JPH09310168A - Heat resistant member and production of heat resistant member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress deterioration caused by oxidation, corrosion or the like in a metallic substrate accompanying the depletion, damage or the like of an MCrAlY alloy layer in the case of being used for a long time in a high temp. atmosphere. SOLUTION: An MCrAlY alloy layer 2 (M denotes at least one kind of element selected from Ni, Co and Fe) is formed on a metallic substrate 1 composed of an alloy essentially consisting of at least one kind selected from Ni, Co and Fe by coating. The surface of this MCrAlY alloy layer is coated with a ceramics layer 3 having 1 to 50μm average thickness. This ceramics layer 3 is composed of a primary ceramics layer 4 essentially consisting of alumina and formed on the MCrAlY alloy layer and a secondary ceramics layer 5 consisting of oxide ceramics (excluding alumina) having oxygen dissociating performance in a low oxygen atmosphere and working as an oxygen feeding source at the time of forming the primary ceramics layer 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-resistant member suitable for a material which is required to have high-temperature strength, oxidation resistance, corrosion resistance and the like for a long time under a high temperature environment, and a method for producing the same.

[0002]

2. Description of the Related Art The metal members constituting a heat engine such as a gas turbine, an aircraft engine, an automobile engine, etc. are made of Ni or Co as a main component in consideration of high temperature strength, oxidation resistance and high temperature corrosion resistance. Alloys are used as substrates. In particular, in gas turbine and aircraft engine dynamic and stationary blades where the operating environment temperature exceeds 1273K, in order to suppress deterioration due to oxidation of the metal base material made of superalloy, especially strength reduction due to thinning and wear. , MCrAlY (M: Ni, Co, Ni
Co, CoNi, Fe, etc.) alloy layers called "alloy layers" are formed on a metal base material, and an Al-enriched layer is further formed thereon.

As described above, the surface of a metal base material has been conventionally coated with an MCrAlY alloy layer or an Al-rich layer for the purpose of suppressing the reduction in strength and wear due to the thinning of the metal base material. However, conventional MCrAlY alloy layer and Al
The heat-resistant member coated with the enriched layer has the following problems when used for a long time in a high temperature environment.

That is, when the MCrAlY alloy layer is used for a long time in a high temperature atmosphere, the surface of the MCrAlY alloy layer is oxidized, and alumina, transition metal oxides (nickel oxide, cobalt oxide, etc.), Al
An oxide such as a complex oxide (spinel) of a transition metal and a transition metal is generated. Of these, if an oxide layer containing a large amount of nickel oxide or cobalt oxide is generated, a void is generated at the interface between the oxide layer and the MCrAlY alloy layer, and the oxide layer is likely to peel off. Therefore, when used for a long time in a high temperature environment, an oxide layer is always formed on the surface of the MCrAlY layer, and the peeling and regeneration are repeated. As a result, the MCrAlY alloy layer is worn or damaged, and there is a problem that the function of suppressing deterioration of the metal base material due to oxidation or the like cannot be maintained for a long time.

Therefore, in order to develop a long-life oxidation-resistant coating, formation of oxides of transition metals such as Ni and Co should be suppressed as much as possible, and a stable and dense coating in a high temperature atmosphere should be resistant to oxidation. It is desired to produce an oxide layer consisting mainly of alumina that can be used as a protective film. But,
When the MCrAlY alloy layer is simply oxidized in a high temperature atmosphere,
In addition to alumina, a plurality of oxides such as transition metal oxides and composite oxides are formed, and it is impossible to form a dense and uniform alumina layer.

Further, the metal members constituting the gas turbine, the engine, etc. may be used in an oxidizing atmosphere and in a highly corrosive environment containing S, V and the like. In such a case, by forming an oxide layer mainly containing chromia or a composite oxide of Al and Cr on the MCrAlY alloy layer rather than an oxide layer mainly containing alumina, S and V
It is known that the corrosion resistance against the like is improved. However, under the present circumstances, since oxides of transition metals such as Ni and Co are simultaneously formed at the same time as chromia, dense chromia and A
It is not possible to form an oxide layer mainly composed of a complex oxide of 1 and Cr. Therefore, when used in a high temperature corrosive environment for a long time, MCrA may enter due to the intrusion of corrosive substances such as S and V.
There is a problem that the deterioration of the LY alloy layer occurs and the deterioration suppressing function of the metal base material cannot be maintained for a long time.

Further, an oxidation resistant structure has been proposed in which an Al-enriched layer is formed directly on the MCrAlY alloy layer to prevent wear of the base material even when oxides are formed or peeled off. Basically, oxidation and peeling occur repeatedly, so the effect of suppressing the oxidation of the substrate is not sufficient. On the other hand, if it is used for a long time, elemental diffusion occurs due to the difference in composition between the Al-rich layer and the MCrAlY alloy layer, and an embrittlement phase or a void is generated in the coating layer, so that the coating layer easily peels off. However, due to the inward diffusion of Al, the amount of Al element decreases in the vicinity of the outer surface and it becomes difficult to maintain the oxidation resistance.

A metal base material composed of a superalloy of Ni or Co and M
Also at the interface with the CrAlY alloy layer, when used in a high temperature atmosphere for a long time, the diffusion of the component elements due to the difference in these compositions occurs, the strengthening phase of the metal base material disappears, and the embrittlement phase is generated. There are problems such as happening. Therefore, formation of a diffusion barrier layer that suppresses element transfer between the metal base material and the MCrAlY alloy layer has been studied.

Conventionally, as the diffusion barrier layer as described above, oxides, nitrides, oxynitrides, etc. containing Al or the like having a small diffusion coefficient of elements inside as a main component are formed by a film forming method such as a CVD method. However, the adhesion at the interface between the diffusion barrier layer formed by the CVD method or the like and the metal substrate or the MCrAlY alloy layer is poor, and peeling easily occurs at these interfaces. The peeling at the interface is a factor of shortening the life of the heat resistant member.

On the other hand, in the flow of higher temperature, MCrAlY is used as an oxidation / corrosion resistant coating on a metal substrate.
It is also considered to coat the ceramic layer with a thickness of about 200 to 300 μm as a thermal barrier coating on top of the alloy layer coating, but if it is used for a long time, it may occur at the interface between the ceramic coating layer and the metal coating layer. Oxidation occurs, C
An oxide layer containing an oxide of a transition metal such as o or Ni or a complex oxide is generated. Therefore, there is a problem that peeling occurs in the ceramic coating layer or the oxide layer, and the effect of suppressing the oxidation resistance of the metal base material by the metal coating layer is impaired.

[0011]

As described above, the conventional MCrAlY alloy layer and the heat-resistant member coated with the Al-enriched layer have the same MC content when used for a long time in a high temperature environment.
An oxide layer containing an oxide of a transition metal such as Ni or Co is formed on the surface of the rAlY alloy layer, etc., which causes peeling of the MCrAlY alloy layer, etc., so that oxidation and strength reduction of the metal base material are sufficiently suppressed. There is a problem that you cannot do it. In addition, even at the interface between the metal base material and the MCrAlY alloy layer, when used in a high temperature environment for a long time, component elements diffuse, which causes a problem that the strength of the metal base material is reduced.

From the above, in the conventional heat resistant member to which the metal coating is applied, the Ni of the MCrAlY alloy layer is
Oxidation accompanied by the formation of oxides of transition metals such as Co and Co, and element diffusion at the interface between the metal base material and the MCrAlY alloy layer, thereby suppressing oxidation and strength reduction of the metal base material for a long time. That is a challenge. The present invention has been made to address such a problem, and suppresses peeling of an oxide layer formed on the MCrAlY alloy layer for a long time, or at the interface between the metal base material and the MCrAlY alloy layer. It is an object of the present invention to provide a heat-resistant member in which the characteristics of a metal base material are maintained for a long time and a long life is achieved by suppressing element diffusion, and a manufacturing method thereof.

[0013]

The first heat-resistant member according to the present invention is, as described in claim 1, a metal base material made of an alloy containing at least one selected from Ni, Co and Fe, and MCrA coated on a metal substrate
1Y alloy layer (where M represents at least one element selected from Ni, Co and Fe) and MCrA
a ceramic layer having an average thickness of 1 to 50 μm provided on the LY alloy layer, the ceramic layer being the MCr.
A first ceramics layer mainly made of alumina formed on the AlY alloy layer and a second ceramics oxide (excluding alumina) having oxygen dissociation ability existing on the first ceramics layer. It is characterized by having a ceramics layer.

The method of manufacturing the heat-resistant member of the present invention is N
An MCrAlY alloy layer (where M represents at least one element selected from Ni, Co and Fe) is formed on the surface of a metal base material made of an alloy containing at least one selected from i, Co and Fe. Process and the MC
The step of forming an oxide ceramic layer having oxygen dissociation ability (excluding alumina) on the surface of the rAlY alloy layer by a thermal spraying method and the metal base material on which the oxide ceramic layer is formed are And a heat treatment step under a temperature condition of 1373 K or higher in an oxygen atmosphere.

