JP2003166076A - Method and apparatus for forming composite structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To stably keep concentration of fine particles in an aerosol constant for a long time, in an aerosol generator employed for a device for forming a composite structure. <P>SOLUTION: This manufacturing method includes adjusting a quantity of curling up fine-particles in a vessel, by effectively supplying the fine particle powders to a gas introduction part, by horizontally shaking the vessel for accommodating the fine particle powders, or introducing the gas while swirling and vibrating it; and further stabilizing the quantity by adjusting the shaking speed. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention produces a composite structure composed of a base material and a structure by spraying an aerosol containing fine particles onto a base material and forming a structure composed of the fine particle material on the base material. The present invention relates to a composite structure manufacturing method and a composite structure manufacturing apparatus.

[0002]

2. Description of the Related Art As a method for forming a film made of a particulate material on a substrate, a gas deposition method (Kei Shuichiro: Metal
(1989 January issue) is known. In this method, ultrafine particles of metal or ceramics are aerosolized by gas agitation, accelerated through a fine nozzle to form a powder compact layer of ultrafine particles on the surface of the base material, which is heated and baked to form a film. Form. For example, JP-A-11-299
In Japanese Patent No. 879, an aerosol supply part composed of a carrier gas and fine particles of a biocompatible material, a nozzle, a heating device, a temperature measuring device, and a base material are provided, and the carrier gas is introduced into the aerosol supply part. To generate an aerosol and spray it from a nozzle onto a base material to form a particulate deposit on the base material and heat the base material and the deposit to sinter to produce an artificial biocompatible structure / functional component. Proposed.

As a technique improved from the above gas deposition method, there is a method of forming a film or structure of a brittle material called a particle beam deposition method or an aerosol deposition method. This is because an aerosol containing fine particles of a brittle material is jetted from a nozzle toward a substrate at high speed, the fine particles collide with the substrate, and the mechanical impact force is used to bring a polycrystalline structure of the brittle material onto the substrate. This is a method of forming directly, and is disclosed in JP-A-11-21677 and JP-A 2000-
The one disclosed in JP-A-212766 is known.

The technique disclosed in Japanese Unexamined Patent Publication (Kokai) No. 11-21677 discloses that when the above-mentioned aerosol containing ultrafine particles is conveyed or when ceramics or the like is heated and evaporated,
In order to prevent the ultrafine particles from aggregating into large particles, a classifying device is arranged in an intermediate path.

In Japanese Patent Laid-Open No. 2000-122766, ultrafine particles such as ceramics having a particle size in the range of 10 nm to 5 μm are dispersed in a gas to form an aerosol, and then a high speed ultrafine particle flow is directed toward a substrate from a nozzle. Spray to form deposits. At this time, the ultrafine particles and the substrate are irradiated with ions, atoms, molecular beams, high-energy atoms such as low-temperature plasma, and the like to make a structure strong so that the structure is strengthened. Further, according to FIG. 5 of the publication, the aerosol chamber for generating an aerosol employs a device for agitating and mixing the ultrafine particles by introducing gas and vertically vibrating in the direction of the gravity vector to form an aerosol.

[0006]

The aerosol generating means shown in the prior art is a method of introducing a gas by burying a gas introducing pipe in powder in a stationary aerosol supplying section, or moving an aerosol chamber up and down. However, if the gas is continuously introduced while the aerosol supply unit is stationary, the powder near the opening of the gas introduction pipe will be immediately blown off, and the amount of aerosol will be stably supplied for a long period of time. Difficult to do. Although this adverse effect is eliminated to some extent by moving the aerosol chamber up and down and stirring, up and down movement causes packing (compressing action) of the powder, and depending on the powder, sticking occurs with vibration, which also causes aerosol generation. It has a negative effect on the long-term stability of the quantity. These aerosol generation methods used in a method of colliding fine particles with a base material to form a structure thereof may require continuous operation for several tens of minutes to several hours to form a structure. It can be said that long-term stable supply is essential for industrial use.

