JP3468648B2 - Amorphous hard magnetic alloy and amorphous magnetic alloy casting - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an amorphous hard magnetic alloy that can be manufactured by a casting method and exhibits a high coercive force, an amorphous hard magnetic alloy cast material, and a method for manufacturing an amorphous hard magnetic alloy cast material.

[0002]

2. Description of the Related Art Conventionally, to find a metal-based amorphous alloy composition which can be manufactured with a small cooling rate like oxide glass and can obtain a large thickness,
It was one of the major research subjects in the field of material technology. Against this background, many amorphous alloys have been produced by the liquid quenching method until now. However, many of these conventional amorphous alloys have critical cooling conditions of 10 ⁴ K / s or more for forming an amorphous phase. And
The thickness of the obtained amorphous alloy was usually a ribbon or a fine wire having a thickness of 0.2 mm or less, or a powder having a particle diameter of 50 μm or less.

[0003]

However, in 1989, an amorphous bulk alloy having a thickness of about 7 mm was first manufactured by a casting method in a La-Al-Cu system material. Then, thereafter, the amorphous bulk alloys of this type are La-Al-TM based, Mg-La-TM based, Z
r-Al-TM system, Ti-Zr-Al-TM-Be system, Ti-
It has been proved that Zr-TM-Be system (where Ln is a rare earth metal and TM is a transition metal) can be manufactured. Many of these amorphous alloys
It has a critical cooling rate of 10 ² K / s or less, can be manufactured by a normal casting method in a copper mold, and the results of alloy research based on these component systems show that the critical cooling rate is about 1.
An amorphous bulk alloy having a diameter of 10 mm or more has been discovered, which is extremely small at about 5 K / s, can be manufactured by an arc melting method or a water quenching method.

Based on the above alloy research, the present inventors have recently begun to develop an amorphous bulk alloy containing Fe, and the first additive element such as Al or Ga to Fe and P, C, As a result of continuing the research on the alloy of the component system to which the second additive element such as B and Ge is added, it is a bulk amorphous alloy (metallic glass), which can be manufactured by the casting method, and has a hard magnetic property. The alloy was discovered and the present invention was reached.

The present invention has been made in view of the above circumstances, and can be produced by a casting method having a low cooling rate, rather than a production method having a high cooling rate such as a liquid quenching method, and is obtained by an ordinary liquid quenching method. It is an object of the present invention to provide an amorphous hard magnetic alloy having an unprecedented thickness and exhibiting hard magnetism, an amorphous hard magnetic alloy cast material, and a method for producing an amorphous hard magnetic alloy cast material.

[0006]

In order to solve the above-mentioned problems, the present invention has the following composition. _{A x - (Fe 1-a} Co a) y - Ga z where A, Nd, Sm, Pr, represents at least one element selected from among Pm, x indicating the composition ratio,
y and z are in atomic%, 50 ≦ x ≦ 75, 10 ≦ y ≦ 45, 5 ≦
It is assumed that the relationship of z ≦ 15 is satisfied, and that a is 0 ≦ a ≦ 0.5. In the above structure, it is preferable that y representing the composition ratio is in the range of 25 ≦ y ≦ 35 in atomic%.
Further, in the above structure, it is preferable that ferromagnetic clusters having disordered anisotropy are generated.

Further, the amorphous alloy cast material according to the present invention is made of the amorphous alloy according to each of the above-mentioned constitutions in order to solve the above problems.

[0008]

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. The amorphous hard magnetic alloy according to the present invention contains a rare earth metal such as Sm, Pr, or Pm as a main component, to which a predetermined amount of Fe is added, and further, Ga a
It is realized by the component system to which is added. The amorphous hard magnetic alloy according to the present embodiment has the general formula A _x −
_{(Fe 1-a Co a)} y - can be expressed by Ga _z, in the general formula formula, A is, Nd, Sm, Pr,
Represents at least one element selected from among Pm, x indicating the set composition ratio, y, z is in atomic%, 50 ≦ x ≦ 7
It is preferable that the relationship of 5, 10 ≦ y ≦ 45, 5 ≦ z ≦ 15 is satisfied, and a satisfies the relationship of 0 ≦ a ≦ 0.5. Also,
In the above composition range, the composition ratio y is more preferably in the range of 25 ≦ y ≦ 35.