The second heat-resistant member according to the present invention comprises, as described in claim 3, a metal base material made of an alloy containing at least one selected from Ni, Co and Fe, and directly on the metal base material. Or a ceramics layer formed by coating via an Al-enriched layer, the ceramics layer being mainly composed of at least one selected from alumina and chromia formed on the metal substrate or the Al-enriched layer. It is characterized by having one ceramic layer and a second ceramic layer formed on the first ceramic layer and made of oxide ceramics having oxygen dissociation ability (excluding alumina and chromia).

According to another aspect of the present invention, there is provided another heat resistant member.
As described above, a metal base material made of an alloy containing at least one selected from Ni, Co and Fe, and an oxygen diffusion layer or a surface oxidation layer provided on the surface portion of the metal base material, or the metal base material. Surface oxide layer provided on the Al-enriched layer formed on the material, and the MCrAlY alloy layer formed by coating on the metal base material or the Al-enriched layer through the oxygen diffusion layer or the surface oxide layer (however, , M is Ni, Co
And at least one element selected from Fe)
Are provided.

In the first heat-resistant member of the present invention, the MCrAlY alloy layer and the MCrAlY alloy layer are formed by heat-treating the second ceramics layer made of oxide-based ceramics having oxygen dissociation ability during or after the film formation. At the interface with the second ceramics layer, the first layer consisting mainly of alumina
Since the ceramics layer is formed, the generation of oxides of transition metals such as Ni and Co and their complex oxides, which cause exfoliation due to oxidation of the MCrAlY alloy layer, is suppressed. Therefore, the wear and damage of the MCrAlY alloy layer are suppressed, which can suppress the oxidation and strength decrease of the metal base material, and further, the thickness of the ceramic layer is set in an appropriate range. The effect can be stably maintained for a long time.

In the second heat-resistant member, a second ceramics layer is formed on the metal base material directly or via the Al-rich layer, and the second ceramics layer and the metal base material or the Al-rich layer are formed. Since the first ceramics layer mainly made of alumina or chromia is formed at the interface of, it is possible to improve the oxidation resistance and corrosion resistance of the metal base material, and furthermore, the thickness of the ceramics layer is within the proper range. To
It becomes possible to stably maintain the above-mentioned oxidation resistance and corrosion resistance for a long time. Furthermore, it is possible to eliminate the disappearance of the strengthening phase and the formation of the embrittlement phase of the metal base material that may occur when the metal coating layer is formed, and it is possible to prevent the strength of the base material from decreasing due to these.

In the other heat-resistant member of the present invention, the oxygen diffusion layer provided on the surface of the metal substrate is subjected to heat treatment during preliminary heat treatment or during actual use, so that alumina or alumina and alumina, Ni, Co, Cr, etc. To form a complex oxide. This oxide layer functions as a diffusion barrier layer that suppresses mass transfer between the metal base material and the ΜCrAlY alloy layer, and is superior to the metal base material and the MCrAlY alloy layer because it is a material generated by an interfacial reaction. Has adhesion. Therefore, peeling or the like caused by the diffusion barrier layer can be suppressed. In addition, the surface oxidation layer of the metal base material or the Al-enriched layer is also the same as the metal base material and ΜCrA.
It functions as a diffusion barrier layer that suppresses the mass transfer between the 1Y alloy layers and has excellent adhesion to the metal base material or the Al-rich layer.

[0020]

Embodiments of the present invention will be described below.

FIG. 1 is a sectional view schematically showing the structure of one embodiment of the heat-resistant member of the present invention. In the figure, reference numeral 1 denotes a metal base material, and as the metal base material 1, a heat-resistant alloy containing at least one selected from Ni, Co and Fe as a main component is used. A heat resistant alloy can be appropriately selected and used. Practically I
N738, IN738LC, IN939, Μar-Μ2
47, RENE80, CM-247, CMSX-2, C
Ni-based superalloys such as MSX-4, FSX-414,
It is effective to use a Co-based superalloy such as Mar-M509.

On the above-mentioned metal substrate 1, a ΜCrAlY alloy layer (M represents at least one element selected from Ni, Co and Fe) 2 as a corrosion and oxidation resistant metal coating.
Is coated. The ΜCrAlY alloy layer 2 is generally 0.1 to 20% by weight of Al, 10 to 35% by weight of Cr, and 0.1 to 5% by weight of Y in order to obtain a function as a corrosion / oxidation resistant metal coating. An alloy having a composition substantially containing at least one M element selected from the group consisting of Ni, Co and Fe is used.
rAlY alloy, CoNiCrAlY alloy, NiCrAl
Examples include Y alloys, CoCrAlY alloys, FeCrAlY alloys, and the like. Depending on the application, it is possible to add a small amount of at least one additive element selected from Ti, Nb, Hf, Zr, Ta and W to the MCrAlY alloy within a range of 5% by weight or less.

The thickness of the above-mentioned ΜCrAlY alloy layer 2 is 50.
It is preferable to set the thickness to about 300 μm from the viewpoint of the oxidation life and the stress relaxation effect. Further, as a method of forming the ΜCrAlY alloy layer 2, a thermal spraying method, a PVD method, a sputtering method, C
VD method and the like. In particular, in the thermal spraying method, it is preferable to apply a reduced pressure spraying method or an HVOF method that can obtain a denser coating layer than the atmospheric spraying method. According to these methods, the internal oxidation of the MCrAlY alloy layer 2 by the entrained oxygen during the coating layer formation is further preferable. Can be suppressed.

Further, on the above-mentioned MCrAlY alloy layer 2, a ceramic layer 3 having an average thickness in the range of 1 to 50 μm is formed.
Is coated. The ceramic layer 3 is MCrA
The first ceramic layer 4 mainly made of alumina formed on the 1Y alloy layer 2 and the second ceramic layer 5 made of oxide-based ceramics excluding alumina existing on the first ceramic layer 4 are provided. The heat-resistant member 6 of the embodiment is constituted by these. The first ceramics layer 4, which is mainly made of alumina, is a ceramics layer which is usually composed of the constituent elements in the MCrAlY alloy layer 2 and the constituent elements in the second ceramics layer 5, and 50% by weight or more of which is alumina. The amount of alumina in the first ceramics layer 4 is preferably 75% by weight or more, more preferably 95% by weight or more.

Here, of the above-mentioned ceramic layers 3, the second ceramic layer 5 is made of an oxide ceramic material having oxygen dissociation ability in a low oxygen atmosphere (low oxygen potential). By performing heat treatment in the film formation process of 5 or after forming the second ceramic layer 5, the first ceramic layer 4 mainly made of alumina is formed at the interface between the MCrAlY alloy layer 2 and the second ceramic layer 5. It is formed. That is, an oxide-based ceramic material having oxygen dissociation ability in a low oxygen atmosphere is used as the second ceramic layer 5, and film formation or heat treatment is applied under the conditions described in detail later, whereby the MCrAlY alloy layer 2 is formed. Al among the components of
The first ceramic layer 4 made of oxide of MCrAl
It can be selectively formed at the interface between the Y alloy layer 2 and the second ceramic layer 5, and the obtained first ceramic layer 4 can be densified.

If the first ceramic layer 4 is too thick, peeling or the like due to the difference in the coefficient of thermal expansion from the MCrAlY alloy layer 2 is likely to occur, so that the surface of the MCrAlY alloy layer 2 can be uniformly covered. The thinner the better, specifically the average thickness is preferably 3.5 μm or less. Also,
If the average thickness of the first ceramics layer 4 is less than 0.01 μm, the uniform coating property of the surface of the MCrAlY alloy layer 2 is deteriorated, and it is preferable to set it to 0.1 μm or more in practical use.

As the oxide-based ceramic material for the second ceramic layer 5, a material that easily dissociates oxygen under a low oxygen potential is preferable, and one having a higher oxygen dissociation ability than alumina is particularly preferable. Specifically, zirconia,
1/8 oxygen from stabilized zirconia, titanium oxide, hafnium oxide, thorium oxide, rare earth metal oxides, molybdenum oxide, niobium oxide, tantalum oxide, alkaline earth metal oxides, their complex oxides and fluorite structure. Only ceramics with a bycrore structure that are regularly removed are used. Among these, stabilized zirconia is a particularly preferable material because it has a coefficient of thermal expansion close to that of a metal member, is a high melting point material, and is excellent in high temperature stability.

