JPH1171646A - Speaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a metallic glass alloy extremely wide in the temp. interval δTx in the supercoolant liq. region, having ferromagnetism at a room temp., capable of producing thickly more than the case of an amorphous alloy thin strip obtained by the conventional liquid rapid-quenching method, furthermore excellent in material strength and more inexpensive than rare earth magnets and to provide a speaker using this metallic glass alloy as the magnetic material for a speaker. SOLUTION: This speaker has magnets 23 and 24 for a speaker composed of a ferromagnetic metallic glass alloy sintered body essentially consisting of Fe, contg. one or >= two kinds of elements R selected from rare earth elements, one or >= two kinds of elements M selected from Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W and Cu, and B. The temp. interval δTx in the supercoolant liq. region expressed by the equation of δTx=Tx-Tg (where Tx denotes the crystallization starting temp., and Tg denotes the glass transition temp.) is regulated to >=20 deg.K.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speaker, and more particularly to a speaker using a hard magnetic metallic glass alloy as a speaker magnet material.

[0002]

2. Description of the Related Art As a conventional speaker, a pole piece made of iron, a cylindrical yoke provided outside the pole piece with a gap therebetween, and a speaker arranged above and below a gap between the pole piece and the yoke, respectively. A ring-shaped speaker magnet and a cone-shaped diaphragm are generally known. Also, a voice coil is arranged between the magnetic gaps created by the speaker magnets,
Further, the voice coil is connected to a cone-shaped diaphragm. When an audio current flows from the amplifier to the audio coil, this type of speaker makes a motion in response to the audio current, and further moves the connected cone-shaped diaphragm to emit sound as sound. I have. Meanwhile, in a conventional speaker, a ferrite magnet or an alnico (A1-Ni-Co-Fe-based) magnet is used as a speaker magnet material, and Nd is used as a magnet material having performance superior to these magnets. -Fe-B-based magnets or Sm-Co-based magnets have been used, and many studies using new alloy magnets such as Sm-Fe-N-based magnets have been made for higher performance.

However, Nd-Fe-B magnets, S
In m-Co magnets and Sm-Fe-N magnets,
Nd of 10 at% or more or Sm of 8 at% or more is required, and there is a drawback that the production cost is higher than ferrite magnets and alnico magnets due to the large amount of expensive rare earth elements used. Further, the Sm-Co based magnet is not practical because it is more expensive than the Nd-Fe-B based magnet. On the other hand, alnico magnets have a problem that the coercive force is too small although the cost is lower than the rare earth magnets as described above. For this reason, there has been a demand for a low-cost speaker magnet material having hard magnetic characteristics more than ferrite magnets.

[0004] Therefore, adoption of an amorphous alloy has been considered as a magnet material for a spiker to meet the above demand. Conventionally, an amorphous alloy is an Fe-PC-based amorphous alloy first manufactured in the 1960s, and an Fe-PC-based amorphous alloy manufactured in the 1970s (Fe, Co, N
i) -PB-based alloy, (Fe, Co, Ni) -Si-B-based alloy, 1
(Fe, Co, Ni) -M manufactured in the 980s
(Zr, Hf, Nb) alloy, (Fe, Co, Ni) -M
(Zr, Hf, Nb) -B alloys are known. However, all of these amorphous alloys are 10 ⁵
It is necessary to rapidly cool at a cooling rate of K / s level, and the thickness of the manufactured product is a thin ribbon of 50 μm or less. Therefore, there is a problem that the thickness is too thin to be applied to a magnet for a spiker. . In order to solve such a problem, adoption of a thick bulk bonded magnet is considered.
This bonded magnet is made of a magnetic powder produced by rapidly quenching a molten metal of an alloy mainly composed of an Nd ₂ Fe ₁₄ B phase, Fe ₃ B
Since the magnetic powder of -Nd ₂ Fe ₁₄ B ₁ exchange spring is mixed with a binder of rubber or plastic and molded by compression molding or injection molding, the magnetic properties are low due to the interposition of the binder, and However, there is a problem that the material strength is weak.

[0005]

The present inventors have studied the use of a metallic glass alloy (glassy alloy) as a magnet material for a speaker. Metallic glass alloys are a class of multi-element alloys that have a large supercooled liquid region in the state of the supercooled liquid region before crystallization. In addition, some metallic glass alloys have been found to be bulk alloys that are thicker than thin ribbons of amorphous alloys manufactured by a conventionally known liquid quenching method. As such a metallic glass alloy, 198
From 8 years to 1991, Ln-Al-TM, Mg-L
Compositions such as n-TM and Zr-Al-TM (where Ln represents a rare earth element and TM represents a transition metal) are known. However, none of these conventionally known metallic glass alloys has magnetism at room temperature, and in this respect, there is a great industrial restriction when viewed as a speaker magnet material. Therefore, conventionally, research and development of a metallic glass alloy which has a hard magnetism at room temperature and can obtain a thick bulk material has been promoted.

Here, in the alloys of various compositions, even if the state of the supercooled liquid region is shown, the temperature interval ΔTx between these supercooled liquid regions, that is, the crystallization start temperature (Tx) and the glass transition temperature (Tg) In general, the value of (Tx-Tg) is generally small, and in reality, it is poor in metallic glass forming ability and impractical. The presence of an alloy that has a temperature range of and can form metallic glass by cooling is
It is of great interest in metallurgy since it is possible to overcome the limitation of the thickness of a conventionally known amorphous alloy as a ribbon. However, whether it can be developed as an industrial material depends on finding a metallic glass alloy that exhibits ferromagnetism at room temperature.

