JP2007321194A - Corrosion resistant thermal spray coating and sealing/covering method for thermal spray coating - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique capable of solving the defect in a thermal spray coating that seawater components, acid, alkali or the like infiltrate inside through pierced pores and opened pores, and corrode a base material, thus making the coating easily peel. <P>SOLUTION: In the corrosion resistant thermal spray coating, the opened pore parts in a thermal spray coating are filled with amorphous hydrocarbon solid matter comprising 10 to 45 atomic% hydrogen, and also, the surface of the thermal spray coating is coated with an amorphous hydrocarbon solid matter coating with a coating thickness of 0.5 to 80 μm. By the high hydrogen-containing amorphous hydrocarbon solid matter, the pores in the thermal spray coating are sealed, and coating formation to the surface of the coating is performed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a corrosion-resistant thermal spray coating and a method for sealing a thermal spray coating, and in particular, a method for sealing treatment and a protective coating forming process for imparting corrosion resistance to the surface of a thermal spray coating having open pores, and this The present invention relates to a corrosion-resistant sprayed coating obtained by using the technology.

In the thermal spraying method, metal, ceramic, cermet and other powders were melted by the plasma flame or flammable gas combustion flame, and then sprayed at high speed toward the surface of the sprayed body (base material) to melt the surface. This is a surface treatment technique in which particles are deposited and formed into a film (thickening) to form a thermal spray coating member. The thermal spray coating formed by such a process is deposited and formed in a state in which most of the particles constituting the coating are flattened, but when observed microscopically, it is inevitable between the particles. There are voids, which become the pores of the sprayed coating and cause many obstacles. In particular, it is known that various ceramic sprayed coatings having a high melting point have many open pores. Therefore, the development goal of conventional thermal spraying technology is
(1) Effectively utilizing a high-temperature heat source to completely melt the sprayed particles to eliminate the increase in the mutual fusion area of the particles and the generation of unmelted particles,
(2) By adding a large kinetic energy to the thermal spray heat source, applying a large acceleration force to the sprayed particles that fly through it, and generating a strong collision energy on the surface of the sprayed object, the mutual bonding area of the particles is increased. Letting
Etc.

  With respect to this point, in Patent Document 1, conventionally, by performing low-pressure plasma spraying in an argon atmosphere of 50 to 200 hPa, the bonding force between the sprayed particles is increased, or the surface of the metal particles that is one of the causes of pore generation is applied. A method of reducing the generated oxide film has been proposed. In recent years, due to such technological development, the porosity of the thermal spray coating tends to decrease, but the pores have not yet been completely eliminated. Especially for oxide ceramics that have a high melting point and are not affected by air (oxygen) in the atmosphere, the effect of reduced-pressure plasma spraying is very small, and the porosity reduction has still room for improvement compared to metal spray coatings. there were.

  Under the assumption that pores are unavoidably present in the thermal spray coating in such a situation, a measure for sealing treatment after film formation is encouraged. For example, the JIS-H9302 ceramic spraying work standard describes a method in which an inorganic and organic polymer sealing agent is applied to the surface after forming a ceramic sprayed coating.

Further, there are the following proposals for the method and sealing agent for sealing the pores of the thermal spray coating.
(1) Patent Documents 2 to 4 disclose methods of sealing using an organic polymer material such as silicone having a corrosion resistance, a silicon compound such as ethyl silicate, and a synthetic resin.
(2) In Patent Documents 5 and 6, a thermal spray coating is immersed in an electrolytic solution containing a metal alkoxide or a metal oxide, then electrolyzed, and the solute component or oxidation is introduced into the pores using the principle of electrophoresis. A method of filling and sealing an object is disclosed.
(3) Patent Document 7 discloses a technique in which an organic polymer agent that is cured by visible light is applied to the surface of a thermal spray coating, the pores are filled and sealed, and cured by natural light.
(4) Patent Document 8 discloses a technique in which a sealing agent is applied to the surface of a sprayed coating and then sealed by melting the coating particles by irradiating the surface with a laser.
Japanese Patent Laid-Open No. 1-139749 Japanese Patent Laid-Open No. 54-32422 JP-A-57-70275 JP-A 64-62453 JP-A-62-260096 JP 7-41927 A JP-A-5-106014 JP-A-10-306363

The object of the present invention is to compensate for the drawbacks of the prior art for sealing pores in a sprayed coating and to modify the coating so that the excellent physicochemical functions of the sprayed coating are not hindered. Is to propose. That is, the present invention is a technique for solving the following problems of the prior art.
(1) In the technique using a silicon-based sealing agent, the pores cannot be completely sealed, and the sealing effect is lost because the silicon compound is eluted in the alkaline aqueous solution.
(2) Organic polymer-based pore sealants can withstand acid, alkali, etc., but are easily affected by temperature. Especially, polymer-based sealants are softened or decomposed at 150 to 180 ° C. First, it cannot withstand long-term use in a high temperature environment of 200 ° C. or higher.
(3) Sealing technology using electrophoretic phenomenon makes it difficult to process large thermal sprayed coatings, and only the electrolyte enters the fine pores where electrophoretic action does not work. Becomes incomplete and causes red rust.
(4) The technology of melting and sealing the surface of the thermal spray coating with a laser requires expensive equipment, and when the molten thermal spray coating solidifies, it causes volume shrinkage and generates fine cracks. There is.

As a result of diligent research to achieve the above object, the inventors have developed a corrosion-resistant sprayed coating and a sealing coating method according to the following gist configuration.
That is, according to the first aspect of the present invention, the open pore portion of the thermal spray coating is filled with an amorphous carbon hydrogen solid containing 10 to 45 atomic% of hydrogen, and 0.5 to 0.5 on the thermal spray coating surface. This is a proposal of a corrosion-resistant sprayed coating characterized by being coated with an amorphous carbon hydrogen solid film having a thickness of 80 μm.

  In this corrosion resistant thermal spray coating, the amorphous carbon hydrogen solid layer is composed of fine solid particles having a carbon content of 90 to 55 atomic% and a hydrogen content of 10 to 45 atomic%, and a hardness (Hv) of 700 to 2800. It is preferable that the thermal spray coating material is one or more selected from metals, cermets and ceramics. In addition, the thermal spray coating may be formed by forming a secondary recrystallized layer generated by performing high energy irradiation treatment such as electron beam irradiation treatment or laser irradiation treatment on the surface.

