JP6365969B2 - Thermal barrier coating material, turbine member having the same, and thermal barrier coating method - Google Patents

Description

  The present invention relates to a thermal barrier coating material, a turbine member having the thermal barrier coating material, and a thermal barrier coating method.

  In the gas turbine, in order to improve the efficiency, the temperature of the gas used is set high. A turbine member (a moving blade, a stationary blade, etc.) exposed to such a high-temperature gas is provided with a thermal barrier coating (TBC) on the surface thereof. The thermal barrier coating material is obtained by coating the surface of a turbine member, which is a sprayed material, with a thermal spray material having a low thermal conductivity (for example, a ceramic material having a low thermal conductivity) by thermal spraying. The heat and durability are improved.

  On the other hand, fuels used in gas turbines are diversified, and there is an increasing need for gas turbines using heavy oil as well as conventional gas turbines using gas. In such a heavy oil-fired gas turbine, there is a problem that the thermal barrier coating material is damaged in a short operation. Specifically, in the case of a heavy oil fired gas turbine, the turbine member is exposed to a molten salt containing sodium sulfate generated by sodium, sulfur, etc. contained in the heavy oil, so that the molten salt becomes a thermal barrier coating material. It is known that an event occurs that penetrates into the interior and peels off the thermal barrier coating material from the surface of the turbine member. Therefore, a thermal barrier coating material having high reliability is desired in an environment where molten salt is present.

  Such a thermal barrier coating material is disclosed in Patent Document 1, for example. The thermal barrier coating material described in Patent Document 1 forms an environmental shielding layer mainly composed of silica on the surface of the thermal barrier layer, which is a top coat layer, and prevents molten salt from coming into contact with the thermal barrier layer. . Specifically, an environmental shielding layer that prevents penetration of the molten salt is formed by applying and heating a ceramic adhesive on the surface of the heat shielding layer formed of stabilized zirconia.

  Further, in the thermal barrier coating material disclosed in Patent Document 2, a corrosion component permeation preventive layer is formed on the surface of the ceramic layer as the top coat layer to prevent permeation of corrosive components such as molten salt.

JP 2012-137073 A Japanese Patent No. 4388466

  However, the thermal barrier coating material as described above forms a layer that prevents the penetration of the molten salt on the surface of the topcoat layer. Therefore, there is a possibility that the layer that prevents the permeation of the molten salt may be peeled off due to foreign matters flying and contacting during operation of the gas turbine. In such a case, the penetration of the molten salt cannot be prevented, and a part of the thermal barrier coating material is peeled off, thereby impairing the thermal barrier property. That is, there is a possibility that the thermal barrier property of the thermal barrier coating material cannot be secured stably during operation of the gas turbine.

  The present invention has been made to solve the above problems, and provides a thermal barrier coating material capable of stably ensuring thermal barrier properties, a turbine member including the thermal barrier coating material, and a thermal barrier coating method. It is.

In order to solve the above problems, the present invention proposes the following means.
The thermal barrier coating material according to the first aspect of the present invention includes a bond coat layer as a metal bonding layer laminated on a base material, a top coat layer containing ceramic laminated on the bond coat layer, and A dense layer that is formed on the inner side of the surface in the top coat layer, is formed of the same material as the top coat layer, and has a lower porosity than the top coat layer, and the top coat layer includes both the inner and surface sides of the dense layer, Ru is formed of the same material and the same porosity.
Further, in the thermal barrier coating material according to another aspect of the present invention, the same porosity is a range in which the porosity of the top coat layer on the inner side and the surface side with respect to the dense layer is 8% to 15%, respectively. may it der that fall within the limits.

  According to such a configuration, a dense layer having a porosity smaller than that of the top coat layer is formed in the top coat layer, so that the penetration of the molten salt is prevented by the dense layer. That is, the dense layer can be formed without exposing the dense layer by not forming the dense layer on the surface of the topcoat layer. Therefore, the dense layer can be protected by a part of the top coat layer formed on the surface side. Thereby, even if it is a case where a foreign material flies and contacts, it can suppress that a dense layer is damaged, and it can suppress that a dense layer is damaged by foreign materials other than molten salt.

