JPH1161438A - Heat shielding coating member and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve shielding performance for use, to prevent production of cracks and peeling, and to improve durability by forming a dense MCrAlY alloy layer and a partially stabilized zirconia layer having specified porosity to form a heat shielding coating film on the surface of a sintered hard alloy member of a gas turbine or jet engine. SOLUTION: An MCrAlY alloy layer 2 having excellent corrosion resistance and oxidation resistance and a Y2 O3 partially stabilized zirconia layer 3 which has low thermal conductivity and is chemically stable are formed by thermal spraying on a sintered hard alloy metal base body 1 essentially comprising Ni, Co or Fe to obtain a heat-shielding coating member. In this method, the MCrAlY alloy layer 2 as a first layer is made dense having <=2% porosity of pores 4 in the layer, while the partially stabilized zirconia layer 3 is made porous with 5 to 60% porosity. The partially stabilized zirconia essentially consists of ZrO2 and is stabilized by adding Y3 O3 , MgO, CaO2 , etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-temperature component material used in a high-temperature oxidizing or corrosive atmosphere, such as a gas turbine or a jet engine, in which a metal substrate is coated with a heat-insulating material. The present invention relates to a thermal coating member and a method for manufacturing the same.

[0002]

2. Description of the Related Art In motors such as gas turbines and jet engines, research and development for the purpose of improving thermal efficiency has been vigorously conducted. Since one of the most influential means for improving the thermal efficiency is to raise the operating gas temperature, the improvement in the thermal efficiency generally tends to force the components to a higher temperature in a harsh use environment. Therefore, the rotor blade,
High-temperature parts that come into direct contact with combustion gas, such as vanes and combustors,
Investigations have been made from two viewpoints so as to withstand use in a high-temperature environment.

[0003] First, there is a study on measures for improving cooling characteristics for lowering the temperature of component materials. In order to improve the cooling characteristics, it is effective in principle to increase the flow rate of the cooling gas (air). However, simply increasing the flow rate of the cooling gas decreases the combustion gas temperature, and conversely, the thermal efficiency often decreases.

Therefore, as a method of improving the cooling performance without increasing the flow rate of the cooling gas, a method of increasing the heat transfer coefficient between the material and the cooling gas typified by film cooling or impingement cooling, a return of the blade cooling passage, and the like. There has been proposed a method of gradually reducing heat with a small flow rate of a cooling gas, such as a method of increasing a contact area between a material and a cooling gas represented by a flow structure.

[0005] However, any of these methods leads to complication of the device structure and component structure in any case. Therefore, it has been pointed out that the control of the device becomes complicated and the manufacturing cost increases.

A second study is a measure for improving the heat resistant temperature of a material. Already, Ni, C
The development of o- or Fe-based superalloys is underway. There is also an attempt to further improve the high-temperature strength by using unidirectional solidification or single crystal.

However, in these methods, the use limit temperature is at most 1000 ° C. even from the above-mentioned melting point of the superalloy. Furthermore, as a method of improving heat resistance, the melting point is high,
In addition, use of a ceramic material having excellent oxidation resistance and corrosion resistance can be considered.

[0008] Although there have been trials with ceramics based on SiC or Si ₃ N ₄ , there are drawbacks in that the toughness is inferior and the workability is inferior to metal materials. Therefore, there have been many problems in terms of reliability and cost for wide application as a high-temperature component structural material.

On the other hand, as a method for improving heat resistance while using a metal material having excellent toughness as a strength member,
There is a thermal barrier coating. The thermal barrier coating forms an oxide-based ceramic layer (thermal barrier ceramic layer) having a low thermal conductivity on the surface of the metal substrate to block heat and prevent a temperature rise of the metal substrate. There is also a report that the formation of a heat insulating ceramic layer of several hundred μm can reduce the surface temperature rise of a metal substrate by several tens of degrees Celsius (Japanese Patent Application Laid-Open No. 62-211387).

[0010] Thereby, the temperature rise of the metal base material serving as the strength member can be suppressed, and the temperature of the gas turbine can be increased. That is, in the thermal barrier coating, qualitatively, the greater the thickness of the thermal barrier ceramic layer, the better the thermal barrier performance and the lower the temperature of the metal substrate. Further, the heat shield coating has an advantage that the heat flux from the combustion gas side to the cooling air side is reduced, and the flow rate of the cooling gas can be reduced.

However, there are many problems in applying the thermal barrier coating widely. In particular, the biggest problem is cracking or peeling of the coated thermal barrier ceramic layer. This cracking and peeling of the thermal barrier ceramic layer is due to the inherent properties of the ceramic material itself, which is low in toughness, the thermal stress generated by the thermal expansion difference between the metal substrate and the thermal barrier ceramic, and the metal surface immediately below the thermal barrier ceramic layer. This is considered to be due to deterioration of the material due to oxidation of the material.

Once the heat-insulating ceramic layer is peeled off, the heat-insulating performance deteriorates, so that the temperature of the metal substrate rises.
This may cause major troubles such as melting of the metal base material, creep and fatigue fracture of the metal base material, which also hinder the operation of the equipment.