  Further, the second one of the present invention is to hold the treatment sprayed coating in the exhausted reaction vessel and introduce a hydrocarbon-based gas, and apply high frequency power and a high voltage pulse to the sprayed coating, By generating plasma of the introduced hydrocarbon gas and holding the sprayed coating at a negative potential, 10 to 45 atomic% hydrogen is contained in the open pores of the sprayed coating and on the surface thereof. The present invention proposes a method for sealing and coating a thermal spray coating, which comprises adsorbing amorphous carbon hydrogen solids to seal open pores in the thermal spray coating and simultaneously coating the surface to form a coating.

  In the above method, the amorphous carbon hydrogen solid is composed of fine solid particles having a carbon content of 90 to 55 atomic% and a hydrogen content of 10 to 45 atomic%, and the film formed on the film is 0.5 It is preferable that the film thickness is ˜80 μm, and the amorphous carbon hydrogen solid and the film thereof have a characteristic of hardness Hv: 700 to 2800. Moreover, it is preferable to use what has the secondary recrystallization layer produced | generated by performing the high energy irradiation process, such as an electron beam irradiation process or a laser irradiation process, on the surface as the said thermal spray coating.

  According to the present invention, since the sprayed coating to be treated is set to a negative potential, the hydrocarbon-based gas component that is positively charged and ionized into a radical state is electrochemically attracted to the surface of the sprayed coating. The coating is uniformly formed not only on the fine open pores of the thermal spray coating but also on the hidden portion of the coating member having a complicated shape.

  According to the present invention, amorphous fine solid particles mainly composed of carbon and hydrogen are generated on the surface of the thermal spray coating, and this is filled in the open pores of the thermal spray coating, while the entire surface of the coating is formed. Also, the cause of corrosion damage due to the presence of pores, which was the greatest drawback of the thermal spray coating, can be solved.

  According to the present invention, the amorphous carbon hydrogen solid film has a compactness and an appropriate ductility, and is chemically stable, and is not affected by seawater, acid, alkali, or organic solvent. In addition, since it has an appropriate hardness and has good adhesion to the thermal spray coating, it is possible to provide a thermal spray coating with excellent corrosion resistance that does not cause contact scratches or peeling even during transportation.

  Further, according to the present invention, the amorphous carbon-hydrogen solid film can be formed almost uniformly without being affected by the shape of the member.

  Furthermore, the thermal spray coatings of metals, ceramics, cermets and the like coated with the amorphous carbon hydrogen solid film according to the present invention can exhibit the characteristics and functions of the respective thermal spray coating materials as they are, and this thermal spraying. It is possible to improve the life of the member coated with the coating and to greatly contribute to the expansion of the application field of the thermal spray coating.

  Hereinafter, a method for forming an amorphous carbon hydrogen solid film mainly composed of carbon and hydrogen on the surface of the thermal spray coating, filling the pores of the thermal spray coating, sealing, and further forming the coating is first described. explain.

  Thermal spray coatings suitable for forming the amorphous carbon hydrogen solid film include metals (including alloys), ceramics (oxides, silicides, nitrides, borides, and mixtures thereof), and cermets ( The base material formed by coating these spray coatings may be metal (including alloys) materials or non-metallic materials such as plastics and glass. Applicable.

  The thermal spray coatings targeted by the present invention include various types such as electric arc spraying, flame spraying, high-speed flame spraying, atmospheric plasma spraying, reduced pressure plasma spraying, water plasma spraying, explosion spraying, and cold spray spraying. All coatings formed by applying a thermal spraying method are targeted. In particular, it is effective for a sprayed coating formed of various ceramic spraying methods. The reason is that such a ceramic sprayed coating is more porous than the metal-based cermet sprayed coating, and the effects of the present invention are likely to appear. Of course, the present invention can also be applied to a film formed by the PVD method or the CVD method.

The sprayed coating to be applied may basically be as sprayed, or the surface of such a sprayed coating is mechanically ground and polished, or the surface of the sprayed coating is irradiated with an electron beam or laser. The film may be remelted to form a secondary recrystallized layer.
In the latter case, for example, a new layer, that is, a porous layer made of an oxide of the above-mentioned group IIIa element, is formed on the porous sprayed layer made of an oxide of the group IIIa element in such a manner that the portion of the outermost layer of the sprayed coating is altered. It is possible to form a secondary recrystallized layer obtained by secondary transformation of the material layer.

Generally, in the case of a metal oxide of a group IIIa element, for example, yttrium oxide (yttria: Y ₂ O ₃ ), the crystal structure is a cubic crystal belonging to the tetragonal system. When the yttrium oxide powder is plasma sprayed, when the molten particles collide and deposit on the surface of the substrate while being rapidly cooled while flying toward the substrate at high speed, the crystal structure becomes cubic ( A primary transformation is performed to a crystal form composed of a mixed crystal including monoclinic crystal in addition to Cubic. That is, the crystal type of the porous layer is composed of a crystal type composed of a mixed crystal including an orthorhombic system and a tetragonal system by performing a primary transformation by being super-cooled during thermal spraying. On the other hand, the secondary recrystallized layer is a layer in which the crystal type composed of the mixed crystal that has undergone primary transformation is secondarily transformed into a tetragonal crystal type.

  In this way, by subjecting the porous layer of the group IIIa oxide mainly composed of orthorhombic crystals that have undergone primary transformation to a high-energy irradiation treatment, at least the deposited sprayed particles of the porous layer are treated. By heating to the melting point or higher, this layer is transformed again (secondary transformation), and its crystal structure is returned to a tetragonal structure and crystallographically stabilized. In such a layer, during the primary transformation due to thermal spraying, the thermal strain and mechanical strain accumulated in the thermal spray particle deposition layer are released to stabilize the properties physically and chemically, and this layer accompanying melting. The formation of an amorphous carbon hydrogen solid layer on this layer can prevent the corrosive action of the environment in which it is used and exert the crystal-type characteristics of the particles that make up the thermal spray coating. It becomes possible.

  In addition to the above-described method, the thermal spray coating to be treated was previously formed with a metal ion or metal thin film having a strong chemical affinity with carbon such as Cr, Si, Ta, Nb, and Ti. Things are good too. That is, it is also effective to adsorb the amorphous carbon-hydrogen solid on the surface of the sprayed coating that has been subjected to such surface treatment.

