JP5943649B2 - Manufacturing method of thermal barrier coating material - Google Patents

Description

  The present invention relates to a method for manufacturing a thermal barrier coating applied to a member used in a high temperature environment such as a moving blade and a stationary blade of a gas turbine or a combustor, and more particularly to formation of a top coat layer of a thermal barrier coating material.

  A power generation device such as a gas turbine is used in a high temperature environment. Therefore, the stationary blades and moving blades constituting the gas turbine, the wall material of the combustor, and the like are made of heat resistant members. Further, a thermal barrier coating (TBC) is formed on the base material of the heat resistant member to protect the heat resistant member from high temperature.

The TBC has a structure in which a metal bonding layer (undercoat layer) and a ceramic layer (topcoat layer) are laminated from the base material side.
The undercoat layer mainly contains an MCrAlY alloy (M: represents at least one element of Co and Ni) excellent in oxidation resistance, and is sprayed on the substrate. An undercoat layer is provided with the function as a binder which couple | bonds a base material and a topcoat layer with the corrosion resistance function to a base material.

The top coat layer is applied to the undercoat layer by a plasma spraying method using a zirconia (ZrO ₂ ) ceramic powder material. In detail, the ceramic powder material is heated and melted with a plasma jet and sprayed onto the undercoat layer to form a topcoat layer.

  The cross-sectional structure of the topcoat layer can be broadly divided into a “porous structure” and a “longitudinal crack structure”. FIG. 14 shows a cross-sectional view of a thermal barrier coating material in which the cross-sectional structure of the topcoat layer is a porous structure. FIG. 15 shows a cross-sectional view of a thermal barrier coating material in which the cross-sectional structure of the topcoat layer is a vertically cracked structure. In the thermal barrier coating material shown in FIGS. 14 and 15, an undercoat layer 2 and a topcoat layer 3 are sequentially laminated on a heat resistant substrate 1.

  As shown in FIG. 14, the “porous structure” has a structure including a large number of pores 4 formed from gaps or the like of the ceramic powder material. By providing the holes 4 in the top coat layer 3, the effect of lowering the thermal conductivity of the thermal barrier coating material can be obtained.

  As shown in FIG. 15, the “longitudinal crack structure” has a structure in which cracks (vertical cracks) 5 are included in the film thickness direction of the top coat layer 3. By providing the vertical crack 5, the thermal strain can be absorbed by the vertical crack 5, so that the effect of reducing the thermal stress and making it difficult for the top coat layer 3 to peel off is obtained. Patent Document 1 describes a method of forming vertical cracks in a topcoat layer using a laser beam.

Japanese Patent No. 4434667 (Claim 1)

  Since the thermal barrier coating material is required to have high thermal barrier properties, it is desirable that the top coat layer has a porous structure. However, the porous structure tends to peel off due to thermal stress due to a difference in thermal expansion during high temperature operation of the gas turbine. On the other hand, when the topcoat layer has a vertically cracked structure, it is difficult to peel off, but since there are few pores in the structure, the thermal conductivity tends to increase.

  In order to achieve both low thermal conductivity of the thermal barrier coating material and high heat resistance against thermal stress, it is desirable to form a top coat layer that is porous and includes vertical cracks. However, in order to form a vertically cracked structure, it is necessary to make the topcoat layer dense, and it is difficult to make it compatible with a porous structure. When the top coat layer is formed by thermal spraying, or when vertical cracks are formed using a laser beam as described in Patent Document 1, in the top coat layer having a porosity of 8% by volume or more, It becomes easy to form a lateral crack instead of a crack.

  This invention is made | formed in view of such a situation, Comprising: It aims at providing the manufacturing method of the thermal-insulation coating material which has a topcoat layer which has a porous structure and a vertical crack structure | tissue.

