KR102478544B1 - Manufacturing method of yttria suspension for plasma spray coating - Google Patents

Abstract

The present invention relates to a method for manufacturing an yttria suspension for plasma thermal spray coating, and a method for manufacturing an yttria suspension for plasma thermal spray coating according to an embodiment of the present invention is a suspension by mixing yttria powder and a solvent in a predetermined ratio. preparing; ball milling the suspension; adding a certain amount of a dispersant to the ball milled suspension; and stirring the suspension to which the dispersant is added.

Description

Manufacturing method of yttria suspension for plasma spray coating {Manufacturing method of yttria suspension for plasma spray coating}

The present invention relates to a method for manufacturing a suspension of yttria (Y ₂ O ₃ ) for plasma thermal spray coating, and more particularly, to improve the density of a plasma thermal spray coated final product and to prevent peeling of the thermal spray coated coating layer. It relates to a method for manufacturing an yttria suspension for plasma thermal spray coating.

In the semiconductor and display industries, miniaturization of line width and high integration are continuously progressing, and a high-density plasma process is applied to manufacture high-density devices of several tens of nm or less.

Accordingly, in order to realize this, it is necessary to improve the technology of manufacturing process equipment such as thin film deposition technology (CVD) and etching technology, and to support ceramic materials used in process equipment.

On the other hand, the plasma thermal spray coating industry is a technology that melts/accelerates the material and coats it in the air by changing the coating equipment and coating technology according to the coating material and application. To improve durability and functionality against harsh plasma and chemical corrosion, semiconductor and Thermal spray coating of a ceramic material having plasma and chemical resistance is essential for display equipment members.

On the other hand, in the semiconductor dry etching process, products that minimize particle generation by plasma gas are required to minimize chip defects.

_At this time, particle generation is determined by the composition of the coating material and the densification of the plasma sprayed coating film _. It plays a pivotal role in the supply value chain.

On the other hand, looking at the direction of development in terms of the composition of the semiconductor member coating material, Anodizing was first introduced, and materials have been changed in the order of Al ₂ O ₃ and Y ₂ O ₃ .

In this regard, in order to improve the density of the thermal spray coating film, the initial product, 10 ~ 63㎛ size spray powder, was applied, but the particle size was reduced to 15 ~ 45㎛ (D ₅₀ 35㎛) to form a dense film. Thermal spray powder is being commercialized.

On the other hand, in order to improve the density of a better thermal spray coating, research on Suspension Plasma Spray (SPS), which is capable of denser coating than atmospheric plasma thermal spray coating, which is a commercialized coating method, was urgently needed, and advanced ceramic materials companies abroad jointly Ceramic coating technology and related materials (yttria dry powder for atmospheric plasma, wet yttria slurry for suspension plasma) are being actively developed to improve plasma properties.

On the other hand, in the case of domestic companies and research institutes, the yttria suspension technology for suspension plasma spray coating was mainly imported from abroad to conduct research and development. Accordingly, it is urgent to secure domestic technology for the well-dispersed yttria suspension manufacturing technology. .

On the other hand, since the suspension using conventional sub-micron size powder was not optimized, there was a high possibility of problems such as the density of the final product and the peeling of the coating film layer after thermal spray coating. In order to develop the optimal slurry for increasing the yttria suspension, it is necessary to optimize the dispersion state.

The present invention is to solve the above-mentioned problems and to provide an alternative to the necessary situation, and to improve the density of the final product subjected to plasma spray coating and to prevent the peeling of the spray coated coating film layer. Yttria suspension for plasma spray coating. The purpose is to provide a manufacturing method.

On the other hand, the object of the present invention is not limited to the purpose mentioned above, and other objects not mentioned will be clearly understood by those skilled in the art from the description below.

A method for preparing a suspension of yttria for plasma thermal spray coating according to an embodiment of the present invention includes preparing a suspension by mixing yttria powder and a solvent in a predetermined ratio to achieve the above object, ball milling the suspension The method may include adding a certain amount of a dispersant to the ball milled suspension and stirring the suspension to which the dispersant is added.

