JP2003225743A - Method for producing foil and its apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To produce a foil taking in fine grains by dispersing fine grains in a base material. <P>SOLUTION: In a closed vessel 1 holding inactive gas atmosphere, an alloy raw material 6 is charged into a quartz vessel 3 as a melting crucible to make molten alloy 7 by heating with a coil 2 for heating. Into the molten alloy 7, the fine grains 10 produced with a fine grain production device 11, are beforehand added and dispersed. The molten alloy 7 added with the fine grains 10 is made to flow down from a nozzle 4 of the quartz vessel 3 and rapidly cooled and solidified by supplying the molten alloy 7 onto a rotated roll 5 for rapidly cooling to produce the foil 8 taking in the fine grains 10 in the base material. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for producing a foil which is a molding material for thermoelectric semiconductors and the like.

[0002]

2. Description of the Related Art Thermoelectric elements utilizing the Peltier effect and thermoelectric elements utilizing the Seebeck effect are widely used in various fields because of their simple structure, stable characteristics, and easy handling.

The molding material of the thermoelectric semiconductor constituting the thermoelectric element is one or more selected from the group consisting of bismuth (Bi), tellurium (Te), antimony (Sb) and selenium (Se) elements. Alloys containing raw materials are currently in use. These compounds are layered structure compounds and have anisotropy in thermoelectric properties due to the crystal structure.

A liquid quenching method (quenching roll method) is known as a technique for refining and improving the orientation of crystal grains composed of the layered structure compound as described above. This foil quenching apparatus using the liquid quenching method, as shown in the outline of an example in FIG. 4, is equipped with a heating coil 2 on the outer periphery in a sealed container 1 capable of maintaining an inert gas atmosphere. A quartz container 3 serving as a melting crucible is installed, and a water quenching metal quenching roll 5 is arranged immediately below a nozzle 4 at the lower end of the quartz container 3 to heat a heating coil 2. By doing so, the alloy raw material 6 put in the quartz container 3 is melted to form a molten alloy 7, and the molten alloy 7 is made to flow down from the nozzle 4 and supplied to the surface of the quenching roll 5 which is rotating at high speed, and is rapidly cooled. The foil (thin band) 8 as a semiconductor material is manufactured by solidifying. 9 is foil 8
Is a collection container for collecting.

The foil 8 manufactured by the apparatus for manufacturing a foil using the above liquid quenching method maintains a good crystal orientation, but by molding the foil 8 maintaining the crystal orientation, a thermoelectric semiconductor is obtained. When it is made, it is necessary to reduce the thermal conductivity in order to improve the thermoelectric performance. In this case, in order to reduce the thermal conductivity without changing the values of Seebeck coefficient and electrical conductivity of the thermoelectric semiconductor, the grain boundaries are increased so as to reduce the phonon conduction, or the grain size is set to several nm. It is necessary to add and disperse fine particles of a non-conductive substance.

[0006]

However, until now, in order to increase the grain boundaries, it has been impossible to form a polycrystal body of a thermoelectric semiconductor by forming the foil 8 in a sintering process, an extrusion process, or a rolling process. However, it is difficult to add and disperse nano-order fine particles in the base material of the foil 8 and it has not been carried out at this time.

There is also a method of molding a thermoelectric semiconductor by adding and dispersing fine particles to a raw material powder and sintering it. In this method, a better crystal orientation is obtained as compared with a method using a foil. I can't get it.

Therefore, the present invention is intended to make it possible to produce a foil in which fine particles are dispersed and incorporated in a base material.

[0009]

In order to solve the above-mentioned problems, the present invention provides a surface of a quenching roll rotating a molten alloy obtained by melting an alloy raw material in a melting crucible from a nozzle of the melting crucible. In a method and an apparatus for manufacturing a foil, the foil is manufactured by rapidly cooling and solidifying the molten alloy, and at a position from the time when the foil is manufactured from the molten alloy until the flight, the melting in the melting crucible is performed. Fine particles are previously added and dispersed in the alloy so that the fine particles are included before the molten alloy solidifies to form a foil.

If fine particles are added to the molten alloy in advance, a foil having the fine particles incorporated in the base material can be obtained.

