JP6593453B2 - Metal strip manufacturing apparatus and metal strip manufacturing method using the same - Google Patents

Description

  The present invention relates to a metal ribbon manufacturing apparatus and a metal ribbon manufacturing method using the same.

  It is known that various properties can be imparted to a metal material by a rapid solidification method. The rapid solidification method refers to a method of solidifying molten metal at a cooling rate of a certain level or higher. The rapid solidification method makes it possible, for example, to refine the crystal structure of the metal material, homogenize the solute distribution, expand the solid solution limit, and generate an amorphous layer (amorphous). Specifically, a strip casting method, a melt spinning method, an atomizing method, a melt spinning method, and the like are known as a method for producing a slab by a rapid solidification method.

  For example, International Publication No. 2012/090956 (Patent Document 1) describes the production of a Si alloy by an atomizing method. In addition, JP2013-161785A (Patent Document 2) describes the production of a Si alloy by a melt spinning method.

  In the rapid solidification method, the faster the molten metal is cooled, the finer the crystal grains. Among the rapid solidification methods, a manufacturing method having a particularly fast cooling rate is, for example, a melt spinning method. The melt spinning method is a method in which molten metal is jetted onto a roll that rotates at a high speed and rapidly cooled to produce a ribbon-like metal ribbon. In the melt spinning method, a small amount of molten metal is jetted and supplied onto a roll. Therefore, the cooling rate is fast.

  A metal ribbon containing fine crystal grains can be produced by the melt spinning method. However, the melt spinning method has a small amount of molten metal supplied onto the roll. Therefore, production capacity is limited, and mass production of metal ribbon is difficult.

  On the other hand, in the rapid solidification method, a method capable of mass production of a metal ribbon is, for example, a single roll strip casting method. The single roll strip casting method is a method in which molten metal is continuously supplied onto a rotating roll and rapidly cooled to produce a metal ribbon. A method for producing a slab using the strip casting method is described in, for example, Japanese Patent Application Laid-Open No. 2011-206835 (Patent Document 3) and Japanese Patent Application Laid-Open No. 2001-291514 (Patent Document 4).

  The manufacturing apparatus described in JP 2011-206835 A (Patent Document 3) is an aluminum clad plate manufacturing apparatus. The manufacturing apparatus includes a first roll having cooling ability and a first pool for storing the first molten metal. The first pool is surrounded by the surface of the first roll, the first front plate, the rear member, and both side members. The first front plate is positioned in front of the first roll in the rotation direction. The rear member is located rearward in the rotation direction of the first roll. The first front plate has a tip portion and is movably provided so that the distance between the tip portion and the surface of the first roll can be changed. The first roll rotates with the first metal layer while cooling the first molten metal in the first pool to form a semi-solid or solidified first metal layer on the surface of the first roll. The first front plate is urged so that the tip of the first front plate is always in surface contact with a semi-solid state surface of the first metal layer moving with the rotation of the first roll with a constant force. ing.

  The manufacturing method described in JP 2001-291514 A (Patent Document 4) is a manufacturing method of a negative electrode material for a non-aqueous electrolyte secondary battery. In this manufacturing method, an alloy raw material having a composition selected so that, when solidified, a Si phase and a phase of an intermetallic compound of Si and another metal element crystallize is melted, and then a strip casting method or centrifugal casting is performed. It is characterized by solidifying using a method to form a columnar crystal structure.

  In the strip casting method, the amount of molten metal supplied on the roll is larger than that in the melt spinning method. Therefore, mass production of metal ribbons is possible by the strip casting method. However, the strip casting method has a slower cooling rate of the molten metal than the melt spinning method. Therefore, the crystal grains are difficult to be miniaturized. Therefore, further refinement of crystal grains is required in the strip casting method.

International Publication No. 2012/0999056 JP 2013-161785 A JP2011-206835A JP 2001-291514 A

  In the manufacturing method disclosed in the above-mentioned patent document, there is a case where a metal ribbon containing fine crystal grains cannot be efficiently manufactured.

  An object of the present invention is to provide a metal ribbon production apparatus capable of efficiently producing a metal ribbon containing fine crystal grains.

  The manufacturing apparatus according to the present embodiment is a metal ribbon manufacturing apparatus using a single-roll strip casting method. The manufacturing apparatus includes a cooling roll, a tundish, and a molten metal remover. The cooling roll has an outer peripheral surface, and cools and solidifies the molten metal on the outer peripheral surface while rotating. The tundish can store the molten metal and supplies the molten metal onto the outer peripheral surface of the cooling roll. The molten metal remover is disposed downstream of the tundish in the rotation direction of the cooling roll with a gap between it and the outer peripheral surface of the cooling roll. The molten metal remover removes a portion of the molten metal corresponding to a thickness exceeding the width of the gap on the outer peripheral surface of the cooling roll. Thereby, the thickness of the molten metal on the outer peripheral surface of the cooling roll is regulated to the width of the gap between the outer peripheral surface of the cooling roll and the molten metal remover.

