JP2016160446A - Thermal spraying material and manufacturing method therefor, thermal spraying method and thermal spraying product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily perform thermal spraying by using fine particles which is conventionally difficult to handle.SOLUTION: Fine particles of resin including fine particles of ceramic or metal are used as a thermal spraying material and then thermal spraying can be easily performed by using the fine particles which are conventionally difficult to handle. In manufacture of the thermal spraying material, when the fine particles are dispersed in liquid resin, an intermediate substance prepared by adding the fine particles to the liquid resin having room-temperature curing properties is agitated for a predetermined unit agitation time and then cooled (steps S121, S122). Then the steps S121, S122 are repeated until a total agitation time of the intermediate substance reaches a necessary agitation time or longer (step S123). By the above, the liquid room-temperature curing resin is suppressed from being cured before dispersion of the fine particles, and thereby the thermal spraying material can be easily manufactured in which the fine particles are dispersed in the room-temperature curing resin in a monodisperse state.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a technique for forming a coating on a substrate by plasma spraying, flame spraying, or laser spraying.

  In plasma spraying, flame spraying, and laser spraying, powder materials such as metals and ceramics are introduced into a high-temperature plasma flow, flame flow, or focused laser beam, and molten material particles are sprayed onto the substrate surface to deposit them. To form a coating. These thermal spraying methods have been established as industrial manufacturing techniques, and it is not necessary to arrange an object in a sealed space, and can be applied to large areas and long objects.

  On the other hand, layered structures using fine particles called nanoparticles are applied to various fields and products such as coatings and devices. These are usually formed with a precise composition and structure by an aerosol deposition method (AD method), a chemical vapor deposition method (CVD method), or the like. However, these methods cannot be used in an atmospheric environment, and are currently unsuitable for continuous production, application to large, long objects, and mass production thereof.

  Therefore, if the existing thermal spraying method can be used by using nanoparticles as a material, a coating such as a dense coating layer can be applied to a larger production quantity or to a longer and larger object in a short time. Forming with is realized. In addition to the formation of dense coatings by thermal spraying technology using nanoparticles, conventional thermal spraying, such as the formation of a layer in which multiple types of material particles are uniformly mixed, and the thermal insulation function including nano-sized pores, etc. It is also possible to produce a film having performance and functions that could not be achieved.

  However, the lower limit of the particle size of the material powder to be introduced into the high temperature part such as plasma or flame that becomes the thermal spraying heat source is about 1 to 5 μm. When the particle size of the material powder is smaller than the lower limit value, there may be a case where clogging occurs in the transport tube for introduction into the high temperature part. In addition, the nanoparticles are usually aggregated and present in a size of several tens of μm at room temperature and atmospheric pressure. When such agglomerated particles are introduced into the plasma flow, they become agglomerated droplets when melted in a high-temperature plasma part, and do not reach the substrate as nanoparticles. As a result, the characteristics as nanoparticles cannot be utilized.

  In the flame spraying disclosed in Patent Document 1, ceramic particles having a particle size of 0.1 to 5 μm are dispersed in advance in a solvent such as alcohol or kerosene to obtain a slurry. Then, thermal spraying is performed by injecting the slurry into the frame. However, in the method of Patent Document 1, when the particle size of the ceramic particles becomes small, it is not easy to uniformly disperse the ceramic particles in the solvent.

  On the other hand, in Non-Patent Document 1, a linear material is obtained by dispersing nanoparticles in a photocurable acrylic resin solvent and curing the resin in a linear shape using ultraviolet rays. Nanoparticles are uniformly dispersed in the linear material. Thereafter, the linear material is introduced into the plasma and plasma spraying is performed. As a result, it is possible to form a high-quality film on the substrate.

JP 2011-256465 A

Yasuhide Kirihara and two others, “Dense coating of ceramics on a practical alloy substrate by plasma spraying using fine nanoparticle wires”, Summary of the National Conference of the Japan Welding Society, Vol. 91, September 3, 2012, p. 372-373

  By the way, the method of Non-Patent Document 1 requires a linear material supply device and also requires optimization of the cross-sectional area and supply speed of the linear material. Furthermore, it is not easy to switch and use a plurality of materials during one thermal spraying process.

  The present invention has been made in view of the above-mentioned problems, and has as its main purpose to easily perform thermal spraying using fine particles that have been difficult to handle in the past.

  The invention according to claim 1 is a method for producing a thermal spray material used for plasma spraying, flame spraying or laser spraying, and a) a step of dispersing ceramic or metal fine particles in a liquid resin having room temperature curing properties. And b) crushing the cured product obtained by curing the mixture obtained in the step a) to obtain a thermal spray material that is a particle having a particle size larger than the fine particles, and the step a) includes the step a1. ) A step of stirring the intermediate substance obtained by adding the fine particles to the liquid resin for a predetermined unit stirring time; a2) a step of cooling the intermediate substance after the a1) step; and a3) the intermediate substance. And a step of repeating the step a1) and the step a2) until the total stirring time becomes equal to or longer than the required stirring time.

  Invention of Claim 2 is a manufacturing method of the thermal spray material of Claim 1, Comprising: In the said a2) process, the said intermediate substance is cooled with a refrigerant | coolant lower than normal temperature.

  Invention of Claim 3 is a manufacturing method of the thermal spray material of Claim 1 or 2, Comprising: In said a2) process, the said intermediate substance is cooled until the temperature of the said intermediate substance becomes below stirring restart temperature. Is done.

  Invention of Claim 4 is a manufacturing method of the thermal spray material in any one of Claim 1 thru | or 3, Comprising: The average particle diameter of the said microparticles | fine-particles by a laser diffraction and scattering method or a dynamic light scattering method is 25 nm It is 1000 nm or less.

  Invention of Claim 5 is a manufacturing method of the thermal spray material in any one of Claim 1 thru | or 4, Comprising: A main ingredient and a hardening | curing agent are mixed and stirred before the said a) process. The method further includes the step of generating the liquid resin.

  The invention according to claim 6 is manufactured by the manufacturing method according to any one of claims 1 to 5.

  Invention of Claim 7 is a thermal spraying method, Comprising: The process which prepares the thermal spray material manufactured with the manufacturing method in any one of Claim 1 thru | or 5, and e) The said thermal spray material is used. And performing a plasma spraying, a flame spraying, or a laser spraying to bond the heated fine particles on a substrate to form a coating.