On the other hand, a method for manufacturing an yttria suspension for plasma thermal spray coating according to another embodiment of the present invention includes preparing a suspension by mixing yttria powder and a solvent in a predetermined ratio to achieve the above object, It may include a step of milling, adding a certain amount of a pH adjusting agent to the ball milled suspension, and adjusting the pH while stirring the suspension to which the pH adjusting agent is added.

Preferably, DI water is used as the solvent, and the yttria powder and the solvent may be mixed in a weight ratio of 10:90.

Preferably, the step of ball milling the suspension may be ball milling for 2 hours using zirconia balls.

Preferably, the dispersing agent may use any one selected from the group consisting of anionic, cationic and zwitterionic dispersants.

Preferably, the dispersant may be added in an amount of 1 to 3 wt% based on the total weight of the suspension.

Preferably, HCl and NH ₃ are used as the pH adjusting agent, and the step of adjusting the pH while stirring the suspension to which the pH adjusting agent is added can be adjusted so that the pH of the suspension is 7 to 9.

The method of manufacturing an yttria suspension for plasma thermal spray coating according to embodiments of the present invention has an excellent effect of improving the density of a plasma thermal spray coated final product and preventing peeling of the thermal spray coated coating film layer.

1 is an image showing the microstructure of yttria powder particles according to an embodiment of the present invention.
Figure 2 is particle size distribution data with the addition of a cationic dispersant in one embodiment of the present invention. ((a) 1wt%, (b) 3wt%)
3 is a sedimentation image of an yttria suspension to which an anionic dispersant is added in one embodiment of the present invention.
4 is a sedimentation image of an yttria suspension to which a cationic dispersant is added in one embodiment of the present invention.
5 is a sedimentation image of an yttria suspension to which a zwitterion dispersant is added in one embodiment of the present invention.
6 is a sedimentation image of an yttria suspension by pH control in another embodiment of the present invention.

The terms used in the present invention have been selected from general terms that are currently widely used as much as possible, but in certain cases, there are terms arbitrarily selected by the applicant. should be taken into account to understand its meaning.

Hereinafter, the technical configuration of the present invention will be described in detail with reference to preferred embodiments shown in the accompanying drawings.

In this regard, first, Figure 1 is an image showing the microstructure of yttria powder particles according to an embodiment of the present invention, Figure 2 is particle size distribution data ((a) 1wt with the addition of a cationic dispersant in one embodiment of the present invention %, (b) 3wt%), Figure 3 is an image of the precipitation of the yttria suspension to which an anionic dispersant was added in one embodiment of the present invention, Figure 4 is a yttria to which a cationic dispersant was added in one embodiment of the present invention Sedimentation image of the suspension, FIG. 5 is a precipitation image of the yttria suspension to which the zwitterion dispersant is added in one embodiment of the present invention, and FIG. 6 is the precipitation image of the yttria suspension by pH adjustment in another embodiment of the present invention. Precipitation is also an image.

1 to 5, the method for preparing a suspension of yttria for plasma spray coating according to an embodiment of the present invention includes preparing a suspension by mixing yttria powder and a solvent in a predetermined ratio. do.

At this time, in one embodiment of the present invention, various solvents may be used as the solvent, but in one embodiment of the present invention, the solvent is DI water (Deionized Water), and the yttria powder and the solvent are 10 : 90 by weight.

On the other hand, the method of manufacturing an yttria suspension for plasma thermal spray coating according to an embodiment of the present invention includes the step of ball milling the suspension.

At this time, the ball milling step may be performed using various devices and instruments, but in one embodiment of the present invention, ball milling is performed for 2 hours using zirconia balls.

On the other hand, the method for preparing the yttria suspension for plasma thermal spray coating according to an embodiment of the present invention includes adding a certain amount of a dispersant to the ball milled suspension.

At this time, the dispersant uses any one selected from the group consisting of anionic, cationic and zwitterionic dispersants, and more specifically, the dispersants are products of BYK, the anionic dispersant is DISPERBYK-102, and the cationic dispersant is DISPERBYK-163 , Use the zwitterionic dispersant DISPERBYK-180.

On the other hand, the dispersant may be added within various ranges, but in one embodiment of the present invention, the dispersant is 1 to 3 wt based on the total weight of the suspension so that the yttria powder can be optimally dispersed in the solvent. % is added.

