JP5099575B2 - Method for manufacturing brittle material structure - Google Patents

Description

The present invention relates to a manufacturing method of the brittle material structure, and more particularly, relates to a manufacturing method of the brittle material structure aerosols consisting of powder and gas is injected into the surface of the substrate to form a film-like body.

As a method for forming a film-like body of a brittle material on the substrate surface, there is an “aerosol deposition method” (hereinafter referred to as AD method) (for example, Patent Document 1 and Patent Document 2). This is because “aerosol” in which fine particles containing brittle materials are dispersed in a gas is continuously sprayed from the nozzle toward the base material, causing the fine particles to collide with a base material such as metal, glass, ceramics or plastic. This is a method in which a brittle material fine particle is deformed or crushed by the impact of a collision, and these are joined to form a film-like body made of a constituent material of the fine particle directly on a substrate. According to this method, a film-like body can be formed at room temperature without requiring any heating means, and a film-like body having mechanical strength equal to or higher than that of the fired body can be obtained. In addition, the density, mechanical strength, electrical characteristics, and the like of the film-like body can be varied in various ways by controlling the conditions under which the fine particles collide, the shape and composition of the fine particles, and the like.
Japanese Patent No. 3348154 JP 2000-212766 A

  In many cases, the AD method is carried out by continuously injecting aerosol onto a substrate in a vacuum or a reduced-pressure atmosphere. On the other hand, it is convenient if a film-like body made of a brittle material can be deposited under atmospheric pressure or a high pressure close thereto. As a result of carrying out an independent study from this point of view, the present inventor has gained new knowledge about the deposition mechanism of the AD method.

The present invention has been made based on such new knowledge, and is a brittle material structure capable of depositing a film-like body made of a brittle material not only in a vacuum or reduced pressure environment but also at atmospheric pressure or a pressure equivalent thereto. A manufacturing method is provided.

According to one aspect of the present invention, while relatively displacing the nozzle and the substrate, fine particles as aerosol dispersed in gas collisions on the substrate, the base of the aerosol from the nozzle A method of manufacturing a brittle material structure , which is injected toward a material to form a composite structure of a brittle material structure composed of the fine particle constituent material and the base material, and the aerosol collides with the base material Is performed in an atmosphere of substantially atmospheric pressure, and a first step of injecting the aerosol toward the base material for a first predetermined time; and a second step of injecting the aerosol onto the base material. A second step of stopping for a predetermined time, and alternately repeating the first step and the second step to cause the aerosol to intermittently collide with the substrate. , the first predetermined time being less 1 second Method for producing a brittle material structure, wherein is provided.
According to the said structure, the manufacturing method of the brittle material structure which can deposit the film-form body which consists of a brittle material without requiring a pressure-reduced environment can be provided.

  Here, “intermittent” in the specification of the present application refers to a state where the aerosol collides discontinuously with respect to time in a specific part on the substrate. Therefore, the case where the aerosol is continuously ejected from the nozzle and the case where the aerosol is intermittently ejected are included.

  For example, the intermittent collision of the aerosol with the base material may be an intermittent collision with a specific part on the base material based on the switching of the position of the injection port of the nozzle.

  Alternatively, the intermittent collision of the aerosol on the substrate may be based on intermittent injection of the aerosol onto the substrate.

  Here, the interval of the intermittent collision of the aerosol with the base material is close to the surface of the base material based on the collision of the aerosol with the base material after stopping the collision of the aerosol with the base material. If the gas stagnation region formed is longer than the time until the gas stagnation region substantially disappears, the action of the pressure barrier due to the gas stagnation region is avoided, and the fine particles collide with the substrate at high speed. Brittle material structures can be formed at high deposition rates.

  Moreover, if the interval between the collision of the aerosol and the base material is 0.1 seconds or more, the gas stagnation region can be efficiently eliminated.

  Here, if the aerosol is made to collide with the base material under substantially atmospheric pressure, a facility for forming a reduced pressure environment is unnecessary, and it can be used for a wide range of applications at low cost. A method of manufacturing a brittle material structure can be provided.

  Further, if the nozzle and the base material are relatively displaced so that the brittle material structure is continuously formed on the surface of the base material, even under an atmospheric pressure or a pressure close thereto, A continuous film-like brittle material structure can be formed at a high deposition rate.

  In the specification of the present application, the term “fine particles” refers to particles having an average particle diameter of 50 micrometers or less identified by particle size distribution measurement, a scanning electron microscope, or the like in the case of dense particles.

  In the present specification, “aerosol” is obtained by dispersing the above-mentioned fine particles in a gas such as helium, nitrogen, argon, oxygen, dry air, or a mixed gas containing these, and these fine particles are used as a gas alone. A state in which the fine particles are aggregated and a state in which the aggregated particles in which these fine particles are aggregated are dispersed in the gas. The gas pressure and temperature of the aerosol are arbitrary, but the concentration of fine particles in the gas is 0.0003 mL at the time of injection from the nozzle outlet when the gas pressure is converted to 1 atm and the temperature is converted to 20 degrees Celsius. It is desirable for the formation of a film-like structure to be in the range of / L to 0.06 mL / L.

