JP3385667B2 - Iron-terbium-based magnetostrictive material and method for producing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an actuator element such as an ultrasonic vibrator, and more particularly to a magnetostrictive alloy that produces magnetostriction by magnetic energy and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, ferrite or Ni has been used as a drive element for a fish finder, a processing / cutting tool, an ultrasonic vibrator of a washing machine, or the like.
Although a magnetostrictive material such as a base alloy has been used, except for some special applications, the magnetostrictive material is now replaced by a piezoelectric material as the mainstream. That is, in the case of the conventional magnetostrictive material, the displacement amount (λ) due to the magnetostriction is as small as 10 ⁻⁵ at most, and electromagnetic driving, that is, mounting of the magnet and the coil is an essential condition for obtaining the magnetostrictive effect. Since the device has a large size because it has it, the displacement amount (λ) of the piezoelectric material is as high as 10 ⁻³ to 10 ^−4, and various motors to which conventional electromagnetic conversion is applied. This is because it is superior in responsiveness, generated stress, and displacement accuracy, which cannot be followed by the voice coil system, and has an advantage that the device can be made smaller than the electromagnetic system. However,
Even a piezoelectric material having such excellent characteristics has a drawback that a high voltage is required for its operation, so that it requires careful handling.

However, recently, a so-called giant magnetostrictive material made of an amorphous magnetic material having no regularity in atomic arrangement has been developed and attracted attention. This giant magnetostrictive material is F
e, Co, Ni and other transition metals (TM) and Y, Nd, S
An amorphous intermetallic compound (TRM ₂ ) with a rare earth metal (R) such as m, Gd, Tb, or Dy,
In particular, an iron-terbium (Fe ₂ Tb) -based amorphous magnetic material does not require a high voltage like a piezoelectric material and has no crystal magnetic anisotropy, and thus has a large magnetic permeability,
It is possible to generate a large magnetostriction close to ^-2 .

[0004]

However, since this amorphous magnetic material is isotropic, the maximum saturation magnetic field magnetostriction is lower than that of anisotropic crystalline material, and magnetostriction does not occur unless the magnetic field becomes large. It was Therefore, in a weak magnetic field, the rise of magnetostriction was small and the response was not sufficient.

Therefore, the present invention has been devised to effectively solve the above problems, and its purpose is to provide a novel iron-terbium-based magnetostrictive material which achieves an improvement in response due to the rise of magnetostriction, and The manufacturing method is provided.

[0006]

In order to achieve the above object, the first and second inventions have a composition of (Fe ₂ Tb) _100-XY.
M _X Cu _Y or (Fe ₂ Tb) _100-XY M _X Au _Y (where M is Al or Si, X is 2.5 to 15 atom%, Y
Is 0.5 to 5 atomic%), and is an iron-terbium-based magnetostrictive material characterized by comprising an amorphous alloy in which microcrystals are deposited, and the third invention is
A method in which a terbium-based magnetostrictive material is melted to form an alloy melt, the alloy melt is rapidly cooled at a temperature gradient of 10 ⁴ ° C / sec or more to form an amorphous alloy, and then the amorphous alloy is heat-treated to be microcrystallized. Is. Also,
A fourth invention is that the composition is (Fe ₂ Tb) _100-X M _X (however,
M is Al or Si, 0 <X ≦ 15 atomic% )
Terbium-based amorphous powder is used as a mother particle, and child particles made of Cu or a Cu-based alloy or Au are attached to the periphery of the mother particle to form a capsule powder, and the capsule powder is aggregated under pressure . It is solidified by energization, and Cu or Cu-based alloy or Au microcrystals are formed substantially uniformly in an amorphous alloy.

A supplementary explanation of the present invention will be given below.

In the first and second inventions, (Fe ₂ T
b) _100-XY M _X Cu _Y or (Fe ₂ Tb) _100-XY M _X
The reason why the compounding amount X of Al or Si in Au _Y is limited to the range of 2.5 to 15 atom% is that the effect of microcrystals does not appear at 2.5 atom% or less. This is because if the content is at least%, Fe ₂ Tb as the base material will be diluted and the function as a magnetostrictive alloy will be impaired. Similarly, the reason why the addition amount Y of Cu or Au is limited to 0.5 to 5 atom% is that the uniformization of fine crystals is not achieved at 0.5 atom% or less, and that at 5 atom% or more, On the other hand, the effect is reduced and the cost of the product is increased.