On the other hand, various studies have hitherto been made with the aim of reducing the peeling of the thermal barrier coating. A typical example of the thermal barrier coating is a two-layer structure in which an MCrAlY alloy layer and an oxide-based ceramic layer such as a low thermal conductive ceramic zirconia-based ceramic are formed on a metal substrate.

The MCrAlY alloy layer is intended to improve the adhesion between the metal substrate and the thermal barrier ceramic layer and to prevent corrosion and oxidation of the metal substrate, and is often formed by a thermal spraying method. . According to the thermal spraying method, although there is an advantage that the type of material can be arbitrarily selected irrespective of metal and ceramic, for example, when the MCrAlY alloy is coated in the atmosphere using a plasma spraying method having a high-temperature heat source, (1) ) There are drawbacks such as being porous, (2) poor adhesion to metal substrates, and (3) poor corrosion and oxidation resistance.

In this regard, in recent years, a method of performing plasma spraying in a reduced pressure inert gas atmosphere substantially free of air (generally referred to as a reduced pressure plasma spraying method).
Has been developed, these disadvantages have been greatly improved, and the durability of the thermal barrier coating has been dramatically improved. Regarding the thermal barrier ceramic layer, many studies have been made on the type and amount of additives for stabilization in order to stabilize the phase of zirconia and improve the thermal cycle characteristics.

However, from the viewpoint of the structure of the layer, the electron beam physical vapor deposition (EB-PVD) partially having a columnar structure is characterized.
At present, there has been little study on the law. In particular, when a sudden temperature change occurs in the heat-insulating ceramic layer such as at the time of starting and stopping, cracking or peeling may occur due to the low toughness of the heat-insulating ceramic layer. This remarkably occurs, for example, when a thick heat insulating ceramic layer is formed, and often causes a problem.

[0017]

As described above, the thermal barrier coating used under high-temperature oxidation and high-temperature corrosive atmosphere conditions, such as a gas turbine, has a problem that the thermal barrier ceramic film is cracked or peeled off, and has a sufficient durability. At present, it is difficult to say that it has reliability and reliability. In particular, there is a large problem in durability and reliability in a thermal barrier coating composed of a thermal barrier ceramic layer having a large thickness in order to greatly reduce the temperature of a metal substrate.

The present invention has been made to solve such problems, and is intended for high-temperature parts used in a high-temperature oxidizing and corrosive atmosphere such as gas turbines and jet engines, and has excellent heat-shielding performance and durability. And a method of manufacturing the same.

[0019]

In order to achieve the above object, the present invention takes the following measures. The invention corresponding to claim 1 is a thermal barrier coating member formed by forming an MCrAlY alloy (M: Ni, Co, Fe or an alloy combining these elements) layer and a partially stabilized zirconia layer on a metal substrate. The porosity of the partially stabilized zirconia layer is 5 to 60%.

In the thermal barrier coating member according to the first aspect of the present invention, by increasing the porosity of the partially stabilized zirconia layer, the thermal conductivity can be reduced, and cracking and peeling can be reduced. it can. Further, since the heat insulation performance per unit thickness is improved, the thickness of the partially stabilized zirconia layer for heat insulation can be reduced with respect to the required heat insulation performance.

According to a second aspect of the present invention, there is provided a heat shield formed by forming an MCrAlY alloy (M: Ni, Co, Fe or an alloy thereof) and a partially stabilized zirconia layer on a metal substrate. In the coating member, the porosity of the partially stabilized zirconia layer is set to 10 to 30%.

In the thermal barrier coating member according to the second aspect of the present invention, by setting the porosity of the partially stabilized zirconia layer to 10 to 30%, cracks generated in the partially stabilized zirconia layer are reduced. Since energy can be absorbed by the pores, both toughness and strength can be improved.

According to a third aspect of the present invention, there is provided a method for forming an MCrAlY alloy (M: Ni, Co, Fe or an alloy thereof) layer on a metal substrate, An oxide-based ceramic raw material powder having a particle size of 50 to 100 μm having 95% or more and a primary particle filling rate of 70% or less is supplied into a high-temperature atmosphere and melted, and is melted on the MCrAlY alloy layer. Spraying at a high speed to form a partially stabilized zirconia layer having a high porosity.

In the method for manufacturing a thermal barrier coating member according to the third aspect of the present invention, a partially stabilized zirconia layer having a high porosity can be formed, so that the toughness is excellent. Cracking and peeling of the partially stabilized zirconia layer due to a large temperature change at the time of starting and stopping of the device are reduced.

The invention corresponding to claim 4 is a step of forming an MCrAlY alloy (M: Ni, Co, Fe or an alloy combining these elements) layer on a metal base material, and a step of forming an oxide ceramic and carbon or carbon. A mixture of a material A that sublimates in a high-temperature atmosphere such as an organic substance is used as a raw material powder, and the raw material powder is supplied into a high-temperature atmosphere. Spraying over to form a partially stabilized zirconia layer having a high porosity.

In the method for manufacturing a thermal barrier coating member according to the present invention, a partially stabilized zirconia layer and a mixed powder of carbon and an organic substance are supplied into a high-temperature atmosphere and blown onto the surface of a metal substrate. Since carbon and organic matter are deposited during the flight of the powder or after the powder is deposited on the base material, a partially stabilized zirconia layer having a high porosity can be formed.