Further, the molten alloy obtained by melting the alloy raw material in the melting crucible is supplied from the nozzle of the melting crucible to the surface of the rotating quenching roll to be rapidly solidified to produce the foil. In a foil manufacturing method and apparatus, fine particles are introduced into a portion of the position where the foil is manufactured from the molten alloy until it flies and the molten alloy supplied from the nozzle to the surface of the quenching roll begins to solidify. However, even if the fine particles are included when the molten alloy is solidified, a foil having the fine particles incorporated in the base material can be obtained.

Further, the molten alloy obtained by melting the alloy raw material in the melting crucible is supplied from the nozzle of the melting crucible to the surface of the rotating quenching roll to be rapidly solidified to produce the foil. In a method and apparatus for manufacturing a certain foil, the molten alloy is solidified as a foil at a position between the production of the molten alloy and the flight of the foil so that the fine particles are included in the foil in the downstream forming process. If you add the above particles to the part that fly at high temperature,
Fine particles can be incorporated into the base material crystal structure of the foil by molding.

When the foil produced by using the fine particles made of a non-conductive substance is a semiconductor material, a thermoelectric semiconductor having a low thermal conductivity can be obtained by molding the foil.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention, and a case of manufacturing a foil as a semiconductor material will be described. As shown in FIG. 4, a quartz container 3 as a melting crucible is installed in a sealed container 1 capable of holding an inert gas atmosphere, and an alloy raw material 6 is heated by a heating coil 2 in the quartz container 3. Molten alloy 7 formed by heating and melting,
In a foil manufacturing apparatus, a semiconductor material is manufactured as a foil 8 by flowing it down from a nozzle 4 at the lower end of the quartz container 3 and supplying it to the surface of a rapidly rotating quenching roll 5 for rapid solidification. The fine particles 10 to be incorporated into the base material of the foil 8 near the outside of the sealed container 1
A foil 8 is manufactured from the molten alloy 7 at the tip which is the other end of the particle (gas) introducing pipe 12 which is provided with the particle manufacturing apparatus 11 for manufacturing During the period until the flight, the particles are guided through the wall of the hermetically sealed container 1 to a lower position in the quartz container 3, for example, the bottom portion, and further, the fine particles are introduced into a portion located outside the hermetically sealed container 1. Pump 13 for pipe 12
The fine particles 10 produced by the fine particle production apparatus 11 are blown into the molten alloy 7 in the quartz container 3 through the fine particle introduction pipe 12 by operating the pressure pump 13.
The fine particles 10 are added and dispersed therein, and before the molten alloy 7 supplied to the surface of the quenching roll 5 through the nozzle 4 of the quartz container 3 is solidified to form the foil 8 as the semiconductor material, the fine particles 10 are formed. To take in.
Further, an exhaust gas pipe 14 equipped with a pressure adjusting valve 15 and an abatement device (exhaust gas treatment device) 16 is connected to the sealed container 1 so that the pressure in the sealed container 1 can be adjusted by operating the pressure adjusting valve 15. In addition, the exhaust gas generated in the sealed container 1 can be properly treated by the abatement device 16.

As the above-mentioned fine particle production apparatus 11, for example, a CVD type gas phase synthesis apparatus by an electric furnace heating method, a chemical flame (combustion) method, a plasma method, a laser method or the like is adopted. In FIG. 1, 17 is a gas supply pipe for supplying a reaction gas and a carrier gas into the fine particle production apparatus 11, and 18 is a flow meter provided in the gas supply pipe 17.

The fine particles 10 produced by the fine particle producing apparatus 11 and mixed in the molten alloy 7 are foil 8 as a semiconductor material having an electric conductivity of 10 to 1000 S / cm.
In order to increase the number of crystal grain boundaries, an oxide having a grain size of 1 μm or less, a density lower than that of a metal, and an electric conductivity of 0.01 S / cm or less, It is preferable to use a non-conductive substance such as a carbide or a nitride. Examples of the oxide include SiO ₂ and Al ₂ O _3.
And as the carbide, for example, SiC, Mo ₂ C
As the nitride, for example, Si ₃ N ₄ , AlN or the like can be used.