In addition, the method for preparing the yttria suspension for plasma thermal spray coating according to an embodiment of the present invention includes stirring the suspension to which the dispersant is added.

At this time, since the step of stirring the suspension may be stirred using various stirrers, there is no particular limitation thereon.

Hereinafter, the dispersion effect of the yttria suspension for plasma thermal spray coating prepared according to an embodiment of the present invention will be described in detail.

In this regard, first of all, in the present specification, the dispersion degree of the yttria suspension is the smaller the average particle diameter of the particles in the slurry and the lower the viscosity of the slurry, the better the dispersion degree. The more visible, the better the dispersion.

In this regard, referring to Table 1 and Fig. 2, which show the particle size distribution of the yttria suspension according to the addition of the dispersant,

Particle size distribution of yttria suspension according to addition of dispersant division Average particle size (μm) d ₁₀ (μm) d ₅₀ (μm) d ₉₀ (μm) DISPERBYK-102
anion 1wt% 2.57 0.356 2.301 5.218 2wt% 23.69 6.068 16.54 35.83 3wt% 27.25 3.087 23.39 53.94 DISPERBYK-163
cation 1wt% 1.326 0.299 1.1014 2.683 2wt% 4.75 0.699 2.323 11.82 3wt% 2.557 0.332 1.329 5.71 DISPERBYK-180
zwitterion 1wt% 3.537 0.553 3.441 6.381 2wt% 4.077 0.352 3.922 7.652 3wt% 5.097 0.503 4.773 9.38

When 1 wt% of the anionic dispersant was added, the average particle size increased, but there was no significant difference from the yttria starting particle size. μm, 3 wt% showed a d ₅₀ value of 23.39 μm.

On the other hand, when the cationic dispersant was used, there was no rapid change as in the anionic dispersant, and the average particle size was 1.326μm at 1wt%, _4.75μm at 2wt%, and 2.557 at 3wt%. It was confirmed as 2.323 μm and 1.329 μm.

In addition, in the case of the zwitterionic dispersant, it was confirmed that the average particle size increased as the addition amount increased, although it was smaller than that of the anionic dispersant, and when only the particle size distribution was confirmed, the most effective dispersant was DISPERBYK-163 cationic dispersant, and the addition amount was It was confirmed that 1wt% or 3wt%.

Hereinafter, the dispersing effect of the yttria suspension for plasma thermal spray coating prepared according to an embodiment of the present invention will be described in detail with reference to Table 2 showing the viscosity measurement results of the yttria suspension according to the addition of the dispersant.

[Viscosity measurement of yttria suspension according to additives] (Unit: cP) division Primary Secondary tertiary DISPER BYK-102
anion 1wt% 10 9 9 2wt% 21 20 17 3wt% 25 22 21 DISPER BYK-163
cation 1wt% 13 11 10 2wt% 11 11 10 3wt% 11 11 10 DISPER BYK-180
zwitterion 1wt% 16 15 14 2wt% 15 14 14 3wt% 12 12 12

At this time, the data in Table 2 is the result of the first, second and third viscosity measurements, the first is the viscosity value immediately after measurement, the second is the viscosity value in a state where the measurement has progressed to some extent, and the third is the change in the value It means the viscosity value in a state where it is not, and the lower the cP (centi Poise) value, the lower the viscosity, and the higher the value, the higher the viscosity.

Referring to Table 2, in the case of the anionic dispersant, the cP value increased rapidly when 2 wt% or more was added, and the cationic dispersant showed similar values immediately after measurement for each amount added, but the measurement finish value was 10, confirming the same.

On the other hand, the zwitterionic dispersant did not show a rapid change according to the amount added like the anionic dispersant, but it was confirmed that the cP value decreased as the amount added increased. , it was confirmed that it had an appropriate viscosity value.

Hereinafter, the experimental results of sedimentation of the yttria suspension according to the amount of the dispersant prepared according to an embodiment of the present invention will be described in detail.

In this regard, first, the sedimentation degree test was measured using a 25 mL measuring cylinder.

More specifically, the degree of sedimentation was measured for 6 hours immediately after the suspension was prepared, and then the height of the precipitate, the height of the solution, the height of the transparent solution, and the turbidity of the solution were measured on a daily basis, and the precipitate was excluded over time. It was separated into two layers and the height of the solution and the height of the transparent solution were measured accordingly.

