JP3100798B2 - Quenched metal strip manufacturing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a quenched metal strip manufacturing apparatus for manufacturing a metal strip having a small thickness and a smooth surface.

[0002]

2. Description of the Related Art In order to cope with the recent increase in the frequency of electronic devices, research has been conducted on the ultra-thin amorphous alloy ribbon using a single roll method. It is intended to reduce it. Since the eddy current loss, which is one of the components of the iron loss, decreases as the plate thickness decreases, the ultra-thin ribbon is effective for reducing the iron loss in a high frequency range.

In order to obtain an ultrathin amorphous alloy ribbon, it is necessary to reduce air pockets and to form a stable pool (hereinafter referred to as "paddle").
The air pocket is a space created by expansion of gas trapped between the paddle and the cooling roll during casting. This part reduces heat transfer, so the opposite surface,
That is, it appears as a dent on the free surface, and reduces the smoothness of the surface. When the thickness of the ribbon is large, the influence is relatively small. However, when the thickness is small, the influence is large, and the number of pinholes (holes) is formed. Thin ribbons with poor smoothness and many air pockets degrade the soft magnetic properties, thus offsetting the effect of reducing the thickness.

The following proposals have been made as measures for increasing the smoothness and reducing the air pockets.
That is, Yagi and Sawa et al. Disclose a method for producing an ultra-thin amorphous alloy, in which the single-roll method is carried out in a reduced-pressure atmosphere (JP-A-63-2153).
No. 48, Japanese Unexamined Patent Publication No. Hei 3-90547, and the 26th meeting of the Society for the Promotion of Amorphous Materials of the Japan Society for the Promotion of Science, page 26. Here, the single roll method is a method of manufacturing a metal ribbon using a single roll as a cooling body, and for example, there is a planar flow casting method (hereinafter, referred to as a “PFC method”) using a slit-shaped nozzle. . In the PFC method, the gap between the roll and the nozzle is limited to 0.03 to 1 mm, and the paddle is supported by the roll and the nozzle, whereby a thin ribbon having a uniform thickness can be obtained.

In the production performed by Yagi and Sawa et al., By reducing the atmosphere to a vacuum or reduced pressure, the amount of gas trapped between the quenched surface of the roll and the molten metal is reduced, and the plate thickness is reduced and the surface is smoothed. A simple amorphous alloy ribbon can be obtained. However, manufacturing in such a reduced-pressure atmosphere requires large-scale equipment such as a vacuum vessel or a reduced-pressure vessel, and has a problem in economics. Furthermore, since the production is carried out in a container, it is difficult to take out the ribbon and the work efficiency is poor.

As a method for controlling the entrained gas without reducing the pressure, a method of blowing a low-density gas by Howard Horst Lieberman is disclosed. This method (Japanese Patent Publication No. 2-18665) is characterized in that an inert gas (N ₂ , He, Ne, Ar, Kr, Xe and a mixture thereof) whose density is reduced by heating is blown to a quenching region. This is a method for producing an amorphous alloy ribbon having a smooth surface. In other words, by blowing a gas that has been expanded and reduced in density by heating in advance, the aim is to suppress the expansion accompanying the temperature rise of the gas trapped between the quenched surface of the roll and the molten metal. In this case, a special decompression vessel is not required, but a heating means for reducing the density of the gas is required, and there is a problem of economical efficiency in increasing the flow rate of the blowing gas. Further, the stability of the paddle is poor due to the blowing gas.

The following method has also been proposed as a measure for suppressing the entrained gas. It is similar to Wen-Kuan Wang et al.
rnational Jornal of Rapid Solidification, 6 (1991) 28
5-295). In the PFC method, they succeeded in heating the gas upstream of the paddle with arc plasma to produce a ribbon having a smooth surface without air pockets. However, since the roll surface is extremely rough due to plasma formation, it is not suitable for casting for a long time, and it is considered that it is difficult to obtain quenching conditions that can produce amorphous for a long time stably because the roll surface is considered to be hot. Seem.

On the other hand, in order to form a stable paddle,
A method of flowing e-gas has been proposed by Davor Pavuna (Jornal of Materials Science, 16 (1981) 2419-2433).
Pavuna uses the chill block melt spinning method (hereinafter
In the “CBMS method”, He is sprayed on the paddle to stabilize the paddle. Note that the CBMS method is one of the single roll methods using a single-hole nozzle,
The feature is that the interval between the roll and the nozzle is not limited to a narrow range. In the CBMS method, since the molten metal jet that has passed through the round hole nozzle collides with the roll and spreads, the paddle is unstable. Pavuna sprayed He gas to stabilize this unstable paddle. But Pavu
Since the method of na is not intended for ultra-thin, the conditions for spraying He gas are not suitable for the ultra-thin intended by the present inventors. In Pavuna's experiment, the obtained ribbon was the thinnest and had an average thickness of 24.6 μm. Regarding the smoothness, the vibration in the thickness direction was 4 μm (page 2430, left column, line 14).
However, it is completely insufficient in terms of a very thin amorphous amorphous surface.

