JP2019512611A - High flowability thermal spray powder and method for producing the same - Google Patents

Abstract

Disclosed is a high flowability powder to be introduced into a thermal spray gun, and a coating method using the same, in which the flow characteristics are improved in order to improve the quality of the thermal spray coating film. The flow characteristics of the thermal spray powder can be greatly improved by coating the surface of the thermal spray powder in the form of granules, the thermally treated thermal spray powder, or the plasma surface treated thermal spray powder with an organic monomer. Also, the improved flow characteristics of the organic monomer coated thermal spray powder allow for increased coating yield, improved coating layer quality, and extended duration of use of the spray gun. The price competitiveness of the thermal spray powder can be enhanced. [Selected figure] Figure 8

Description

  The present invention relates to a high fluidity spray powder and a method of manufacturing the same. More particularly, the present invention relates to a high flow spray powder in which the surface of the powder is coated with an organic monomer, and a method of producing the same.

  Ceramic thermal spray coating technology using thermal spray powder is applied to various fields, and by industry, it is most actively applied to general machinery, semiconductors, liquid crystals, steel, and printing fields. The thermal spray coating technology is a very promising technology in which the market size of China, Korea, Singapore, etc. is expanding, and the market size of Asia as a whole has grown to the same extent as the United States and the EU.

  Thermal spray coating methods using thermal spray powder include arc thermal spray method, flame spray method, high speed flame spray method, plasma spray method, cold spray (CS) method, SPS method (suspension plasma spray), SPPS method Solution precursor plasma spray) and the like.

From the aspect of thermal spray materials, active development and sales are being made for stabilized zirconia (YSZ) used for thermal barrier coatings, Al ₂ O ₃ as an insulating material, and TiO ₂ for photocatalysts, In Japan, hydroxyabatite, which is a biomedical material, is also being developed to be applied to thermal spray coating materials with high added value. Tungsten (W) is also an important material as a high temperature material for shielding of radiation and plasma partition of nuclear fusion reactor in the field of nuclear power, and thermal spray coatings have been developed for this application.

  Ceramic spray coating technology is widely used for the coating of wear resistant materials to improve wear resistance, and the wear resistant coating by thermal spray coating has sufficient mechanical strength. The thermal spray coating is able to withstand contact with the opposing structural surface that comes into contact in the form of sliding, rolling, or impact, and also allows control over friction and wear. Ceramic powder materials are used at a considerable level as thermal spray coating materials. The ability to effectively control wear and friction through such ceramic coatings has continually expanded the applications in the industrial field.

  In the thermal spray coating method, it is the maintenance of the discharge speed of the thermal spray powder discharged from the thermal spray powder supply unit that has the greatest influence on the quality of the thermal spray coated film. When the spray speed of the thermal spray powder is not kept constant during thermal spray coating, the uniformity of the thermal spray coating film decreases, the generation rate of pores deviates from the design value, and the strength of the thermal spray coating decreases. Indicated.

  In addition, in the thermal spray powder supply unit of the thermal spray gun, when the thermal spray powder is discharged from the nozzle to the plasma or flame of the thermal spray gun, a clogging phenomenon occurs. Like the phenomenon that occurs with an hourglass, it is a frequent problem when powder is discharged from a limited inlet.

  When a slurry is prepared from the powder used for thermal spray coating and the slurry is discharged and used, the clogging phenomenon is suppressed and the discharge amount can be maintained by a constant pressure.

  However, in the discharge using the slurry, the quality of the sprayed coating is degraded by the organic impurities contained in the preparation of the slurry.

  In addition, the thermal spray powder prepared by the spray drying method has the quality of the thermal spray coating reduced depending on the shape of the granules, the surface roughness of the granules, and the like.

  Many of the thermal spray powders currently applied are applied to the thermal spray coating by reducing the friction between the powders by spheroidizing in the spray drying method and reducing the clogging phenomenon by controlling the center of gravity of the powder to the spherical center. ing.

  However, there is a problem that the cost is high for preparing the powder by aligning its center of gravity to the spherical center, and the preparation is difficult.

  In addition, the low flow property value of the powder leads to degradation of the thermal spray coating.

According to Korean Patent No. 10-0669819 (filing date: August 19, 2003), powder is dispersed using a non-aqueous solvent at the time of preparation of the slurry, and the slurry _A technology is described that prepares powder powders of ₂ O ₃ system, Al ₂ O ₃ system, TiO ₂ system, AIN system, nitride system, and then sinter heat treatment of the granule powder to complete preparation of ceramic powder . In particular, the flowability of the conventional Y ₂ O ₃ raw material powder is in a state where measurement is impossible, and when the powder is prepared by spray drying, it is reported to have a flowability of 0.19 g / s.