[0007]

First, an explanation will be given of an aerosol deposition method for forming a brittle material structure on a substrate, which is a method for producing a composite structure, which is a place where the present invention is carried out. When a mechanical impact force is applied to a brittle material (ceramics) having no malleability, a crystal lattice shifts or is crushed along the cleavage plane such as the interface between crystallites. When these phenomena occur, a new surface in which the atoms originally existing inside and bonded to another atom are exposed is formed on the slip surface and the fracture surface. A part of the atomic layer on the new surface is exposed from an originally stable atomic bond state to an unstable surface state by an external force, and has a high surface energy. This active surface is joined to the surface of the adjacent brittle material, the new surface of the adjacent brittle material or the surface of the base material, and shifts to a stable state. The continuous application of a mechanical impact force from the outside continuously causes this phenomenon, and the deformation and crushing of the fine particles repeatedly cause the progress of bonding and densification to form a brittle material structure.

The aerosol deposition method is a method in which the brittle material is caused to collide with the base material by the carrier gas with the mechanical impact. This method is a method that has been developed from the gas deposition method, and conveys an aerosol in which fine particles of a brittle material are dispersed in a gas, jets them at a high speed onto the surface of the base material to collide, and crushes and deforms the fine particles. By forming an anchor layer at the interface with the base material and bonding it together, and by bonding the crushed fragment particles together, a brittle material structure with good adhesion to the base material and high strength can be directly applied to the base material. Can be formed.

The present invention has found a suitable constitution as an aerosol generator used in the above-mentioned aerosol deposition method, but it can also be used in the gas deposition method, and therefore, a brittle material fine particle as fine particle powder. Besides, metal fine particles and the like can also be used.

In the present invention, an aerosol is generated in a method for producing a composite structure in which an aerosol in which fine particles are dispersed in a gas is collided with a base material at high speed to produce a composite structure composed of the base material and the fine particle material. In order to stir the microparticles by accommodating the microparticles in a container and mechanically vibrating the microparticles in a direction approximately at right angles to the direction of the gravity vector, a gas is blown to the microparticles so that the microparticles rise in the air stream. In the composite structure manufacturing apparatus as one embodiment thereof, an aerosol generator for generating an aerosol and a nozzle for causing the aerosol generated by the aerosol generator to collide with a base material at a high speed are provided. Is a container for containing fine particles, an inlet connected to the container for introducing gas, and an air generated in the container connected to the container. Has a guiding outlet for deriving a sol nozzle side, and a vibration means for imparting a mechanical vibration action to the container,
It is characterized in that the vibrating means is used to vibrate in a direction substantially perpendicular to the direction of the gravity vector to stir the fine particles, and at the same time a gas is blown from the inlet to the fine particles to generate an aerosol.

Here, the fine particles include brittle materials such as ceramics and semiconductors, metallic materials and mixtures thereof, or fine ceramic particles coated with ceramics, metal or resin.

A cylindrical container having a capacity of about several hundred mL to about 1 L is used as the container, and several tens to several hundred mL of the fine particle powder is stored in the container, and the inlet is directly above the surface of the fine particle powder. The gas is blown by locating at the position or burying the inlet inside the powder. At this time, it vibrates in a direction approximately perpendicular to the direction of the gravity vector, but the approximately right angle is substantially an inclination within 10 ° from the perpendicular direction. A so-called horizontal reciprocating vibration can be considered as the vibration action. Since there is no movement in the direction of gravity as compared with vertical vibration, packing of powder is less likely to occur, and therefore, long-term stability of aerosol generation is maintained as compared with vertical vibration. The amount of aerosol generated can be controlled by adjusting the lateral vibration speed.