Also, in the third invention, 10 ⁴ ° C / s
The reason for quenching with a temperature gradient of ec or more is 10 ⁴ ℃
This is because the entire material is crystallized and an amorphous state cannot be obtained at less than / sec. The reason why the amorphous alloy is heat-treated is to generate uniform microcrystals in the amorphous alloy so as to have an isotropic property and an anisotropic property similar to a crystalline property. That is, to make amorphous, it is expected that a crystalline uniaxial property will be required, whereas an amorphous structure, which is an aggregate of small crystallites, is expected to be an isotropic property as compared with crystalline anisotropy. This is because that. In crystalline materials with strong anisotropy, the maximum magnetic field (saturation magnetic field) is dominant for strain in the anisotropy direction, but in the amorphous state, as shown in the characteristics, it is very highly saturated like crystals. There is no characteristic. However, the reaction to a low magnetic field may be fast due to the isotropic nature of microcrystalline aggregates. The low magnetic field characteristics are crystalline and there is no reference example. Further, when an amorphous material is subjected to a predetermined heat treatment, the saturation magnetic field magnetostriction is improved like a crystalline material. This means that distortion will not occur unless the magnetic field becomes large at the same time. Therefore, in order to increase the rise of the magnetostriction, the amorphous material is appropriately heat-treated to increase the saturation magnetization and also increase the magnetostriction.

[0010]

Since the first to third inventions have the above-described composition and manufacturing method, fine crystals are uniformly formed in the obtained amorphous material. Therefore, the amorphous isotropic property and the crystalline anisotropy property are combined, and the saturation magnetization and the magnetostriction are increased, so that a rise in a weak magnetic field is possible and the response is improved. The fourth invention is a method of encapsulating iron / terbium-based amorphous powder with Cu or a Cu-based alloy or Au and then solidifying the encapsulation powder by applying current. In addition to providing the same effect as the above-mentioned invention, the manufacturing thereof becomes easier as compared with the third invention.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings.

Example 1 First, a predetermined amount of copper or gold was added to a base material of iron, terbium, silicon or iron, terbium, and aluminum, and these were melted by an arc melting device to obtain four types. After producing the mother alloy molten metal, the mother alloy molten metal was melted by a single-roll liquid quenching apparatus.
It is rapidly cooled at a temperature gradient of 0 ⁴ to 10 ⁶ ° C / sec to become amorphous, and then these 4 types of amorphous alloys are vacuum-sealed at 3.6 kg and heat-treated (575 ° C, 1 h annealing) to perform microcrystallization. Samples A, B, C and D having the following compositions were prepared. And each of these sample A,
The relationship between the magnetostriction of B, C, and D and the magnetic field is evaluated, and the result is
1 and 2 together with Samples E and F to which copper or gold is not added and Samples A ', B', C'and D'in the amorphous state (as-Q) not subjected to the heat treatment as described above (vertical axis). Is the magnitude of magnetostriction (magnetostriction), and the horizontal axis is the magnetic field strength (KA / m)). The magnetostriction was measured by using a conventionally known measuring device by the electrostatic capacitance method as shown in FIG. The component unit of each sample is atomic%. Sample A: (Fe ₂ Tb) _96.5 Si _2.5 Cu _1.0 (575 ° C., 1 h annealing) Sample B: (Fe ₂ Tb) _96.5 Si _2.5 Au _1.0 〃 Sample C: (Fe ₂ Tb) _96.5 Al _2.5 Cu _1.0 〃 Sample D: (Fe ₂ Tb) _96.5 Al _2.5 Au _1.0 〃 Sample A ': (Fe ₂ Tb) _96.5 Si _2.5 Cu _1.0 Sample B': (Fe ₂ Tb) _96.5 Si _2.5 Au _1.0 sample C ′: (Fe ₂ Tb) _96.5 Al _2.5 Cu _1.0 sample D ′: (Fe ₂ Tb) _96.5 Al _2.5 Au _1.0 sample E: (Fe ₂ Tb) _97.5 Si _2.5 (575 ° C., 1 h annealing) sample F: (Fe ₂ Tb) _97.5 Al _2.5 〃 As a result, as shown in FIGS. 1 and 2, all of the amorphous samples A ′, B ′, C ′, D ′ and Cu, Au, which were not heat-treated, In the case of samples E and F not added, 1 The high magnetic field exceeding 0 kA / m, but all exhibited high magnetostriction constant, it can be seen that a low magnetostriction constant is less low magnetic field 100 KA / m. This means that the magnetostriction effect hardly appears in a low magnetic field and the response is poor. On the other hand, in samples A, B, C, and D to which Cu and Au were added and heat-treated, the elongation rate of magnetostriction in a high magnetic field exceeding 100 KA / m was lower than that of each sample, but 1
It can be seen that magnetostriction is remarkably generated in a low magnetic field of 00 KA / m or less, particularly 50 to 100 KA / m. This shows that the samples A, B, C and D according to the present invention exhibit excellent responsiveness in a low magnetic field. (Example 2) First, Fe ₂ Tb and Si were each added to an alumina crucible 9 times.
After being added at a ratio of 7.5 atomic% and 2.5 atomic%, and high-frequency melting to form (Fe ₂ Tb) _97.5 Si _2.5 alloy molten metal, this (Fe ₂ Tb) _97.5 Si _2.5 alloy molten metal has been conventionally known. By using the gas atomizing device of No. 1 to rapidly cool and spray at a gas pressure of 70 Kg / cm ² to form an amorphous powder having a particle size of 100 mesh or less. (In this example, a powdery amorphous powder was obtained by the gas atomizing method. Alternatively, a ribbon-shaped amorphous powder may be formed by using a single roll method). Next, this amorphous powder is used as the mother particle, and the particle size is 1/1 times that of this amorphous powder.
0.2 wt% of child particles made of a compound alloy containing Cu and Au or CuO of about 0 and Cu were attached and encapsulated to form a capsule powder. Then, the capsule powder is put into a carbon mold (or a mold may be used), and 70
1 by solidifying through discharge under pressure of 0 ° C and 300 Kg / cm ²
After forming a solidified sample of 0φ × 2t, the solidified sample was cut out in the pressing direction (P direction) and in the lateral direction (S direction) with respect to the pressing axis, and its characteristics were evaluated. In Fig. 1, those P directions and
And characteristics in the S direction .