  In the thermal barrier coating material according to another aspect of the present invention, the dense layer may have a porosity of 1% or more and less than 4%.

  According to such a configuration, it is possible to suppress penetration of the molten salt into the top coat layer by forming a dense layer having a low porosity.

  Furthermore, in the thermal barrier coating material according to another aspect of the present invention, the dense layer may have a thickness in the range of 0.1 μm to 2 μm.

  According to such a configuration, since the film thickness is very thin, the uneven shape on the surface on the dense layer side in the top coat layer is hardly changed. Therefore, even when the dense layer is formed, the same interlayer strength as that when the dense layer is not formed can be maintained as the topcoat layer. Therefore, even if a dense layer is formed, the topcoat layer can be firmly bonded, and peeling at the boundary with different layers can be suppressed.

  Moreover, in the turbine member which concerns on the 2nd aspect of this invention, it has the said thermal barrier coating material on the surface.

  According to such a configuration, it is possible to form a highly reliable turbine member that can ensure heat insulation over a long period of time.

  The turbine according to the third aspect of the present invention includes the turbine member.

  According to such a structure, a turbine member becomes difficult to be damaged and a maintainability can be improved. Therefore, the operation stop time of the gas turbine for maintenance can be shortened.

Further, in the thermal barrier coating method according to the fourth aspect of the present invention, a bond coat layer laminating step for laminating a bond coat layer as a metal bonding layer on a base material, and after the bond coat layer laminating step, The same material as the first topcoat layer, which is implemented after the first topcoat layer laminating step of laminating the first topcoat layer containing ceramic on the bond coat layer, and the first topcoat layer laminating step A dense layer laminating step for forming a dense layer having a lower porosity than the first top coat layer, and a second top coat comprising ceramic on the dense layer, which is performed after the dense layer laminating step A second topcoat layer laminating step in which a layer is formed by laminating with the same material and the same spraying distance as the first topcoat layer.

  According to such a configuration, it is possible to form a thermal barrier coating material that can prevent the penetration of the molten salt by forming a dense layer having a porosity smaller than that of the topcoat layer in the topcoat layer.

  According to the present invention, the heat shielding property can be stably ensured by forming the dense layer in the top coat layer that prevents the penetration of the molten salt.

It is a schematic block diagram of the gas turbine which concerns on each embodiment of this invention. It is a schematic structure perspective view of a moving blade concerning each embodiment of the present invention. It is a principal part cross-sectional enlarged view of the moving blade which concerns on 1st embodiment of this invention. It is process drawing explaining the process of the thermal barrier coating method in 1st embodiment of this invention. It is the enlarged photograph explaining the thermal barrier coating material which the molten salt penetrate | infiltrated, Comprising: The same figure (a) is an enlarged photograph of the thermal barrier coating material before molten salt penetrate | infiltrated, The same figure (b) is the molten salt penetrated. It is an enlarged photograph of the thermal-insulation coating material in which the crack produced by this. It is a figure which shows the result of having analyzed the penetration | permeation degree of sulfur which is one of the components of the molten salt in a topcoat layer, Comprising: The same figure (a) is an analysis result in case a porosity is 10-12%, FIG. (B) shows the analysis result when the porosity is 5 to 8%. It is a principal part cross-sectional enlarged view of the moving blade which concerns on 2nd embodiment of this invention. It is an enlarged photograph explaining the dense layer in the Example of this invention.

<< first embodiment >>
Hereinafter, a first embodiment according to the present invention will be described with reference to FIGS.
As shown in FIG. 1, the gas turbine 1 of the present embodiment combusts by mixing a fuel with a compressor 2 that takes in a large amount of air and compresses it, and compressed air A compressed by the compressor 2. A combustor 3 to be converted, a turbine main body 4 that converts thermal energy of the combustion gas G introduced from the combustor 3 into rotational energy, and a part of the rotating power of the turbine main body 4 is transmitted to the compressor 2 to compress the compressor. And a rotor 5 for rotating the motor 2.

