JP2006175508A - Method for molding amorphous alloy and device therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily produce amorphous molded parts with various deformed shapes including a one-face-opened or through type hollow shape free from cavities and having an extremely high solid degree. <P>SOLUTION: A method for molding amorphous alloy comprises: a melting step where an amorphous alloy (1) is subjected to levitation melting; a tapping step where the molten metal (1b) of the amorphous alloy (1) is tapped to a lower casting mold located below the molten metal (1b); and a pressure rapid cooling step where an upper casting mold (1b) is pressed against the lower casting mold (2), and the molten metal (1b) in the lower casting mold (2) is pressed. In this way, the exhaust of gas occluded in the molten metal is performed by the rapid cooling and pressurizing of the molten metal, thus a sound amorphous metallic member free from cavities and having a free shape can be molded. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method and apparatus for forming an amorphous alloy that is excellent in quality and that can be freely shaped.

  Conventionally, amorphous alloys have only been able to produce thin ribbons and thin wires because they require ultra-rapid cooling, but due to recent research results, for example, thick plate-like ones such as the face part of golf club heads or Various amorphous alloys (amorphous alloys) such as those in bulk (bulk) have been gradually put into practical use.

  In general, amorphous alloys have a low Young's modulus (easy to bend) while maintaining mechanical strength such as high strength and high hardness. For example, it is going to be applied to a club face portion that requires high resilience characteristics for increasing the flight distance of a ball, a medical guide wire that requires flexibility as a wire rod, and the like.

  However, in the case of a plate material or bulk material, the method of forming the amorphous alloy (50) was produced by casting the molten metal in a water-cooled mold, so that (a) a fine nest (51) was generated in the molding material. There are problems such as damage due to impact or repeated bending, and (b) that only simple shapes such as solid blocks or plates can be molded.

  One of the molding methods is an airborne dissolution method (Japanese Patent Laid-Open No. 2002-224249), which will be briefly described below. The method described in JP-A-2002-224249 is “a melting step of melting an alloy material of an amorphous alloy member by a floating melting method using a high-frequency induction heating coil to obtain the molten metal, and a water-cooled casting mold positioned below the molten metal And a casting process for casting the molten metal and a quenching process for quenching the molten metal with a water-cooled casting mold by this casting.

  Since casting into the casting mold is merely a flow of molten metal, it is easy to entrain the ambient atmosphere gas and solidifies before releasing the entrained gas and the occluded gas that occludes the ambient atmosphere gas during melting for rapid cooling. As a result, there is a problem that these are confined in the amorphous alloy and various nests (51) are generated from a fine nest to a large nest. This nest (51) naturally acts as a defect in the amorphous alloy (50), and greatly reduces the mechanical strength of the molded product of the amorphous alloy (50).

In the case of casting as described above, naturally, the shape of the mold is limited, and it has been difficult to mold a complicated shape such as a hollow molded product. In addition, in the case of a thick plate, the cooling rate was insufficient, and only a thin plate could be made amorphous.
JP 2002-224249 A

  SUMMARY OF THE INVENTION An object of the present invention is to make it easy to manufacture amorphous products having various shapes such as a hollow shape having a single-sided opening or a penetrating shape, without generating a nest and having a very high solidity. .

  “Claim 1” relates to a method for forming an amorphous alloy according to the present invention, wherein “a melting step for floatingly melting an amorphous alloy (1) and a molten metal (1b) of the amorphous alloy (1)” A pouring step of pouring the molten metal (1b) into the lower casting mold (2), and the molten metal (1b) in the lower casting mold (2) by pressing the upper casting mold (3) against the lower casting mold (2) And pressurizing and quenching step of pressing.

  “Claim 2” relates to a molding apparatus (A) for an amorphous alloy (1) to which the above method is applied, “a high-frequency induction heating coil (4) for floatingly dissolving the amorphous alloy (1) and a high-frequency induction heating”. The lower casting mold (2), which is disposed below the coil (4) and receives the amorphous alloy molten metal (1b) melted by the high frequency induction heating coil (4), is pressed against the lower casting mold (2). And the upper casting mold (3) that pressurizes and quenches the molten metal (1b) in the lower casting mold (2) with a press ”.

