TW201815673A - High hardness TaC coated carbon material and manufacturing method for same - Google Patents

Abstract

According to one embodiment of the present invention, a carbon base material; and a TaC coating layer formed on the carbon base material. Provided is a high hardness TaC coating carbon material, comprising 15-20 volume% of content of Tac of 150 [mu]m of depth from a surface of the carbon base material.

Description

High-hardness TaC coating carbon material and preparation method thereof

The invention relates to a carbon substrate and a high-hardness TaC coating carbon material with a high adhesion TaC coating formed on the carbon substrate and a preparation method thereof.

Studies on introducing thin films of various materials on the surface of a substrate to improve the abrasion resistance and corrosion resistance of the materials are being carried out in various aspects. Among them, tantalum carbide (TaC) coatings have attracted attention because they have more excellent properties than conventional thin film materials in terms of heat resistance, abrasion resistance, and gas etching resistance. Recently, tantalum carbide-coated carbon materials having a TaC coating formed on the carbon materials are being used in various industrial sites such as semiconductor single crystal manufacturing equipment parts, precision work tools, and engine parts.

However, the TaC coating thus formed has various problems in terms of adhesion to a carbon substrate. Therefore, in order to increase the adhesion on the carbon substrate while increasing the surface hardness, various researches on the TaC thin film coating method have been recently conducted.

Technical topics

An object of the present invention is to provide a TaC-coated carbon material with excellent physical properties, has excellent adhesion to a carbon substrate, and has high hardness.

However, the problems to be solved by the present invention are not limited to the problems mentioned above, and those skilled in the art with ordinary knowledge can clearly understand the unmentioned or other problems through the following description.

Technical solutions

According to an embodiment of the present invention, a high-hardness TaC-coated carbon material is provided, including: a carbon substrate; and a TaC coating formed on the carbon substrate and having a depth of 150 μm from the surface of the carbon substrate. The TaC content in the region is 15 vol% to 20 vol%.

According to an embodiment of the present invention, a high-hardness TaC-coated carbon material is provided. The TaC content from a region with a depth of 80 μm from the surface of the carbon substrate is 16 vol% to 20 vol%, and the depth from the surface of the carbon substrate is The TaC content in the region of 80 μm to 150 μm is 13 vol% to 18 vol%.

According to an embodiment of the present invention, a high-hardness TaC coating carbon material is provided, and a surface scratch value of the TaC coating is 3.5N or more.

According to an embodiment of the present invention, a high-hardness TaC coating carbon material is provided. The surface scratch value of the TaC coating is obtained by the following mathematical formula 1. [Mathematical formula 1] Surface scratch value (N) = from The carbon substrate has a TaC content (vol%) x (1.4 to 1.6) -19.5 in a region having a surface depth of 80 μm to 150 μm.

According to an embodiment of the present invention, a method for preparing a high-hardness TaC-coated carbon material is provided, including the following steps: preparing a carbon substrate having an average porosity of 15 vol% -20 vol%; and forming a carbon substrate on the surface of the carbon substrate TaC coating.

According to an embodiment of the present invention, a method for preparing a high-hardness TaC-coated carbon material is provided. The step of forming the TaC coating is to immerse TaC in the pores of the carbon substrate. A TaC-impregnated area is formed inside to contact the TaC coating.

According to an embodiment of the present invention, a method for preparing a high-hardness TaC-coated carbon material is provided. The step of preparing the carbon substrate is prepared by the following mathematical formula 2 according to the following formula: For a carbon substrate having the average porosity that requires a surface scratch value, [Mathematical formula 2] The average porosity (vol%) of the carbon substrate = (surface scratch value N + 19.5) x (0.65 to 0.7).

According to an embodiment of the present invention, a method for preparing a high-hardness TaC-coated carbon material is provided. The step of forming the TaC coating is performed by using chemical vapor deposition (CVD) at a temperature of 1900 ° C to 2500 ° C.