  Invention of Claim 8 is a thermal spraying method of Claim 7, Comprising: It is manufactured with the manufacturing method in any one of Claim 1 thru | or 5, and forms with the material different from the said microparticles | fine-particles. A step of preparing another thermal spraying material containing the other fine particles formed, and g) after the step e), plasma spraying, flame spraying or laser spraying is performed using the other thermal spraying material. A step of forming another film by bonding the other fine particles on the film formed in the step.

  According to the ninth aspect of the present invention, a coating is formed on a substrate by the thermal spraying method according to the seventh or eighth aspect.

  According to the present invention, thermal spraying can be easily performed using fine particles that have been difficult to handle conventionally.

It is a figure which shows the structure of a thermal spraying apparatus. It is a figure which shows the flow of manufacture of a thermal spray material. It is a figure which shows a part of flow of manufacture of a thermal spray material. It is a figure which shows the cross section of hardened | cured material. It is a figure which shows a part of flow of manufacture of a thermal spray material. It is a figure which shows the flow of a thermal spraying operation | work. It is a figure which shows a part of flow of manufacture of a thermal spray material. It is a figure which shows the cross section of hardened | cured material. It is a figure which shows the cross section of hardened | cured material. It is a figure which shows the cross section of hardened | cured material. It is a figure which shows the cross section of hardened | cured material. It is a figure which shows the other example of a thermal spraying apparatus. It is a figure which shows the flow of a thermal spraying operation | work.

  FIG. 1 is a diagram showing a configuration of the thermal spraying apparatus 1. The thermal spraying apparatus 1 is an apparatus that performs plasma spraying on a base material 9, and includes a thermal spray gun 11, a gas supply unit 12, a material storage unit 13, an air supply unit 14, and a material conveyance unit 15. The thermal spray gun 11 generates a plasma flare 8. The gas supply unit 12 supplies argon gas to the thermal spray gun 11. The gas supplied by the gas supply unit 12 is not limited to argon gas, but may be helium gas or other gas. The material storage unit 13 stores a thermal spray material used for thermal spraying. The air supply unit 14 supplies air to the material conveyance unit 15. The material transport unit 15 supplies the thermal spray material into the plasma flare 8 using the air from the air supply unit 14. Gas used for conveyance (hereinafter referred to as “carrier gas”) is not limited to air.

  The thermal spray gun 11 is an ejection nozzle that performs thermal spraying. An argon gas flow path 21 is provided in the spray gun 11. A cathode 22 is disposed at the center of the channel 21, and an anode 23 is disposed on the downstream side of the cathode 22 so as to surround the channel. The plasma flare 8 is ejected from the ejection port 24 by the discharge between the cathode 22 and the anode 23.

  The material transport unit 15 includes a fixed amount supply unit 31 and a transport pipe 32. The fixed amount supply unit 31 takes out a certain amount of sprayed material per unit time from the material storage unit 13 and merges it with the carrier gas. An end portion of the transfer pipe 32 serves as an ejection port 33, and the spray material is ejected from the ejection port 33 together with the carrier gas. The thermal spray material is introduced vertically from the side in the traveling direction of the plasma flare 8 toward the center of the plasma flare 8.

  The thermal spray material is powder, and each particle has a size that does not clog the conveying tube 32. As will be described later, each particle is a resin containing finer fine particles. The fine particles contained in the thermal spray material are ceramic particles or metal particles. The resin of the thermal spray material is burned out by the plasma flare 8, and fine particles in a molten state or a semi-molten state flow together with the plasma flare 8 toward the substrate 9. As a result, fine particles are deposited on the substrate 9, and a film is formed.

  Next, the production of the thermal spray material will be described with reference to an example of the thermal spray material actually produced (hereinafter referred to as “production example”). FIG. 2 is a diagram showing a flow of manufacturing a thermal spray material. First, ceramic particles or metal particles are prepared as fine particles, and a resin having room temperature curability is prepared as a liquid resin. A resin having room temperature curability is a resin that cures naturally at room temperature (for example, an environment having a temperature of 15 to 35 degrees).

  The fine particles used in the production examples are zirconia particles having an average particle diameter of 200 nm (trade name “KZ-8YF” manufactured by Kyoritsu Material Co., Ltd.). The average particle diameter here is the median diameter (d50) calculated from the particle size distribution obtained by the laser diffraction / scattering method. In the following description, the zirconia fine particles are simply referred to as “fine particles”.

The material of the fine particles is not limited to the above-described zirconia (ZrO ₂ ), and may be variously changed. For example, as the ceramic material of fine particles, aluminum oxide, silicon oxide, mullite (Al ₂ O ₃ · SiO ₂ ), zirconium oxide, zircon (ZrO ₂ · SiO ₂ ), forsterite (2MgO · SiO ₂ ), steatite ( MgO · SiO ₂ ), barium titanate (BaTiO ₃ ), lead zirconate titanate (Pb (Zr, Ti) O ₃ ), titanium oxide, zinc oxide, calcium oxide, magnesium oxide, chromium oxide, manganese oxide, iron oxide Oxides and composite oxides including nickel oxide, copper oxide, gallium oxide, germanium oxide, yttrium oxide, silver oxide, cobalt oxide, tungsten oxide, vanadium oxide, barium oxide, etc .; aluminum nitride, silicon nitride, etc. Nitride group including: Carbide group including silicon carbide, etc .; W One or more selected from a cermet group including C / C, WC / Ni, WC / CrC / Ni, WC / Cr / Co, CrC / NiCr, sialon (SiN ₄ · Al ₂ O ₃ ), etc. Is available.

  Various materials such as aluminum and copper can be used as the material for the fine particles in the case of metal. A plurality of types of metals may be mixed as the fine particle material. Furthermore, ceramics and metal may be mixed as the material of the fine particles.