  The turbine body 4 generates power by converting the thermal energy of the combustion gas G into mechanical rotational energy by blowing the combustion gas G onto the rotor blades 7 provided in the rotor 5. The turbine body 4 is provided with a plurality of stationary blades 8 in a casing 6 of the turbine body 4 in addition to the plurality of rotor blades 7 on the rotor 5 side. In the turbine body 4, the moving blades 7 and the stationary blades 8 are alternately arranged in the axial direction of the rotor 5.

  As shown in FIG. 2, the turbine member in the present embodiment is a moving blade 7 of the turbine body 4. The moving blade 7 includes a moving blade main body 71 disposed in the combustion gas G flow path in the casing 6 of the turbine main body 4, a platform 72 provided at the base end of the moving blade main body 71, and the platform 72. A blade root 73 protruding to the opposite side of the moving blade body 71 and a shroud 74 provided at the tip of the moving blade body 71 are provided.

As shown in FIG. 3, the moving blade 7 has a base material 10 made of a heat-resistant alloy such as a Ni-based alloy, and a thermal barrier coating material 20 formed on the surface of the base material 10.
The thermal barrier coating material 20 includes a bond coat layer 21 laminated on the base material 10, a top coat layer 22 laminated on the surface of the bond coat layer 21, and the base material 10 in the top coat layer 22 rather than the surface thereof. And a dense layer 23 formed on the inner side.

  The bond coat layer 21 is formed as a metal bonding layer that suppresses the separation of the base material 10 and the top coat layer 22 and is excellent in corrosion resistance and oxidation resistance. The bond coat layer 21 is laminated, for example, by spraying a metal spray powder of MCrAlY alloy on the surface of the base material 10 as a spraying material. Here, “M” of the MCrAlY alloy constituting the bond coat layer 21 represents a metal element, for example, a single metal element such as NiCo, Ni, Co, or a combination of two or more thereof.

The top coat layer 22 is formed by spraying a thermal spray material containing ceramic on the surface of the bond coat layer 21. The topcoat layer 22 has a first topcoat layer 22a formed inside and a second topcoat layer 22b formed on the surface side with the dense layer 23 interposed therebetween. The first topcoat layer 22a and the second topcoat layer 22b in the present embodiment are formed using the same material and under the same conditions. The first top coat layer 22a and the second top coat layer 22b are preferably formed so that the porosity (occupancy ratio of the pores per unit volume) falls within the range of 8 to 15%, and particularly 10%. It is preferable. The thermal spray material used when forming the topcoat layer 22 is, for example, yttria-stabilized zirconia (YSZ) or ytterbium stabilized zirconia (ZrO ₂ ) partially stabilized with ytterbium oxide (Yb ₂ O ₃ ). Zirconia (YbSZ) is used.

The first top coat layer 22a only needs to be formed to have a thickness that can completely cover the bond coat layer 21. Specifically, the first topcoat layer 22a of the present embodiment is formed with a film thickness of about 200 μm.
The second topcoat layer 22b only needs to be formed to have a film thickness that can cover the dense layer 23 completely. Specifically, the second topcoat layer 22b of the present embodiment is formed with a film thickness of about 200 μm, like the first topcoat layer 22a.

  The dense layer 23 is disposed between the first top coat layer 22a and the second top coat layer 22b so as to be formed inside the top coat layer 22 from the surface. The dense layer 23 is formed of the same material as the top coat layer 22 and has a smaller porosity than the top coat layer 22. Specifically, the dense layer 23 of the present embodiment is formed by spraying the same YSZ or YbSZ as the top coat layer 22 as a thermal spray material. The dense layer 23 of the present embodiment is formed so that the porosity is in the range of 1% or more and less than 4%. The dense layer 23 is formed to have a film thickness that does not exceed 20% with respect to the film thickness of the entire top coat layer 22 obtained by adding the film thickness of the first top coat layer 22a and the second top coat layer 22b. The For example, in the present embodiment, the dense layer 23 is preferably formed with a thickness of 10 μm or less when the thickness of the topcoat layer 22 is about 500 μm.

Next, the thermal barrier coating method S2 for laminating the thermal barrier coating material 20 on the base material 10 will be described.
First, as the base material forming step S1, the base material 10 is formed into a target shape (in the present embodiment, the shape of the moving blade 7). In the present embodiment, the Ni base alloy is used for the base material 10 as described above.

