JP2017121635A - Amorphous alloy foil strip manufacturing apparatus and amorphous alloy foil strip manufacturing method using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an amorphous alloy foil strip manufacturing apparatus which controls surface unevenness of amorphous foil strips, and to provide an amorphous alloy foil strip manufacturing method using the manufacturing apparatus.SOLUTION: An amorphous alloy foil strip manufacturing apparatus includes: a cooling roll 5; driving means which rotates the cooling roll 5; first supply means 3 which supplies molten alloy to an outer peripheral surface of the cooling roll 5; and second supply means 2 which supplies a pressure to the molten alloy.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an amorphous alloy foil strip manufacturing apparatus and a method for manufacturing an amorphous alloy foil strip using the same.

  Normally, a metal has a crystal structure in which atoms are arranged in an orderly manner, but when rapidly cooled as a liquid melted at a high temperature, it becomes a solid having a liquid structure. An amorphous alloy in which the crystals are randomly packed is called an amorphous alloy.

  Amorphous alloys are excellent in electrical properties such as high strength and low magnetic loss, but advanced technology is required for processing. The most common method for producing amorphous alloys is a single roll liquid quenching method. In the single roll liquid quenching method, molten metal (hereinafter referred to as molten alloy) is brought into contact with the outer peripheral surface of the roll while rotating a metal or alloy roll (drum) having high thermal conductivity at a high speed. Is rapidly cooled to solidify in a foil strip shape. In the technique of manufacturing a foil strip directly from such a molten metal, how to make the thickness and surface properties of the foil strip uniform is an important issue.

  In recent years, it has been studied to use an amorphous alloy with little magnetic loss for the iron core of a transformer or a motor. Since amorphous foil strips used as iron core materials are used by being laminated, the superiority or inferiority of the surface properties of each one affects the characteristics of the transformer and the motor as a whole.

  The following causes can be considered for the deterioration of the surface quality of the amorphous foil strip. As a method of forming an amorphous foil strip, there is a method of flowing a molten amorphous material on the surface of a cooling roll rotating at a high speed. At this time, a molten metal pool (hereinafter referred to as paddle) on the cooling roll. And the surface of the cooling roll (boundary layer), air is trapped inside the foil strip solidifying on the roll as it is, and surface irregularities are formed in the amorphous foil strip. By winding an amorphous foil strip having surface irregularities to make an iron core, the iron core may be enlarged.

  The mechanism of air entering between the amorphous foil strips is that the paddle is vibrated by some external force, changing the wetting angle of the surface formed by the roll surface and paddle, and the air entrainment part (air pocket) where air can easily enter This can be done periodically in the boundary layer.

As a result, a fish scale-like pattern (fish scale) corresponding to this cycle is formed in the manufactured foil strip, and the uniformity of the surface property of the foil strip is lowered. Further, when the uniformity of the surface property of the foil strip being solidified is not good, the heat of the foil strip is not efficiently conducted to the roll, and the foil strip is not rapidly cooled, so that it becomes more difficult to be amorphous.
Many studies have been conducted on paddle vibration, and it has been reported that there are two types of vibration. One is due to the kinematic cause (capillary wave) that the surface film of the paddle vibrates when the air collides with the paddle, and the other is that the air hits the paddle and the molten metal This is due to a chemical reactive cause (Marangoni effect) in which the surface is oxidized non-uniformly and vibrates as a result of non-uniform surface tension.

  On the other hand, prevention of uniformity of the foil strip surface properties due to these causes has been studied conventionally, and the air impinging on the paddle is diluted or a low-density inert gas or reducing gas is used instead of air. A number of such methods are disclosed in the following patent documents.

Japanese Patent Laid-Open No. 51-109221 JP 59-209457 A JP 60-37249 A Japanese Patent Laid-Open No. 6-292950 and Japanese Patent Laid-Open No. 51-109221 disclose a method for producing an improved alloy filament in a vacuum chamber. However, this manufacturing method is effective when a small amount of foil strip is manufactured, but there is a problem that equipment cost and running cost are high for mass production.