The average particle diameter of the fine particles may be changed variously. However, the average particle diameter of the fine particles is so small that it is difficult to handle the fine particles as they are by air conveyance in the thermal spraying apparatus 1, and is the so-called nanoparticle size. Specifically, the average particle size of the fine particles is from 25 nm to 1000 nm (25 × 10 ⁻⁹ m to 1000 × 10 ⁻⁹ m) as determined by the laser diffraction / scattering method or the dynamic light scattering method. is there. When the average particle size of the fine particles is less than 25 nm, the amount of fine particles that can maintain a monodispersed state in the resin is reduced, so that the specific gravity of the thermal spray material becomes small, and it becomes difficult to supply to the center of the plasma flare. On the other hand, if the average particle size of the fine particles exceeds 1000 nm, the particles tend to settle when mixed with the resin, and it becomes difficult to maintain a monodispersed state. Preferably, the average particle diameter is 50 nm or more and 500 nm or less which is easily available. When measurement by the laser diffraction / scattering method is difficult, measurement may be performed by the dynamic light scattering method. The average particle diameter may be the one shown by the fine particle manufacturer.

  In the production example, a multi-component resin (so-called two-component resin) that cures at room temperature by mixing a main agent and a curing agent (so-called catalyst) is used as a liquid room-temperature curable resin. . Curing of the two-component resin is promoted by an increase in temperature in normal temperature and in a temperature range that is somewhat higher than normal temperature (for example, a temperature range that is normal temperature or higher and approximately 10 degrees higher than normal temperature). The specific resin used in the production example is a polyester two-component resin (manufactured by Marumoto Struers Co., Ltd., trade name “cold embedding resin No. 105”). As the room temperature curable resin, various resins may be used as long as they are mainly composed of organic substances, and acrylic resins and epoxy resins may be used. Further, as the room temperature curable resin, a moisture curable resin or a solvent volatile resin may be used.

  In the production of the thermal spray material, first, the main component of the room temperature curable resin and the curing agent are mixed and stirred in the container, thereby generating a liquid resin having room temperature curable properties (step S11). The temperature of the liquid resin is, for example, about 32 degrees (° C.). In the liquid resin, the main agent and the curing agent are mixed approximately evenly, and the curing of the resin is started. Agitation of the mixture of the main agent and the curing agent is performed manually using a stirring rod in a plastic container having a diameter of 50 mm and a depth of 80 mm, for example.

  Subsequently, the above-mentioned fine particles are dispersed in the liquid resin generated in step S11 (step S12). FIG. 3 is a diagram showing a detailed flow of step S12. Step S12 includes steps S121 to S123 shown in FIG. In step S12, first, the above-mentioned fine particles are added to a liquid resin having room temperature curing properties in the container to obtain an intermediate substance. The ratio of the fine particles contained in the intermediate substance is, for example, about 40% by volume. Then, the intermediate substance in the container is stirred for a predetermined unit stirring time (step S121).

  Stirring of the intermediate substance in step S121 is performed by, for example, a stirring / defoaming apparatus that involves rotation and revolution. The conditions of stirring and defoaming in the stirring and defoaming apparatus are 350 rpm for rotation and 1060 rpm for revolution. The unit stirring time is, for example, 30 seconds. In step S121, the temperature of the intermediate substance rises due to heat caused by fine particle friction, agitation / deaeration device, or the like. The temperature of the intermediate substance after step S121 is, for example, about 45 to 50 degrees. Even during the execution of step S121, the curing of the room temperature curable resin in the intermediate substance proceeds and is accelerated by the temperature rise.

  When step S121 is completed, the container containing the intermediate substance is taken out from the stirring / defoaming device, and the intermediate substance is cooled (step S122). In step S122, the intermediate substance is cooled by, for example, a refrigerant having a temperature lower than room temperature. In the production example, the intermediate substance is rapidly cooled by bringing the container containing the intermediate substance into contact with running water or ice having a temperature lower than room temperature. In other words, the intermediate substance indirectly contacts running water or ice having a temperature lower than normal temperature through the container. Thereby, hardening of the normal temperature curable resin in an intermediate substance is suppressed.

  The cooling of the intermediate substance in step S122 is performed, for example, until the temperature of the intermediate substance reaches a predetermined stirring restart temperature. The stirring restart temperature is, for example, a temperature not higher than about 10 degrees higher than normal temperature, specifically about 40 to 45 degrees. The cooling of the intermediate substance in step S122 may be performed for a predetermined cooling time, for example. The cooling time is, for example, about 60 seconds.

  When step S122 is completed, the total of the stirring time of the intermediate substance performed after the addition of the fine particles to the liquid resin (hereinafter referred to as “total stirring time”) is compared with a predetermined required stirring time. (Step S123). The required stirring time is longer than the unit stirring time. The necessary stirring time is, for example, 600 seconds. If the total stirring time is less than the required stirring time, the process returns to step S121, and the stirring of the intermediate substance for the unit stirring time and the cooling of the intermediate substance after stirring (steps S121 and S122) are performed.

  In step S12, steps S121 and S122 are repeated until the total stirring time of the intermediate substance is equal to or longer than the required stirring time. Thereby, a nano slurry in which fine particles, which are so-called nanoparticles, are uniformly monodispersed is obtained. The necessary stirring time is, for example, about 600 seconds. The required stirring time is determined based on, for example, a change with time in the viscosity characteristic of the intermediate substance obtained by experiments. Specifically, for example, the relationship between the stirring speed and the shear stress when the total stirring time is changed is obtained by experiment, and the total stirring time at which the state of hysteresis appearing in the viscosity curve hardly changes, or the total stirring The required stirring time may be obtained by adding a predetermined margin time to the time. Alternatively, the total stirring time at which the change in the thixotropy of the intermediate substance over time does not appear, or a value obtained by adding a predetermined margin time to the total stirring time may be set as the required stirring time.

  Here, the volume ratio of the fine particles in the nano-slurry can be variously changed. However, if the volume ratio is low, the deposition rate by thermal spraying is slowed, and the deposition efficiency is lowered. The upper limit of the volume ratio depends on the particle size and the size of solvent molecules entering between the particles. That is, for example, when the sphere has an ideal particle diameter of 150 nm, the thickness of the solvent molecules is 15 nm, and each particle is arranged on a lattice point of a hexagonal close-packed lattice, the filling rate of about 51% is maximized. Therefore, the maximum value of the filling rate varies depending on the conditions of the fine particles and the solvent. However, since the fine particles actually have a particle size distribution within a significant range and do not fit in an ideal arrangement, the actual filling rate is different from the theoretical value.