"Reasons for limiting composition" In the composition system of the present invention,
In order to obtain an amorphous phase even when manufactured by a casting method, basically, the content of Fe should be in the range of 0 to 90 at% and the content of element D should be in the range of 0 to 93 at%. Good. However, the cooling rate of the molten metal obtained by the usual casting method has a certain limit depending on the diameter of the casting material, and the cooling rate becomes slower as the diameter of the casting material increases.

When the composition system of the present invention is used, an amorphous phase can be obtained even if the composition is cooled at a cooling rate (several K to several tens of K / s) which is significantly slower than the cooling rate realized by the conventional liquid quenching method. However, even so, in order to reliably generate the amorphous phase in the range of about 1 to 10 mm in diameter which is practical as a bulk material, the Fe content is preferably set to the range of 10 to 45 atom%. When Fe is contained in excess of this range, the production rate of the crystal phase becomes high or the crystal phase becomes the main component, which is not preferable. In addition, F within the above range
Since the maximum magnetic energy product tends to reach a peak as described below even when the Fe content is around 30 atomic% of the Fe content, the Fe content is preferably in the range of 20 to 40 atomic%. Furthermore, the range of 25 to 35 atomic% is more preferable.

Further, in the composition system according to the present invention, F
Part of e may be replaced with Co. In the case of a crystalline alloy, Co has a large magnetocrystalline anisotropy, has an effect of improving hard magnetism, and increasing saturation magnetization, but similar effects can be obtained in the case of the alloy of the present invention having a ferromagnetic cluster. It can be expected to be obtained. In the present invention, Fe of 50
If the content is up to%, good hard magnetism can be obtained even if Co is replaced, and if it exceeds 50%, the hard magnetism deteriorates. Therefore,
When substituting Fe for Co, it is preferably 50% or less of Fe. Further, it is more preferable to set it to 25% or less. The element A is an element necessary for exerting hard magnetism, and it is preferable to add at least 50 atomic% or more, but if it is added in a large amount, it becomes difficult to form an amorphous material. Is preferred. The element D is an element necessary for forming the metallic glass, and it is preferable to add at least 5 atomic% or more, and if added in excess of 15 atomic%, the hard magnetism deteriorates.
The following is preferable.

In order to produce the amorphous hard magnetic alloy of the above composition system, for example, elemental elemental powders of the respective components are prepared, these elemental elemental powders are mixed so as to fall within the above composition range, and then this mixed powder is prepared. Is melted by a melting device such as a crucible in an inert gas atmosphere such as Ar gas to obtain a molten alloy having a predetermined composition. Next, this molten alloy is cooled by a casting method, cast into a mold, and taken out from the mold to obtain a bulk amorphous hard magnetic alloy cast material having a predetermined size.

FIG. 1 is a diagram showing an example of a casting apparatus used in the manufacturing method of this example. High frequency coil for heating 1
The molten alloy 3 of the composition system is housed inside a cylindrical crucible 2 around which is placed, and a mold 4 such as a copper mold is arranged on the lower side of the crucible 2. An injection hole 2a is formed at the lower end of the crucible 2, and a cylindrical casting space 5 is formed inside the mold 4. Also,
Although not shown in the drawing, an inert gas supply device is connected to the upper part of the crucible 2 so that the inside of the crucible 2 can be maintained in an inert gas atmosphere, and the internal pressure of the crucible 2 can be increased if necessary. The molten alloy can be injected into the casting space 5 of the mold 4 from the injection hole 2a of the crucible 2.

To obtain an amorphous hard magnetic alloy cast material using the apparatus shown in FIG. 1, the crucible 2 as shown in FIG.
It is obtained by injecting a molten alloy into the casting cavity 5 of the mold 4 through the injection hole 2a of the crucible 2 by applying a predetermined pressure P with an inert gas to the inside of the vessel, and then cooling the molten alloy in the casting cavity 5. be able to. The amorphous hard magnetic alloy casting material produced as described above is mainly composed of an amorphous phase,
It becomes a hard magnetic casting material having a high coercive force.

In the above example, the casting apparatus provided with the crucible 2 and the mold 5 has been described, but it goes without saying that the shapes of the crucible 2 and the mold 5 are not particularly limited. Therefore, as the crucible and the mold, for example, as shown in FIG. 3, a casting apparatus including a crucible type melting device 8 including a cylinder 6 and a piston 7 is used, and the piston 7 is pulled downward to melt the molten metal in the cylinder 6. It goes without saying that a device for pulling in and cooling 3 may be used, and of course, various structures widely used as a casting device may be applied. In addition to this, it is needless to say that a widely used continuous casting device or the like may be used. Again,
Since the alloy according to the present invention only needs to have an amorphous phase as a main component, it goes without saying that even if a part of the alloy is crystallized by heat treatment after casting, it is within the scope of the present invention. Further, even by the liquid quenching method which has been conventionally used, it is sufficiently possible to obtain a hard magnetic alloy exhibiting hard magnetism by changing the cooling conditions and the thickness of the ribbon.