[0007] The present invention has been made in view of the above circumstances, the temperature interval of the supercooled liquid region is extremely wide, has a hard magnetism at room temperature, and is smaller than the amorphous alloy ribbon obtained by the conventional liquid quenching method. An object of the present invention is to obtain a metal glass alloy which can be manufactured thickly, has excellent material strength, and is lower in cost than a rare earth magnet, and provides a speaker using the metal glass alloy as a speaker magnet material.

[0008]

The loudspeaker according to the present invention comprises Fe as a main component, one or more elements R selected from rare earth elements, Ti, Zr, Hf,
ΔTx containing one or more elements M selected from V, Nb, Ta, Cr, Mo, W, and Cu, and B;
= Tx-Tg (where Tx indicates the crystallization start temperature and Tg indicates the glass transition temperature). A hard magnetic metallic glass alloy sintered body having a temperature interval ΔTx of 20K or more in a supercooled liquid region represented by the following equation: Characterized by having a speaker magnet comprising:

The above-mentioned hard magnetic metallic glass alloy may be one represented by the following composition formula. _{Fe 100-xyzw R x M y} T z B w where, T is one or two elements selected Co, from among Ni, x indicating the composition ratio, y, z, w in atomic% 2 atomic% ≦ x ≦ 15 atomic%, 2 atomic% ≦ y ≦ 20
Atomic%, 0 atomic% ≦ z ≦ 20 atomic%, 10 atomic% ≦ w ≦
30 atomic%.

The hard magnetic metallic glass alloy may be represented by the following composition formula. _{Fe 100-xyzwt R x M y} T z B w L t where, T is one or two elements selected Co, from among Ni, x indicating the composition ratio, y, z, w, t Is atomic%, 2 atomic% ≦ x ≦ 15 atomic%, 2 atomic% ≦ y ≦
20 atomic%, 0 atomic% ≦ z ≦ 20 atomic%, 10 atomic% ≦
w ≦ 30 atomic%, 0 atomic% ≦ t ≦ 5 atomic%, and the element L is Ru, Rh, Pd, Os, Ir, Pt, Al, S
1 selected from i, Ge, Ga, Sn, C, and P
A species or two or more elements. The hard magnetic metallic glass alloy is subjected to a heat treatment so that the α-Fe phase and Fe ₃ B
A crystalline phase consisting of one or two phases, and Nd ₂ Fe ₁₄
What precipitated the crystalline phase which consists of B phase may be used. In the present invention, even if a small amount of impurities inevitable in production, for example, rare earth oxides, can be regarded as within the technical concept of the hard magnetic metallic glass alloy according to the present invention.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a speaker according to the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing a first embodiment of the speaker of the present invention. In the figure, reference numeral 21 denotes a pole piece made of iron, 22 denotes a cylindrical dust core (yoke) provided outside the pole piece 21 with a gap, and 23 and 24 denote the pole piece 21 and the yoke 22. Speaker magnets are arranged above and below the gap, respectively, and 25 is a cone-shaped diaphragm. The speaker magnets 23 and 24 are made of a hard magnetic metal glass alloy sintered body, and are formed in a ring shape. An audio coil (not shown) is disposed between the magnetic gaps formed by the speaker magnets 23 and 24, and the audio coil is connected to the cone-shaped diaphragm 25. When the audio current flows from the amplifier to the audio coil, the loudspeaker having such a configuration moves in response to the audio current, and is connected to the cone-shaped diaphragm 25 connected thereto.
Can be radiated as sound.

Next, the hard magnetic metallic glass alloy constituting the above-mentioned sintered hard magnetic metallic glass alloy will be described. One of the hard magnetic metallic glass alloys used in the present invention is mainly composed of Fe, and one or more elements R selected from rare earth elements, and Ti, Zr, Hf, V, N
This is realized by a component system in which a predetermined amount of one or more elements M selected from b, Ta, Cr, Mo, W, and Cu and B is added. Further, in the above component system, ΔTx =
It is necessary that the temperature interval ΔTx of the supercooled liquid region represented by the equation of Tx−Tg (where Tx indicates a crystallization start temperature and Tg indicates a glass transition temperature) is 20K or more. In the above composition system, when Cr is always contained, ΔTx is preferably 40K or more.

One of the hard magnetic metallic glass alloys used in the present invention is represented by the following composition formula. In _{Fe 100-xyzw R x M y} T z B w this composition formula, T is one or two elements selected Co, from among Ni, x indicating the composition ratio,
y, z, w are 2 atomic% ≦ x ≦ 15 atomic%, 2 atomic% ≦
It is preferable to satisfy the following condition: y ≦ 20 at%, 0 at% ≦ z ≦ 20 at%, 10 at% ≦ w ≦ 30 at%.