The size of the particles is 1 m together with the particles in the container.
It is even better to accommodate crushed fine particles of m or more. For example, a ceramic ball or the like corresponds to this. When vibration is continuously applied to the fine particle powder, the fine particles start to agglomerate due to static electricity generated by the vibration, and sometimes a large number of agglomerates with a diameter of several mm are formed. In such a state, generation of aerosol becomes difficult to occur, that is, long-term stability is impaired. Therefore, by accommodating the crushed particles of fine particles together with the powder and stirring them simultaneously, it becomes possible to loosen the agglomeration of the fine particles, which is preferable. This cohesive disintegration is particularly effective when the gas is blown to the fine particle powder with the introduction port positioned directly above the powder surface. In addition to the crushing action, mixing of powder using a rotary blade that does not depend on the vibration action can also produce a certain effect. However, in the case of mixing, if the degree is too high, it causes the powder to adhere to the wall surface of the container, which causes deterioration in long-term stability.

As another aspect, the mechanical vibration action is a vortex vibration having an axis in the gravity vector direction. Explaining the vortex vibration in the case of using a cylinder as a container, it means that the container itself does not rotate, but the center axis of the cylinder makes a scroll motion by tracing along a circle with a radius almost perpendicular to it. And
At this time, the case where the center axis of the container moves so as to draw the shape of the side surface of the cone is also included. In this case as well, the movement of the central axis itself is a rotational movement that traces a plane approximately perpendicular to the direction of the gravity vector. When such a movement is performed, the fine particle powder contained in the container independently makes a circular rotation movement about the central axis of the container in spite of the fact that the container does not rotate. . Therefore, by positioning the inlet here and blowing gas, or by burying the inlet here and blowing out the gas, new powder is constantly supplied near the opening of the inlet by a rotary motion, It becomes possible to stably generate an aerosol.

Further, the outlet of the aerosol is located at the upper part of the powder contained in the container, and the fine particle powder blown up reaches the opening by the air flow and is discharged. Another aspect of the present invention is characterized in that a shielding means for preventing the aggregated particles in the aerosol generated between the opening of the outlet and the contained fine particles from being discharged is installed. In the aerosol deposition method, it is desirable that the fine particles in the aerosol have a large amount of primary particles, but fine particle powder having a particle size of 0.1 to 5 μm tends to agglomerate. When aerosol is generated by spraying, it is feared that it contains agglomerated particles. If large particles among these agglomerates are sprayed onto the base material during the formation of the structure, they will adhere to the formation surface and hinder the subsequent formation of the structure, or have the adverse effect of scraping off the completed structure. To wake up. Therefore, excluding these agglomerates is a factor for healthy structure formation, but the above-mentioned shielding coma prevents the agglomerates in the aerosol from reaching the outlet, so that fine particles relatively close to the primary particles are Plays a role of selectively deriving. This is because primary particles and relatively small agglomerates with some agglomeration tend to move along the streamline of the air stream, while coarse agglomerates have a relatively large inertia, so gas was blown. This is because, after that, it moves relatively straight and moves toward the outlet or toward the upper part of the container. Therefore, the shielding means is arranged so that the opening of the outlet is hidden when seen from the surface of the fine particle powder contained therein. Is desirable. Since it is difficult to specify that the particle size of agglomerated particles, which is the boundary between structure formation and its inhibition, differs depending on the powder type, it is practically necessary to set various setting conditions such as the size and position of the shielding means and the gas flow rate. It is advisable to appropriately select and select a structure that does not cause any inhibition such as etching and powder compact formation.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings. First, a structure manufacturing apparatus in the aerosol deposition method using the aerosol generator of the present invention will be described.

FIG. 1 shows an apparatus 1 for manufacturing a composite structure, in which a gas transfer pipe 102 is provided before a nitrogen gas cylinder 101.
The aerosol generator 103 is installed through the structure forming chamber 10 via the aerosol transfer pipe 104 on the downstream side thereof.
A nozzle 106 having an ejection opening of 10 mm × 0.4 mm is installed in the nozzle 5. Aerosol generator 103
Brittle material fine particles such as aluminum oxide fine particle powder are filled in the inside. A base material 107 is arranged at the tip of the opening of the nozzle 106, and the base material 107 is fixed to the XY stage 108. The structure forming chamber 105 is a vacuum pump 10.
9 is connected.

