KR101193065B1 - Method for fabricating plate of amorphous metal by using Strip Casting process and the device thereof - Google Patents

Abstract

An object of the present invention is to provide a method and apparatus for producing a bulk amorphous alloy plate material or an alloy plate material mixed with an amorphous phase and a crystalline phase by using a strip casting process.

According to the present invention, a method of manufacturing an amorphous alloy plate using strip casting according to the present invention is to allow the molten metal supplied from the melting furnace to solidify while being pressed by a pair of casting rolls having different diameters, and then, among the casting rolls, The molten metal of the molten metal is cooled by sequentially contacting the metal strip passing through the casting roll by a plurality of cooling rolls arranged in the rear side of the casting roll having a diameter and paired with the casting roll having a long diameter, respectively. The cooling rate between the melting temperature (Tm) and the glass transition temperature (Tg) can be controlled by at least the number of the cooling rolls.

In addition, the apparatus for producing an amorphous alloy sheet includes a combination of the casting roll and the cooling roll described above.

Amorphous, Crystalline, Strip Casting, Sheet Material

Description

Method for fabricating plate of amorphous metal by using Strip Casting process and the device

1 is a conventional cooling curve graph, which is a schematic diagram for showing the change in the structure of the casting phase with the cooling rate.

2 is a schematic diagram of an apparatus for manufacturing an amorphous alloy sheet according to an embodiment of the present invention.

3 and 4 are TEM photographs showing the structure of the bulk amorphous alloy prepared by the method for producing an amorphous alloy sheet according to an embodiment of the present invention, Figure 3 shows a structure having an amorphous phase, Figure 4 Shows the organizational structure in which the crystalline phase is determined at the amorphous base.

<Description of the symbols for the main parts of the drawings>

1: melting furnace 2: molten metal supply nozzle

3, 4: casting roll 5: cooling roll

The present invention relates to a method for manufacturing an amorphous alloy sheet and a device thereof, and more particularly, to a method of manufacturing a bulk amorphous alloy sheet or an alloy plate mixed with an amorphous phase and a crystalline phase using a strip casting process, and It relates to a device therefor.

In general, amorphous alloys are alloys whose crystal structure is disordered and not in a crystalline state, such as water or glass, compared to conventional crystalline metals. Since they have no grain boundary, they have excellent electromagnetic properties. , 1 ~ 2% of free volume and super plasticity when heated, and have excellent strength and formability.

As a method of manufacturing such an amorphous alloy, conventionally, a method of manufacturing an amorphous metal thin film through vapor deposition or a thin amorphous metal strip or powder through quench solidification has been used, and recently, palladium (Pd) having excellent amorphous forming ability has been used. , Zirconium (Zr) alloy system is developed (US Patent No. 5735975, Japanese Patent Laid-Open Publication No. 1999-189855), the amorphous alloy manufacturing method by chill casting or die casting (US Patent No. 5896642, 6453977) This is being applied.

Also, Japanese Laid-Open Publication Nos. 2002-080949, 1998-102223, and 1999-256277 introduce iron (Fe) alloys having excellent amorphous forming ability. Iron-based amorphous alloys are provided by chill casting as in the previous palladium-zirconium alloy system because of the need for rapid cooling above &lt; RTI ID = 0.0 &gt;                         

However, the amorphous alloy manufacturing method as described above not only provides amorphous thin plates or powders having a thickness of µm to guarantee a fast cooling rate, but also the manufacturing process is discontinuous, so that a bulk amorphous alloy sheet having a thickness of 1 mm or more may be formed by a continuous process. There was a limit not to make it more efficient.

The present invention has been proposed to solve this problem, by using a strip casting (Strip Casting) to sufficiently cool the molten metal supplied to the glass transition temperature (Glass Transition Temperature (Tg)) of the alloy to the amorphous alloy plate material Another object of the present invention is to provide a method and apparatus for continuously producing an alloy plate material in which an amorphous phase and a crystalline phase are mixed.

In addition, an object of the present invention is to provide a method and apparatus for providing a bulk amorphous alloy sheet material having a thickness of 1 mm or more by strip casting, wherein the molten metal is amorphous when it is rolled to a thickness of 1 mm or more by a casting roll of a strip casting process. Since it is not produced, an additional cooling roll is installed at the rear of the casting roll to provide a configuration to cool the metal strip while being in contact with the metal strip passing through the casting roll.

In particular, in the present invention, when the molten metal supplied from the melting furnace is cooled while being pressurized using a continuously arranged double roll, each pair of rolls cannot be guaranteed in a space spaced between each of the continuously arranged double rolls. It provides a configuration that allows the metal strip to be in contact with the plurality of pair rolls to be rapidly cooled by minimizing the separation distance between the livers.