[0009]

DISCLOSURE OF THE INVENTION The present invention provides an apparatus for producing a thin ribbon having a smooth surface or an ultra-thin ribbon in a PFC method at low cost and without the need for a pressure reducing mechanism or a gas heating device. The purpose is to provide.

[0010]

SUMMARY OF THE INVENTION The present invention relates to a quenched metal ribbon manufacturing apparatus using a single cooling roll, comprising the following components (1) to (4). . A crucible having a slit opening on the bottom surface for ejecting a molten alloy having a slit width of 0.2 to 0.4 mm. A He gas ejection port installed close to the upstream side of the opening; The position of the gas ejection port is 2 to 40 from the slit opening.
mm, 0.1 to 10 mm on the roll surface. The shape of the gas outlet is slit or porous, and has a length of 0.8 or more times the length 1 measured in the cooling roll width direction of the molten metal nozzle. A gas ejection port arranged so that the direction of gas ejection has an inclination of 10 to 90 degrees with respect to the tangent of the roll surface to which the molten metal contacts.

Hereinafter, the present invention will be described in detail. FIG. 1 shows a main part of a quenched metal ribbon manufacturing apparatus according to the present invention.
The alloy is filled in the crucible (not shown), the alloy is melted by heating means (not shown), and the molten metal 4 is jetted from the molten metal nozzle 2 on the bottom of the crucible. The molten metal is cooled by the cooling roll 1 to obtain a ribbon. Up to this point, the process is the same as the ordinary PFC method, but the apparatus of the present invention is characterized in that the gas nozzle 3 is installed on the upstream side at this time and a mechanism for flowing a small amount of room temperature He gas is provided.

The gas outlet, which is the most important feature of the present invention,
The reason for installing at a predetermined position on the upstream side of the slit opening will be described. As described above, in the single roll method, it is necessary to reduce air pockets as a condition for obtaining a thin strip having a small thickness and a smooth surface. In this case, formation of a stable paddle is greatly involved.

The turbulence of the paddle and the formation of air pockets due to the turbulence are considered to be due to the following effects. Gas paddle upstream has a distribution constant rate, O ₂ and N ₂ of adsorbed atmospheric in this case roll surface, dive between the paddle and the roll multiplied by the vibrations of the paddles, form an air pocket I do. In order to stabilize the paddle, it is necessary to control the gas flow upstream and near the paddle and near the roll surface. So, He, upstream of the paddle
It has been found that the formation of air pockets can be remarkably suppressed by adopting a means for blowing gas onto the roll surface to suppress the gas flow in the upstream region, and by forming a stable flow of He gas near the paddle. This has led to the completion of the apparatus of the present invention, which is capable of simultaneously suppressing paddle vibration and reducing the pressure under which gas is introduced by replacing O ₂ and N ₂ which have been adsorbed by He gas with He gas. .

Hereinafter, the relative position and shape of the gas ejection port and the direction of the gas ejection will be described. First, the relative position of the ejection port will be described. The distance b between the gas ejection port and the slit opening shown in FIG. 1 is arranged in the range of 2 to 40 mm. By setting the position of the gas ejection port in this range, He creates a laminar flow near the paddle on the quenching surface of the roll, and it is possible to minimize the entrainment of gas into the paddle. The above distance b
If it is less than 2 mm, the gas flow tends to be turbulent, the paddle becomes unstable, and the entrainment of gas increases. In addition, the nozzle cools and nozzle clogging easily occurs. If the distance b is set to 40 mm or more, He having a small density scatters into the atmosphere before reaching the vicinity of the paddle, and the effect of suppressing the formation of air pockets is lost.

The distance c from the roll surface is 0.1 to 10 mm
And If the distance c is 0.1 mm or less, the gas flow tends to be turbulent. If the thickness is 10 mm or more, the amount of He reaching the roll surface decreases, and as a result, the amount of He reaching the paddle decreases due to the movement of the roll surface due to the viscosity of He.

Next, the shape of the gas ejection port will be described.
The shape of the gas outlet may be either slit or porous. Examples of the shape of the gas ejection port are shown in FIGS. In the case of a porous structure, it is desirable to arrange the holes so that no break is formed in the gas flow. However, since the entire paddle is surrounded by the He atmosphere, the length of the gas ejection port (e in FIG. 3) is set to be 0.1 mm with respect to the length l (d in FIG. 3) measured in the cooling roll width direction of the molten metal nozzle. Must be at least eight times longer.

