JP2000096197A - Forming method for amorphous alloy - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a forming method forming a forming material of an amorphous alloy having a supercooled liq. region by using a die for forming having a volume larger than that of the forming material and easily capable of making the ratio of the quantity of heat applied to the forming material and the die the same as the volume ratio of both. SOLUTION: A heat radiating source for simultaneously heating a forming material of an amorphous alloy having a supercooled liq. region and a die for forming the forming material and a shielding member for shealing a part of heat radiation to be applied to the forming material from the heat radiating source in such a manner that the ratio of the quantity of heat radiation to be applied to the forming material and the die for forming is made the same as the volume ratio of both.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method of forming an amorphous alloy, particularly an amorphous alloy having a supercooled liquid region.

[0002]

2. Description of the Related Art It has been known that an amorphous alloy having various compositions and shapes can be obtained by rapidly cooling an alloy in a molten state. An amorphous alloy having a specific composition becomes amorphous at a critical cooling rate of about 100 K / sec, so that a bulk material can be manufactured and a supercooled liquid state suitable for forming processing is exhibited. It has a supercooled liquid area. The supercooled liquid state is the glass transition temperature T _g
Implemented in the supercooled liquid temperature region between the crystallization starting temperature _{T X (T g <T X} ).

[0003] An amorphous alloy in a supercooled liquid state exhibits a syrup-like behavior called a glass transition behavior. That is, the viscosity is 10 ⁵ to 10 ¹² Pa · s, indicating a large fluidity, and a very small stress (usually 10 MPa
(a) and large deformation easily. Therefore, the amorphous alloy in the supercooled liquid state can be molded instantaneously, and can be supplied not only to every corner of the molding die but also to a portion having a fine shape of the die, and It is characterized in that a molded product with high shape accuracy can be manufactured.

Japanese Patent Application Laid-Open No. Hei 7-26354 (hereinafter referred to as Prior Document 1) discloses a method of heating an amorphous alloy by a high-frequency induction heating device. In the prior art document 1, crystallization of a molded product is performed by heating an amorphous alloy having a supercooled liquid region to a supercooled liquid temperature region at a heating rate of 100 K / sec or more by this heating method. Is stated to be blocked.

Japanese Patent Application Laid-Open No. Hei 8-176611 (hereinafter referred to as Prior Document 2) discloses that a core material of an amorphous alloy and a powder of the same amorphous alloy surrounding the core material are formed in a molding die. Disclosed is a method of disposing, heating a molding die from the outside by a heater, and heating the amorphous alloy inside the mold from the inside by applying a current between the core material and the molding die. Prior Document 2 describes that the amorphous alloy is rapidly heated and formed by this heating method to thereby prevent the structural change of the alloy.

[0006]

When forming an amorphous alloy in a supercooled liquid state, care must be taken to ensure that both the amorphousness of the formed product and the accuracy of the alloy shape are good. There must be. Factors affecting the amorphousness of the molded product include an integrated value between the temperature and the time of the amorphous alloy in the supercooling temperature range.

That is, in order to improve the degree of amorphousness of a molded product, an amorphous alloy having a supercooled liquid temperature region having a width of 50 K or more is formed as shown in FIG. The integral value S of the temperature difference (T−T _g ) between the temperature T of the alloy and the glass transition temperature T _g and the time t, that is, the equation shown in the following equation 1 is 3 × 10 ⁴ K · sec or less. It is known that it is desirable.

[0008]

(Equation 1)

Here, the integral is that the amorphous alloy is cooled after the forming process from time t ₁ when the amorphous alloy is heated and exceeds the glass transition temperature T _g and enters the supercooled liquid temperature region. performed for between equal to or lower than the glass transition temperature T _g and the time t ₂ exiting the supercooled liquid temperature region Te.

[0010] If the above conditions are not met, crystallization of the amorphous alloy will occur. That is, the amorphous alloy is crystallized and long-held supercooled temperature range even at a temperature region below the crystallization onset temperature T _X. The reason for the crystallization is that the constituent atoms of the alloy tend to move in the supercooling temperature range, so that if held in this temperature range for a long time, nuclei causing crystallization are generated and grow. In particular, in a temperature region close to the crystallization start temperature T _X in the supercooling temperature region, the viscosity coefficient of the amorphous alloy is further reduced, so that the mobility of constituent atoms is increased and the probability of nucleation is increased. .

A factor that affects the shape accuracy of a molded product is a temperature difference between an amorphous alloy and a molding die in a supercooling temperature region. That is, in order to improve the shape accuracy of the molded product, the temperature difference D between the temperature T of the amorphous alloy during the molding process and the temperature T ′ of the molding die is required.
It is known that the absolute value of = (T−T ′) is desirably 5K or less.