Another example of the hard magnetic metallic glass alloy used in the present invention is represented by the following composition formula. In _{Fe 100-xyzwt R x M y} T z B w L t this composition formula, T is one or two elements selected Co, from among Ni, x indicating the composition ratio,
y, z, w, and t are 2 atomic% ≦ x ≦ 15 atomic%, 2 atomic% ≦ y ≦ 20 atomic%, 0 atomic% ≦ z ≦ 20 atomic%, 10 atomic%
Atomic% ≦ w ≦ 30 atomic%, 0 atomic% ≦ t ≦ 5 atomic%, and the element L is Ru, Rh, Pd, Os, I
One or more elements selected from r, Pt, Al, Si, Ge, Ga, Sn, C, and P. Also, hard magnetic glassy alloy used in the present invention, the _{Fe 100-xyzw R x M y} T z B w a composition formula or the F
In _{e 100-xyzwt R x M y} T z B w L t a composition formula,
X indicating the composition ratio is atomic%, and 2 atomic% ≦ x ≦ 12 atomic%
Is preferably in the range of 2 atomic% ≦ x ≦ 8 atomic%
More preferably, it is within the range. Further, the hard magnetic metallic glass alloy used in the present invention is the above Fe _100-xyzw
R _x M _y T _z B _w a composition formula or the _F e _100-xyzwt
In _{R x M y T z B w} L t a composition formula, y showing the composition ratio
Is atomic%, preferably in the range of 2 atomic% ≦ y ≦ 15 atomic%, and more preferably in the range of 2 atomic% ≦ y ≦ 6 atomic%. Also, hard magnetic glassy alloy used in the present invention, the _{Fe 100-xyzw R x M y} T z B w a composition formula or the _{F e 100-xyzwt R x M} y T z B w L t
In the composition formula, z indicating the composition ratio is atomic%, and
The range is preferably 1 atomic% ≦ z ≦ 20 atomic%, and more preferably 2 atomic% ≦ z ≦ 10 atomic%.

Further, hard magnetic glassy alloy used in the present invention, the _{Fe 100-xyzw R x M y} T z B w a composition formula or the _{F e 100-xyzwt R x M} y T z B w L t In the composition formula, the element M is represented by (Cr _1-a M ′ _a ),
M ′ is Ti, Zr, Hf, V, Nb, Ta, Mo, W,
It may be one or more elements selected from Cu, wherein 0 ≦ a ≦ 1. Further, in the hard magnetic metallic glass alloy represented by such a composition formula, a represents a composition ratio in the above composition formula.
Is preferably in the range of 0 ≦ a ≦ 0.5. In the present invention, the hard magnetic metallic glass alloy is subjected to a heat treatment, and a crystalline phase composed of one or two of an α-Fe phase and an Fe ₃ B phase and a crystalline phase composed of an Nd ₂ Fe ₁₄ B phase It is preferable that the phase be precipitated. In this hard magnetic metallic glass alloy, a mixed phase state of a soft magnetic phase in which an α-Fe phase or the like is precipitated and a hard magnetic phase in which an Nd ₂ Fe ₁₄ B phase or the like is formed is formed. It shows the characteristics of an exchange spring magnet in which a magnetic phase is magnetically coupled. In the present invention, the one in which the above-described crystalline phase is precipitated is also referred to as a metallic glass alloy. Further, a material having ΔTx is defined as a metallic glass, and is distinguished from an amorphous material having no ΔTx.
In the heat treatment, the hard magnetic metallic glass alloy is
Heating at 00 to 850 ° C, preferably 550 to 750 ° C, is preferable in that a hard magnetic metallic glass alloy having improved coercive force and maximum energy product can be obtained. The hard magnetic metallic glass alloy after the heat treatment (after being heated) is cooled by, for example, water quenching.

"Reason for limiting composition" In the composition system of the hard magnetic metallic glass alloy used in the present invention, the main component Fe
Co is an element that plays a role in magnetism, and is important for obtaining a high saturation magnetic flux density and excellent hard magnetic characteristics. Also, F
ΔTx tends to increase in a component system containing a large amount of e,
By setting the Co content to an appropriate value in a component system containing a large amount of Fe, there is an effect of increasing the value of ΔTx. The combined addition with other elements has the effect of increasing the value of ΔTx without deteriorating the magnetic properties, increasing the Curie point, and lowering the temperature coefficient. In particular,
In order to reliably obtain ΔTx, z indicating the composition ratio of element T
In order to reliably obtain ΔTx of 20K or more, the value of z indicating the composition ratio of T must be 2 atomic%.
It is preferable that ≦ z ≦ 10 atomic%. Also,
If necessary, part or all of Co may be replaced with Ni.

R is a rare earth metal (Y, La, Ce, P
r, Nd, Gd, Tb, Dy, Ho, Er). The R ₂ FeB phase of these compounds causes uniaxial magnetic anisotropy,
Element effective for increasing coercive force (iHc),
The content is preferably in the range of 2 atomic% to 15 atomic%. Further, in order to maintain a high magnetization without reducing the Fe content and maintain a magnetic balance with the coercive force (iHc), it is more preferable that the content be 2 atomic% or more and 12 atomic% or less. Preferably, the content is in the range of 2 at% to 8 at%.

M is Ti, Zr, Hf, V, Nb, Ta,
One or two selected from Cr, Mo, W, and Cu
More than one kind of element. These are effective elements for forming an amorphous material, and are preferably in the range of 2 to 20 atomic%. Further, in order to obtain high magnetic properties, the content is more preferably 2 to 15 atomic%, and still more preferably 2 to 6 atomic%. Of these elements M, Cr is particularly effective. Cr
Represents a part of Ti, Zr, Hf, V, Nb, Ta, M
It can be replaced by one or more elements selected from o, W, and Cu. When the replacement ratio is in the range of 0 ≦ a ≦ 1, a high ΔTx can be obtained. Although it can be obtained, the range of 0 ≦ c ≦ 0.5 is preferable in order to reliably obtain a particularly high ΔTx. In addition, Cu of the element M has an effect of preventing the crystal from becoming coarse when crystallized to be hard magnetic, and has an effect of improving hard magnetic characteristics.