Further, the direction of gas ejection will be described.
The inclination θ of the gas ejection direction is set to 10 to 90 degrees with reference to the tangent of the roll surface where the ejection axis of the molten metal contacts. By controlling the direction of gas ejection in this range, He easily forms a laminar flow, and an effect of suppressing the generation of air pockets can be obtained. If the inclination θ measured downward with respect to the horizontal is smaller than 10 degrees, the velocity component of the gas flow perpendicular to the roll surface becomes small, and the replacement of He and air becomes insufficient. Therefore, it becomes difficult to form a laminar flow of He gas near the paddle.
When the inclination θ is larger than 90 degrees, the gas flow becomes a flow in a direction opposite to the roll moving direction, and turbulence is likely to occur.

The bottom surface of the He gas ejection nozzle is desirably parallel to the roll surface. The reason is that the sprayed He gas is not easily scattered. As described above, in order to reduce the air pocket, it is important to form a stable He gas flow near the paddle, and for that purpose, it is necessary to prevent light He gas from scattering upward.
If the bottom surface of the gas ejection nozzle is open to the paddle side or vice versa, it is He
The probability that the gas scatters upward increases, and a sufficient effect cannot be obtained.

As a structure for enhancing the He gas scattering prevention effect, for example, one of the gas ejection nozzles is extended in the direction of the molten metal nozzle as shown in FIG. 4A, or the upstream width of the molten metal nozzle as shown in FIG. 4B. The effect can be further enhanced by expanding.

Next, the reason why the numerical value of the slit width at the bottom of the crucible from which the molten metal is ejected is limited will be described. In the single roll method, when aiming to obtain a flat or ultra-thin ribbon, it is essential to form a stable paddle. If the slit width a shown in FIG. 1 is smaller than 0.2 mm, the slit is clogged, and stable supply of the molten metal cannot be obtained for a long time. On the other hand, if it is wider than 0.4 mm, the supply of the molten metal becomes excessive and a thin plate cannot be obtained. Therefore, in the present invention, the width of the slit is set to 0.2 to 0.4.
It is specified as mm.

As described above, by using the quenched metal ribbon manufacturing apparatus provided with the gas outlet for flowing the He gas of which the width of the slit opening is controlled and the shape and the position of which are controlled, the thickness is extremely thin. In addition, an amorphous alloy ribbon having a smooth surface can be manufactured.

The master alloy is made of Fe, Co, Ni, Cr, Sn, Mo, Si,
B, C, etc. are blended in a predetermined composition range and are melted. The quenching roll is made of Cu, Cu-Cr,
Made of Cu-B, Fe alloy, etc., Ni, Cr,
Cu or the like may be plated. The nozzle is made of quartz, alumina (Al ₂ O ₃ ), Si ₃ N ₄ , ZrB ₂ C, etc.
A single slit nozzle is desirable. The single nozzle is a nozzle having one elongated slit-like opening having a width of 0.1 to 1.0 mm measured in the roll rotation direction. The gas pressure for injecting the molten metal is 0.05 to 1 kg / cm ^{2 in} gauge pressure, the gap between the nozzle and the roll quenching surface is 1 mm or less, and the roll peripheral speed is 1
0 to 40 m / sec is desirable.

[0023]

EXAMPLES The present invention will be further described below with reference to examples. Embodiment 1 The apparatus of the embodiment has the following structure. That is, there is a crucible made of quartz for filling and melting the mother alloy, and a nozzle for jetting molten metal made of quartz is connected to the bottom of the crucible. The melt nozzle has a single slit, and the opening has a length of 5 mm and a width of 0.2 to 0.3 mm. The longitudinal direction of the slit is set so as to be perpendicular to the moving direction of the roll. The nozzle bottom is installed so as to be parallel to the roll surface. The cooling roll is made of Cu. The gas ejection port, which is a feature of the present invention, is located on the upstream side of the molten metal nozzle, 20 mm upstream from the slit opening, and at a distance of 5 mm from the roll surface.
mm. The shape of the gas outlet is a single slit, and the opening is 5 mm wide × 30 mm long. The slit has its longitudinal direction aligned parallel to the longitudinal direction of the molten metal nozzle.

The direction of gas ejection is about 5 to the roll surface.
At an angle of 0 degrees, the bottom surface of the opening is substantially parallel to the roll surface. The gas outlet has a structure in which room temperature He gas can flow during casting. The material is quartz.

Next, casting performed using the above-described apparatus will be described. After melting a mother alloy having a composition of Co ₆₉ Fe ₄ Si ₁₆ B ₉ Mo ₂ , 500 g was subjected to high frequency melting.
The melted mother alloy is passed through the molten metal nozzle and the peripheral speed is 24 m / se
The film was jetted onto a rotating roll at c and quenched to produce an amorphous ribbon. He flow rate is 5 l / min (3.3 l
/ Min · cm ² ).

By changing the ejection pressure and slit width,
Amorphous ribbons of various thickness were produced. The plate thickness was measured by the following two methods. Photograph of the cross section of the ribbon with an optical microscope, and the thickness t of the contour with no air pocket
a and the average thickness tb obtained from the weight, length, width and density of the ribbon. Tb is ta due to the presence of air pocket
Smaller. That is, it can be said that the closer the tb is to the ta, the smaller the number of air pockets and the smoother the surface. Table 1 shows the profile thickness ta and the average thickness t of the ribbon produced by the apparatus of the present invention.
b, smoothness tb / ta and the number n of pinholes per unit length are shown. Table 1 also shows, as comparative examples, a ribbon that was sprayed with Ar instead of He and a ribbon that was fabricated without spraying He (other manufacturing conditions were the same). By using the apparatus of the present invention, 12 μm
It can be seen that in the following ultrathin regions, a thin ribbon with a smooth surface can be effectively obtained. Next, the outer diameter of the obtained ribbon was 18 mm,
A toroidal wound core having an inner diameter of 12 mm was produced. Weight is
3.5-4.5 g. This wound iron core is 1
While applying a magnetic field of 0 Oe in the circumferential direction of the toroid, 45
It was kept at 0 ° C. for 1 hour and heat-treated. 10 of each sample
The coercive force and squareness ratio at 0 kHz and 500 kHz are B-
It was measured with an H loop analyzer. Table 1 shows the results. By using the apparatus of the present invention, a ribbon exhibiting excellent magnetic properties at high frequencies can be obtained.

[0027]

[Table 1]

Example 2 Casting was performed using an apparatus in which the position of the gas injection port was changed from the slit opening of the melt nozzle to 1.5 mm, 5 mm, 20 mm, 40 mm, and 50 mm. Other device structures and installation conditions are the same as those in the first embodiment. Using this apparatus, a ribbon having a contour thickness of about 11 μm was produced. Table 2 shows the contour plate thickness ta, the average plate thickness tb, the smoothness tb / ta, and the number n of pinholes per unit length. When the position from the melt nozzle was 1.5 mm, no ribbon could be obtained due to nozzle clogging during production.

[0029]

[Table 2]

Example 3 The width of the gas ejection port was set to 5 mm for a melt nozzle having a length of 5 mm.
, And casting was performed using a device having a gas ejection port whose length was changed to 3 mm (comparative example), 5 mm, and 30 mm (the present invention). Other structures and installation conditions of the apparatus are the same as those in the first embodiment. Using this apparatus, a ribbon having a contour thickness of about 11 μm was produced. Table 3 shows the contour plate thickness ta, the average plate thickness tb, the smoothness tb / ta, and the number n of pinholes per unit length. When the length of the gas outlet was 3 mm, it was not so effective in suppressing air pockets.

[0031]

[Table 3]

[0032]

By using the apparatus of the present invention, it is possible to easily manufacture an extremely thin ribbon having no holes and a smooth surface without using a pressure reducing mechanism or a gas heating apparatus. it can. Thus, at a practical level, the amorphous magnetic core can be used even at a higher frequency.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing the configuration of the apparatus of the present invention and the positional relationship between gas ejection ports.

FIG. 2 is a diagram showing an example of a shape of a gas ejection port.

FIG. 3 is a diagram showing a relationship between a length of a gas ejection port in a roll width direction and a length of a molten metal nozzle.

FIGS. 4A and 4B are diagrams showing a structural example for further enhancing the effect of the present invention.

[Explanation of symbols]

 1 Cooling Roll 2 Molten Nozzle 3 Gas Spout 4 Melt a Width of Slit of Melt Nozzle b Distance between Slit and Gas Spout c Distance between Roll and Gas Spout d Length of Molten Nozzle e Length of Gas Spout f Roll width θ Tilt of gas ejection axis

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-6-269907 (JP, A) JP-A-6-182503 (JP, A) JP-A-6-114508 (JP, A) JP-A-58-1983 90354 (JP, A) JP-A-6-292950 (JP, A) JP-A-4-356336 (JP, A) JP-A-62-1114747 (JP, A) JP-A-60-187452 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) B22D 11/06 360

Claims (1)

(57) [Claims] 1. A quenched metal ribbon manufacturing apparatus using a single cooling roll, comprising the following constituent parts. A crucible having a slit opening on the bottom surface for ejecting a molten alloy having a slit width of 0.2 to 0.4 mm. A He gas ejection port installed close to the upstream side of the opening; The position of the gas ejection port is 2 to 40 from the slit opening.
mm, 0.1 to 10 mm on the roll surface. The shape of the gas outlet is slit or porous, and has a length of 0.8 or more times the length 1 measured in the cooling roll width direction of the molten metal nozzle. A gas ejection port arranged so that the direction of gas ejection has an inclination of 10 to 90 degrees with respect to the tangent of the roll surface to which the molten metal contacts.