  Next, an apparatus for forming the corrosion resistant sprayed coating according to the present invention will be described. FIG. 1 shows an apparatus (hereinafter referred to as “plasma CVD processing apparatus”) for filling the amorphous carbon hydrogen solid fine particles in the pores of the thermal spray coating and coating the surface thereof. This plasma CVD processing apparatus mainly includes a grounded reaction vessel 1, a to-be-processed sprayed coating 2 disposed at a predetermined position in the reaction vessel 1, and a conductor 3 connected thereto. A high voltage for applying a high voltage pulse in the reaction vessel 1 through a film forming organic gas introduction device (not shown), a vacuum device (not shown) for evacuating the reaction vessel, or the like. And a pulse generation power source 4.

  The plasma CVD processing apparatus is also provided with a plasma generating power source 5 for generating hydrocarbon-based gas plasma around the thermal spray coating 2 to be processed, as well as the conductor 3 and the thermal spray coating 2 to be processed. In order to apply both the high voltage pulse and the high frequency voltage at the same time, a superimposing device 6 is interposed between the high voltage pulse generating power source 4 and the plasma generating power source 5. The gas introduction device and the vacuum device are connected to the reaction vessel 1 via valves 7 a and 7 b, respectively, and the conductor 3 is connected to the superposition device 6 via a high voltage introduction unit 9.

  In order to adsorb amorphous carbon hydrogen solids in the pores and the coating surface of the sprayed coating to be treated using the above apparatus, the sprayed coating 2 to be treated is placed at a predetermined position in the reaction vessel 1, and a vacuum apparatus is installed. After operating and exhausting the air in the reaction vessel 1 for deaeration, an organic gas is introduced into the reaction vessel 1 by a gas introduction device. Next, high frequency power from the plasma generating power source 5 is applied to the thermal spray coating 2 to be processed. Since the reaction vessel 1 is in an electrically neutral state by the ground wire 8, the sprayed coating 2 to be treated has a relatively negative potential. For this reason, the positive ions in the plasma of the introduced gas generated by the application are generated around the negatively charged thermal spray coating 2 to be treated.

  Then, when a high voltage pulse (negative high voltage pulse) from the high voltage pulse generation power source 4 is applied to the thermal spray coating 2 to be treated, positive ions in the hydrocarbon gas plasma are attracted to the surface of the thermal spray coating 2 to be treated. Adsorbed. By such treatment, the pores and the coating surface of the sprayed coating 2 to be treated are filled with fine particles of amorphous carbon hydrogen solids, and grow on the surface into a film to form a protective film. That is, in the reaction vessel 1, finally, an amorphous carbon-hydrogen solid mainly composed of carbon and hydrogen is vapor-deposited around the thermal spray coating 2 to be treated, and simultaneously enters the pores of the coating, It is considered that the film is formed so as to cover the surface of the film.

That is, it is considered that the process of forming the amorphous carbon hydrogen solid layer on the thermal spray coating by the plasma CVD processing apparatus is performed through the following (a) to (d).
(A) Ionization of the introduced hydrocarbon gas (active neutral particles called radicals also exist) occurs.
(B) Ions and radicals changed from the hydrocarbon-based gas collide impactively with the surface of the object to be treated to which a negative voltage is applied.
(C) C—H having a low binding energy is cut by the energy at the time of collision, and then activated C and H are polymerized by repeating the polymerization reaction to form an amorphous state mainly composed of carbon and hydrogen. The carbon hydrogen solids are vapor deposited.
(D) When the reaction (c) occurs in the pores of the thermal spray coating to be treated, the pores are filled with fine solid particles of amorphous carbon hydrogen solids, while the surface of the coating is amorphous carbon hydrogen. A film composed of a solid deposition layer is formed.

In the above apparatus shown in FIG. 1, by changing the output voltage of the high voltage pulse generating power source 4 as shown in the following (a) to (d), ions such as metals are implanted into the thermal spray coating 2 to be treated. Is also possible.
(A) When ion implantation is focused on: 10 to 40 kV
(B) When performing both ion implantation and film formation: 5 to 20 kV
(C) When only film formation is performed: several hundred V to several kV
(D) When focused on sputtering, etc .: several hundred V to several kV

  The high voltage pulse generating power source 4 can repeatedly generate one or more pulses with a pulse width of 1 μsec to 10 msec. Further, the output frequency of the high frequency power of the plasma generating power source 5 can be changed in the range of several tens of kHz to several GHz.

As the organic gas introduced into the reaction vessel 1 of this apparatus, a hydrocarbon gas composed of carbon and hydrogen and a gas added with B, Si, O, Cl or the like are used.
(I) Gas phase state at room temperature (18 ° C.) CH ₄ , CH ₂ CH ₂ , C ₂ H ₂ , CH ₃ CH ₂ CH ₃ , CH ₃ CH ₂ CH ₂ CH ₃
(B) Liquid phase at normal temperature C ₆ H ₅ CH ₃ , C ₆ H ₅ CH ₂ CH, C ₆ H ₄ (CH ₃ ) ₂ , CH ₃ (CH ₂ ) ₄ CH ₃ , C ₆ H ₁₂ , C ₆ H ₅ Cl
(C) Organic Si compound (liquid phase)
(C ₂ H ₅ O) ₄ Si, (CH ₃ O) ₄ Si, [(CH ₃ ) ₄ Si] ₂ O

  The gas introduced into the reaction vessel in the gas phase at normal temperature can be introduced into the reaction vessel as it is, but the compound in the liquid phase is heated to gasify the gas ( Steam) is introduced into the reaction vessel. When an amorphous solid film is formed using an organic Si compound, Si may be mixed into the film, but Si strongly binds to carbon, and the surface of the amorphous carbon hydrogen solid is hydrophilic to hydrophilic. Although it changes to sex, there is no particular problem.