When the foil 8 as a semiconductor material is manufactured by using the foil manufacturing apparatus having the above-mentioned structure, it is basically carried out in the same manner as in the foil manufacturing apparatus shown in FIG.
Before producing the foil 8, in the molten alloy 7 in the quartz container 3,
The fine particles 10 made of the non-conductive substance manufactured by the fine particle manufacturing apparatus 11 are added in advance. That is, before the molten alloy 7 in the quartz container 3 is made to flow down from the nozzle 4 and supplied to the surface of the quenching roll 5, the pressure feed pump 13 is operated and the fine particles 1 produced by the fine particle production apparatus 11 are operated.
0 in a state of being placed in carrier gas 1
The fine particles 10 are dispersed in the molten alloy 7 by bubbling by blowing 2 through the bottom of the quartz container 3. Thus, when the molten alloy 7 in the quartz container 3 is supplied to the surface of the quenching roll 5 through the nozzle 4 and rapidly solidified, a foil 8 as a semiconductor material having an electric conductivity of 10 to 1000 S / cm is obtained. This obtained foil 8
Since the fine particles 10 are uniformly dispersed and included in the base material of No. 2, when the foil 8 is formed by the downstream sintering step, extrusion step or rolling step, the Seebeck coefficient and the electric conductivity values do not change. A high-performance thermoelectric semiconductor having a low thermal conductivity can be obtained.

In the above, the fine particles 1 in the molten alloy 7
Since the addition amount of 0 can be controlled, the value of thermal conductivity can be selected. Also, fine particles 10 other than oxides
When the foil 8 is manufactured by adding the above, the foil 8 is heat-treated before forming to oxidize only the fine particles 10 and reduce the base material. The crystal orientation can be improved by recrystallizing the crystal.

In FIG. 1, the tip of the fine particle introducing tube 12 is made to penetrate the lower end of the side wall of the quartz container 3 and the quartz container 3 is
Although the case where it is made to face the inner bottom is shown, it may be inserted into the bottom of the quartz container 3 from above the quartz container 3.

Next, FIG. 2 shows another embodiment of the present invention. In the same structure as that shown in FIG. 1, the fine particles 10 produced by the fine particle producing apparatus 11 are operated by the pressure feed pump 13. Instead of passing through the fine particle introduction pipe 12 to the bottom of the quartz container 3, the fine particle introduction pipe 1
The tip of 2 is made to face the position where the molten alloy 7 flows down on the quenching roll 5, and the fine particles 10 produced by the fine particle producing apparatus 11 are placed on the gas phase flow by the carrier gas supplied through the gas supply pipe 17 and The molten alloy 7 is introduced into the flow-down position, and the fine particles 10 are taken into the base material of the foil 8 when the molten alloy 7 is rapidly solidified on the quench roll 5.

In the case of the embodiment shown in FIG. 2, the fine particles 10 are introduced into the portion where the molten alloy 7 begins to solidify as the foil 8. However, at the time when the molten alloy 7 becomes the foil 8, in the base material of the foil 8. Since the fine particles 10 are taken in, the thermoelectric semiconductor having a small thermal conductivity is obtained by forming the foil 8 in the sintering step, the extrusion step or the rolling step as in the case of the embodiment of FIG. You can

In the embodiment of FIG. 2, the sealed container 1
The case where the fine particles 10 produced by the external fine particle production apparatus 11 is guided to the vicinity of the position where the molten alloy 7 flows onto the quenching roll 5 through the fine particle introduction pipe 12 is shown. The production apparatus 11 is arranged in the sealed container 1, and the vapor phase synthesis reaction part of the fine particle production apparatus 11 is positioned at a portion where the molten alloy 7 starts to solidify, and the fine particles 10 produced in-situ in the sealed container 1 are placed. The molten alloy 7
May be added to the portion that solidifies to form the foil 8.

Next, FIG. 3 shows still another embodiment of the present invention. In a structure similar to that shown by the solid line in FIG. 2, the tip of the fine particle introducing pipe 12 is placed on the quenching roll 5. Instead of allowing the molten alloy 7 to face the position where the molten alloy 7 flows down, the tip of the fine particle introduction tube 12 is made to face the portion where the molten alloy 7 solidifies and becomes the foil 8 in a high temperature state, and fly. The fine particles 10 are added to the surface of the foil 8.

In the case of the embodiment shown in FIG. 3, fine particles are not incorporated in the base material of the obtained foil 8, but by adding the fine particles 10 to the surface of the foil 8 in a high temperature state, The fine particles 10 can be uniformly dispersed and adhered to the surface of the foil 8, and when these foils 8 are formed in a sintering process, an extrusion process, or a rolling process, the fine particles 10 are incorporated into the base material crystal structure of the foil 8. It is possible to minimize an increase in electric resistance as a grain boundary impurity.