In order to solve the above-mentioned problems, the method for producing a thermal barrier coating material of the present invention employs the following means.
The present invention is a method for manufacturing a thermal barrier coating material comprising an undercoat layer and a topcoat layer in this order on a heat-resistant substrate, wherein the ceramic powder and a predetermined amount of the resinous powder are added to the undercoat under predetermined spraying conditions. A top coat forming step of spraying on the coat layer to form a top coat layer, a crack forming step of forming a crack extending in the thickness direction in the top coat layer, and the heat resistant substrate after the crack forming step And a pore forming step of forming pores in the topcoat layer , wherein the ceramic powder has an average particle size of 10 μm or more and 45 μm or less, and the predetermined amount of the resinous powder is mixed with the ceramic powder. to provide a method of manufacturing to that thermal barrier coatings with more than 20 wt% 3 wt% or more of the total combined weight of the resin powder.

  According to the said invention, after forming the crack (longitudinal crack) extended in a thickness direction in a topcoat layer, a pore is formed. Since the top coat layer is formed so as to contain the resinous powder, pores can be formed in the topcoat layer by vaporizing the resinous powder by heat treatment. The pores contained in the top coat layer have the effect of lowering the thermal conductivity of the thermal barrier coating material. The porosity of the topcoat layer can be controlled by adjusting the mixing amount of the resinous powder. Therefore, the thermal spraying conditions suitable for vertical crack formation can be selected for thermal spraying when forming the topcoat layer. The topcoat layer in which the vertical crack is formed is difficult to peel off against thermal stress.

  In one aspect of the invention, the top coat layer supplies a mixed powder obtained by mixing the ceramic powder and the predetermined amount of the resinous powder in advance to the plasma frame, or supplies the ceramic powder into the plasma frame. It is formed by supplying the predetermined amount of resinous powder so as to be mixed with the ceramic heated and melted in the plasma flame outside the plasma flame.

  By using the mixed powder, the configuration of the plasma spraying apparatus can be further simplified. Further, when the resinous powder is supplied with the plasma frame removed, it is possible to prevent evaporation of the resinous powder due to heat at the time of forming the topcoat layer, so that a desired amount of resin is contained in the topcoat layer. It becomes easy. In addition, the porosity in the topcoat layer can be increased.

  In one aspect of the invention, in the crack formation step, the crack can be formed by setting the predetermined spraying condition to a condition capable of forming a crack.

  According to one aspect of the present invention, the topcoat layer is formed by setting the thermal spraying condition during the formation of the topcoat layer to a condition capable of crack formation, that is, a condition such that the structure of the topcoat layer becomes denser. At the same time as forming, longitudinal cracks can also be formed. In order to make the structure of the top coat layer more precise, it is effective to increase the output of the spray gun and shorten the spray distance.

  In one aspect of the invention, in the crack forming step, the crack may be formed by irradiating a laser beam under a predetermined irradiation condition on a top coat layer formed by spraying the mixed powder.

  According to one embodiment of the present invention, since vertical cracks are formed by irradiating a laser beam after the topcoat layer is formed, restrictions on spraying conditions during the formation of the topcoat layer are alleviated. In particular, since the spraying distance can be separated, the workability during construction can be improved.

  According to the present invention, pores can be formed in the topcoat layer by heat treatment after the formation of vertical cracks by mixing the resinous powder with the thermal spray material of the topcoat layer to form a sprayed film. This makes it possible to manufacture a thermal barrier coating material having a topcoat layer that has both a porous structure and a longitudinal crack structure. Such a thermal barrier coating material is a thermal barrier coating material having low thermal conductivity and high peel resistance.

It is sectional drawing of the thermal barrier coating material manufactured with the manufacturing method of the thermal barrier coating material which concerns on 1st Embodiment. It is a schematic sectional drawing of a plasma spray gun. It is a microscope picture of the cross-sectional microstructure of a thermal barrier coating material. It is a microscope picture of the cross-sectional microstructure of a thermal barrier coating material. It is a microscope picture of the cross-sectional microstructure of a thermal barrier coating material. It is the schematic which shows the supply method of ceramic powder and resinous powder. It is the schematic which shows the supply method of ceramic powder and resinous powder. 2 is a photomicrograph of a cross-sectional microstructure of a test piece 1. 3 is a micrograph of a cross-sectional microstructure of a test piece 2. 2 is a photomicrograph of a cross-sectional microstructure of a test piece 3. 3 is a micrograph of a cross-sectional microstructure of a test piece 4. 2 is a micrograph of a cross-sectional microstructure of a test piece 5. It is sectional drawing of the thermal barrier coating material manufactured with the manufacturing method of the thermal barrier coating material which concerns on 3rd Embodiment. It is sectional drawing of the conventional thermal barrier coating material by which the cross-sectional structure of a topcoat layer is made into a porous structure. It is sectional drawing of the conventional thermal-insulation coating material by which the cross-sectional structure of a topcoat layer is made into a vertical crack structure.