The operation of the composite structure manufacturing apparatus 1 based on the aerosol deposition method will be described below. The nitrogen gas cylinder 101 is opened, the gas is sent into the aerosol generator 103, and at the same time, the aerosol generator 103 is operated to generate the aerosol in which the brittle material particles and the nitrogen gas are mixed in an appropriate ratio. Further, the vacuum pump 109 is operated to generate a differential pressure between the aerosol generator 103 and the structure forming chamber 105. This aerosol is transferred to the aerosol carrier pipe 10.
4 to accelerate, and jet from the nozzle 106 toward the substrate 107. The base material 107 is swung by the XY stage 108, and a film-like brittle material structure is formed on the base material 107 by collision of fine particles while changing the aerosol collision position.

Next, an embodiment of the aerosol generator adopted in the composite structure manufacturing apparatus represented by the above-mentioned structure will be described. FIG. 2 shows an aerosol generator 2 as one embodiment of the present invention, in which a cylindrical container 201 of about 500 mL is provided with an inlet 202 for introducing gas and an outlet 203 for leading out the generated aerosol. Then, the fine particle powder 204 is filled therein, and a plurality of alumina spheres 205 having a diameter of 10 mm are mixed therein. This fine particle powder 2
04 may be ceramic powder such as aluminum oxide described above, or may be powder of a metal material. The opening of the introduction port 202 has a diameter of 2 mm, and the fine particle powder 20 is provided at a position of several mm near the surface of the fine particle powder 204.
4 is open, and the outlet port 203 has a diameter of 4
mm, and an opening is opened at a position approximately 8 cm above the fine particle powder 204. This container 201 is installed in a shaker 206.

The operation and effect of the aerosol generator 2 having the above structure will be described. A gas such as nitrogen is introduced from the introduction port 202 at a rate of several to several tens of liters per minute, and at the same time, the shaker 20
Drive 6 The shaker 206 is operated at an amplitude of about 2 cm and a shaking speed of 30 to 300 reciprocations / minute in the horizontal direction as shown by the arrow in FIG. Due to this action, the gas is fine particle powder 2
04 is rolled up in a container to generate an aerosol. The concentration of fine particles in the aerosol can be adjusted by changing the shaking speed. When the aerosol is continuously generated in this manner, the fine particle powder 204 is gradually aggregated due to the movement. The alumina spherulites 205 mixed therein are subjected to a stirring action by shaking to break up the aggregated particles. Therefore, it is possible to suppress a decrease in the concentration of the aerosol due to aggregation. The generated aerosol flows along the air flow toward the outlet 203, and is discharged to the outside of the aerosol generator 2 from here. The aerosol thus produced has the composite structure production apparatus 1 shown in FIG.
Of the aluminum oxide and forms a structure of aluminum oxide, for example.

FIG. 3 shows an aerosol generator 3 as another embodiment of the present invention. A plurality of inlets 302 are provided on the side surface near the bottom of a cylindrical container 301 of about 800 mL.
Is installed, and the outlet port 303 is installed at a position on the central axis above the container 301. Each of these openings has a diameter of 2
mm and diameter 4 mm. Fine particle powder 304
Is housed. Further, immediately below the opening of the outlet port 303, an agglomerated particle blocking piece 305 having a diameter of 2 cm, which is an agglomerated particle blocking means, is supported from the bottom of the container 301, and is installed with the conical portion facing upward with the opening. The container 301 is a rotary motor 306.
Eccentric shaft 3 with a radius of 2.5 mm installed at the end of
The upper lid is semi-fixed to the column 308 and is pressed against the eccentric shaft 307 by the compression spring 309.