The present invention is not limited to the above-mentioned respective embodiments, and the respective embodiments may be appropriately combined and implemented, and in the embodiment, the fine particle manufacturing apparatus is used. 11 shows the case where the CVD method is adopted, the raw material is evaporated in an inert gas, the atoms of the generated raw material collide with the inert gas molecules and are decelerated, and the atoms collide and bond with each other to form the fine particles. So-called PVD
It is also possible to employ a vapor-phase synthesis apparatus of the system, and in the embodiment of FIG. 3, the fine particles 10 are attached to the surface of the obtained foil 8, but with respect to the obtained foil 8, If the plasma treatment is performed before the molding, the adhesion of the fine particles 10 can be improved, so that the molding temperature can be lowered. Further, in the embodiment of FIGS. 2 and 3, Although the case where the fine particles 10 are introduced into the surface portion of the foil 8 by the gas phase flow has been shown, instead of this, the surface of the fine particles 10 is charged with an electric charge to prevent agglomeration, and electromagnetic fields are used to transport the particles. In each of the embodiments,
Although the case of manufacturing the foil 8 as the semiconductor material has been described, the same applies to the case of manufacturing the foil other than the semiconductor material, and in this case, fine particles other than the non-conductive substance may be used, and other matters. Needless to say, various changes can be made without departing from the scope of the invention.

[0027]

As described above, according to the method for manufacturing a foil and the apparatus therefor of the present invention, the following excellent effects are exhibited. (1) A foil produced by melting an alloy raw material in a melting crucible, supplying the surface of a rotating quenching roll from the nozzle of the melting crucible to rapidly solidify the foil to produce a foil. In the manufacturing method and the apparatus thereof, fine particles are previously added and dispersed in the molten alloy in the molten crucible among the positions from the time when the foil is produced from the molten alloy to the flight, and the molten alloy is Since the fine particles are included before being solidified into a foil, it is possible to obtain a foil in which the fine particles are uniformly dispersed and incorporated in the base material. (2) A molten alloy obtained by melting the alloy raw material in the melting crucible, the foil is produced by rapidly solidifying by supplying to the surface of the quenching roll rotating from the nozzle of the melting crucible to rapidly solidify. In the manufacturing method and the apparatus thereof, in the position from the time when the foil is manufactured from the molten alloy to the flight, the fine particles are introduced into the portion where the molten alloy supplied from the nozzle to the surface of the quenching roll begins to solidify, By including the fine particles when the molten alloy is solidified, the same effect as in the case (1) can be obtained. (3) A molten alloy obtained by melting an alloy raw material in a melting crucible, a foil prepared by rapidly cooling and solidifying by supplying the molten alloy to the surface of a rapidly rotating quenching roll from the nozzle of the melting crucible. In the manufacturing method and apparatus thereof, so that the fine particles are included in the foil in the downstream molding step,
By adding the above-mentioned fine particles to the portion where the molten alloy is solidified and flies in a high temperature state as a foil among the positions from the production of the molten alloy to the flight of the foil, the fine particles are added to the surface of the foil. Since the particles can be uniformly dispersed and adhered, fine particles can be incorporated into the base material crystal structure of the foil by performing molding. (4) When the foil obtained by using the fine particles made of a non-conductive substance is a semiconductor material, a high performance thermoelectric semiconductor having a small thermal conductivity can be obtained by molding the foil.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an embodiment of a foil manufacturing apparatus of the present invention.

FIG. 2 is a schematic view showing another embodiment of the present invention.

FIG. 3 is a schematic diagram showing still another embodiment of the present invention.

FIG. 4 is a schematic view showing an example of a conventional foil manufacturing apparatus using a liquid quenching method.