If the absolute value of the temperature difference D = (TT ′) during forming exceeds 5K, a temperature distribution occurs in the amorphous alloy during forming. When the temperature distribution occurs, distortion due to the forming process becomes non-uniform, and the degree of shrinkage between the amorphous alloy and the forming die differs during cooling after forming. As a result, distortion occurs on the processing surface of the molded product, and the shape accuracy is deteriorated.

In the above-mentioned prior art document 1, high-frequency induction heating is used as a heating means. When only an amorphous alloy is heated by high-frequency induction heating as shown in Patent Document 1, only the amorphous alloy rapidly rises in temperature. Therefore, the amorphous alloy reaches the molding temperature first, and the molding die reaches the molding temperature later. In order to reduce the value of the temperature difference D and obtain sufficient shape accuracy, the temperature T ′ of the molding die must be within 5 K of the temperature T of the amorphous alloy until the temperature T ′ of the amorphous alloy falls within 5 K.
It is necessary to keep the amorphous alloy at the forming temperature. As a result, the value of the integral value S of the above-mentioned amorphous alloy increases, and a sufficient degree of amorphousness cannot be obtained.

Even if both the amorphous alloy and the molding die are simultaneously heated by high-frequency induction heating, the volume of the molding die is usually 10 times or more larger than the volume of the amorphous alloy. Amorphous alloy has a higher heating rate. As a result, since the amorphous alloy reaches the forming temperature first, the value of the integral value S also increases as described above, and a sufficient degree of amorphousness cannot be obtained.

In the above-mentioned prior art document 2, as a heating means, for a molding die, heat transfer heating by a heater,
Electric heating is used for the amorphous alloy. Heat is not easily transferred from the heated mold to the amorphous alloy.
It is because the amorphous alloy before molding is only placed on the mold, even if the contact surface between the amorphous alloy and the mold is polished, This is because the substantial contact area is small and the efficiency of heat transfer is low. In addition, some amorphous alloys such as Zr-based and La-based amorphous alloys are easily oxidized, and thus need to be heated and formed under a reduced pressure of 10 ⁻² N / m ² or less. In such a reduced-pressure atmosphere, the efficiency of heat transfer to the amorphous alloy further decreases.

As described above, since the heat transfer from the molding die to the amorphous alloy is poor, even if the molding die is heated for a long time, the temperature T of the amorphous alloy becomes the temperature T ′ of the molding die. Difficult to reach.
That is, the mold first reaches the molding temperature. for that reason,
Again, both the integral value S and the temperature difference D cannot be reduced, and satisfactory values cannot be obtained for both the degree of amorphousness and the shape accuracy of the molded product.

On the other hand, energizing and heating the amorphous alloy is effective when the volume of the amorphous alloy is small. However, when the volume of the amorphous alloy is increased to a certain extent, a large amount of electric power is required, which is not practical. . For example, to heat a cylindrical amorphous alloy having a diameter of 24 mm to about 400 ° C.
It requires as much power as kVA, which is not practical.

Further, since the substantial contact area between the amorphous alloy and the molding die changes during the molding process, the electric resistance between the amorphous alloy and the molding die changes. When the electric resistance changes, the amount of heat generated by the heating also changes, so it is difficult to keep the temperature of the amorphous alloy constant.

[0019] In order to reduce both the integrated value S and the temperature difference D is the temperature T 'and the mold temperature T of the amorphous alloy reaches the glass transition temperature T _g at the same time, during the molding process It is necessary that the temperatures T and T 'do not fluctuate, respectively. In other words, the amorphous alloy and the molding die are T
It is necessary that the heating rates until reaching _g are the same. If the rate of temperature rise is the same, the temperature control of both during the molding process is also facilitated.

In order to match the temperature rising rate of the amorphous alloy with that of the molding die, it is sufficient to provide a difference in the amount of heat transferred to each of them so as to match the difference in conductivity and volume between the two. In actual forming processing of an amorphous alloy, the volume of the molding die is 10 times or more larger than that of the amorphous alloy, and the volume difference is larger than the difference in thermal conductivity. Therefore, the amount of heat transferred to the amorphous alloy may be made smaller than the amount of heat transferred to the molding die in accordance with the volume ratio between the amorphous alloy and the molding die. In order to reduce the amount of heat transferred to the amorphous alloy, a part of the amount of heat transferred from the heating means to the amorphous alloy may be cut off.

In the high-frequency induction heating disclosed in the above-mentioned prior art document 1, the magnetic field generated in the amorphous alloy is partially reduced in order to cut off a part of the amount of electric heat applied to the amorphous alloy. It is difficult.