According to a fifth aspect of the present invention, there is provided a method for forming an MCrAlY alloy (M: Ni, Co, Fe or an alloy combining these elements) layer on a metal substrate, comprising the steps of: A mixture with a metal or an inorganic compound having a higher vapor pressure than the base ceramic is used as a raw material powder, and the raw material powder is supplied and melted in a high-temperature atmosphere, and is sprayed at high speed onto the MCrAlY alloy layer. After forming a mixed film of an oxide-based ceramic and a metal or an inorganic compound, a step of forming a partially stabilized zirconia layer having a high porosity by removing the metal or the inorganic compound by evaporation at a high temperature is provided.

According to a fifth aspect of the present invention, there is provided a method for manufacturing a thermal barrier coating member, comprising mixing a raw material powder with a mixture of an oxide ceramic and a metal or an inorganic compound having a higher vapor pressure than the oxide ceramic in a high-temperature atmosphere. After melted and supplied into a metal substrate and spraying it on a metal substrate at high speed to form a mixed film, a partially stabilized zirconia layer with high porosity can be obtained by removing the metal or inorganic compound by evaporation at high temperature. Can be formed.

The invention corresponding to claim 6 includes a step of forming an MCrAlY alloy (M: Ni, Co, Fe or an alloy combining these elements) layer on a metal substrate, and a step of forming an oxide ceramic and a metal. The mixture was used as a raw material powder, and the raw material powder was supplied into a high-temperature atmosphere and melted and sprayed onto the MCrAlY alloy layer at a high speed to form a mixed film of an oxide ceramic and a metal. Forming a partially stabilized zirconia layer having high porosity by dissolving and removing only the metal.

[0030] In the method for manufacturing a thermal barrier coating member according to the invention, the mixture of the oxide ceramic and the metal is supplied as a raw material powder into a high-temperature atmosphere and melted. After spraying the mixture at high speed to form a mixed film, only a metal is dissolved and removed with an acid or an alkali to form a partially stabilized zirconia layer having a high porosity.

According to a seventh aspect of the present invention, there is provided a heat shield formed by forming an MCrAlY alloy (M: Ni, Co, Fe or an alloy combining these elements) layer and a partially stabilized zirconia layer on a metal substrate. In the coating member, the partially stabilized zirconia layer has a porosity of 5 on the coating surface side.
A partially stabilized zirconia layer having a porosity of about 60% and a layer having a porosity closer to the interface with the MCrAlY alloy layer and a partially stabilized zirconia layer having a porosity denser than that of the coating surface. It is formed.

In the thermal barrier coating member according to the present invention, for example, when the gas turbine is started and stopped, the coating surface side having a large temperature increase has a porous partial stabilization having a porosity of 5 to 60%. MCrA with toughness as zirconia layer and high thermal stress during steady operation
In the vicinity of the interface with the 1Y alloy layer, a high-strength partially stabilized zirconia layer having a higher porosity and a lower density is used, and cracking and peeling are reduced by forming two partially stabilized zirconia layers having different porosity. be able to.

[0033] The invention corresponding to claim 8 is a heat shield formed by forming an MCrAlY alloy (M: Ni, Co, Fe or an alloy combining these elements) layer and a partially stabilized zirconia layer on a metal substrate. In the coating member, the partially stabilized zirconia layer is formed by gradually changing the porosity so that the coating surface side is porous and the interface side with the MCrAlY alloy layer is dense.

According to a ninth aspect of the present invention, in the method for manufacturing a thermal barrier coating member according to the third aspect of the present invention, the particle size of the secondary particles and the packing ratio of the primary particles of the oxide ceramic raw material powder are changed. The porosity of the partially stabilized zirconia layer is changed using the resulting zirconia layer.

According to a tenth aspect of the present invention, there is provided a method for manufacturing a thermal barrier coating member according to the fourth aspect, wherein the mixing ratio of the oxide-based ceramic and the material A which sublimes out of a high-temperature atmosphere such as carbon or an organic substance. The porosity of the partially stabilized zirconia layer is changed by using the raw material powder having changed.

According to an eleventh aspect of the present invention, there is provided a method for manufacturing a thermal barrier coating member according to the fifth aspect of the present invention, wherein the oxide ceramic and a metal or an inorganic compound having a higher vapor pressure than the oxide ceramic. The porosity of the partially stabilized zirconia layer is changed by using the raw material powder having the changed mixing ratio.

According to a twelfth aspect of the present invention, there is provided the method for manufacturing a thermal barrier coating member according to the sixth aspect of the present invention, wherein the material is partially stabilized by using a raw material powder in which the mixing ratio of the oxide ceramic and the metal is changed. Changes the porosity of the zirconia layer.

In the method for manufacturing a thermal barrier coating member according to the invention according to claims 8 to 12, for example, the coating surface having a large temperature increase when the gas turbine is started and stopped has a high porosity and a steady porosity. Low porosity near the interface with the MCrAlY alloy layer, which has a large thermal stress during operation, and reduces the cracking and peeling by using a partially stabilized zirconia layer with a porosity that gradually decreases from the surface to the interface. Can be done.