Below, one Embodiment of the manufacturing method of the thermal-insulation coating material which concerns on this invention is described with reference to drawings.
[First Embodiment]
The thermal barrier coating manufactured by the thermal barrier coating material manufacturing method according to the present embodiment has a configuration in which an undercoat layer and a topcoat layer are sequentially laminated on a heat resistant substrate.
The heat-resistant substrate is a Ni-based heat-resistant alloy such as IN738LC.
The undercoat layer is formed on the heat resistant substrate by a low pressure plasma spraying method or the like. The undercoat layer is made of MCrAlY alloy (M represents at least one element of Ni and Co), and is generally 0.05 mm to 0.2 mm in thickness.

The topcoat layer is formed on the undercoat layer by atmospheric pressure plasma spraying (APS). The topcoat layer is made of YSZ (yttria stabilized zirconia), YbSZ (ytterbia stabilized zirconia), DySZ (dysprosia stabilized zirconia), ErSZ (erbia stabilized zirconia), SmYbZr ₂ O ₇ or the like. The thickness of the top coat layer is set to 0.2 mm or more and 1.0 mm or less.

  The topcoat layer has a plurality of pores in the layer. If the pores are too large, the thermal cycle durability of the topcoat layer is lowered, so the pore size is 1 μm or more and 50 μm or less, preferably 3 μm or more and 20 μm or less. By setting the size of the pores within the above range, it is possible to suppress a decrease in thermal cycle durability of the sprayed film. The porosity of the topcoat layer is 1% by volume to 20% by volume, preferably 5% by volume to 15% by volume. By setting the porosity within the above range, a top coat layer having a low thermal conductivity is obtained, and the heat shielding property of the heat shielding coating material is improved. When the porosity is less than 5% by volume, a vertical crack structure is easily formed, but the heat shielding property is lowered. On the other hand, when the porosity is larger than 15% by volume, the adhesion of the particles in the topcoat layer becomes weak, and there is a concern that the erosion resistance and the like are lowered.

The thermal barrier coating material manufacturing method according to the present embodiment includes a top coat layer forming step, a crack forming step, and a pore forming step. Moreover, in this embodiment, a crack formation process is integrated and implemented in a topcoat layer formation process. In the present embodiment, the undercoat layer is assumed to be formed on a heat resistant substrate by a known method, and the description will focus on the step of forming the topcoat layer on the heat resistant substrate on which the undercoat layer is formed.
FIG. 1 is a cross-sectional view of a thermal barrier coating material manufactured by the thermal barrier coating material manufacturing method according to the present embodiment. 1A is a cross-sectional view of the thermal barrier coating after the crack formation step, and FIG. 1B is a cross-sectional view of the thermal barrier coating after the pore formation step.

(1) Top coat layer forming step and crack forming step (FIG. 1 (A))
First, a mixed powder in which a resin powder is mixed with a ceramic powder is prepared as a thermal spraying powder. The ceramic powder and the resinous powder are sufficiently stirred immediately before spraying to obtain a uniform mixed powder.

The ceramic powder is a powder such as YSZ, YbSZ, DySZ, ErSZ, or SmYbZr ₂ O ₇ . The particle size of the ceramic powder can be appropriately set according to the output of the spray gun used for spraying. For example, when the output of the spray gun is set to a current of 700 A and a voltage of 40 V, the particle size distribution (average particle size) of the ceramic powder is preferably set to 1 μm or more and 125 μm or less. Preferably, it is 10 μm or more and 45 μm or less. By using a finer particle ceramic powder, the heat capacity of the ceramic powder is reduced, so that it can be melted well by thermal spraying heat. By thoroughly melting the ceramic powder to form a sprayed film, the topcoat layer can be made into a dense structure. In addition, when using a spray gun having a higher output than the above spray gun, ceramic powder having a size exceeding 45 μm can be used.

