JP2008231569A - Manufacturing method of precision parts - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive and industrial method for producing an ultra-small precision metal part by precision die set processing of volume-controlled metal glass powder.
In order to obtain a precision part shape, a metal glass alloy powder is inserted into a precision machined die, and the metal glass alloy powder is pressed with a punch while being maintained at a glass transition temperature or more and a crystallization temperature or less. In the process of obtaining a precision part, the precision part is characterized in that the powder is measured and inserted so that the volume of the metal glass alloy powder inserted into the die is the same as the volume of the precision part after pressure molding. Manufacturing method.
[Selection] Figure 1

Description

  In recent years, with the development of semiconductor micromachining technology, development of micromachines, which are mechanical elements for medical and micromotors, according to component processing, and development of MEMS (Micro Electro Mechanical Systems) that integrate them with semiconductor technologies It is flourishing. In these precision parts, there is a strong demand for metal parts to achieve high durability and low cost, and further miniaturization and high precision are required to cope with future medical advancement and equipment refinement. Accordingly, there is a need for a method for economically manufacturing ultra-precision metal parts.

  As a conventional manufacturing method of micromachines and precision machine parts, for example, as disclosed in JP-A-6-194432 (Patent Document 1), a prepolymer having an ethylenically unsaturated bond and an ethylenically unsaturated compound A method of manufacturing bulk metal parts by electroforming after forming an electroless plating film on a matrix in which a liquid photosensitive resin made of monomer is cured, and combining X-ray lithography using electroluminescence and electroforming A method of creating a precision part from a matrix by a method (LIGA) has been proposed. However, in these methods, molds made of resin or LIGA for taking out electroformed parts cannot be reused because they are melted and removed by acid or the like, and there is a problem that the mass production process is complicated and expensive. It was.

In recent years, it has been proposed to use metallic glass as a precision processing material for these problems. Metallic glass is an alloy that can produce an amorphous structure without supercooling the molten metal, and is characterized by a clear glass transition temperature and crystallization temperature when the amorphous metallic solid is heated. In order to precisely process a metallic glass, it is important to process it in a temperature range excellent in viscous fluidity above the glass transition temperature and below the crystallization temperature. For example, “Metal” vol. 75 (2005) No. 2 As disclosed in “Application of Bulk Metallic Glass” (Non-Patent Document 1), it is disclosed in a process for producing a microgear by injection molding or in JP-A-11-71602 (Patent Document 2). In addition, a process has been proposed in which a metal mold is filled with a metallic glass alloy powder and then subjected to pulsed discharge sintering to obtain a part having precise irregularities.
Japanese Patent Laid-Open No. 6-194432 JP-A-11-71602 JP 2002-155305 A JP 2006-193775 A “Metal” vol. 75 (2005) No. 2 “Application of bulk metallic glass”

  However, in the method of Non-Patent Document 1, since a bulk metallic glass alloy is formed by injection molding, a step for cutting out a precision part after processing from the bulk and a finishing process of the cut end face are necessary. There is. Further, the method disclosed in Patent Document 2 applies a conventional powder metallurgy method in which metallic powder is manufactured by filling a mold with a powder having a random particle size and sintering by pulse discharge sintering. The present invention relates to a manufacturing method intended to give fine irregularities to a sufficiently thick bulk molded product, and cannot be applied to the mass production process of ultra-small precision metal parts as described above.

In order to solve the above-mentioned problems, the inventors have intensively developed, and as a manufacturing method of ultra-small precision metal parts, the volume is controlled to be the same as the part volume after forming. The metal glass alloy powder is used as a raw material, the powder is filled into a precision-processed die, and is pressed in a temperature range from the glass transition point to the crystallization temperature to precisely form ultra-small parts with high yield. In addition, since the die can be used repeatedly, the present inventors have found a method that can greatly reduce the cost compared to the conventional method.
That is, the present invention has been made in view of the above circumstances, and provides an inexpensive and industrial method for manufacturing an ultra-small precision metal part by precision die-set processing of a volume-controlled metal glass powder. .

The gist of the invention is that
(1) In order to obtain a precision part shape, a metal glass alloy powder is inserted into a precision machined die, and the metal glass alloy powder is pressed with a punch while maintaining the glass transition temperature to the crystallization temperature. In the step of obtaining a part, manufacturing of a precision part characterized by measuring and inserting the powder so that the volume of the metal glass alloy powder inserted into the die is the same as the volume of the precision part after pressure forming Method.
(2) In the method described in (1) above, two or more kinds of metal glass alloy powders having different compositions in which the total volume of the metal glass alloy powders of each composition is the same as the volume of the precision part after pressure forming are combined. It is in the manufacturing method of the precision component characterized by inserting in a die together.