[Explanation of symbols]

3 Quartz container (melting crucible) 4 nozzles 5 Quenching roll 6 alloy raw materials 7 Molten alloy 8 foil 10 fine particles 11 Fine particle manufacturing equipment 12 Particle introduction tube

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H01L 35/34 H01L 35/34 (72) Inventor Hiroki Yoshizawa 1 Shinshinarahara-cho, Isogo-ku, Yokohama-shi, Kanagawa Ishikawajima Harima Heavy Industries Co., Ltd. Machinery and plant development center F-term (reference) 4E004 DB02 DB20 TA07

Claims (12)

[Claims] 1. A foil is manufactured by supplying a molten alloy obtained by melting an alloy raw material in a melting crucible to the surface of a rotating quenching roll from a nozzle of the melting crucible to rapidly solidify the foil. In a method of manufacturing a foil,
A method for producing a foil, characterized in that fine particles are previously added and dispersed in the molten alloy in the melting crucible, and the fine particles are included before the molten alloy solidifies to form a foil. 2. A foil is manufactured by supplying a molten alloy obtained by melting an alloy raw material in a melting crucible to a surface of a rotating quenching roll from a nozzle of the melting crucible to rapidly solidify it. In a method of manufacturing a foil,
A method for producing a foil, characterized in that fine particles are introduced into a portion where the molten alloy supplied from the nozzle to the surface of the quenching roll begins to solidify, and the fine particles are included when the molten alloy solidifies. 3. A foil is produced by supplying a molten alloy obtained by melting an alloy raw material in a melting crucible to the surface of a rotating quenching roll from a nozzle of the melting crucible to rapidly solidify the foil. In a method of manufacturing a foil,
A method for producing a foil, characterized in that the above-mentioned particles are added to a portion where the molten alloy is solidified and flies in a high temperature state as the foil so that the foil contains the particles in a downstream forming step. 4. The method for producing a foil according to claim 1, 2 or 3, wherein the foil is a semiconductor material. 5. A semiconductor material having an electric conductivity of 10 to 100.
The method for producing a foil according to claim 4, wherein the foil is 0 S / cm. 6. The method for producing a foil according to claim 1, wherein the fine particles are fine particles made of a non-conductive substance. 7. The method for producing a foil according to claim 6, wherein the electrical conductivity of the fine particles made of a non-conductive substance is 0.01 S / cm or less. 8. The particle size of fine particles made of a non-conductive substance is 1
The method for producing a foil according to claim 6 or 7, wherein the thickness is not more than μm. 9. A foil is manufactured by supplying a molten alloy obtained by melting an alloy raw material in a melting crucible to a surface of a rotating quenching roll from a nozzle of the melting crucible to rapidly solidify the foil. In a foil manufacturing device,
The tip of a fine particle introducing pipe connected to the outlet of a fine particle producing apparatus for producing fine particles is arranged so that the fine particles are supplied at a position until the foil is produced from the molten alloy and flies. A foil manufacturing apparatus characterized by the above. 10. A foil is manufactured by supplying a molten alloy obtained by melting an alloy raw material in a melting crucible to the surface of a rotating quenching roll from a nozzle of the melting crucible to rapidly solidify the foil. In a certain foil production apparatus, the tip of the fine particle introduction pipe connected to the outlet of the fine particle production apparatus is arranged so as to face the inside of the melting crucible, and the fine particles produced by the fine particle production apparatus are melted in the melting crucible. An apparatus for producing a foil, characterized in that it has a structure in which it can be blown through the fine particle introduction tube. 11. A foil is manufactured by supplying a molten alloy obtained by melting an alloy raw material in a melting crucible to a surface of a rotating quenching roll from a nozzle of the melting crucible to rapidly solidify the foil. In a certain foil production apparatus, the tip of the fine particle introduction pipe connected to the outlet of the fine particle production apparatus is arranged so as to face the position where the molten alloy is supplied from the nozzle to the surface of the quenching roll, and produced by the fine particle production apparatus. An apparatus for producing a semiconductor material, characterized in that the fine particles thus obtained can be introduced into the portion where the molten alloy begins to solidify through the fine particle introducing pipe. 12. A foil is produced by supplying a molten alloy obtained by melting an alloy raw material in a melting crucible to the surface of a rapidly rotating quenching roll from a nozzle of the melting crucible to rapidly solidify the foil. In a certain foil manufacturing device, the tip of the particle introduction pipe connected to the outlet of the particle manufacturing device is placed so that it faces the part where the molten alloy solidifies and becomes a high temperature foil, and is manufactured by the particle manufacturing device. An apparatus for producing a foil, characterized in that it has a configuration in which the obtained fine particles can be added to the surface of the foil through the fine particle introducing pipe.