According to an embodiment of the present invention, a method for preparing a high-hardness TaC coating carbon material is provided. The steps of forming the TaC coating are performed multiple times to form multiple TaC coatings. Technical effect

According to an embodiment of the present invention, a carbon material may be provided, which contains a high-hardness TaC coating with excellent adhesion. Therefore, the carbon material according to an embodiment of the present invention can be used in various industrial equipment including semiconductor production equipment in various coating materials requiring excellent adhesion and hardness.

Hereinafter, embodiments of the high-hardness TaC-coated carbon material of the present invention and a preparation method thereof will be described in detail with reference to the accompanying drawings. The embodiments and drawings described below can be variously changed. In addition, irrespective of the reference signs, the same structural elements are attached to the same element signs, and repeated descriptions thereof are omitted. The embodiments described below are not intended to limit the embodiments, and it should be understood that they include all changes, equivalents, and alternatives of the embodiments. In the description of the present invention, detailed descriptions of known properties or structures are judged to obscure the gist of the present invention, and detailed descriptions are omitted.

In addition, the technical terms used in the present invention, as the terms used to appropriately represent the preferred embodiments of the present invention, differ according to the intention of the user, the operator, or the rules of the field to which the present invention belongs. Therefore, the definition of technical terms should be based on the entire content of this specification. The same element symbols shown in the drawings indicate the same components.

Throughout the specification, when a component is "on" another component, it not only means that the component is in contact with another component, but also includes the case where there are other components between the two components.

Throughout the specification, when describing a "contained" part of a certain structural element, it does not mean that other structural elements that are not described to the contrary are excluded. It may also refer to further including other structural elements.

Generally, problems in the process of forming a TaC coating on a carbon material are the hardness of the applied TaC layer and the adhesion of the carbon material as a substrate. Related studies have recently been conducted in various aspects to improve the hardness and adhesion of TaC coatings that vary according to various physical properties of the substrate. The purpose of the present invention is to continue the above research, focusing on the porosity of carbon materials, and proposing carbon materials suitable for TaC coatings.

According to an embodiment of the present invention, a high-hardness TaC coating carbon material is provided, including: a carbon substrate; and a TaC coating formed on the carbon substrate, and a depth of 80 μm from a surface of the carbon substrate- The TaC content in the 150 μm region is 15 vol% to 20 vol%.

The carbon substrate may be any substrate containing graphite and containing carbon as a main component. The TaC coating may include any material mainly composed of tantalum (Ta) and carbon (C). FIG. 1 is a conceptual cross-sectional view of a carbon substrate (110) containing pores provided in an embodiment of the present invention.

2 is a conceptual cross-sectional view illustrating a high-hardness TaC-coated carbon material according to an embodiment of the present invention, which includes a carbon substrate containing a TaC component impregnated region (130) and a TaC coating formed on the carbon substrate ( 120). The impregnated region (130) may include a region (131) having a depth of 80 μm to 150 μm from the surface of the carbon substrate. A region having a depth of 80 μm to 150 μm from the surface of the carbon substrate may be a region formed by immersing the TaC component of the TaC coating in the pores of the carbon substrate, which is actually the surface hardness of the coating and the substrate. The area where adhesion is affecting.

In addition, the TaC content in the region from the surface of the carbon substrate to a depth of 80 μm to 150 μm is 15 vol% to 20 vol%. When the TaC content is 15 vol% to 20 vol%, a high-hardness TaC-coated carbon material with excellent adhesion and surface hardness proposed in one aspect of the present invention can be realized. When the TaC content in the region is 15 vol% or less, the adhesion with the TaC coating is weak, and there is a problem that the surface hardness is insufficient. When the TaC content exceeds 20 vol%, graphite pores are excessively formed, and there is a problem that the surface roughness is increased or the coating surface is formed coarsely. Further, it is preferable that the TaC content of the region is 16.5 vol% to 20 vol%. Further, it is more preferable that the TaC content of the region is 18 vol% to 20 vol%. When the TaC content in the region increases, it means that the porosity on the carbon substrate is higher, and in fact, the TaC coating material formed on the carbon substrate with higher porosity has more excellent adhesion and surface hardness. .