  As described above, according to the present invention, ultra-precision parts can be mass-produced at low cost by die processing, and there is an extremely excellent effect that no unnecessary part is generated and no post-processing is required by volume control of the material.

The present invention will be described in detail below.
A metal glass alloy is most suitable as a processing material for obtaining the ultra-precise metal part intended by the present invention. This alloy is excellent in viscous fluidity when processed in the range of the glass transition temperature or more and the crystallization temperature or less, and exhibits superplastic deformation behavior. Due to its characteristic deformation behavior, it is possible to manufacture parts having complicated surfaces and shapes because it fills even fine parts of a die precisely processed with a press pressure much lower than that of ordinary metal.

  As typical components of the metallic glass alloy according to the present invention, Fe-based: Fe- (Al, Ge)-(P, C, B, Si, Ge), (Fe, Co)-(Si, B) -Nb Ni system: Ni- (Zr, Hf, Nb) -B, Ni-Nb- (Ta, Ti, Sn, Zr), Zr system: Zr-Al-TM (TM: Group V to VIII transition metal), Cu System: Cu-Zr-Al- (Pd, Ag, Au) and the like. However, (Fe, Co)-(Si, B) -Nb exemplified as an Fe group is a system in which a part of Fe may be substituted with Co. These have excellent properties such as high strength, low Young's modulus, high corrosion resistance, high magnetic permeability, excellent moldability and excellent castability, and surface smoothness.

  By utilizing the above-mentioned characteristics, in the present invention, the volume of a part after press molding is calculated in advance, a metallic glass powder having the same volume is prepared, inserted into a die, and then molded, Finishing processing such as cutting and polishing after molding, which is necessary when processing metal parts by injection molding, is not necessary. That is, the volume of the part, which is the final product after press molding, is calculated in advance, and a metal glass powder having the same volume as the previously calculated volume is inserted into the die as a raw material, and the temperature is not lower than the glass transition temperature and not higher than the crystallization start temperature The volume after press mold processing is controlled. This metallic glass can be plastically flow filled into fine irregularities, and since the total volume is controlled, no unnecessary portion is generated. Moreover, the combination of the component powder which has a function according to a component site | part is attained.

  Moreover, as a manufacturing method of the metal glass powder mentioned above, the manufacturing method of the metal particle with uniform particle diameter which is proposed by Unexamined-Japanese-Patent No. 2002-155305 (patent document 3), or Unexamined-Japanese-Patent No. 2006-193775, for example. As proposed in the publication (Patent Document 4), the molten metal is dropped as a continuous solid flow, the falling flow is divided by applying electromagnetic force, and the divided molten metal itself A method for producing metal particles can be applied, for example, a metal particle having a relatively large particle size can be obtained by spheroidizing by the surface tension of the material.

  That is, Patent Document 3 described above is a method in which the inside of a crucible containing molten metal is balsically pressurized by a piezoelectric actuator, and the molten metal is ejected while being divided into droplets. In this method, the molten metal flow is divided by applying electromagnetic force to the molten metal, and both of the molten metal droplets solidify spherically by surface tension while naturally falling in an inert atmosphere, and the spherical metal has a constant particle size. A powder can be produced. According to these methods, the particle diameter (= powder volume) obtained by controlling the nozzle diameter, pulse pressure, and electromagnetic force can be controlled, and can be used as the material of the present invention.

  As the metal glass powder used in the present invention, it is desirable to use alloy particles having the same volume as the part volume after pressing, but it is possible to combine powders having the same composition and different volumes, or combining powders having different compositions. It is also possible to adjust the total volume of the powders to the same volume as the part. Especially in the latter case, if the functions required at each part in the part such as hardness, magnetic properties, corrosion resistance, etc. are different, a composite functional part is formed by arranging a powder suitable for the function and simultaneously performing molding and firing. It becomes possible.

  Moreover, as a raw material of the mold used in the present invention, amorphous carbon, heat resistant glass and quartz glass excellent in heat resistance are preferable. Methods for processing these carbon and glass as precision molds include FIB (focused ion beam), laser, mechanical grinding, and the like, which are selected according to the shape and material. Furthermore, it is also possible to produce a bulk metal mold by electroforming a mother mold made of LIGA or a photosensitive resin to make a mold.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a method for manufacturing a component having fine uneven portions according to the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of a micro gear that is a component having fine uneven portions according to the present invention. The micro gear 1 is formed by die-molding a powder of a metallic glass alloy. This minute gear has a tooth portion 2 having fine irregularities on the outer periphery. FIG. 2 is a view showing a molding apparatus for manufacturing a micro gear. As shown in FIG. 2, the molding apparatus includes a cylindrical molding die 3 and an upper punch 5, a lower punch 6, and a lower punch for pressing the raw material powder 4 inserted into the molding die 3. Lower ram 8 that supports 6, upper ram 7 that presses upper punch 5 downward, and die and punch are heated to a processing temperature equal to or higher than the glass transition point of the raw powder to heat the powder to the same temperature by heat conduction It is comprised mainly by the heater 10 for performing, and the thermocouple 9 which measures processing temperature.