  The thermal barrier coating method S2 is performed after the base material forming step S1. The thermal barrier coating method S2 includes a bond coat layer laminating step S21, a first top coat layer laminating step S22, a dense layer laminating step S23, a second top coat layer laminating step S24, and a surface adjustment step S25.

  The bond coat layer stacking step S21 is performed after the base material forming step S1. In the bond coat layer stacking step S <b> 21, the bond coat layer 21 is stacked on the surface of the base material 10. In the bond coat layer stacking step S21 of the present embodiment, for example, the bond coat layer 21 is formed by spraying the surface of the base material 10 by low pressure plasma spraying using a metal spray powder of MCrAlY alloy.

  The first top coat layer lamination step S22 is performed after the bond coat layer lamination step S21. In the first top coat layer laminating step S <b> 22, the first top coat layer 22 a is laminated on the bond coat layer 21. In the first topcoat layer laminating step S22 of the present embodiment, for example, a YSZ powder is used as a spraying material, and the first topcoat layer 22a is bond-coated by an atmospheric pressure plasma spraying method (ATMOSPHERIC pressure Plasma Spray: APS). Formed on layer 21.

  The dense layer lamination step S23 is performed after the first topcoat layer lamination step S22. In the dense layer lamination step S23, the dense layer 23 is laminated on the first topcoat layer 22a. The dense layer laminating step S23 of the present embodiment uses, for example, the thermal spray material used in the first topcoat layer laminating step S22, and under the conditions different from those of the first topcoat layer laminating step S22, the atmospheric pressure plasma spraying method. As a result, the dense layer 23 is formed. Specifically, in the dense layer laminating step S23 of the present embodiment, the spraying distance, which is the distance between the tip of the nozzle of a thermal spraying apparatus (not shown) that sprays the thermal spraying material, and the base material 10 is set as the first topcoat layer laminating step S22. Implement closer. For example, when the spraying distance in the first topcoat layer stacking step S22 is set to 150 mm, the spraying distance in the dense layer stacking step S23 is set to be gradually reduced to about 100 mm.

  In the dense layer laminating step S23 of the present embodiment, the dense layer 23 is formed by reducing the spraying distance, but the present invention is not limited to this, and the porosity is formed so as to be smaller than that of the topcoat layer 22. I can do it. For example, the porosity may be reduced by increasing the spraying current of the spraying device.

  The second top coat layer lamination step S24 is performed after the dense layer lamination step S23. In the second topcoat layer laminating step S24, the second topcoat layer 22b is laminated on the dense layer 23. The second topcoat layer lamination step S24 of the present embodiment is performed under the same materials and conditions as the first topcoat layer lamination step S22, and the second topcoat layer 22b is formed on the dense layer 23.

  After performing 2nd topcoat layer lamination process S24, surface adjustment process S25 which adjusts the state of the surface of thermal barrier coating material 20 is implemented. In the surface adjustment step S25, in order to adjust the film thickness of the formed thermal barrier coating material 20 as a whole, or to make the surface smoother and reduce the heat transfer coefficient to the moving blade 7, the second topcoat layer The surface condition of the thermal barrier coating material 20 is adjusted by slightly shaving 22b. In the surface adjustment step S25 of the present embodiment, the second top coat layer 22b is scraped by several μm, the surface of the second top coat layer 22b is smoothed, and the film thickness of the entire thermal barrier coating material 20 is uniform. adjust.

  According to the thermal barrier coating material 20 and the thermal barrier coating method S2 as described above, the porosity is between the first top coat layer 22a and the second top coat layer 22b. By forming the dense layer 23 smaller than the layer 22b, penetration of the molten salt into the first topcoat layer 22a can be prevented. That is, the dense layer 23 can be formed without being exposed on the surface by not forming the dense layer 23 on the surface side of the second top coat layer 22b. Therefore, the dense layer 23 can be protected by the second topcoat layer 22b. Thereby, a part of the surface is adjusted in order to adjust the film thickness of the thermal barrier coating material 20 as a whole when foreign matter comes into contact with the moving blade 7 during operation of the gas turbine 1 or the like or in the surface adjustment step S25. Even if it is a case where it cuts off, it can suppress that the dense layer 23 is damaged. Therefore, the dense layer 23 can be prevented from being damaged by foreign matters other than the molten salt, and the heat shielding property to the turbine member such as the moving blade 7 used for a long time can be stably secured.