A method for producing an amorphous alloy sheet material using strip casting according to the present invention and apparatus for achieving the above object are arranged behind a pair of casting rolls having a different diameter and the casting roll having a shorter diameter among the casting rolls. Combining a plurality of cooling rolls rotating in pairs with the casting roll having a long diameter of a pair of casting rolls, the molten metal supplied from the melting furnace passes through the casting rolls and first solidified and then passes through the plurality of cooling rolls And it characterized in that the secondary cooling annually.

At this time, the casting roll performs the rolling and cooling function for the metal strip at the same time, and the cooling roll performs the function of cooling the metal strip by contact with the metal strip passing through, and the first solidified metal strip passing through the casting roll. Is rapidly cooled in the temperature range (ΔT = Tm-Tg) between the melting temperature (Tm) and the glass transition temperature (Tg) by a plurality of cooling rolls, thereby processing into a plate having an amorphous structure.

Hereinafter, a method and apparatus for manufacturing an amorphous alloy sheet according to the present invention having the above characteristics will be described in detail with reference to the accompanying drawings.

In general, the alloy melted by being overheated (Super Heating) above the melting temperature (Tm) is solidified at the melting temperature (Tm), and as shown in FIG. 1, the melting temperature (Tm) and the glass transition temperature (Tg). The metal structure is determined by the cooling rate in the temperature section ΔT therebetween. In other words, when the cooling rate is slow as in the cooling curve A, the metal strip has a crystalline structure. When the metal strip is rapidly cooled to the glass transition temperature (Tg) or lower as in the cooling curve C, the metal strip has an amorphous structure. When cooled at a moderate cooling rate as shown in cooling curve B, the metal strip has a mixed structure in which a crystalline phase is crystallized in an amorphous phase.

On the other hand, the strip casting process has a linear speed of 0.1 ~ 1m / sec and can produce a plate of 4 ~ 6mm thickness, at this process speed of the cooling rate is about several ℃ per second, thereby obtaining an amorphous structure. Therefore, in order to obtain a sheet alloy of amorphous structure by strip casting, it is necessary to consider the conditions for increasing the cooling rate.

R ∝ A / X ^m ∝ S ⁿ (Equation 1)

Here, R is the cooling rate, X is the thickness of the plate, S is the linear speed of the casting roll, A, m, n is a factor related to the moon delivery according to the design and plate thickness of the casting roll, the cooling rate (R) is Inversely proportional to thickness X and proportional to linear velocity S. Therefore, in order to increase the cooling rate during strip casting, the plate thickness (X) should be thinner and the linear velocity (S) should be increased.

At this time, the equation related to the speed of the strip casting is as follows.

t = L / S (Equation 2)

Where t is the contact time between the casting roll and the metal strip to be cooled, L is the length of the contact arc that the metal strip contacts along the circumference of the casting roll, and S is the linear speed of the casting roll. It is necessary to increase the linear velocity of the roll to 1m / sec or more, but since the length of the contact arc is constant, when the linear velocity of the casting roll increases, the metal strip exits the casting roll without being sufficiently cooled by the casting roll. It can be formed crystalline by being in the atmosphere.

Therefore, in the present invention, as shown in Figure 2, after the molten metal supplied from the melting furnace 1 through the molten metal supply nozzle (2) passes through the casting rolls (3, 4) having different diameters, casting In order to be cooled sequentially by a plurality of cooling rolls 5 arranged behind the roll, an amorphous alloy sheet material can be produced.

At this time, the lower casting roll (3) of the casting roll to have a long diameter in order to increase the cooling performance by the casting roll, the upper casting roll (4) so that a plurality of cooling rolls (5) can be installed in the rear. In addition, it was made compact to narrow the gap with the cooling roll (5) arranged in turn around the lower casting roll (3). In addition, the plurality of cooling rolls 5 are installed to be rotated in pairs with the lower casting roll (3), at least to have a diameter smaller than the upper casting roll (4). Unexplained reference numeral 6 is a guide for guiding the metal strip passing through the cooling roll (5).

In the amorphous alloy sheet manufacturing apparatus configured as described above, the melting temperature (Tm) of the metal strip passing through the casting rolls 3 and 4 by adjusting the number of the cooling rolls 5 arranged behind the upper casting roll 4. And the cooling rate between the glass transition temperature (Tg) can be adjusted. Look at one embodiment for checking the effects of the present invention.

Example

The alloy used is an iron (Fe) -based alloy, and in order to produce an amorphous alloy sheet having a thickness of 1 to 2 mm, the linear speed of the casting roll is controlled to 1 to 10 m / sec and paired with the lower casting roll 3. The installed cooling rolls 5 were adjusted to 2 to 3, and cooling water was supplied to the lower casting rolls 3. The alloy components used and the main data for these alloys are shown in Table 1 below.