According to a thirteenth aspect of the present invention, there is provided a heat shield formed by forming an MCrAlY alloy (M: Ni, Co, Fe or an alloy combining these elements) layer and a partially stabilized zirconia layer on a metal substrate. In the coating member, the partially stabilized zirconia layer has a porosity of 5 to 60%, and the MCrAlY alloy layer has a porosity of 2% or less.

According to a fourteenth aspect of the present invention, there is provided a heat shield formed by forming an MCrAlY alloy (M: Ni, Co, Fe or an alloy thereof) and a partially stabilized zirconia layer on a metal substrate. In the coating member, the partially stabilized zirconia layer has a porosity of 10 to 30%, and the MCrAlY alloy layer has a porosity of 2% or less.

In the thermal barrier coating member according to the present invention, the MCrAlY
By reducing the porosity of the alloy layer, the metal substrate can be protected from corrosive oxidizing gas. Further, since the area of the MCrAlY alloy layer in contact with the corrosive oxidizing gas is small, the absolute amount of corrosive oxidation is reduced, and the stress generated in the partially stabilized zirconia layer due to the volume expansion of the MCrAlY alloy layer due to the corrosive oxidation is reduced. Therefore, cracking and peeling of the partially stabilized zirconia layer can be reduced.

The invention corresponding to claim 15 is claim 1,
Claim 2, Claim 7, Claim 8, Claim 13, Claim 1
In the thermal barrier coating member of the invention corresponding to any one of the above items 4, the MCrAlY alloy layer has an Al concentration on its surface of 10% or more.

According to the thermal barrier coating member of the invention corresponding to claim 15, the ACr on the surface of the MCrAlY alloy layer
By setting the 1 concentration to 10% or more, an Al-based protective film is formed on the surface of the MCrAlY alloy layer in contact with the corrosive oxidizing gas. Therefore, the absolute amount of corrosion oxidation is reduced, and MCrA
The stress acting on the partially stabilized zirconia layer is reduced due to volume expansion caused by the corrosion oxidation of the 1Y alloy layer, and cracking and peeling of the partially stabilized zirconia layer can be reduced.

[0044]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic sectional view showing a first embodiment of a thermal barrier coating member according to the present invention.

The thermal barrier coating member is made of Ni, Co,
Alternatively, an MCrAlY alloy layer 2 having excellent corrosion resistance and oxidation resistance and a partially stabilized zirconia (ZrO ₂₎ having low thermal conductivity and being chemically stable are formed on a metal base 1 of a superalloy excellent in high-temperature strength based on Fe. Main component: Y ₂ O ₃ , MgO, CeO
_In this case, two layers of Y ₂ O _{3 (} partially stabilized ZrO ₂ ) are formed. Here, the MCrAlY alloy layer 2 is a very dense one in which the ratio of the pores 4 (porosity) is 2% or less, and Y ₂ O ₃
The partially stabilized ZrO ₂ layer 3 is porous with a porosity of 5 to 60%.

Next, an example of a method for manufacturing the thermal barrier coating member shown in FIG. 1 will be described. The MCrAlY alloy layer 2 is
Combustion gas of hydrogen or hydrocarbon-based fuel (eg, CH ₄ ) and oxygen is a heat source, and raw material MCrAlY alloy powder is inserted into a thermal spray gun using high-pressure gas such as compressed air to melt the molten MCrAlY alloy particles. It is formed by spraying onto a metal substrate at high speed.

By using such a method, a very dense MCrAlY alloy layer is formed on the metal substrate. Further, after forming the MCrAlY alloy layer on the metal substrate,
By performing the heat treatment in a vacuum at a heating temperature of 700 ° C. to 1100 ° C. or in an inert gas atmosphere, a more dense MCrAlY alloy layer having high adhesion to a metal substrate can be obtained.

On the other hand, the Y ₂ O ₃ partially stabilized ZrO ₂ layer 3
Is a powder having a secondary particle diameter in the range of 50 to 100 μm.
% Or more of the partially stabilized zirconia hollow powder is supplied into a high-temperature plasma and melted, and the melt is placed on a plasma jet and sprayed at high speed onto a metal substrate.

By using such a method, a very porous Y ₂ O ₃ partially stabilized ZrO ₂ layer is formed on a metal substrate. Further, in order to make the Y ₂ O ₃ partially stabilized ZrO ₂ layer porous, a mixed powder with a powder that easily sublimates, such as carbon or an organic substance, was used, and a composite film with a metal or an inorganic compound was formed. Thereafter, a method of removing only the metal or the inorganic compound by acid, alkali, or heat evaporation and leaving it as pores is also effective.

Next, the operation of the thermal barrier coating member configured as described above will be described with reference to FIGS. Figure 2 is used as a thermal barrier ceramic layer Y ₂ O ₃ partially stabilized Zr
3 shows the relationship between the porosity of the O ₂ layer and the thermal conductivity. From this figure, it is clear that in the Y ₂ O ₃ partially stabilized ZrO ₂ layer, the thermal conductivity tends to decrease as the porosity increases (the porousness increases).

This indicates that the ability to block heat at the pores is even greater than the Y ₂ O ₃ partially stabilized ZrO ₂ layer of a typical low thermal conductivity material. That is, Y ₂ O
_{By making the three-} part stabilized ZrO ₂ layer porous, it is possible to further reduce the thermal conductivity.

Next, FIG. 3 shows the relationship between the porosity of the Y ₂ O ₃ partially stabilized ZrO ₂ layer and the fracture toughness value. Here, the fracture toughness value on the vertical axis was calculated from the crack length when Vickers indentation was made using the indentation method. From this figure, it is clear that the more tough the Y ₂ O ₃ partially stabilized ZrO ₂ layer, the greater the fracture toughness value.

The reason why the fracture toughness value increases as the material becomes more porous is considered to be because the pores effectively act to absorb the propagation energy of the crack. That is, Y ₂ O
_The fracture toughness can be improved by making the partially stabilized ZrO ₂ layer porous.

Next, FIG. 4 shows the increase in oxidation of the MCrAlY alloy layer in a high-temperature combustion gas atmosphere for improving the corrosion resistance and oxidation resistance of the metal substrate and the adhesion to the metal substrate.
Here, an MCrAlY alloy layer having a large porosity (5%)
And small porosity and dense MCrAlY alloy layer (1%)
The oxidation increase is compared for the two types. From this figure, it is clear that the increase in oxidation of the MCrAlY alloy layer is greatly affected by the porosity, and the larger the porosity, the greater the oxidation increase.

It is considered that this is because most of the pores of the MCrAlY alloy layer are open pores communicating with the outside, and the larger the porosity, the larger the area exposed to the high-temperature combustion gas.

On the other hand, FIG. 5 shows that MCrAlY changes to Al ₂ O ₃ due to oxidation of the MCrAlY alloy layer, and the stress in the peeling direction generated in the Y ₂ O ₃ partially stabilized ZrO ₂ layer due to volume expansion at that time is analyzed. I'm asking. Also, MCr
The interface between the AlY alloy layer and the Y ₂ O ₃ partially stabilized ZrO ₂ layer has irregularities of about 10 μm. From this figure, MC
As the amount of oxidation of the rAlY alloy layer increases, Y ₂ O ₃
It is clear that the maximum stress in the peeling direction generated in the partially stabilized ZrO ₂ layer also tends to increase.

Conversely, if the increase in the oxidation of the MCrAlY alloy layer is suppressed, the maximum stress in the peeling direction generated in the Y ₂ O ₃ partially stabilized ZrO ₂ layer can be reduced.
That is, in consideration of the result of the oxidation increase in the MCrAlY alloy layer with the changed porosity shown in FIG. 4, the smaller the porosity and the denser the MCrAlY alloy layer, the more Y ₂ O ₃
The maximum stress in the peeling direction generated in the partially stabilized ZrO ₂ layer can be reduced.

FIG. 6 is a schematic sectional view showing a second embodiment of the thermal barrier coating member according to the present invention. This thermal barrier coating member is made of Ni, Co, or F, as in FIG.
e-based superalloy metal substrate 1 with excellent high-temperature strength
On top, an MCrAlY alloy layer 2 having excellent corrosion resistance and oxidation resistance, and chemically stabilized Y ₂ O ₃ partially stabilized ZrO ₂ having low thermal conductivity.
It is formed from layer 3. Here, MCrAlY
Alloy layer 2, the proportion of the pores 4 (porosity) of 2% or less of the extremely dense, porous I Y ₂ O ₃ partially stabilized ZrO ₂ layer 3 which surface has a porosity of between 5% to 60% Y ₂ O ₃ partially stabilized ZrO ₂ layer unit and 5, the interfacial porosity is less than dense Y ₂ O ₃ portion of the MCrAlY alloy layer 2 stabilized Z
The rO ₂ layer 6 has a two-layer structure with different porosity.

Next, the operation of the thermal barrier coating member configured as described above will be described. As shown in FIG.
_{Since the} thermal conductivity can be reduced by making the ₂ O ₃ partially stabilized ZrO ₂ layer porous, the porosity on the surface side of the Y ₂ O ₃ partially stabilized ZrO ₂ layer can be increased to make the Y ₂ O ₃ partially stable. Chemical Z
If the entire rO ₂ layer is used, the thermal conductivity can be reduced.

Further, as shown in FIG. 3, the fracture toughness is improved by making the Y ₂ O ₃ partially stabilized ZrO ₂ layer porous. That is, for example, by porous surface side of producing rapid temperature changes such as during start-stop of the gas turbine Y ₂ O ₃ partially stabilized ZrO ₂ layer, applied a large thermal shock due to the rapid temperature change Y ₂ O ₃ Partially stabilized ZrO
Damage on the surface side of the _two layers can be reduced.

FIG. 7 is a schematic sectional view showing a third embodiment of the thermal barrier coating member according to the present invention. This thermal barrier coating member is made of Ni, Co, or F, as in FIG.
e-based superalloy metal substrate 1 with excellent high-temperature strength
On top, an MCrAlY alloy layer 2 having excellent corrosion resistance and oxidation resistance, and chemically stabilized Y ₂ O ₃ partially stabilized ZrO ₂ having low thermal conductivity.
It is formed from layer 3. Here, MCrAlY
The alloy layer 2 is very dense with a ratio of the pores 4 (porosity) of 2% or less.

On the other hand, the Y ₂ O ₃ partially stabilized ZrO ₂ layer 3 has a porous surface with an increased porosity,
The porosity in the Y ₂ O ₃ partially stabilized ZrO ₂ layer 3 is changed so that the porosity gradually increases toward the interface with the AlY alloy layer 2.

Next, the operation of the thermal barrier coating member configured as described above will be described. As shown in FIG.
_{Since the} thermal conductivity can be reduced by making the ₂ O ₃ partially stabilized ZrO ₂ layer porous, the porosity on the surface side of the Y ₂ O ₃ partially stabilized ZrO ₂ layer can be increased to make the Y ₂ O ₃ partially stable. Chemical Z
If the entire rO ₂ layer is used, the thermal conductivity can be reduced.

Further, as shown in FIG. 3, the fracture toughness is improved by making the Y ₂ O ₃ partially stabilized ZrO ₂ layer porous. That is, for example, results in a rapid temperature change, such as during start and stop of the gas turbine Y ₂ O ₃ portions as the surface side of the stabilized ZrO ₂ layer excellent in fracture toughness, high thermal shock due to the sudden change in temperature is applied Y ₂ Damage on the surface side of the O ₃ partially stabilized ZrO ₂ layer can be reduced.

FIG. 8 is a schematic sectional view showing a fourth embodiment of the thermal barrier coating member according to the present invention. This thermal barrier coating member is made of Ni, Co, or F, as in FIG.
e-based superalloy metal substrate 1 with excellent high-temperature strength
It is formed of a MCrAlY alloy layer 2 having excellent corrosion resistance and oxidation resistance, an alloy intermediate layer 7, and a chemically stabilized Y ₂ O ₃ partially stabilized ZrO ₂ layer 3 having low thermal conductivity. Here, the MCrAlY alloy layer 2 has a ratio of porosity 4 (porosity).
Is very dense, not more than 2%. Alloy intermediate layer 7
Is a layer containing Al of the oxidation-resistant element in a concentration ratio of 10% or more. The Y ₂ O ₃ partially stabilized ZrO ₂ layer 3 has a porosity of 5
It is a very porous material with a content of ６０60%.

Next, the operation of the thermal barrier coating member configured as described above will be described. As shown in FIG.
_Since the thermal conductivity can be reduced by making the ₂ O ₃ partially stabilized ZrO ₂ layer porous, the thermal conductivity of the entire Y ₂ O ₃ partially stabilized ZrO ₂ layer can be reduced.

Further, as shown in FIG. 3, the fracture toughness is improved by making the Y ₂ O ₃ partially stabilized ZrO ₂ layer porous. That is, for example, when a large thermal shock is applied due to a rapid temperature change such as when the gas turbine is started or stopped, Y
Damage to the ₂ O ₃ partially stabilized ZrO ₂ layer can be reduced.

Further, as shown in FIG. 4, the porosity is 2%.
By forming the following dense MCrAlY alloy layer, the increase in oxidation in a high-temperature combustion gas atmosphere is reduced, and the oxidation resistance is improved. Further, as shown in FIG. 9, by providing an alloy intermediate layer containing 10% or more of Al, which is an oxidation-resistant element, at a concentration ratio of 10% or more on the surface of the MCrAlY alloy layer, the increase in oxidation in a higher-temperature combustion gas atmosphere is reduced. Oxidation resistance is improved.

This is because Al ₂ O ₃ is dense in the high temperature combustion gas in the alloy intermediate layer and has a small volume diffusion coefficient of oxygen.
Is formed, preventing oxygen from entering the alloy,
This is because oxygen is suppressed. That is, MCrAlY
By using a thermal barrier coating having an alloy intermediate layer containing Al at a concentration ratio of 10% or more on the surface of the alloy layer, the increase in oxidation can be suppressed. As a result, MCrAlY as shown in FIG.
With the oxidation of the alloy layer and the alloy intermediate layer, the maximum stress in the peeling direction generated in the Y ₂ O ₃ partially stabilized ZrO ₂ layer can be reduced,
The peeling generated in the Y ₂ O ₃ partially stabilized ZrO ₂ layer can be reduced.

According to each embodiment of the present invention described above, the following effects can be obtained. First, in the first embodiment of the present invention, the heat shielding performance can be improved by the porous Y ₂ O ₃ partially stabilized ZrO ₂ layer having a porosity of 5 to 60%, as shown in FIG. It is clear from the relationship between the coefficient and the thermal conductivity.

Further, in FIG. 10, the effectiveness when the present thermal barrier coating member is applied to a high-temperature component of a gas turbine is compared with a conventional one. As a test method, a burner test in which heating / cooling is repeated by using LNG and air combustion gas simulating an operating environment is applied, and the peeling life of the coating is compared.

As shown in this figure, in the thermal barrier coating member,
It is clear that the thermal cycle peeling life is remarkably improved as compared with a conventional thermal barrier coating member composed of an MCrAlY alloy layer and a thermal barrier ceramic layer formed by plasma spraying in the atmosphere. The result is particularly large when the thickness of the thermal barrier ceramic layer is as thick as 1.0 mm.

Next, the effects of another embodiment of the present invention will be listed as follows. (1) Y ₂ by O ₃ partially stabilized ZrO ₂ layer a porous, model improves thermal barrier performance is a primary function as a thermal barrier ceramic layer, a thin barrier thermal barrier performance required in thermal ceramic layer thickness Can be satisfied. ₍₂₎ Y 2 O ₃ portions for toughness by a stabilized ZrO ₂ layer made porous is enhanced, Y ₂ O ₃ when the large thermal shock is applied by sudden temperature changes such as during start-stop of the gas turbine Cracking and peeling occurring in the partially stabilized ZrO ₂ layer can be reduced. (3) The surface is made of porous Y ₂ O ₃ partially stabilized ZrO ₂ having a large porosity, and the vicinity of the interface with the MCrAlY alloy layer has a porosity of Y ₂ O ₃ partially stabilized ZrO ₂ having a small porosity. the Y ₂ O ₃ partially stabilized ZrO ₂ layer consisting of two different layers, has a high strength in the vicinity of the interface at the fracture toughness and the MCrAlY alloy layer on the surface of start and stop time of such sudden changes in temperature of the gas turbine occurs. That is, in the Y ₂ O ₃ partially stabilized ZrO ₂ layer whose functions are separated by controlling the porosity, in order to achieve both thermal shock resistance and strength,
Cracking and peeling can be reduced. (4) surface is larger porous Y ₂ O ₃ partially stabilized ZrO ₂ layer porosity, low porosity toward the interface between the MCrAlY alloy layer, and Y ₂ O ₃ portion porosity is inclined In the stabilized ZrO ₂ layer, the fracture toughness on the surface where a sudden temperature change occurs, such as when the gas turbine starts and stops, and the MCr
MCr where large stress occurs near the interface with the AlY alloy layer
It has large strength near the interface with the AlY alloy layer. That is, Y whose functions are separated by controlling the porosity.
_{In the 2} O ₃ partially stabilized ZrO ₂ layer, cracking and peeling can be reduced in order to achieve both thermal shock resistance and strength. (6) The surface of the MCrAlY alloy layer is coated with the oxidation-resistant element Al.
For oxidation resistance is improved by the provision of the alloy interlayer comprising at least 10% at a concentration ratio, Y ₂ O ₃ partially stabilized Zr
The maximum stress in the peeling direction generated in the O ₂ layer can be reduced, and Y ₂ O
₍₃₎ Delamination occurring in the partially stabilized ZrO ₂ layer can be reduced.

[0074]

As described above, according to the present invention, the heat shielding performance and the durability can be improved, and the present invention is suitable as a high-temperature component used in a high-temperature oxidizing and corrosive atmosphere such as a gas turbine or a jet engine. A thermal barrier coating member and a method for manufacturing the same can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a first embodiment of a thermal barrier coating member according to the present invention.

FIG. 2 shows a partially stabilized Z ₂ O _{3 according to} the embodiment.
diagram showing the relationship between the porosity and thermal conductivity of and rO ₂ layers.

[FIG. 3] In the embodiment, Y ₂ O ₃ partially stabilized Z
diagram showing the relationship between the porosity and the fracture toughness value of and rO ₂ layers.

FIG. 4 is a view showing the MCr having different porosity in the embodiment.
The figure which compared the oxidation increase in high-temperature combustion gas atmosphere about two types of thermal barrier coding members comprised by the AlY alloy layer.

FIG. 5 is a view showing stress in a peeling direction generated in a Y ₂ O ₃ partially stabilized ZrO ₂ layer due to volume expansion accompanying growth of an MCrAlY alloy layer in a thermal barrier coding member in the embodiment.

FIG. 6 is a schematic sectional view showing a second embodiment of the thermal barrier coating member according to the present invention.

FIG. 7 is a schematic sectional view showing a third embodiment of the thermal barrier coating member according to the present invention.

FIG. 8 is a schematic sectional view showing a fourth embodiment of the thermal barrier coating member according to the present invention.

FIG. 9 shows an increase in oxidation in a high-temperature combustion gas atmosphere of two types of thermal barrier coating members in a case where an alloy intermediate layer having a high Al concentration is present on the surface of an MCrAlY alloy layer and in a case where no alloy intermediate layer is present. FIG.

FIG. 10 is a diagram for explaining an effect of each embodiment of the thermal barrier coating member according to the present invention in comparison with a conventional example, and comparing thermal cycle peeling life by a burner rig test apparatus.

[Explanation of symbols]

1 ...... metal substrate 2 ...... MCrAlY alloy layer 3 ...... Y ₂ O ₃ partially stabilized ZrO ₂ layer 4 ...... pores 5 ...... porous Y ₂ O ₃ partially stabilized ZrO ₂ layer 6 ...... dense a Y ₂ O ₃ partially stabilized ZrO ₂ layer 7 ...... alloy intermediate layer

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Keizo Honda 2-4, Suehirocho, Tsurumi-ku, Yokohama-shi, Kanagawa Prefecture Inside Keihin Works, Toshiba Corporation (72) Masako Nakahashi 2-chome, Suehirocho, Tsurumi-ku, Yokohama-shi, Kanagawa 4 Toshiba Keihin Works Co., Ltd.