  Japanese Laid-Open Patent Publication No. 59-209457 proposes to improve the facility problem of the method described in Japanese Laid-Open Patent Publication No. 51-109221 and to use a low-density and high-temperature inert gas. . However, inert gases such as low-density helium, krypton, and xenon that are effective in this method are very expensive and still have problems in terms of running cost.

  Further, Japanese Patent Application Laid-Open No. 60-37249 discloses that when manufacturing a foil strip in an exothermic reducing atmosphere, inexpensive carbon monoxide is burned into a low density reducing gas, and the running cost is high. The problem of being was solved. However, carbon monoxide has safety issues.

As a method for solving these problems, there is a foil strip manufacturing apparatus described in JP-A-6-292950, and a method has been proposed in which CO ₂ gas is sprayed in the vicinity of the paddle to greatly improve the surface properties of the foil strip. However, this method also has another problem that a good surface roughness cannot be stably obtained when the foil strip has a width of 100 mm or more.

  In view of the various problems described above, the present invention provides an apparatus for manufacturing an amorphous alloy foil strip that can control surface irregularities of the amorphous foil strip, and a method for manufacturing an amorphous alloy foil strip using the manufacturing apparatus. The purpose is to do.

  The amorphous alloy foil strip manufacturing apparatus according to the present invention includes a cooling roll 5, a driving means for rotating the cooling roll 5, a first supply means 3 for supplying molten alloy to the outer peripheral surface of the cooling roll 5, and an alloy It has the 2nd supply means 2 which supplies a pressure with respect to a molten metal, It is characterized by the above-mentioned.

  According to the present invention, it is possible to control the surface unevenness of the amorphous foil strip.

It is a perspective view which shows the manufacturing apparatus of the amorphous alloy foil strip which concerns on one Embodiment of this invention. It is an enlarged view of the nozzle part in FIG. It is a figure which shows the morphological alloy foil strip surface observation profile in three dimensions. It is the figure which showed the time-dependent change of the temperature of the foil strip containing an unsolidified fluid, and the time-dependent change of the temperature of the roll surface.

  Embodiments of the present invention will be described below with reference to the drawings. The following are merely examples of implementation and are not intended to limit the content of the invention to the following specific embodiments.

  As shown in FIG. 1, the amorphous alloy foil strip manufacturing apparatus 1 according to this embodiment manufactures an amorphous alloy foil strip 4.

  The manufacturing apparatus 1 is provided with a water cooling roll 5. The water-cooled roll 5 is made of a metal or alloy having high thermal conductivity, and is made of, for example, copper or a copper alloy. A water flow pipe 6 is provided at one end of the water-cooled roll 5, and cooling water is supplied to the inside through the water-flow pipe 6. Further, a motor for rotating the water-cooled roll 5 is connected to the other end of the water-cooled roll 5. The cooling water is introduced into the water channel from one end of the water-cooling roll 5 through the water conduit 6, and is discharged through the water conduit 6 after flowing through the water channel. The discharged cooling water is cooled again by a cooling means (not shown) and injected into the water conduit 6.

  In addition, in this invention, it is not limited to the above-mentioned water-cooled roll, For example, it is also possible to use the structure which cools the surface temperature of a roll by providing a fan in a roll and taking in the air cooled in the roll.

As shown in FIG. 2, above the water-cooled roll 5, a supply means 3 for supplying molten alloy as a material of the amorphous alloy foil strip 4 and a nonmetallic liquid (for example, water) immediately after discharging the molten alloy. Or the supply means 2 for discharging gas (for example, air) toward the surface of a molten alloy is provided.
Furthermore, the supply means 3 has a nozzle 3a that discharges the molten alloy toward the outer peripheral surface of the water-cooled roll 5, and the supply means 2 supplies a nonmetallic liquid (for example, water) or gas (for example, air) to the molten alloy. It has a nozzle 2a that discharges toward the surface. The discharge ports of the nozzle 3 a and the nozzle 2 a face the water-cooled roll 5, and a slight gap is formed between the outer peripheral surface of the water-cooled roll 5 and the material surface of the amorphous alloy foil strip 4.

  The nozzle 3a and the nozzle 2a shown in FIG. 2 have a shape in which two slits are arranged, but a nozzle having three or more slits may be used. For example, a plurality of slits of the nozzle 2a may be provided. The direction in which the slit 3 a and the slit 2 a extend is preferably the same as the axial direction of the water-cooled roll 5.

  The distance between the slit 3a and the slit 2a is set so that the molten alloy 3 discharged from the slit 3a receives pressure from the slit 2a until the molten metal 3 is cooled by the water-cooled roll 5 and reaches the glass transition temperature Tg. The In other words, the distance between the slit 3a and the slit 2a is set so that the molten alloy 3 discharged from the slit 3a receives pressure from the slit 2a until it becomes a completely metallic solid from the Newtonian viscous state that is a supercooled liquid. Is done. In this embodiment, the supply means 2 and the supply means 3 are integrally formed, but can be formed separately.

  Next, the manufacturing method of the amorphous alloy foil strip 4 according to the present embodiment will be described.

  First, the water-cooled roll 5 is rotated at a high speed while circulating the cooling water through the water pipe 6 into the water-cooled roll 5. In this state, the molten alloy is injected into the nozzle 3a, and the molten alloy is discharged toward the water-cooled roll 5 through the nozzle 3a, and is brought into contact with the outer peripheral surface of the water-cooled roll 5. As a result, a paddle (water pool) is formed between the nozzle 3 a and the water-cooled roll 5.

  Of the molten alloy forming the paddle, the portion in contact with the water-cooled roll 5 is cooled to increase the viscosity, and is pulled out of the paddle by the rotation of the water-cooled roll 5. The molten alloy drawn out from the paddle is dragged to the outer peripheral surface of the water-cooled roll 5 and moved in the rotation direction of the water-cooled roll 5, and is cooled by the water-cooled roll 5 to become a Newtonian viscous metal fluid that is a supercooled liquid. . Next, the amorphous alloy foil strip 4 is formed by solidifying from a viscous metal fluid and becoming a temperature lower than the glass transition point Tg.

  For example, when one nozzle 3a and two nozzles 2a are formed, first, the molten metal paddle discharged from the nozzle 3a is cooled by the water-cooling roll 5 and is a supercooled liquid Newtonian viscous metal fluid. It becomes. Immediately thereafter, pressure is supplied from the nozzle 2a toward the surface of the metal fluid in the Newtonian viscous state. Specifically, a nonmetallic liquid (for example, water) or a gas (for example, air) is discharged toward the surface of the metal fluid material in a Newtonian viscous state that is a supercooled liquid. Thereby, a completely solid amorphous alloy foil strip 4 is formed.

  Before the high-viscosity fluid drawn from the molten alloy paddle reaches the glass transition point Tg, a nonmetallic liquid (for example, water) or gas (for example, air) supplied from the nozzle 2a is discharged onto the surface of the high-viscosity fluid. By doing so, the unevenness of the surface property of the high clay fluid can be suppressed, so that the uniformity of the surface property of the amorphous foil strip can be improved.

  In the conventional manufacturing process, as shown in the surface observation profile of the amorphous alloy foil strip in FIG. 3, the wetting angle of the surface formed by the roll surface and the paddle changes due to the vibration of the air layer, etc. A fish scale-like pattern (fish scale) was formed in which the pocket) coincided with the period of the boundary layer, and the uniformity of the surface property of the amorphous foil strip was lowered.

  The technique of this embodiment makes it possible to suppress changes in the wetting angle of the surface formed by the roll surface and the paddle due to vibration of the air layer and the like, and the periodic boundary of the air entrainment part (air pocket) Formation of the layer can be prevented. Thereby, the uniformity of the surface property of the amorphous foil strip can be improved.

  On the other hand, the heat transmitted from the molten alloy 3 to the water-cooled roll 5 is transmitted to the outer peripheral portion of the water-cooled roll 5 and is transmitted to the cooling water flowing through the water-cooled roll 5. The heat transmitted to the cooling water is discharged to the outside of the water cooling roll 5 together with the cooling water. That is, the heat of the molten alloy 3 is transmitted from the molten alloy 3 to the water-cooled roll 5 and further transmitted to the cooling water and discharged.