  Moreover, although the speed | rate which sprays aerosol to the film-forming board | substrate is arbitrary, it is desirable to set it as 20 m / sec or more, and it is more desirable to set it as the range of 100-450 m / sec.

  According to the present invention, a film-like body made of a brittle material can be stably produced even under atmospheric pressure or a high pressure close thereto by intermittently injecting an aerosol comprising fine particles and gas onto the substrate surface. Industrial benefits are tremendous.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
Drawing 1 is a mimetic diagram showing the manufacturing method of the brittle material structure concerning an embodiment of the invention.

In the present embodiment, the aerosol is intermittently ejected while the base material 100 on which the brittle material is deposited and the nozzle 200 that ejects the aerosol are relatively displaced.
For example, in the case of the specific example shown in FIG. 1, first, as shown in FIG. 1A, a pulsed aerosol P <b> 1 is jetted from the nozzle 200 onto the surface of the base material 100 to form a first material made of a brittle material. The deposition part D1 is formed. Next, after the aerosol injection is temporarily stopped, the substrate 100 is moved in the horizontal direction A relative to the nozzle 200. Here, the moving amount of the base material 100 can be determined as appropriate so that the deposition part is continuously formed. In addition, instead of moving the base material 100, the nozzle 200 may be moved, or both of them may be moved.
Next, as shown in FIG. 1B, a pulsed aerosol P2 is injected, and the second deposition part D2 made of a brittle material is made adjacent to the first deposition part D1 or partially overlapped. Form. The positional relationship between the first deposition part D1 and the second deposition part D2 can be adjusted by the amount of movement of the substrate 100. Since the interface between the second deposition part D2 and the first deposition part D1 formed in this way is homogeneous in quality, it can be regarded as a continuous deposition part made of a uniform brittle material. . Next, after the aerosol injection is temporarily stopped, the substrate 100 is moved in the horizontal direction A relative to the nozzle 200.

Thereafter, as shown in FIG. 1C, a pulsed aerosol P3 is sprayed to form a third deposit D3 made of a brittle material adjacent to or overlapping the second deposit D2. Also in this case, the interface structure between the third deposit D3 and the second deposit D2 is homogeneous in quality, and can be regarded as a uniform brittle material. Next, after the aerosol injection is temporarily stopped, the substrate 100 is moved in the horizontal direction A relative to the nozzle 200 so that the brittle structural material can be continuously formed.
The series of steps described above are sequentially repeated, and, as shown in FIG. 1D, the pulsed aerosol Pn is injected to change the nth deposit Dn made of a brittle material into the (n-1) th deposit Dn. -1 adjacent or overlapping. In this way, a continuous film-like body of a brittle material having a substantially uniform film thickness can be deposited on the substrate 100.

  In addition, in FIG. 1, although the specific example which sprays aerosol intermittently and moves the base material 100 according to it intermittently was represented, this invention is not limited to this, For example, the base material 100 and The aerosol may be intermittently injected while moving the nozzle 200 relatively continuously.

2 to 6 are schematic views for explaining the mechanism of the method for manufacturing the brittle material structure according to the present embodiment.
First, FIG. 2 is a schematic diagram for explaining a change in the flow of gas immediately after the start of gas injection from the nozzle to the substrate surface under atmospheric pressure.
FIG. 5A shows the moment when the gas C10 starts to be injected from the nozzle 200 onto the surface of the substrate 100. FIG. The gas C10 ejected from the nozzle 200 travels toward the surface of the substrate 100 and collides with the surface.
Then, as illustrated in FIG. 2B, the flow A of the gas C <b> 10 flowing out in the direction of spreading along the surface of the base material 100 with the collision point as the center starts to be formed. At this time, a gas stagnation region B10 is formed in the vicinity of the collision point on the surface of the base material 100 of the gas C10. This stagnation region B10 is formed so as to be surrounded by a gas flow A flowing out in a direction spreading around the collision point, and is a portion where the gas density (or pressure) is higher than the surroundings and the fluid resistance is large. is there.

  When the gas C10 continues to be ejected, as shown in FIG. 2C, a steady flow A of the gas C10 spreading around the collision point with the base material 100 is formed. Along with the formation of this steady flow, the stagnation region B10 also grows to a steady size.

  As described above, when gas injection is started from the nozzle 200 toward the surface of the base material 100, a steady flow A of gas that spreads around the point of collision with the base material 100 as time passes is obtained. A steady gas stagnation region B10 is formed inside.

Next, the movement of fine particles when aerosol is ejected will be described. When aerosol is injected, the movement varies depending on the size (or weight) of the fine particles. Hereinafter, the movement of small particles and the movement of large particles will be described.
According to the experiment by the present inventor, fine particles having a small particle size are deposited on the surface of the substrate to form a deposit, whereas fine particles having a large particle size are deposited on the surface of the substrate. It has been found that it has a function of imparting kinetic energy to fine particles having a small particle size and promoting the deposition thereof. In other words, by colliding from above the small fine particles that have reached the vicinity of the surface of the substrate, the small fine particles are given a large collision energy, thereby forming a dense deposit. On the other hand, fine particles having a large particle diameter also have an etching action due to the blast effect on the deposit.