  However, there are limits to improving the flow characteristics of the powder through changes in powder preparation and still have not been able to significantly improve the quality of the thermally sprayed coating.

  In Korean Patent No. 10-0863697 (filing date: December 31, 2007), powder for thermal spray coating and organic substance for sealing are used to seal the thermal spray coating without additional process. Techniques have been described for co-spraying with the powder to form a sprayed coating.

  In addition, the powder for thermal spray coating is formed by surrounding a sealing film on the outer surface of the ceramic powder, and the organic powder for sealing is obtained by heat treatment in a state of surrounding the outer surface. The particle size ratio of the ceramic powder to the organic powder is 1: 0.1 to 0.3, and the range is further narrowed, so that the content ratio of the ceramic powder to the organic powder is 1: 0.2 to 0. The thermal spraying powder adjusted to 5 is proposed.

  However, the prior art is for forming a sealing film of the thermal spray coating at the time of formation of the thermal spray coating, and since a considerable amount of organic matter is coated on the ceramic powder, the thermal spraying is caused by the occurrence of aggregation between the thermal spray powders. There is a problem that the quality such as the uniformity of the coating film is reduced.

  In addition, there is also a problem that the quality of the thermal spray coating is deteriorated due to the delay of the discharge of the powder due to the clogging phenomenon generated at the time of the discharge of the thermal spray powder.

Specification of Korean Patent No. 10-0669819 Specification of Korean Patent No. 10-0863697

  The first technical problem to be achieved by the present invention is to provide a high flowability thermal spray powder having improved flow characteristics when the powder is discharged.

  In addition, a second technical problem to be achieved by the present invention is to provide a method for producing a high flowability thermal spray powder for achieving the first technical problem.

  The present invention for achieving the first technical object mentioned above provides a high flowability thermal spray powder characterized by comprising a granular powder and an organic monomer attached to the surface of the granular powder. .

The granule powder may include any one selected from the group consisting of ZrO ₂ , Y ₂ O ₃ , Al ₂ O ₃ , AlN, HfO ₂ , TiO ₂ , and stabilized zirconia. It is characterized by being a thermal spray powder.

  The granular powder is characterized in that it is a high flow thermal spray powder, which is a powder produced through a granulation process.

  The granular powder is characterized in that it is a high flow thermal spray powder, which is a powder surface-treated by plasma.

  It is characterized in that the granular powder surface-treated by the plasma is a high flowability thermal spray powder whose surface roughness is reduced.

  The granular powder surface-treated by the plasma is characterized in that it is a high-fluidity sprayed powder in which the surface is melted to increase the surface density.

  The granular powder is characterized in that it is a highly fluid spray powder which is stabilized zirconia.

  It is characterized in that it is a high fluidity spray powder, wherein the content of the organic monomer is in the range of 0.05 wt% to 5.0 wt% with respect to the weight of the granular powder.

  It is characterized in that the organic monomer is a high fluidity thermal spray powder which occupies 5% to 100% of the surface area of the granular powder.

  The organic monomer may include any one selected from the group consisting of an anionic surfactant, a cationic surfactant, an amphoteric surfactant, and a nonionic surfactant. It is characterized by being a high fluidity spray powder.

Examples of the organic monomer include palmitic acid, tetraethyl orthosilicate, hexamethyldisiloxane, acrylic acid, styrene, ethylene, acrylamide, methacrylic acid, acrylate, vinyl carboxylic acid, acrylonitrile acrylonitrile, propylene oxide, butyl acrylate, stearic acid (C ₁₇ H ₃₅ COOH), oleic acid, CH ₃ (CH ₂ ) ₇ CH = CH (CH ₂ ) ₇ COOH, eicosanoic acid _{(eicosanic acid, C 19 H 39} COOH), and docosane _{(Docosanoic acid, C 21 H 43} COOH) can contain one or selected from the group consisting of, characterized in that it is a highly fluid spray powder.

  According to the present invention for achieving the above-mentioned second technical object, the present invention comprises the steps of preparing a granular powder produced through a granulation process, injecting an organic monomer into a solvent to prepare an organic monomer solution, A high flowability thermal spray powder comprising the steps of: charging and mixing the granular powder in the organic monomer solution; and coating the organic monomer on the surface of the granular powder while evaporating the solvent. It provides a manufacturing method.