[0017]

EXAMPLE A powder of Nd, Fe, and Al is used as N powder.
d _90-x Fe _x Al were mixed in various proportions such that ₁₀ having a composition, the mixed powder was dissolved in a crucible of a casting apparatus of the configuration shown in FIG. 1, which several having a cylindrical cast crowded space The pin-shaped sample was obtained by performing the injection casting method of casting into the copper mold. The shape of the obtained sample is 50 mm in length and 1 to 1 in diameter.
It was 0 mm. The injection pressure applied to the crucible was 0.
It was fixed at 05 MPa. Further, for comparison, a molten metal having the same composition was used, and a cross-sectional area of 0.04 × 1 m was obtained by a quenching method by a known one-roll method in an Ar gas atmosphere.
A m ² ribbon having a thickness of 0.04 mm and a width of 1 mm was manufactured as a comparative sample.

The obtained samples were observed with a transmission electron microscope (TEM), a scanning electron microscope (SEM) and an optical microscope (OM). The sample observed with an optical microscope was etched at room temperature with a 0.5 vol% hydrofluoric acid solution. For each sample, energy dispersive X
The respective characteristics were measured by a line spectroscopy (EDX), a differential scanning calorimetry (DSC), and a vibrating sample magnetometer (VSM).

FIG. 4 is a Nd-Fe-Al system triangular composition diagram showing an amorphous phase generation region. In FIG. 4, a circle indicates a composition region where an amorphous phase is obtained, a ● indicates a composition region where a crystalline phase is obtained, and a semi-black circle indicates a mixed region of a crystalline phase and an amorphous phase. 0-9
It has been found that an amorphous phase can be obtained in a wide composition region of 0 atomic% and in a wide composition region of 0 to 93 atomic% with an Al content.

FIG. 5 shows an X-ray of a cylindrical sample having a composition of Nd ₇₀ Fe ₂₀ Al ₁₀ and having a diameter of 3 mm, 5 mm, and 7 mm and a liquid quench ribbon sample having a cross-sectional area of 0.04 × 1 mm ² produced by the single roll method. A diffraction pattern is shown. From FIG. 5, no peculiar peak was observed in any of the samples, and a broad curve peculiar to the amorphous phase was obtained, confirming that these samples are mainly composed of the amorphous phase.

Further, in the obtained sample, Nd ₇₀ Fe ₂₀
A sample having a composition of Al ₁₀ and a diameter of 3 mm and Nd ₆₀ Fe ₃₀ A
When microscopically observing the structure of a sample having a composition of l ₁₀ and a diameter of 3 mm, a sample having a composition of Nd ₇₀ Fe ₂₀ Al ₁₀ has a substantially uniform solid structure, and a sample having a composition of Nd ₆₀ Fe ₃₀ Al _{10 has} a composition of Partly within the same plain fabric 0.1-
Needle-like tissue formation of about 4 μm was observed. Therefore, FIG. 6 shows the result of analysis by the energy dispersive X-ray spectroscopy (EDX) for each of the needle-shaped tissue portion and the tissues of the other plain portions.

FIG. 6 (A) shows the analysis result of the non-needle-shaped tissue portion which is not a solid portion, and FIG. 6 (B) shows the analysis result of the needle-shaped tissue portion. No difference was seen. Therefore, both the portion where the needle-like structure is exposed and the uncoated portion are amorphous phase regions, but the portion where the needle-like structure is exposed has a disordered anisotropy developed from the disordered packing structure. It is estimated that

Here, the disordered packing structure is a structure proposed by the inventors of the present invention that is proposed by using an amorphous alloy material having a small critical cooling rate.
TM series, Mg-La-TM series, Zr-Al-TM series, Ti-
In the system represented by Zr-Al-TM-Be system, Ti-Zr-TM-Be system (however, Ln is a rare earth metal and TM is a transition metal), etc., the element that constitutes the ternary system The atomic diameters of 10 to 12% differ from each other,
Moreover, the three constituent elements are composed of elements having a large, medium, and small atomic diameter relationship. A liquid composed of elements having such an atomic diameter has a high packing density of atoms, and is expected to have a so-called highly disordered liquid structure.