Next, the sealing method of the sprayed coating and the method of forming the amorphous carbon hydrogen solid coating on the surface thereof will be described in more detail using the above plasma CVD processing apparatus.
In the present invention, as described above, the layer formed on the surface of the thermal spray coating by the intrusion and deposition of the amorphous carbon hydrogen solids is applied with a high frequency voltage and a high voltage pulse in a superimposed manner under the generation of a hydrocarbon-based gas plasma. Then, by protecting the thermal spray coating as a member to be treated at a negative potential, the amorphous fine solid particles mainly composed of carbon and hydrogen deposited in a vapor phase in this atmosphere are attracted and adsorbed on the surface of the substrate. Formed by. In such a film forming environment, the hydrocarbon-based gas as the film forming material source is easily decomposed by the plasma and generates active carbon and hydrogen ions and radicals, which are generated in the surface layer pores of the sprayed coating. In addition to intruding, the surface is coated with a certain thickness. For example, the amorphous fine solid particles intrude into the open pores on the surface portion of the thermal spray coating and tightly infiltrate, or deposit on the surface to form a film having a certain thickness.

  In the plasma CVD process, low molecular weight hydrocarbons decomposed and generated by plasma of hydrocarbon gas, carbon and hydrogen ions and radicals are generated so as to cover the entire base material in the gas phase state, and these Is attracted and adsorbed on the surface of the thermal spray coating, and on the one hand, it penetrates into the open pores and fills and closes the pores. Accompanying this, it gradually accumulates on the surface of the film other than the open pores to cover the entire surface of the film. According to the experiments by the inventors, the film thickness at this time can be formed to a thickness of about 80 μm.

  In the plasma CVD process in which the high-frequency voltage and the high-voltage pulse are superposed, the thermal spray coating 2 to be processed is in a state where a negative potential (negative voltage) is applied in the reaction vessel 1, and therefore, The positively charged hydrocarbon gas ions and radicals excited by the plasma are generated in a cloud-like or mist-like manner so as to cover the entire surface of the thermal spray coating 2 to be treated. The fine solid particles are repeatedly adsorbed by discharge deposition. Therefore, even if the shape of the thermal spray coating 2 is complicated, the sealing and covering are relatively uniform. For example, even if the sprayed coating to be processed has a T-shape as shown in FIG. 2, the amorphous carbon hydrogen solids are adsorbed only on the necessary parts (the parts having no negative potential are adsorbed). Action does not occur). As described above, the method of the present invention is characterized in that both the sealing and the film formation can be performed by setting the sprayed coating to be treated to a negative potential, and that any portion can be formed evenly.

  In this regard, when a plasma discharge of a hydrocarbon gas is simply performed without applying a negative potential, the thickness of the film made of the amorphous carbon hydrogen solid formed is not uniform. The reason is that in the case of only plasma energy, the gas decomposition efficiency changes depending on the hydrocarbon gas concentration, and the gas concentration itself also changes depending on the shape and position of the T-shaped sample.

Further, in the plasma CVD process in which the high-frequency voltage and the high-voltage pulse of the present invention are superimposed, a layer made of amorphous carbon hydrogen solid produced using a hydrocarbon-based gas as a film forming raw material is made hydrophobic. Can do. As a result, even when the sprayed coating to be treated may come into contact with a corrosive aqueous solution during use, the wettability with the aqueous solution can be reduced and the surface can be finished where the corrosion reaction is difficult to occur. It becomes like this. On the other hand, when the lipophilic amorphous carbon hydrogen solid is formed or after the film is formed using a gas containing N ₂ or Si in the atmospheric gas, the hydrophilic property can be changed. Therefore, the amorphous carbon hydrogen solid film formed in the present invention can be appropriately changed according to the interface characteristics.

  In this amorphous carbon hydrogen solid layer, the carbon and hydrogen contents of this layer can be controlled by changing the type of hydrocarbon-based gas for film formation. For example, the larger the C / H ratio of the hydrocarbon gas component, the higher the carbon content in the formed amorphous carbon hydrogen solid layer. However, in this case, since the resulting layer has a high hardness and a high electrical resistivity, the wear resistance is improved, but the ductility is poor and the internal stress is large, so that it is difficult to form a thick film. In addition to this, a large number of micropores are likely to occur. Therefore, although the film itself made of amorphous carbon hydrogen solids is excellent in corrosion resistance, the corrosive component of the environment penetrates from these micropores and reaches the substrate surface to corrode it, thereby promoting the peeling of the film. There is a problem. In order to overcome such a problem, in the present invention, the carbon content of the amorphous carbon-hydrogen solid layer is set to be less than 90 atomic%.

  Therefore, in the present invention, the hydrogen content of the amorphous carbon hydrogen solid is 10 atomic% or more. This is because a higher hydrogen content is advantageous from the viewpoint of improving resistance to thermal and mechanical bending deformation and corrosion resistance of the amorphous carbon hydrogen solid layer. However, if the hydrogen content exceeds 45 atomic%, the carbon content is relatively low, which is not preferable in that the film is soft and wear resistance is lowered, and film formation becomes difficult.

That is, in the present invention, bending deformation of the substrate is reduced by reducing the C / H ratio in the hydrocarbon-based gas for film formation, that is, by increasing the hydrogen content in the amorphous carbon-hydrogen solid layer. As a result, the generated film is less likely to peel off. As described above, the amorphous carbon hydrogen solid film having an increased hydrogen content exhibits a characteristic with a hardness Hv of 700 to 2800, which can be said to be an extremely low physical property value as compared with general DLC. It is. In addition, since the internal stress value of the obtained film is small, it is possible to form an amorphous carbon hydrogen solid layer having a maximum film thickness of 80 μm.
For these reasons, the amorphous carbon hydrogen solid layer has a carbon content of 90 to 55 atomic% and a hydrogen content of 10 to 45 atomic%. Preferably, the carbon content is 85 to 62 atom% and the hydrogen content is 15 to 38 atom%.

