.0 atomic% or less, more preferably 8.0 atomic% or less, and still more preferably 7.0 atomic% or less.

&Lt; Production of a contact body &

The rare earth magnet precursor and the modifier are brought into contact with each other to obtain a contact body. The rare earth magnet precursor is the above-mentioned compact. At this time, at least one surface of the rare earth magnet precursor and at least one surface of the modifier are brought into contact with each other.

<Heat treatment>

The contact body is heat-treated to permeate the melt of the modifier into the inside of the rare earth magnet precursor. Thereby, the melt of the modifying material passes through the intergranular phase of the rare earth magnet precursor and reaches the surface portion of the main phase, and R ² in the modifying material penetrates into the main phase to form a middle phase.

The heat treatment temperature is not particularly limited as long as the modifier is melted and the melt of the modifier can penetrate into the main phase of the rare earth magnet precursor.

As the heat treatment temperature is higher, the melt of the reforming material, particularly R ² , is more likely to penetrate the main phase of the rare earth magnet precursor. From this viewpoint, the heat treatment temperature is preferably 580 DEG C or higher, more preferably 600 DEG C or higher, and still more preferably 620 DEG C or higher. On the other hand, the lower the heat treatment temperature, the easier it is to suppress the texture of the rare earth magnet precursor, particularly the coarsening of the main phase. From this viewpoint, the heat treatment temperature is preferably 800 占 폚 or lower, more preferably 775 占 폚 or lower, and still more preferably 725 占 폚 or lower.

The heat treatment atmosphere is not particularly limited, but an inert gas atmosphere is preferable from the viewpoint of inhibiting the oxidation of the rare earth magnet precursor and the modifier.

[Example]

Hereinafter, the rare-earth magnet of the present disclosure and its manufacturing method will be described more specifically by way of examples. The rare earth magnet of the present disclosure and the method for producing the same are not limited to the conditions used in the following examples.

<Preparation of Samples of Examples 1 to 26>

First, a rare earth magnet precursor is produced. R _{13 . 11} Fe _{80 . 43} Cu _{0 . 10} B _{5 . 99} Ga _{0 .37} was liquid quenched by a single roll method to obtain a thin ribbon. R is shown in Table 1-1 below. As a condition of liquid quenching, the molten metal temperature (discharge temperature) was 1420 deg. C and the roll circumferential speed was 30 m / s. At this time, the cooling rate of the molten metal was 10 ⁶ K / sec. Liquid quenching was carried out in an argon gas reduced-pressure atmosphere. It was confirmed by transmission electron microscopy (TEM) observation that the thin film was nanocrystallized.

The foil was pulverized into a powder, the powder was charged in a die, and the mixture was pressurized and heated to obtain a molded article. The pressurizing and heating conditions were: a pressing force of 400 MPa; a heating temperature of 650 DEG C; and a pressing and heating holding time of 60 seconds.

The formed body was hot-set up (hot-rolled) to obtain a compressed body (plastic-worked body). For hot working, samples with a height of 15 mm were compressed to 4.5 mm. The hot up setting processing conditions were a processing temperature of 780 DEG C, a deformation rate of 0.01 / s, and a reduction rate of 70%. It was confirmed by a scanning electron microscope (SEM) that the compact had nanocrystals oriented. This compact was used as a rare earth magnet precursor.

Nd ₇₀ Cu ₃₀ alloy was prepared as a modifier. Nd powder and Cu powder produced by Kojundo Chemical Co., Ltd. were weighed and arc-melted and liquid quenched to obtain a ribbon.

The rare earth magnet precursor and the reforming material were brought into contact with each other and heat-treated in a heating furnace. The amount of the modifier was 1.59 atomic%, 3.72 atomic% and 5.32 atomic% with respect to the rare earth magnet precursor (see Table 1-1). As the heat treatment conditions, the heat treatment temperature was 625 DEG C and the heat treatment time was 165 minutes.

&Lt; Preparation of Sample of Comparative Example 1 >

The alloy composition for making the rare earth magnet precursor is Nd _{13 . 11} Fe _{80 . 43} Cu _{0 . 10} B _{5 . 99} Ga _{0 .37} , and a sample was prepared in the same manner as in Examples 1 to 26 except that the rare earth magnet precursor was not infiltrated with the modifier.

<Preparation of Samples of Examples 27 to 32>

Samples were prepared in the same manner as in Examples 1 to 26 except that R of the rare earth magnet precursor was the same as in Table 1-3.

<Production of Samples of Examples 33 to 36>

Samples were prepared in the same manner as in Examples 1 to 26 except that the R of the rare earth magnet precursor was the same as that shown in Table 1-3, and the rare earth magnet precursor did not penetrate the reforming material.

&Lt; Preparation of Samples of Examples 37 to 38 >

The alloy composition for producing the rare earth magnet precursor is R _{13 11} Fe _{80 . 80} Cu _{0 . 10} B _{5 .99} and R of the rare earth magnet precursor were the same as in Table 1-3.

&Lt; Example 39 >

A specimen was prepared in the same manner as in Example 6 except that the deformation rate at the time of hot upsetting of the formed article was 0.001 / s.

&Lt; Example 40 >

A specimen was prepared in the same manner as in Example 12 except that the deformation rate at the time of hot upsetting of the formed article was 0.001 / s.

&Lt; Preparation of Sample of Comparative Example 2 >

The alloy composition for making the rare earth magnet precursor is Nd _{13 . 11} Fe _{80 . 43} Cu _{0 . 10} B _{5 . 99} Ga _{0 .37} , respectively.

&Lt; Preparation of Samples of Comparative Examples 3 to 7 >

Samples were prepared in the same manner as in Examples 1 to 26 except that R of the rare earth magnet precursor was the same as in Table 1-3.

&Lt; Preparation of Sample of Comparative Example 8 &

A sample of Comparative Example 8 was prepared similarly to Comparative Example 1 except that R of the rare earth magnet precursor was the same as Tables 1 to 3.

&Lt; Preparation of Sample of Comparative Example 9 &

A sample of Comparative Example 9 was prepared in the same manner as in Comparative Example 2, except that the R of the rare earth magnet precursor was the same as in Tables 1 to 3 and the penetration amount of the modifier was 3.72 at%. Further, the sample of Comparative Example 9 is equivalent to the sample of Comparative Example 8 in which 3.72 atom% of the modifying material is infiltrated.

&Lt; Preparation of Sample of Comparative Example 10 &

A sample of Comparative Example 10 was prepared in the same manner as in Comparative Example 1, except that R of the rare earth magnet precursor was the same as in Tables 1 to 3.

&Lt; Preparation of Sample of Comparative Example 11 >

A sample of Comparative Example 11 was prepared in the same manner as in Comparative Example 2, except that the R of the rare earth magnet precursor was the same as in Tables 1 to 3 and the penetration amount of the modifier was 3.72 at%. The sample of Comparative Example 11 is equivalent to the sample of Comparative Example 10 infiltrated with 3.72 at% of the modifier.

&Lt; Preparation of Sample of Comparative Example 12 >

Samples of Comparative Example 13 were prepared in the same manner as in Comparative Example 2, except that the R of the rare earth magnet precursor was the same as in Tables 1 to 3 and the penetration amount of the modifier was 3.72 at%.

<Evaluation>

Coercive force and residual magnetization of the samples of Examples 1 to 40 and Comparative Examples 1 to 12 were measured. For measurement, a pulse excitation magnetic characteristic measuring apparatus (maximum applied magnetic field: 15T) manufactured by Toei Kogyo Co., Ltd. was used. Both the coercive force and the residual magnetization were measured at 23 캜, 100 캜, 140 캜 and 160 캜.

The results are shown in Tables 1-1 to 1-4 and Tables 2-1 to 2-2. In Tables 1-1 and 1-3, the composition of each sample is listed. As for the coercive force, a gradient DELTA Hc between 23 and 160 DEG C and a gradient DELTA Br between 23 and 160 DEG C for residual magnetization, respectively. Table 2-1 summarizes the condition of the hot upsetting process and the average particle diameter. Here, the average particle diameter means the average particle diameter t of crystal grains composed of the columnar phase 10 and the intermediate phase 30 (see Fig. 3). 4 is a graph showing the relationship between the temperature and the coercive force with respect to the samples of Example 15 and Comparative Example 1. Fig. 5 is a graph showing the relationship between temperature and residual magnetization for the samples of Example 15 and Comparative Example 1. Fig.

Samples of Examples 6, 12, 17, 39 and 40 were observed for texture using a scanning transmission electron microscope (STEM) and subjected to component analysis (EDX ray analysis).

The evaluation results are shown in Figs. 6 to 14 show the evaluation results of the examples and comparative examples shown in Tables 1-1 to 1-4, and Figs. 15 to 26 show the results of evaluation of the examples shown in Tables 2-1 to 2-2 Evaluation result.