B has a high ability to form an amorphous phase. In the present invention, B is added in a range of 10 at% to 30 at%.
If the addition amount of B is less than 10 at%, it is not preferable because ΔTx disappears, and if it is more than 30 at%, it is not preferable because amorphous cannot be formed.
In order to obtain higher amorphous forming ability and better magnetic properties, it is more preferable that the content be 14 atomic% or more and 20 atomic% or less.

In the above composition system, further, R represented by L
u, Rh, Pd, Os, Ir, Pt, Al, Si, G
One, two or more elements selected from e, Ga, Sn, C, and P can be added. In the present invention, these elements can be added in a range of 0 atomic% to 5 atomic%. These elements are added mainly for the purpose of improving the corrosion resistance. If the content is out of this range, the hard magnetic properties deteriorate. Outside of this range, the glass forming ability is undesirably deteriorated.

Next, a description will be given of a production example of a speaker magnet made of a hard magnetic metallic glass alloy sintered body having the above composition. FIG. 2 shows a main part of one example of a discharge plasma sintering apparatus suitably used for manufacturing a speaker magnet made of a hard magnetic metallic glass alloy sintered body according to the present invention. The tying device includes a cylindrical die 41, an upper punch 42 and a lower punch 43 inserted into the die 41, and a punch electrode that supports the lower punch 43 and also serves as one of electrodes when a pulse current to be described later flows. 44, a punch electrode 45 which presses the upper punch 42 downward and causes a pulse current to flow, and a thermocouple 47 for measuring the temperature of the powder raw material 46 sandwiched between the upper and lower punches 42 and 43. Is configured as

FIG. 4 shows the overall structure of the above-mentioned spark plasma sintering apparatus. The discharge plasma sintering apparatus A shown in FIG. 4 is a type of discharge plasma sintering machine called Model SPS-2050 manufactured by Sumitomo Coal Mining Co., Ltd., and has a structure shown in FIG. 2 as a main part. . In the device shown in FIG.
It has an upper base 51 and a lower base 52, and a chamber 53 is provided in contact with the upper base 51, and most of the structure shown in FIG. 2 is housed inside the chamber 53. The upper and lower punches 42, 4
It is configured such that the raw material powder (powder or granular material) 46 to be filled in between 3 can be maintained under a desired atmosphere such as an inert gas atmosphere. 2 and 4, the energizing device is omitted, but the upper and lower punches 42 and 43 and the punch electrode 4 are not shown.
An energizing device provided separately is connected to the power supply devices 4 and 45, and a pulse current as shown in FIG.
2, 43 and the punch electrodes 44, 45 so as to be able to conduct electricity.

In order to manufacture a speaker magnet made of a hard magnetic metal glass alloy sintered body using the discharge plasma sintering apparatus having the above structure, a raw material powder 46 for molding is prepared. In order to produce the raw material powder 46, for example, elemental elemental powder or elemental lump (which may be partially alloyed in advance) of each component of the hard magnetic metallic glass alloy having the above composition system is prepared, and these are prepared. Elemental elemental powder or elemental elemental lump is mixed, and then the mixed powder is melted in a crucible or other melting apparatus in an inert gas atmosphere such as Ar gas to obtain a molten alloy having a predetermined composition. Next, this alloy melt is poured into a mold and gradually cooled, by a casting method, or by a quenching method using a single roll or twin rolls, and further, by a submerged spinning method or a solution extraction method, or by a high-pressure gas spraying method. , A ribbon, a linear body, a powder, etc., and a step of pulverizing and pulverizing other than powder.

Next, when the raw material powder 46 is prepared, it is put between the upper and lower punches 42 and 43 of the spark plasma sintering apparatus shown in FIG. 2 or FIG. At the same time, a pulse current as shown in FIG. 3 is applied to the raw material powder 46 and the material is heated and molded at the same time as applying pressure from above and below with the punches 42 and 43. In this discharge plasma sintering process, the temperature of the raw material powder 46 can be quickly raised at a predetermined speed by the supplied current, and the temperature of the raw material powder 46 can be strictly controlled according to the value of the supplied current. Temperature control can be performed much more accurately than heating by sintering, and sintering can be performed under ideal conditions as designed in advance.

In the present invention, the sintering temperature needs to be 300 ° C. or higher in order to solidify and mold the raw material powder. However, the hard magnetic metallic glass alloy used as the raw material powder has a large supercooled liquid. Since it has a temperature interval ΔT _x (T _x −T _g ), a high-density sintered body can be preferably obtained by pressure sintering in this temperature range.
Further, the sintering temperature monitored by the mechanism of the spark plasma sintering apparatus is lower than the temperature applied to the powder sample because the sintering temperature is the temperature of the thermocouple installed in the mold.

In the present invention, the rate of temperature rise during sintering is preferably 10 ° C./min or more. The pressure during sintering is preferably 3 t / cm ² or more because a sintered body cannot be formed if the pressure is too low.
Further, the obtained sintered body may be subjected to a heat treatment, whereby the magnetic properties can be improved. The heat treatment temperature at this time is 500 to 850 ° C, preferably 550 to 75 ° C.
Heating at 0 ° C. is preferable in that a hard magnetic metallic glass alloy sintered body having improved coercive force and maximum energy product can be obtained. The heating rate during the heat treatment is 2
0 ° C./min or more, preferably 20 ° C./min to 80 ° C./min, more preferably 40 ° C./min to 80 ° C./min.