As described above, by forming the dense first ceramics layer 4 mainly made of alumina on the surface side of the MCrAlY alloy layer 2, diffusion of transition metal such as Co or Ni from the MCrAlY alloy layer 2 is achieved. Is suppressed. That is, the oxidation of the transition metal such as Co and Ni which is the cause of the exfoliation of the MCrAlY alloy layer 2 is suppressed, and the oxide of the transition metal such as Co and Ni or the composite oxide thereof is generated even when used for a long time. MCrAlY alloy layer 2
It is possible to suppress wear and tear of the. This gives M
The deterioration suppressing function expected by the CrAlY alloy layer 2 due to oxidation of the metal base material 1 is maintained for a long time, and the oxidation resistance of the metal base material 1 can be improved.

Further, the first ceramics layer 4 can be made into xAl ₂ O ₃ · yY ₂ O ₃ by appropriately setting the substrate temperature condition and the heat treatment condition at the time of film formation, as described later in detail.
A composite oxide of Al and Y, such as YAG or YAM, can be included. Since the composite oxide of Al and Y has a larger diffusion suppressing effect, the wear and damage of the MCrAlY alloy layer 2 caused by the formation of the oxide of the transition metal such as Co and Ni or the composite oxide thereof is further enhanced. It can be effectively suppressed.

Here, the second ceramics layer 5 is the first ceramics layer 4 when used for a long time in a high temperature atmosphere.
Although it has a function of suppressing the growth of Al, it is basically used to form the dense first ceramic layer 4 mainly made of alumina. It is different. Therefore, the second
The thickness of the ceramics layer 5 is equal to that of the first ceramics layer 4
It is sufficient if the second ceramics layer 5 is thick enough to supply oxygen necessary for forming
The formation of the first ceramics layer 4 becomes excessive, which causes the above-mentioned inconvenience. Therefore, the thickness of the second ceramic layer 5 is 50 μm or less as the average thickness of the ceramic layer 3 including the first ceramic layer 4.

That is, the average thickness of the ceramics layer 3 is
When it exceeds 50 μm, when the first ceramics layer 4 is formed by heat treatment after forming the second ceramics layer 5, the supplied oxygen amount becomes excessive and the first ceramics layer 4 becomes too thick. . When the first ceramics layer 4 is formed at the same time as the second ceramics layer 5 is formed, the first ceramics layer 4 is formed by heating the substrate, as will be described later in detail. If the thickness exceeds 50 μm, in other words, if the film formation time of the second ceramics layer 5 becomes too long, the heat treatment effect at the time of film formation increases, and the first ceramics layer 4 becomes too thick. This causes the inconvenience. However, if the thickness of the ceramic layer 3 is too thin, it becomes difficult to form the oxide layer as a dense coating, so the average thickness of the ceramic layer 3 is set to 1 μm or more.

The average thickness of the ceramics layer 3 is important not only for controlling the amount of the first ceramics layer 4 produced, but also for preventing the peeling of itself and the destruction within the layer. From this point as well, the average thickness of the ceramic layer 3 must be 50 μm or less. That is, when the average thickness of the ceramic layer 3 exceeds 50 μm, MCrAlY
Due to the thermal stress generated due to the difference in the coefficient of thermal expansion from the alloy layer 2, as well as the decrease in the strength of the alloy layer itself and the increase in the fracture origin,
The ceramic layer 3, that is, the second ceramic layer 5 is likely to be peeled off, cracked, or the like. Second ceramic layer 5
When peeling or cracking occurs in the first ceramic layer 4, naturally, peeling or the like easily occurs in the first ceramics layer 4, and it becomes impossible to suppress the above-described oxidation of the transition metal such as Co or Ni. From this point of view, it is desirable that the average thickness of the ceramics layer 3 is 30 μm or less, which can obtain a better effect of suppressing peeling and cracking.

As described above, in the present invention, it is important that the average thickness of the ceramics layer 3 is 50 μm or less, and this is the first time that good and stable oxidation of transition metals such as Co and Ni in the MCrAlY alloy layer 2 is achieved. It is possible to obtain the suppressing effect, and eventually the stable oxidation resistance of the metal substrate 1.

Further, when used in a more severe high temperature environment in which the oxidation reaction particularly progresses violently, as shown in FIG. 2, an Al-rich layer is further formed on the MCrAlY alloy layer 2 by an aluminum pack method or the like. 7 may be formed, and the ceramics layer 3 may be formed on the Al-enriched layer 7 to form the first ceramics layer 4 mainly made of alumina.

In the above embodiment, the case where the first ceramics layer is mainly composed of alumina has been described. However, as will be described later in detail, by appropriately setting the substrate temperature condition and the heat treatment condition during film formation, As shown in FIG. 3, a first ceramic layer 8 containing chromia in addition to alumina, for example, a first ceramic layer 8 mainly composed of a mixed oxide of chromia and alumina or a complex oxide of chromia and alumina. You can also do it. This first ceramics layer 8 is similar to the above-mentioned first ceramics layer 4 mainly made of alumina, and is usually made of MC.
The ceramic layer is composed of the constituent elements in the rAlY alloy layer 2 and the constituent elements in the second ceramic layer 5, and 50% by weight or more of which is alumina or chromia. The amount of alumina or chromia in the first ceramic layer 8 is preferably 75% by weight or more, more preferably 95% by weight or more.

Considering only the oxidation resistance of the metal base material 1, it is preferable that the first ceramic layer is a layer 4 mainly made of alumina, but it is used in an environment with high corrosiveness including S and V. In this case, it is preferable to form the first ceramic layer 8 mainly composed of a mixed oxide of chromia and alumina and a complex oxide of chromia and alumina. As a result, the heat resistant member 9 having excellent corrosion resistance and oxidation resistance can be obtained.

In this case, the thickness of the first ceramic layer 7 which is mainly composed of a mixed oxide of chromia and alumina, and a composite oxide of chromia and alumina, and the ceramic layer 3
The conditions such as the thickness are the same as those in the above-described embodiment.

The ceramic layer 3 in the heat-resistant members 6 and 9 of each of the above-mentioned embodiments can be formed, for example, as follows. First, a method for forming the first ceramics layers 4 and 8 by performing heat treatment after forming the second ceramics layer 5 will be described. In this method, FIG.
As shown in, the second ceramic layer 5 is formed on the MCrAlY alloy layer 2 by the PVD method, the thermal spraying method, or the like. When the second ceramics layer 5 is formed by the thermal spraying method or the PVD method, the substrate is heated to 973K or less. As the thermal spraying method, there is a plasma thermal spraying method, but even if a ceramic layer containing oxygen vacancies is formed by thermal spraying in a reduced pressure atmosphere for the purpose of reducing the amount of oxygen in the second ceramics layer 5 serving as an oxygen supply source. Good.

Next, the second ceramics layer 5 is heat-treated in a low oxygen atmosphere so that the interface between the MCrAlY alloy layer 2 and the second ceramics layer 5 is formed as shown in FIG. 4 (b). , The first ceramic layers 4 and 8 are formed. Thus, the second ceramics layer 5 is heat-treated in a low oxygen atmosphere, and oxygen is supplied from the second ceramics layer 5 to form the first ceramics layers 4 and 8 as a product of the interfacial reaction. By this, dense alumina or chromia can be selectively obtained.

The heat treatment atmosphere for forming the first ceramic layers 4 and 8 is preferably a vacuum of 1 Pa or less. If the degree of vacuum at the time of heat treatment exceeds 1 Pa, oxygen in the atmosphere may cause oxidation in the MCrAlY alloy layer 2. As a result, there is a possibility that oxides of transition metals such as Ni and Co that may cause the peeling of the MCrAlY alloy layer 2 may be generated. The heat treatment is more preferably performed in a low pressure atmosphere of 0.1 to 10 ⁻⁴ Pa, which can more effectively suppress the oxidation in the MCrAlY alloy layer 2.

The heat treatment temperature is selected depending on the components forming the first ceramics layer, and when the first ceramics layer 4 mainly made of alumina is formed, 107
It is preferably 3K or more. If the heat treatment temperature is less than 1073K, the amount of oxides other than alumina may increase. At this time, in particular, by setting the heat treatment temperature to 1373 K or higher, the first ceramics layer 4 can contain the composite oxide of Al and Y, as described above,
It is possible to more effectively suppress the production of oxides of transition metals such as Co and Ni. The heat treatment time is not particularly limited, but it is preferably about 1 to 100 hours. Note that this heat treatment may be performed as one step of a multi-step heat treatment (solution treatment + aging treatment) performed for maintaining the characteristics of the metal substrate 1.

On the other hand, when forming the first ceramics layer 8 mainly composed of a mixed oxide of chromia and alumina and a complex oxide of chromia and alumina, the heat treatment temperature should be in the range of 973 to 1073K. preferable. If the heat treatment temperature is less than 973K, the amount of oxides produced will be insufficient, while if it exceeds 1073K, the amount of alumina produced will increase and the amount of chromia will decrease. The first ceramics layer 8 may be a layer mainly made of chromia by controlling the heat treatment temperature at this time. Since this heat treatment temperature is lower than the multi-step heat treatment temperature performed for maintaining the characteristics of the metal base material 1 described above, the multi-step heat treatment described above is performed before the heat treatment for forming the first ceramics layer 8. carry out. Although the heat treatment time is not particularly limited,
It is preferably about 100 hours.