  “Claim 3” relates to the high-frequency induction heating coil (4) used in the apparatus (A). “The high-frequency induction heating coil (4) includes a plurality of turns and an upper stabilization coil (4b) composed of a plurality of turns. It is composed of the lower levitation heating coil (4a) constructed, and the coil diameters (R1) (R2) ... are gradually becoming smaller as they go to the casting mold (2) (3) side, respectively. '' It is characterized by.

  In the method of the present invention, the upper casting mold (3) is pressed against the lower casting mold (2) and the molten metal (1b) in the lower casting mold (2) is pressed and rapidly cooled by pressure. As a result, the gas in the molten metal (1) was forcibly pushed out, and it became possible to form a sound molded product (1c) having no nest (51) inside. Further, since pressing and rapid cooling are performed, the cooling rate is accelerated as compared with the conventional method, and a thicker member can be formed. In addition, because it is press-molded, the shape of the upper and lower casting molds (2) and (3) can be formed appropriately, so that gears, single-sided or through-hole shaped hollow members, test pieces, and other irregularly shaped members can be easily formed. It became possible to mold.

  The present invention will be described below with reference to the illustrated embodiments. The basic structure of the apparatus (A) is a high-frequency induction heating coil (4) for floating and melting the amorphous alloy (1), and the high-frequency induction heating coil (4) disposed below the high-frequency induction heating coil (4). The lower casting mold (2) that accepts the molten amorphous alloy (1b) melted by) and the lower casting mold (2) by pressing the molten metal (1b) in the lower casting mold (2) The upper casting mold (3) for pressure and rapid cooling and the raw material supply arm (5) for supplying the amorphous alloy material (1a) to the center of the high frequency induction heating coil (4) are configured.

  As the high-frequency induction heating coil (4), a metal pipe (generally a copper pipe is used) is spirally wound for water cooling. Figure 1 shows the upper stabilizing coil (4b) doubled and the lower levitation heating coil (4a) doubled in the opposite direction. Not. In FIG. 2 and subsequent figures, a single-upper one is shown for convenience. The wound high-frequency induction heating coil (4) is turned upside down, and the lower coil is a levitation heating coil (4a) and the upper coil is a stabilization coil (4b). When the levitation heating coil (4a) and the stabilization coil (4b) each have a plurality of turns, as shown in FIG. 1, in the case of this embodiment, the coil diameters (R1), (R2). ) It gets smaller gradually as you go to the side.

  The lower casting mold (2) is disposed below and coincides with the center line of the high frequency induction heating coil (4), and is moved toward and away from the levitating heating coil (4a) by a lifting mechanism such as a cylinder (not shown). It is supposed to be. In the case of the embodiment of FIGS. 2 to 6, the lower casting mold (2) is a bottomed cylindrical shape having a recess (21) in the upper surface opening, and a water cooling hole is formed inside. It is made of metal (generally copper having excellent thermal conductivity). Of course, a simple metal block having the above-described shape may be used. Further, the lower casting mold (2) may be a flat pressing portion (22) having a concave portion (23) for accommodating the molten metal (1b) at the center of the upper surface as shown in FIG. The optimum shape is adopted depending on the shape of the molded product (1c).

  On the other hand, the upper casting mold (3) is also disposed above and coincides with the center line of the high-frequency induction heating coil (4), and the high-frequency induction heating coil (4 The lower casting mold (2) is pressed against the upper surface through the center of the upper casting mold, and in the case of the embodiment of FIGS. A projection (31) to be inserted into the projection is provided. Of course, as described above, the molten metal (1b) in the concave portion (23) may be pressed by fitting into the concave portion (23) of the pressing portion (22) of the lower casting mold (2) as shown in FIG. The optimum shape for the shape of the molded product (1c) is adopted according to the lower casting mold (2). The upper casting mold (3) is also made of metal (generally made of copper having excellent thermal conductivity) in which water-cooling holes (not shown) are formed inside. Of course, it may be a simple block made of metal (for example, copper) having the above-mentioned shape.

  The raw material supply arm (5) is arranged beside the high-frequency induction heating coil (4), and up to a place that coincides with the center line of the high-frequency induction heating coil (4) with the amorphous alloy material (1a) placed on it. It moves horizontally and then rises to move the amorphous alloy material (1a) to the center of the high frequency induction heating coil (4). The material is generally a refractory material such as a ceramic having a higher melting point than the amorphous alloy material (1a). The return path will follow the reverse of the forward path. The raw material supply arm (5) is a combination mechanism of a known horizontal movement mechanism and lifting mechanism using a cylinder (not shown). The entire apparatus (A) is housed in a container (not shown) and is performed in an inert atmosphere filled with nitrogen or Ar during the operation. Of course, without the containment vessel, an inert atmosphere is formed by blowing the inert gas around the main part of the high frequency induction heating coil (4) and the lower casting mold (2), and the work is performed in this inert atmosphere. It may be.

  The amorphous alloy material (1a) used in the present invention is not particularly limited as long as it is an alloy having a supercooled liquid region and a composition capable of forming an amorphous phase (amorphous phase). Good. In this example, "Cu-Zr-Al system", "Cu-Zr-Ti system", "Ni-Nb-Ti-Zr-Co-Cu system", "Ti-Zr-Cu-Sn-Al system", "Zr-Cu system" -Ni-Al system "amorphous alloys.

  The operation of the apparatus (A) configured as described above will be described. First, the massive amorphous alloy material (1a) is placed on the raw material supply arm (5), and this is melted using a floating melting method (melting step). In this example, the amorphous alloy material (1a) is preliminarily degassed by first melting the base material of the alloy raw material in an arc melting furnace, and the additive material is mixed in the arc melting furnace to make a lump. This is the amorphous alloy material (1a) supplied to the raw material supply arm (5).

  Then, as described above, it is placed on the raw material supply arm (5) and moved horizontally and upward, and the massive amorphous alloy material (1a) is moved to the center of the high frequency induction heating coil (4). In this state, a high frequency alternating circular current (I1) is passed through the high frequency induction heating coil (4). Then, as shown in FIG. 3, upward magnetic field lines (shown by solid lines) are generated in the lower levitation heating coil (4a), and a lump that is a conductor sphere located above the lower levitation heating coil (4a). In the amorphous alloy material (1a), an eddy current (I2) in the opposite direction is induced, and the current (I1) and the eddy current (I2) repel each other to form a massive amorphous alloy material that is a conductor sphere ( The levitation force acts on 1a), lifts from the raw material supply arm (5), and stops when the gravity and the levitation force are balanced. At this point, the raw material supply arm (5) returns to the home position through the return path. A downward magnetic field line (shown by a solid line) is generated in the upper stabilizing coil (4b) to stabilize the stationary position of the amorphous alloy material (1a).

  As described above, an eddy current (I2) is induced in the bulk amorphous alloy material (1a), and the eddy current (I2) melts in a floating state and becomes spherical due to surface tension. By controlling the amount of the amorphous alloy material (1a) dissolved, the amount of current supplied to the high-frequency induction heating coil (4), its applied voltage, the frequency of the supplied current, etc., it is possible to melt while maintaining levitation. It becomes.

  After melting, in this embodiment, the lower casting mold (2) rises to just below the levitation heating coil (4a) and waits for hot water. In this state, by suppressing the power supplied to the high frequency induction heating coil (4) (for example, reducing the supply current to I3), the Lorentz force of the levitating heating coil (4a) against the molten metal (1b) is reduced, As shown in FIG. 4, the molten metal (1b) moves downward due to gravity and flows down, and flows into the lower casting mold (2) waiting immediately below. Immediately after this, the current supply is cut off, and then the upper casting mold (3) is operated to insert the protrusion (31) into the recess (21) and compress the molten metal (1b) in the recess (21). Cool quickly at the same time. By this pressurization, the dissolved gas in the molten metal (1b) is released out of the molten metal (1b). At the same time, the molten metal (1b) is rapidly cooled to become amorphous from the surface. These operations are performed in a short time.

  If the cooling rate is sufficiently high with respect to the thickness, the whole is made amorphous. Table 1 below is a comparison table of metal glass forming ability between the conventional casting method and the floating melting press method under the same cooling conditions. It is clear that the method of the present invention has a higher ability to form metallic glass.

  When cooling in the casting mold (2) is completed, the amorphous alloy molded product (1c) is taken out from the casting mold (2). The amorphous alloy molded product (1c) is cooled and solidified according to the shape of the cavity formed by the lower casting mold (2) and the upper casting mold (3), and after removing the mold, cutting excess parts, deburring, etc. Through this process, and if necessary, a process such as cleaning, polishing, and painting is obtained to obtain a finished product.

  In the melting process using such a floating melting method, impurities from the crucible are not mixed into the amorphous alloy material (1a), so that the alloy can be melted with high purity or high precision and an extremely high quality alloy is manufactured. be able to. In addition, since the molten amorphous alloy material (1a) does not take heat away from the crucible as in the past, the molten metal can be heated to a very high temperature, and unmelted refractory metal such as zirconium can be reliably prevented. . Moreover, it is useful for producing an alloy having a homogeneous structure by a stirring action with strong electromagnetic force. Furthermore, since oxygen, hydrogen, carbon, or the like is not required for heating, the furnace air can be freely selected, and it is useful for molding an ingot having no blowhole inside by vacuum heating or reduced pressure heating.

  The present invention has the disadvantages of the amorphous alloy molded product formed by the conventional method, that is, (1) nests are likely to occur, (2) it is difficult to cope with thick products, and the amorphous region is Narrow disadvantages such as (3) inability to form a free shape including a hollow body having a single-sided opening or a through-hole (in other words, poor formability) were eliminated, and its unique mechanical properties For this reason, it has become possible to expand into fields that could not be handled by conventional metals, further expanding the possibilities of metals.

Principle of the device of the present invention Schematic illustration before dissolution of the device of the present invention Schematic explanatory diagram at the time of dissolution of the apparatus of the present invention Schematic explanatory diagram at the time of tapping with the apparatus of the present invention Schematic explanatory diagram during pressurization and cooling of the device of the present invention 6 is an enlarged cross-sectional view of the mold portion of FIG. Perspective view of gears made by the method of the present invention The perspective view of the test piece created by the method of the present invention The perspective view of the board created by the method of the present invention Perspective view of stepped bar made by the method of the present invention Perspective view of a bar made by the method of the present invention Sectional view of a hollow member with a single-sided opening made by the method of the present invention Sectional view of a stepped block having a through hole made by the method of the present invention Plan view of deformed member created by the method of the present invention Sectional view during casting of the conventional method

Explanation of symbols

(1) Amorphous alloy
(1b) Amorphous alloy melt
(2) Lower casting mold
(3) Upper casting mold

Claims (3)

  A melting process for floating and melting an amorphous alloy, a pouring process for pouring the molten metal into a lower casting mold located below the molten metal of the amorphous alloy, and a lower casting by pressing the upper casting mold to the lower casting mold A method for forming an amorphous alloy, comprising: a pressure quenching step of pressing a molten metal in a mold.   A high frequency induction heating coil for floatingly melting an amorphous alloy, a lower casting mold that is disposed below the high frequency induction heating coil and receives the molten amorphous alloy melted by the high frequency induction heating coil, and a lower casting mold An apparatus for forming an amorphous alloy, comprising: an upper casting mold for pressing and quenching a molten metal in a lower casting mold with a press.   The high frequency induction heating coil is composed of an upper stabilization coil composed of a plurality of turns and a lower levitation heating coil composed of a plurality of turns, and the coil diameter gradually becomes smaller as it goes to the casting mold side. The apparatus for forming an amorphous alloy according to claim 2, wherein the apparatus is formed.