  Here, “small particles” means particles having a particle size of less than 1 μm, and “large particles” means particles having a particle size of approximately 1 μm or more.

FIG. 3 shows a deposition behavior when an aerosol containing small fine particles is sprayed onto a substrate, and FIG. 4 is a schematic diagram showing a deposition behavior when an aerosol containing large fine particles is used. That is, these drawings are schematic diagrams for explaining the movement of the fine particles in a state where a steady flow is formed.
As shown in FIG. 3, in a state where a steady flow is formed by injecting the aerosol C10 containing the small fine particles SP10 from the nozzle 200 to the base material 100, as described above with reference to FIG. A flow A spreading around the collision point with the base material 100 is formed, and a stagnation region B10 is formed inside thereof.

In this steady state, small (or light) fine particles tend to flow out along the flow A outside the stagnation region B10, and thus do not collide with the base material 100. On the other hand, the small fine particles SP10 that have flowed into the stagnation region B10 as represented by the arrow B are greatly reduced in speed because the stagnation region B10 acts as a pressure barrier, and are unlikely to accumulate on the surface of the substrate 100. Even if these fine particles SP10 are deposited, the density of the deposit is low. That is, the small fine particles are greatly decelerated in the stagnation region B10 due to their small inertia, and do not reach the collision speed necessary for forming a dense film-like body.
FIG. 4 is a schematic diagram for explaining the movement of large fine particles in a state where a steady flow is formed.

As shown in FIG. 2A, in a state where a steady flow is formed by injecting the aerosol C10 containing the large fine particles LP10 from the nozzle 200 to the base material 100, as described above with reference to FIG. The stagnation region B10 is formed in the vicinity of the collision point with the substrate 100.
In this steady state, the large (or heavy) fine particles LP10 enter the stagnation region B10 due to the large inertia, and the speed is slightly reduced due to the influence of the pressure barrier, but the substrate 100 moves straight as it is. There is a high probability of collision with the surface. However, such a large fine particle LP10 has a large etching effect due to the blast effect, and as a result, it is difficult to grow as a deposit.

FIG. 5 is a graph illustrating the transition of the deposition rate with respect to the aerosol injection time ST under a pressure close to atmospheric pressure.
When the aerosol injection is started on the surface of the substrate under a pressure close to the atmospheric pressure, a transition region T1 in which the deposition rate DR gradually decreases as the aerosol injection time ST increases. This is because, as described above with reference to FIGS. 2 to 4, as the gas flow transitions to a steady state, a gas stagnation region is formed, and the particles contributing to the deposition decrease or collide with the substrate. This is because it becomes difficult.

  When the stagnation region B10 (FIG. 2) and the flow A flowing out toward the periphery of the stagnation region B10 are constantly formed, a steady region T2 is obtained. In the steady region T2, the deposition rate DR decreases to a steady level and stabilizes. As will be described in detail later with reference to examples, the deposition rate DR in the steady region T2 is very small and may be close to zero. That is, under a pressure close to atmospheric pressure, it is difficult to form a thick film state even if aerosol is continuously ejected.

On the other hand, according to the present embodiment, the transition region T1 in which a high deposition rate can be obtained can be repeated by intermittently injecting aerosol. As a result, a thick film of brittle material can be formed at a high deposition rate even under atmospheric pressure or a high pressure close thereto.
6 and 7 are schematic diagrams continuously showing the behavior of deposition when aerosol is intermittently ejected from the nozzle to the substrate surface in the present embodiment.

  First, as shown in FIG. 6A, the injection of the aerosol P10 from the nozzle 200 to the base material 100 is started. When the aerosol P10 collides with the surface of the substrate 100, as shown in FIG. 6B, the formation of the deposit D10 is started, and at the same time, a gas stagnation region starts to be formed in the vicinity of the collision point. The aerosol P10 flows out in the direction A spreading along the substrate surface 100.

  In the transition state of the spray flow of the aerosol P10, as shown in FIG. 6C, the deposit D10 grows and the stagnation region B10 also expands. As shown in FIG. 6D, when the spray flow of the aerosol P10 reaches a steady state, the growth of the deposit D10 is stopped due to the presence of the stagnation region B10, or the deposition rate is significantly reduced.

  Next, in order to remove the gas stagnation region B10, the aerosol injection is temporarily stopped as shown in FIG. And the base material 100 and the nozzle 200 are relatively moved to the horizontal direction A10 so that a deposit may form continuously. In addition, you may move the base material 100 continuously instead of moving intermittently according to the injection of aerosol.

  Then, as shown in FIG. 7A, the injection of the pulsed aerosol P20 is started so as to be adjacent to or overlap the deposit D10 deposited in the step of FIG. 6E.

  Then, as shown in FIG. 7B, the formation of the deposit D20 is started in close contact with the deposit D10, and at the same time, a gas stagnation region B20 starts to be formed in the vicinity of the collision point, and the aerosol P20 is formed on the base material. It begins to flow in the direction A extending along the surface 100 and the surface of the deposit D10. In the transition state of the spray flow of the aerosol P20, as shown in FIG. 7C, the deposit D20 continues to grow in close contact with the deposit D10, and the gas stagnation region B20 near the collision point also expands. .