TABLE 1

Alloy component Tx (K) Tg (K) Tm (K) ΔT (Tm-Tg) Trg (Tg / Tm) Fe ₆₃ Ni ₇ Zr ₆ Cr ₈ Si ₃ B ₁₀ W ₃ 859 795 1464 668 0.544

As can be seen in the above table, the metal strip of Fe ₆₃ Ni ₇ Zr ₆ Cr ₈ Si ₃ B ₁₀ W ₃ passed through the casting rolls (3, 4) and the cooling roll (5) according to the present embodiment DSC ( As measured by differential scanning calori meter (DTA) and differential theremal analysis, the crystallization temperature (Tx) was 859K, the glass transition temperature (Tg) was 795K, alloy melting temperature (Tm) was 1464K, and the cooling temperature section (ΔT). (Tm-Tg)) was 668K, and the simple glass transition temperature Trg (Tg / Tm) was 0.544. Therefore, the approximate cooling rate of this alloy could be predicted to be 1000 ℃ / sec or more by inferring the Trg value.

In the experiment, Fe ₆₃ Ni ₇ Zr ₆ Cr ₈ Si ₃ B ₁₀ W ₃ alloy was charged into the melting furnace (1), dissolved, and then supplied to the molten metal supply nozzle (2) through a supply pipe. It was injected between the two rolls of the casting roll (3, 4) to be cooled while being pressurized. At this time, by supplying the cooling water to the lower casting roll (3) of the casting roll to increase the cooling effect by the casting roll, a plurality of cooling the metal strip solidified between the casting rolls are installed along the circumference of the lower casting roll (3) It was allowed to further cool down by the roll 5.

At this time, the thickness of the alloy plate material is to be determined by the casting rolls (3, 4), the gap between the cooling roll (5) and the lower casting roll (3) is the alloy plate material that passes through the contact with the roll to cool Only adjusted as much as possible.

As a result of this experiment, by adjusting the amount of cooling water supplied to the lower casting (3), the linear velocity of the casting roll and the number of cooling rolls, the curve B and C of FIG. Cooling rate was obtained. 3 and 4 are photographs taken by TEM (Transmission Electron Microscopy) of the microstructure of the iron-based amorphous alloy sheet obtained according to the present experiment, and the amorphous alloy phase is remarkable as shown in FIG. 3 according to the control of each process variable. As shown in FIG. 4, the crystalline phases were crystallized in the amorphous phase matrix as shown in FIG. 4.

Embodiments as described above are described by way of example to help understanding of the present invention, it should be understood that various modifications are possible to the respective components, the method of manufacturing the amorphous alloy plate described in the present description and claims It is to be understood that in amorphous alloy plate material includes an alloy plate material in which an amorphous phase and a crystalline phase are mixed.

According to the method and apparatus for manufacturing an amorphous alloy plate using strip casting having the structure as described above, it is possible to continuously manufacture a bulk amorphous alloy plate having a thickness of 1mm or more using strip casting.

In particular, the upper casting rolls have a diameter smaller than the diameter of the lower casting rolls, and the cooling rolls having a diameter smaller than the upper casting rolls are arranged around the lower casting rolls, so that the spaced intervals between the rolls arranged annually are reduced. Thus, the cooling function of the hot metal strip through the cooling roll is improved.

Claims (4)

In the method of manufacturing a bulk amorphous alloy sheet material having a thickness of 1mm or more using strip casting, Solidifying the molten metal supplied from the melting furnace while being pressed by the lower casting roll having a long diameter and the upper casting roll having a short diameter having a linear speed of 1 to 10 m / sec; The metal strips passing through the casting rolls are sequentially contacted by a plurality of cooling rolls having a diameter smaller than that of the upper casting rolls, which are arranged on the rear side of the upper casting rolls and are paired with the lower casting rolls, respectively. While being cooled while controlling the number of cooling rolls, the cooling rate of the metal strip is controlled between the melting temperature (Tm) and the glass transition temperature (Tg) of the molten metal to form an amorphous phase on the metal strip. Method of manufacturing plate. The method of claim 1, The thickness of the amorphous alloy sheet produced by passing through the casting rolls and the cooling rolls, characterized in that to be determined by the pair of casting rolls. In the apparatus for producing a bulk amorphous alloy sheet material having a thickness of 1mm or more using strip casting, A pair of casting rolls having an upper casting roll having a short diameter and a lower casting roll having a long diameter, and having a linear speed of 1 to 10 m / sec, for primary cooling while pressurizing the molten metal supplied from the melting furnace; , The casting rolls are arranged along the circumference of the lower casting rolls at the rear side of the upper casting rolls, and are provided in plurality in pairs with the lower casting rolls, each having a smaller diameter than the upper casting rolls, and passing through the casting rolls. The high temperature metal strips are cooled as they are sequentially contacted, but the cooling rate of the metal strips is controlled between the melting temperature (Tm) and the glass transition temperature (Tg) of the molten metal to control the number of installations so that an amorphous phase is formed on the metal strips. Apparatus for producing an amorphous alloy sheet comprising a cooling roll provided to enable. The method of claim 3, wherein Apparatus for producing an amorphous alloy sheet material, characterized in that the diameter of the cooling roll is not larger than the diameter of the short diameter cast roll of the pair of casting rolls.

Images