As an example of the present invention, the TaC content from a region with a depth of 40 μm to 75 μm on the surface of the carbon substrate is 16 vol% to 20 vol%, and the TaC content from a region with a depth of 75 μm to 150 μm on the surface of the carbon substrate may be 13vol% -18vol%.

As shown in FIG. 2, a region (131) having a depth of 80 μm to 150 μm from the surface of the carbon substrate can be divided into two regions having different TaC contents: a first region having a depth of 40 μm to 75 μm from the surface of the carbon substrate. (132), and a second region (133) having a depth of 75 μm to 150 μm from the surface of the carbon substrate.

The first region, as a layer adjacent to the TaC coating layer, is a region where the TaC component can be sufficiently impregnated into the pores of the substrate. Therefore, it is the region with the highest impregnation rate among the carbon substrates. Although the adhesion and surface hardness of the TaC coating formed on the carbon substrate may vary according to engineering conditions such as engineering temperature and Ta / C ratio, the TaC of the first region after the TaC coating is formed When the content is 16vol% -20vol%, it can have excellent surface hardness. The second region is deeper from the surface of the substrate than the first region, and as a layer adjacent to the first region, is a region where the TaC component of the coating is relatively less impregnated. However, the TaC content in this region also affects the adhesion and surface hardness of the TaC coating formed on the carbon substrate. When the TaC content in the second region is 13 vol% to 18 vol%, the TaC coating formed on the carbon substrate may have excellent adhesion and surface hardness. The TaC content of the first and second regions may be gradually changed.

According to an example of the present invention, a surface scratch value of the TaC coating may be 3.5N or more. As a method for determining the excellent adhesion of the TaC coating, similar to a 4-Point Bending test, Peel-Off test, Scotch tape test, Various test methods such as adhesion strength test. Among them, the Scratch Test is also a test method for determining adhesion that is easy to prepare and convenient to detect, and is often used in the industry. In the scratch test, a stylus with a round end is used to increase the surface load of the film, and at the same time, the substrate is moved, and the adhesion is calculated by the critical load value when the film is peeled off. Therefore, a higher scratch value indicates stronger adhesion. The surface scratch value of the TaC coating of the high-hardness TaC coating carbon material provided through an example of the present invention may be 3.5N or more. In addition, the surface scratch value of the TaC coating is preferably 3.5N or more. When the surface scratch value of the TaC coating is less than 3.5N, the adhesion to the surface of the substrate is insufficient, which has a problem that it is difficult to be applied in the industry. In addition, it is more preferable that the surface scratch value of the TaC coating is 8.0 N or more. It was found here that when the TaC content from a region having a depth of 80 μm to 150 μm on the surface of the carbon substrate increases, the surface scratch value also increases uniformly. The TaC content is determined after the TaC component is impregnated into the pores on the carbon substrate. Therefore, when the average porosity of a region with a depth of 80 μm to 150 μm on the surface of the carbon substrate increases, the TaC coating is applied. The adhesion between the layer and the carbon substrate is increased.

According to an example of the present invention, the surface scratch value of the TaC coating can be obtained by the following mathematical formula 1. [Mathematical formula 1] Surface scratch value (N) = TaC content (vol%) x (1.4 to 1.6) -19.5 from a region where the surface depth of the carbon substrate is 80 μm to 150 μm.

There are various reasons for determining the adhesion of the TaC coating formed on the carbon substrate. As described above, the TaC content in the region from the surface of the carbon substrate to a depth of 80 μm to 150 μm, that is, the TaC of the portion. The amount of component impregnation has a large effect on the adhesion of the TaC-coated carbon substrate. According to an example of the present invention, the surface scratch value (N) of the TaC coating is based on a linear function formula in which the TaC content (vol%) from a region with a carbon substrate surface depth of 80 μm to 150 μm is a variable. different. The surface scratch value (N) of the TaC coating determined accordingly is equal to the value of the TaC content (vol%) x (1.4 to 1.6) -19.5 in a region from the surface depth of the carbon substrate of 80 μm to 150 μm.