  Nano slurry which is the mixture produced | generated in step S12 is taken out from a container. In the nano slurry, the curing of the room temperature curable resin proceeds to some extent, and the nano slurry has a soft bowl shape. Therefore, the nano slurry in the container can be handled integrally. If a thermosetting resin is used instead of the room temperature curable resin, the mixture generated in step S12 is in the form of a whipped cream and is not easy to handle integrally. On the other hand, by using a room temperature curable resin as the liquid resin as described above, the nanoslurry can be handled integrally, and the nanoslurry can be easily taken out from the container. Moreover, since it can prevent (or suppress) that a part of nano slurry adheres and remains in a container at the time of taking out a nano slurry, the yield of a thermal spray material can also be improved.

  The nanoslurry taken out from the container is formed by being thinly stretched on, for example, paraffin paper. Then, the room temperature curable resin is cured as time passes, so that the nano slurry becomes a cured product while maintaining the monodispersed state of the fine particles (step S13). FIG. 4 is a cross-sectional view of the cured product observed with a scanning electron microscope. It can be confirmed from FIG. 4 that the cured product is in a monodispersed state in which the fine particles are dispersed in an independent state without contacting each other.

The above-described cured product (that is, a cured product obtained by curing the mixture obtained in step S12) is pulverized using, for example, a manual crusher or a vibration mill. The pulverized cured product (hereinafter also referred to as “pulverized product”) is fractionated using a sieve. Thereby, the thermal spray material which is a particle | grain with a larger particle diameter than the above-mentioned fine particle is obtained (step S14). In this Embodiment, the hardened | cured material after a grinding | pulverization is fractionated by the particle size range of 45 micrometers or more and less than 106 micrometers (45 * 10 < ^-6 > m or more and less than 106 * 10 < ^-6 > m) which is a predetermined target particle size range. .

The particle size range may be variously changed as long as it can be used in the thermal spraying apparatus 1. The particle size range can be defined by the sieve openings used for fractionation. The particle size of the particles obtained by pulverization of the cured product may be variously determined as long as it is larger than the contained fine particles. Preferably, the particle size range is 1 μm or more and 120 μm or less (1 × 10 ⁻⁶ m or more and 120 × 10 ⁻⁶ m or less). More preferably, the particle size of the pulverized particles is not less than 5 times the particle size of the fine particles, and from 5 μm to 120 μm from the viewpoint of easy air transfer with a thermal spraying apparatus.

  FIG. 5 is a diagram illustrating an example of a detailed flow of step S14. Step S14 includes steps S141 to S145 shown in FIG. In step S14, first, the cured product obtained in step S13 is roughly pulverized by a manual crusher to become a pulverized product having a particle size of less than 400 μm (step S141). The pulverized product obtained in step S141 is put on a sieve having an opening of 106 μm and fractionated by a vibration sieve using a sieve shaker (step S142). Preferably, a tapping member such as a tapping ball or a tapping block is put in the sieve together with the pulverized material. Thereby, clogging of the sieve is suppressed, and the pulverized product can be efficiently fractionated. Particles having a particle size of 106 μm or more remaining on the sieve (that is, residues) are pulverized again using a mill (steps S143 and S144) and fractionated again using the sieve (step S142). Then, pulverization by a mill and fractionation by sieving are repeated until the particle size of all the pulverized products becomes less than 106 μm (steps S142 to S144).

  Subsequently, the pulverized product obtained in steps S142 to S144 is put on a sieve having an opening of 45 μm and fractionated by a vibrating screen using a sieve shaker. In the same manner as described above, the tapping member is preferably put together with the pulverized product in the sieve. Thereby, clogging of the sieve is suppressed, and the pulverized product can be efficiently fractionated. Then, particles having a particle size of 45 μm or more (and less than 106 μm) remaining on the sieve are obtained as the thermal spray material that is particles within the target particle size range (step S145). Further, the over-pulverized particles that are particles having a particle size of less than 45 μm that have passed through the sieve (that is, particles having a particle size of less than the target particle size range) are recovered and used in the production of the thermal spray material after the second time described later. . The particle size of the excessively pulverized particles is equal to or larger than the particle size of the fine particles, and is usually larger than the particle size of the fine particles. Even in the over-pulverized particles, the fine particles are evenly dispersed. In step S145, the excessively pulverized particles separated from the thermal spray material by the sieve are collected in an aggregated state.

  In step S14, in order to confirm that the particle size of the pulverized material obtained in step S141 is less than 400 μm, the pulverized material is 400 μm between step S141 and step S142. It may be put on a sieve having a mesh opening and fractionated by a vibrating screen using a sieve shaker. If the pulverized product remains on the sieve, the remaining pulverized product is pulverized by a mill or the like until the particle size becomes less than 400 μm.

  The grinding by the mill in step S144 is performed for a predetermined grinding time, for example. The pulverization time of the cured product is determined in advance based on the ratio of the thermal spray material obtained in step S144 and the excessively pulverized particles (that is, the ratio to the cured product charged into the mill in step S144). Specifically, the cured product is pulverized while changing the pulverization time, and the particle size distribution of the pulverized product corresponding to each of a plurality of types of pulverization times is measured. Thereby, the ratio of the thermal spray material and the excessively pulverized particles respectively corresponding to a plurality of types of pulverization times is obtained. As the pulverization time is increased, the ratio of the thermal spray material and the excessively pulverized particles is increased. As the pulverization time is decreased, the ratio of the thermal spray material and the excessively pulverized particles is decreased.

  In the production of the thermal spray material, an increase in the efficiency of the production work is required by increasing the amount of the thermal spray material obtained in one step S144 and decreasing the number of repetitions of step S144. Further, by suppressing the amount of excessively pulverized particles generated in one step S144, an improvement in the ratio of the thermal spray material obtained in step S14 to the entire cured product (that is, the yield of the thermal spray material) is also required. An appropriate grinding time that satisfies these requirements is determined as the grinding time in step S144. The pulverization time in step S144 is 40 seconds, for example.