  FIG. 3 is a perspective view of a molding die. As shown in FIG. 3, fine irregularities 10 are formed according to the shape of the target molded product. In such a molding apparatus, the shape of the cavity formed by the upper and lower punches 5 and 6 and the molding die 3 substantially matches the shape of the target molded product.

Hereinafter, the present invention will be described specifically by way of examples.
(Example 1)
Ni, Nb, Ti, Zr are weighed so that the atomic weight ratio is 60: 15: 20: 5, and these raw materials are melted in a high-frequency induction melting furnace in a reduced pressure Ar atmosphere and kept at 1600 ° C. Droplets are formed by spraying molten metal into a granular form by the pulse injection method, and then solidifying into spheres by free-falling in an inert atmosphere to make it the same volume as the target microgear. A raw material powder with a diameter of 300 μm and a uniform particle diameter was prepared. On the other hand, in order to fabricate a micro gear having a diameter of 300 μm, a tooth width of 50 μm, and a height of 70 μm, which is the same as the volume of the powder-grain, a die having a micro gear matrix made of amorphous carbon is fabricated. After inserting the metal glass powder-grains, the die set was heated to 590 ° C., which is higher than the glass transition point, and pressed while maintaining the temperature to obtain a final product. This final product was of the desired size and could be produced without subsequent finishing of the cut-out end and cutting of unnecessary parts.

(Example 2)
Similarly to the above composition, Ni, Nb, Fe, Si, and B, which are Ni-based metallic glasses, are weighed so that the atomic weight ratio is 43.2: 4: 28.8: 4.8: 19.4, and the pressure is reduced. In an Ar atmosphere, these raw materials were melted in a high-frequency induction melting furnace, and after forming molten droplets of molten metal glass in a state maintained at 1400 ° C. by a pulse injection method to form droplets, A raw material powder having a uniform particle diameter of 300 μm in diameter and having the same volume as the volume of the target microgear was produced by free-falling in an inert atmosphere and solidifying into a spherical shape. On the other hand, after inserting the metallic glass powder-grain into the above-mentioned die having the same volume as the powder-grain, the die set is heated to 520 ° C. which is equal to or higher than the glass transition point and pressed while maintaining the temperature. By getting the final product. This final product was of the desired size and could be produced without subsequent finishing of the cut-out end and cutting of unnecessary parts.

(Example 3)
Similar to the above composition, Fe-based metallic glass Fe, Ga, P, C, B, and Si are weighed so that the atomic weight ratio is 73: 4: 11: 5: 4: 3, and in a reduced pressure Ar atmosphere. Then, these raw materials are melted in a high-frequency induction melting furnace, and molten metal glass in a state maintained at 1300 ° C. is formed into droplets by ejecting the molten metal into particles by a pulse injection method. The raw material powder having a uniform particle diameter of 300 μm in diameter having the same volume as that of the target microgear was produced by free-falling at a solid state. On the other hand, after inserting the metallic glass powder-grain into the above-mentioned die having the same volume as the powder-grain, the die set is heated to 490 ° C. which is equal to or higher than the glass transition point and pressed while maintaining the temperature. By getting the final product. This final product was of the desired size and could be produced without subsequent finishing of the cut-out end and cutting of unnecessary parts.

Example 4
Similar to the above composition, Fe-based metallic glass Fe, Co, Si, B, and Nb are weighed so as to have an atomic weight ratio of 57.6: 14.4: 4: 20: 4, and in a reduced pressure Ar atmosphere. Then, these raw materials are melted in a high-frequency induction melting furnace, and molten metal glass in a state maintained at 1400 ° C. is formed into droplets by ejecting the molten metal into particles by a pulse injection method. The raw material powder having a uniform particle diameter of 300 μm in diameter having the same volume as that of the target microgear was produced by free-falling at a solid state. On the other hand, after inserting the metallic glass powder-grain into the above-mentioned die having the same volume as the powder-grain, the die set is heated to 570 ° C. which is equal to or higher than the glass transition point and pressed while maintaining the temperature. By getting the final product. This final product was of the desired size and could be produced without subsequent finishing of the cut-out end and cutting of unnecessary parts.