(Example 3) A solidified sample was formed by the same manufacturing method as in Example 2 except that Al was used instead of Si used in Example 2, and its S
The direction was cut out and the characteristics were evaluated. Figure 2 shows the S direction
Show the characteristics .

As a result, as shown in FIGS. 1 and 2, in each of Examples 2 and 3, the S direction shows the same characteristics (575 ° C., 1 h annealing) as the sample prepared in Example 1, and The P direction shows a value of about 80% of the S direction.

[0015]

In summary, according to the present invention, since fine crystals are uniformly formed in the amorphous alloy, it is excellent in a low magnetic field because it has both the isotropy of amorphous and the anisotropy of crystalline. It has an excellent effect that it can exhibit responsiveness.

[Brief description of drawings]

FIG. 1 is a graph showing a relationship between a magnetic field and magnetostriction of a Fe—Tb—Si based magnetostrictive alloy.

FIG. 2 is a graph showing the relationship between the magnetic field and magnetostriction of an Fe—Tb—Al-based magnetostrictive alloy.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shigeo Takita 8 Tsutana, Fujisawa City Kanagawa Prefecture Isuzu Central Research Institute Co., Ltd. (72) Inventor Eiji Okumura 8th Tsuna shelf Fujisawa City Kanagawa Prefecture Isuzu Central Research Co., Ltd. In-house (72) Masayuki Kato 8 Tsutana, Fujisawa, Kanagawa Prefecture Isuzu Central Research Institute (72) Inventor Akihisa Inoue Kawauchi 11-806, Aoba-ku, Sendai, Miyagi Prefecture (56) References 4-246150 (JP, A) JP-A-4-272103 (JP, A) JP-A-4-96203 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C22C 45/00 -45/10 H01L 41/20

Claims (4)

(57) [Claims] 1. A composition of (Fe ₂ Tb) _100-XY M _X Cu
_Y (where, M is Al or Si, X is 2.5 to 15 atomic%, Y is 0.5 to 5 atomic%) an iron characterized in that it consists of crystallites is deposited amorphous alloy -Terbium-based magnetostrictive material. 2. The composition is (Fe ₂ Tb) _100-XY M _X Au.
_Y (where, M is Al or Si, X is 2.5 to 15 atomic%, Y is 0.5 to 5 atomic%) an iron characterized in that it consists of crystallites is deposited amorphous alloy -Terbium-based magnetostrictive material. 3. The composition is (Fe ₂ Tb) _100-XY M _X Cu _Y.
Alternatively, a (Fe ₂ Tb) _100-XY M _X Au _Y (where M is Al or Si, X is 2.5 to 15 atom%, and Y is 0.5 to 5 atom%) iron-terbium-based magnetostrictive material is used. After melting to form an alloy melt, the alloy melt is rapidly cooled at a temperature gradient of 10 ⁴ ° C / sec or more to form an amorphous alloy, and then the amorphous alloy is heat-treated to precipitate fine crystals. Method for manufacturing iron-terbium-based magnetostrictive material. 4. A composition of (Fe ₂ Tb) _100-X M _X (provided that
M is Al or Si, 0 <X ≦ 15 atomic% )
Terbium-based amorphous powder is used as a mother particle, and child particles made of Cu or a Cu-based alloy or Au are attached to the periphery of the mother particle to form a capsule powder, and the capsule powder is aggregated under pressure . A method for producing an iron-terbium-based magnetostrictive material, characterized by solidifying by energization to form Cu or a Cu-based alloy or Au microcrystals in an amorphous alloy substantially uniformly.