The characteristics of the amorphous carbon hydrogen solid layer, which is the most characteristic configuration in the present invention, are summarized as follows.
(A) The main component of the amorphous carbon-hydrogen solid is composed of carbon and hydrogen. Therefore, it is not affected by seawater, various acids, alkalis and organic solvents, and is chemically stable.
(B) Aggregates of amorphous micro solid particles of carbon and hydrogen (nano-order ultra fine particles having a size of about 1 × 10 ⁻⁹ m or less) generated by plasma activated decomposition reaction of hydrocarbon-based gas are Since each particle and the particle deposition layer are in an amorphous state, there is no grain boundary that is prone to defects, a dense and excellent adhesion, and no peeling from the substrate.
(C) The layer (film) of the amorphous carbon hydrogen solid material is smooth (Ra: 0.5 μm or less) and excellent in wear resistance under sliding and rotating conditions (friction coefficient μ: 0.11-0. 2) Therefore, it is difficult for foreign matter to adhere.
(D) The amorphous carbon hydrogen solid layer is made oleophilic (hydrophobic) by a method such as coexistence of N ₂ or Si in a hydrocarbon gas during film formation or by injecting Si into the surface after film formation. ), Because it can be controlled to be hydrophilic, it can be developed in industrial fields where interface characteristics are regarded as important.
(E) It is known that the surface of a member for a semiconductor processing apparatus is destroyed when subjected to a plasma etching action in a halogen gas environment, but the amorphous carbon-hydrogen solid layer of the present invention, particularly the hydrogen content In a layer having a large content of 15 to 45 atomic%, when O ₂ is contained in the atmosphere, particularly when it is decomposed, it becomes a gas such as C _m H _n , CO, CO ₂ , H ₂ , and H ₂ O. Many particles of environmental pollution are hard to be generated.

  FIG. 3 shows a cross section of a thermal spray coating material in which amorphous carbon hydrogen solids are adsorbed by the above-described method of the present invention, pores of the thermal spray coating to be treated are sealed, and a coating is formed on the coating surface. FIG. 3A shows a structure in which a metallic sprayed coating 32 is formed on the surface of the base material 31 and then an amorphous carbon hydrogen solid film 34 is coated. FIG. FIG. 3C shows an example in which an amorphous carbon hydrogen solid film 33 is coated on the ceramic sprayed coating 33 after forming the ceramic sprayed coating 33. FIG. 3C shows a metallic sprayed coating 32 (undercoat) on the substrate 1. An example is shown in which an amorphous carbon hydrogen solid film 34 is coated on a ceramic sprayed film 33 formed as a top coat.

  FIG. 4 shows a cross section of a member in which the surface of a ceramic sprayed coating 42 formed on a substrate 41 is coated with an amorphous carbon hydrogen solid film 45. The ceramic sprayed coating 42 formed on the substrate 41 has through-holes 43 and open pores 44 that are open but do not reach the substrate, and the sealed voids 46 are also included in the coating. is there. When the amorphous carbon hydrogen solid film 45 is coated on the ceramic spray coating 42, the amorphous carbon hydrogen solid is deposited and filled in the through-holes 43 and the open pores 44 at the beginning of the treatment, The entire surface of the ceramic sprayed coating 42 is covered with the amorphous carbon hydrogen solid film 45.

Example 1
In this example, in order to investigate the basic anticorrosion performance of the amorphous carbon hydrogen solid film, the amorphous carbon hydrogen solid was formed with a film thickness of 0.5 to 50 μm directly on the substrate. In addition, as a corrosive environment, (a) high humidity, (b) salt spray, (c) 5% H ₂ SO ₄ , (d) 5% NaOH, etc., exposed to an atmosphere with different corrosion characteristics to investigate corrosion resistance. did.
(1) Base material and test piece As a base material, the following 2 types were used, and the test piece of width 30x length 50mm x thickness 2mm was produced from each.
(A) SS400 steel (b) Al (JIS-H4000 regulation No. 1070)
(2) Formation and Thickness of Film Using the apparatus shown in FIG. 1, an amorphous carbon hydrogen solid film having a thickness of 0.5 to 50 μm was formed on the entire surface of the test piece (hydrogen content 13 to 22). atom%).
(3) Corrosion test The corrosion test was performed under the following conditions.
(A) High humidity atmosphere: The test piece was exposed to an atmosphere of 30 ° C. and 90% relative humidity using a constant temperature and humidity chamber (200 hours).
(B) Salt spray: A 96-hour test was conducted by the salt spray test method defined in JIS-Z2371.
(C) 5% H ₂ SO ₄ immersion: It was immersed in a 5% H ₂ SO ₄ aqueous solution (20 to 25 ° C.) for 100 hours.
(D) 5% NaOH immersion: It was immersed in a 5% NaOH aqueous solution (30 to 35 ° C.) for 100 hours.
(4) Evaluation method The corrosion test results were evaluated by visual observation of the change in the surface of the test piece and the color tone of the H ₂ SO ₄ and NaOH aqueous solution before and after the test. In addition, as a test piece for comparison, untreated SS400 steel and Al were subjected to a corrosion test under the same conditions.
(5) Corrosion test results Table 1 shows the corrosion test results. As is clear from this result, the untreated SS400 steel specimens generated red rust or dissolved (No. 5) in all test atmospheres (No. 1, 3, 5) except 5% NaCl immersion. . Moreover, in the Al non-processed test piece (No. 2, 4, 6, 8), while generating white rust (No. 4) under conditions other than in a high-humidity atmosphere, the acid (No. 6) and alkali Also dissolved while generating hydrogen gas.

  On the other hand, a test piece in which an amorphous carbon hydrogen solid film is formed on a substrate exhibits excellent corrosion resistance regardless of the type of the substrate, and sufficient corrosion resistance in all corrosive environments with a film thickness of 1 μm or more. Showed resistance. However, when the film thickness was 0.5 μm, generation of red rust could be suppressed in a high humidity atmosphere and immersion in an alkaline solution, but slight rust and white rust were observed in salt spray and sulfuric acid immersion.

  From the above results, it was found that the effective anticorrosive action of the amorphous carbon hydrogen solid film was recognized in the film thickness range of 0.5 to 50 μm, particularly in the range of 1 to 50 μm.