According to another embodiment of the present invention, a method for preparing a high-hardness TaC-coated carbon material is provided, including the following steps: preparing a carbon substrate having an average porosity of 15 vol% to 20 vol%; and forming a carbon substrate on the surface of the carbon substrate TaC coating. In one embodiment of the present invention, in order to prepare a high-hardness TaC-coated carbon material with good adhesion, the method may include: preparing a carbon substrate having an average porosity of 15 vol% to 20 vol%. Since a carbon substrate having an average porosity of 15 vol% to 20 vol% is prepared, a high-hardness TaC-coated carbon material with excellent adhesion and surface hardness, which is proposed in one embodiment of the present invention, can be realized. In addition, the average porosity is preferably 16.5 vol% to 20 vol%. In addition, the average porosity is more preferably 18 vol% to 20 vol%. The increase in the TaC content in the carbon substrate indicates that the porosity on the carbon substrate is smaller than High, and in fact, the higher the porosity of the TaC coating material formed on the carbon substrate, the more excellent the adhesion and surface hardness. The method for detecting the average porosity of the carbon substrate can be detected by a mercury adsorption method by using a Porosiemeter.

As an example of the present invention, the step of forming a TaC coating layer may include: immersing a TaC component into the pores of the carbon substrate, thereby forming an impregnated region in contact with the TaC coating layer inside the carbon substrate. . When the TaC coating on the carbon substrate is formed at a high temperature, the TaC component is immersed from the surface pores of the carbon substrate into the pores in the interior. As a result, an impregnated region in contact with the TaC coating can be formed inside the carbon substrate. A region having a depth of 80 μm to 150 μm from the surface of the carbon substrate from the impregnated region may be a region having practical meaning when determining the adhesion and surface hardness of the TaC-coated carbon material.

According to an example of the present invention, the step of preparing the carbon substrate may be prepared by the following mathematical formula 2 with the average porosity based on the required surface scratch value of the high-hardness TaC-coated carbon material. Carbon substrate. [Mathematical formula 2] The average porosity (vol%) of the carbon substrate = (surface scratch value N + 19.5) x (0.65 to 0.7).

That is, based on the mathematical formula 2, the porosity of the substrate can be adjusted to control the physical properties of the surface of the TaC coating.

There are various reasons for determining the adhesion of the TaC coating formed on the carbon substrate, and as described above, the average porosity of the carbon substrate has a large adhesion to the TaC coating. Impact. The average porosity of the carbon substrate according to an example of the present invention is different from the linear equation of the variable value of the surface scratch value of the TaC coating as in the examples described later. The average porosity of the carbon substrate determined based on this is equal to a value of (surface scratch value N + 19.5) x (0.65 to 0.7). Therefore, according to one aspect of the present invention, the required adhesion of the TaC coating is calculated according to the use of materials in the industrial field, and converted into a surface scratch value, so that it can be prepared in advance for the manufacturing process. Effect of carbon substrate.

According to an example of the present invention, the step of forming a TaC coating may be performed at a temperature of 2000 ° C. to 2500 ° C. using a chemical vapor deposition method. The step of forming a TaC coating on the surface of the carbon substrate may be performed by a chemical vapor deposition (CVD) method, a sputtering method, a conversion method (CVR), a spray method, or a physics method. A vapor deposition (PVD) method is performed. In particular, the CVD method has the advantage that a thinner layer can be formed at a faster speed even in a larger substrate area to deposit a coating.

According to an example of the present invention, the step of forming a TaC coating may be performed at 1900 degrees Celsius to 2500 degrees Celsius. In the step of forming the TaC coating, the higher the engineering temperature, the larger the surface grains of the TaC coating, and the surface hardness and wear resistance of the TaC coating can be improved. When the temperature is below 1900 degrees Celsius, the vapor deposition rate of the TaC coating is reduced, or the problem of unstable crystallization is observed. And when it exceeds 2500 degrees Celsius, the equipment cost increases, and the temperature is high, it is difficult for the TaC component to be impregnated into the pores of the carbon substrate, and there is a problem that the adhesion is reduced. Preferably, it is performed at a temperature of 1900 degrees Celsius to 2300 degrees Celsius

According to an example of the present invention, the step of forming a TaC coating may be performed multiple times, thereby forming multiple TaC coatings. That is, a process of forming a TaC coating layer more than twice may be included, and thus, a method of preparing a carbon material in which two or more TaC coating layers are formed may be included. It may further include forming an additional TaC coating, and performing a process for forming more than 3, 4 more coatings to form more coatings.