The hard magnetic metallic glass alloy sintered body thus obtained has the same composition as the hard magnetic metallic glass alloy used as the raw material powder, and has a temperature interval ΔT _{x in the} supercooled liquid region. It is extremely wide and has excellent hard magnetic properties at room temperature.It is bulky and thicker than the amorphous alloy ribbon obtained by the conventional liquid quenching method.It is also interposed with a binder such as rubber or plastic. Therefore, there is an advantage that the magnetic properties are good and the material strength is high. Further, in this hard magnetic metallic glass alloy sintered body, good magnetic properties can be obtained even if the amount of the rare earth element used is small, so that the conventional Sm-Co based magnet or Nd
-It can be lower in cost than Fe-B based magnets and has better hard magnetic properties than conventional ferrite or alnico magnets.

Further, Ru, Rh, Pd,
Os, Ir, Pt, Al, Si, Ge, Ga, Sn,
A material to which one or more elements selected from C and P are added has excellent corrosion resistance and good rust prevention. Further, the bulk hard magnetic metallic glass alloy sintered body can exhibit better magnetism by heat treatment. Therefore, in the speaker of the first embodiment, since the speaker magnets 23 and 24 made of the hard magnetic metal glass alloy sintered body as described above are provided,
High performance is obtained. In the above-described embodiment, a case has been described in which a bulk hard magnetic metal glass sintered body is obtained by a method in which a raw material powder made of a hard magnetic metal glass alloy is formed by discharge plasma sintering. A bulk hard magnetic metallic glass sintered body can also be obtained by pressure sintering by a method such as an extrusion method.

FIG. 5 is a sectional view showing a second embodiment of the speaker of the present invention. In the figure, reference numerals 31 and 32 denote a pair of pole pieces made of a pair of upper and lower irons opposed to each other, 33 a speaker magnet disposed between the pole pieces 31 and 32, and 34 a pole magnet 31 and 32 and a speaker. A cylindrical yoke 35 is provided outside the magnet 33 with a gap, 35 is a cone-shaped diaphragm, and 36 is a magnetic shield cover. The speaker magnet 33 is made of the above-described hard magnetic metallic glass alloy sintered body, and is formed in a ring shape. The pole pieces 31 and 32 and the magnet 33 are attached to the magnetic shield cover 36 by bolts 37, washers 38 and nuts 39. The loudspeaker of the second embodiment has substantially the same effects as the loudspeaker of the above-described first embodiment because the loudspeaker magnet 33 made of the above-described sintered metal glass alloy is provided.

[0030]

【Example】

(Production Example 1 of Metallic Glass Alloy Strip and Sintered Body) Fe
, Co, Nd, a single pure metal of Cr or Zr and a pure boron crystal were mixed in an Ar gas atmosphere and arc melted to produce a mother alloy. Next, this master alloy was melted in a crucible, and was heated in an argon gas atmosphere of 60 cmHg.
00r. p. Injection pressure 0.50 from the 0.35-0.45 mm diameter nozzle at the lower end of the crucible to the copper roll rotating at m
By carrying out a single roll method of blowing and quenching at a rate of kgf / cm ² , a metallic glass alloy ribbon sample having an amorphous single phase structure was produced. The surface of the single roll of the single roll liquid quenching device used here was finished with # 1500. The gap between the single roll and the tip of the nozzle was 0.30 mm.

Further, the obtained metallic glass alloy ribbon sample was pulverized by pulverizing it in the air using a rotor mill. Among the obtained powders, those having a particle size of 53 to 105 μm were selected and used as raw material powders in the subsequent steps. About 2g
The above raw material powder was filled into a die made of WC by using a hand press, and then charged into a die 41 shown in FIG. 2, and the inside of the chamber was punched in an atmosphere of 3 × 10 ⁻⁵ torr with upper and lower punches. Pressurizing at 42 and 43 and sintering by applying a pulse wave to the raw material powder from the power supply device,
A sintered body was obtained. As shown in FIG. 3, the pulse waveform is assumed to flow for 12 pulses and then to pause for 2 pulses.
The raw material powder was heated with a current of ４4800 A. The sintering conditions here were such that the sample was heated from room temperature to the sintering temperature while applying a pressure of 6.5 t / cm ² and held for about 5 minutes. The rate of temperature rise during sintering was 40 ° C./min.
The obtained sample was subjected to X-ray diffraction and differential scanning calorimetry (DS
C), the sample was observed with a transmission electron microscope (TEM), and its magnetic properties were measured at 15 kOe and room temperature with a vibrating sample magnetometer (VSM).

FIG. 6 shows Fe ₆₃ Co ₇ Nd _10-x Zr _x B
₂₀ shows a DSC curve obtained by heating a ribbon sample having a composition of ₂₀ (x = 0, 2, 4, 6 atom%) at a heating rate of 0.67 K / sec in the range of 127 to 827 ° C. Things. From FIG. 6, in the case of the metallic glass alloy ribbon sample having the composition of Fe ₆₃ Co ₇ Nd ₁₀ B ₂₀ , three or more exothermic peaks are observed, and it is considered that crystallization occurs in three or more stages. Although the glass transition temperature Tg is not observed below the onset temperature Tx, when Zr is added and the amount added is increased, the T
It can be seen that an endothermic reaction considered to correspond to Tg is observed at a temperature of x or less.