(Example 2)
In this example, after forming an oxide-based ceramic sprayed coating directly on the surface of the substrate, the surface of the solid was coated with an amorphous carbon hydrogen solid film, and subjected to a salt spray test to investigate its corrosion resistance. did.
(1) Base material and test piece (numerical value is mass%)
SS400 steel (dimensions: width 50mm x length 70mm x thickness 3.2mm)
(2) Types of sprayed coating and spraying method The following oxide ceramics (a) to (f) were directly formed on the surface of the test piece to a thickness of 70 μm by the atmospheric plasma spraying method. The reason why the ceramic sprayed coating is applied to be thin is to discriminate the sealing-coating effect of the amorphous carbon hydrogen solid film by a short test.
_{(A) Al 2 O 3,} (b) Cr 2 O 3, (c) 8% Y 2 O 3 · 92% ZrO 2, (d) Al 2 O 3 · MgO _{Subineru, (e) 98% Al 2} O _{3 · 2% TiO 2, (} f) Y 2 O 3
(3) Formation and thickness of amorphous film Using the same apparatus as in Example 1, the film was formed to a film thickness of 5 μm (hydrogen content: 16 to 36 atomic%).
(4) Corrosion test conditions A 96-hour corrosion test was conducted by the salt water injection test method defined in JIS-Z2371.
(5) Evaluation method The evaluation of the corrosion test was determined by the presence or absence of red rust on the surface of the oxide ceramic before and after the test. As a comparative example, a thermal spray coating that does not cover the amorphous carbon hydrogen solid film was tested under the same conditions.
(6) Test results Table 2 shows the results of the corrosion test. As is apparent from this result, red rust was observed in all of the untreated sprayed coatings (No. 2, 4, 6, 8, 10, 12). That is, it is considered that salt water infiltrated from the pores of the ceramic sprayed coating to corrode the base material of SS400 steel, and the eluted iron ions floated on the coating surface to generate red rust. On the other hand, the test pieces (No. 1, 3, 5, 7, 9, 11) coated with the amorphous carbon hydrogen solid film have good sealing property and covering performance for any ceramic film. The occurrence of red rust was not observed.

(Example 3)
In this example, the effect of the sealing and covering of the amorphous carbon hydrogen solid film on the metal-based sprayed coating formed on the surface of the substrate was investigated.
(1) Substrate and test method Same as Example 2 (2) Types of sprayed coating and spraying method (numbers are mass%)
The following metal-based material was used as the thermal spray coating and was formed to a thickness of 50 μm by various thermal spraying methods.
(A) 95% Ni-5% Al, SUS304 steel ... Flame spraying (b) Cr, Mo, 50% Ni-50% Cr alloy ... Air plasma spraying method (c) Ti ... Low pressure plasma spraying method (d ) Cu: Arc spraying method (3) Formation and thickness of amorphous carbon hydrogen solid film Same as Example 2 (hydrogen content 16-36 atomic%)
(4) Corrosion test Same as Example 2 (5) Evaluation method Same as Example 2 (6) Corrosion test results Table 3 shows the corrosion test results. As is clear from this result, the untreated metal-based sprayed coatings (No. 2, 4, 6, 8, 10, 12, 14, 16) all generated red rust in the salt spray environment. Since the metal of these thermal spray coatings shows an electrochemically noble potential compared to SS400 steel, it is considered that the corrosion was promoted by the base material serving as the anode by the salt water entering from the pores of the coating.
In contrast, the test pieces (No. 1, 3, 5, 7, 9, 11, 13 and 15) coated with the amorphous carbon hydrogen solid film showed no red rust and the intrusion of salt water. It is considered that corrosion of the base material [occurrence of red rust] was suppressed.

Example 4
In this example, the anticorrosive effect of an amorphous carbon-hydrogen solid film was investigated on a metal and carbide-based cermet sprayed coating electrochemically formed on an SS400 steel substrate. The type of base material, the size of the test piece, the formation method and film of the amorphous film, the corrosion test method, the evaluation method, and the like are the same as those in the previous examples.
(1) Types of thermal spray coating and thermal spraying method (numbers are mass%)
(A) Al, (b) 15% Zn-85% Al, (c) 5% Mg-95% Al, (d) 12% Co-88% WC, (e) 20% Ni-5% Cr-75 % Cr ₃ C ₂ , (f) 25% Ni-7% Cr-68% TiC
(A) to (c): Flame spraying, (d) to (f): High-speed flame spraying (2) Corrosion test Although a salt spray test was used as a corrosion test, in this example, Al and Zn exhibiting anticorrosive action -Since coatings such as Al and Mg-Al were used, the corrosion time was extended up to 1500 hours.
(3) Corrosion test results Table 4 shows the corrosion test results. As is clear from this result, the coating showing the anticorrosive action on the SS400 steel withstood the test for 96 hours even in the untreated state (No. 2, 4, 6), and no red rust was observed. . However, when the corrosion test reached 500 hours, red rust was generated locally, and especially at 1000 hours, red rust was observed. It is considered that most of the sprayed coating formed on these test pieces was consumed and the anticorrosive action was lost. On the other hand, no red rust was observed after 1500 hours in the test pieces (Nos. 1, 3, and 5) on which the amorphous carbon-hydrogen solid film was formed.
On the other hand, since the carbide cermet sprayed coating does not have an electrochemical anticorrosive action, red rust was generated on the entire surface by a 96-hour test in the untreated sprayed coating (No. 8, 10, 12). However, in the test pieces (Nos. 7, 9, and 11) in which an amorphous carbon hydrogen solid film was formed on this film, no abnormality was observed even after 1500 hours, and excellent corrosion resistance was exhibited.

(Example 5)
In this example, the sealing effect of a commercially available sealing agent for thermal spray coating and the amorphous carbon hydrogen solid film according to the present invention was compared.
(1) Base material and test piece Same as Example 3. (2) Type of sprayed coating and spraying method Al ₂ O ₃ was used as a coating material, and it was applied to a thickness of 120 μm by an atmospheric plasma spraying method.
(3) Kind of sealant The following sealant was processed with respect to the surface of a thermal spray coating.
(A) Amorphous film: 3 μm thick was constructed by the method described above (hydrogen content: 24-38 atomic%).
(B) Silicon-based sealing agent: A commercially available inorganic silicon oxide was formed to a thickness of 2 μm.
(C) Organic polymer sealant: A commercially available acrylic resin sealant was formed to a thickness of 5 μm.
(4) Corrosion test conditions In this example, it was necessary to dry or harden the inorganic and organic sealing agents at a temperature of 110 to 140 ° C. after the sealing treatment. The heat treatment was performed. Thereafter, all the test pieces after the sealing treatment were heated in the atmosphere at 210 ° C. for 3 hours to investigate the heat resistance of the sealing agent.
After these heat treatments, the corrosion resistance effect was examined by a salt spray test (96 hours).
(5) Corrosion test results Table 5 shows the corrosion test results. As is apparent from these results, a moderate anti-corrosion effect was observed even with a commercially available sealant under the condition that heating at 210 ° C. was not performed, and in particular, the organic sealant (No. 6) was completely abnormal in appearance. I couldn't. However, the effect of the inorganic sealing agent (No. 4) tended to have a weak anticorrosion effect compared to the organic type. However, in the organic sealing agent (No. 5), when heated at 210 ° C., the polymer film deteriorated, and many cracks were generated in the resin film, and the anticorrosion effect was completely lost. This tendency was also observed in inorganic sealants. On the other hand, the amorphous carbon hydrogen solid film (Nos. 1 and 2) exhibited a good sealing effect irrespective of the presence or absence of heating at 210 ° C., and no occurrence of red rust was observed.