The granular powder is any one selected from the group consisting of ZrO ₂ , Y ₂ O ₃ , Al ₂ O ₃ , AlN, HfO ₂ , TiO ₂ , and stabilized zirconia. It is a manufacturing method of flowable thermal spray powder.

  The method according to any one of the preceding claims, further comprising plasma surface treating the granular powder after preparing the granular powder produced through the granulation process.

  It is a method of producing a high flowability thermal spray powder, characterized in that the surface of the granular powder is melted to increase its surface density and the surface roughness is reduced by the plasma surface treatment.

  It is a method for producing a high flowability thermal spray powder, wherein the granular powder is stabilized zirconia.

  According to the present invention described above, the organic coating layer is formed on the surface of the thermal spray powder, which has the effect of inducing generation of a certain amount of static electricity (repulsion) on the surface of the thermal spray powder and preventing aggregation between the powders. .

  In addition, during the thermal spray coating of the organically coated powder, the flow characteristics of the powder may be improved to suppress the clogging phenomenon of the thermal spray nozzle.

  Further, by improving the flow characteristics of the powder at the time of thermal spray coating, the uniformity of the thickness of the thermal spray coating film is improved, and there is an effect that the surface roughness is reduced.

  Also, the use of the powder with improved flow characteristics has the effect of prolonging the continuous use time of the plasma spray gun for thermal spray coating.

  In addition, the use of the powder having improved flow characteristics has the effect of eliminating the nozzle clogging phenomenon of the powder injector portion of the thermal spray gun.

5 is a flowchart illustrating a process of coating an organic monomer on the surface of a thermal spray powder according to a preferred embodiment of the present invention. It is a 300 times electron micrograph of the granule powder of 5 micrometers-25 micrometers based on one preferable Example of this invention. It is a 1000 times electron micrograph of the granule powder of 5 micrometers-25 micrometers based on one preferable Example of this invention. It is a 300 times electron micrograph of the granule powder of 15 micrometers-45 micrometers based on one preferable Example of this invention. It is a 1000 times electron micrograph of the granule powder of 5 micrometers-25 micrometers based on one preferable Example of this invention. It is a 300 times electron micrograph of the powder which carried out the plasma surface treatment of the granule powder of 15 micrometers-45 micrometers based on one preferable Example of this invention. It is a 1000 times electron micrograph of the powder which carried out the plasma surface treatment of the granule powder of 15 micrometers-45 micrometers based on one preferable Example of this invention. FIG. 2 is a schematic view of a cross section of an organic monomer-coated granular powder according to a preferred embodiment of the present invention. FIG. 1 is a schematic view of a cross section of an organic monomer coated and plasma surface treated granular powder according to a preferred embodiment of the present invention. FIG. 1 is a schematic view of an experimental apparatus for measuring the flow rate of thermal spray powder according to a preferred embodiment of the present invention. 5 is an electron micrograph of a cross section of a coating layer sprayed by using a thermal spray powder according to a preferred embodiment of the present invention. 12 is an electron micrograph of a cross section of a coating layer measured by enlarging a region of a dash circle shown in FIG. 11 according to a preferred embodiment of the present invention.

  While the invention is susceptible to various modifications and alternative forms, specific embodiments are shown by way of example in the drawings and will herein be described in detail. However, this is not intended to limit the present invention to a particular disclosed form, but is to be understood as including all modifications, equivalents and alternatives falling within the spirit and scope of the present invention. is there. In the description of each drawing, similar reference numerals are given to similar components.

  Unless defined otherwise specifically, all terms used herein, including technical and scientific terms, are identical to those commonly understood by one of ordinary skill in the art to which this invention belongs. It has the meaning of Terms as defined in a commonly used dictionary should be construed as having a meaning consistent with the meaning they have in the context of the relevant art, and are ideal unless explicitly defined in the present application. It is not or is not interpreted in an overly formal sense.

  The present invention will now be described more fully with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown.

  FIG. 1 is a flow chart showing a process of coating an organic monomer on the surface of a thermal spray powder (granular powder) according to a preferred embodiment of the present invention.

  Referring to FIG. 1, the thermal spray powder is manufactured by a spray drying method which is a conventional method. The powder produced by the spray drying method is a powder in the form of granules, and is a powder in the form of an aggregate of fine powders.