6 is a diagram showing a structure observation and a component analysis position of the sample of Example 6. Fig. 7 is a diagram showing the results of a structural observation and a component analysis of a sample (first field of view) of Example 6. Fig. Fig. 8 is a diagram showing the results of the structural observation and the component analysis of the sample (second field of view) of Example 6. Fig. Fig. 9 is a diagram showing a structure observation and a component analysis position for the sample of Example 12. Fig. 10 is a diagram showing the results of a structural observation and a component analysis of a sample (first field of view) of Example 12. Fig. 11 is a diagram showing a result of a structural observation and a component analysis of a sample (second field of view) of Example 12. Fig. 12 is a diagram showing a structure observation and a component analysis position of the sample of Example 17. Fig. 13 is a diagram showing a result of a structural observation and a component analysis of a sample (first field of view) of Example 17. Fig. 14 is a diagram showing a result of a structural observation and a component analysis of the sample (second visual field) of Example 17. Fig.

15 is a view showing an example of a particle diameter t of a crystal grain with respect to the sample of Example 39. Fig. 16 is a view showing an example of a grain size t of crystal grains for the sample of Example 40. Fig. 17 is a diagram showing an example of a grain size t of a crystal grain with respect to the sample of Example 6. Fig. 18 is a diagram showing an example of a particle diameter t of a crystal grain with respect to the sample of Example 12. Fig. The average grain size in Table 2 is an average grain size t of each grain contained in the field of view in each of Figs. 15 to 18.

19 is a diagram showing a result of a tissue observation and a component analysis position for the sample of Example 39. Fig. 20 is a diagram showing the result of the component analysis at the position indicated by the white line in Fig. Fig. 21 is a diagram showing a result of a tissue observation and a component analysis position for the sample of Example 40. Fig. 22 is a diagram showing the result of the component analysis at the position indicated by the white line in FIG. 23 is a diagram showing a result of a tissue observation and a component analysis position for the sample of Example 6. Fig. Fig. 24 is a diagram showing the result of the component analysis at the position indicated by the white line in Fig. 23. Fig. Fig. 25 is a diagram showing a result of a tissue observation and a component analysis position for the sample of Example 12. Fig. 26 is a diagram showing the result of the component analysis at the position indicated by the white line in Fig. 20, 22, 24, and 26, the peak concentrations of La and Ce in the grain boundary phase and the peak concentrations of them in the grain boundary phase are shown in Table 3 with respect to Example 39, Example 40, The total peak concentration is obtained.

[Table 1-1]

[Table 1-2]

[Table 1-3]

[Table 1-4]

It can be seen from Tables 1-1 to 1-4 that the absolute values of DELTA Hc are smaller than those of Comparative Examples 1 to 4 for all the samples of Examples 1 to 38. Further, it was confirmed that the absolute value of DELTA Br was very small for all the samples of Examples 1 to 38. [ It was also confirmed that, in Comparative Examples 5 to 7, the decrease in magnetization at high temperature was large. From these results, it was confirmed that the rare-earth magnet of the present disclosure does not greatly affect the magnetization and can suppress the lowering of the coercive force at high temperature. The same can be confirmed in Figs. 4 and 5. 6 to 11, formation of the intermediate phase 30 can be confirmed.

Samples of Examples 1 to 32 and Examples 37 to 38 and Samples of Comparative Examples 9, 11 and 12 are compared with respect to the sample having permeated the modifier. With respect to the rare earth elements, in the samples of Examples 1 to 32 and 37 to 38 containing Nd, Ce and La, in the samples of Comparative Examples 9, 11 and 12 containing only Nd and La , It was confirmed that the absolute value of DELTA Hc was smaller. It was confirmed that the samples which did not permeate the modifier were the same between the samples of Examples 33 to 36 and the samples of Comparative Examples 8 and 10.

[Table 2-1]

[Table 2-2]

[Table 3]

From Table 2, it was confirmed that even when the strain rate is slow, the increase of the average grain size of the crystal grains is suppressed, and as a result, the coercive force is not deteriorated. In addition, it was confirmed that magnetization was improved when the strain rate was low. It can be seen from Table 3 that the concentration of Ce and La, particularly La, of the intergranular phase 20 is high and the maintenance of coercive force and the improvement of magnetization are suppressed when the strain rate is low, 10) to the grain boundary phase (20).