(Example 6)
In this example, assuming that it is used in a corrosive atmosphere or an environment where organic solvents are handled, a metal-based undercoat is applied to an SS400 steel substrate, and an oxide ceramic sprayed coating is further formed. The anticorrosive effect of the amorphous carbon hydrogen solid film formed for such a composite film was investigated.
(1) Base material and test piece Same as Example 3.
(2) Types of thermal spray coating and thermal spraying method (numbers are mass%)
(A) Undercoat: 80% Ni-20% Cr (atmospheric plasma spraying method)
(B) _{Topcoat: Al 2 O 3, Y 2} O 3, 8% Y 2 O 3 -92% ZrO 2 ( atmospheric plasma spraying)
The film thickness is 50 μm for the undercoat and 150 μm for the topcoat.
(C) Formation method and film thickness of amorphous carbon-hydrogen solid film The film thickness was set to 5 μm by the same method as in Example 1 (hydrogen content: 15 to 24 atom%).
(4) Corrosion test (A) 5% HCl: A beaker containing a 5% HCl aqueous solution was maintained at 20 to 23 ° C., and a test piece was immersed therein to evaluate the corrosion resistance.
(B) 5% NaOH: The test piece was immersed in a beaker containing a 5% NaOH aqueous solution, and the alkali resistance was evaluated at a temperature of 20 to 23 ° C. for 24 hours.
(C) 95% toluene: The test piece was immersed in a 95% toluene solution for reagents (15 to 20 ° C.) for 24 hours to evaluate organic solvent resistance.
(5) Corrosion test results Table 6 shows the corrosion test results. As is apparent from the results, no red rust was generated in the 5% NaOH aqueous solution and no change in appearance was observed regardless of the presence of the undercoat and the amorphous carbon hydrogen solid film. However, in a 5% HCl aqueous solution, even if an undercoat is applied, the film (No. 2, 4, 6, 8, 10, 12) that is not coated with an amorphous carbon hydrogen solid film is a top coat. All were corroded regardless of the type, the color of the HCl aqueous solution changed from yellow to light yellow, and dissolution of the SS400 steel and the undercoat component of the base material was estimated. On the other hand, the color tone of the aqueous HCl solution in which the film (No. 1, 3, 5, 7, 9, 11) coated with the amorphous carbon hydrogen solid film is not changed, and the film maintains a healthy state. It was.

(Example 7)
In this example, in consideration of utilization as a semiconductor processing apparatus member, an oxide ceramic sprayed coating was directly formed on an Al base, and then the corrosion resistance in various halogen-based gases was investigated.
(1) Base Material and Test Specimen A test piece having an aluminum alloy (JIS-H4000) as a base material and dimensions: width 20 mm × length 30 m × thickness 2.3 mm was collected.
(2) spray coating type and thermal spraying the thermal spray coating _{types: Al 2 O 3, YAG (} Y 3 Al 5 O 12), Y 2 O 3
A sprayed coating having a thickness of 150 μm was directly formed on the alloy substrate by atmospheric plasma spraying.
(3) Formation method and film thickness of amorphous carbon hydrogen solid film The film thickness was set to 5 μm by the same method as in Example 1 (hydrogen content 22 to 35 atomic%).
(4) Corrosion test (a) Active halogen gas test; The apparatus shown in FIG. 5 was used for this test. In this test, the test piece 51 was allowed to stand on an installation table 56 inside a stainless steel tube 53 provided at the center of the electric furnace 52, and then a corrosive gas 54 was flowed from the left side. A microwave having an output of 600 W was added to the quartz discharge tube 55 provided in the middle of the piping to promote activation of the corrosive gas. Further, the activated corrosive gas was introduced into the electric furnace, and after the test piece 51 was corroded, it was discharged out of the system from the right side. In this test, a 10-hour corrosion test was performed while the test piece temperature was 180 ° C., the corrosive gas CF ₄ was flowed at 150 ml / min, and O ₂ was flowed at 75 ml / min.
(B) HCl vapor test: A 30% HCl aqueous solution is placed at the bottom of a desiccator for chemical experiments, and a glass porous plate is disposed thereon, and then a test piece is placed on the glass plate to allow HCl vapor. The specimen was corroded by HCl vapor rising from the hole in the glass plate. In addition, an untreated SS400 steel plate is such that front red rust is generated by a one-hour test.
(C) HF vapor test: After placing a test piece in a SUS316 autoclave having a capacity of 3 L, 500 ppm of HF gas was poured from the outside, and a corrosion test was performed at 150 ° C. for 24 hours.
(5) Corrosion test results Table 7 shows the corrosion test results. As is clear from this result, in the test pieces (Nos. 2, 4, and 6) that do not form the amorphous carbon hydrogen solid film, the ceramic spray coating itself shows relatively good corrosion resistance, but passes through the pores of the film. As a result, the base material was corroded by the corrosive gas that had penetrated into the interior, and the bonding strength with the ceramic film was lost. On the other hand, the test piece on which the amorphous carbon hydrogen solid film was formed showed sufficient corrosion resistance against all corrosive gases, and the film itself was dense, and no abnormality was observed in appearance.