That is, it is known that in an amorphous alloy having a high degree of disordered packing, the solid / liquid interface energy is increased and the nucleation of crystals from the liquid is greatly suppressed, so that crystallization is prevented and the amorphous state is formed. Can be explained as doing. The disordered anisotropy means Ni-Fe and Ni-F.
The atomic arrangement between e-Al is disordered in the long range, but has order in the short range, and as a result, magnetic anisotropy due to the short range order appears. Therefore, it is considered that the alloy according to the present invention exhibits hard magnetism as described later.

[0025] Figure 7, Nd _90-x Fe _x Al at ₁₀ having a composition system, a plurality of copper plurality of molten metal formed by setting each composition ratio x in 10, 20, 30, 40 atomic% By casting in a mold, diameters 1, 2, 3,
Pin-shaped samples of 4, 5, 6, 7, 10 mm and length of 50 mm are prepared, and the results of specifying the tissue state in these samples are shown. From the results shown in FIG. 7, in the injection casting method using the copper mold, the maximum diameter was 7 when the Fe content was 20 atomic%.
It has been found that even an amorphous alloy sample having a diameter of 1 mm can be manufactured, and an amorphous alloy sample having a diameter of 1 mm can be manufactured in a wide range of 10 to 50 atom%. In addition, it was found that a sample having a mixed phase of a crystalline phase and an amorphous phase can be prepared up to a sample having a diameter of 10 mm when Fe is 20 atomic%.

FIG. 8 shows a pin-shaped diameter of 1 mm,
A sample having a composition of Nd ₈₀ Fe ₁₀ Al ₁₀ and Nd ₇₀ Fe ₂₀ A
a sample having a composition of l _10, a sample having a composition of Nd ₆₀ Fe ₃₀ Al _10, a sample having a composition of Nd ₅₀ Fe ₄₀ Al ₁₀ , and a sample having Nd ₄₀
2 shows the measurement results when differential scanning calorimetry (DSC) was performed on a sample having a composition of Fe ₅₀ Al ₁₀ . As seen from the DSC curve in FIG. 8, exothermic peaks due to crystallization are obtained in the alloys of all compositions. The exothermic peak of each sample was in the range of about 480 to 550 ° C. Further, in the DSC curves of these examples, a gradual exothermic phenomenon is observed in a temperature region slightly lower than the temperature at which the exothermic peak occurs, and this exothermic phenomenon will be described later.

FIG. 9 shows the DSC curve of each pin-shaped sample when the composition is Nd ₆₀ Fe ₃₀ Al ₁₀ and the diameter is set to 1, 2, and 3 mm, respectively. Also in FIG. 9, a DSC curve similar to the DSC curve shown in FIG. 8 was obtained. Note that crystallization was observed in the sample having a composition of Nd ₆₀ Fe ₃₀ Al ₁₀ whose measurement results are shown in FIG. 9 by heating at 600 ° C. for 10 minutes and then gradually cooling. As a result of analysis and identification of the precipitates, it was confirmed that hexagonal close-packed Nd, equiaxed Al ₂ Nd, and tetragonal δ (Nd ₃ Fe _1-x Al _x ) phases were precipitated. .

Next, FIG. 10 shows a diameter of 5 m produced by an injection casting method in which the same copper mold as above is cast under the same conditions as above.
m, 50 mm long Nd ₅₅ Fe ₃₅ Al ₁₀ composition sample, 3 mm diameter, 50 mm long Nd ₆₀ Fe ₃₀ Al ₁₀ composition sample, 5 mm diameter, 50 mm long Nd ₇₀ F
9 shows the result of obtaining a magnetization curve (JH curve) in a sample having a composition of e ₂₀ Al ₁₀ . It was revealed that all the samples showed magnetic hysteresis showing high coercive force, and it was proved that they were hard magnetic alloys.

FIG. 11 shows the effect on the magnetic characteristics when the Fe content is adjusted in the sample of the composition system Nd _{90 -x} Fe _x Al ₁₀ . FIG. 11 (A)
Shows the relationship between remanent magnetization and Fe content, FIG. 11 (B) shows the relationship between coercive force and Fe content, and FIG. 11 (C) shows the maximum magnetic energy product ((BH) _max ) and Fe content. FIG. 11D shows the relationship between the magnetization and the Fe content. From these results shown in FIG. 11, the Fe content was 1
20-40 atom% even within the range of 0-45 atom%
It is found that the range of 25 to 35 atomic% is more preferable in order to obtain a good maximum magnetic energy product.