FIG. 3 is a conceptual cross-sectional view illustrating a high-hardness TaC-coated carbon material according to another embodiment of the present invention, including a carbon substrate and a plurality of TaC coatings on which a plurality of layers are formed. By using the TaC coating formation steps described above to form multiple TaC coatings, it can be determined that the first coating (121) formed during the initial coating formation has a second coating (122) and Third coating (123). The size of the crystal grains of the TaC coating becomes one of the reasons for determining the surface hardness of the coating formed. When the TaC coating is deposited again on the TaC coating, compared with forming only one TaC coating, the crystal grains of the TaC coating forming the outer surface of the material become larger, so that the surface hardness can also be increased. Thereby, a method for preparing a high-hardness TaC coating carbon material including a process of forming a TaC coating multiple times, which is proposed in one aspect of the present invention, can be realized.

Hereinafter, the present invention will be described in detail with reference to the following examples and comparative examples. However, the technical idea of the present invention is not limited or limited by this.

Examples

The TaC-coated carbon material proposed in one embodiment of the present invention was prepared by chemical vapor deposition (CVD). According to an embodiment of the present invention, for a carbon substrate having an average porosity, a thermal expansion coefficient of 4.9 to 6.0 × 10-6 / K, a diameter of 400 mm, and a thickness of 10 mm, the temperature is 2000 degrees Celsius and the pressure is 500 Torr and T precursor (TaCl ₅ ) 5000 sccm (standard-state cubic centimeter per minute), C precursor (CH ₄ ) 50 sccm chemical vapor deposition Under the conditions of CVD process, a TaC coating was prepared. In this case, the C / Ta ratio of the tantalum carbide coating is adjusted to 1: 1.05. The porosity of each carbon substrate was measured by a mercury adsorption method.

The high-hardness TaC-coated carbon materials prepared in the above conditions were each subjected to a scratch test. Table 1 below shows the values of the scratch test results for the examples and comparative examples 1 and 2 of the carbon substrate of the high-hardness TaC-coated carbon material provided in one example of the present invention. [Table 1]

The examples 1 to 3 are carbon substrates provided in one aspect of the present invention, and a TaC coating is formed on the carbon substrate with an average porosity of the carbon substrate of 15 vol% to 20 vol% under the engineering conditions. According to the test results, it was found that when a carbon substrate having an average porosity of 15 vol% to 20 vol% of the carbon substrate provided in one embodiment of the present invention was used, the scratch value showed a value of 3.5N or more. value. In contrast, when a carbon substrate having an average porosity of 15 vol% or less was used, the scratch value was a value of 3.5N or less. It can be known from this that, when using a carbon substrate having an average porosity of 15 vol% or less, it is difficult to reflect the high adhesion force proposed in one embodiment of the present invention.

It can be known from this test that when the average porosity of the carbon substrate is high, the adhesion of the TaC coating of the carbon substrate can be increased. In addition, through test results, it was found that between the average porosity of the carbon substrate and the scratch value of the TaC coating on the carbon substrate, the surface scratch value of the TaC coating having the carbon substrate was a variable Correlation of linear functions. This correlation is shown in the above-mentioned mathematical expression 2. In addition, for Examples 1 to 3 described above, the surface of the TaC coating layer was photographed using a scanning electron microscope (SEM). In this test, the area and number of cracks generated after applying pressure to the surfaces of the TaC coatings of Examples 1 to 3 were observed.

FIG. 4a is a scanning electron microscope (SEM) analysis photograph of the TaC coating surface of the high-hardness TaC coating carbon material prepared according to the above Example 1, and 4b is a diagram illustrating it. FIG. 5a is a scanning electron microscope (SEM) analysis photograph of the TaC coating surface of the high-hardness TaC coating carbon material prepared according to the above Example 2, and 5b is a diagram illustrating it. FIG. 6a is a scanning electron microscope (SEM) analysis photograph of the TaC coating surface of the high-hardness TaC coating carbon material prepared according to the above Example 3, and 6b is a diagram illustrating it.