The operation and effect of the aerosol generator 3 having the above structure will be described. A gas such as nitrogen is introduced from the inlet 302, the rotary motor 307 rotates as indicated by an arrow in FIG. 3, and the eccentric shaft 307 vortexes the bottom surface of the container 301 to draw a circle having a diameter of 5 mm. Container 3
Since 01 itself is semi-fixed to the column 308, it does not rotate. However, the unrestricted fine particle powder 304 receives this vortex vibration and freely rotates in the rotation direction of the rotation motor 307. Due to this action, the inlet 302
The fine particles are successively sent in the vicinity of the opening of and are blown up, and the stirring action stably generates the aerosol. Further, a part of the fine particle powder 304 forms agglomerated particles, which may cause agglomerated particles to be included in the aerosol immediately after being generated in the container 301. Since these agglomerated particles have a relatively large weight, after being blown up due to their inertia, they move linearly in the container 301 as compared with the primary particles that are easy to ride in the air flow. On the other hand, the agglomerated particle shielding piece 305 has a function of forming a bent airflow near the opening of the outlet 303, so that the primary particles that easily ride the airflow avoid the agglomerated particle shielding piece 305 and the aerosol generator 3 from the outlet 303. On the other hand, the aggregated particles do not reach the opening by colliding with the aggregated particle shielding pieces 305, while being discharged to the outside.
Therefore, it becomes possible to produce an aerosol in which agglomerated particles are less mixed. Since the concentration of fine particles in the aerosol changes sensitively in response to the number of rotations of the rotary motor 306, it is possible to control this to generate an aerosol of a desired concentration in a stable manner for a long period of time.

Further, the direction of the opening of the introduction port 302 is opposite to that of the rotation motor 306, that is, the fine particle powder 304.
It is preferable to direct the particles toward the downstream side in the rotation direction since it is possible to eliminate the adverse effect that the fine particles enter from the opening and block the inlet 302. Further, the position of the opening may be placed near the side surface of the container 301. Because fine particle powder 304
Since the centrifugal force acts due to the rotational movement of the container, when the aerosol generator is operated for a long time, packing sometimes occurs at the side surface position of the container 301, and by blowing gas from the vicinity of the side surface, the centrifugal force is opposite to the centrifugal force. This is because force can be applied or the powder can be loosened by gas before packing occurs.

FIG. 4 shows an aerosol generator 4 according to another embodiment of the present invention, in which an inlet port 402 is installed on a side surface near a bottom of a cylindrical container 401 of about 800 mL, and The outlet 40 is located above the central axis.
3 is installed. These openings are 2 mm and 4 m, respectively
m. A mesh 405 having pores that prevent the fine particle powder 404 from leaking is installed above the outlet port 403, and the fine particle powder 404 is filled on the mesh 405. Outlet port 4
Immediately below the opening of 03, the agglomerate particle blocking piece 40 with a diameter of 2 cm
6 is supported from the bottom of the container 401, and is installed with the conical portion facing upward with an opening. The container 401 is a rotary motor 40.
7 is mounted on an eccentric shaft 408 having an eccentricity with a radius of 2.5 mm, and the upper lid part is semi-fixed to a column 409 and pressed against the eccentric shaft 408 by a compression spring 410.

The operation of the aerosol generator 4 having the above-mentioned structure is similar to that of the aerosol generator 3 described above, and the gas introduced from the introduction port 402 is dispersed in a relatively gentle manner through the mesh and is stored in the container. There is a difference in forming an airflow toward the upper part of 301. Therefore, the primary particles are gently rolled up from the entire surface of the fine particle powder 404 to generate an aerosol, which is preferable. Figure 4
Although the aggregated particle shielding piece 406 is installed therein, it is practically practical without it because the aggregated particles are not adversely mixed with the aerosol due to the above-described generation mechanism.

[0026]

As described above, according to the present invention,
In a composite structure manufacturing method and a composite structure manufacturing apparatus in which an aerosol in which particles are dispersed in a gas is collided with a base material at high speed to form a structure of particles, vibration of an aerosol generator is applied to a gravity vector direction. By blowing the gas to the fine particles while giving it in a direction approximately at a right angle, the concentration of the fine particles in the aerosol can be relatively stabilized and generated for a long time. In addition, it became easy to eliminate the problem that coarse agglomerated particles are contained in the aerosol.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a structure manufacturing apparatus used in an aerosol deposition method.

FIG. 2 is a schematic diagram showing an aerosol generator 2 according to one embodiment of the present invention.