Claims (15)

[Claims] 1. An MCrAlY alloy (M: N) on a metal substrate.
i, Co, Fe or an alloy thereof) and a partially stabilized zirconia layer, wherein the partially stabilized zirconia layer has a porosity of 5 to 60%. Characterized thermal barrier coating member. 2. An MCrAlY alloy (M: N) on a metal substrate.
i, Co, Fe or an alloy comprising a combination of these elements) and a partially stabilized zirconia layer, wherein the partially stabilized zirconia layer has a porosity of 10 to 30%. Characterized thermal barrier coating member. 3. An MCrAlY alloy (M: N) on a metal substrate.
i, Co, Fe or an alloy combining these elements) layer, and the secondary particles have a particle diameter of 50 to 100 μm.
95% or more, and the filling ratio of primary particles is 70%.
% Of an oxide-based ceramic raw material powder having a high porosity and a high-porosity partially-stabilized zirconia layer. A method for producing a thermal barrier coating member, comprising: 4. An MCrAlY alloy (M: N) on a metal substrate.
i, Co, Fe or an alloy comprising a combination of these elements) and a mixture of an oxide-based ceramic and a material A that sublimes in a high-temperature atmosphere, such as carbon or an organic substance, is used as a raw material powder. Supplying a raw material powder into a high-temperature atmosphere and spraying a molten oxide ceramic onto the MCrAlY alloy layer while sublimating the material A to form a partially stabilized zirconia layer having a high porosity; A method for producing a thermal barrier coating member. 5. An MCrAlY alloy (M: N) on a metal substrate.
i, Co, Fe or an alloy of these elements) forming a layer, and using a mixture of an oxide-based ceramic and a metal or an inorganic compound having a higher vapor pressure than the oxide-based ceramic as a raw material powder, The raw material powder is supplied and melted in a high-temperature atmosphere, and is sprayed at a high speed onto the MCrAlY alloy layer, so that the oxide-based ceramic and the metal are melted.
Or a thermal barrier coating member comprising a step of forming a partially stabilized zirconia layer having a high porosity by removing a metal or an inorganic compound by evaporation at a high temperature after forming a mixed film of an inorganic compound. Manufacturing method. 6. An MCrAlY alloy (M: N) on a metal substrate.
i, Co, Fe or an alloy which combines these elements) layer, and using a mixture of an oxide-based ceramic and a metal as a raw material powder, supplying the raw material powder into a high-temperature atmosphere, and melting the raw material powder. A step of spraying the MCrAlY alloy layer at a high speed to form a mixed film of an oxide ceramic and a metal, and then dissolving and removing only the metal with an acid or an alkali to form a partially stabilized zirconia layer having a high porosity. A method for producing a thermal barrier coating member, comprising: 7. An MCrAlY alloy (M: N) on a metal substrate.
i, Co, Fe or an alloy thereof) and a partially stabilized zirconia layer, wherein the partially stabilized zirconia layer has a porosity of 5 to 60% on the coating surface side. A partially stabilized zirconia layer portion having a porosity closer to the interface with the MCrAlY alloy layer and a partially stabilized zirconia layer portion having a denser porosity than the coating surface side. A thermal barrier coating member, characterized in that: 8. An MCrAlY alloy (M: N) on a metal substrate.
i, Co, Fe or an alloy thereof) and a partially stabilized zirconia layer, wherein the partially stabilized zirconia layer has a porosity of which the coating surface is porous, MCrAlY
A thermal barrier coating member formed by gradually changing the interface side with the alloy layer to be dense. 9. The method for producing a thermal barrier coating member according to claim 3, wherein the oxide-based ceramic raw material powder is obtained by changing the particle size of the secondary particles or the packing ratio of the primary particles. A method for producing a thermal barrier coating member, wherein the porosity of the layer is changed. 10. The method for manufacturing a thermal barrier coating member according to claim 4, wherein the raw material powder is prepared by changing a mixing ratio of an oxide-based ceramic and a material A, such as carbon or an organic substance, which sublimes in a high-temperature atmosphere. A method for producing a thermal barrier coating member, wherein the porosity of the stabilized zirconia layer is changed. 11. The method for manufacturing a thermal barrier coating member according to claim 5, wherein a raw material powder in which a mixing ratio of an oxide ceramic and a metal having a higher vapor pressure than the oxide ceramic or an inorganic compound is changed. Characterized in that the porosity of the partially stabilized zirconia layer has been changed by heating. 12. The method for manufacturing a thermal barrier coating member according to claim 6, wherein the porosity of the partially stabilized zirconia layer is changed by using a raw material powder in which a mixing ratio of an oxide ceramic and a metal is changed. A method for producing a thermal barrier coating member. 13. An MCrAlY alloy (M:
Ni, Co, Fe or alloys combining these elements)
In a thermal barrier coating member comprising a layer and a partially stabilized zirconia layer, the partially stabilized zirconia layer has a porosity of 5 to 60%, and the MCrAlY alloy layer has a porosity of 2% or less. Characterized thermal barrier coating member. 14. An MCrAlY alloy (M:
Ni, Co, Fe or alloys combining these elements)
In a thermal barrier coating member comprising a layer and a partially stabilized zirconia layer, the partially stabilized zirconia layer has a porosity of 10 to 30%, and the MCrAlY alloy layer has a porosity of 2% or less. Characterized thermal barrier coating member. 15. The thermal barrier coating member according to any one of claims 1, 2, 7, 8, 13, and 14, wherein the MCrAlY alloy layer has a surface. A thermal barrier coating member having an Al concentration of 10% or more.