FIG. 12 shows a sample made of Nd ₇₀ Fe ₂₀ Al ₁₀ having a diameter of 1, 3, 5 mm and a ribbon sample having the same composition produced by a liquid quenching method using a one-roll method. The result of having obtained the magnetization curve is shown. Book
The sample according to the embodiment exhibits magnetic hysteresis regardless of the diameter, and it is clear that the sample is a hard magnetic material, whereas the ribbon sample obtained by the quenching method does not exhibit magnetic hysteresis and is almost paramagnetic. An equivalent curve was shown.

FIG. 13 shows the magnetization curves of ribbon samples prepared by the liquid quenching method with various composition systems, and Nd _90-x F
In the sample of the composition system e _x Al ₁₀ , the composition ratio x is set to 2
The hard magnetic material was not obtained in any proportion of 0, 30, 40, 50, 60 and 70. Therefore, it was found that the ribbon obtained by the liquid quenching method does not exhibit hard magnetism.

FIG. 14 shows the relationship between the remanent magnetization and coercive force of a sample according to the present invention having a composition of Nd ₆₀ Fe ₃₀ Al ₁₀ and a diameter of 3 mm and the annealing temperature, and the remanent magnetization and coercive force of a ribbon sample of the same composition and the annealing. It shows the relationship of temperature. In addition, in FIG. 14, as-cast represents a sample as cast. From the results shown in FIG. 14, it is clear that the sample according to the present embodiment is a hard magnetic material.
In addition, when annealing is performed at 327 ° C. (600 K) for 10 minutes, the amorphous phase is considered to have transitioned to the crystalline phase, and in this case, a mixed state of Nd, Al ₂ Nd, and δ phase is obtained. It seems that the residual magnetization is 0.045.
T, the coercive force decreased to 265 kA / m.

FIG. 15 shows a sample having a composition of Nd ₇₀ Fe ₂₀ Al ₁₀ and a diameter of 5 mm, which is manufactured as 1432.
It shows the relationship between the residual magnetization and the temperature when heating and cooling after applying a magnetic field of kA / m. This sample has ferromagnetism with a Curie temperature at about 327 ° C (600K), and its remanent magnetization and coercive force are 0.122 for cast materials, respectively.
T, 277 kA / m, 1 at 327 ° C (600K)
Remaining magnetization of 0.128 when annealed for 0 minutes
T, coercive force was 277 kA / m.

FIG. 16 shows a sample having a composition of Nd ₇₀ Fe ₂₀ Al ₁₀ and a sample having a composition of Nd ₆₀ Fe ₃₀ Al ₁₀ .
The DSC curve measured at 0.33 K / s is shown. From this figure, the melting point Tm of the sample having the composition Nd ₇₀ Fe ₂₀ Al ₁₀ is 590 ° C. (863 K), and the crystallization start temperature is 505 ° C. (7
78K), the melting point T of the sample having the composition of Nd ₆₀ Fe ₃₀ Al ₁₀
It was found that m was 648 ° C and the crystallization temperature was 511 ° C.

As shown by the measurement results of the DSC curves shown in FIGS. 16 and 9, in the alloy of the system according to the present embodiment , the glass transition and the supercooled body region do not exist in the temperature range before crystallization. On the other hand, the ZrAlNi system or the ZrAl system having a small critical cooling rate previously studied by the present inventors.
In the case of a Cu-based or other component-based amorphous alloy, as shown in FIG. 17, a supercooled liquid region and a glass transition temperature T which are in an internal equilibrium state in a temperature region lower than the crystallization start temperature T _x.
g was present. The alloy of the system according to the present embodiment and FIG.
Since the alloys of the system shown in 7 are very different in this respect,
Amorphous forming ability of the alloy system according to this embodiment appears to be based on different factors than the alloy system to which the present inventors have earlier studied.