  Granular powder is usually calcined or fired and used as a thermal spray powder. The calcination step is performed at 1200 ° C. for 4 hours or less, and the firing step is subsequently performed at 1600 ° C. for 4 hours or less to adopt the heat treatment step according to the required characteristics of the thermal spray powder. Such a process can be carried out to prepare a thermal spray powder.

  In the present invention, after the granular powder is prepared through the calcination step or the calcination step, the granular powder is put into a solution in which the organic monomer is melted. After the granular powder is charged, the solution is stirred and the granular powder is well dispersed in the solution.

  After the granular powder is well dispersed in the solution, the solution is heated to evaporate the solvent. Subsequently, the surface of the granular powder is coated with an organic monomer. When the evaporation rate of the solvent is low, the solution is heated in a water bath mode so that the entire solution is uniformly heated. The evaporation rate of the solvent varies depending on the amount of the whole solution, but is adjusted by optimizing the process.

  When all the solvent evaporates, the thermal spray powder appears to be in a state of aggregation. This aggregation state can be eliminated through a sieving process or a simple crushing process.

  The amount of organic monomer coating on the surface of the granular powder can be adjusted according to the amount of the organic monomer charged at the time of preparation of the initial solution or the amount of granular powder introduced into the solution.

  When proceeding with the thermal spray coating process using granular powder, discharge of granular powder does not occur. Therefore, the granular powder is subjected to a calcination process or a calcination process to increase the density of the powder, to reduce the surface roughness, and used as a thermal spray powder applicable to the thermal spraying process. However, for thermal spray coating, there is a problem in the discharge of powder, which greatly affects the quality of the thermal spray coated film. We have the know-how of powder processing by thermal spray coating companies, and we have specified the specifications of thermal spray powder for thermal spray coating, but problems like powder discharge delay at the time of thermal spray coating are always present .

  FIG. 2 is a 300 × electron micrograph of granule powder in the 5 μm to 25 μm range according to a preferred embodiment of the present invention.

  Referring to FIG. 2, it is an electron micrograph of the granule powder produced by the spray drying method, wherein the particle size distribution is in the range of 5 μm to 25 μm.

  FIG. 3 is a 1000 × electron micrograph of granular powder in the 5 μm to 25 μm range according to a preferred embodiment of the present invention.

  Referring to FIG. 3, it is indirectly predicted that the surface roughness of the granular powder is a large value from the surface state of the granular powder. Granular powder was prepared by subjecting the fine powder to calcination and calcination steps.

  In addition, the electron micrograph shows that a considerable amount of internal pores are present, and accordingly, the surface area of the powder is large, so it can be expected that the amount of static electricity generated due to the friction between the powders is large. The excessive charge amount on the surface of the granular powder generates positive charge, and the frequency of contact between the powders increases in a certain space, so that the granular powder is easily aggregated.

  For this reason, when the granular powder produced by the spray drying method is introduced by a spray gun for thermal spray coating, the agglomerated powder easily generates a clog phenomenon. Therefore, since the discharge of the granular powder is not normally performed to the limited discharge hole, the normal thermal spray coating can not be performed.

  Usually, the surface condition of the powder is changed by the firing process of the granular powder, or the powder whose powder distribution is optimized is used to be compatible with the thermal spray coating, but the quality and coating efficiency of the thermal spray coating Does not improve.

  FIG. 4 is a 300 × electron micrograph of granular powder in the range of 15 μm to 45 μm according to a preferred embodiment of the present invention.

  Referring to FIG. 4, it is an electron micrograph of granule powder produced by the spray drying method, wherein the particle size distribution is in the range of 15 μm to 45 μm.

  FIG. 5 is a 1000 × electron micrograph of granule powder in the range of 15 μm to 45 μm according to a preferred embodiment of the present invention.

  Referring to FIG. 5, although the size distribution of the granular powder is upward to the right, the surface roughness of the granular powder is not reduced, and it can be seen that pores are present inside the granular powder.

  As the size distribution of the granular powder is increased and the thermal spray coating proceeds, almost no discharge of the granular powder occurs. That is, even when the size distribution of the thermal spray powder is directed upward, the state of the charge generated on the surface of the powder is generated in the tendency of the powder to coagulate.

  FIG. 6 is a 300 × electron micrograph of plasma surface-treated powder in the range of 15 μm to 45 μm according to a preferred embodiment of the present invention.

  Referring to FIG. 6, it is an electron micrograph of a powder obtained by plasma surface treating granular powder produced by a spray drying method, which is a plasma surface treated thermal spraying powder having a size distribution in the range of 15 μm to 45 μm.

  FIG. 7 is a 1000 × electron micrograph of plasma surface-treated powder in the range of 15 μm to 45 μm according to a preferred embodiment of the present invention.

  Referring to FIG. 7, it can be predicted that the surface of the plasma surface-treated granular powder is very smooth and the surface density is improved, and almost no pores are seen in the photograph.

  FIG. 8 is a schematic view of a cross section of an organic monomer-coated granular powder according to a preferred embodiment of the present invention.

  FIG. 9 is a schematic view of a cross section of an organic monomer coated and plasma surface treated granular powder according to a preferred embodiment of the present invention.

  Referring to FIGS. 8-9, this structure is a form in which the surfactant is adsorbed to the surface of the granular powder in a micellar structure. The micelle structure is a structure of an organic monomer adsorbed on the surface of the powder, wherein the portion bound to the surface of the powder is a hydrophobic portion and the portion in contact with air is a hydrophilic portion . When water is used as a solvent to dissolve the organic monomer and the thermal spray powder (granular powder) is charged, the organic monomer adheres to the surface of the thermal spray powder (granular powder). At this time, a portion of the organic monomer in contact with water is negatively charged, a hydrophobic substance such as oil is in contact with the surface of the powder, and the organic monomer has a micelle structure. Form

  When the granular powder is introduced into the solution in which the organic monomer is dissolved, the organic monomer is bound to the surface of the granular powder. When the solvent is water, the organic monomer of the lipophilic part is attached to the surface of the granular powder, and the hydrophilic part is located on the solvent side. When this happens, the granular powder will be present in a dispersed state in the solvent.

  The thermal spray powder (granular powder) is dispersed in a solution containing the organic monomer, and the solvent is slowly evaporated to obtain a thermal spray powder (granular powder) coated with the organic monomer.

  Although the surface of the granular powder coated with the organic monomer is not largely reduced in surface roughness, the film formed of the organic monomer reduces the generation of friction between the granular powder and the organic monomer The cohesion between the granular powder is controlled by the appropriate amount of static electricity generated in the film formed in the above.

  Also in the case of plasma-surface-treated granular powder, when a film is formed with an organic monomer, aggregation between the powders is controlled by reducing the occurrence of frictional force between the granular powder.

  FIG. 10 is a schematic view of an experimental apparatus for measuring the flow rate of the thermal spray powder according to a preferred embodiment of the present invention.

  Referring to FIG. 10, it is a schematic view of a powder flow rate measuring apparatus, which comprises a sample cup 70 including a measurement funnel 100 into which powder is loaded, and a specific gravity cup 60 in which a free-falling powder enters. The sample cup 70 and the specific gravity cup 60 are separated such that the distance 80 between the cups is 48 mm, and the internal volume of the specific gravity cup 60 is about 100 cc.

  The standard measurement method for the evaluation of the flow characteristics is defined in KS L 1618-4. This standard is the result of the “Abrasives and Special Ceramics Products KS Standardization Research” task, which is part of the Standardized Academic Research Service business implemented at the Technical Standards Institute in 2002.

  Powders of ceramic material are mostly granulated due to handling problems, and are manufactured by spray drying granulation method, etc., and the characteristics such as granule diameter, bulk density, loss on drying, fluidity are standard. Confirm by the method.

  Since the range of the diameter of the granular powder of the ceramic material is approximately 20 μm to 500 μm, most ceramic granules are included in this diameter range by limiting the range to several tens to several hundreds of micrometers. Be

  The measurement order of the powder flow rate is as follows. After the measurement sample which is the thermal spray powder is filled in the measurement funnel 100, the filled sample is freely dropped into the specific gravity cup 60 through the discharge port 90 of the powder. The free fall time of the powder is measured a total of three times and the average value is determined.

  The fluidity F is calculated to three decimal places by the following equation, and after three measurements, the measurement results of three times are calculated by arithmetic averaging.

Here, F is the fluidity (g / s), w ₁ is the mass of the specific gravity cup 60 (g), w ₂ is the total mass (g) of the specific gravity cup 60 and the sample freely dropped to the specific gravity cup 60, t is It is the time (s (seconds)) required for the sample to free fall. That is, w ₂ -w ₁ is the mass of the sample freely dropped to the specific gravity cup 60.

Example 1
The solution is prepared using palmitic acid as the organic monomer material. 0.2 g of palmitic acid is prepared, placed in a beaker containing 200 ml of ethanol, and sufficiently stirred and dissolved for about 0.5 hours. Care is taken not to excessively reduce the amount of ethanol in the process of dissolving palmitic acid.

  Into the ethanol solution in which palmitic acid is dissolved, 10 g of the stabilized zirconia granule powder is charged while being continuously stirred until the total granule powder amount reaches 100 g. A granular powder having a size of 5 μm to 25 μm was used to advance palmitic acid coating. Stirring was continued until the granular powder was dispersed in the solution for a sufficient time of 1 hour or more.

  Subsequently, ethanol used as a solvent was evaporated while advancing stirring and heating of a solution containing granular powder, so that only palmitic acid-coated granular powder (palmitic acid-coated granular powder) was left. The palmitic acid-coated granular powder, which remained in a weakly agglomerated state, was broken down using a sieving process.

The size distribution of the powder prepared by the method described above was almost the same as the size distribution of the granular powder initially loaded. The content (by weight) of palmitic acid (CH ₃ (CH ₂ ) ₁₄ COOH) is 0.2 wt% relative to the granular powder, so the granular powder size hardly increases.

  The flow characteristics of the prepared palmitic acid coated granular powder were measured as described above. In the case of the stabilized zirconia granular powder before coating with palmitic acid, the flow characteristics are in a very low state, and it can be said that the measured value is almost zero level. On the contrary, the palmitic acid-coated granular powder had a remarkably improved flowability, and the flowability was 1.0912 g / s.

  The electron micrographs of palmitic acid-coated granular powder are similar to the photographs of FIGS. Since the coating film thickness by 0.2 wt% of palmitic acid is a very small value, observation by electron micrograph is difficult.

  The surface roughness is measured by scanning the surface of the granular powder microscopically using AFM, and it is 20 nm or more. On the other hand, the surface roughness of palmitic acid-coated granular powder is measured to be less than 20 nm. From these results, the coating of palmitic acid on the surface of granular powder can be confirmed indirectly.

  The coating amount of palmitic acid is preferably 0.01 wt% to 5.0 wt% with respect to granular powder, but is not limited thereto.

Comparative Example 1
0.2 g of polystyrene (polystylene), which is a polymer, is prepared, placed in a 200 ml beaker containing ethanol, and dissolved by sufficiently stirring for about 0.5 hours.

  As in Example 1, a polystyrene coating was developed on 100 g of the stabilized zirconia granule powder. The flow characteristics were measured on the prepared polystyrene-coated stabilized zirconia granule powder (polystyrene-coated granule powder). The fluidity of the polystyrene-coated granular powder was 0.4453 g / s.

  As described above, the prepared thermal spray powder was loaded to a plasma gun, and the thermal spray powder was discharged to produce a thermal spray coating film. The thermal spray coated film produced was not uniform in the surface, and a sharply projecting portion was also observed. It is presumed that this is because when the thermal spray powder is discharged, the quality of the thermal spray coating is degraded due to the clogging phenomenon or the partial condensation phenomenon of the thermal spray powder. In order to improve the quality of the thermal spray coating, it is necessary to improve the flow characteristics of the thermal spray powder.

  In addition, when a thermal spray coating is manufactured using polymer-coated granular powder, the quality of the thermal spray coating is degraded because the amount of residual carbon in the thermal spray coating is increased.

Comparative Example 2
Prepare 0.2 g of glycolic acid which is an oligomer (trimer) in which a small number of monomers are polymerized, add 200 ml of ethanol to a beaker, and stir sufficiently for about 0.5 hours. Let it dissolve.

  As in Example 1, a glycolic acid coating was developed on 100 g of the stabilized zirconia granule powder. The flow characteristics were measured on the stabilized zirconia powder powder (glycolic acid-coated powder powder) coated with glycolic acid which is a trimer. The flow rate of the glycolic acid-coated granular powder was 0.6521 g / s.

  Compared to polystyrene coated granular powders, the flow properties were improved to a low level and as a thermal spray powder applied to a thermal spray coating, the result was not very bad.

Example 2
0.2 g of palmitic acid is prepared, placed in a 200 ml beaker containing ethanol, and dissolved by sufficiently stirring for about 0.5 hours. Care is taken to maintain the amount of ethanol in the process of dissolving palmitic acid.

  Into the ethanol solution in which palmitic acid is dissolved, 10 g of the stabilized zirconia granule powder is charged while being continuously stirred until the total granule powder amount reaches 100 g. A granular powder in the range of 15 μm to 45 μm in size was used to proceed with palmitic acid coating. Stirring was continued until the granular powder was dispersed in the solution for a sufficient time of 1 hour or more.

  The flow characteristics of the prepared palmitic acid coated granular powder were measured as described above. In the case of the stabilized zirconia granular powder before coating with palmitic acid, the flow characteristics are in a very low state, and it can be said that the measured value is almost zero level. On the contrary, the palmitic acid-coated granular powder had a remarkably improved flowability, and the flowability was 1.9084 g / s.

  When palmitic acid is coated by increasing the size distribution of the granular powder, it can be confirmed that the flow characteristics are improved to a high level. It is presumed that this is because the amount of static electricity on the surface of the coated powder decreases with respect to the volume of the powder, which makes it easy to maintain the separation between the powders.

  The thermal spray coating process was advanced using the prepared palmitic acid coated granular powder as described above.

  The coating amount of palmitic acid is preferably 0.01 wt% to 2.0 wt% with respect to granular powder, but is not limited thereto.

  FIG. 11 is an electron micrograph of a cross section of a thermal spray coated coating layer using a thermal spray powder according to a preferred embodiment of the present invention.

  FIG. 12 is an electron micrograph of a cross section of a coating layer measured by enlarging the area of the dash circle of FIG. 11 according to a preferred embodiment of the present invention.

  11 to 12 are photographs of samples of which thermal spray coatings were manufactured using the thermal spray powder manufactured in Example 2, and FIG. 12 is an enlarged photograph of the coating area 110, which is a thermal spray coated layer It can be seen that there are very few pores inside. The pore content of the thermal spray coating layer (thermal spray coating) using the thermal spray powder manufactured in Example 2 was about 5% when measured using an image analysis system.

  A thermal spray coating was manufactured using the thermal spray powder manufactured in Example 1, and the pore content was measured to be 6% or more. This means that the properties of the thermal spray coating can be controlled by controlling the flow properties of the thermal spray powder.

Example 3
0.2 g of palmitic acid is prepared, placed in a 200 ml beaker containing ethanol, and dissolved by sufficiently stirring for about 0.5 hours. Care is taken to maintain the amount of ethanol in the process of dissolving palmitic acid.

  10 g of plasma-surface-treated stabilized zirconia granule powder (plasma surface-treated stabilized zirconia granule powder) is added into the ethanol solution in which palmitic acid is dissolved, while stirring is continued until the total granule powder amount reaches 100 g. Do. The palmitic acid coating was advanced using plasma surface treatment stabilized zirconia granule powder having a size of 15 μm to 45 μm. Stirring was continued until the granular powder was dispersed in the solution for a sufficient time of 1 hour or more.

  The flow characteristics of the prepared palmitic acid coated granular powder were measured as described above. In the case of plasma surface-treated stabilized zirconia granule powder before coating with palmitic acid, the flow characteristics are in a very low state, and the measured value can be said to be almost zero level. On the contrary, the palmitic acid-coated granular powder had a significantly improved flowability, and the flowability was 2.0152 g / s.

  As described above, when the thermal spray coating process is performed using the prepared palmitic acid coated granular powder and the thermal spray coating film (thermal spray coating) is evaluated, it is at the same level as the thermal spray coating produced in Example 2, The internal pore content was within 5%.

  It can be seen that the flow characteristics are improved by coating the surface of the plasma surface-treated granular powder with an organic monomer. This is because the uniformity of the organic monomer coated on the surface of the powder is improved.

  In the case of using a thermal spray powder with improved flow characteristics, the usage time of the thermal spray gun can be extended, and the quality of the thermal spray coating can be improved. In addition, control of the properties of the thermal spray coating is further facilitated.

Comparative Example 3
0.2 g of polystyrene is prepared, placed in a 200 ml beaker containing ethanol, and dissolved by sufficiently stirring for about 0.5 hours.

  In the same manner as in Example 1, a polystyrene coating was developed on 100 g of plasma surface-treated stabilized zirconia powder. Moreover, the measurement of the flow characteristic with respect to the polystyrene-coated plasma surface treatment stabilized zirconia granule powder (polystyrene-coated granule powder) was performed. The flow rate of the polystyrene-coated granular powder was 0.4128 g / s.

  It was confirmed that the result of this comparative example 3 is not much different from that of the comparative example 1. This is because the choice of coating material has a great influence on the flow characteristics of the thermal spray powder.

  Besides the organic monomer material as described above, tetraethyl orthosilicate (TEOS) or hexamethyldisiloxane can be used to coat the surface of the granular powder. Also in this case, improved flow characteristics are exhibited.

  Moreover, as an organic monomer (monomer), styrene, acrylic acid, ethylene, acrylamide, methacrylic acid, acrylate, vinyl carboxylic acid, acrylonitrile (acrylonitrile (AN), propylene oxide (propylene oxide), silicone macromonomer, and butyl acrylate The surface of the granular powder can be coated by selecting at least one of the group consisting of

In addition, stearic acid (stearic acid, C ₁₇ H ₃₅ COOH), oleic acid (oleic acid, CH ₃ (CH ₂ ) ₇ CH = CH (CH ₂ ) ₇ COOH), eicosanoic acid as an organic monomer (monomer) At least one selected from the group consisting of (eicosanic acid, C ₁₉ H ₃₉ COOH), and docosanoic acid (C ₂₁ H ₄₃ COOH) can be selected to coat the surface of the granular powder.

  The granular powder whose surface is coated with the organic monomer is loaded into a thermal spray gun, and the thermal spray gun discharges the powder into a flame to carry out the thermal spray coating process. That is, the powder for thermal spray coating is a thermal spray powder, and a granular powder coated with an organic monomer or a granular powder subjected to plasma surface treatment can be used as the thermal spray powder.

10 Organic Monomer 20 Granule Powder Surface 30 Granule Powder 40 Plasma Surface Treated Granule Powder Surface 50 Plasma Surface Treated Granule Powder 60 Specific Gravity Cup 70 Sample Cup 80 Cup Distance 90 Powder Outlet 100 For Measurement Funnel 110 coating area

Claims (16)

Granule powder, and an organic monomer attached to the surface of the granule powder, high-fluidity sprayed powder. The granular powder is any one selected from the group consisting of ZrO ₂ , Y ₂ O ₃ , Al ₂ O ₃ , AlN, HfO ₂ , TiO ₂ , and stabilized zirconia. The high fluidity spray powder according to Item 1.   The high fluidity spray powder according to claim 2, wherein the granular powder is a powder produced through a granulation process.   The high fluidity spray powder according to claim 3, wherein the granular powder is a powder surface-treated by plasma.   The high fluidity spray powder according to claim 4, wherein the granular powder surface-treated by the plasma has a reduced surface roughness.   The high fluidity thermal spray powder according to claim 4, wherein the granular powder surface-treated by the plasma is a surface that is melted to increase the surface density.   The high fluidity thermal spray powder according to claim 6, wherein the granular powder is stabilized zirconia.   The high fluidity thermal spray powder according to claim 1, wherein the content of the organic monomer is in the range of 0.05 wt% to 5.0 wt% with respect to the weight of the granular powder.   The high fluidity thermal spray powder according to claim 1, wherein the organic monomer occupies 5% to 100% of the surface area of the granular powder.   The organic monomer is any one selected from the group consisting of an anionic surfactant, a cationic surfactant, an amphoteric surfactant, and a nonionic surfactant. The high fluidity spray powder according to claim 1. Examples of the organic monomer include palmitic acid, tetraethyl orthosilicate, hexamethyldisiloxane, acrylic acid, styrene, ethylene, acrylamide, methacrylic acid, acrylate, vinyl carboxylic acid, acrylonitrile acrylonitrile, propylene oxide, butyl acrylate, stearic acid (C ₁₇ H ₃₅ COOH), oleic acid, CH ₃ (CH ₂ ) ₇ CH = CH (CH ₂ ) ₇ COOH, eicosanoic acid _{(eicosanic acid, C 19 H 39} COOH), and docosane _{(Docosanoic acid, C 21 H 43} COOH) , wherein the selected from the group consisting of any one, high flow spray powder of claim 1. Preparing granular powder produced through granulation process,
Preparing an organic monomer solution by charging the organic monomer into a solvent;
A high-fluidity sprayed powder comprising the steps of: charging the granular powder into the organic monomer solution and mixing; and coating the organic monomer on the surface of the granular powder while evaporating the solvent. Production method. The granule powder according to claim 12, wherein the granule powder comprises any one selected from the group consisting of ZrO ₂ , Y ₂ O ₃ , Al ₂ O ₃ , AlN, HfO ₂ , TiO ₂ , and stabilized zirconia. Method of producing high flow spray powder. After the step of preparing the granular powder produced through the granulation process
The method of claim 12, further comprising plasma surface treating the granular powder.   The method according to claim 14, wherein the plasma surface treatment melts the surface of the granular powder to increase its surface density and reduce its surface roughness.   The method according to claim 15, wherein the granular powder is stabilized zirconia.