(Example 8)
In this example, the surface of the oxide ceramic sprayed coating was irradiated with high energy such as an electron beam and a laser to investigate the anticorrosive effect of the amorphous film on the melted film forming particles on the coating surface.
(1) Base material and test piece Using SS400 steel, a test piece having a width of 20 mm, a length of 30 m, and a thickness of 3.2 mm was collected.
(2) Type of sprayed coating and spraying method Type of sprayed coating: Y ₂ O ₃ Atmospheric plasma spraying was used to form a film thickness of 80 μm.
(3) Types and conditions of high energy irradiation (a) Electron beam irradiation: Using an electron beam irradiation apparatus having the following specifications, a film surface depth of 3 μm was remelted.
Irradiation atmosphere: 1 × 10 ^{−1 to} 5 × 10 ⁻³ MPa
Irradiation output: 10-30KV
Irradiation speed: 1 to 20 mm / s
(B) Laser irradiation: 10 μm was remelted from the surface of the film using a laser irradiation apparatus having the following specifications.
Laser power: 2-4kW
Beam area: 5-10 mm ²
Beam scanning speed: 5 to 20 mm / s
(4) Formation of amorphous carbon-hydrogen solid film and film thickness Using the same apparatus as in Example 1, the film thickness is 3 μm (hydrogen content: 24-32 atomic%).
(5) Corrosion test (b) Salt spray test: 96 hours test conducted according to JIS-Z2371 (b) Active halogen gas test: conducted under the same conditions as in Example 7 (c) HCl vapor test: desiccator for chemical experiments A 30% aqueous HCl solution was placed at the bottom of the substrate, and a porous glass plate was placed on top of the solution, and then a test piece was left on the glass plate to conduct a corrosion test for 24 hours. In this environment, a large amount of HCl vapor was generated from an HCl solution having a high vapor pressure, and red rust was generated on the entire surface of SS400 steel after exposure for 1 hour.
(6) Corrosion test results Table 8 shows the corrosion test results. As is clear from this result, even when the Y ₂ O ₃ sprayed coating is irradiated with a beam and a laser, the coating (Nos. 2 and 6) as it is is observed to generate local red rust in all corrosion tests. Therefore, the intrusion of corrosive components could not be completely prevented. In order to elucidate the cause, when the surface of the sprayed coating irradiated with an electron beam and laser is observed with a magnifying glass, the pores peculiar to the sprayed coating have disappeared due to the melting phenomenon, but there are many small cracks. found. These cracks are considered to have penetrated into the inside through the thermal spray coating melted by high energy irradiation. Compared to the large amount of red rust generated in all corrosion tests in the films not subjected to high energy irradiation (No. 4, 8), the effect of high energy irradiation is recognized, but it is not a sufficient countermeasure. . On the other hand, in the films (Nos. 1, 3, 5, and 7) coated with the amorphous carbon hydrogen solid film, the intrusion of the corrosive component was completely prevented, and the occurrence of red rust was not observed at all.

  The technology of the present invention is used as a member for a semiconductor processing apparatus such as a deposition shield, a baffle plate, a focus ring, an insulator ring, a shield ring, a bellows cover, and an electrode. In addition, the present invention is also suitable as a surface treatment for conveying members such as Si thin films and Si thin film processed products, and can also be applied to plasma processing container inner members and parts such as liquid crystal devices. . Furthermore, the present invention is also effective as a technique for application to a mirror-coated thermal spray coating product, specifically, a printing roll, a film roll, and a photosensitive paper roll.

It is a basic diagram of a plasma CVD processing apparatus. It is a basic diagram which shows the example of having formed the amorphous carbon hydrogen solid film | membrane in the T-type sprayed-film test piece. It is sectional drawing which shows the example which formed the amorphous carbon hydrogen solid substance film | membrane in the thermal spray coating coating | coated member. It is a schematic diagram of the sealing and covering situation when an amorphous carbon hydrogen solid film is formed on the surface of a ceramic sprayed coating. It is a basic diagram of the corrosion test apparatus using the gas containing a halogen compound.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Reaction container 2 Thermal spray coating 3 Conductor 4 High voltage pulse generation power source 5 Plasma generation power source 6 Superimposing device 7a, 7b Valve 9 High voltage introduction part 21 Steel base material 22 Thermal spray coating 23 Amorphous carbon hydrogen solid film 31 Base material 32 Metallic spray coating 33 Ceramic spray coating 34 Amorphous carbon hydrogen solid film 41 Base material 42 Ceramic spray coating 43 Through-hole 44 Open pore 45 Amorphous carbon hydrogen solid film 46 Void 51 Test piece 52 Electric furnace 53 Stainless steel tube 54 Corrosive gas 55 Quartz discharge tube 56 Test specimen mounting base

Claims (8)

The open pores of the thermal spray coating are filled with an amorphous carbon hydrogen solid containing 10 to 45 atomic% of hydrogen, and the surface of the thermal spray coating has an amorphous carbon hydrogen solid with a thickness of 0.5 to 80 μm. A corrosion-resistant sprayed coating characterized by being coated with a film. The amorphous carbon hydrogen solid layer is composed of fine solid particles having a carbon content of 90 to 55 atomic% and a hydrogen content of 10 to 45 atomic%, and has a hardness (Hv) of 700 to 2800. The corrosion-resistant thermal spray coating according to claim 1. The corrosion-resistant thermal spray coating according to claim 1 or 2, wherein the thermal spray coating material is one or more selected from metals, cermets and ceramics. The said thermal spray coating has a secondary recrystallization layer produced | generated by giving a high energy irradiation process to the surface, The corrosion-resistant thermal spray coating of any one of Claims 1-3 characterized by the above-mentioned. Holds the sprayed coating to be treated and introduces a hydrocarbon gas into the evacuated reaction vessel, and applies high frequency power and high voltage pulses to the sprayed coating to generate plasma of the introduced hydrocarbon gas. At the same time, by holding the sprayed coating at a negative potential, the amorphous carbon-hydrogen solid containing 10 to 45 atomic% hydrogen is adsorbed in the open pores of the sprayed coating and on the surface thereof, A method for sealing and coating a sprayed coating, comprising sealing a surface of an open pore in a sprayed coating and simultaneously coating the surface thereof. The amorphous carbon hydrogen solid is composed of fine solid particles having a carbon content of 90 to 55 atomic% and a hydrogen content of 10 to 45 atomic%, and the coating film has a thickness of 0.5 to 80 μm. The sealing coating method of the thermal spray coating of Claim 5 characterized by the above-mentioned. The method for sealing and covering a sprayed coating according to claim 5 or 6, wherein the amorphous carbon hydrogen solid and the film thereof have a characteristic of hardness Hv: 700 to 2800. The said thermal spray coating uses what has a secondary recrystallized layer produced | generated by giving a high energy irradiation process to the surface, The sealing of the thermal spray coating of any one of Claims 5-7 characterized by the above-mentioned. Coating method.

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