The resinous powder is a thermoplastic resin powder such as polyester or acrylic resin. The particle size of the resinous powder may be appropriately selected according to the size of pores to be formed in the topcoat layer. The particle size distribution (average particle size) of the resinous powder is 1 μm or more and 150 μm or less, preferably 20 μm or more and 100 μm or less. Specifically, the resinous powder includes crosslinked polymethyl methacrylate powder (manufactured by Sekisui Plastics Co., Ltd., MBX-5, average particle size 5 μm), polyester powder (manufactured by Sulzer Metco, Sulzer Meteco 2395, ZrO ₂ 7. 5Y ₂ O ₃ 0.7BN4.5 Polyester, polyester average particle size 30 μm), crosslinked polymethyl methacrylate powder (manufactured by Sekisui Plastics Co., Ltd., MBX-12, average particle size 12 μm), crosslinked polymethyl methacrylate powder (Sekisui) For example, MBX-80 manufactured by Kasei Kogyo Co., Ltd., average particle size 80 μm) can be used.

  The ratio of the resinous powder in the mixed powder is 1% by weight or more and 50% by weight or less, preferably 3% by weight or more and 30% by weight or less.

  Next, the mixed powder is sprayed onto the undercoat layer 2 using an atmospheric pressure plasma spraying method. FIG. 2 shows a schematic cross-sectional view of the plasma spray gun. The plasma irradiation gun shown in FIG. 2 has a cathode 7 and an anode 8 inside. The plasma irradiation gun can generate a plasma 11 by applying a voltage between the cathode 7 and the anode 8 to cause an arc discharge 9 and feeding a plasma gas 10 from behind the cathode 7. In the present embodiment, the mixed powder is supplied from the powder supply port 12 into the plasma flame, and a thermal spray coating is formed on the base material by the mixed powder 13 heated and melted.

  Thermal spraying is performed under the condition that a crack (longitudinal crack) 5 extending in the thickness direction can be formed in the top coat layer 3 simultaneously with the formation of the top coat layer 3. For example, when using a ceramic powder having an average particle size of 10 μm or more and 45 μm or less, the current is 500 A to 800 A, the voltage is 55 V to 70 V, and the spraying distance is 50 mm to 120 mm.

(2) Pore forming step (FIG. 1 (B))
The heat resistant substrate 1 formed up to the top coat layer 3 is subjected to heat treatment in an air atmosphere. The heat treatment is performed in an atmospheric furnace or the like. The heat treatment is performed for a predetermined time at a temperature equal to or higher than a temperature at which the resin 6 contained in the top coat layer 3 is thermally decomposed and a decomposition product generated by the thermal decomposition is vaporized. The heat treatment may be performed, for example, at 400 ° C. to 700 ° C. for 1 hour to 10 hours.

  According to this embodiment, in the topcoat layer forming step, the sprayed film is formed in a state where the resin 6 is mixed. The thermal sprayed film has a dense structure, and after thermal spraying, cracks are generated by the action of thermal stress accompanying a temperature decrease, and the top coat layer 3 having vertical cracks 5 is formed. By forming the vertical crack 5, the thermal stress generated at the interface with the undercoat layer 2 can be relieved, so that the thermal cycle durability of the topcoat layer 3 is improved.

  According to the present embodiment, the pores 4 are formed after the vertical cracks 5 are formed. Since the resin 6 is mixed in the top coat layer 3, the pores 4 can be formed in the top coat layer 3 by heat treatment after forming the sprayed film. That is, even when a sprayed film having a dense structure is formed as the topcoat layer 3, the topcoat layer 3 having a porous structure can be formed by heat treatment later. In addition, since the resin 6 is present in the topcoat layer when the vertical crack is formed, the presence of the pores 4 may hinder the formation of the vertical crack 5 even when the topcoat layer 3 having a high porosity is desired. There is no.