FIG. 3 is a schematic diagram showing an aerosol generator 3 according to one embodiment of the present invention.

FIG. 4 is a schematic diagram showing an aerosol generator 4 according to one embodiment of the present invention.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masakatsu Kiyohara             2-1-1 Nakajima, Kokurakita-ku, Kitakyushu City, Fukuoka Prefecture             No. Totoki Equipment Co., Ltd. (72) Inventor Katsuhiko Mori             2-1-1 Nakajima, Kokurakita-ku, Kitakyushu City, Fukuoka Prefecture             No. Totoki Equipment Co., Ltd. (72) Inventor Atsushi Yoshida             2-1-1 Nakajima, Kokurakita-ku, Kitakyushu City, Fukuoka Prefecture             No. Totoki Equipment Co., Ltd. (72) Inventor Kaori Yamaguchi             2-1-1 Nakajima, Kokurakita-ku, Kitakyushu City, Fukuoka Prefecture             No. Totoki Equipment Co., Ltd. (72) Inventor Tomokazu Ito             2-1-1 Nakajima, Kokurakita-ku, Kitakyushu City, Fukuoka Prefecture             No. Totoki Equipment Co., Ltd. (72) Inventor Jun Akito             1-1-1 Higashi 1-1-1 Tsukuba City, Ibaraki Prefecture             National Institute of Advanced Industrial Science and Technology Tsukuba Center             Within F-term (reference) 4F033 QA01 QB02Y QB05 QB13Y                       QB19 QB20 QC07 QD02 QD05                       QD06 QD11 QE05 QF01X                       QF02Y QF15X QF15Y QH05                       QH08 QH10 QH11                 4G075 AA24 AA27 AA30 BB04 BB05                       BB08 DA02 DA18 EB01 EC01                       ED15                 4K044 BA01 BA13 BA21 BB11 CA23                       CA53

Claims (7)

[Claims] 1. A method for producing a composite structure in which an aerosol in which fine particles are dispersed in a gas is collided with a base material at a high speed to produce a composite structure composed of the base material and the fine particle material.
In order to generate the aerosol, the fine particles are stored in a container, a mechanical vibration action is applied to the fine particles in a direction approximately perpendicular to the direction of the gravity vector to stir the fine particles, and the gas is applied to the fine particles. A method for producing a composite structure, which comprises spraying the fine particles so as to rise in an air stream. 2. The method for producing a composite structure according to claim 1, wherein a crushed fine particle fragment having a size of 1 mm or more is accommodated in the container together with the fine particle. 3. The mechanical vibration action is a vortex vibration having an axis in the gravity vector direction as an axis.
Alternatively, the method for producing a composite structure according to item 2. 4. An aerosol generator for generating an aerosol in which fine particles are dispersed in a gas, and a nozzle for colliding the aerosol generated by the aerosol generator with a base material at a high speed, and the base material. In a composite structure manufacturing apparatus for manufacturing a composite structure made of a particulate material, the aerosol generator is a container for containing the particles, an inlet connected to the container for introducing gas, and connected to the container. It has a discharge port for discharging the aerosol generated in the container to the nozzle side, and a vibrating means for giving a mechanical vibrating action to the container, and is approximately perpendicular to the gravity vector direction using the vibrating means. The composite structure is characterized in that the fine particles are agitated by vibrating in a direction to stir the fine particles and a gas is blown from the introduction port to the fine particles to generate an aerosol. Structure making device. 5. The apparatus for producing a composite structure according to claim 4, wherein the aerosol generator accommodates, in the container, the fine particles together with a crushed fine particle fragment having a size of 1 mm or more. 6. The mechanical vibration action is a vortex vibration having an axis in the gravity vector direction as an axis.
Or the composite structure manufacturing apparatus according to 5. 7. In the aerosol generator, a shielding means is provided vertically below the opening of the outlet to prevent aggregated particles in the generated aerosol from being led out from the outlet. Item 7. The composite structure manufacturing apparatus according to items 4 to 6.