Thereafter, as shown in FIG. 7D, when the spray flow of the aerosol P20 reaches a steady state, the growth of the deposit D20 and the expansion of the stagnation region B20 almost stop. Therefore, as shown in FIG. 7E, the aerosol injection is temporarily stopped, and the gas stagnation region B20 is removed. Thereafter, the base material 100 and the nozzle 200 are relatively moved in the horizontal direction A10 so as to be continuously formed with the deposit D20.
As described above, by repeating the series of steps shown in FIGS. 6 and 7, a brittle material structure can be manufactured by the AD method at a high deposition rate even under a high pressure such as atmospheric pressure. .

  In the present embodiment, the deposit SP10 is formed by the small fine particles SP10 (FIG. 3) colliding with the surface of the substrate 100 at a high speed. The “developed surface” or “fracture surface” formed when the fine particles collide at high speed is the “new surface” in which the atoms that existed inside the original fine particles and were bonded to other atoms were exposed. Is formed. This new surface having a high surface energy and active bonds with the surface of the substrate 100 and other fine particles, thereby forming a dense brittle material structure having extremely high adhesion strength to the substrate 100.

  In the present embodiment, the fact that the aerosol particles are crushed and deformed on the base material means that the raw material particles used as the raw material and the crystallite size of the formed brittle material structure are X-rays. This can be confirmed by measuring with a diffraction method or the like. That is, in many cases, the crystallite size of the brittle material structure formed by the AD method is smaller than the crystallite size of the small fine particles SP10 used as a raw material.

  Furthermore, the crystals often have substantially no crystal orientation, and there is substantially no grain boundary layer composed of a glass layer at the interface between the crystals. The brittle material structure formed by the AD method is clearly different from the so-called “compact” in which the particles are packed by pressure and kept in physical form, and possesses sufficient strength. Yes.

Examples of specific conditions of the method for manufacturing a brittle material structure according to the embodiment of the present invention are as follows.
First, it is desirable that the injection speed at the nozzle outlet when injecting the aerosol is 20 m / second or more. When the spray speed is 20 m / sec or less, the powder particles are not sufficiently crushed and deformed when they collide with the base material, so that the adhesion strength between the base material 100 and the deposit D10 is weak and easy to peel.

  At that time, by setting the interval of intermittent aerosol injection to 0.1 seconds or more, a dense brittle material structure can be manufactured at a high deposition rate according to the mechanism described above with reference to FIGS. If the interval between the intermittent injections is 0.1 seconds or less, the stagnation regions B10 and B20 cannot be sufficiently disappeared, and the growth rate of the deposit may be reduced, or the density of the film-like body may be reduced. is there. Further, when the interval between intermittent injections is about 10 seconds or more, the production efficiency is lowered.

Next, a manufacturing apparatus suitable for use in the manufacturing method of the brittle material structure of the present embodiment will be described.
FIG. 8 is a schematic view illustrating the basic configuration of a brittle material structure manufacturing apparatus according to an embodiment of the invention.
The manufacturing apparatus of this specific example includes a high-pressure gas source 1, a pressure regulating valve 2, a solenoid valve 3, a timer 4, a solid-gas mixer 5, a nozzle 6, and an XY moving table on which a substrate 100 is placed. 7, and a control unit 8 that controls the timer 4 and the XY moving table 7. As the high-pressure gas source, a compressor, a gas cylinder filled with gas at a high pressure, or the like can be used. A high-pressure gas is supplied from the high-pressure gas source 1 and the pressure is adjusted by the pressure adjustment valve 2. An electric signal for intermittently supplying gas from the timer 4 controlled by the control unit 8 is sent to the electromagnetic valve 3, and the gas flow is opened and closed by the electromagnetic valve 3, and gas is supplied to the solid-gas mixer 5. Supply intermittently.

  The solid-gas mixer 5 contains powder containing a brittle material. When gas is introduced through the electromagnetic valve 3, an aerosol in which fine particles are dispersed is formed. The formed aerosol is jetted from the nozzle 6 to the base material 100 placed on the XY moving table 7. The XY moving table 7 moves intermittently or continuously under the control of the control unit 8. A film-like body containing a brittle material can be formed on the surface of the substrate 100 by intermittently or continuously moving the XY moving table 7 while spraying aerosol.

  As the gas supplied from the high-pressure gas 1, various gases such as air, nitrogen, argon, and helium can be used. Moreover, the nozzle outlet at the tip of the nozzle 6 can be formed in a slit shape of about 0.4 × 10 millimeters, for example. In addition, as shown in FIG. 8, when there is a certain space volume between the solenoid valve 3 and the jet outlet of the nozzle 6, the waveform of intermittent injection becomes sluggish for convenience of using compressible gas, Even when the electromagnetic valve 3 is closed, a small amount of gas may be injected, so-called “pulsating injection”. Even in such a case, as long as the mechanism described above with reference to FIG. 6 and the like is substantially working, this is included in the intermittent injection of the present invention.