FIG. 7 shows Fe ₆₃ Co ₇ Nd _10-x Cr _x B
After vacuum-sealing a sintered body sample having a composition of ₂₀ (x = 0, 2, 4, 6 atom%), the sample was heated to 585 ° C. (85%) using a muffle furnace.
8K) to 750 ° C. (1023 K), showing the results of examining the heat treatment temperature dependence of the magnetic properties when the heat treatment was performed for 300 seconds. From the results shown in FIG. 7, regarding the saturation magnetization, the sample of the example to which Cr was added (x = 2,
Samples 4 and 6) were samples of the comparative example to which Cr was not added (x =
It can be seen that the value is larger than 0) and higher than 1T. Regarding the remanent magnetization, in all samples,
Samples of the examples which show a tendency to increase as the heat treatment temperature rises and where Cr is added (x = 2, 4, 6)
Is larger than that of the sample of Comparative Example (x = 0) to which Cr was not added, and increased to about 0.8T, showing that the squareness ratio was very high. For the coercive force, Cr
The sample of the example (x = 2, 4, 6) to which Cr was added was lower than the sample of the comparative example (x = 0) to which Cr was not added irrespective of the amount of added Cr and the heat treatment temperature. It can be seen that the energy product is larger for the samples with x = 4,6.

FIG. 8 shows I-H loops before and after heat treatment of a sintered body produced using a raw material powder obtained by pulverizing a ribbon sample having a composition of Fe ₆₃ Co ₇ Nd ₄ Cr ₆ B _20. It is a thing. FIG. 9 shows Fe ₆₃ Co ₇ Nd for comparison.
About ₁₀ B ₂₀ becomes ribbon sample of the composition with using a raw material powder obtained by crushing was produced sintered bodies are those obtained before and after I-H loop heat treatment. As is clear from FIGS. 8 and 9, in the case of the sintered body having the composition of Fe ₆₃ Co ₇ Nd ₁₀ B ₂₀ of the comparative example, the quenched state without heat treatment (as
-Q) shows soft magnetism, and shows hard magnetism by crystallization heat treatment. In addition, at the initial stage of crystal precipitation, the precipitated phase is very fine, and the coercive force decreases and the squareness deteriorates as the heat treatment temperature increases. It can be seen that grain growth occurs. On the other hand, the Fe ₆₃ Co ₇ Nd ₄ Cr of the embodiment to which Cr was added
For ₆ B ₂₀ a composition of the metallic glass alloy sintered body, those remains of rapid cooling non-heat-treated show a soft shows a hard magnetic by crystallization heat treatment. Further, the saturation magnetization and the remanent magnetization are very high, and the coercive force increases from the initial stage of crystal precipitation, and reaches a maximum after the first stage of crystallization.
It can be seen that it slightly decreases. This shows that the maximum energy product shows a larger value than the comparative example. From this, it is understood that the sintered metal glass alloy of the example is an exchange spring magnet composed of a soft magnetic phase and a hard magnetic phase, and can be suitably used as a speaker magnet.

(Production Example 2 of Metallic Glass Alloy Strip and Sintered Body) A single pure metal of Fe, Co, Nd, Cr or Zr, and a pure boron crystal are mixed in an Ar gas atmosphere and arc-melted. A mother alloy was produced. Next, this master alloy was melted with a crucible, and a single roll method was carried out in the same manner as in Production Example 1 described above to obtain a sample of a metallic glass alloy ribbon. Further, the obtained metallic glass alloy ribbon sample was pulverized in the same manner as in Production Example 1 to prepare a raw material powder,
A sintered body sample was prepared using this raw material powder. The obtained sample is analyzed by X-ray diffraction and differential scanning calorimetry (DSC), observed by a transmission electron microscope (TEM), and measured for magnetic properties at room temperature at 15 kOe by a vibrating sample magnetometer (VSM). did.

Next, the manufactured Fe ₆₃ Co ₇ Nd _10-x Cr _x B
After vacuum-sealing a sintered body sample having a composition of ₂₀ (x = 2, 4, 6 at%), the sample was heated to 585 ° C. (858) using a muffle furnace.
K) to 750 ° C. (1023 K), and the results of examining the heat treatment temperature dependence of the magnetic properties when the heat treatment was performed for a holding time of 300 seconds are shown in Table 1. For comparison, Fe ₆₃ Co ₇ Nd
After vacuum-sealed ₁₀ sintered body samples B ₂₀ having a composition, 660 ° C. using a muffle furnace (933K) ~750 ℃ (102
3K) The results of examining the heat treatment temperature dependence of the magnetic properties when the heat treatment was performed for a holding time of 300 seconds are also shown in Table 1. Table 1 also shows the densities of the metallic glass alloy ribbon samples of each composition in the quenched state manufactured by the single roll method.

[0037]

[Table 1]

In Table 1, as-Q is an alloy ribbon sample which has not been heat-treated and remains in a quenched state, Ta is a heat treatment temperature, Is is a saturation magnetization, Ir is a residual magnetization, Ir / Is is a squareness ratio, and iHc is a preservation temperature. The magnetic force, (BH) max, indicates the maximum energy product.