  The reason why unevenness on the surface of the amorphous alloy foil strip 4 can be controlled by discharging a nonmetallic liquid or gas toward the surface of the metal fluid material in a Newtonian viscous state that is a supercooled liquid will be described below. The right axis of FIG. 4 schematically shows the time change of the temperature of the amorphous alloy foil strip containing the unsolidified fluid (corresponding to the distance in the downstream direction from the paddle), and the left axis of FIG. 4 shows the temperature change of the cooling roll surface. Is schematically shown.

  The curve in FIG. 4 represents the case where a thin amorphous alloy foil strip (for example, 25 μm) is manufactured with a roll having a small thickness (conventional method, for example, 10 mm). Moreover, the measurement position of the roll surface temperature shown in FIG. 4 is an upstream side of the paddle of the molten alloy 3, for example, a position 20 cm from the paddle.

  As shown in FIG. 4, the initial roll surface temperature rises rapidly, and then the rate of temperature rise decreases but continues to rise linearly with a constant gradient. In addition, in the case of the thin cooling roll, the microscopic structure of the formed amorphous foil strip is amorphous (amorphous) up to the roll surface temperature T1, but when it exceeds that, crystallization starts.

  Therefore, by discharging non-metallic liquid (for example, water) or gas (for example, air) to the high-viscosity fluid drawn from the paddle of the molten alloy 3 until the roll surface temperature T1, the high clay fluid is discharged. Suppress surface irregularities.

  Thereafter, when the time further elapses, a paddle break occurs when the roll surface temperature is T2, and the foil strip is not formed thereafter. The surface temperature of the cooling roll where crystallization starts is T1, and the surface temperature of the roll where the paddle break occurs is T2.

  Conventional iron cores for transformers and motors laminated with amorphous alloy foil strips have the problem of increasing the size of the iron core due to the presence of irregularities on the surface of each foil strip.

  On the other hand, since the present invention can control the surface properties of the amorphous alloy foil strip in the process of solidifying the amorphous alloy foil strip, it is possible to suppress irregularities on the surface of the amorphous alloy foil strip. Can be prevented. In addition, the improvement of the surface texture quality of the foil strip can increase the space factor within a certain volume of the transformer and motor, so that the transformer and motor can be miniaturized. Furthermore, by suppressing the irregularities on the surface of the amorphous alloy foil strip, heat transfer is performed smoothly, the cooling rate is improved, and the loss of electrical characteristics can be further reduced.

  DESCRIPTION OF SYMBOLS 1 ... Amorphous alloy foil strip manufacturing apparatus, 2 ... Supply means, 2a ... Nozzle, 3 ... Supply means, 3a ... Nozzle, 4 ... Amorphous alloy foil strip, 5 ... Water cooling roll, 6 ... water pipe

Claims (6)

  A cooling roll; drive means for rotating the cooling roll; first supply means for supplying molten alloy to the outer peripheral surface of the cooling roll; and second supply means for supplying pressure to the molten metal. An apparatus for producing an amorphous alloy foil strip, comprising:   2. The amorphous alloy foil strip manufacturing apparatus according to claim 1, wherein the first supply unit and the second supply unit include an opening provided in a direction coaxial with a rotation axis of the cooling roll.   2. The amorphous alloy foil strip manufacturing apparatus according to claim 1, wherein the second supply means discharges a non-metallic liquid to the molten metal.   2. The amorphous alloy foil strip manufacturing apparatus according to claim 1, wherein the second supply means discharges gas to the molten metal.   2. The amorphous alloy foil strip manufacturing apparatus according to claim 1, wherein the cooling roll is a water cooling roll, and further includes means for cooling the cooling water of the water cooling roll. Using the amorphous alloy foil strip manufacturing apparatus according to claim 1,
Cooling the alloy melt on the outer peripheral surface of the cooling roll to form an amorphous alloy layer;
While rotating the cooling roll, before the amorphous alloy layer solidifies, pressure is supplied to the amorphous alloy layer,
A method for producing an amorphous alloy foil strip.

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