  The method for producing a metal ribbon according to this embodiment is a method for producing a metal ribbon by a single roll strip casting method using the above-described production apparatus. The manufacturing method includes a supplying process, a rapid cooling process, and a thickness adjusting process. In the supplying step, the molten metal in the tundish is supplied onto the outer peripheral surface of the cooling roll. In the rapid cooling step, the molten metal on the outer peripheral surface is rapidly cooled by a cooling roll to form a metal ribbon. In the thickness adjusting step, the molten metal remover removes a portion corresponding to the thickness exceeding the width of the above-described gap of the molten metal on the outer peripheral surface. Thereby, the thickness of the molten metal on the outer peripheral surface is regulated to the width of the gap between the outer peripheral surface of the cooling roll and the molten metal remover.

  If the apparatus for producing a metal ribbon according to the present embodiment is used, a metal ribbon containing fine crystal grains can be efficiently produced.

FIG. 1 is a cross-sectional view of a metal ribbon manufacturing apparatus according to the present embodiment. FIG. 2 is an enlarged cross-sectional view of the vicinity of the tip of the molten metal remover of the manufacturing apparatus. FIG. 3 is a view showing the mounting angle of the molten metal remover. FIG. 4 is a cross-sectional view of a manufacturing apparatus according to another embodiment, which is different from FIGS. 1 to 3. FIG. 5 is a cross-sectional view of a manufacturing apparatus according to another embodiment, which is different from FIGS. FIG. 6 is a view showing a cross-sectional shape of a molten metal remover. FIG. 7 is a diagram showing a cross-sectional shape of another molten metal remover different from FIG. FIG. 8 is a diagram showing a cross-sectional shape of another molten metal remover different from those in FIGS. 6 and 7. FIG. 9 is an electron microscope (SEM) photograph of a cross section of a metal ribbon manufactured by the manufacturing method according to the present embodiment. FIG. 10 is an electron microscope (SEM) photograph of a cross section of a metal ribbon produced without using a molten metal remover.

  The manufacturing apparatus according to the present embodiment is a metal ribbon manufacturing apparatus using a single-roll strip casting method. The manufacturing apparatus includes a cooling roll, a tundish, and a molten metal remover. The cooling roll has an outer peripheral surface, and cools and solidifies the molten metal on the outer peripheral surface while rotating. The tundish can store the molten metal and supplies the molten metal onto the outer peripheral surface of the cooling roll. The molten metal remover is disposed downstream of the tundish in the rotation direction of the cooling roll with a gap between it and the outer peripheral surface of the cooling roll. The molten metal remover removes a portion (hereinafter also referred to as a surface portion) corresponding to a thickness exceeding the width of the above-mentioned gap of the molten metal. Thereby, the thickness of the molten metal on the outer peripheral surface of the cooling roll is regulated to the width of the gap between the outer peripheral surface of the cooling roll and the molten metal remover.

  The manufacturing apparatus according to this embodiment includes a molten metal remover. The molten metal remover contacts the molten metal when the free surface of the molten metal (the surface on the side where the molten metal is not in contact with the cooling roll) is in a liquid or semi-solid state. The molten metal remover removes the surface portion of the molten metal on the outer peripheral surface. Thereby, the thickness of the molten metal on the outer peripheral surface of the cooling roll is regulated to the width of the gap between the outer peripheral surface of the cooling roll and the molten metal remover. Therefore, the molten metal on the outer peripheral surface of the cooling roll becomes thin. When the molten metal becomes thinner, the cooling rate of the molten metal increases. As a result, the metal ribbon crystal grains are reduced. That is, a metal ribbon containing fine crystal grains can be efficiently produced using strip casting.

  Preferably, the width of the gap between the outer peripheral surface of the cooling roll and the molten metal remover is narrower than the thickness of the molten metal on the outer peripheral surface of the cooling roll upstream of the molten metal remover in the rotation direction of the cooling roll.

  In this case, the molten metal on the outer peripheral surface of the cooling roll becomes thinner. Therefore, the cooling rate of the molten metal is further increased. As a result, the crystal grains of the metal ribbon are further refined.

  Preferably, the tundish includes a supply end that is disposed in the vicinity of the outer peripheral surface of the cooling roll and guides the molten metal onto the outer peripheral surface of the cooling roll. The molten metal remover is further disposed above the supply end of the tundish.

  In this case, the molten metal is cooled while being wound on the cooling roll. Therefore, the time for which the molten metal is in contact with the outer peripheral surface of the cooling roll is long, and the cooling time for the molten metal is long. As a result, the crystal grains of the metal ribbon are further refined.