  9 to 14 are schematic views illustrating an intermittent injection mechanism that can be used in this embodiment.

FIG. 9 is a schematic diagram illustrating a first specific example of the intermittent injection mechanism.
In this specific example, a circular shutter 12 having a notch is provided in front of the nozzle 6. The nozzle 6 is supplied with aerosol in the direction of arrow A, and ejects the aerosol in the direction of arrow B from the slit-shaped jet outlet 6A. The shutter 12 is rotated in the direction of arrow A (or the opposite direction) by the motor 13 and intermittently shields the aerosol ejected from the nozzle 6 in the direction of arrow B. In this way, it becomes possible to inject aerosols intermittently.

FIG. 10 is a schematic diagram illustrating a second specific example of the intermittent injection mechanism.
In this specific example, a substantially rectangular shutter 15 is provided in front of the nozzle 6. The shutter 15 is reciprocated in the direction of arrow C by the motor 13 to intermittently shield the jet outlet 6 </ b> A of the nozzle 6. In this way, it becomes possible to inject aerosols intermittently.

FIG. 11 is a schematic diagram illustrating a third specific example of the intermittent injection mechanism.
In the nozzle 6, aerosol is introduced in the direction of arrow A, and the aerosol is ejected in the direction of arrow B. A flex tube 17 for sending aerosol to the nozzle 6 is connected. The flex tube 17 is made of a flexible material such as rubber or resin and can be deformed. By sandwiching the flex tube 17 with a plurality of eccentric cams 18 that can be rotated by the motor 13, it is possible to intermittently supply aerosol to the nozzle 6.

FIG. 12 is a schematic cross-sectional view illustrating a fourth specific example of the intermittent injection mechanism.
In this specific example, an electromagnetic solenoid 20 that reciprocates linearly in the injection path of the nozzle 6 is provided. A slide valve seat 22 is attached to the tip of the drive shaft 21 of the solenoid 20 and is movable in the direction of arrow C. FIG. 12 shows a state in which the slide valve seat 22 blocks the aerosol inlet 6 </ b> B of the nozzle 6. When the slide valve seat 22 moves upward in the figure, the aerosol inlet 6B is opened and the aerosol is jetted from the jet outlet 6A. By reciprocatingly sliding the slide valve seat 22 by the solenoid 20, it becomes possible to inject aerosol intermittently.

FIG. 13 is a schematic diagram illustrating a fifth specific example of the intermittent injection mechanism.
In this specific example, at least a part of the nozzle 6 is formed of a flexible material such as rubber or resin, and the position or orientation of the jet outlet 6A can be changed by deforming it as illustrated in FIG. A switching device 22 that reciprocates linearly is connected to the nozzle 6, and the tip of the nozzle 6 reciprocates linearly in conjunction with the operation of the switching device 22. For example, while continuously ejecting aerosol from the nozzle 6, the nozzle 6 is stopped at a first position 100 </ b> A and a second position 100 </ b> B on the base material 100 for a predetermined time in FIG. 13. Thus, aerosol can be ejected in pulses at these two locations. At this time, by moving the substrate 100 intermittently or continuously in conjunction with the reciprocating linear motion of the nozzle 6, a thick film-like body can be deposited on the surface of the substrate 100 over a wide range.

FIG. 14 is a schematic diagram illustrating a sixth specific example of the intermittent injection mechanism.
In this specific example, a slide valve seat 22 that reciprocally slides on the drive shaft 21 of the electromagnetic solenoid 20 is provided on the nozzle 6 in the same manner as described above with respect to the fourth specific example. The nozzle 6 is provided with a bypass outlet 6C.

  FIG. 14A shows a state in which the aerosol inlet 6B communicates with the bypass outlet 6C. That is, the slide valve seat 22 is in a state of closing the nozzle outlet 6A. At this time, the aerosol introduced into the aerosol inlet 6B is not ejected from the jet outlet 6A but is discharged through the bypass outlet 6C. Then, when the slide valve seat 22 slides in the direction shown by the arrow C1 from the state shown in FIG. 14A, the bypass outlet 6C is closed as shown in FIG. 14B, and the aerosol is introduced. The mouth 6B communicates with the jet outlet 6A. That is, aerosol is jetted toward the base material from the nozzle outlet 6A. Thereafter, when the slide valve seat 22 slides in the direction of the arrow C2, as shown in FIG. 14A again, the aerosol introduction port 6B communicates with the bypass outlet 6C.

  That is, in this specific example, aerosol can be intermittently injected from the jet outlet 6A by the reciprocating motion of the slide valve seat 22 in the directions of the arrows C1 and C2. Moreover, in the state where the aerosol is not injected from the jet outlet 6A, it is discharged from the bypass outlet 6C. That is, a constant amount of aerosol can be continuously supplied to the nozzle 6 from an aerosol supply mechanism (not shown). As a result, the rise when the aerosol is jetted in a pulse manner is good.

FIG. 15 is a schematic diagram illustrating a seventh specific example of the intermittent injection mechanism. That is, FIG. 5A is a plan view of the nozzle as viewed from the direction of the jet port, and FIGS. 5B and 5C are longitudinal sectional views in the operating state.
In this specific example, a flow path switching valve 24 that can change the injection gas flow path in the nozzle 6 is provided. The flow path switching valve 24 is connected to a switching device 25 outside the nozzle. By driving the switching device 25, the flow path switching valve 24 is appropriately moved in the direction of arrow A in FIG. 15A, and pseudo continuous intermittent injection is obtained even if continuous injection is continued. That is, as shown in FIGS. 15A and 15B, aerosols can be alternately injected from two different locations in two different directions. As a result, intermittent injection can be alternately performed at two different locations on the surface of the base material, as described above with reference to the fifth specific example. Then, by moving the substrate 100 intermittently or continuously in conjunction with the operation of the flow path switching valve 24, a thick film of brittle material over a wide range even under atmospheric pressure or a pressure close thereto. Is obtained.

The specific examples of the intermittent injection mechanism that can be provided in the present invention have been described above.
Next, embodiments of the present invention will be described in more detail with reference to examples and comparative examples implemented by the present inventors.

(First embodiment)
First, as a first example of the present invention, an aerosol obtained by mixing fine particles having a small particle diameter and fine particles having a large particle diameter was intermittently ejected to form a deposit.
Specifically, aluminum oxide Al ₂ O ₃ as large fine particles and yttrium oxide (yttria) Y ₂ O ₃ as small fine particles are weighed so as to have a predetermined weight ratio, and these powders are mixed and stirred. A uniform mixed powder was prepared (preparation step).
Next, the solid-gas mixer of the brittle material structure manufacturing apparatus described above with reference to FIG. 8 is filled, compressed air is supplied to the solid-gas mixer 5, aerosol is generated in the solid-gas mixer 5, and atmospheric pressure Below, it sprayed intermittently to five places on the surface of the base material 100 from the nozzle 6 (injection process), and the film-form body which consists of a brittle material was manufactured.
The quality of the brittle material film thus obtained was evaluated by identifying the appearance, the surface profile of the deposit, and the constituent components (evaluation step).

  Detailed conditions of the present embodiment will be described below.

Preparation step: As the aluminum oxide Al ₂ O ₃ powder, one having a purity of 99.8% and an average particle size of 5.8 μm was used. As the yttrium oxide Y ₂ O ₃ powder, one having a purity of 99.5% and an average particle size of 0.39 μm was used. The weight ratio of aluminum oxide and yttrium _oxide, after adjusted to _{Al 2 O 3 / Y 2 O} 3 = 5~50, was mixed and stirred these raw material powders.

    Injection process: As the nozzle 6, a rectangular nozzle having an opening size of 0.4 mm × 10 mm was used. The pressure of the compressed air supplied from the high pressure gas source 1 was 0.6 MPa, and the material of the base material 100 was stainless steel (SUS304). The conditions for intermittent injection were three sets per shot, with one set of 0.5 second injection and 0.5 second stop. That is, the cumulative injection time per shot is 1.5 seconds. The substrate 100 was kept stationary relative to the nozzle 6 during one shot of intermittent injection. Then, a total of 5 shots were ejected on the surface of the substrate 100 for each shot while shifting by 2 millimeters. Here, the moving speed of the base material 100 was 25 millimeters per minute. In other words, 2 millimeters were shifted in 4.8 seconds.

    Evaluation process: The appearance of the deposit was observed by macroscopic and close-up photography with a camera. In addition, the surface profile and thickness of the deposit are measured using a stylus roughness tester Surfcom 130A manufactured by Tokyo Seimitsu Co., Ltd., and the components of the brittle material film are identified by the X-ray diffraction method. did.

FIG. 16A is an external view photograph of a deposit of brittle material formed in this example.
Five deposits can be confirmed on the surface of the substrate 100 at intervals of 2 millimeters. These deposits are formed in a shape corresponding to the shape of the ejection port of the nozzle 6. Here, the injection was performed sequentially from A to A ′.

FIG. 16B is a graph illustrating the surface profile of the deposit measured along the line AA ′ shown in FIG.
It was confirmed that each deposit had an isosceles triangular cross-sectional shape and a thickness of about 10 to 20 μm. The results of X-ray diffraction revealed that these deposits consisted of yttrium oxide and contained almost no aluminum oxide. That is, it is considered that this is because aluminum oxide having a large average particle diameter of 5.8 μm has a large etching action due to the blast effect, and as a result, it is difficult to deposit on the surface of the substrate 100.

  As described above, according to the present example, a deposit made of a brittle material having a thickness of 10 to 20 μm could be formed in an extremely short spray time of 1.5 seconds at an atmospheric pressure.

( Reference example)
Next, as a reference example of the present invention, the same preparation powder and manufacturing apparatus as those in the first example described above were used, and the substrate 100 was shifted by 0.5 mm under atmospheric pressure, and shots were intermittently performed. .

FIG. 17A is an appearance photograph of the deposit formed in this reference example. It can be seen that a continuous film-like deposit is formed on the surface of the substrate 100. Here, aerosol injection was performed from A to A ′.