In the heat transfer heating and the electric current heating described in the above-mentioned prior art document 2, the heating atmosphere and the change in the contact area between the amorphous alloy and the forming mold during the forming process are considered. Since it is easily affected, it is difficult to adjust the heating state so as to block a part of the heat applied to the amorphous alloy.

It is conceivable to use a plurality of heating means to provide a difference in the amount of heat transferred to the amorphous alloy and the molding die. For example, an amorphous alloy is heated by high-frequency induction heating, and a molding die is heated by heat transfer with a heater.
However, heating the amorphous alloy and the mold using a plurality of heating means causes a problem that temperature control during molding is complicated.

That is, an object of the present invention is a molding method for molding a molding material made of an amorphous alloy having a supercooled liquid region using a molding die having a larger volume than the molding material. An object of the present invention is to provide a molding method capable of easily making the ratio of applied heat equal to the volume ratio of both.

[0025]

In order to solve the above-mentioned problems, the present invention provides a method of simultaneously applying heat radiation to a molding material and a molding die made of an amorphous alloy from a heat radiation source. And Then, a shielding member for shielding a part of the heat radiation is arranged between the heat radiation source and the molding material. By adjusting the total emissivity of the shielding member,
The ratio of the heat radiation given to both, that is, the ratio of the amount of heat, can be easily made the same as the volume ratio of both.

In particular, when the volume ratio between the molding material and the molding die is 1:10 to 1: 100, a material having a total emissivity of 0.01 to 0.3 at the molding temperature is used. It has been experimentally found that when used as a shielding member, the heat radiation given to the molding material and the molding die can be made the same as the volume ratio of both.

That is, according to the present invention, a molding material made of an amorphous alloy having a supercooled liquid region is converted into a supercooled liquid temperature region by using a molding die having a larger volume than the molding material. A method for molding an amorphous alloy which is molded at a molding temperature, comprising: a heat radiation source for simultaneously applying heat radiation to both the molding material and the molding die to raise the temperature to the molding temperature; And a shielding member for shielding a part of the heat radiation applied to the molding material from the heat radiation source so that the ratio of the amount of heat radiation applied to the molding die is equal to the ratio of the volumes of the two. Is provided.

In the present invention, when the volume ratio between the molding material and the molding die is 10 to 100, the shielding member has a total emissivity at the molding temperature of 0.01 to 0.3.
It is preferred to be composed of the following materials.

In the present invention, when the volume ratio of the molding material to the molding die is 10 to 100, the shielding member transmits at least a part of infrared rays and has a total emissivity at the molding temperature. Comprises a first member made of a material having a ratio of 0.8 or more, and a second member formed on the first member and having a total emissivity at the molding temperature of 0.01 to 0.3. Is preferably performed.

[0030]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
In the present invention, heat radiation is simultaneously applied from a heat radiation source to both a molding material made of an amorphous alloy and a mold for molding the molding material. Heat radiation is applied to both of them at the same time to raise the temperature to the forming temperature, thereby forming the forming material of the amorphous alloy. The molding temperature is set in the supercooled liquid temperature range of the amorphous alloy described below.

As the amorphous alloy, an alloy having a supercooled liquid region is used. As the width of the supercooled liquid temperature area,
For example, it is 50K or more. Examples of such an amorphous alloy include Zr ₅₅ Cu ₃₀ Al ₁₀ Ni ₅ and Zr ₆₀ Cu ₃₀ A.
_{l 10, Pd 40 Cu 30 P} 20 Ni 10, La 55 Al 25 Cu 10 N
i ₁₀ , and Ti ₅₀ Cu ₃₀ Ni ₁₀ Co ₁₀ .

In these composition formulas, the appended numbers for each element symbol indicate the value of atomic%. For example, Zr ₅₅ Cu ₃₀
Al ₁₀ Ni ₅ indicates that Zr is 55 atomic%, Cu is 30 atomic%, Al is 10 atomic%, and Ni is 5 atomic%.

Usually, the supercooled liquid temperature range of the amorphous alloy is about 500 K to about 800 K including the above-mentioned amorphous alloy.
K is distributed over the temperature range. For example, Zr ₅₅ Cu ₃₀ A
The supercooled liquid temperature range of l ₁₀ Ni ₅ is 691K and 777
It is between K. That is, the glass transition temperature T _g is 691
K, the crystallization start temperature T _X is 777K. As described above, the molding temperature is set within this supercooled liquid temperature range.