From the above results, the effect of the rare earth magnet of the present disclosure and the manufacturing method thereof can be confirmed.

10 columns
20 in-process
30 median
100 Rare earth magnet (precursor)

Claims (11)

However,
The grain boundary phase existing around the main phase
Respectively,
The total composition is represented by the formula (Nd _x (Ce, La) _(1-xy) R ¹ _y ) _p Fe _(100-pqrs) Co _q B _r M ¹ _s (R ² _z R ³ _w M ² _{1 -zw} ) _t (where, R ¹ is at least one element selected from rare earth elements other than Nd, Ce, and La, R ² is at least one member selected from Pr, Nd, Pm, Sm, Eu and Gd, R ³ is R ² M ¹ is at least one element selected from Ga, Al, Cu, Au, Ag, Zn, In and Mn, and an inevitable impurity element, M ² is at least one element selected from the group consisting of R ² and by alloying with R ^3, R ² and R ³ _{z w} M alloying elements and inevitable impurity elements to the melting point of the ² _{1 -zw} lower than the melting point of the R ^2, also
p, q, r, s and t are atomic%
5.0? P? 20.0,
0? Q? 8.0,
4.0? R? 6.5,
0? S? 2.0 and
0? T? 10.0
ego,
x, y, z and w have a molar ratio
0.4? X? 0.8,
0? Y? 0.1,
0.5? Z? 0.8 and
0? W?
), And is also represented by
Wherein said La is contained at a molar ratio of 1/9 to 3 times,
Rare earth magnets. The rare-earth magnet according to claim 1, wherein La is contained at a molar ratio of 1/9 to 2 times with respect to Ce. 3. The magnetic recording medium according to claim 1 or 2, further comprising an intermediate phase between the main phase and the grain boundary phase,
Wherein t is 0.1? T? 10.0, and
Wherein the concentration of R ² is higher in the intermediate phase than in the main phase,
Rare earth magnets. The rare-earth magnet according to any one of claims 1 to 3, wherein R ² is Nd. The rare-earth magnet according to claim 3 or 4, wherein the concentration of R ² is 1.5 to 8.0 times higher in the main phase than in the intermediate phase. The rare-earth magnet according to any one of claims 3 to 5, wherein the intermediate phase has a thickness of 2 to 100 nm. Equation _{(Nd x (Ce, La)} (1-xy) R 1 y) p Fe (100-pqrs) Co q B r M 1 s ( single, R ¹ is selected from rare earth elements other than Nd, Ce, and La M ¹ is at least ^{one element selected} from Ga, Al, Cu, Au, Ag, Zn, In and Mn, and an inevitable impurity element, and
p, q, r and s are atomic%
5.0? P? 20.0,
0? Q? 8.0,
4.0? R? 6.5 and
0? S? 2.0
ego,
When x and y are in a molar ratio
0.4? X? 0.8 and
0? Y? 0.1
), And preparing a molten metal containing La in a molar ratio of 1/9 to 3 times with respect to Ce,
Quenching the molten metal to obtain a thin ribbon,
Compressing the plurality of the thin ribbons in a hot state to obtain a molded article, and
And compressing the molded body in hot state to obtain a compressed body
Including,
A method of manufacturing a rare earth magnet. The method according to claim 7, wherein said molten metal contains said La in a molar ratio of 1/9 to 2 times that of said Ce. The method of claim 7 or claim 8 wherein the formula ^{_{R 2 z R 3 w M 2}} 1 -zw ( However, R ² is at least one member selected from Pr, Nd, Pm, Sm, Eu and Gd, R ³ is and at least one element selected from rare earth elements other than R ^2, the alloy element which M ² is lower than the melting point of the R ² and R ³ by the alloying, R ² R ³ _{z w} ² M ₁ R ² and a melting point of _-zw Wherein z and w are molar ratios of 0.5? Z? 0.8 and 0? W? 0.1, which is an inevitable impurity element,
Contacting the compression body and the modifying material to each other to obtain a contact body, and
And the contact body is heat-treated to penetrate the melt of the modifying material into the inside of the compression body
Including,
Way. 10. The method of claim 9, wherein R &lt; ^{2 &gt;} is Nd. 11. The method according to any one of claims 7 to 10, wherein the compact is compressed at a strain rate of less than 0.01 / s to less than 0.01 / s, a reduction rate of 50 to 70%, and a temperature of 700 to 800 캜, &Lt; / RTI &gt;

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