  FIG. 6 is a diagram showing a flow of thermal spraying by the thermal spraying apparatus 1. When the thermal spray material manufactured by the manufacturing method in steps S11 to S14 described above is prepared (step S21), the thermal spray material is filled in the material storage unit 13. (Step S22). Thereafter, plasma spraying is performed using the thermal spray material. Thereby, the heated fine particles are bonded on the base material 9, and a film is formed on the base material 9 (step S23). On the substrate 9, the fine particles are melt-bonded to form a dense film. Conditions may be set so that the fine particles reach the substrate 9 in a semi-molten state, and in this case, a porous film is formed.

  As described above, by using resin particles containing fine particles of ceramics or metal as a thermal spray material, so-called nanoparticles that have been difficult to handle in the past while utilizing a thermal spraying device having a structure similar to that of the prior art Even fine particles of a so-called size can be easily sprayed using the fine particles. As a result, an increase in cost required for thermal spraying can be suppressed, and a decrease in efficiency of thermal spraying work can be prevented. That is, even a large material can be constructed at a high production rate by thermal spraying technology. Furthermore, it is also possible to use, as industrial materials, materials that have dramatically improved physical and chemical properties such as nanocomposite materials and nanoporous materials that take advantage of nanoparticles.

  As described above, in the production of the thermal spray material, in step S12 (dispersion of the fine particles in the resin), the intermediate substance in which the fine particles are added to the liquid resin having room temperature curing property is used for a predetermined unit stirring time. After being stirred, the intermediate substance is cooled (steps S121 and S122). Then, steps S121 and S122 are repeated until the total stirring time of the intermediate substance is equal to or longer than the required stirring time (step S123).

  If the above-mentioned intermediate substance is continuously stirred for the necessary stirring time (that is, if the stirring is performed only for the necessary stirring time by one stirring), the temperature of the intermediate substance excessively rises during stirring. The resin is cured in a state where the dispersion of the resin is insufficient. If particles obtained by pulverizing a cured product with insufficient dispersion of fine particles are used as the thermal spray material, it is difficult to form a uniform coating on the substrate. On the other hand, in the manufacture of the above-mentioned sprayed material, steps S121 to S123 are performed in step S12, thereby suppressing the liquid room temperature curable resin from being hardened before the fine particles are dispersed. A thermal spray material dispersed in a monodispersed state can be easily manufactured. In addition, when a liquid resin having room temperature curing properties is used, the intermediate material is heated or irradiated with light when the intermediate material in which the fine particles are dispersed in a monodispersed state is cured. Since it is not necessary, the thermal spray material can be manufactured more easily.

  In step S122, the intermediate substance can be cooled quickly with a refrigerant (for example, running water or ice) lower than room temperature, so that the intermediate substance can be quickly cooled easily. Thereby, the progress of the curing of the intermediate substance after being stirred for the unit stirring time can be suppressed. Further, by indirectly contacting the intermediate substance with the refrigerant, the intermediate substance can be further rapidly cooled, and the curing of the intermediate substance after stirring can be further suppressed. Furthermore, in step S122, the intermediate substance is cooled until the temperature of the intermediate substance reaches the stirring restart temperature. For this reason, when an intermediate substance is stirred again after cooling, it can suppress that the temperature of an intermediate substance rises too much and hardening progresses too much.

  In the production of the above-mentioned sprayed material, the liquid resin having room temperature curable properties is obtained by mixing and stirring the main component of the room temperature curable resin and the curing agent before adding the fine particles to the resin in step S12. Is generated (step S11). Thus, the main agent and the curing agent are agitated before the addition of the fine particles to produce a liquid resin, whereby the fine particles are dispersed substantially uniformly in the room temperature curable resin having a substantially uniform material. be able to.

  In the actual production of the thermal spray material, steps S11 to S14 are repeated. FIG. 7 is a diagram showing a part of the flow of manufacturing the thermal spray material after the second time. In the production of the thermal spray material for the second and subsequent times, the excessively pulverized particles obtained at the time of pulverization of the cured product in step S14 of the production of the thermal spray material that has been performed are also added and dispersed in the liquid resin in step S12. The other manufacturing flow is substantially the same as steps S11 to S14 shown in FIGS.

  Specifically, in the production of the thermal spray material for the second and subsequent times, first, a liquid resin having room temperature curable properties is obtained by mixing and stirring the main component of the room temperature curable resin and the curing agent in a container. Is generated (step S11). Subsequently, fine particles and excessively pulverized particles are dispersed in the liquid resin generated in step S11 (step S12).

  Specifically, in step S12, first, as shown in FIG. 3, the above-described fine particles are added to a liquid resin having room temperature curing properties to obtain an intermediate substance, and the intermediate substance is stirred for a unit stirring time. (Step S121). The proportion of fine particles contained in the intermediate substance is about 40% by volume, as in the first thermal spray material production. When step S121 is completed, the intermediate substance is cooled (step S122). Then, the total stirring time of the intermediate substance is compared with the required stirring time, and steps S121 and S122 are repeated until the total stirring time becomes equal to or longer than the required stirring time (step S123).

  When the total stirring time is equal to or longer than the required stirring time and the dispersion of the fine particles in the intermediate material is completed, the over-pulverized particles obtained in the production of the sprayed material that has been carried out become the intermediate material (ie, Added to the mixture). The over-pulverized particles to be added are in an aggregated state as described above. In the production of the thermal spray material for the second and subsequent times, the over-pulverized particles added to the intermediate substance are preferably the step S14 of the production of the previous thermal spray material (for example, the first thermal spray material in the production of the second thermal spray material). All overmilled particles obtained in step S14) in the production of The ratio of the excessively pulverized particles to the intermediate substance after the addition of the excessively pulverized particles is, for example, about 30% by weight or less, and in the present embodiment, approximately 20% by weight.

  Subsequently, the intermediate substance obtained by adding the fine particles and the excessively pulverized particles to the liquid resin is stirred for a predetermined unit stirring time (step S124). The unit stirring time in step S124 may be the same as or different from the unit stirring time in step S121 described above. The stirring of the intermediate substance in step S124 is performed by, for example, the same stirring / defoaming apparatus as in step S121.

  When step S124 is completed, the intermediate substance is cooled (step S125). The cooling of the intermediate substance in step S125 is performed, for example, in the same manner as in step S122, using a refrigerant (such as running water or ice) lower than room temperature until the temperature of the intermediate substance reaches a predetermined stirring restart temperature. The cooling of the intermediate substance in step S125 may be performed, for example, for a predetermined cooling time. The stirring restart temperature and cooling time in step S125 may be the same as or different from the stirring restart temperature and cooling time in step S122, respectively.

  In the second and subsequent thermal spray material production, the total stirring time of the intermediate substance in step S124 is compared with the required stirring time, and steps S124 and S125 are repeated until the total stirring time is equal to or longer than the required stirring time (step S126). . The total stirring time in step S124 and the required stirring time in step S126 may be the same as or different from the total stirring time in step S121 and the required stirring time in step S123, respectively.

  As shown in FIG. 2, the nano-slurry that is the mixture generated in step S12 (that is, steps S121 to S126) becomes a cured product by curing the room temperature curable resin over time (step S13). In the cured product, fine particles and over-pulverized particles are in a monodispersed state. FIG. 8 is a cross-sectional view of the cured product observed with a scanning electron microscope. FIG. 9 is a cross-sectional view of a cured product (that is, a cured product that does not include excessively pulverized particles) generated in the first thermal spray material production, as in FIG. A portion darker than the surroundings in FIG. 8 is over-pulverized particles. From FIG. 8, it can be confirmed that in the cured product produced in the second and subsequent thermal spray material production, the over-pulverized particles are in a monodispersed state dispersed independently without contacting each other. it can.

  10 and 11 are enlarged views of parts of FIGS. 8 and 9, respectively. FIG. 10 shows a region including a part of one over-pulverized particle. A solid line 71 in FIG. 10 indicates a boundary between the over-pulverized particles and the surrounding portion, and a lower left portion of the solid line 71 corresponds to the over-pulverized particles. From FIG. 10, it can be seen that the fine particles contained in the over-pulverized particles and the fine particles located in the surrounding region other than the over-pulverized particles are evenly dispersed in the same manner. 10 and 11, it can be seen that when the excessively pulverized particles are added to the liquid resin, the fine particles are uniformly dispersed in the same manner as when the excessively pulverized particles are not added.

  The cured product obtained in step S13 is pulverized using, for example, a manual crusher or a vibration mill. The cured product after pulverization is fractionated using a sieve. Thereby, the thermal spray material whose particle size is a target particle size range (for example, 45 micrometers or more and less than 106 micrometers) is obtained (step S14).

  In the production of the thermal spray material for the second time and thereafter, the weight ratio of the thermal spray material obtained in step S14 to the cured product obtained in step S13 (that is, the cured product including over-pulverized particles) and the over-pulverized particles is over-pulverized. This is approximately the same as the weight ratio of the thermal spray material obtained in Step S14 and the over-pulverized particles from the cured product containing no particles. Specifically, the thermal spray material when the cured product does not contain over-pulverized particles and the weight ratio of the over-pulverized particles are about 64% and about 29%, whereas the thermal spray when the cured product contains over-ground particles. The weight percentage of material and overmilled particles is about 67% and about 27%. Therefore, it can be seen that when the cured product containing over-pulverized particles is pulverized in step S14, a phenomenon such that the over-pulverized particles are not properly pulverized due to separation from the cured product or the like hardly occurs.

  The thermal spray material obtained by the second and subsequent manufacturing is also used for thermal spraying in the thermal spraying apparatus 1 as in the case of FIG. That is, the thermal spray material manufactured with the manufacturing method of step S11-S14 is prepared (step S21), and the said thermal spray material is filled into the material storage part 13. FIG. (Step S22). Thereafter, plasma spraying is performed using the thermal spray material. Thereby, the heated fine particles are bonded on the base material 9, and a film is formed on the base material 9 (step S23). Thereby, thermal spraying can be easily performed using fine particles at the nanoparticle level, which has been difficult to handle in the past, while using a thermal spraying apparatus having the same structure as the conventional one. As a result, an increase in cost required for thermal spraying can be suppressed, and a decrease in efficiency of thermal spraying work can be prevented. Furthermore, it is also possible to use, as industrial materials, materials that have dramatically improved physical and chemical properties such as nanocomposite materials and nanoporous materials that take advantage of nanoparticles.

  As described above, in the second and subsequent thermal spray material production, in step S12, in addition to dispersing the fine particles in the liquid resin, over-pulverized particles obtained at the time of pulverization of the cured product in step S14 that has already been performed. Is added and dispersed in the liquid resin. Thus, the yield of the thermal spray material manufactured from the fine particles and the resin is improved by reusing small over-pulverized particles to be used as the thermal spray material in the thermal spray apparatus 1 in the subsequent production of the thermal spray material. Can do.

  In the production of thermal spray materials that do not reuse over-pulverized particles, the cured product excluding over-pulverized particles and lost particles (that is, those in which the pulverized particles are lost by air-conditioning in the manufacturing room) is sprayed. Used as a material. On the other hand, in the production of the thermal spray material that reuses the above-mentioned excessively pulverized particles, the cured product excluding the lost particles is used as the thermal spray material. Therefore, when the weight ratio of the lost particles is about 5%, The yield of the thermal spray material after repeating the production of the material a plurality of times is greatly improved to about 95%.

  By the way, as another method for reusing the excessively pulverized particles in the production of the thermal spray material, for example, the fine particles contained in the excessively pulverized particles (in this embodiment, zirconia nanoparticles) are recovered and liquidized in step S121. It can be considered to reuse as fine particles to be mixed with the resin. In this case, a process such as heating the excessively pulverized particles or dissolving them in a solvent is required, so that a great deal of labor is required for collecting the fine particles. In addition, it is difficult to prevent foreign matter from adhering to and mixing with the fine particles in the recovery process. As yet another method of reusing the over-pulverized particles, for example, it is conceivable to collect the over-pulverized particles and granulate them into particles in the target particle size range, but it is necessary to dissolve the over-pulverized particles during granulation, Re-curing of the resin after dissolution is technically difficult.

  On the other hand, in the production of the above-mentioned sprayed material, since the fine particles and the excessively pulverized particles are dispersed in the liquid resin in step S12 and reused, the process of heating or dissolving the excessively pulverized particles is not required, and the excessively pulverized particles are eliminated. Can be easily reused. In addition, in the process of reusing the excessively pulverized particles, it is possible to prevent foreign matters from adhering to and mixing with the fine particles in the excessively pulverized particles. Furthermore, since the ratio of the fine particles to the resin in the over-pulverized particles is substantially the same as the ratio of the fine particles to the liquid resin in Step S121, the hardening obtained in the second and subsequent productions that reuse the over-pulverized particles. The ratio of the fine particles in the material and the sprayed material is substantially equal to the ratio of the fine particles in the cured product and the sprayed material obtained in the first production without reusing the excessively pulverized particles. For this reason, even if it is a case where the spraying material manufactured at any time is used, a uniform film can be formed on the base material 9 by the thermal spraying by the thermal spraying apparatus 1.

  As described above, in the production of the thermal spray material for the second and subsequent times, in step S12, the addition of the excessively pulverized particles to the liquid resin (step S124) is performed after the dispersion of the fine particles in the liquid resin (step S121). Done. This prevents over-pulverized particles from affecting the dispersion of fine particles in the resin. In addition, since the fine particles are dispersed in a monodispersed state in the resin when the over-pulverized particles are added, the influence of the fine particles on the dispersion of the over-pulverized particles in the resin can be suppressed. As a result, both the fine particles and the excessively pulverized particles can be easily and uniformly dispersed in the liquid resin.

  As described above, the pulverization time of the cured product in step S144 is determined in advance based on the ratio of the thermal spray material and the excessively pulverized particles obtained in step S14. As a result, the amount of the thermal spray material obtained in one step S144 can be increased to improve the efficiency of the manufacturing work, and the amount of over-pulverized particles generated in one step S144 can be suppressed. The yield of the thermal spray material obtained in step S14 can also be improved efficiently.

  In the second and subsequent manufacturing of the thermal spray material, the over-pulverized particles added to the liquid resin in step S12 are in a state of being separated from the thermal spray material and aggregated by the sieve in step S14. For this reason, handling of the excessively pulverized particles can be facilitated when recovering the excessively pulverized particles or adding them to the liquid resin. Moreover, it is suppressed that the excessively pulverized particles obtained in step S14 are scattered and lost due to air conditioning or the like. As a result, the yield of the thermal spray material can be further improved.

  As described above, the over-pulverized particles added to the liquid resin in step S12 are all the over-pulverized particles obtained in the immediately preceding step S14. As a result, it is not necessary to store and use the excessively pulverized particles generated in the production of one thermal spray material over the subsequent multiple productions of the thermal spray material, thereby simplifying the production of the thermal spray material. In addition, the thermal spray material can be efficiently manufactured.

  Also in the production of the thermal spray material for the second time and thereafter, in the same manner as in the production of the thermal spray material for the first time, in step S12, the intermediate substance in which the fine particles are added to the liquid resin having room temperature curing properties is determined by predetermined unit stirring. After stirring for the time, the intermediate substance is cooled (steps S121 and S122). Then, steps S121 and S122 are repeated until the total stirring time of the intermediate substance is equal to or longer than the required stirring time (step S123). Thereby, it can suppress that a liquid room temperature curable resin hardens | cures before dispersion | distribution of microparticles | fine-particles, and can manufacture easily the thermal spray material which the microparticles | fine-particles disperse | distributed in the monodispersed state in the room temperature curable resin. In addition, when a liquid resin having room temperature curing properties is used, the intermediate material is heated or irradiated with light when the intermediate material in which the fine particles are dispersed in a monodispersed state is cured. Since it is not necessary, the thermal spray material can be manufactured more easily.

  Furthermore, in the production of the thermal spray material for the second time and thereafter, in step S12, after the intermediate substance obtained by adding the fine particles and the excessively pulverized particles to the liquid resin having room temperature curing property is stirred for a predetermined unit stirring time. The intermediate substance is cooled (steps S124 and S125). Then, steps S124 and S125 are repeated until the total stirring time of the intermediate substance is equal to or longer than the necessary stirring time (step S126). As a result, the liquid room temperature curable resin can be prevented from curing before the dispersion of the overground particles, and the thermal spray material in which the overground particles are dispersed in the room temperature curable resin in a monodispersed state can be easily manufactured. it can.

  FIG. 12 is a view showing another example of the thermal spraying apparatus 1a. The thermal spraying device 1 a has two material storage parts 13 and two quantitative supply parts 31. The conveyance pipes 32 extending from the two fixed quantity supply units 31 merge on the way. Different thermal spray materials are respectively stored in the two material reservoirs 13. That is, the two types of thermal spray materials differ in the material of the fine particles contained in the resin particles. Each of the two types of thermal spray materials is manufactured by the above-described thermal spray material manufacturing method. In the production of the two types of thermal spray materials, preferably, the recycle of over-pulverized particles is performed (steps S124 to S126). Which of the material reservoirs 13 is supplied with the thermal spray material to the thermal spray gun 11 is determined by the control of the two valves 34 provided on the transfer pipe 32 and the air supply unit 14. The other structure of the thermal spraying apparatus 1a is the same as that of the thermal spraying apparatus 1 of FIG. 1, and the same code | symbol is attached | subjected to the same component.

  FIG. 13 is a diagram showing a flow of work when performing thermal spraying with the thermal spraying apparatus 1a of FIG. When two types of thermal spray materials are prepared by the above manufacturing method (step S31), these are filled in the two material reservoirs 13 (step S32). Then, by performing spraying using one of the spraying materials, fine particles are bonded onto the base material 9 to form a coating (step S33). Next, by performing thermal spraying using the other thermal spray material, another type of other fine particles are combined on the existing coating formed in step S33 to form another coating (step S34). .

  In this way, by changing the material of the fine particles contained in the thermal spray material, it is possible to easily change the thermal spray material only by switching the supply path. In the thermal spraying apparatus 1a, three or more material reservoirs 13 may be provided, and three or more coating layers may be laminated with three or more types of thermal spray materials. Two or more kinds of coatings may be repeatedly laminated. That is, in the thermal spraying apparatus 1a, a plurality of types of coatings can be easily laminated on the substrate 9.

  Various modifications can be made in the above-described thermal spray material manufacturing and thermal spraying apparatuses 1 and 1a.