Next, a method of forming the first ceramics layer 4 simultaneously with the formation of the second ceramics layer 5 will be described.

In this method, the second ceramic layer 5 for dissociating oxygen in the low oxygen atmosphere described above is formed on the MCrAlY alloy layer 2 by the PVD method, the sputtering method, the CVD method or the like in the low oxygen atmosphere. To do. Simultaneously with the film formation in the low oxygen atmosphere, oxygen dissociated from the second ceramic layer 5 forms the dense first ceramic layer 4 mainly made of alumina on the surface of the MCrAlY alloy layer 2. In this case, the lower the oxygen potential, the more desirable. For example, the degree of vacuum is preferably 1 Pa or less. Further, if it is 0.1 Pa or less, the denser first ceramics layer 4 is formed at the interface with the MCrAlY alloy layer 2, which is more preferable.

Further, in the PVD method or the like, the first ceramics layer 4 mainly made of alumina cannot be formed only by coating the second ceramics layer 5 on the MCrAlY alloy layer 2, so that the metal base material 1 is formed. The second ceramics layer 5 is formed while heating. The heating temperature is preferably 973K or higher. If the heating temperature is less than 973K, it may be difficult to form a uniform oxide layer. Furthermore, if the heating temperature is 1123K or higher, it will be dense and MCrAl
It is more preferable because an oxide layer having excellent adhesion to the Y alloy layer 2 can be formed. Furthermore, it is desirable to coat while heating above 1173K.
Since the first ceramics layer 4 made of only coarse alumina having a particle diameter of about 0.2 to 0.5 μm is formed directly on the rAlY alloy layer 2, the diffusion of oxygen can be suppressed, so that a better effect of suppressing the oxidation reaction can be obtained. Can be expected.

In each of the above-described embodiments, the case where the ceramic layer 3 is formed on the MCrAlY alloy layer 2 has been described, but the ceramic layer 3 according to the present invention, that is, the dense first ceramic layer mainly containing alumina or chromia. The ceramics layer 3 including the fourth ceramics layer 4 and 8 and the second ceramics layer 5 which is an oxygen supply source can be directly formed on the metal substrate 1, as shown in FIG.

For example, as the metal substrate 1, CMSX-2,
When a single crystal base material such as CMSX-4 is used, if an MCrAlY alloy layer having a different composition is formed by coating and used for a long time in a high temperature atmosphere, the metal base material 1 is diffused due to element diffusion.
There is a possibility that the structure in the vicinity of the surface will recrystallize and the strength of the base material will decrease. In such a case, the ceramic layer 3 composed of the dense first ceramic layers 4 and 8 mainly composed of alumina or chromia and the second ceramic layer 5 serving as an oxygen supply source is directly provided on the metal substrate 1. It may be formed.

When used in a more severe high temperature environment, an Al-enriched layer 7 is further formed on the metal substrate 1 by the aluminum pack method or the like as shown in FIG. By forming the ceramic layer 3 on the first ceramic layer 7, the first ceramic layer 4 mainly made of alumina may be generated.

As shown in FIG. 5, when the ceramic layer 3 is formed directly on the metal base material 1, the first ceramic layers 4 and 8 are produced by the constituent elements of the metal base material 1. Further, as shown in FIG. 6, when the ceramics layer 3 is formed via the Al-enriched layer 7 provided on the metal substrate 1, the Al-enriched layer 7 is used to form the first ceramics mainly made of alumina. Layer 4 is produced. The specific conditions and manufacturing conditions of each layer are the same as the case of forming on the MCrAlY alloy layer 2, but when the first ceramic layers 4 and 8 mainly made of alumina or chromia and the metal base material 1 are in direct contact with each other. In particular, it is necessary to fully consider the relaxation of thermal stress by controlling the thickness of each layer.

Next, another embodiment of the heat-resistant member of the present invention will be described.

FIG. 7 is a sectional view showing an embodiment of another heat-resistant member of the present invention. In the figure, 11 is a metal base material, and as the metal base material 11, a heat-resistant alloy containing at least one selected from Ni, Co, and Fe as the main component is used as in the above-described embodiments.

An oxygen diffusion layer 12 is formed near the surface of the metal base material 11. Then, the MCrAlY alloy layer 13 is formed as a corrosion-resistant / oxidation-resistant metal coating via the oxygen diffusion layer 12, and the heat-resistant member 14 is constituted by these. The details of the MCrAlY alloy layer 13 are the same as those in the above-described embodiment.

The oxygen diffusion layer 12 described above can be formed, for example, by oxygen ion implantation or oxygen ion etching. The thickness of the oxygen diffusion layer 12 is not particularly limited, but it is preferably in the range of 100 nm to 10 μm. The reason is that if the thickness of the oxygen diffusion layer 12 exceeds 10 μm, the metal base material 11 is more likely to deteriorate.
This is because if it is less than 100 nm, the formation of the diffusion barrier layer (15) described in detail below may be uneven or insufficient. Furthermore, although the oxygen concentration in the oxygen diffusion layer 12 is not particularly limited, it is preferable that oxygen exists as solid solution oxygen in the metal substrate 11.

The ΜCrAlY alloy layer 2 typified by the ΝiCoCrAlY alloy or the like generally has a larger amount of Al and Cr added than the metal base material 1 from the viewpoint of improving the oxidation resistance. Therefore, the heat-resistant member 14 may be preheated,
Alternatively, when heat is applied during actual use, oxygen in the oxygen diffusion layer 12 reacts with Al or the like in the ΜCrAlY alloy layer 13 and, as shown in FIG.
At the interface with the AlY alloy layer 13, alumina, alumina and N
The oxide layer 15 is formed of a composite oxide or the like with an oxide such as i or Cr. These oxides have a small diffusion coefficient of the metal element in the substance and are effectively used as a diffusion barrier layer.

Therefore, even if the heat-resistant member having the diffusion barrier layer formed of the oxide layer 15 is used under the condition of being exposed to a high temperature environment for a long time, the metal base material 11 and the ΜCrAlY alloy layer 13 are It is possible to suppress element transfer between the two. As a result, the high temperature strength of the metal base material 11 can be prevented from lowering, and the heat resistant member 14 can be used stably for a long period of time.

Here, a major difference between the oxide layer 15 as the diffusion barrier layer and the diffusion barrier layer formed by the conventional CVD method is that the oxide layer 15 is different from the metal base material 11 and ΜCrAlY.
Since it is a substance generated by the interfacial reaction with the alloy layer 13, the adhesiveness to the metal base material 11 and the ΜCrAlY alloy layer 13 is good, which results in the oxide layer 15
The interfacial peeling due to the inclusion of as a diffusion barrier layer can be significantly suppressed. This is heat resistant member 1
4 greatly contributes to longer life.

In the heat-resistant member shown in FIG. 9, the surface oxide layer 16 is formed on the surface of the metal base material 11 in advance.
The rAlY alloy layer 13 is formed. The heat-resistant member 17 is composed of these. Surface oxide layer 16 described above
Is formed by pre-oxidizing the metal base material 11 in the air or in a reduced pressure atmosphere, and is made of Ni, Co, Cr, Al.
It is composed of an oxide such as the above or a composite oxide thereof, and exhibits excellent adhesion to the metal substrate 11. The surface oxide layer 16 functions as a diffusion barrier layer similarly to the oxide layer 15 of FIG.

When the surface oxide layer 16 is used as a diffusion barrier layer, for example, as shown in FIG.
First, Al diffusion treatment such as aluminum pack method is applied to the surface of Al to form an Al-enriched layer 18, a surface-oxidized layer 19 is formed in advance on the surface of the Al-enriched layer 18, The CrCrAlY alloy layer 13 may be formed. The surface oxide layer 19 is formed by pre-oxidizing the metal base material 11 on which the Al-enriched layer 18 is formed in the air or in a reduced pressure atmosphere. It is composed of a complex oxide of an oxide such as Co or Cr and an Al oxide.

Like the heat-resistant member 14 shown in FIGS. 7 and 8, the heat-resistant member 17 as described above has surface oxide layers 16 and 1.
Since 9 effectively functions as a diffusion barrier layer, it is possible to suppress element transfer between the metal base material 11 and the ΜCrAlY alloy layer 13 even when used under the condition of being exposed to a high temperature environment for a long time. it can. As a result, deterioration of the high temperature strength of the metal base material 11 can be prevented, and the heat resistant member 17
Can be used stably for a long period of time.