From the results shown in Table 1, with respect to the saturation magnetization, the sample of the example to which Cr was added was larger than the sample of the comparative example to which Cr was not added, and showed a high value of about 1T or more. Recognize. Regarding the remanent magnetization, the sample of the example to which Cr was added was larger than the sample of the comparative example to which Cr was not added, and increased to about 0.6 to 0.9 T, showing a very high squareness ratio. You can see that it is.
Next, the temperature interval ΔTx of the supercooled liquid region was obtained from a DSC curve obtained by heating the sintered body samples having the respective compositions shown in Table 1 at a heating rate of 0.67 K / sec in the range of 127 to 827 ° C.
As a result, ΔTx was not observed in the amorphous alloy ribbon sample having the composition of Fe ₆₃ Co ₇ Nd ₁₀ B _{20 of the} comparative example, and the metallic glass alloy ribbon sample having the composition of Fe ₆₃ Co ₇ Nd ₈ Cr ₂ B _{20 was} obtained. Then, ΔTx = 51K, Fe ₆₃ Co ₇ Nd ₆ C
For a metallic glass alloy ribbon sample having a composition of r ₄ B ₂₀ , ΔTx =
ΔTx = 52K in a metallic glass alloy ribbon sample having a composition of 40K and Fe ₆₃ Co ₇ Nd ₄ Cr ₆ B ₂₀ . In addition,
In a metallic glass alloy ribbon sample having a composition of Fe ₆₃ Co ₇ Nd ₄ Zr ₆ B ₂₀ , ΔTx = 35 K, and it was found that when Cr was added, the temperature interval ΔTx in the supercooled liquid region was wider.

(Production Example 3) Fe, Co, Nd, and Z
A single pure metal of r and a pure boron crystal were mixed in an Ar gas atmosphere and arc melted to produce a mother alloy. Next, this master alloy was melted in a crucible, and 4,000 rpm in an argon gas atmosphere of 60 cmHg. p. m by a single roll method in which the copper roll is blasted from a 0.35 to 0.45 mm diameter nozzle at the lower end of the crucible at an injection pressure of 0.50 kgf / cm ² and quenched. Metallic glass alloy ribbon samples were produced. The surface of the single roll of the single roll liquid quenching device used here was #
It was finished at 1500. The gap between the single roll and the tip of the nozzle was 0.30 mm.
Next, the relationship between the heating temperature (K) and the calorific value of the metallic glass alloy ribbon sample having the composition of Fe ₆₃ Co ₇ Nd ₆ Zr ₄ B ₂₀ was examined. The result is shown in FIG. FIG. 10 shows that Fe ₆₃ Co
D of a metallic glass alloy ribbon sample having the composition ₇ Nd ₆ Zr ₄ B ₂₀
It shows an SC curve. Further, Fe ₆₃ Co ₇ Nd ₆ Z
The relationship between the heating temperature (K) and the elongation rate of a metallic glass alloy ribbon sample having a composition of r ₄ B ₂₀ was examined. The result is shown in FIG. In FIG. 11, the curve (b) is Fe ₆₃ Co ₇ Nd ₆ Zr ₄
TMA curve of the glassy alloy ribbon sample B ₂₀ a composition,
Curve (c) is a DTMA curve. As is clear from FIGS. 10 to 11, the DSC curves show exothermic peaks around 920K and 960K, and the DTMA curve
Since the absolute value of the differential value near (K) is large, 900
(K), the sample is easy to stretch, and the TMA curve
It can be seen that the sample rapidly expands in the temperature range of 50 to 950 (K) as the temperature rises. This indicates that viscous flow occurs in the supercooled liquid temperature range. Solidification molding utilizing the phenomenon of softening of the amorphous alloy is advantageous for achieving high density.

[0041]

As described above, the loudspeaker according to the present invention comprises Fe, as a main component, one or more elements R selected from rare earth elements, Ti, Zr, Hf,
ΔTx containing one or more elements M selected from V, Nb, Ta, Cr, Mo, W, and Cu, and B;
= Tx-Tg (where Tx indicates the crystallization start temperature and Tg indicates the glass transition temperature). A hard magnetic metallic glass alloy sintered body having a temperature interval ΔTx of 20K or more in a supercooled liquid region represented by the following equation: As a speaker magnet.

The sintered hard magnetic metallic glass alloy used in the present invention has a very wide temperature interval ΔT _{x in} the supercooled liquid region, has excellent hard magnetic properties at room temperature, and has a low temperature in the conventional liquid quenching method. Since it is a bulk material thicker than the obtained amorphous alloy ribbon and does not have a binder such as rubber or plastic interposed, it has the advantages of good magnetic properties and strong material strength. . In addition, in this hard magnetic metallic glass alloy sintered body, good magnetic properties can be obtained even when the amount of the rare earth element used is small, so that the conventional Sm-Co magnet or Nd-Fe-B magnet The cost can be reduced, and the hard magnetic properties are superior to conventional ferrite and alnico magnets. Further, Ru, Rh, Pd, Os, Ir, Pt, Al, S represented by L
1 selected from i, Ge, Ga, Sn, C, and P
The one to which the seed or two or more elements are added has excellent corrosion resistance and good rust prevention.