  Stirring of the intermediate substance in steps S121 and S124 may be performed by various apparatuses, or may be manually performed by an operator using a stirring bar or the like. The unit stirring time may be appropriately changed within a range in which the curing of the room temperature curable resin in the intermediate substance does not proceed excessively. The cooling of the intermediate substance in steps S122 and S125 may be performed by various methods. For example, the intermediate substance may be cooled by injecting a gas at normal temperature or lower than normal temperature toward the intermediate substance. Further, the cooling of the intermediate substance may be performed by leaving the intermediate substance in a normal temperature atmosphere. The temperature at which the stirring is resumed and the cooling time may be appropriately changed as long as the normal temperature curable resin in the intermediate material does not excessively cure.

  In the production of the thermal spray material for the second and subsequent times, the over-pulverized particles added to the liquid resin in step S124 are not necessarily all over-pulverized particles obtained in the production of the immediately preceding thermal spray material. It may be a part of over-pulverized particles. Further, the excessively pulverized particles added to the liquid resin may be the excessively pulverized particles obtained in the production of the thermal spray material a plurality of times before. Furthermore, in step S124, the excessively pulverized particles in an aggregated state may be crushed and then added to the liquid resin.

  In the second and subsequent thermal spray material production, steps S124 to S126 (dispersion of excessively pulverized particles) may be performed in parallel with steps S121 to S123 (dispersion of fine particles) in step S12. In this case, first, fine particles and over-pulverized particles are mixed almost simultaneously with the liquid resin, and the intermediate substance, which is a liquid resin containing fine particles and over-pulverized particles, is stirred for a unit stirring time. Subsequently, the intermediate substance is cooled until the temperature of the intermediate substance reaches the stirring resumption temperature or for a predetermined cooling time. Then, the stirring and cooling of the intermediate substance are repeated until the total stirring time of the intermediate substance reaches or exceeds the required stirring time. Alternatively, steps S124 to S126 may be performed before steps S121 to S123. In either case, the yield of the thermal spray material can be improved by reusing the excessively pulverized particles to produce the thermal spray material.

  In the above manufacturing method, after the liquid resin is generated by mixing and stirring the main component of the room temperature curable resin and the curing agent, the fine particles are added to the liquid resin. , And may be performed in parallel with the mixing of the main agent and the curing agent. In the production of the thermal spray material for the second and subsequent times, addition of fine particles and excessively pulverized particles may be performed in parallel with mixing of the main agent and the curing agent.

  As described above, even when the production of the thermal spray material is repeated a plurality of times, in the production of the thermal spray material for the second and subsequent times, it is not always necessary to reuse the over-pulverized particles and add them to the liquid resin.

  The thermal spraying in the above embodiment can be used for manufacturing various thermal sprayed products in which a coating is formed on a substrate. Furthermore, it is also possible to use only the coating portion as a product. When the nanoporous structure is formed by keeping the bonding of fine particles due to thermal spraying to sintering, thermal spraying is used to manufacture catalyst carriers, various battery electrodes, additives, filters, functional inks, semiconductor devices, thermal barrier coatings, thermal insulation covers, etc. Can be used. When a dense structure is formed by melting and bonding particles, spraying can be used, for example, in the production of anticorrosion coatings, machined parts (such as cutters), and heat resistant parts (such as crucibles and boiler tubes). .

  The thermal spraying apparatuses 1 and 1a may be apparatuses that perform flame spraying or laser spraying, and the thermal spray gun 11 may be another type of thermal spray gun. In other words, the thermal spray material manufactured by the above-described manufacturing method may be used for flame spraying or laser spraying. By performing flame spraying or laser spraying using the thermal spray material, the heated fine particles are bonded on the substrate to form a coating. In any of the thermal spraying methods, so-called nanoparticles can be easily used for thermal spraying with little or no modification of existing apparatuses.

  The configurations in the above-described embodiments and modifications may be combined as appropriate as long as they do not contradict each other.

1,1a Thermal spraying device 9 Base material S11-S14, S21-S23, S31-S34, S121-S126, S141-S145 Step

Claims (9)

A method for producing a thermal spray material used for plasma spraying, flame spraying or laser spraying,
a) a step of dispersing ceramic or metal fine particles in a liquid resin having room temperature curability;
b) crushing the cured product obtained by curing the mixture obtained in the step a) to obtain a thermal spray material which is a particle having a particle size larger than the fine particles;
With
Step a)
a1) stirring the intermediate substance obtained by adding the fine particles to the liquid resin for a predetermined unit stirring time;
a2) cooling the intermediate substance after the a1) step;
a3) repeating the steps a1) and a2) until the total stirring time of the intermediate material is equal to or longer than the required stirring time;
A method for producing a thermal spray material, comprising: It is a manufacturing method of the thermal spray material of Claim 1,
In the step a2), the intermediate material is cooled by a refrigerant having a temperature lower than normal temperature. It is a manufacturing method of the thermal spray material according to claim 1 or 2,
In the step a2), the intermediate material is cooled until the temperature of the intermediate material is equal to or lower than the stirring resumption temperature. A method for producing a thermal spray material according to any one of claims 1 to 3,
A method for producing a thermal spray material, wherein an average particle size of the fine particles is 25 nm or more and 1000 nm or less by a laser diffraction / scattering method or a dynamic light scattering method. A method for producing a thermal spray material according to any one of claims 1 to 4,
A method for producing a thermal spray material, further comprising the step of generating the liquid resin by mixing and stirring the main agent and the curing agent before the step a).   A thermal spray material used for plasma spraying, flame spraying, or laser spraying, which is manufactured by the manufacturing method according to claim 1. A thermal spraying method,
d) preparing a thermal spray material manufactured by the manufacturing method according to any one of claims 1 to 5;
e) forming a film by bonding the heated fine particles on a substrate by performing plasma spraying, flame spraying or laser spraying using the thermal spray material;
A thermal spraying method comprising: The thermal spraying method according to claim 7,
f) a step of preparing another thermal spray material that is manufactured by the manufacturing method according to any one of claims 1 to 5 and includes other fine particles formed of a material different from the fine particles;
g) After the step e), by performing plasma spraying, flame spraying, or laser spraying using the other spraying material, the other fine particles are deposited on the coating formed in the step e). Forming another film by bonding; and
The thermal spraying method further comprising:   A thermal spray product in which a coating is formed on a substrate by the thermal spraying method according to claim 7 or 8.