The heat-resistant member 1 of each of the above-mentioned embodiments.
4 and 17 are the ceramic layers 3 according to the above-described embodiment.
In addition to this, on the MCrAlY alloy layer 13, separately, silicon nitride, silicon carbide, alumina, zirconia, titanium nitride, aluminum nitride, SiAlON.
You may use, providing the heat shield layer which consists of ceramic materials, such as.

[0061]

Next, specific examples of the present invention will be described.

Example 1 On a Ni-base superalloy IN738LC, a thickness was prepared by a low vacuum spraying method.
After forming a NiCoCrAlY alloy layer of 150 μm,
EB-PVD method in 01Pa vacuum (substrate heating temperature: 1173K)
To form a Y-stabilized zirconia layer with various thicknesses. The average thickness of the Y-stabilized zirconia layers is about 30 each.
μm (Sample A), about 40 μm (Sample B), about 100 μm (Sample C), about 150 μm (Sample D), and about 200 μm (Sample E). Of these, samples A and B are examples of the present invention, and samples C to E correspond to comparative examples.

At this time, the cross section of each of the above-mentioned samples was
When observed by EDX, the average thickness of the samples A and B was about 1 μm at the interface between the NiCoCrAlY layer and the zirconia layer.
The oxide layer mainly composed of alumina was formed. In Samples C, D and E, the oxide layer mainly composed of alumina having an average thickness of about 4.0 to 5.5 μm was formed.

For each of the above samples, 1373K x 8 hours +
After repeating the heat treatment for 1000 cycles with 373 K × 1 hour as one cycle, the state of the ceramic layer was observed. As a result, Samples E, D, and C have 100 cycles and 300 cycles, respectively.
Some cracks were found in the ceramic layer after 500 cycles. Moreover, after 1000 cycles of repeated heat treatment tests, the peeling of the ceramic layer was remarkable, and
It was confirmed that the oxidation of the CrAlY layer progressed from the surface to the inside by 10 μm or more, and nickel oxide, cobalt oxide and other complex oxides were formed in addition to alumina.

On the other hand, samples A and B corresponding to the examples
No change in appearance was observed, and the ceramic layer was not damaged. Also, observing the cross-sectional structure,
The oxide layer was mainly composed of alumina, and the presence of the transition metal oxide or its composite oxide, which was observed in the exfoliated portions of Samples C, D, and E, was not seen.

Example 2 On a Ni-base superalloy IN738LC, the thickness was reduced by a low vacuum spraying method.
After forming a CoCrAlY alloy layer with a thickness of 150 μm and further performing an aluminum pack treatment to form an Al-enriched layer with an average thickness of 20 μm, 8 wt% Y ₂ with an average thickness of 30 μm was formed by atmospheric spraying.
O ₃ was formed -ZrO ₂ sprayed layer. After this, 5 × 10 ^-3 Pa
For 2 hours at 1503K in a vacuum oven, subjected to a preliminary heat treatment of 16 hours at 1143K Subsequently, Al-enriched layer and 8 wt% Y ₂ O ₃
Sample A was prepared by forming an oxide layer mainly composed of alumina and having an average thickness of about 2 μm at the interface with the —ZrO ₂ sprayed layer.

On the other hand, 2 at 1503K in a vacuum furnace of 5 × 10 ⁻³ Pa
Heat treated Ni at 1143K for 16 hours
The thickness of the base superalloy IN738LC is 150 by low vacuum spraying.
After forming a CoCrAlY alloy layer having a thickness of μm and further performing an aluminum pack treatment to form an Al-enriched layer having an average thickness of 20 μm, 8 wt% Y ₂ O ₃ having an average thickness of 30 μm was formed by atmospheric spraying.
It was used as a sample B to form -ZrO ₂ sprayed layer. This sample B
In, the oxide layer like Sample A was not formed at the interface between the Al-enriched layer and the ZrO ₂ sprayed layer, which corresponds to a comparative example with the present invention.

Each sample described above was subjected to a repeated heat treatment test with 1273K × 0.5 hours + 373K × 0.5 hours as one cycle to examine the durability of each coating. As a result, sample B
In 2000 cycles, the ZrO ₂ sprayed layer at the end portion peeled off and cracks were generated in the entire coating. Further observation of the structure of the cross section revealed that the oxide layer formed at the interface with the ZrO ₂ sprayed layer zirconia had a thickness of 10 μm or more, and the exfoliation also occurred inside the alumina layer on the surface of the Al-enriched layer. Further, oxides of transition metals such as Ni and Co and complex oxides thereof are also observed in most of the unpeeled portions, and some oxides and CoCrAlY
There was also a part where peeling was progressing at the interface with the alloy layer.

On the other hand, in the sample A corresponding to the example, there was no change in appearance even after the repeated heat treatment test of 2000 cycles or more, and no peeling of the ceramic layer was observed.
Also, when the inside was examined in detail, the thickness of the oxide layer composed mainly of alumina was 3 μm, and there were peeled parts, Ni and C.
No transition metals such as o or transition metal oxides were observed, and CoC
The oxidation resistant coating function of the rAlY alloy layer was maintained.

Example 3 A round bar (diameter: 10 mm) made of Ni-base super heat-resistant alloy CΜ-247
X 20mm) surface, thickness of about 1 by low pressure plasma spraying method
After forming a NiCoCrAlY alloy layer of 50 μm, an atmospheric plasma spraying method was used to deposit 8 wt% Y ₂ O with an average thickness of 50 μm.
_{A 3} stabilized ZrO ₂ layer was formed. After that, a preheat treatment was performed at 1503 K for 2 hours and subsequently at 1143 K for 16 hours in a vacuum furnace of 5 × 10 ⁻³ Pa to obtain a sample A. NiC after heat treatment
oCrAlY alloy layer and 8 wt% Y ₂ O ₃ stabilized ZrO ₂
At the interface with the layer, a layer composed of alumina and a composite oxide of Al and Y having an average thickness of about 1.3 μm was formed. On the other hand, as a comparative example with the present invention, the thickness of a round bar made of Ni-base super heat-resistant alloy CΜ-247, which was previously heat-treated at 1503K for 2 hours and subsequently at 1143K for 16 hours, was formed by a reduced pressure plasma spraying method. After forming a NiCoCrAlY alloy layer of about 150 μm, an average thickness of 50 is obtained by atmospheric plasma spraying.
Sample B was prepared by forming an 8 wt% Y ₂ O ₃ -stabilized ZrO ₂ layer of μm.

Each of the above samples was subjected to 250 m in the atmosphere at 1123 K, which simulated the atmosphere to which the members were exposed during gas turbine operation.
A stress of MPa was applied and a repeated heat treatment test was performed at room temperature for 12 hours. As a result, in Sample A, peeling did not occur even after 100 times. After the test, the cross section of the sample was observed, and it was confirmed that the NiCoCrAlY alloy layer and the 8 wt% Y ₂
At the interface with the O ₃ -stabilized ZrO ₂ layer, a layer having a thickness of about 1.5 μm and mainly made of alumina was present, and an oxide layer containing Ni or Co was not detected.

On the other hand, in the case of the sample B which was not subjected to the preliminary heat treatment after forming the film, the number of times was more than 60 times.
% Y ₂ O ₃ stabilized ZrO ₂ layer was peeled off as one body. This sample was continuously tested up to 100 cycles, and the cross section of the part without peeling was observed.
An oxide layer of m has formed, and N is contained in this oxide layer.
It was observed that a complex oxide of i, Co, and Al was formed in layers.

Example 4 On the surface of a round bar made of Ni-base super heat resistant alloy CMSX-2,
About 140 μm thick NiCoC by low pressure plasma spraying
After forming the rAlY alloy layer, an 8 wt% Y ₂ O ₃ stabilized ZrO ₂ layer having an average thickness of 20 μm was formed by an atmospheric plasma spraying method. After this, in a vacuum furnace of 8 × 10 ^-3 Pa at 1588K
Sample A was preheated at 1323K for 16 hours and 1123K for 48 hours for 3 hours. NiCo after heat treatment
At the interface between the CrAlY alloy layer and the 8 wt% Y ₂ O ₃ -stabilized ZrO ₂ layer, about 3 μm thick alumina and Al and Y
A layer composed of a composite oxide of was formed.

On the other hand, as a comparative example with the present invention,
The surface of a round bar made of Ni-based super heat-resistant alloy CMSX-2, which was heat-treated at 8K for 3 hours, then at 1323K for 16 hours, and at 1123K for 48 hours, had a thickness of about 1
After forming a NiCoCrAlY alloy layer of 40 μm, an average thickness of 20 μm of 8 wt% Y ₂ O was formed by an atmospheric plasma spraying method.
_{A 3-} stabilized ZrO ₂ layer was formed to obtain Sample B.