Example 1
A thermal barrier coating material was produced according to the first embodiment. The heat resistant substrate 1 was IN738. The undercoat layer 2 was CoNiCrAlY.
The top coat layer 3 was formed as follows. As the ceramic powder, Amperit 827.054 (manufactured by HC Starck, 7YSZ, particle size distribution (average particle size) 10 μm to 45 μm) was used. As the resinous powder, cross-linked polymethyl methacrylate powder (manufactured by Sekisui Plastics Co., Ltd., MBX-10, average particle size 10 μm) was used.

  A mixed powder obtained by mixing 3% by weight or 6% by weight of a resinous powder with ceramic powder was sprayed onto the undercoat layer 2 to form a topcoat layer 3 (thickness 0.3 mm to 0.5 mm). Moreover, the topcoat layer 3 was similarly formed using the ceramic powder as a comparative control. The spraying conditions were a current of 700 A, a voltage of 60 V, and a spraying distance of 70 mm. The heat-resistant substrate 1 on which the topcoat layer 3 was formed was placed in an atmospheric furnace and heat-treated at 400 ° C. for 4 hours to obtain a thermal barrier coating material.

  About the thermal-insulation coating material manufactured above, the cross-sectional microstructure was observed with the microscope. 3 to 5 show micrographs of the cross-sectional microstructure of the thermal barrier coating material. 3 is a ceramic powder, FIG. 4 is a mixed powder obtained by mixing 3% by weight of a resinous powder, and FIG. 5 is a mixed powder obtained by mixing 6% by weight of a resinous powder. It is a micrograph. According to FIGS. 3 to 5, as the mixing amount of the resinous powder increases, the pores in the top coat layer (the black dots in the figure have a size of about φ1 μm to φ30 μm. The thickness of the coating is 2 or more per 1 mm in the horizontal direction.The thicker the coating, the greater the thermal stress in the layer and the easier it is to form vertical cracks. 2 mm), the vertical cracks are clearly observed.

[Second Embodiment]
The manufacturing method of the thermal barrier coating material according to the present embodiment is the same as that of the first embodiment except that the method for supplying the ceramic powder and the resinous powder in the top coat layer forming step is different.
First, ceramic powder and resinous powder are separately prepared as thermal spraying powders. The ceramic powder and resinous powder used are the same as in the first embodiment.
The resinous powder is 1% by weight to 50% by weight, preferably 3% by weight to 30% by weight, based on the total weight of the ceramic powder and the resinous powder.

  Next, a ceramic powder and a resin powder are sprayed on the undercoat layer 2 using an atmospheric pressure plasma spraying method. FIG. 6 shows a method for supplying ceramic powder and resinous powder. In this embodiment, ceramic powder and resinous powder are supplied from separate supply ports. Specifically, the ceramic powder is supplied from the powder supply port 12 into the plasma flame as in the first embodiment. The resinous powder is supplied from the resinous powder supply port 14 so as to be mixed with the heated and melted ceramic powder outside the plasma flame. In FIG. 6, the resin powder is supplied by removing the plasma flame by inclining the axis of the resin powder supply port 14 toward the front of the plasma with respect to the normal direction of the plasma flame.

  According to this embodiment, it is possible to prevent the resinous powder from evaporating due to the heat of the plasma frame during the formation of the topcoat, so that the amount of the resinous powder contained in the topcoat layer can be easily controlled.

  The method of supplying the resinous powder by removing the plasma flame is not limited to tilting the axis of the resinous powder supply port 14. For example, as shown in FIG. 7, the resinous powder supply port 14 may be arranged at a predetermined distance from the powder supply port 12 to the front of the plasma.

(Example 2)
A thermal barrier coating material was manufactured according to the first embodiment and the second embodiment.
The heat-resistant substrate 1 was IN738, the undercoat layer 2 was CoNiCrAlY, and the topcoat layer 3 was formed on the undercoat layer 2.
As the ceramic powder, Amperit 827.054 (manufactured by HC Starck, 7YSZ, particle size distribution (average particle size) 10 μm to 45 μm) was used. As the resinous powder, cross-linked polymethyl methacrylate powder (manufactured by Sekisui Plastics Co., Ltd., MBX-20, MBX-80, average particle size 20 μm or 80 μm) was used.