  Conventionally, as shown in FIG. 5A, pores and layer defects are present in the top coat layer 22 at a rate of about 10% in order to ensure heat shielding properties. When the molten salt penetrates into the thermal barrier coating material 20, the penetrated molten salt is accumulated in the pores and layered defects, and the strength of the top coat layer 22 is weakened. Then, by using the moving blade 7 having the thermal barrier coating material 20 on the surface in a high temperature and high pressure environment, the top coat layer 22 is subjected to thermal stress, and the molten salt accumulated in the pores and layered defects. Crack 30 develops. Thereafter, the molten salt is further accumulated in the propagated crack 30 and thermal stress acts, whereby the crack 30 further develops. By repeating this, a large crack 30 is formed in the topcoat layer 22, and it is considered that the topcoat layer 22 is peeled off as shown in FIG.

  FIG. 6 shows the result of analyzing the degree of penetration of sulfur, which is one of the components of the molten salt, in the top coat layer 22. As shown in FIG. 6 (a), when the porosity is 10 to 12%, the permeation of sulfur is recognized as indicated by the white dots in the figure. On the other hand, as shown in FIG. 6 (b), it can be seen that when the porosity is reduced to 3 to 8%, there are almost no white spots in the figure, and sulfur permeation is suppressed. That is, the penetration of the molten salt can be suppressed by setting the porosity to 8% or less. Therefore, by forming the dense layer 23 with a low porosity, it is possible to suppress the penetration of the molten salt to the inside of the dense layer 23. Therefore, the penetration of the molten salt can be effectively suppressed by forming the dense layer 23 so that the porosity falls within the range of 1% or more and less than 4% as in the present embodiment. As a result, even if the molten salt has penetrated into the second top coat layer 22b, the dense layer 23 can prevent the penetration into the first top coat layer 22a. Therefore, damage such as peeling of the first topcoat layer 22a can be suppressed, and the topcoat layer 22 can be completely peeled off to prevent the performance of the topcoat layer 22 such as a heat shielding effect from being completely lost. .

  Further, when the dense top layer 23 is formed on the entire topcoat layer 22, it is difficult to ensure sufficient heat shielding properties due to the low porosity. However, by forming the dense layer 23 such that the film thickness of the dense layer 23 does not exceed 20% with respect to the top coat layer 22, the top coat layer 22 is peeled off by the molten salt while ensuring the heat shielding property by the top coat layer 22. Can be suppressed. Therefore, it is possible to form a highly reliable thermal barrier coating material 20 that is difficult to damage over a long period of time and can ensure thermal barrier properties.

  Further, by using such a thermal barrier coating material 20, it is possible to form a turbine member such as the moving blade 7 with high reliability capable of ensuring thermal insulation over a long period of time.

  Furthermore, according to the gas turbine 1 having the above-described configuration, the turbine member is hardly damaged, and the maintainability can be improved. Therefore, the operation stop time of the gas turbine 1 for maintenance can be shortened.

<< Second Embodiment >>
Next, the thermal barrier coating material 20a of the second embodiment will be described with reference to FIG.
In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. The thermal barrier coating material 20a of the second embodiment is different from the first embodiment with respect to the dense layer 23.

  That is, in the second embodiment, the ultrathin dense layer 230 having a thinner and denser structure than the dense layer 23 of the first embodiment is formed. The ultra-thin dense layer 230 is formed within a thickness range of 0.1 μm to 2 μm. The ultrathin dense layer 230 is formed using a suspension plasma spray (SPS). The suspension plasma spraying method is a method in which a turbid liquid in which fine powders of nano to submicron are dispersed in a solvent is directly put into plasma instead of a powder material as a spraying material.