Each of the above samples was subjected to 250 m in the atmosphere at 1123K which simulated the atmosphere to which the members were exposed during gas turbine operation.
A stress of MPa was applied and a repeated heat treatment test was performed at room temperature for 12 hours. As a result, in Sample A, peeling did not occur even after 100 cycles. After the test, the cross section of the sample was observed and found to contain 8% by weight of the NiCoCrAlY alloy layer.
At the interface with the Y ₂ O ₃ stabilized ZrO ₂ layer, the thickness is about 4 μm.
Has an oxide layer mainly composed of alumina.
No oxide layer containing Co or Co was detected.

On the other hand, in the sample B which was not subjected to the preliminary heat treatment after the film formation, the oxide layer on the surface of the NiCoCrAlY alloy layer and the oxide layer on the surface of the NiCoCrAlY alloy layer partly exceeded the weight of 50 times.
% Y ₂ O ₃ stabilized ZrO ₂ layer was peeled off as one body. This sample was continuously tested up to 100 cycles, and the cross section of the part that did not peel off was observed.
Oxide layer has been formed, and N is contained in this oxide layer.
It was observed that a complex oxide of i, Co, and Al was formed in layers.

Example 5 On the surface of a round bar made of Ni-base super heat-resistant alloy IN-738,
NiCoC of about 150 μm thickness by low pressure plasma spraying
After forming the rAlY alloy layer, an 8 wt% Y ₂ O ₃ stabilized ZrO ₂ layer having an average thickness of 10 μm was formed by atmospheric plasma spraying. After this, at 1393K in a 2 × 10 ^-2 Pa vacuum furnace.
Sample A was preheated for 2 hours and then at 1123K for 24 hours. At the interface between the NiCoCrAlY alloy layer after heat treatment and the 8 wt% Y ₂ O ₃ -stabilized ZrO ₂ layer, an oxide layer with an average thickness of about 1 μm is formed, and this oxide layer mainly consists of alumina. However, formation of a composite oxide of Al and Y was also partially observed.

On the other hand, as a comparative example with the present invention, 1393K was previously prepared.
The surface of a round bar made of Ni-based super heat-resistant alloy CMSX-2, which had been preheated for 2 hours at 1123K for 24 hours, was applied to the surface of NiC with a thickness of about 150 μm by low pressure plasma spraying.
After forming the oCrAlY alloy layer, 8 wt% Y ₂ O ₃ stabilized ZrO with an average thickness of 10 μm was formed by atmospheric plasma spraying.
_Two layers were formed to obtain Sample B.

Each sample described above was simulated in an atmosphere at 1123 K in which the members were exposed during gas turbine operation.
A stress of MPa was applied and a repeated heat treatment test was performed at room temperature for 12 hours. As a result, in Sample A, peeling did not occur even after 100 cycles. After the test, the cross section of the sample was observed and found to contain 8% by weight of the NiCoCrAlY alloy layer.
At the interface with the Y ₂ O ₃ stabilized ZrO ₂ layer, the thickness is about 2 μm.
Has an oxide layer mainly composed of alumina.
No oxide layer containing Co or Co was detected.

On the other hand, in the sample B which was not subjected to the preliminary heat treatment after the film formation, the oxide layer on the surface of the NiCoCrAlY alloy layer and the weight of 8 wt
% Y ₂ O ₃ stabilized ZrO ₂ layer was peeled off as one body. This sample was continuously tested up to 100 cycles, and the cross section of the part that did not peel off was observed.
A μm oxide layer has been formed, and N is contained in this oxide layer.
It was observed that a complex oxide of i, Co, and Al was formed in layers.

Example 6 On the surface of a round bar made of Ni-base super heat resistant alloy CMSX-2,
About 140 μm thick NiCoC by low pressure plasma spraying
After forming the rAlY alloy layer, an 8 wt% Y ₂ O ₃ stabilized ZrO ₂ layer having an average thickness of 20 μm was formed by an atmospheric plasma spraying method. After this, in a vacuum furnace of 8 × 10 ^-3 Pa at 1588K
Sample A was preheated at 1323K for 16 hours and 1123K for 48 hours for 3 hours. NiCo after heat treatment
At the interface between the CrAlY alloy layer and the 8 wt% Y ₂ O ₃ -stabilized ZrO ₂ layer, a layer having a thickness of about 3 μm alumina and a composite oxide of Al and Y was formed.

On the other hand, as a comparative example with the present invention, a NiCoCrAlY layer having a thickness of about 140 μm was formed on the surface of a round bar made of Ni-base super heat-resistant alloy CMSX-2 by a low pressure plasma spraying method.
Form an alloy layer, which is 1588K for 3 hours, followed by 1
After heat treatment at 323K for 16 hours and 1123K for 48 hours, 8 wt% Y _{2 with} an average thickness of 20μm was formed by atmospheric plasma spraying.
An O ₃ -stabilized ZrO ₂ layer was formed to obtain Sample B.

Each of the above-mentioned samples was subjected to 250 m in the atmosphere at 1123K which simulated the atmosphere to which the members were exposed during gas turbine operation.
A stress of MPa was applied and a repeated heat treatment test was performed at room temperature for 12 hours. As a result, in Sample A, peeling did not occur even after 100 cycles. After the test, observing the cross section of the sample, it was found that the NiCoCrAlY alloy layer and
At the interface with the% Y ₂ O ₃ stabilized ZrO ₂ layer, a thickness of about 3.5
There is an oxide layer consisting mainly of μm alumina,
No oxide layer containing Ni or Co was detected.

On the other hand, in the sample B which was not subjected to the preliminary heat treatment after the film formation, the Ni content was partially exceeded from the point of exceeding 50 times.
Oxide layer on the surface of CoCrAlY alloy layer and 8 wt% Y ₂ O
_{3 The} stabilized ZrO ₂ layer was peeled off as a unit. This sample was continuously tested up to 100 cycles, and the cross section of the non-exfoliated part was observed. As a result, an oxide layer with a thickness of about 7 μm was formed.
It was observed that composite oxides of o and Al were formed in layers.

Example 7 On the surface of a round bar made of Ni-base super heat resistant alloy CMSX-2,
NiCoC of about 100 μm thickness by low pressure plasma spraying
After forming the rAlY alloy layer, an 8 wt% Y ₂ O ₃ stabilized ZrO ₂ layer having an average thickness of 30 μm was formed by an atmospheric plasma spraying method, and a silicon nitride layer having an average thickness of 20 μm was further formed. Then, a pre-heat treatment was performed in a vacuum furnace of 8 × 10 ⁻³ Pa at 1588K for 3 hours, subsequently at 1323K for 16 hours, and at 1123K for 48 hours to obtain Sample A. NiCoCr after heat treatment
At the interface between the AlY alloy layer and the 8 wt% Y ₂ O ₃ -stabilized ZrO ₂ layer, a layer mainly composed of alumina having a thickness of about 2.7 μm was formed.

On the other hand, as a comparative example with the present invention, a NiCoCrAlY film having a thickness of about 100 μm was formed on the surface of a round bar made of Ni-base super heat-resistant alloy CMSX-2 by a low pressure plasma spraying method.
Form an alloy layer, which is 1588K for 3 hours, followed by 1
After heat treatment at 323K for 16 hours and 1123K for 48 hours, 8 wt% Y _{2 with} an average thickness of 20μm was formed by atmospheric plasma spraying.
Sample B was prepared by sequentially forming an O ₃ stabilized ZrO ₂ layer and a silicon nitride layer having an average thickness of 20 μm.

Each of the above-mentioned samples was subjected to 250 m in the atmosphere at 1123K which simulated the atmosphere to which the members were exposed during gas turbine operation.
A stress of MPa was applied and a repeated heat treatment test was performed at room temperature for 12 hours. As a result, in Sample A, peeling did not occur even after 100 cycles. After the test, observing the cross section of the sample, it was found that the NiCoCrAlY alloy layer and
At the interface with the% Y ₂ O ₃ stabilized ZrO ₂ layer, a thickness of about 2.8
There is an oxide layer consisting mainly of μm alumina,
No oxide layer containing i or Co was detected.

On the other hand, in the sample B which was not subjected to the preliminary heat treatment after the film formation, the Ni content was partially exceeded from 55 times.
Oxide layer on the surface of CoCrAlY alloy layer and 8 wt% Y ₂ O
_{3 The} stabilized ZrO ₂ layer was peeled off as a unit. This sample was continuously tested up to 100 cycles, and the cross section of the part that had not been peeled off was observed. As a result, an oxide layer with a thickness of approximately 6.5 μm was formed. Ni and C were formed in this oxide layer.
It was observed that composite oxides of o and Al were formed in layers.