Table 1 shows the test conditions for forming the topcoat layer.

In the powder supply method of Table 1, “mixing” means that a mixed powder obtained by previously mixing ceramic powder and resinous powder is supplied from the powder supply port 12 according to the first embodiment.
As shown in FIG. 6 of the second embodiment, “separate supply A” is a resin property in which ceramic powder is supplied into the plasma flame from the powder supply port 12 and is inclined by 15 ° with respect to the normal direction of the plasma flame. It means that resinous powder is supplied from the powder supply port 14 to the outside of the plasma flame.
As shown in FIG. 7 of the second embodiment, “separate supply B” is a resin property in which ceramic powder is supplied into the plasma frame from the powder supply port 12 and is disposed at a distance of 30 mm in front of the plasma from the powder supply port. It means that resinous powder is supplied from the powder supply port 14 to the tip of the plasma frame or to the outside. Actually, it is in the form of being entrained in ceramic particles heated and melted in a plasma flame.

  After forming the topcoat layer (thickness 0.3 mm to 0.6 mm) according to the test conditions 1 to 5 shown in Table 1, the heat-resistant substrate 1 on which the topcoat layer 3 was formed was placed in an atmospheric furnace and heated at 400 ° C. Heat treatment was performed for a time, and test pieces 1 to 5 were obtained.

  About the test pieces 1-5, the cross-sectional microstructure was observed with the microscope. 8 to 12 show micrographs of the cross-sectional microstructures of the test pieces 1 to 5. FIG. 1 is a cross-sectional microstructure of a test piece 1 manufactured under the condition 1; FIG. 2 is a cross-sectional microstructure of a test piece 2 manufactured under the condition of 2. FIG. 3 is a cross-sectional microstructure of the test piece 3 manufactured under the condition 3; FIG. 4 is a cross-sectional microstructure of a test piece 4 manufactured under the condition of 4. FIG. 5 is a cross-sectional microstructure of the test piece 5 manufactured under the condition 5.

  8 to 12, it was confirmed that pores exist in the topcoat layer 3 and vertical cracks are also formed in any of the test pieces 1 to 5. Compared with the test piece 1, the porosity in the topcoat layer 3 increased by 1-2% in the test pieces 2-5.

  From the above results, the manufacturing method of the thermal barrier coating material according to the first embodiment and the second embodiment is effective in manufacturing the thermal barrier coating material having the top coat layer having both the porous structure and the vertical crack structure. It can be said that there is. Further, in the first embodiment and the second embodiment, (i) increasing the particle size of the resinous powder, (ii) increasing the mixing amount of the resinous powder, and (iii) reducing the output of the plasma flame. As a result, pores in the topcoat layer can be increased.

[Third Embodiment]
The thermal barrier coating manufactured by the thermal barrier coating material manufacturing method according to the present embodiment has the same configuration as that of the first embodiment. The thermal barrier coating material manufacturing method according to the present embodiment includes a topcoat layer forming step, a crack forming step performed after the topcoat forming step, and a pore forming step. In the present embodiment, the undercoat layer is assumed to be formed on a heat resistant substrate by a known method, and the description will focus on the step of forming the topcoat layer on the heat resistant substrate on which the undercoat layer is formed.
FIG. 2 shows a cross-sectional view of the thermal barrier coating material manufactured by the thermal barrier coating material manufacturing method according to the present embodiment. 13A is a cross-sectional view of the thermal barrier coating after the top coat forming step, FIG. 13B is the crack forming step, and FIG. 13C is the pore-forming step.

(1) Top coat layer forming step (FIG. 13A)
First, as in the first embodiment, a mixed powder obtained by mixing a resin powder with a ceramic powder is prepared as a thermal spraying powder. The ceramic powder and the resinous powder are sufficiently stirred immediately before spraying to obtain a uniform mixed powder. The ceramic powder and resinous powder used are the same as in the first embodiment.