Examples of the shape of the amorphous alloy molding material include a columnar shape having a diameter of about 5 to 6 mm or less. When the amorphous alloy in the supercooled liquid state is cast into a cylindrical shape, the maximum diameter of the amorphous alloy cast as an amorphous phase is about 5 to 6 mm. When cast into a cylindrical shape exceeding this diameter, a crystal phase is precipitated. Therefore, when manufacturing a columnar amorphous alloy having a diameter exceeding about 5 to 6 mm, a columnar amorphous alloy having a diameter of about 5 to 6 mm or less produced by casting or the like is used for forming. It is necessary to mold using a mold.

The shape of the molding die is, for example, 16 mm in diameter.
and a columnar shape having a height of 30 mm and the like. As the surface roughness of the molding surface of the molding die, for example, Rmax
0.1 μm or less. The mold for molding usually has a larger volume than the molding material of the amorphous alloy. The volume ratio between the molding material and the molding die is, for example, 1:10 to 1:
For example, 100.

Examples of the material for forming the molding die include metals such as SUS420J2. Examples of the heat radiation source include a heat radiation type heating device such as a heater. As a characteristic of the heater, for example, the maximum heat radiation energy per unit area is 5 W / c.
m ² , the wavelength of the maximum radiant energy is about 3 μm, and 85% or more of the radiant energy is infrared light having a wavelength of 0.7 to 100 μm.

In the present invention, when heat is applied to the molding material and the mold of the amorphous alloy at the same time and heated, the heat applied from the heat radiation source to the molding material is applied between the molding material and the heat radiation source. A shielding member for shielding a part of the radiation is arranged.

The arrangement relationship among the molding material, the molding die, the heat radiation source, and the shielding member is as follows, for example. For example, in the case of press-forming an amorphous alloy, for example, a pair of cylindrical press-forming dies arranged vertically, a molding material disposed between the press-forming dies, so as to surround the molding material. There are a shielding member composed of a band-shaped shielding plate disposed around, a press molding die, a molding material, and a plurality of heat radiation sources arranged at equal intervals around the periphery so as to surround the shielding member.

The material for forming the shielding member is not particularly limited as long as it is a material capable of shielding heat radiation.
Preferably, the material is 0.3. In other words, it is preferable that the material has a total emissivity of 0.01 to 0.3 in a supercooled liquid temperature region where the molding temperature is set (as described above, a temperature range of about 500 K to about 800 K).

The emissivity of a substance is defined as a ratio (E (λ) / E _o (E (λ) / E _o (λ)) of the thermal radiation energy E (λ) emitted from the substance to the thermal radiation energy E _o (λ) emitted from the black body. λ))
It is. The emissivity is a physical property value that changes depending on the material, temperature, surface roughness, radiation wavelength, and the like of the substance. Here, a black body is defined as a substance that gives a maximum amount of thermal radiation energy.

The total emissivity of a substance is defined as the quantity I expressed by the following equation (2) obtained by summing the thermal radiation energy E (λ) radiated by this substance for all wavelengths, It is defined as the ratio (I / I _o ) to the quantity I _o given by the following equation (3), which is a sum of the radiated thermal radiation energy E _o (λ) for all wavelengths.

[0042]

(Equation 2)

[0043]

(Equation 3)

The larger the emissivity and the total emissivity of the shielding member, the greater the heat radiation, that is, the amount of heat transmitted from the heat radiation source to the molding material of the amorphous alloy. When the emissivity and the total emissivity of the shielding member are both 1.0, the heat radiation from the heat radiation source is given to the molding material without any loss. Conversely, the smaller the emissivity and the total emissivity of the shielding member, the smaller the amount of heat radiation transmitted from the heat radiation source to the molding material.

By using a shielding member made of a material having a total emissivity of 0.01 to 0.3, when the volume ratio of the molding material to the molding die is 1:10 to 1: 100, the heat radiation source From the ratio of the amount of heat radiation given to the molding material and the mold for molding,
It can be the same as the volume ratio of both.

As a material having a total emissivity of 0.01 to 0.3, for example, a metal material such as chromium, platinum, aluminum, copper, nickel, and stainless steel whose surface is polished may be mentioned.

Chromium has, for example, a total emissivity of 0.19 at a temperature of 720K. Platinum has a temperature of 7
The total emissivity at 20K is 0.08. The melting point of the material forming the shielding member, the upper limit of the supercooled liquid temperature region of the amorphous alloy which is a molding material (i.e., the crystallization onset temperature T _X) is preferably at least. Since the molding temperature of the molding material is in the supercooled liquid temperature region, by the melting point of the shielding member is not less than T _X, it is possible to prevent the shield member is melted during the molding of the molding material.

Examples of the material having such a melting point include the materials described above. That is, for example,
Chromium (melting point 2166K), platinum (melting point 2045K),
Aluminum (melting point 933K) copper (melting point 1358K),
Nickel (1728K), stainless steel (melting point> 100
0K).

The shielding member has a thickness of about 1 to about 5
It is preferably 00 μm. If the thickness exceeds about 500 μm, it takes some time for the shielding member to absorb heat from the heat radiation source and reach a thermal equilibrium state. That is,
Immediately after starting the heating of the molding material, the shielding member is not in thermal equilibrium. Therefore, immediately after the heating is started, the amount of heat radiation transmitted to the molding material temporarily becomes extremely smaller than a desired value, and is not equal to the volume ratio between the molding material and the molding die. Therefore, the rate of temperature rise of the amorphous alloy is smaller than that of the molding die.

When the thickness is less than about 1 μm, the strength is insufficient for use as a shielding member. Even if the thickness of the shielding member is 1 μm or more, if the thickness is several tens μm or less, the strength is low, so that the handling of the shielding member becomes inconvenient in the actual forming work.

In this case, in order to secure the strength, it is preferable to use a shielding member having a structure in which a second member for shielding is formed on a first member for supporting. The second member for shielding has characteristics similar to those of the above-described shielding member.

The first supporting member is preferably formed of a material having a total emissivity of 0.8 or more at the molding temperature and transmitting at least a part of the wavelength of infrared rays. .

When the total emissivity is 0.8 or more, heat radiation from a heat radiation source can be sufficiently transmitted. In addition, since the heat radiation from the heat radiation source contains the largest amount of radiation in the infrared region, the use of a material that is transparent to at least a part of the wavelength of infrared light allows sufficient heat radiation from the heat radiation source. Can be transmitted. Here, the infrared ray means an electromagnetic wave having a wavelength of about 0.7 to about 100 μm.

Examples of the material having such characteristics include a glass material such as quartz glass. Quartz glass has, for example, a total emissivity of 0.85 at a temperature of 720 K, and is transparent to electromagnetic waves including infrared rays having a wavelength of 0.2 to 4 μm.

The first member for supporting sufficiently transmits the heat radiation from the heat radiation source without blocking it due to the above-mentioned characteristics. As a result of the first member sufficiently transmitting the heat radiation, only the second member for shielding blocks the heat radiation,
By adjusting only the total emissivity of the second member for shielding, the amount of heat applied to the molding material can be easily adjusted.

The melting point of the material forming the first member for supporting, like the material for the shielding member, should be equal to or higher than the crystallization start temperature T _X of the molding material so as not to melt during molding of the molding material. preferable. Such materials include, for example,
Glass materials such as the above-mentioned quartz glass (melting point 1900K) and the like can be mentioned.

The thickness of the supporting first member is preferably, for example, 1 to 3 mm. With this thickness, sufficient strength can be given to the entire shielding member. The formation of the second member for shielding on the first member for support can be performed by a film forming technique such as vapor deposition or sputtering. With these techniques, the second member can be formed in close contact with the first member.

As described above, with the structure in which the second member for shielding is formed on the first member for support, it is possible to realize a shielding member having a sufficient effect as well as an effect of shielding heat radiation.

In the present invention, as described above, since the amount of heat applied to the amorphous alloy molding material can be adjusted only by adjusting the emissivity of the shielding member, the amount of heat applied to both the molding material and the molding die is reduced. The ratio can easily be made equal to the volume ratio of the two.

By making the ratio of the amount of heat radiation the same as the volume ratio, the amorphous alloy and the molding die can reach the supercooled liquid temperature region at substantially the same rate of temperature rise. As a result, since both the integral value S and the temperature difference D can be reduced, good values can be obtained for both the degree of amorphousness and the shape accuracy of the molded product.

It should be noted that reaching at substantially the same heating rate means that the amorphous alloy and the molding die need to reach the lower limit of the supercooled liquid temperature range (ie, the glass transition temperature T _g ). This means that the difference in the time is within 30 seconds.

Next, a molding apparatus for carrying out the present invention will be described. FIG. 1 shows a molding apparatus according to a first embodiment suitable for carrying out the present invention. FIG. 1A is a schematic sectional view, and FIG. 1B is a schematic top view. In addition,
In FIG. 1B, a punch 14 described later is omitted.

The molding apparatus of the first embodiment can be used, for example, for molding a molding material of an amorphous alloy to produce a plane mirror or the like. The molding apparatus according to the first embodiment includes a molding die 10, a heat radiation section 30, and a shielding section 50. These are all located in a vacuum chamber (not shown). An exhaust device (not shown) such as a vacuum pump for reducing the pressure in the decompression chamber is connected to the decompression chamber. The pressure in the decompression chamber is set to, for example, 10
^The pressure is reduced to ^-3 N / m ² or less.

The molding die 10 comprises, for example, a pair of an upper die 11 and a lower die 12 which are vertically arranged opposite to each other. As described above, the shape of each mold is, for example, a cylindrical shape having a diameter of 16 mm and a height of 30 mm.

The lower surface of the upper die 11 is a molding surface 11a, and the upper surface of the lower die 12 is a molding surface 12a. A molding material 13 is arranged between the molding surfaces 11a and 12a. The upper surface of the upper mold 11 is connected via a punch 14 to an air cylinder (not shown) outside the decompression chamber.
The punch 14 air-tightly penetrates a decompression chamber (not shown). The upper mold 11 can move up and down by the air cylinder. The upper mold 11 is lowered onto the molding material 13 to press and mold the molding material 13 when all of the upper and lower dies 11, 12 and the molding material 13 reach a desired molding temperature.

The lower mold 12 is fixed to the floor 25 of the decompression chamber via the pedestal 15. The heat radiation section 30 includes a heat radiation type heater 31 and a heater 31 each having a resistance wire covered with a quartz tube.
Is fixed to the floor 25 of the decompression chamber.

The shielding unit 50 includes a shielding plate 51 for shielding heat radiation from the heater 31 and a shielding plate 5.
1 comprises a fixing jig 71 for fixing the fixing jig 1. Shielding plate 51
Is a mold 1 surrounding the molding material 13.
It is installed around 1 and 12. The shielding plate 51 is made of, for example, a rectangular chrome foil having a thickness of 15 μm, a width of 25 mm, and a length of 7 mm, which is rounded into a cylindrical shape. Shielding plate 51
Is installed, for example, such that the center of the molding material 13 is arranged at the center of the cylinder.

FIG. 2 is a schematic sectional view showing an example of the fixing jig 71. The fixing jig 71 shown in FIG. 2 is a fixing plate 54 made of an L-shaped SUS 302 having a screw hole 52 and a through hole 53.
And a spacer 56 made of SUS302 having a through hole 55
Consists of By sandwiching the lower end of the shielding plate 51 between the fixing plate 54 and the spacer 56 and screwing the screw 57 into the screw hole 52 through the through hole 55, the shielding plate 51 is fixed to the fixing plate 5.
Fixed to 4. Further, by aligning the through hole 53 of the fixing plate 54 with the screw hole 58 in the floor surface 25 of the decompression chamber and screwing the screw 59 into the screw hole 58 through the through hole 53, the lower part of the fixing plate 54 is It is fixed to the floor surface 25. Thus, the shielding plate 51 is fixed to the floor surface 25 via the fixing jig 71.

FIG. 3 shows another example of the fixing jig 71. The fixing jig 71 shown in FIG. 3 includes two spacers 56, each of which has a through hole 55.
Further, a screw hole 60 is provided on a side surface of the upper die 11 or the lower die 12. By sandwiching the lower end of the shield plate 51 between the two spacers 56 and screwing the screws 57 into the screw holes 60 through the through holes 55, the shield plate 51 is directly fixed to the upper mold 11 or the lower mold 12. As the spacer 56, a sufficiently thick spacer is used so that the shielding plate 51 is fixed away from the upper die 11 so as not to hinder the vertical movement of the upper die 11.

As shown in FIG. 1B, the heater 30 and the fixing jig 71 are arranged at four locations so as to surround the upper and lower dies 11 and 12. The distance between the surface of one heater 31 and the surfaces of the upper and lower dies 11, 12 is, for example, about 50 mm.

The temperature T ₁ ′ of the upper mold 11 is determined by the temperature of the non-through hole 1 provided on the surface opposite to the molding surface 11 a of the upper mold 11.
The measurement can be performed by the thermocouple 17 inserted in the thermocouple 6.

The temperature T ₂ ′ of the lower mold 12 is determined by the temperature of the non-through hole 1 provided on the surface opposite to the molding surface 12 b of the lower mold 12.
The measurement can be performed by a thermocouple 19 inserted in 8.

If necessary, the temperature T of the molding material 13 of the amorphous alloy is adjusted to the through hole 61 provided in the shielding plate 51.
Can be measured by a thermocouple 21 inserted into a non-through hole 20 provided in the molding material 13 through the through hole. In a normal molding process, the non-through hole 20 is formed in the molding material 13.
The temperature T of the molding material 13 is not measured because the molded article is damaged if the above is provided. However, when setting conditions for molding is performed in advance, the temperature T of the molding material 13 is measured by a thermocouple 21 inserted into a through hole 20 provided in the molding material 13.

FIG. 4 is a schematic side view showing a second embodiment of a molding apparatus suitable for carrying out the present invention. Second
The molding apparatus according to the embodiment has the same configuration as that of the apparatus according to the above-described first embodiment except that the shielding unit 50 is different.

The shielding section 50 of this device is composed of a supporting member 81 made of, for example, quartz glass and a shielding plate 51 made of platinum or the like formed on the quartz glass 81 by vapor deposition. The quartz glass 81 has, for example, an outer diameter of 25 mm and a height of 65 mm.
mm and a cylindrical shape with a thickness of 2 mm.

The shielding plate 51 is formed on the quartz glass 81 so as to surround the molding material 13. The shielding plate 51 has a width of 7 along the outer diameter surface of the quartz glass 81, for example.
It was made of platinum having a thickness of 5 μm and deposited in a strip of mm. The shielding plate 51 is vapor-deposited on the quartz glass 81 so that the center of the molding material 13 is disposed at the center of the band, for example.

Since the quartz glass 81 can be set upright in the longitudinal direction so that the molding die 10 is arranged inside the hollow cylinder, the fixing jig 71 is not required. The thermocouple 17 for measuring the temperature T ₁ ′ of the upper mold 11 passes through the upper end opening of the quartz glass 81 and passes through the non-through hole 1 of the upper mold 11.
6 is inserted.

The thermocouple 19 for measuring the temperature T ₂ ′ of the lower mold 12 is inserted into the non-through hole 18 of the lower mold 12 through a through hole 82 provided below the quartz glass 81. Thermocouple 21 for measuring temperature T of molding material 13
Passes through the non-through hole 20 of the molding material 13 through a through hole 83 provided through the quartz glass 81 and the shielding plate 51.
Has been inserted.

[0079]

EXAMPLE Using the apparatus shown in FIG. 1, a molding material of an amorphous alloy having a diameter of 5 mm was molded to produce a plane mirror having a diameter of 10 mm. As the molding material 13, a cylindrical material having a diameter of 5 mm and a height of 5 mm was used. This molding material 13
The volume ratio between the upper mold 11 and the lower mold 12 is about 1:
60.

As the molding material 13, a bulk amorphous alloy Zr ₅₅ Cu ₃₀ Al ₁₀ Ni ₅ was used. As described above, the glass transition temperature T _g of this amorphous alloy is 691 K,
The crystallization start temperature T _X is 777K.

The molding material 13 is applied to the molding surfaces 11 a and 12
It was placed between the upper and lower dies 11 and 12 so as to be in contact with a.
After placing the molding material 13, the shielding plate 51 is moved to the molding material 1.
3 was fixed by a fixing jig 71. Shielding plate 51
Was fixed, and the pressure in the decompression chamber was reduced to 10 ⁻³ N / m ² or less.

While the pressure was reduced, the molding material 13 and the molding die 10 were heated by the heater 31 to raise the temperature.
The temperatures of the molding material 13, the upper mold 11 and the lower mold 12 during the heating were measured by thermocouples 21, 17 and 19, respectively.

FIG. 5 shows an example of the measurement results of the temperature. The horizontal axis in FIG. 5 indicates the time (second) since the start of the temperature rise,
The vertical axis represents the temperature T of the molding material 13 and the temperature T of the upper mold 11.
The measurement result of ₁ 'is shown.

As shown in FIG. 5, when the molding material 13 is heated, the temperature T of the molding material 13 is changed to the glass transition temperature T _g.
(691K), that is, the time from the start of heating to time t ₁ is about 1500 seconds (25
Min).

The temperature T of the molding material 13 is the glass transition temperature T
Until the temperature reached g, the temperature difference between the temperature T and the temperatures T ₁ ′ and T ₂ ′ of the upper and lower dies 11 and 12 was ₁₅ K at the maximum.

The time from when _{one of the} temperatures T, T ₁ ′ and T ₂ ′ reaches the glass transition temperature T _g to when the remaining two temperatures both reach the glass transition temperature T _g. Was about 5 seconds, much less than 30 seconds. That is, as described above, it was confirmed that the molding material 13 of the amorphous alloy and the molding dies 11 and 12 reached the supercooled liquid temperature region at substantially the same heating rate.

The temperature rise from the glass transition temperature T _g to the target forming temperature (set to 720 K in this embodiment) is about 30 ° C.
Performed at 0 seconds. After confirming that the temperature difference between the temperatures T, T ₁ ′, and T ₁ ′ is within 5 K and that the average value of these three temperatures has reached the target molding temperature (720 K), the air cylinder ( (Not shown), the punch 1 is driven.
The upper mold 11 connected to 4 was lowered, the molding material 13 was pressed at a pressure of 30 MPa, and was pressed and held for 10 minutes to perform molding.