First, in the alloy of the system according to the present embodiment, the conversion ratio T _x / T _m between the crystallization start temperature (T _x ) and the melting point (T _m ) is as high as 0.9, and the crystallization is performed. The temperature interval between the starting temperature (T _x ) and the melting point (T _m ) is as small as 85 ° C. Book
Large amorphous forming ability in an alloy system according to the embodiment is believed this extremely high conversion ratio _T x / _{T m,} and those due to small _{ΔT m (= T x -T m} ).
As shown in FIGS. 10 to 11, Nd ₇₀ Fe ₂₀ Al
The sample having the composition of ₁₀ exhibits ferromagnetism having a Curie temperature at about 327 ° C. (about 600 K), and the residual magnetization and the coercive force of the cast material are 277 kA / m, respectively. In addition, this implementation
It is presumed that the hard magnetism in the alloy of the system according to the above form is due to the homogeneous development of ferromagnetic clusters having a large disorder anisotropy.

Next, FIG. 18 shows the results of obtaining the magnetization curves of NdFeGa-based samples in which Ga was added in place of NdFeAl-based Al. Samples of the composition Nd ₆₀ Fe ₃₀ Ga ₁₀ and Nd ₇₀ Fe It was found that any of the samples having a composition of ₂₀ Ga ₁₀ exhibited magnetic hysteresis and had hard magnetism. FIG. 19 shows a magnetization curve of a sample in which a part of Fe is replaced with Co in the NdFeAl system.
In this example, in the sample of the composition system represented by the formula Nd ₇₀ Fe _20-X Co _X Al ₁₀ (sample diameter 30 mm), Fe
Shows the magnetization curve of the sample in which X indicating atomic% of X is set to 0, 5 and 10 and 15, respectively, and X is 5, that is, the substitution amount is 2
Good hard magnetism was exhibited up to 5%.

FIG. 20 shows that in a sample of the composition system represented by the formula Nd ₆₀ Fe _30-X Co _X Al ₁₀ (sample diameter 50 mm), X representing 0 atomic% of Fe was 0, 5, 10, 15, and 3.
The magnetization curve of the sample set to 0 is shown, but X is 1
Good hard magnetism is obtained up to 5 atom%, that is, up to a substitution amount of 50%. From the results shown in FIGS. 19 and 20 above, N
50% of Fe in d ₆₀ Fe _30-X Co _X Al ₁₀ system
It was clear that Co could be replaced by Co, and it was also found that when 25% of Fe was replaced, more preferable hard magnetism was exhibited.

FIG. 21 shows Nd-F showing the amorphous phase formation possible region in the sample immediately after being quenched by the single roll method.
It is a triangular composition diagram of e-Ga system. In FIG. 21, a circle indicates a composition region in which an amorphous phase is obtained, a ● indicates a composition region in which a crystalline phase is obtained, and a semi-black circle indicates a mixed region of a crystalline phase and an amorphous phase. At 0
It has been found that an amorphous phase can be obtained in a wide composition range of 90 atomic% and in a wide composition range of 0 to 45 atomic% with a Ga content.

FIG. 22 is an Nd-Fe-Ga system triangular composition diagram showing an amorphous phase producible region in the case where a pin-shaped sample having a diameter of 1 mm is produced by the casting method using the above-mentioned copper casting apparatus. In FIG. 22, a circle indicates a composition region in which an amorphous phase is obtained, a circle indicates a composition region in which a crystalline phase is obtained, and a semi-black circle indicates a mixed region of a crystalline phase and an amorphous phase. It was found that an amorphous phase can be obtained in the composition region of 5 to 65 atom% and in the composition region of Ga content of 2.5 to 25 atom%.

In FIG. 23, each pin-shaped diameter is 1 m.
m, a sample having a composition of Nd ₄₅ Fe ₅₀ Ga ₅ and Nd ₅₀ Fe
₄₅ and the sample of Ga ₅ having a composition, for samples of Nd ₅₀ Fe ₄₀ Ga ₁₀ having a composition, shows the measurement results when subjected to differential scanning calorimetry (DSC). As seen from the DSC curve in FIG. 23, an exothermic peak due to crystallization is obtained in the samples having any composition. The exothermic peak of each sample is about 480
It was in the range of 530 ° C.

FIG. 24 shows a DSC curve measured at 0.33 K / s for a sample having a composition of Nd ₅₀ Fe ₄₀ Ga ₁₀ . From this figure, it was found that the melting point Tm of the sample having the composition Nd ₅₀ Fe ₄₀ Ga ₁₀ was 584 ° C. (311 K) and the crystallization start temperature was 517 ° C. (244 K).

FIG. 25 shows a sample having a composition of Nd ₇₀ Fe ₂₀ Ga _10, a sample having a composition of Nd ₆₀ Fe ₃₀ Ga ₁₀ and Nd ₅₀ Fe _40.
For each of the samples having the composition Ga _10, the magnetization curves of the as-cast sample (diameter mm) are shown. As shown in FIG. 25, it is clear that the samples of any composition have a high coercive force, and it is clear that they are hard magnetic materials.

FIG. 26 shows the remanent magnetization of each sample when cast by the above-mentioned casting device in each sample composition of Nd-Fe-Ga system, and FIG. 27 shows the retention of each sample composition of Nd-Fe-Ga system. Fig. 28 shows the magnetic force, and Fig. 28 shows the maximum magnetic energy product ((BH) in each sample composition of Nd-Fe-Ga system.
_max ) is shown. From these results shown in FIGS. 26 to 28, in the Nd-Fe-Ga system, 50 ≦ Nd ≦ 75, 1
It is apparent that excellent hard magnetism can be obtained within the range of the present invention of 0 ≦ Fe ≦ 45 and 5 ≦ Ga ≦ 15. Further, among the above compositions, 50 ≦ Nd ≦ 70, 15
It can be seen that the range of ≦ Fe ≦ 45 and 5 ≦ Ga ≦ 15 is more preferable.

[0045]

Amorphous hard magnetic alloy of the present invention as described above, according to the present invention is _{A x - (Fe 1-a} Co a) y - Ga z
Having a composition comprising, A is indicated Nd, Sm, Pr, and one or more elements of Pm, x indicating the set composition ratio, y, z is 5 atomic%
Since 0 ≦ x ≦ 75, 10 ≦ y ≦ 45, 5 ≦ z ≦ 15 are satisfied, and a satisfies 0 ≦ a ≦ 0.5, the critical cooling rate is small and the casting method The feature is that it can be easily made amorphous. Further, the alloys of this system have hard magnetism, and exhibit high coercive force and excellent maximum magnetic energy product. Furthermore, the Fe content in atomic% is 25 ≦ y ≦
Within the range of 35, it is possible to provide an amorphous hard magnetic alloy having a particularly excellent maximum magnetic energy product. Therefore, according to the present invention, it is possible to obtain a hard magnetic alloy and a hard magnetic alloy cast material which can be easily made amorphous and exhibit hard magnetism.

Next, a molten alloy having the above composition is cast into a mold to easily obtain a magnetic alloy casting material mainly composed of an amorphous phase and exhibiting hard magnetism. In addition, it is possible to obtain a cast material with a desired shape by changing the shape of the mold during casting, so it is easy to obtain a cast material with a desired shape, for example, a thickness of several mm, and with hard magnetic properties. Can be obtained. Even with the conventional liquid quenching method, it is sufficiently possible to obtain a hard magnetic alloy exhibiting hard magnetism by changing cooling conditions and ribbon thickness.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a casting apparatus for producing a hard magnetic alloy cast material of a system according to the present invention.

FIG. 2 is a view showing a state in which a hard magnetic alloy casting material of the system according to the present invention is cast into a mold to be manufactured.

FIG. 3 is a diagram showing another example of a casting apparatus used for producing a hard magnetic alloy cast material of the system according to the present invention.

FIG. 4 is an Nd-F showing a region where an amorphous phase can be generated.
It is a triangular composition diagram of e-Al system.

FIG. 5 is a composition of Nd ₇₀ Fe ₂₀ Al ₁₀ and has a diameter of 3
3 is a diagram showing an X-ray diffraction pattern of a cylindrical sample having a size of 5 mm, 5 mm, and 7 mm and a liquid-quenched ribbon sample having a cross-sectional area of 0.04 × 1 mm ² manufactured by the one-roll method.

FIG. 6 shows the results of analysis by energy dispersive X-ray spectroscopy (EDX). FIG. 6 (A) shows the result of analysis of a plain part that is not a needle-shaped tissue part, and FIG. 6 (B) shows a needle. It is a figure which shows the analysis result of the textured tissue part.

FIG. 7 is a diagram showing the results of specifying the texture state of the sample obtained when pin-shaped samples were prepared by changing the composition ratio x and the diameter in the composition system of Nd _90-x Fe _x Al ₁₀ .

FIG. 8 is a diagram showing a measurement result when differential scanning calorimetry is performed on each sample of N d —Fe—Al system having different composition.

FIG. 9 is a diagram showing a measurement result when differential scanning calorimetry was performed on samples of Nd—Fe—Al system having different diameters.