Next, the mixed powder is sprayed onto the undercoat layer 2 using an atmospheric pressure plasma spraying method. The thermal spraying is performed under the condition that the vertical crack 5 is not formed in the top coat layer 3 and the dense structure in which the porosity does not exceed 10% is formed simultaneously with the formation of the top coat layer 3.
For example, when ceramic powder having an average particle size of 10 μm or more and 45 μm or less is used, the spraying conditions are a current of 500 A to 700 A, a voltage of 55 V to 70 V, and a spraying distance of 120 mm to 180 mm. More specifically, the spraying conditions are a current of 600 A, a voltage of 40 V, and a spraying distance of 150 mm.

(2) Crack formation process (FIG. 13B)
Scanning is performed while locally irradiating the surface of the top coat layer 3 with a laser beam, and tensile stress is generated in the top coat layer, whereby vertical cracks 5 are formed in the top coat layer 3. Irradiation conditions of the laser beam, the power density ^{40W / mm 2 ~200W / mm 2} , the energy density of ^{2J / mm 2 ~5J / mm 2} , and the power product of the density and the energy density is 180W ^/ mm 2 · J ^/ mm Set to be ² or more. If the power density and energy density are too low, the generation of vertical cracks will be insufficient. On the other hand, if the power density is too high, the laser heat input becomes excessive and it becomes difficult to form a sound sprayed film. On the other hand, if the energy density is too large, it causes peeling of the sprayed film and deterioration of surface properties. Moreover, in order to form the vertical crack 5 in the topcoat layer 3, a certain amount of laser heat input is required, so the product of the power density and the energy density is 180 W / mm ² · J / mm ² or more. Is desirable.

(3) Pore forming step (FIG. 13C)
The heat resistant substrate 1 formed up to the top coat layer 3 is subjected to heat treatment in an air atmosphere. The heat treatment is performed in the same manner as in the first embodiment.

  According to this embodiment, since it is not necessary to form the crack 5 at the time of forming the top coat layer, restrictions on the thermal spraying conditions at the time of forming the top coat are alleviated. Specifically, the output of the spray gun can be reduced to increase the spray distance. Thereby, the workability | operativity at the time of thermal spraying film construction can be improved. This embodiment is particularly useful when the topcoat layer 3 is formed on a member having a complicated shape having a curve, such as a moving and stationary blade of a gas turbine.

1 heat-resistant substrate 2 undercoat layer 3 topcoat layer 4 pores (pores)
5 Longitudinal crack (crack extending in the thickness direction)
6 Resin 7 Cathode 8 Anode 9 Arc discharge 10 Plasma gas 11 Plasma 12 Powder supply port 13 Mixed powder 14 heated and melted Resin powder supply port

Claims (5)

On a heat resistant substrate, a method for producing a thermal barrier coating material comprising an undercoat layer and a topcoat layer in order,
A top coat layer forming step of thermally spraying ceramic powder and a predetermined amount of resinous powder on the undercoat layer under a predetermined spraying condition to form a top coat layer;
A crack forming step for forming a crack extending in the thickness direction in the top coat layer,
After the crack forming step, heat-treating the heat-resistant substrate, and forming pores in the topcoat layer,
Equipped with a,
The average particle size of the ceramic powder is 10 μm or more and 45 μm or less,
Wherein a predetermined amount of the resin powder, the ceramic powder and method for producing the resin powder and the combined total weight of 3 to 20% by weight and to that thermal barrier coating material.   The method for manufacturing a thermal barrier coating material according to claim 1, wherein in the top coat layer forming step, a mixed powder obtained by mixing the ceramic powder and the predetermined amount of the resinous powder in advance is supplied to a plasma frame.   In the top coat layer forming step, the ceramic powder is supplied into a plasma frame, and the predetermined amount of resinous powder is supplied to be mixed with the ceramic heated and melted in the plasma frame outside the plasma frame. The manufacturing method of the thermal-insulation coating material of Claim 1.   The method for manufacturing a thermal barrier coating material according to any one of claims 1 to 3, wherein in the crack formation step, the crack is formed by setting the predetermined spraying condition to a condition capable of crack formation. In the crack formation step,
The thermal barrier coating material according to any one of claims 1 to 3, wherein the crack is formed by irradiating a laser beam under a predetermined irradiation condition on a topcoat layer formed by spraying the mixed powder. Method.

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