Example 8 Ni-base super heat-resistant alloy IN-939 which has been subjected to a tempering treatment in advance.
A CoNiCrAlY alloy layer with a thickness of approximately 150 μm was formed on the surface of a round bar consisting of, by a low pressure plasma spraying method, and then with an atmospheric plasma spraying method, an average thickness of 50 μm was 8% by weight.
A Y ₂ O ₃ stabilized ZrO ₂ layer was formed. After this, 5 × 10
Sample A was preheated at 1023K for 5 hours in a vacuum furnace of ^-1 Pa. CoNiCrAlY alloy layer after heat treatment
At the interface with the 8 wt% Y ₂ O ₃ -stabilized ZrO ₂ layer, a layer having a thickness of about 2 μm and mainly composed of alumina and chromia was formed.

On the other hand, as a comparative example with the present invention, a thickness of about 150 μm was formed on the surface of a round bar made of a Ni-base superheat-resistant alloy IN-939 which had been subjected to tempering treatment by a low pressure plasma spraying method.
A CoNiCrAlY alloy layer of m 2 was formed to obtain Sample B.

Each of the above samples was subjected to 250 m in the atmosphere at 1023 K simulating the atmosphere to which the members are exposed during gas turbine operation.
A stress of MPa was applied and a repeated heat treatment test was performed at room temperature for 12 hours. As a result, in Sample A, peeling did not occur even after 100 cycles. After the test, the cross section of the sample was observed, and it was found that the weight of the CoNiCrAlY alloy layer was 8%.
At the interface with the% Y ₂ O ₃ stabilized ZrO ₂ layer, a thickness of about 3.5
There was an oxide layer of μm mainly consisting of alumina and chromia.

On the other hand, in the sample B, the oxide layer on the surface of the CoNiCrAlY alloy layer was partially peeled off after the number of times exceeded 50 times. This sample was continuously tested up to 100 cycles and the cross section of the part which was not peeled off was observed. As a result, a rough oxide layer consisting of Ni, Co, Cr and Al having a thickness of about 10 μm was formed. The consumption was greater than that of sample A.

Example 9 An aluminum pack treatment was performed on a Ni-base superalloy CMSX-2 to form an Al-rich layer having an average thickness of 5 μm, and then an EB-PVD method (substrate heating temperature: 1173K, Vacuum degree: 0.00
Sample A was prepared by forming an 8 wt% Y ₂ O ₃ —ZrO ₂ sprayed layer having an average thickness of 50 μm at 1 Pa). On the other hand, A similarly formed
l 8% by weight with an average thickness of 100 μm on the enriched layer under the same conditions
Sample B (Comparative Example) with Y ₂ O ₃ —ZrO ₂ sprayed layer formed
And Each of these samples was subjected to 1373K in a vacuum of 1.0 × 10 ^-3 Pa.
Then, a heat treatment was performed for 2 hours to form an oxide layer mainly composed of alumina and having an average thickness of about 2 μm (Sample A) and about 4.5 μm (Sample B) at the interface between the Al-enriched layer and the ZrO ₂ sprayed layer.

Each sample described above was subjected to a repeated heat treatment test in which 1273K × 0.5 hours + 373K × 0.5 hours was set as one cycle to examine the durability of each coating. As a result, sample B
Then, peeling occurred at the end of the ZrO ₂ sprayed layer after 100 cycles. After continuing the test for 800 more cycles,
Most of the ZrO ₂ sprayed layer was peeled off, and the oxidation of the Al-enriched layer proceeded to the inside of the depth of 8 μm or more, and the Al-enriched layer was significantly damaged. Besides oxides, oxides of transition metals (nickel oxides) and their composite oxides (composite oxides of NiAl) were also found as oxides.

On the other hand, in Sample A, there was no change in appearance even after the repeated heat treatment test for 800 cycles or more, and no peeling of the ceramic layer was observed. Also,
When the inside was examined in detail, the alumina layer had grown to a thickness of about 3.3 μm, but no peeled portion was observed,
The oxidation resistant coating function of the CoCrAlY layer was maintained. Example 10 On the surface of a round bar made of Ni-based super heat-resistant alloy C-247,
Oxygen ions are implanted with an ion implanter to a thickness of approximately 100
An oxygen diffusion layer of nm was formed. After that, the thickness of the Ni-base superalloy is reduced by the EB-PVD method through the oxygen diffusion layer.
A 150 μm NiCoCrAlY alloy layer was formed.

The heat-resistant member thus obtained was subjected to heat treatment in an Ar atmosphere furnace at 1373K for 2 hours and subsequently at 1123K for 16 hours. Ni-base superalloy and NiC after heat treatment
An alumina layer having a thickness of about 100 nm was formed at the interface with the oCrAlY alloy layer. This sample, 1173K in air
When a creep test was carried out under a stress of 250 MPa at
No fracture was observed even after holding for a time.

As a comparative example with the present invention, a NiCoCrAlY layer having a thickness of about 150 μm was directly formed on the surface of a round bar made of Ni-base superheat-resistant alloy C-247 by the EB-PVD method. After heat-treating this sample under the same conditions as in the above-mentioned example, a creep test was conducted under the same conditions, whereupon it broke after 80 hours had elapsed.

When this sample was cut and its cross-section was observed, a region where the precipitation of the strengthening phase (γ ′ phase) was disturbed was observed in the substrate in the vicinity of the interface by about 20 μm, and it was composed of Cr and W. A fragile morphogenetic phase was observed. On the other hand, in the samples according to the above-described examples, such a region and the generated phase were not observed.

Example 11 The surface of a round bar made of a Ni-base super heat-resistant alloy CMSΧ-2 was
Oxygen ion etching was performed in a reduced pressure oxygen atmosphere of 0.5Pa using a magnetron sputtering device, and the thickness near the surface was approximately 1
An oxygen diffusion layer of 00 nm was formed. After that, a NiCoCrA layer having a thickness of about 150 μm is continuously formed on the surface on which the oxygen diffusion layer is formed.
An IY alloy layer was formed.

The heat-resistant member thus obtained was subjected to heat treatment in an Ar atmosphere furnace at 1323K for 16 hours and subsequently at 1123K for 48 hours. Ni-base superalloy and NiC after heat treatment
An alumina layer having a thickness of about 100 nm was formed at the interface with the oCrAlY alloy layer. This sample in the atmosphere at 1173K
When a creep test was carried out under a stress of 250 MPa at
No fracture was observed even after holding for a time.

As a comparative example with the present invention, a NiCoCrAlY layer having a thickness of about 150 μm was directly formed on the surface of a round bar made of Ni-base super heat-resistant alloy CMSX-2 by an EB-PVD apparatus. After heat-treating this sample under the same conditions as in the above example, a creep test was carried out under the same conditions, and it broke at the time when 90 hours had elapsed.

When this sample was cut and the cross-section was observed, a region where the precipitation of the strengthening phase (γ 'phase) was disturbed was observed in the base material in the vicinity of the interface by about 20 μm, and it was composed of Cr and W. A fragile morphogenetic phase was observed. On the other hand, in the samples according to the above-mentioned examples, such a region and a generated phase were not observed.

Example 12 The surface of a round bar made of Ni-based super heat-resistant alloy CMSΧ-2 was
At a temperature of 1273K in a chamber where the atmospheric pressure is reduced to 0.5Pa.
Oxidation treatment was performed for 5 hours to form a composite oxide layer of Al and Ni. Then, a CoNiCrAlY alloy layer having a thickness of about 100 μm was formed on the surface on which the complex oxide layer was formed by the low pressure plasma spraying method.

The heat-resistant member thus obtained was placed in the atmosphere
Heat treatment was performed at 1123K for 1000 hours. When a creep test was performed on the sample after the heat treatment under a stress of 250 MPa at 1173 K in the air, no rupture was observed even after holding for 100 hours.

As a comparative example with the present invention, a CB-PVD EB-PVD alloy layer having a thickness of about 150 μm was directly formed on the surface of a round bar made of Ni-base super heat-resistant alloy CMSX-2.
Formed by the device. After heat-treating this sample under the same conditions as in the above-mentioned example, a creep test was conducted under the same conditions. As a result, the sample fractured after 70 hours.

When this sample was cut and the cross-section was observed, a region where the precipitation of the strengthening phase (γ 'phase) was disturbed was observed in the base material in the vicinity of the interface by about 30 μm, and it was composed of Cr and W. A fragile morphogenetic phase was observed. On the other hand, in the samples according to the above-described examples, such a region and the generated phase were not observed.

Example 13 The surface of a round bar made of Ni-base super heat-resistant alloy CMSX-2 was
At a temperature of 1273K in a chamber where the atmospheric pressure is reduced to 0.5Pa.
Oxidation treatment was performed for 5 hours to form a composite oxide layer of Al and Ni. Then, a CoNiCrAlY alloy layer having a thickness of about 100 μm was formed on the surface on which the complex oxide layer was formed by a low pressure plasma spraying method.

[0108] The heat-resistant member thus obtained was placed in the atmosphere
Heat treatment was performed at 1123K for 1000 hours. A creep test was performed on the heat-treated sample at 1173 K under a stress of 250 MPa in the air, and no fracture was observed even after holding for 100 hours.

As a comparative example of the present invention, a CoNiCrAlY alloy layer having a thickness of about 150 μm was directly formed on the surface of a round bar made of Ni-base super heat-resistant alloy CMSX-2 by EB-PVD.
Formed by the device. After heat-treating this sample under the same conditions as in the above-mentioned example, a creep test was conducted under the same conditions. As a result, the sample fractured after 70 hours.

When this sample was cut and the cross-section was observed, a region where the precipitation of the strengthening phase (γ 'phase) was disturbed was observed in the base material in the vicinity of the interface by about 30 μm, and it was composed of Cr and W. A fragile morphogenetic phase was observed. On the other hand, in the samples according to the above-described examples, such a region and the generated phase were not observed.

Example 14 On the surface of a round bar made of Ni-base super heat-resistant alloy CMSX-2,
After forming an Al-enriched layer by the aluminum pack method, in the atmosphere
Oxidation treatment was performed at 1273K for 30 minutes to form an Al oxide layer. After this oxidation treatment, a CoNiCrAl layer with a thickness of about 100 μm was formed on the surface on which the oxide layer was formed by low pressure plasma spraying.
The Y layer was formed.

The heat-resistant member thus obtained was heat-treated for 1000 hours in the atmosphere of 1123K. A creep test was performed on the heat-treated sample at 1173 K under a stress of 250 MPa in the air, and no fracture was observed even after holding for 100 hours.

As a comparative example with the present invention, a CoNiCrAlY alloy layer having a thickness of about 150 μm was directly formed on the surface of a round bar made of Ni-base super heat-resistant alloy CMSX-2 by EB-PVD.
Formed by the device. After heat-treating this sample under the same conditions as in the above-mentioned example, a creep test was conducted under the same conditions. As a result, the sample fractured after 70 hours.

When this sample was cut and the cross-section was observed, a region where the precipitation of the strengthening phase (γ ′ phase) was disturbed was observed in the base material near the interface by about 30 μm, and it was composed of Cr and W. A fragile morphogenetic phase was observed. On the other hand, in the samples according to the above-described examples, such a region and the generated phase were not observed.

Example 15 On the surface of a round bar made of Ni-based super heat-resistant alloy CMSΧ-2,
Oxygen ions are implanted with an ion implanter to a thickness of about 50 nm
The oxygen diffusion layer of was formed. After that, a NiCoCr layer having a thickness of about 100 μm was formed on the surface of the oxygen diffusion layer by low pressure plasma spraying.
An AlY layer was formed.

The heat-resistant member thus obtained was subjected to heat treatment in an Ar atmosphere furnace at 1323K for 16 hours and subsequently at 1123K for 48 hours. Ni-base superalloy and NiC after heat treatment
An alumina layer having a thickness of about 50 nm was formed at the interface with the oCrAlY alloy layer. Next, after heat treatment, NiCoCrAl
8% by weight on the Y alloy layer by the atmospheric plasma spraying method
A Y ₂ O ₃ partially stabilized ZrO ₂ layer having a thickness of 200 μm was formed.
When this sample was subjected to a creep test at 1173 K under a stress of 250 MPa in the atmosphere, no rupture was observed even after holding for 100 hours.

As a comparative example with the present invention, a NiCoCrAlY alloy layer having a thickness of about 100 μm was directly formed on the surface of a round bar made of Ni-base super heat-resistant alloy CMSX-2 by a low pressure plasma spraying method, and an Ar atmosphere furnace was used. Heat treatment was carried out at 1323K for 16 hours and subsequently at 1123K for 48 hours. 8 wt% Y ₂ O ₃ partially stabilized ZrO ₂ was further formed on the NiCoCrAlY alloy layer after heat treatment by the atmospheric plasma spraying method.
The layer was formed to 200 μm. When the creep test of this sample was performed under the same conditions as those of the examples, the sample fractured after 70 hours.

When this sample was cut and the cross-section was observed, a region where the precipitation of the strengthening phase (γ 'phase) was disturbed was observed in the base material in the vicinity of the interface by about 30 μm, and it was composed of Cr and W. A fragile morphogenetic phase was observed. On the other hand, in the samples according to the above-described examples, such a region and the generated phase were not observed.

[0119]

As described above, according to the heat-resistant member of the present invention, deterioration due to oxidation or corrosion of the metal base material can be effectively suppressed even when used for a long time in a high temperature atmosphere. It is possible to significantly improve the reliability and life of the heat resistant member.

[Brief description of drawings]

FIG. 1 is a cross-sectional view schematically illustrating a structure of an embodiment of a first heat-resistant member of the present invention.

FIG. 2 is a cross-sectional view showing a modified example of the heat resistant member shown in FIG.

FIG. 3 is a cross-sectional view schematically showing the structure of another embodiment of the first heat resistant member of the present invention.

FIG. 4 is a cross-sectional view showing an example of a manufacturing process of the heat-resistant member shown in FIGS. 1 and 3.

FIG. 5 is a sectional view schematically showing a structure of an embodiment of a second heat resistant member of the present invention.

FIG. 6 is a cross-sectional view schematically showing the structure of another embodiment of the second heat resistant member of the present invention.

FIG. 7 is a sectional view schematically showing the structure of another embodiment of the heat-resistant member of the present invention.

8 is a cross-sectional view schematically showing a state after the heat-resistant member shown in FIG. 7 has been subjected to preliminary heat treatment or the like.

FIG. 9 is a cross-sectional view schematically showing the structure of another embodiment of the heat resistant member of the present invention.

FIG. 10 is a sectional view schematically showing the structure of still another embodiment of the heat-resistant member of the present invention.

[Explanation of symbols]

 1, 11 ... Metal substrate 2, 13 ... MCrAlY alloy layer 3 ... Ceramics layer 4, 8 ... First ceramics layer 5 ... Second ceramics layer 6, 9, 10, 14, 17 ... Heat-resistant member 7 ... Al-enriched layer 12 ... Oxygen diffusion layer 15 ... Diffusion barrier layer 16, 19 ... Surface oxide layer

Continuation of front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical indication C23C 14/58 C23C 14/58 A 28/00 28/00 A (72) Inventor Hiroki Inagaki City, Kawasaki, Kanagawa Komukai-Toshiba-cho No. 1 Inside Toshiba Corporation R & D Center (72) Inventor Masako Nakahashi No. 1 Komukai-Toshiba Town, Kawasaki City, Kanagawa Prefecture

Claims (5)

[Claims] 1. A metal base material made of an alloy containing at least one selected from Ni, Co and Fe, and an MCrAlY alloy layer formed by coating on the metal base material (provided that M
Represents at least one element selected from Ni, Co and Fe) and a ceramic layer having an average thickness of 1 to 50 μm provided on the MCrAlY alloy layer, and the ceramic layer is the MCrAlY alloy layer. A first ceramics layer formed mainly of alumina, and a second ceramics layer formed on the first ceramics layer and made of oxide-based ceramics having oxygen dissociation ability (excluding alumina) formed on the first ceramics layer. A heat resistant member having: 2. The heat resistant member according to claim 1, wherein the first ceramic layer contains a composite oxide of Al and Y. 3. A metal base material made of an alloy containing at least one selected from Ni, Co and Fe, and a ceramic layer formed on the metal base material directly or through an Al-rich layer. The ceramic layer is a first ceramic layer mainly composed of at least one selected from alumina and chromia formed on the metal base material or the Al-enriched layer, and oxygen existing on the first ceramic layer. A heat-resistant member, comprising: a second ceramic layer made of oxide-based ceramics (excluding alumina and chromia) having dissociation ability. 4. A metal base material made of an alloy containing at least one selected from Ni, Co and Fe, and an oxygen diffusion layer or a surface oxidation layer provided on the surface part of the metal base material.
Alternatively, a surface oxide layer provided on an Al-enriched layer formed on the metal substrate, and MCrAlY coated on the metal substrate or the Al-enriched layer via the oxygen diffusion layer or the surface oxide layer. A heat-resistant member, comprising an alloy layer (wherein M represents at least one element selected from Ni, Co, and Fe). 5. MC on the surface of a metal substrate made of an alloy containing at least one selected from Ni, Co and Fe.
a step of forming an rAlY alloy layer (where M represents at least one element selected from Ni, Co and Fe), and an oxide system having an oxygen dissociation ability by using a thermal spraying method on the surface of the MCrAlY alloy layer. A step of forming a ceramics layer (excluding alumina), and a metal base material on which the oxide-based ceramics layer is formed,
And a heat treatment under a temperature condition of 1373 K or higher in a low oxygen atmosphere.