At this time, in the case of the height of the solution, it means a state in which yttria powder is floating and looks hazy, and in the case of the height of a transparent solution, it means a state in which yttria powder is not floating and looks transparent, and the turbidity of the solution is arbitrarily A, It is divided into B and C. In the case of A, it means a state that looks completely hazy, in the case of C, it means a state that is transparent or about to be transparent, and in the case of B, it means an intermediate level between A and C.

On the other hand, referring to Table 3 and FIG. 3, which are the results of the precipitation test according to the amount of the anion dispersant added,

[Precipitation test according to the amount of anion dispersant added] division 1H 2H 3H 4H 5H 6H 1D 2D 3D 4D 5D 6D 1wt% sedimentary
Height (mL) 7 7 6 6 6 6 6 5 5 5 5 5 turbidity of the solution B B B B B B B B B B- B- B- 2wt% sedimentary
Height (mL) 10 10 9 9 9 8 8 7 7 7 6 6 turbidity of the solution C C C C C C C C C C C C 3wt% sedimentary
Height (mL) 9 9 9 9 9 9 8 8 8 8 7 7 turbidity of the solution B B B B B B C C C C C C

In the case of the anionic dispersant, agglomeration occurred at 1 wt% and 3 wt%, and a phenomenon of sticking to the wall of the measuring cylinder (a kind of aggregation phenomenon) occurred. Except for the attached yttria aggregates, the solution was judged to be almost clear.

On the other hand, referring to Table 4 and FIG. 4, which are the results of the precipitation degree test according to the addition amount of the cation dispersant,

[Precipitation test according to the amount of cationic dispersant added] division 1H 2H 3H 4H 5H 6H 1D 2D 3D 4D 5D 6D 1wt% sedimentary
Height (mL) - - - - - - - - - - - - turbidity of the solution A A A A A A A A A A- A- A- 2wt% sedimentary
Height (mL) - - - - - - - - - - - - turbidity of the solution A A A A A A A A A A- A- A- 3wt% sedimentary
Height (mL) - - - - - - - - - - - - turbidity of the solution A A A A A A A A A A A A-

When the cationic dispersant was added, it was difficult to check the height of the precipitate due to high turbidity as a whole, and it was confirmed that the dispersion was well made overall despite the 6-day precipitation test.

In addition, referring to Table 5 and FIG. 5, which are the results of the precipitation degree test according to the amount of the cationic dispersant added,

[Precipitation test according to the addition amount of amphoteric ion dispersant] division 1H 2H 3H 4H 5H 6H 1D 2D 3D 4D 5D 6D 1wt% sedimentary
Height (mL) 9 9 9 9 9 9 9 9 9 9 9 9 turbidity of the solution C C C C C C C C C C C C 2wt% sedimentary
Height (mL) 6 6 6 6 6 6 6 6 6 6 6 6 turbidity of the solution A A A A A A- A- A- B+ B B B 3wt% sedimentary
Height (mL) - - - - - - 5 5 5 5 5 5 turbidity of the solution A A A A A A A- A- B+ B B- B-

When 1 wt% of the zwitterion dispersant was added, only a transparent solution layer was shown in 1 hour and the turbidity was very low. In the case of 2 wt% and 3 wt%, the dispersion was maintained for a short time, but the It was confirmed that the more transparent the solution layer was, the aggregation occurred, and the precipitation layer became clear.

Hereinafter, a method for manufacturing an yttria suspension for plasma thermal spray coating according to another embodiment of the present invention will be described in detail.

In this regard, first, a method for preparing an yttria suspension for plasma thermal spray coating according to another embodiment of the present invention includes preparing a suspension by mixing yttria powder and a solvent in a predetermined ratio, ball milling the suspension, Adding a predetermined amount of a pH adjusting agent to the ball milled suspension and adjusting the pH while stirring the suspension to which the pH adjusting agent is added.

At this time, since the step of preparing the suspension and the step of ball milling are the same as those of the above-described embodiment, a detailed description thereof will be omitted.