Moreover, FIG.17 (b) is a graph showing the surface profile of the deposit on the AA 'line represented to Fig.17 (a). Although the deposit formed in this reference example has some unevenness, it was confirmed that the deposit was continuously formed in a film shape on the surface of the substrate 100 and the average thickness was about 10 μm. In this way, by setting the interval for each shot as appropriate, the deposits for each shot are formed adjacent to each other or overlapped, resulting in the formation of a continuous film-like thick deposit even under atmospheric pressure. I was able to confirm that I could do it.

Also in this reference example, as a result of X-ray diffraction, it was confirmed that the formed deposit was mainly composed of yttrium oxide.

(First comparative example)
Next, as the first comparative example of the present invention, the same preparation powder and manufacturing apparatus as those of the first and reference examples described above are used, and the substrate 100 is moved while continuously injecting aerosol under atmospheric pressure. I tried to deposit. That is, in this comparative example, continuous injection was carried out while scanning aerosol on the surface of the substrate 5 times or 10 times (injection step). And the thickness of the deposit consisting of the formed brittle material was evaluated by the same method as the first and reference examples. The detailed conditions of this comparative example are as follows.
Injection step: The pressure of compressed air was 0.6 MPa, the material of the base material was stainless steel (SUS304), and the scan speed of aerosol was 25 mm / min.

  FIG. 18A is a graph showing the surface profile of the deposit when the aerosol is scanned five times in this comparative example. That is, this figure is a surface profile of a deposit obtained by scanning the same portion five times while continuously injecting aerosol onto the surface of the substrate 100.

  From this result, it is understood that the average thickness of the deposit is about 4.5 μm. In addition, it can be seen that there is a portion (arrow A) having a peak thickness with a film thickness of approximately 20 μm at the left end where the aerosol is first injected. As described above with reference to FIG. 2, this portion is a portion accumulated from the start of aerosol injection until the gas stagnation region is formed, and until the steady gas flow is formed. It can be seen that a very high deposition rate is obtained during this period.

  On the other hand, FIG. 18B is a surface profile of the deposit when the aerosol is scanned 10 times in this comparative example. Similar to the one shown in FIG. 1A, a peak of thickness (arrow A) is observed at the part where the aerosol injection is first started, but the average thickness at the other part is still 4.5 μm. Degree. That is, it was found that the average thickness hardly changed even when the aerosol was scanned 5 times or 10 times. As described above with reference to FIGS. 2 to 4, a gas stagnation region is formed in a steady state under atmospheric pressure, and the density of the deposit composed of small fine particles (yttrium oxide) contributing to the deposition is low. This is probably because the growth of the deposit becomes difficult because the etching action due to the blast effect of large particles (aluminum oxide) and the growth of the deposit are balanced.

  On the other hand, the peak-shaped thickness portion (arrow A) that can be seen at the left end of FIGS. It is thought that since the collision occurred and a dense deposit was formed, it was difficult to be etched by the subsequent blast effect. However, the thickness peak of FIG. 18B is lower than that of FIG. 18A, and it is estimated that the etching progressed gradually by scanning 10 times.

  As described above, in this comparative example, as a result of scanning while aerosol was continuously injected under atmospheric pressure, the growth of the deposits stopped, and the thickness of the deposits increased even after repeated scanning. It turned out to be difficult. That is, it was confirmed that it was difficult to form a thick deposit when aerosol was continuously sprayed.

(Third embodiment)
Next, as a third example of the present invention, an aerosol using only small fine particles was intermittently jetted under atmospheric pressure to deposit a brittle material.
That is, an aerosol was formed using barium titanate having a purity of 99.9% and an average particle size of 0.2 μm. The manufacturing apparatus used is the same as that of the first embodiment described above, but the intermittent condition of the injection process is that the injection is performed for 1.0 second and then the stop is performed for 1.0 second as one set. Five sets of injections were performed. Then, 5 shots were sprayed on the surface of the substrate 100 at intervals of 2 mm. Evaluation of the formed brittle material deposit was performed by the same method as in the first example.

  FIG. 19A is an external view photograph of a deposit formed by intermittent injection. It can be confirmed that deposits are formed at six locations on the surface of the substrate 100. Here, the aerosol was sprayed from A to A ′.

  FIG. 19B is a graph showing the surface profile measured along the line A-A ′ shown in FIG. All of the deposits have an isosceles triangular cross-sectional shape, and it was confirmed that the thickness reached about 2.0 μm. That is, according to this example, it was confirmed that a deposit made of a brittle material could be formed under atmospheric pressure even when intermittent injection was performed using only small particles.

(Second comparative example)
Next, as a comparative example to the above-described third example, an attempt was made to deposit brittle material by continuously injecting aerosol using only small fine particles under atmospheric pressure.

That is, in the present comparative example, the same aerosol composed of fine particles of barium titanate as in the third example was used. Although the manufacturing apparatus and its conditions were the same as those of the first comparative example 1 described above, only the number of scans was five, and an attempt was made to form a deposit made of a brittle material. FIG. It is an external appearance photograph showing the surface of the base material 100 of. As shown in the figure, in this comparative example, an apparent continuous contrast is observed in the area irradiated with the aerosol, but this is a change to the extent that the surface of the substrate 100 is slightly colored. Not too much.