Here, it was found that in Example 1 where the average porosity of the carbon substrate was 18.7 vol%, the average area of each sheet was the largest after the occurrence of cracks, and the example whose average porosity was 15.5 vol%. In 3, the average area of each sheet after the crack was generated was the smallest. From this, it can be found that the smaller the average porosity of the carbon substrate, the more cracks are generated.

110‧‧‧carbon substrate

120‧‧‧TaC coating

121‧‧‧ first coating

122‧‧‧Second coating

123‧‧‧Third coating

130‧‧‧ Impregnation area

131‧‧‧area

132‧‧‧First Zone

133‧‧‧second zone

FIG. 1 is a conceptual cross-sectional view illustrating a pore-containing carbon substrate provided in an embodiment of the present invention. 2 is a conceptual cross-sectional view illustrating a high-hardness TaC-coated carbon material according to an embodiment of the present invention, which includes a carbon substrate and a TaC coating formed on the carbon substrate. FIG. 3 is a conceptual cross-sectional view illustrating a high-hardness TaC-coated carbon material according to another embodiment of the present invention, including a carbon substrate and a plurality of TaC coatings on which a plurality of layers are formed. FIG. 4a is a scanning electron microscope SEM analysis photograph of a TaC coating surface of a high-hardness TaC coating carbon material prepared according to the following Example 1, and 4b is a diagram illustrating it. 5a is a scanning electron microscope SEM analysis photograph of a TaC coating surface of a high-hardness TaC coating carbon material prepared according to Example 2 below, and 5b is a diagram illustrating the same. 6a is a scanning electron microscope SEM analysis photograph of a TaC coating surface of a high-hardness TaC coating carbon material prepared according to the following Example 3, and 6b is a diagram illustrating the same.

Claims (9)

A high-hardness TaC-coated carbon material includes: a carbon substrate; and a TaC coating formed on the carbon substrate, and a TaC content in a region from a surface depth of the carbon substrate of 80 μm to 150 μm is 15 vol% -20vol%. The high-hardness TaC-coated carbon material according to claim 1, wherein a TaC content from a region having a depth of 40 μm to 75 μm from the surface of the carbon substrate is 16 vol% to 20 vol%, and a depth from the surface of the carbon substrate The TaC content in the region of 75 μm to 150 μm is 13 vol% to 18 vol%. The high-hardness TaC coating carbon material according to claim 1, wherein a surface scratch value of the TaC coating is 3.5N or more. The high-hardness TaC-coated carbon material according to claim 1, wherein the surface scratch value of the TaC coating is obtained by the following mathematical formula 1, [Mathematical formula 1] The surface scratch value (N) = from the The TaC content (vol%) x (1.4 to 1.6) -19.5 in the region where the carbon substrate has a surface depth of 80 μm to 150 μm. A method for preparing a high-hardness TaC-coated carbon material includes the following steps: preparing a carbon substrate having an average porosity of 15 vol% to 20 vol%; and forming a TaC coating on a surface of the carbon substrate. The method for preparing a high-hardness TaC-coated carbon material according to claim 5, wherein the step of forming the TaC coating is to immerse TaC in the pores of the carbon substrate, and inside the carbon substrate A TaC impregnated region is formed in contact with the TaC coating. The method for preparing a high-hardness TaC coated carbon material according to claim 5, wherein the step of preparing the carbon substrate is to prepare the required A carbon substrate having the average porosity at the surface scratch value, [Mathematical formula 2] The average porosity (vol%) of the carbon substrate = (surface scratch value N + 19.5) x (0.65 to 0.7). The method for preparing a high-hardness TaC-coated carbon material according to claim 5, wherein the step of forming the TaC coating is performed at 1900 degrees Celsius to 2500 degrees Celsius using chemical vapor deposition (CVD). The method for preparing a high-hardness TaC coating carbon material according to claim 5, wherein the step of forming the TaC coating is performed multiple times to form a plurality of TaC coatings.