FIG. 10 is a diagram showing a result of measuring a change in magnetization of each sample of Nd—Fe—Al system having different composition.

FIG. 11 shows the relationship between the Fe content and magnetic characteristics in the Nd-Fe-Al system. FIG. 11 (A) shows the relationship between the Fe content and the residual magnetization, and FIG. 11 (B) shows the Fe content. FIG. 11 (C) is a diagram showing the relationship between the Fe content and the maximum magnetic energy product, and FIG. 11 (D) is a diagram showing the relationship between the Fe content and the magnetization.

FIG. 12 is a diagram showing the results of measuring the change in magnetization for samples of different diameters in the Nd-Fe-Al system.

FIG. 13 is a diagram showing a result of measuring a change in magnetization of a ribbon-shaped sample manufactured by a quenching method.

14A and 14B show the relationship between the annealing temperature and the magnetic characteristics in a Nd-Fe-Al- based sample . FIG. 14A shows the relationship between the annealing temperature and the residual magnetization, and FIG. 14B shows the annealing temperature. It is a figure which shows the relationship of coercive force.

FIG. 15 is a diagram showing a relationship between heating temperature and magnetization in an Nd—Fe—Al- based sample .

FIG. 16 is a diagram showing a DSC curve in an Nd—Fe—Al based alloy.

FIG. 17: D of ZrAlNi and ZrAlCu based samples
It is a figure which shows a SC curve.

FIG. 18 is a diagram showing the results of measuring the magnetization change of each sample in the NdFeGa system according to the present invention.

FIG. 19 is a diagram showing a magnetization curve of each sample when the content of Co was changed in the sample having a composition of N d ₆₀ Fe _20-X Co _X Al ₁₀ .

FIG. 20 is a diagram showing a magnetization curve of each sample when the content of Co is changed in the sample having a composition of N d ₇₀ Fe _30-X Co _X Al ₁₀ .

FIG. 21 is a Nd—Fe—Ga-based triangular composition diagram showing an amorphous phase generation region of a quenched material.

FIG. 22 is a Nd—Fe—Ga-based triangular composition diagram showing an amorphous phase generation region of a cast material.

FIG. 23 is a diagram showing a measurement result when differential scanning calorimetry was performed on each sample having a different Nd—Fe—Ga-based composition according to the present invention.

FIG. 24 is a diagram showing measurement results when a differential scanning calorimetry measurement was performed on a sample having a composition of Nd ₅₀ Fe ₄₀ Ga ₁₀ according to the present invention.

FIG. 25 is a diagram showing the results of measuring the change in magnetization for samples of Nd—Fe—Ga system having different compositions.

FIG. 26 is a diagram showing composition dependence of residual magnetization in an Nd-Fe-Ga-based sample.

FIG. 27 is a diagram showing the composition dependence of coercive force in Nd-Fe-Ga based samples.

FIG. 28 is a diagram showing the composition dependence of the maximum magnetic energy product in a Nd—Fe—Ga based sample.

[Explanation of symbols]

2 crucibles 3 molten metal 4 molds 5 Casting space

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akira Takeuchi 3-18 Kitayama, Aoba-ku, Sendai City, Miyagi Prefecture City Life Kitayama Room 103 (56) Reference JP-A-3-36243 (JP, A) JP-A 57-210934 (JP, A) JP 60-191024 (JP, A) JP 61-15944 (JP, A) JP 7-289567 (JP, A) JP 8-131460 (JP, A) JP-A-8-131461 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C22C 45/00 C22C 38/00 303 H01F 1/053 H01F 41/02

Claims (4)

(57) [Claims] 1. An amorphous hard magnetic alloy having the following composition. _{A x - (Fe 1-a} Co a) y - Ga z where A, Nd, Sm, Pr, represents at least one element selected from among Pm, x indicating the set composition ratio,
y and z are atomic%, and satisfy the relations of 50 ≦ x ≦ 75, 10 ≦ y ≦ 45, 5 ≦ z ≦ 15, and a satisfies 0 ≦ a ≦ 0.5. 2. The composition ratio y is expressed in atomic%, and 25 ≦ y ≦
The amorphous hard magnetic alloy according to claim 1, which is in a range of 35. 3. The amorphous hard magnetic alloy according to claim 2 or 3, wherein ferromagnetic clusters having disordered anisotropy are formed. 4. An amorphous alloy casting material, comprising the structure according to claim 1, 2 or 3.