  Specifically, the ultrathin dense layer 230 formed in the second embodiment is formed by suspension plasma spraying using particles of the same material as that used when forming the topcoat layer 22. For example, the ultrathin dense layer 230 is formed on the first topcoat layer 22a by a suspension plasma spraying method using a turbid liquid in which YSZ is dispersed. The ultrathin dense layer 230 is formed with a porosity smaller than that of the topcoat layer 22 as well as the dense layer 23 of the first embodiment. The ultrathin dense layer 230 is formed with a film thickness of about 1 μm, for example.

  According to the thermal barrier coating material 20a as described above, even if the ultrathin dense layer 230 having a film thickness of about 1 μm is formed on the first topcoat layer 22a, the film thickness is very thin. The uneven shape on the surface of the layer 22a on the ultrathin dense layer 230 side is hardly changed. That is, the shape of the surface of the ultrathin dense layer 230 on the second topcoat layer 22b side is such that the irregularities on the surface of the first topcoat layer 22a are transferred. Therefore, even when the second topcoat layer 22b is formed on the ultrathin dense layer 230, the second topcoat layer 22b is formed directly on the first topcoat layer 22a without forming the ultrathin dense layer 230. The same interlayer strength can be generated between the first topcoat layer 22a and the ultrathin dense layer 230 and between the first topcoat layer 22a and the ultrathin dense layer 230. Therefore, the first topcoat layer 22a and the second topcoat layer 22b can be firmly bonded to the ultrathin dense layer 230, and it is possible to suppress peeling at the boundary with the ultrathin dense layer 230. it can.

  Furthermore, since the ultra-thin dense layer 230 has a very thin film thickness of about 1 μm, it does not hinder heat conduction between the first top coat layer 22a and the second top coat layer 22b. Therefore, even if the ultrathin dense layer 230 is formed between the first topcoat layer 22a and the second topcoat layer 22b, it is possible to suppress the heat shielding property from being lowered as a whole of the topcoat layer 22. it can.

  In addition, since the particles are formed by the suspension plasma spraying method, the particles are small in the layer, so that a very dense structure is formed, and the ultrathin dense layer 230 can be formed as a layer having a smaller porosity. Therefore, it is possible to more effectively prevent the molten salt from penetrating into the first topcoat layer 22a.

[Example]
Hereinafter, a method for forming the dense layer 23 between the first top coat layer 22a and the second top coat layer 22b will be described by way of example, but the present invention is not limited by the following description.

(Implementation method)
In this embodiment, the first top coat layer laminating step S22 to the second top coat layer laminating step S24 are performed by the atmospheric pressure plasma spraying method using the same thermal spraying apparatus using YSZ as the thermal spray material. Specifically, in this embodiment, the spraying speed, which is the spraying speed of the spraying material to the base material 10 from the nozzle of the spraying device, is changed. It should be noted that the settings of other thermal spraying devices such as thermal spraying current are made constant. Then, the first top coat layer laminating step S22 to the second top coat layer laminating step S24 are continuously performed by a thermal spraying apparatus.

(Implementation conditions for the first topcoat layer lamination step S22)
Thermal spraying distance: 150 [mm]
Thermal spraying speed: 300 [mm / sec]
(Execution conditions for dense layer stacking step S23)
Thermal spraying distance: 150 [mm]
Thermal spraying speed: 100 to 120 [mm / sec]
(Implementation conditions for the second topcoat layer lamination step S24)
Thermal spraying distance: 150 [mm]
Thermal spraying speed: 300 [mm / sec]

  As a result of performing the first topcoat layer laminating step S22 to the second topcoat layer laminating step S24 under the above-mentioned conditions, as shown in FIG. 8, it is clearer than the first topcoat layer 22a and the second topcoat layer 22b. It was confirmed that a dense layer 23 having a low porosity was formed. Further, it has been found that the dense layer 23 can be laminated between the first top coat layer 22a and the second top coat layer 22b only by adjusting the conditions without changing the thermal spraying apparatus or the like.