  Preferably, the molten metal remover is disposed to face the outer peripheral surface of the cooling roll, and has a heat removal surface that comes into contact with the molten metal passing through the gap between the outer peripheral surface of the cooling roll and the molten metal remover.

  In this case, the molten metal is extracted from not only the surface in contact with the cooling roll (hereinafter also referred to as the solidified portion) but also the surface in contact with the molten metal remover. Therefore, the cooling rate of molten metal increases. As a result, the crystal grains of the metal ribbon are further refined.

  The method for producing a metal ribbon according to this embodiment is a method for producing a metal ribbon by a single roll strip casting method using the above-described production apparatus. The manufacturing method includes a supplying process, a rapid cooling process, and a thickness adjusting process. In the supplying step, the molten metal in the tundish is supplied onto the outer peripheral surface of the cooling roll. In the rapid cooling step, the molten metal on the outer peripheral surface is rapidly cooled by a cooling roll to form a metal ribbon. In the thickness adjusting step, the molten metal remover removes the surface portion of the molten metal on the outer peripheral surface. Thereby, the thickness of the molten metal on the outer peripheral surface is regulated to the width of the gap between the outer peripheral surface of the cooling roll and the molten metal remover.

  The manufacturing method according to the present embodiment includes a thickness adjusting step. Thereby, the molten metal on the outer peripheral surface of the cooling roll becomes thin. Therefore, the cooling rate of molten metal increases. As a result, the crystal grains of the metal ribbon are refined. That is, it is possible to efficiently manufacture a metal ribbon containing fine crystal grains by using a strip casting method.

  Hereinafter, this embodiment will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

[Manufacturing equipment]
FIG. 1 is a cross-sectional view of an example of a metal ribbon manufacturing apparatus according to the present embodiment. The manufacturing apparatus 1 includes a cooling roll 2, a tundish 4, and a molten metal remover 5.

[Cooling roll]
The cooling roll 2 has an outer peripheral surface, and cools and solidifies the molten metal 3 on the outer peripheral surface while rotating. The cooling roll 2 includes a cylindrical body portion and a shaft portion (not shown). A trunk | drum has the said outer peripheral surface. The shaft portion is disposed at the central axis position of the body portion and is attached to a drive source (not shown). The cooling roll 2 rotates around the central axis 9 of the cooling roll 2 by a driving source.

  The material of the cooling roll 2 is preferably a material having high hardness and high thermal conductivity. The material of the cooling roll 2 is, for example, one type selected from the group consisting of copper and copper alloys. Preferably, the material of the cooling roll 2 is copper. The cooling roll 2 may further have a coating on the surface. Thereby, the hardness of the cooling roll 2 increases. The coating is, for example, one or two selected from the group consisting of a plating coating and a cermet coating. The plating film is, for example, one or two selected from the group consisting of chromium plating and nickel plating. Cermet coatings include, for example, tungsten (W), cobalt (Co), titanium (Ti), chromium (Cr), nickel (Ni), silicon (Si), aluminum (Al), boron (B), and these elements 1 type (s) or 2 or more types selected from the group consisting of carbides, nitrides and carbonitrides. Preferably, the surface layer of the cooling roll 2 is copper, and the cooling roll 2 further has a chromium plating film on the surface.

  X shown in FIG. 1 is the rotation direction of the cooling roll 2. When the metal ribbon 6 is manufactured, the cooling roll 2 rotates in a certain direction X. Thereby, in FIG. 1, the molten metal 3 in contact with the cooling roll 2 partially solidifies on the outer peripheral surface of the cooling roll 2, and moves with the rotation of the cooling roll 2.

  The cooling roll 2 has a cooling zone downstream of the tundish 4 described later in the rotation direction of the cooling roll 2 and before reaching the molten metal remover 5 described later. In the cooling zone, the molten metal 3 supplied on the outer peripheral surface of the cooling roll 2 has a free surface. Therefore, rapid cooling is possible. When the molten metal 3 does not have a free surface, that is, when the molten metal 3 is further present on the solidified portion of the molten metal 3, the solidified portion cannot be sufficiently removed. This is because heat is continuously applied to the solidified portion from the molten metal 3 existing on the solidified portion. In the cooling zone, the molten metal 3 has a free surface by being supplied onto the outer peripheral surface of the cooling roll 2. Therefore, the solidified part can be sufficiently removed and rapid cooling becomes possible. As a result, the metal ribbon 6 having finer crystal grains can be obtained.

  The roll peripheral speed of the cooling roll 2 is appropriately set in consideration of the cooling speed and manufacturing efficiency of the molten metal 3. If the roll peripheral speed is fast, the metal ribbon 6 is easily peeled from the outer peripheral surface of the cooling roll 2. Therefore, the lower limit of the roll peripheral speed is preferably 50 m / min, more preferably 80 m / min, and still more preferably 120 m / min. The upper limit of the roll peripheral speed is not particularly limited, but is, for example, 500 m / min in consideration of the facility capacity. The roll peripheral speed can be obtained from the roll diameter and the rotation speed.

  The cooling roll 2 may be filled with a heat removal solvent. Thereby, the molten metal 3 can be efficiently removed. A solvent is 1 type, or 2 or more types selected from the group which consists of water, an organic solvent, and oil, for example. The solvent may stay inside the cooling roll 2 or may be circulated to the outside.

[Tundish]
The tundish 4 can store the molten metal 3 and supplies the molten metal 3 on the outer peripheral surface of the cooling roll 2.

  In the present embodiment, the tundish 4 may be always heated. In this case, the molten state of the high melting point molten metal 3 can be maintained. Therefore, the molten metal 3 can be removed using the molten metal remover 5 described later in the molten state. The heating temperature is not particularly limited as long as it is equal to or higher than the liquidus temperature of the raw material. When manufacturing a Si alloy, heating temperature is 1200 degreeC or more, for example, and a more preferable heating temperature is 1500 degreeC or more. When manufacturing the alloy material for magnets, heating temperature is 1000 degreeC or more, for example.

[Molten metal remover]
The molten metal remover 5 is a member that extends along the axial direction of the cooling roll 2. An example of the molten metal remover 5 is a plate-like member arranged in parallel with the axial direction of the cooling roll 2 as shown in FIG. The molten metal remover 5 is disposed downstream of the tundish 4 in the rotation direction of the cooling roll 2 with a gap between the outer periphery of the cooling roll 2. The molten metal remover 5 includes a main body portion 51 and a tip portion 50 disposed to face the outer peripheral surface of the cooling roll 2. The shape of the tip 50 is not particularly limited.

  FIG. 2 is an enlarged cross-sectional view of the vicinity of the tip 50 of the molten metal remover 5 of the manufacturing apparatus 1 (the range surrounded by the broken line in FIG. 1). Referring to FIG. 2, molten metal remover 5 is arranged with a gap A between the outer peripheral surface of cooling roll 2. The molten metal remover 5 regulates the thickness of the molten metal 3 on the outer peripheral surface of the cooling roll 2 to the width of the gap A between the outer peripheral surface of the cooling roll 2 and the molten metal remover 5. Specifically, the molten metal 3 upstream of the molten metal remover 5 in the rotation direction of the cooling roll 2 may be thicker than the width of the gap A. In this case, the molten metal 3 corresponding to the thickness exceeding the width of the gap A is removed by the molten metal remover 5. Thereby, the thickness of the molten metal 3 is reduced to the width of the gap A. By reducing the thickness of the molten metal 3, the cooling rate of the molten metal 3 is increased. For this reason, the crystal grains of the metal ribbon 6 are refined.

  The width of the gap A is preferably narrower than the thickness B of the molten metal 3 on the outer peripheral surface on the upstream side in the rotation direction of the cooling roll 2 relative to the molten metal remover 5. In this case, the molten metal 3 on the outer peripheral surface of the cooling roll 2 becomes thinner. Therefore, the cooling rate of the molten metal 3 is further increased. As a result, the crystal grains of the metal ribbon 6 are further refined.

  The width of the gap A between the outer peripheral surface of the cooling roll 2 and the molten metal remover 5 is the shortest distance between the molten metal remover 5 and the outer peripheral surface of the cooling roll 2. The width of the gap A is appropriately set according to the intended cooling rate and production efficiency. The narrower the gap A, the thinner the molten metal 3 after thickness adjustment. For this reason, the cooling rate of the molten metal 3 is further increased. As a result, the crystal grains of the metal ribbon 6 can be easily refined. Therefore, the upper limit of the gap A is preferably 400 μm, more preferably 250 μm, still more preferably 100 μm, still more preferably 50 μm, and further preferably 30 μm. When the cooling roll 2 has chromium plating and nickel plating on the surface, the cooling rate is slower than when the surface of the cooling roll 2 is copper. Therefore, in this case, it is preferable to narrow the gap A. Although the minimum of the clearance gap A is not specifically limited, For example, it is 10 micrometers.

  Of the outer peripheral surface of the cooling roll 2, the distance between the point where the molten metal 3 is supplied from the tundish 4 and the point where the molten metal remover 5 is disposed is appropriately set. If the molten metal remover 5 is disposed within a range where the free surface of the molten metal 3 (the surface on the side where the molten metal 3 is not in contact with the cooling roll 2) is in contact with the molten metal remover 5 in a liquid or semi-solid state. Good.

  FIG. 3 is a view showing the mounting angle of the molten metal remover 5. Referring to FIG. 3, for example, molten metal remover 5 includes surface PL <b> 1 including central axis 9 and supply end 7 of cooling roll 2, central axis 9 of cooling roll 2 and tip 50 of molten metal remover 5. Is arranged such that the angle θ formed by the surface PL2 including the surface is constant. (Hereinafter, this angle θ is referred to as an attachment angle θ.) The attachment angle θ can be set as appropriate. The upper limit of the mounting angle θ is 45 °, for example. The upper limit of the mounting angle θ is preferably 30 °. The lower limit of the attachment angle θ is not particularly limited, but is preferably in a range where the molten metal remover 5 is not in direct contact with the molten metal 3 on the tundish 4.

  1 to 3, the molten metal remover 5 preferably has a heat removal surface 8. The heat removal surface 8 is disposed to face the outer peripheral surface of the cooling roll 2. The heat removal surface 8 is in contact with the molten metal 3 that passes through the gap between the outer peripheral surface of the cooling roll 2 and the molten metal remover 5.

The material of the molten metal remover 5 is preferably a refractory material. The molten metal remover 5 is, for example, aluminum oxide (Al ₂ O ₃ ), silicon monoxide (SiO), silicon dioxide (SiO ₂ ), chromium oxide (Cr ₂ O ₃ ), magnesium oxide (MgO), titanium oxide (TiO ₂ ). ), Aluminum titanate (Al ₂ TiO ₅ ), and zirconium oxide (ZrO ₂ ). Preferably, the molten metal remover 5 is one selected from the group consisting of aluminum oxide (Al ₂ O ₃ ), silicon dioxide (SiO ₂ ), aluminum titanate (Al ₂ TiO ₅ ), and magnesium oxide (MgO). Contains 2 or more.

  The manufacturing apparatus 1 described above removes the surface portion of the molten metal 3 on the outer peripheral surface of the cooling roll 2 by the molten metal remover 5. The surface portion of the molten metal 3 is a portion corresponding to a thickness exceeding the width of the gap A between the outer peripheral surface of the cooling roll 2 and the molten metal remover 5 in the molten metal 3 on the outer peripheral surface of the cooling roll 2. means. Thereby, the thickness of the molten metal 3 on the outer peripheral surface of the cooling roll 2 is regulated. Therefore, the molten metal 3 on the outer peripheral surface of the cooling roll 2 becomes thin. As the molten metal 3 becomes thinner, the cooling rate of the molten metal 3 increases. Therefore, if a metal ribbon is manufactured using the manufacturing apparatus 1, the metal ribbon 6 having finer crystal grains can be obtained.

  The apparatus for manufacturing a metal ribbon according to this embodiment is not limited to the above-described manufacturing apparatus 1.

  In the manufacturing apparatus 1 shown in FIG. 1, the molten metal 3 is supplied from the side of the cooling roll 2. On the other hand, the molten metal 3 can also be supplied from above the cooling roll 2.

  FIG. 4 is a cross-sectional view of the manufacturing apparatus 10 according to another embodiment, which is different from FIGS. 1 to 3. With reference to FIG. 4, the tundish 4 and the supply end 7 are disposed above the cooling roll 2. The molten metal remover 5 is disposed below the supply end 7. Other configurations of the manufacturing apparatus 10 are the same as those of the manufacturing apparatus 1. In the manufacturing apparatus 10, the molten metal 3 is supplied from above the cooling roll 2 onto the outer peripheral surface of the cooling roll 2. The molten metal 3 supplied onto the outer peripheral surface of the cooling roll 2 is regulated by the molten metal remover 5 in the same manner as the manufacturing apparatus 1. As a result, the thickness of the molten metal 3 on the outer peripheral surface of the cooling roll 2 is reduced to the width of the gap A between the outer peripheral surface of the cooling roll 2 and the molten metal remover 5.

  In the manufacturing apparatus 10, the molten metal 3 is cooled from the top of the cooling roll 2 down on the outer peripheral surface of the cooling roll 2. On the other hand, in the manufacturing apparatus 1 shown in FIG. 1, the molten metal 3 is supplied from the side of the cooling roll 2 in the same direction as the rotation direction of the cooling roll 2. Further, the molten metal 3 reaches the apex of the cooling roll 2 while being wound up by the cooling roll 2, and is then cooled down on the outer peripheral surface of the cooling roll 2. Therefore, compared with the manufacturing apparatus 10, when the manufacturing apparatus 1 is used, the time during which the molten metal 3 is in contact with the outer peripheral surface of the cooling roll 2 is long. Therefore, the cooling time of the molten metal 3 is long. In this case, the crystal grains of the metal ribbon 6 are further refined. Therefore, it is preferable that the manufacturing apparatus 1 shown in FIG. 1, that is, the molten metal remover 5 is disposed above the supply end 7 of the tundish 4.

  As shown in FIGS. 1 to 4, one molten metal remover 5 may be arranged, or a plurality of molten metal removers 5 may be arranged continuously with respect to the rotation direction of the cooling roll 2. When a plurality of molten metal removers 5 are arranged, the molten metal remover 5 arranged on the downstream side in the rotation direction of the cooling roll 2 is connected to the cooling roll 2 rather than the molten metal remover 5 arranged on the upstream side in the rotation direction of the cooling roll 2. Place them close together. And it arrange | positions so that the clearance gap A between the molten metal remover 5 located most downstream in the rotation direction of the cooling roll 2 and the outer peripheral surface of the cooling roll 2 may become the smallest. By arranging a plurality of the molten metal removers 5, the molten metal 3 can be removed stepwise. In this case, the burden on one molten metal remover 5 is reduced. In this case, precise control of the thickness of the molten metal 3 is further facilitated.

  The molten metal remover 5 may be arranged in an orientation along the normal line of the cooling roll 2 as shown in FIGS. 1 to 4, or different from the normal line of the cooling roll 2 as shown in FIG. 5. You may arrange | position in direction. In FIG. 5, the molten metal remover 5 is disposed so as to be inclined toward the rotation direction of the cooling roll 2 rather than the normal direction of the cooling roll 2. In this case, it is easy to remove a portion above the width of the gap A from the molten metal 3 on the outer peripheral surface of the cooling roll 2. That is, it is easy to regulate the thickness of the molten metal 3 on the outer peripheral surface of the cooling roll 2. Further, in FIG. 5, the cross-sectional shape of the molten metal remover 5 is made different from that shown in FIGS. In this case, the molten metal 3 can be removed more efficiently. The direction of the molten metal remover 5 is appropriately set so that the thickness of the molten metal 3 can be easily regulated.

  The cross-sectional shape of the cross section perpendicular to the roll axis of the tip 50 (the end in contact with the molten metal 3) of the molten metal remover 5 may be a rectangle as shown in FIGS. But you can. The other shape may be, for example, a triangle as shown in FIG. Alternatively, as shown in FIGS. 5 and 7, the width of the gap between the tip 50 on the inlet side of the molten metal 3 of the molten metal remover 5 and the outer peripheral surface of the cooling roll 2, and the molten metal of the molten metal remover 5. 3 may have a shape in which the width of the gap between the distal end portion 50 on the outlet side 3 and the outer peripheral surface of the cooling roll 2 is different. The cross-sectional shape of the distal end portion 50 of the molten metal remover 5 is appropriately set so that the thickness of the molten metal 3 can be easily regulated.

[Production method]
The manufacturing method of the metal ribbon 6 according to this embodiment is a manufacturing method using the manufacturing apparatus 1 or 10 described above. The manufacturing method includes a supplying process, a rapid cooling process, and a thickness adjusting process.

  First, the molten metal 3 is prepared. The composition of the molten metal 3 is appropriately set according to the composition of the target metal ribbon 6. For example, when manufacturing a Si alloy, the molten metal 3 is, for example, silicon (Si), titanium (Ti), chromium (Cr), vanadium (V), manganese (Mn), iron (Fe), cobalt (Co). In addition, one or more selected from the group consisting of nickel (Ni), zinc (Zn), aluminum (Al), copper (Cu), and tin (Sn) are contained, and the balance consists of impurities. Or when manufacturing the alloy material for neodymium magnets, the molten metal 3 contains neodymium (Nd), boron (B), and iron (Fe), for example, and the remainder consists of impurities. The molten metal 3 is manufactured by heating the raw material which has the above-mentioned chemical composition more than melting | fusing point.

  The molten metal 3 is manufactured by putting the raw material which has the above-mentioned chemical composition in a crucible, and heating. Examples of the heating method include high frequency induction heating, arc heating, plasma arc heating, resistance heating, and electron beam impact heating. The heating temperature is not particularly limited as long as it is equal to or higher than the liquidus temperature of the raw material. When the Si alloy is manufactured, the heating temperature is, for example, 1200 ° C. or higher, and more preferably 1500 ° C. or higher. When manufacturing the alloy material for magnets, heating temperature is 1000 degreeC or more, for example.

[Supply process]
In the supplying step, the molten metal 3 in the tundish 4 is supplied onto the outer peripheral surface of the cooling roll 2. First, the molten metal 3 is supplied from the crucible to the tundish 4. The molten metal 3 may be supplied from the crucible to the tundish 4 by pouring the molten metal 3 directly by tilting the crucible. Alternatively, the molten metal 3 may be supplied from the crucible to the tundish 4 using a nozzle or the like. Subsequently, the molten metal 3 is supplied onto the outer peripheral surface of the cooling roll 2 from the supply end 7 of the tundish 4. The cooling roll 2 rotates around the central axis 9 of the cooling roll 2 at a constant speed as described above. When the molten metal 3 supplied from the tundish 4 comes into contact with the outer peripheral surface of the cooling roll 2, the molten metal 3 partially solidifies and is transferred to the cooling roll 2. The molten metal 3 moves with the rotation of the cooling roll 2. At this time, the surface (free surface) of the molten metal 3 that is not in contact with the outer peripheral surface of the cooling roll 2 is in a liquid or semi-solid state.

  In the supplying step, the tundish 4 may be always heated. In this case, the molten state of the high melting point molten metal 3 can be maintained. Therefore, the molten metal 3 can be removed using the molten metal remover 5 in the molten state. The heating temperature is not particularly limited as long as it is equal to or higher than the liquidus temperature of the raw material. When manufacturing a Si alloy, heating temperature is 1200 degreeC or more, for example, and a more preferable heating temperature is 1500 degreeC or more. When manufacturing the alloy material for magnets, heating temperature is 1000 degreeC or more, for example.

[Rapid cooling process]
In the rapid cooling step, the molten metal 3 on the outer peripheral surface is rapidly cooled by the cooling roll 2 to form the metal ribbon 6. The rapid cooling process starts when the molten metal 3 is supplied onto the outer peripheral surface of the cooling roll 2 in the supply process described above. In the rapid cooling step, the molten metal 3 is cooled from the solidified portion.

  In the rapid cooling step, the cooling roll 2 has a cooling zone downstream of the tundish 4 in the rotation direction of the cooling roll 2 and before reaching the molten metal remover 5. In the cooling zone, the molten metal 3 supplied on the outer peripheral surface of the cooling roll 2 has a free surface. Therefore, rapid cooling is possible. When the molten metal 3 does not have a free surface, that is, when the molten metal 3 is further present on the solidified part, the solidified part cannot be sufficiently removed. This is because heat is continuously applied to the solidified portion from the molten metal 3 existing on the solidified portion. In the cooling zone, the molten metal 3 has a free surface by being supplied onto the outer peripheral surface of the cooling roll 2. Therefore, the solidified part can be sufficiently removed and rapid cooling becomes possible. As a result, it is possible to manufacture the metal ribbon 6 having finer crystal grains.

[Thickness adjustment process]
In the thickness adjusting step, the thickness of the molten metal 3 on the outer peripheral surface of the cooling roll 2 is changed between the outer peripheral surface of the cooling roll 2 and the molten metal remover 5 by the molten metal remover 5 during the rapid cooling step. Restrict to A width. As soon as the molten metal 3 is supplied onto the outer peripheral surface of the cooling roll 2, the whole does not solidify, but gradually solidifies from the solidified portion. The free surface of the molten metal 3 contacts the molten metal remover 5 in a liquid or semi-solid state. The hardness of the liquid or semi-solid molten metal 3 is low. Therefore, if the thickness of the molten metal 3 is greater than the width of the gap A, the free surface of the molten metal 3 in a liquid or semi-solid state is blocked or removed. Thereby, the molten metal 3 becomes thin. If the molten metal 3 is thin, the cooling rate of the molten metal 3 is increased. As a result, it is possible to manufacture the metal ribbon 6 having finer crystal grains.

  By arranging the heat removal surface 8, the molten metal 3 is also removed from the heat removal surface 8 in addition to the solidified portion. In this case, the cooling rate of the molten metal 3 is increased. The area and shape of the heat removal surface 8 are appropriately set. For example, as shown in FIG. 8, the area of the heat removal surface 8 can be increased by making the tip 50 of the molten metal remover 5 L-shaped. In this case, the cooling rate of the molten metal 3 can be further increased.

  The molten metal 3 thinned in the thickness adjusting step is subsequently cooled on the cooling roll 2. The molten metal 3 at this time is thin. Therefore, the cooling rate is remarkably fast. As a result, the crystal grains of the metal ribbon 6 become fine. When the entire molten metal 3 is solidified, it becomes a metal ribbon 6. The metal ribbon 6 is collected away from the outer peripheral surface of the cooling roll 2. Through the above process, the metal ribbon 6 of the present embodiment can be manufactured.

  Using the manufacturing apparatus described in Examples 1 to 3 below, a metal ribbon of Si alloy was manufactured. The raw material contained nickel (Ni), titanium (Ti) and silicon (Si). The composition of the raw material was Ni: Ti: Si = 25: 17: 58 by mass ratio. 1 kg of the mixed raw material was heated to 1450 ° C. to produce molten metal. Molten metal was fed from the tundish onto a chill roll. The cooling roll was a cooling roll in which the outer peripheral surface was coated with copper and the inside was cooled with water. The diameter of the cooling roll was 20 cm and the width was 18 cm. The peripheral speed of the roll was 120 m / min. The metal ribbon of the Si alloy obtained in Examples 1 to 3 was cut, and the cross section was observed using a scanning electron microscope (SEM).

[Example 1]
In Example 1, an Si alloy metal ribbon was manufactured using the manufacturing apparatus of the present embodiment. That is, a metal ribbon of Si alloy was manufactured using a molten metal remover. The molten metal remover was a flat alumina plate having a thickness of 3 mm. The width of the gap between the molten metal remover and the outer peripheral surface of the cooling roll was 80 μm.

[Example 2]
In Example 2, the molten metal remover was removed from the production apparatus of the present embodiment to produce a Si alloy metal ribbon. That is, a Si alloy metal ribbon was manufactured without using a molten metal remover.

[Example 3]
In Example 3, a metal ribbon of Si alloy is manufactured on the cooling roll using a manufacturing apparatus that does not have a cooling zone between the tundish and the molten metal remover under the same conditions as in Example 1. did. That is, the molten metal was supplied to the molten metal remover without having a free surface.

[Evaluation results]
[Example 1]
FIG. 9 is an electron microscope (SEM) photograph of a cross section of a metal ribbon manufactured by the manufacturing method according to the present embodiment (with a molten metal remover). The average thickness of the metal ribbon manufactured by the method according to the present embodiment was 80 μm. Furthermore, the size of the Si phase crystal grains of the metal ribbon produced by the method according to the present embodiment (corresponding to the width of the gray portion in FIG. 9) was 2 μm or less.

[Example 2]
FIG. 10 is an electron microscope (SEM) photograph of a cross section of a metal ribbon manufactured by a conventional method (without a molten metal remover). The average film thickness of the metal ribbon manufactured by the conventional method was 440 μm. Furthermore, the size of the Si phase crystal grains of the metal ribbon produced by the conventional method (corresponding to the width of the gray portion in FIG. 10) was 20 to 30 μm.

[Example 3]
In Example 3 produced by removing the molten metal having no free surface with a molten metal remover, the size of the Si phase crystal grains of the metal ribbon was 10 to 15 μm.

  The embodiment of the present invention has been described above. However, the above-described embodiment is merely an example for carrying out the present invention. Therefore, the present invention is not limited to the above-described embodiment, and can be implemented by appropriately changing the above-described embodiment without departing from the spirit thereof.

DESCRIPTION OF SYMBOLS 1,10 Manufacturing apparatus 2 Cooling roll 3 Molten metal 4 Tundish 5 Molten metal remover 6 Metal ribbon 7 Supply end 8 Heat removal surface

Claims (4)

An apparatus for producing a metal ribbon by a single roll strip casting method,
A cooling roll having an outer peripheral surface and cooling and solidifying the molten metal on the outer peripheral surface while rotating;
A tundish capable of storing the molten metal and supplying the molten metal on the outer peripheral surface;
A surface corresponding to a thickness of the molten metal on the outer peripheral surface that exceeds the width of the gap, and is disposed downstream of the tundish in the rotation direction of the cooling roll with the outer peripheral surface. A molten metal remover that removes a portion and regulates the thickness of the molten metal to the width of the gap ;
The molten metal remover is disposed in a range where the surface of the molten metal that is not in contact with the cooling roll is in contact with the molten metal remover in a liquid or semi-solid state,
The molten metal remover is disposed opposite to the outer peripheral surface and has a heat removal surface that comes into contact with the molten metal passing through the gap, and the heat removal surface cools the molten metal . Manufacturing equipment. The metal ribbon manufacturing apparatus according to claim 1,
The width of the said clearance gap is a manufacturing apparatus of a metal strip which is narrower than the thickness of the said molten metal on the said outer peripheral surface in the said rotation direction upstream rather than the said molten metal remover. A metal ribbon manufacturing apparatus according to claim 1 or 2,
The tundish is disposed near the outer peripheral surface, and includes a supply end that guides the molten metal onto the outer peripheral surface,
The molten metal remover is an apparatus for producing a metal ribbon, which is disposed above the supply end. A method for producing a metal ribbon by a single roll strip casting method using the apparatus for producing a metal ribbon according to any one of claims 1 to 3 ,
Supplying the molten metal in the tundish onto the outer peripheral surface of the cooling roll;
A step of rapidly cooling the molten metal on the outer peripheral surface by the cooling roll to form a metal ribbon;
The molten metal remover removes a portion corresponding to the thickness of the molten metal on the outer peripheral surface that exceeds the width of the gap, and regulates the thickness of the molten metal on the outer peripheral surface to the width of the gap. A method for producing a metal ribbon.

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