  FIG. 20B is a graph showing the surface profile measured along the line A-A ′ in FIG. A peak having a thickness of less than 1 μm is observed at the left end where the aerosol is first injected, but in other portions, a deposit having a significant thickness is not formed. That is, it has been found that it is difficult to form a continuous film-like deposit even when aerosols using small fine particles are continuously ejected under atmospheric pressure. On the other hand, according to the present invention, as described above with respect to the third embodiment, even when only small particles are used, the aerosol is intermittently ejected to obtain a thickness under atmospheric pressure. It is possible to form a deposit with a certain thickness.

  The embodiments of the present invention have been described above with reference to specific examples. However, the present invention is not limited to these specific examples.

  For example, the spray angle of the aerosol with respect to the base material is not necessarily perpendicular, and the aerosol may be sprayed in an oblique direction with respect to the surface of the base material. Further, the atmosphere for forming the deposit is not limited to atmospheric pressure, and it is of course effective for implementation in a vacuum environment under reduced pressure with a nozzle installed in a chamber or the like.

  Further, the type of brittle material used in the method and apparatus for manufacturing the brittle material structure of the present invention, its particle size, concentration, type and pressure of gas to be mixed, flow rate, type and size of material used as a substrate, Various parameters such as shape, distance from nozzle to base material, injection time and interval, and intermittent injection mechanism are not limited to the specific examples described above. As long as it has the gist of the present invention, it is included in the scope of the present invention.

It is a schematic diagram showing the manufacturing method of the brittle material structure concerning embodiment of this invention. It is a schematic diagram for demonstrating the change of the flow of gas immediately after starting injection of gas from a nozzle to the base-material surface under atmospheric pressure. It is a schematic diagram showing the deposition behavior when an aerosol containing small fine particles is jetted onto a substrate. It is a schematic diagram showing the deposition behavior when an aerosol containing large fine particles is used. It is the graph which illustrated transition of the deposition rate with respect to aerosol injection time ST under the pressure near atmospheric pressure. It is the schematic diagram which represented continuously the behavior of deposition when aerosol is intermittently injected from the nozzle to the base-material surface in embodiment of this invention. It is the schematic diagram which represented continuously the behavior of deposition when aerosol is intermittently injected from the nozzle to the base-material surface in embodiment of this invention. It is a schematic diagram which illustrates the basic composition of the manufacturing apparatus of the brittle material structure concerning embodiment of this invention. It is a schematic diagram showing the 1st specific example of an intermittent injection mechanism. It is a schematic diagram showing the 2nd specific example of an intermittent injection mechanism. It is a schematic diagram showing the 3rd specific example of an intermittent injection mechanism. It is a schematic diagram showing the 4th example of an intermittent injection mechanism. It is a schematic diagram showing the 5th example of an intermittent injection mechanism. It is a schematic diagram showing the 6th specific example of an intermittent injection mechanism. It is a schematic diagram showing the 7th specific example of an intermittent injection mechanism. (A) is the external appearance photograph of the deposit of the brittle material formed by the present Example, (b) is the surface profile of the deposit measured along the AA 'line represented to (a). FIG. (A) is the external appearance photograph of the deposit formed in a present Example, (b) is a graph showing the surface profile of the deposit on the AA 'line represented to Fig.17 (a). . (A) is a graph showing the surface profile of the deposit when the aerosol is scanned 5 times in the comparative example, and (b) is the surface of the deposit when the aerosol is scanned 10 times in this comparative example. It is a profile. (A) is the external appearance photograph of the deposit formed by intermittent injection, (b) is a graph showing the surface profile measured along the AA 'line represented to Fig.19 (a). . (A) is an external appearance photograph showing the surface of the base material 100 after aerosol injection, (b) is a graph showing the surface profile measured along the AA 'line of FIG. 19 (a). is there.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 High pressure gas source 2 Pressure regulating valve 3 Solenoid valve 4 Timer 5 Solid gas mixer 6 Nozzle 6A Jet 6B Aerosol inlet 6C Bypass outlet 7 Moving stand 8 Control part 12 Shutter 13 Motor 15 Shutter 17 Flex pipe 18 Eccentric cam 20 Electromagnetic solenoid 21 Drive shaft 22 Switching device 22 Slide valve seat 24 Flow path switching valve 25 Switching device 100 Base material 200 Nozzle

Claims (2)

The fine particles are sprayed from the nozzle toward the base material so that the aerosol in which the fine particles are dispersed in the gas collides with the base material while relatively displacing the nozzle and the base material. A method for producing a brittle material structure for forming a composite structure of a brittle material structure composed of the above-mentioned constituent material and the base material,
The collision of the aerosol with the substrate is performed under an atmosphere of substantially atmospheric pressure,
A first step of injecting the aerosol toward the substrate for a first predetermined time;
A second step of stopping injection of the aerosol onto the substrate for a second predetermined time;
With
The aerosol is intermittently collided with the base material by alternately repeating the first step and the second step,
The method for manufacturing a brittle material structure, wherein the first predetermined time is 1 second or less.   The method for manufacturing a brittle material structure according to claim 1, wherein the second predetermined time is 0.1 second or more.