As for the temperature T of the amorphous alloy 13 during forming, the maximum value is 723.6 K, the minimum value is 720.4 K, and the average value is 7
It was 21.8K. T, T ₁ ′, and T during molding
The temperature difference between ₂ 'was a maximum of 3.6K. That is,
It was confirmed that the absolute value of the above-described temperature difference D = (TT ′) was 5K or less.

The time t _{1 when} the temperature T of the amorphous alloy 13 reaches the glass transition temperature T _g is 1520 seconds, and the time t ₂ when the temperature T becomes equal to or lower than the glass transition temperature T _g after the forming is completed. Was 1770 seconds. From these measurement results, the integral S was calculated to be 2.7 × 10 ⁴ K · sec.
It was confirmed that S was 3 × 10 ⁴ K · sec or less.

After the molding was completed, the upper mold 11 was raised and the heating by the heater 31 was stopped. After the molded product was sufficiently cooled, the inside of the decompression chamber was set to the atmospheric pressure, and the molded product was taken out.

As described above, in this embodiment, the conditions necessary for improving the degree of amorphousness and the shape accuracy of the molded product, that is, the absolute value of the temperature difference D = (TT ′) is 5K or less. And that the integral value S is 3 × 10 ⁴ K · sec or less.

The molded product thus obtained had an amorphous degree of 90% or more. Regarding the shape accuracy, the surface roughness Rmax was 0.1 μm or less, and the surface accuracy was 0.2 μm or less. These were all satisfactory values.

[0093]

As described above, according to the present invention, a molding method for molding a molding material made of an amorphous alloy having a supercooled liquid region using a molding die having a larger volume than this molding material is used. Thus, a molding method is provided which can easily make the ratio of the amount of heat given to both the same as the volume ratio of both. As a result, since both can be formed after reaching the supercooled liquid temperature region at the same heating rate, it is possible to obtain a molded product excellent in both the degree of amorphousness and the shape accuracy.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view and a top view showing a first embodiment of a molding apparatus according to the present invention.

FIG. 2 is a schematic sectional view showing an example of a fixing jig of the molding apparatus according to the present invention.

FIG. 3 is a schematic sectional view showing another example of a fixing jig of the molding apparatus according to the present invention.

FIG. 4 is a schematic sectional view showing a second embodiment of the molding apparatus according to the present invention.

FIG. 5 is a diagram showing a result of measuring a temperature change in the example of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Molding die 11 ... Upper mold 12 ... Lower mold 11a, 12a ... Molding surface 13 ... Molding material of amorphous alloy 14 ... Punch 15 ... Pedestal 16, 18, 20 ... Non-through hole 17, 19, 21 ... Thermoelectric Pair 25: Floor surface 30: Heat radiation section 31: Heat radiation type heater 32: Fixing column 33: Fixing table 50: Shielding section 51: Shielding plate 52, 58, 60: Screw hole 53: Through hole 54: Fixing plate 55 ... through hole 56 ... spacer 57, 59 ... screw 61, 82, 83 ... through hole 71 ... fixing jig 81 ... quartz glass

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) C21D 1/34 C21D 1/34 S C22F 1/18 C22F 1/18 E HA // C21D 1/00 112 C21D 1 / 00 112F

Claims (3)

[Claims] 1. A non-molding method comprising molding a molding material comprising an amorphous alloy having a supercooled liquid region at a molding temperature in a supercooled liquid temperature region using a molding die having a larger volume than the molding material. A method of forming a crystalline alloy, comprising: a heat radiation source for simultaneously applying heat radiation to the molding material and the molding die to raise the temperature to a molding temperature; And a shielding member for shielding a part of the heat radiation applied from the heat radiation source to the molding material so that the ratio of the applied heat radiation amounts to the volume ratio of the two. 2. The method according to claim 1, wherein the volume ratio of the molding material to the molding die is 1
2. The method according to claim 1, wherein in the case of 0-100, the shielding member is made of a material having a total emissivity at the molding temperature of 0.01-0.3. 3. The volume ratio of the molding material to the molding die is 1
In the case of 0 to 100, the shielding member is formed on a first member made of a material that transmits at least a part of infrared rays and has a total emissivity of 0.8 or more at the molding temperature, and a first member formed on the first member. And the total emissivity at the molding temperature is 0.01 to
2. The method of claim 1 comprising a second member made of 0.3 material.