Further, the hard magnetic metallic glass alloy forming the sintered body is subjected to a heat treatment, and a crystalline phase comprising at least one of an α-Fe phase and an Fe ₃ B phase, and Nd ₂ Fe ₁₄ B By precipitating a crystalline phase composed of a phase, a mixed phase state composed of a soft magnetic phase in which an α-Fe phase or the like is precipitated and a hard magnetic phase in which a Nd ₂ Fe ₁₄ B phase or the like can be formed, An exchange coupling characteristic in which a soft magnetic phase and a hard magnetic phase are combined can be exhibited, and more excellent magnetism can be exhibited. Therefore, in the present invention, a high-performance speaker can be provided by using the above-described sintered hard magnetic metal glass alloy as a speaker magnet.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first embodiment of a speaker of the present invention.

FIG. 2 is a cross-sectional view showing an essential structure of an example of a discharge plasma sintering apparatus suitably used for manufacturing a speaker magnet made of a hard magnetic metallic glass alloy provided in the speaker of the present invention.

3 is a diagram showing an example of a pulse current waveform applied to a raw material powder in the discharge plasma sintering apparatus shown in FIG.

FIG. 4 is a front view showing an overall configuration of an example of a discharge plasma sintering apparatus suitably used for manufacturing a speaker magnet made of a hard magnetic metallic glass alloy provided in the speaker of the present invention.

FIG. 5 is a sectional view showing a second embodiment of the speaker of the present invention.

FIG. 6 shows a quenched state of Fe ₆₃ Co ₇ Nd _10-x Zr _x B ₂₀ (x = 0, 2,
FIG. 4 is a view showing the result of obtaining a DSC curve of a ribbon sample having a composition of 4,6 atomic%).

FIG. 7: Fe ₆₃ Co ₇ Nd _10-x Cr _x B ₂₀ (x = 0,
2,4,6 atomic%)
FIG. 9 is a diagram showing the heat treatment temperature dependence of magnetic properties when heat treatment is performed at 750 ° C. for a holding time of 300 seconds.

FIG. 8 is a diagram showing IH loops before and after heat treatment of a sintered body sample having a composition of Fe ₆₃ Co ₇ Nd ₄ Cr ₆ B ₂₀ .

FIG. 9 is a diagram showing an IH loop of a sintered body sample having a composition of Fe ₆₃ Co ₇ Nd ₁₀ B ₂₀ before and after heat treatment.

FIG. 10 is a view showing a DSC curve of a metallic glass alloy ribbon sample having a composition of Fe ₆₃ Co ₇ Nd ₆ Zr ₄ B ₂₀ .

FIG. 11 is a diagram showing a TMA curve and a DTMA curve of a metallic glass alloy ribbon sample having a composition of Fe ₆₃ Co ₇ Nd ₆ Zr ₄ B ₂₀ .

[Explanation of symbols]

21: Pole piece, 22: Powder magnetic core (yoke), 2
3 ... Speaker magnet, 24 ... Speaker magnet, 25 ...
Cone-shaped diaphragm, 31 ... Pole piece, 32 ... Pole piece, 33 ... Speaker magnet, 34 ... Yoke, 3
5: cone-shaped diaphragm, 36: magnetic shield cover, 3
7 ... bolt, 38 ... washer, 39 ... nut.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Akihiro Makino Alps Electric Co., Ltd., 1-7 Yukitani Otsuka-cho, Ota-ku, Tokyo (72) Inventor Akihisa Inoue 35 Kawamoto Moto Hasekura, Aoba-ku, Sendai, Miyagi Prefecture, Japan House 11-806

Claims (4)

[Claims] 1. A method according to claim 1, wherein one or more elements R containing Fe as a main component and selected from rare earth elements, Ti, Z
r, Hf, V, Nb, Ta, Cr, Mo, W, and Cu, containing one or more elements M and B, and ΔTx = Tx−Tg (where Tx is Starting temperature,
Tg indicates a glass transition temperature. A speaker comprising a speaker magnet made of a hard magnetic metallic glass alloy sintered body having a temperature interval ΔTx of a supercooled liquid region represented by the following formula: 20T or more. 2. The speaker according to claim 1, wherein the hard magnetic metallic glass alloy is represented by the following composition formula. _{Fe 100-xyzw R x M y} T z B w where, T is one or two elements selected Co, from among Ni, x indicating the composition ratio, y, z, w in atomic% 2 atomic% ≦ x ≦ 15 atomic%, 2 atomic% ≦ y ≦ 20
Atomic%, 0 atomic% ≦ z ≦ 20 atomic%, 10 atomic% ≦ w ≦
30 atomic%. 3. The speaker according to claim 1, wherein the hard magnetic metallic glass alloy is represented by the following composition formula. _{Fe 100-xyzwt R x M y} T z B w L t where, T is one or two elements selected Co, from among Ni, x indicating the composition ratio, y, z, w, t Is atomic%, 2 atomic% ≦ x ≦ 15 atomic%, 2 atomic% ≦ y ≦
20 atomic%, 0 atomic% ≦ z ≦ 20 atomic%, 10 atomic% ≦
w ≦ 30 atomic%, 0 atomic% ≦ t ≦ 5 atomic%, and the element L is Ru, Rh, Pd, Os, Ir, Pt, Al, S
1 selected from i, Ge, Ga, Sn, C, and P
A species or two or more elements. 4. The hard magnetic metallic glass alloy is subjected to a heat treatment to form a crystalline phase comprising one or two of an α-Fe phase and an Fe ₃ B phase and a crystalline phase comprising an Nd ₂ Fe ₁₄ B phase. 4. A phase-precipitated material is used.
The speaker according to any one of the above.