Meanwhile, in the step of adding a certain amount of pH adjusting agent to the suspension, various pH adjusting agents may be used, but in another embodiment of the present invention, HCl and NH ₃ are used as the pH adjusting agent, and the pH adjusting agent is added to the suspension. In the step of adjusting the pH while stirring, the pH of the suspension is adjusted to be 7 to 9 using the pH adjusting agent.

Hereinafter, the effects of other embodiments of the present invention will be described in detail with reference to FIG.

[Precipitation degree test according to pH control] division 1H 2H 3H 4H 5H 6H 1D 2D 3D 4D 5D 6D pH 1 sedimentary
Height (mL) One One One One One One One One One One One One turbidity of the solution C+ C+ C+ C+ C+ C+ C C C C C C pH 5 sedimentary
Height (mL) One One One One One One One One One One One One turbidity of the solution C+ C+ C+ C+ C+ C+ C C C C C C pH 7 sedimentary
Height (mL) - - - - - - 17 17 17 17 17 17 turbidity of the solution A A A A A A A A- A- A- B+ B+ pH 9 sedimentary
Height (mL) - - - - - - - - - 10 10 10 turbidity of the solution A A A A A A A A B+ B+ B B pH 11 sedimentary
Height (mL) - - - - - - 7 3 3 2 2 2 turbidity of the solution A A A A A A C C C C C C

Referring to FIG. 6 and Table 6, it was confirmed that after the precipitation test was started at pH 1 and pH 5, the precipitation was rapidly precipitated and separation occurred, and slight turbidity was seen until 6 hours. In the case of pH 7, the transparent solution was slightly It was confirmed that there was turbidity and that the solution layer was separated separately from this.

On the other hand, the height of the precipitate at pH 9 could be confirmed only on the 4th day, and pH 11 was rapidly precipitated and separated after one day of measurement, and only a transparent solution was shown as a whole.

Accordingly, the yttria suspension for plasma thermal spray coating prepared according to the embodiments of the present invention was able to obtain a well-dispersed yttria suspension when a cationic dispersant was used, and was widely dispersed in the range of 1 wt% to 3 wt% It was confirmed that this was done, and in pH control, it was confirmed that excellent dispersion behavior was shown in the pH range of 7 to 9.

As a result, the manufacturing method of the yttria suspension for plasma thermal spray coating according to the embodiments of the present invention can improve the density of the final product coated with plasma thermal spray and prevent peeling of the thermal spray coated coating layer through the above-described technical configurations. It is possible to manufacture yttria suspension for plasma thermal spray coating.

As reviewed above, the present invention has been shown and described as a preferred embodiment, but is not limited to the above-described embodiments, and to those skilled in the art within the scope of not departing from the spirit of the present invention Various changes and modifications will be possible.

Claims (8)

preparing a suspension by mixing yttria powder and a solvent at a predetermined ratio;
ball milling the suspension;
adding a certain amount of a dispersant to the ball milled suspension; and
Stirring the suspension to which a dispersant is added,
The dispersant uses any one selected from the group consisting of anionic, cationic and zwitterionic dispersants, the anionic dispersant is DISPERBYK-102, the cationic dispersant is DISPERBYK-163, the amphoteric dispersant is DISPERBYK-180,
The dispersant is a method for producing an yttria suspension for plasma spray coating, characterized in that 1 to 3 wt% is added relative to the total weight of the suspension.
preparing a suspension by mixing yttria powder and a solvent at a predetermined ratio;
ball milling the suspension;
adding a certain amount of a pH adjusting agent to the ball milled suspension; and
Adjusting the pH while stirring the suspension to which the pH adjusting agent is added,
The pH adjusting agent uses HCl and NH ₃ , and the step of adjusting the pH while stirring the suspension to which the pH adjusting agent is added is adjusting the pH of the suspension to be 7 to 9. Manufacturing method of yttria suspension.
According to claim 1 or 2,
The method of producing an yttria suspension for plasma thermal spray coating, characterized in that the solvent uses DI water and the yttria powder and the solvent are mixed in a weight ratio of 10:90.
According to claim 1 or 2,
Ball milling the suspension is a method for producing an yttria suspension for plasma thermal spray coating, characterized in that ball milling for 2 hours using a zirconia ball.
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