(Example 5)
Similar to the above composition, Ni-based metallic glass Ni, Nb, Ti, Zr, Co, and Cu are weighed so as to have an atomic weight ratio of 53: 20: 10: 8: 6: 3. Then, these raw materials are melted in a high-frequency induction melting furnace, and molten metal glass in a state maintained at 1400 ° C. is formed into droplets by ejecting the molten metal into particles by a pulse injection method. The raw material powder having a uniform particle diameter of 300 μm in diameter having the same volume as that of the target microgear was produced by free-falling at a solid state. On the other hand, after inserting the metallic glass powder-grains into the same die as the volume of the powder-grains, the die set is heated to 595 ° C., which is higher than the glass transition point, and pressed while maintaining the temperature. By getting the final product. This final product was of the desired size and could be produced without subsequent finishing of the cut-out end and cutting of unnecessary parts.

(Example 6)
As with the above composition, Zr, Cu, Al, and Ni, which are Zr-based metallic glasses, are weighed so as to have an atomic weight ratio of 55: 30: 10: 5, and these raw materials are subjected to high-frequency induction melting in a reduced pressure Ar atmosphere. A molten metal glass melted in a furnace and maintained at 1200 ° C. is formed into droplets by ejecting the molten metal into particles by a pulse injection method, and then dropped into a spherical shape by free-falling in an inert atmosphere. A raw material powder having a uniform particle diameter of 300 μm in diameter and having the same volume as that of the target micro gear was produced by solidification. On the other hand, after inserting the metallic glass powder-grains into the same die as the volume of the powder-grains, the die set is heated to 450 ° C., which is equal to or higher than the glass transition point, and pressed while maintaining the temperature. By getting the final product. This final product was of the desired size and could be produced without subsequent finishing of the cut-out end and cutting of unnecessary parts.

(Example 7)
Similar to the above composition, Cu, Zr, Al, and Ag, which are Cu-based metallic glasses, are weighed so as to have an atomic weight ratio of 50: 40: 5: 5, and these raw materials are subjected to high-frequency induction melting in a reduced pressure Ar atmosphere. A molten metal glass melted in a furnace and maintained at 1250 ° C. is formed into droplets by ejecting the molten metal into particles by a pulse injection method, and then dropped into a spherical shape by free-falling in an inert atmosphere. A raw material powder having a uniform particle diameter of 300 μm in diameter and having the same volume as that of the target micro gear was produced by solidification. On the other hand, after inserting the metallic glass powder-grain into the above-mentioned die having the same volume as the powder-grain, the die set is heated to 480 ° C. which is equal to or higher than the glass transition point and pressed while maintaining the temperature. By getting the final product. This final product was of the desired size and could be produced without subsequent finishing of the cut-out end and cutting of unnecessary parts.

  As described above, a precision mold that can be used repeatedly by FIB, laser processing, electroforming, etc. is manufactured, and the metal glass powder of the same volume as the processed part is filled in the mold as the material, and the glass transition temperature As described above, press mold processing is performed at a temperature below the crystallization start point, so that metallic glass can be plastic flow filled into fine irregularities, and since the total volume is controlled, there is no generation of unnecessary parts and the volume-controlled powder. By using the raw materials, it is possible to combine component powders having functions according to the parts, and there is an extremely excellent effect that can realize an inexpensive mass production process by repeated use by using a mold.

It is a perspective view of a micro gear which is a component having a fine uneven portion of the present invention. It is a figure which shows the shaping | molding apparatus for manufacturing a micro gear. It is a perspective view of the die for forming.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Minute gear 2 Tooth part 3 Die | molding die 4 Raw material powder 5 Upper punch 6 Lower punch 7 Upper ram 8 Lower ram 9 Thermocouple 10 Heating heater


Patent Applicant Sanyo Special Steel Co., Ltd.
Attorney Atsushi Shiina

Claims (2)

In order to obtain a precision part shape, a metal glass alloy powder is inserted into a precision machined die, and the metal glass alloy powder is pressed with a punch while being kept at a glass transition temperature or more and a crystallization temperature or less to obtain a precision part. A method for producing a precision part, characterized in that, in the step, the powder is measured and inserted so that the volume of the metal glass alloy powder inserted into the die is the same as the volume of the precision part after pressure forming. 2. The method according to claim 1, wherein two or more kinds of metal glass alloy powders having different compositions in which the total volume of the metal glass alloy powders of each composition is the same as the volume of the precision part after pressure forming are combined in the die. A method of manufacturing a precision part, which is characterized by being inserted into a device.

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