  Although the embodiments of the present invention have been described in detail with reference to the drawings, the configurations and combinations of the embodiments in the embodiments are examples, and the addition and omission of configurations are within the scope not departing from the gist of the present invention. , Substitutions, and other changes are possible. Further, the present invention is not limited by the embodiments, and is limited only by the scope of the claims.

  The first top coat layer 22a and the second top coat layer 22b are not limited to being formed under the same conditions using the same material as in the present embodiment, and are formed as separate structures. May be. For example, the porosity of the first top coat layer 22a and the second top coat layer 22b may be formed separately, or may be formed using different materials.

  Further, the bond coat layer 21 and the top coat layer 22 may be formed by a method other than the present embodiment. For example, low-pressure plasma spraying may be used as electric spraying other than atmospheric pressure plasma spraying, and flame spraying or high-speed flame spraying may be used as gas spraying. Moreover, you may form by methods other than a thermal spraying method, for example, you may use an electron beam physical vapor deposition method.

  Further, the first topcoat layer 22a and the second topcoat layer 22b are not limited to being formed to the same film thickness as in the present embodiment, but are not limited to conditions such as the environment in use and shielding. What is necessary is just to set suitably according to the position which wants to form the dense layer 23 in the thermal coating material 20. FIG. For example, the second topcoat layer 22b may be formed very thin as about 5 μm, and the first topcoat layer 22a may be formed very thick as about 400 μm, or vice versa.

  Furthermore, in the above-described configuration, the case where the present invention is applied to the moving blade 7 has been described. However, other turbine members, such as nozzles and cylinders constituting the stationary blade 8 of the gas turbine 1 and the combustor 3, etc. The present invention may be applied to these members.

DESCRIPTION OF SYMBOLS 1 ... Gas turbine 2 ... Compressor 3 ... Combustor 4 ... Turbine main body A ... Compressed air G ... Combustion gas 5 ... Rotor 6 ... Casing 7 ... Moving blade 71 ... Moving blade main body 72 ... Platform 73 ... Blade root 74 ... Shroud 8 DESCRIPTION OF SYMBOLS ... Static blade 10 ... Base material 20, 20a ... Thermal barrier coating material 21 ... Bond coat layer 22 ... Top coat layer 22a ... First top coat layer 22b ... Second top coat layer 23 ... Dense layer S1 ... Base material formation step S2 ... thermal barrier coating method S21 ... bond coat layer laminating step S22 ... first top coat layer laminating step S23 ... dense layer laminating step S24 ... second top coat layer laminating step S25 ... surface conditioning step 30 ... crack 230 ... ultra thin dense layer

Claims (7)

A bond coat layer as a metal bonding layer laminated on the base material;
A topcoat layer comprising ceramic laminated on the bondcoat layer;
A dense layer that is formed inside the surface in the top coat layer, is formed of the same material as the top coat layer, and has a smaller porosity than the top coat layer,
Equipped with a,
The topcoat layer, said across the dense layer are both inside and surface, the same materials and thermal barrier coatings that are formed by the same porosity. 2. The heat shield according to claim 1, wherein the same porosity means that the porosity of the top coat layer on the inner side and the front side with respect to the dense layer is within a range of 8% to 15%, respectively. Coating material. The thermal barrier coating material according to claim 1 or 2 , wherein a porosity of the dense layer is in a range of 1% or more and less than 4%. The thermal barrier coating material according to any one of claims 1 to 3, wherein a film thickness of the dense layer is in a range of 0.1 µm to 2 µm. The turbine member which has the said thermal barrier coating material as described in any one of Claims 1-4 on the surface. A turbine comprising the turbine member according to claim 5 . A bond coat layer laminating step of laminating a bond coat layer as a metal bonding layer on the base material;
A first topcoat layer laminating step, which is performed after the bond coat layer laminating step, and laminating a first topcoat layer containing ceramic on the bond coat layer;
A dense layer laminating step that is performed after the first topcoat layer laminating step and is formed of the same material as the first topcoat layer and has a smaller porosity than the first topcoat layer; ,
Second topcoat layer laminating step, which is performed after the dense layer laminating step, and is formed by laminating a second topcoat layer containing ceramic on the dense layer with the same material and the same spray distance as the first topcoat layer. A thermal barrier coating method comprising: