JPH0320451A - Ceramics-applied turbine rotor blade - Google Patents

Abstract

PURPOSE:To produce the turbine rotor blade excellent in high temp. corrosion resistance by forming a coating layer consisting of ceramic layer, mixture layer, and alloy layer on the front edge part of a rotor blade base material consisting of a heat resisting alloy composed essentially of Ni, etc., under specific conditions. CONSTITUTION:A coating layer in which a layer 13 of an alloy composed principally of Co and/or Ni, incorporating Cr, Al, Hf, etc., and superior in high temp. oxidation resistance and high temp. corrosion resistance to a base material 12, the layer 14 of a mixture consisting of the above-mentioned alloy and ZrO2- type ceramics and a ceramic layer 11 consisting of ZrO2-type ceramics are successively laminated is formed on the rotor blade base material 12 of a gas turbine rotor blade consisting of a heat resisting alloy composed principally of at least one element among Ni, Co, and Fe. Further, it is preferable that the thicknesses of the ceramic layer 11, the alloy layer 13 and the mixture layer 14 are regulated to 0.05-1.0mm, 0.03-0.5mm, and 0.03-0.5mm, respectively. By this method, the turbine rotor blade sufficiently showing a thermal stress relaxation function under high temp. oxidation and high temp. corrosion conditions can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a rotor blade for a gas turbine used in a high temperature or high temperature corrosive environment. [Prior Art] Technology for increasing the temperature of gas turbines is being studied with the aim of improving the power generation efficiency of gas turbine plants for power generation. Furthermore, in order to improve the efficiency of coal gasification gas turbines, it is essential to establish high temperature technology. As gas turbine plants move toward higher temperatures, improvements in the heat resistance of components are desired. The main method for this is the development of materials constituting the members, and the temperature of metal materials, even Ni or Go-based superalloys, is about 850°C. On the other hand, although ceramics have a sufficiently high temperature resistance, they have problems such as toughness, especially in rotor blades, which are high-speed rotating bodies. Therefore, as another method of increasing the temperature, there is a method of preventing the member from becoming high temperature. This method combines cooling of the component with a ceramic coating with low thermal conductivity. Such coatings are called thermal barrier coatings (
Ding hermal barrier coating;
(hereinafter abbreviated as TBC). Figures 11 and 12 show a perspective view and a straight sectional view of a gas turbine rotor blade.
In the cross-sectional view of FIG. 12, 1 indicates the anterior edge, 2 indicates the dorsal surface, 3 indicates the dorsal posterior surface, 4 indicates the ventral surface, and 5 indicates the ventral posterior edge. FIG. 13 shows the heat transfer coefficient from the combustion gas to the rotor blades at each of these parts. This result shows that the heat transfer coefficient near the leading edge of the blade is large, that is, the heat input to the blade is large. A large heat input means a high blade temperature. FIG. 14 shows a known TBC construction wing. In this case, the TBC is provided in the portion of the rotor blade exposed to combustion gas, the shaded portion in FIG. Furthermore, in such a known TBC constructed wing, the T
BC has a structure as shown in FIG. 4, with a ceramic layer provided through an alloy layer. TBC is a combination of a heat-resistant alloy that makes up the base material and a ceramic coating layer with different physical properties. An important technical issue for TBC is the relaxation of thermal stress caused by the difference in physical properties between the base material and the ceramic N layer. In particular, in gas turbines and the like, damage such as peeling occurs to the ceramic coating layer due to thermal stress caused by thermal cycles such as starting and stopping. In order to alleviate such thermal stress, it is known to provide an intermediate layer between the ceramic coating layer and the base material made of a heat-resistant alloy to alleviate the difference in thermal expansion coefficient (for example, Japanese Patent Laid-Open No. 62-211362 (see publication). The intermediate layer is generally a mixture of ceramic and metal.

The coefficient of thermal expansion of such a mixture coating layer varies depending on the mixing ratio, but it is generally considered to have a value intermediate between the respective coefficients of thermal expansion of the ceramic and metal constituting the mixture coating layer. When this type of intermediate layer is provided between the ceramic layer and the base material, it can naturally be expected to have an effect of alleviating thermal stress.

On the other hand, the ceramic coating layer used in TBC is mainly produced by thermal spraying and is a porous body. This porous ceramic coating layer can relieve thermal stress by itself due to its porous structure.

However, since TBC is used under high temperature and corrosive conditions,
High-temperature oxidation or high-temperature corrosion occurs in the intermediate layer below the ceramic coating layer through the porous ceramic coating layer. Therefore, the present inventors conducted an oxidation test on a coating layer made of a mixture of ceramic and metal. For the test piece, a mixture coating layer was created on the surface of the base material, then the base material was removed and a sample made of the mixture was taken out. after that. 1000℃, 10
An oxidation test was carried out by heating in the air for 00 hours. As a result, in the oxidation test, significant internal oxidation progressed in the sample consisting of the mixture. The reason for this is that the coating layer, which is a mixture of ceramic powder and metal powder, is simply a layered layer of these two types of powder by thermal spraying, and there are defects at the boundary between them, so internal oxidation occurs through these defects. It is thought that this will progress. Such internal oxidation of the intermediate layer progressed significantly even in the test specimens that were coated with a ceramic coating consisting of a ceramic coating layer, an intermediate layer consisting of a mixture, and a base material. In addition, such ceramic coatings undergo high-temperature oxidation tests (1000°C, 1000°C).
After h), the ceramic layer was peeled off. in this way,
The intermediate layer, which is created by the mixture originally intended to alleviate thermal stress, does not fulfill its original purpose. The reason for this is that the intermediate layer generates new thermal stress due to internal oxidation of the intermediate layer itself, and furthermore, the intermediate layer at the boundary between the ceramic coating layer and the intermediate layer oxidizes, causing the ceramic coating layer and the intermediate layer to oxidize. The cause is a decrease in adhesion with the intermediate layer. Such problems reduce the reliability of the TBC. On the other hand, as the temperature of gas turbines increases. T
The heat shielding effect required of BC increases. That is, in order to increase the heat shielding effect, it is necessary to increase the thickness of the ceramic coating layer. In this case, thermal stress caused by thermal cycles and the like naturally increases. It is necessary to improve the durability of the ceramic coating by alleviating the thermal stress that occurs in the ceramic coating layer due to thermal cycling, etc. Furthermore, when a TBC with low reliability is provided on a rotor blade, peeling of the ceramic layer reduces the heat shielding properties and increases the blade temperature, significantly reducing the reliability of the rotor blade. Furthermore, the heat shielding properties of the TBC are most required near the leading edge. Since the heat transfer rate from combustion gas to the rotor blade is low in the dorsal and ventral parts of the blade, the temperature of these parts is lower than that of the leading edge. Therefore, it is necessary to provide a TBC with excellent heat shielding properties and high durability at the leading edge of the rotor blade. Further, the dorsal and ventral sides of the blades determine the spacing between adjacent blades, and the spacing between these portions becomes a flow field for the combustion gas flow, so it is a factor that controls turbine performance. On the other hand, the area near the leading edge is not the main factor determining the flow field of the combustion gas flow.

Therefore, in order to obtain high-performance turbine rotor blades, a TBC with excellent high-temperature durability and high heat shielding properties is required near the leading edge, while on the back and ventral sides, where the heat load is small, the heat shielding properties are poorer. Rather, a coating is needed that reduces fluctuations in the flow field of the combustion gas stream.

[Problem to be solved by the invention]

As described above, in order to obtain high-performance turbine rotor blades, first of all, a TBC with excellent high-temperature durability and great heat shielding properties is required. Here, the TBC provided with an intermediate layer is intended to relieve the thermal stress generated between the ceramic rIi layer and the base material, but since the intermediate layer does not have sufficient high temperature oxidation resistance, Under high temperature conditions, the thermal stress relaxation effect of the intermediate layer was not necessarily sufficient. The intermediate layer also does not necessarily have sufficient high-temperature corrosion resistance. The purpose of the present invention is to sufficiently exhibit the thermal stress relaxation effect, which is the original purpose of the intermediate layer, which is a mixed layer of ceramic and metal, even under high-temperature oxidation and high-temperature corrosion conditions, and to reduce the spacing between adjacent rotor blades. Ceramic is a ceramic material that can be easily manufactured and maintained stably for a long period of time, allowing the flow field of combustion gas to be maintained stably for a long period of time, and overall turbine performance can be maintained at high performance and stably for a long period of time. Our objective is to provide a high-performance turbine rotor blade with a coating layer. [Means for Solving the Problems] The present invention provides a structure in which an alloy layer made of an alloy having excellent high-temperature oxidation resistance and high-temperature corrosion resistance is provided between a ceramic coating layer and an intermediate layer consisting of a ceramic/metal mixed layer. A TBC is provided near the leading edge of the rotor blade.

That is, the ceramic-coated turbine rotor blade according to the present invention includes a rotor blade base material made of a heat-resistant alloy whose main components are at least one of nickel, cobalt, and iron, and a green portion of the rotor blade base material that is coated on the front green portion of the blade. the coating layer comprises a ceramic layer, a mixed layer made of a mixture of ceramic and metal and provided between the ceramic layer and the rotor blade base material, and the mixed layer and the ceramic layer and an alloy layer made of an alloy material having higher high-temperature oxidation resistance and high-temperature corrosion resistance than the rotor blade base material.

Further, the turbine rotor blade according to the present invention includes a rotor blade base material made of a heat-resistant alloy whose main components are at least one of nickel, cobalt, and iron, and a coating provided on the leading edge portion of the rotor blade base material. a layer, the coating layer comprising a ceramic layer, a mixed layer made of a mixture of ceramic and metal and provided between the ceramic layer and the rotor blade base material, and a layer between the mixed layer and the ceramic layer. and an alloy layer made of an alloy material that is provided between the mixed layer and the rotor blade base material and has better high-temperature oxidation resistance and high-temperature corrosion resistance than the rotor blade base material.

The rotor blade preferably further includes an oxide layer containing aluminum as a main component at the boundary between the alloy layer and the ceramic layer.

Further, the turbine rotor blade according to the present invention includes a rotor blade base material made of a heat-resistant alloy whose main components are at least one of nickel, cobalt, and iron, and a front blade provided on the leading edge portion of the rotor blade base material. an edge coating layer, and a trailing edge coating layer provided on a portion of the rotor blade base material other than the portion covered with the leading edge coating layer, and the leading edge coating layer includes a ceramic layer, the ceramic layer and the trailing edge coating layer. A mixed layer made of a mixture of ceramic and metal provided between the rotor blade base material, and a mixed layer provided between the mixed layer and the ceramic layer and having higher temperature oxidation resistance and high temperature corrosion resistance than the rotor blade base material. an alloy layer made of an alloy material with excellent properties, and the trailing edge coating layer is formed of a single alloy layer or a double layer of an alloy layer and a ceramic layer, and is thinner than the leading edge coating layer. This is what is being done. Here, both ends of the mixed layer are preferably covered with an alloy layer.

Further, in the rotor blade, the thickness of the ceramic layer is 0.
．． 05~L. Oram. The thickness of the alloy layer is 0.
03~0.5mm. The thickness of the mixed layer is 0.03~0
．． 51III+ is preferable.

In the rotor blade, the material forming the alloy layer includes at least one of cobalt or nickel, chromium, and aluminum, and further includes at least one of hafnium, tantalum, yttrium, silicon, and zirconium.

According to the present invention, high-temperature oxidation and high-temperature corrosion of the ceramic-metal mixed layer under severe conditions at the leading edge of the blade are prevented by the alloy layer provided between the ceramic layer and the mixed layer. As a result, the mixed layer is stable even under high-temperature oxidation and high-temperature corrosion conditions, and can fully exhibit its original function of alleviating thermal stress between the ceramic layer and the base material.

In this way, ceramic coatings whose thermal stress relaxation effect is stable even under high-temperature oxidation and high-temperature corrosion conditions have improved durability compared to conventional ceramic coatings. Furthermore, even if the thickness of the ceramic layer is increased to improve the heat shielding effect, the decrease in durability will be small, and the temperature of the moving blade material near the leading edge of the blade, where the amount of human heat from combustion gas is greatest, will be reduced for a long time. Can be maintained stably for a period of time.

Furthermore, the mixed layer has a lower thermal conductivity than the alloy layer, and although its contribution is smaller than that of the ceramic layer, it can serve as a thermal resistance in obtaining heat shielding properties.

Furthermore, the same effect can be obtained by providing the alloy layer between the ceramic layer and the intermediate layer made of the mixture, and further providing an oxide layer containing AN as a main component at the boundary between the alloy metal and the ceramic layer. is obtained. Furthermore, by providing an oxide layer containing AQ as a main component, the ceramic coating can be improved!
It is also expected to improve the adhesion between iN and metal.

[Effect]

In the present invention, in the TBC provided near the leading edge of the rotor blade, the alloy layer provided between the ceramic coating layer and the intermediate layer made of a ceramic-metal mixture prevents oxidation and oxidation that progresses through the porous ceramic coating layer. It has the effect of protecting the intermediate layer against corrosion. That is, the intermediate layer is made of a mixture of ceramic particles and metal particles, and its coefficient of thermal expansion is between that of ceramic and metal, and has the effect of relieving thermal stress between the ceramic coating layer and the base material. .

However, the intermediate layer made of this mixture has poor high-temperature oxidation resistance and high-temperature corrosion resistance, so in a thermal stress relaxation type ceramic coating provided with an intermediate layer, it is necessary to improve the high-temperature oxidation resistance and high-temperature corrosion resistance of the intermediate layer.

The high-performance gas turbine rotor blade of the present invention has excellent high-temperature durability and has a large heat shielding property as described above by providing the TBC near the leading edge of the blade. The reliability of the leading edge can be improved. Furthermore, it is possible to form the coating layer thinner in areas other than the leading edge of the rotor blade, thereby reducing the distance between adjacent blades.
It can be manufactured without considering the addition of the coating layer, and is excellent in terms of manufacturing and long-term stability. To explain the effect of not providing a thick ceramic coating like the leading edge on the back and vent sides of the turbine rotor blade,
It is as follows. Turbine performance is determined by the gap between the dorsal and ventral sides of adjacent blades. This gap is an important value in turbine design, and if a thick ceramic coating is to be provided, the blade dimensions must be determined in advance by taking the coating thickness into consideration. Because high-performance rotor blades have a structure in which the inside of the blade is air-cooled, the thickness of the dorsal and ventral blade bases is several mm, and it is difficult to adjust the gap by grinding the blade base surface due to the strength design of the base body. . Therefore, changes are required from the stage of precision casting of R. In that case, in order to apply a ceramic coating to the current uncoated blade, it would be necessary to modify the mold, which would increase costs. Further, when using a gap-adjustable blade in this manner, when the coating becomes wear-and-tear, the gap increases and turbine performance deteriorates.

In the present invention, since the coating on the back and belly is thin, there is no need for gap adjustment, and turbine performance can be maintained stably for a long period of time.

〔Example〕

The details of the present invention will be explained below using examples.

FIG. 1 is a perspective view of a ceramic coated rotor blade according to an embodiment of the present invention, and FIG. 2 is a schematic cross-sectional view thereof. FIG. 3 shows a sectional view of the TBC in the vicinity of the blade leading edge 6 of the high performance gas turbine rotor blade of the present invention shown in FIG. Figures 4 and 7 show schematic cross-sectional views of conventional ceramic coatings. In Figures 3 to 5, 11 is a ceramic layer, 12 is a ceramic layer;
13 is an alloy layer made of an alloy having better high temperature oxidation resistance and high temperature corrosion resistance than the base material 12, and 14 is an alloy layer of the above alloy and the above ceramic. The material constituting the ceramic 11 is mainly composed of ZrO2, which has low thermal conductivity, and Y20
,, ZrO-based ceramic to which MgO, CaO, etc. have been added. The material forming the alloy M13 is Co or Ni.
Either one or a combination thereof contains Cr, AQ, and further contains Hf, Ta, Y, Si, Z
It is an alloy material containing one or more of r.
The mixed layer 14 is made of a mixture of the above-mentioned ZrO2 ceramic and alloy material. In the TBC of Figure 3, 2
The components of the alloy layers 1 and 3 may be the same, or may be made of alloys of different precepts. Although there are no particular restrictions on the form or method of forming each of these coating layers, plasma spraying is preferred from the viewpoint of high coating speed and workability. Note that an electron beam evaporation method or a sputtering method may be used as a method for forming a relatively thin coating layer such as an alloy layer. Table 1 shows the results of a thermal cycle test on the ceramic coating of the leading edge of the present invention and a conventional ceramic coating for comparison. In Table 1, No. 1'' NCL8 is the conventional ceramic coating, and &9 to Nα23 are the ceramic coatings of the entire front part of the blade of the present invention.The thermal cycle test was repeated at 170°C and 1000°C, and the damage to the ceramic coating was evaluated. In the ceramic coating of the blade leading edge of the present invention, the thickness of the ceramic [11] is desirably 1.Onwn or less.As shown in Nα13 in Table 1, the thickness of the ceramic layer↓1 If it is 1++n or more, the durability in the heat cycle test tends to decrease.The thickness of the alloy layer 3 (alloy layer I in Table 1) between the ceramic M11 and the mixed layer 14 is 0.03 A range of ~0.5 kaku is desirable. P& in Table 1
114,N (such as 118).If the thickness of the alloy layer 2 is outside the above range, the durability in thermal cycle tests tends to decrease.If the thickness of the alloy 1r is thin, the ceramic l
1 is no longer sufficient as a layer to prevent oxidation or corrosion. On the other hand, if the thickness of the alloy Jll is too thick, the alloy J'ila itself becomes a layer that generates new thermal stress, canceling out the thermal stress relaxation effect of the mixed layer 14.

Next, the thickness of the mixed layer l4 is preferably in the range of 0.03 to 0.5 m. If the thickness of the mixed layer 14 is outside the above range, as in N(119,Nl123 in Table 1), the durability in the thermal cycle test will decrease.If the thickness of the mixed layer 14 is thin,
The thermal stress relaxing effect of the mixed layer 14 becomes insufficient. On the other hand, if it is too thick, the strength of the mixed layer 14 itself will be lower than that of the alloy M13.
etc., it cannot withstand the thermal stress in the mixture Nl4 caused by the thickening of the mixture layer 14. The thickness of alloy layer (1) in Table 1 is not particularly limited, but is preferably in the range of 0.03 to 0.5 mm.

The reason for this is almost the same as that for alloy layer (2) in Table 1.

In addition, in the mixed layer 14 of ceramic and metal, the mixing ratio is not particularly limited. The mixing ratio of the mixed layer 14 in Table 1 is the cross-sectional structure II! According to the area ratio, the metal/ceramic ratio is 2/1. The present inventors have developed a mixture M with other mixing ratios.
14 was also investigated, and the results were almost the same as in Table 1 at other mixing ratios. In addition, we also investigated a method in which the mixing ratio of the mixed layer 14 was gradually changed from one containing a large amount of metal to one containing a large amount of ceramic, which can be inferred from the present invention, but the effect was hardly clear, and uniform mixing was not achieved. It was almost equivalent to that provided with a mixed layer 14 of the same ratio.

Next, after performing a high temperature oxidation test, a similar thermal cycle test was performed. High temperature oxidation test: 1000”C, 500h
It is. As a result, the test pieces coated with ceramics &5 to 8 in Table 1 were found to be ceramic J' in the oxidation test.
ill was damaged and peeled off. On the other hand, as a result of the thermal cycle test for the other test pieces, the number of damages to the ceramic coating of the Nα1 to Nα4 test pieces was reduced by about 20 to 40%, and the durability was decreased. The ceramic coating on the leading edge of the blade within the scope of the present invention in Table 1 is almost the same as the results in Table 1, and in some test specimens, the number of times it takes for the ceramic coating to become damaged has actually increased. was also recognized.

Next, we conducted a high-temperature corrosion test using the molten salt coating method. The test method was to apply 25% NaCfl-75% Na, SO4 molten salt and heat it in the air at 850'C for 300 hours. Afterwards, a similar thermal cycle test was conducted.

As a result, the ceramic coating of the test pieces with Nα5 to Nα8 in Table 1 was damaged after the high-temperature corrosion test. On the other hand, as a result of the thermal cycle test, the test pieces with Na 1 to 4 in Table 1 showed that the number of occurrences of damage to the ceramic coating was reduced by about 20 to 40%, and the durability was slightly lowered. The ceramic coating for the leading edge of the blade within the scope of the present invention in Table 1 is as follows:
Compared to the results in Table 1, the number of occurrences of damage to the ceramic coating was almost the same, and no particular decrease in durability was observed.

In addition, in the ceramic coating of the present invention described above, there is no particular restriction on the method for producing the alloy layer 13, but the atmosphere around the plasma jet is a protective gas or an inert gas, and the atmosphere is reduced to below atmospheric pressure. It is preferable to use atmospheric plasma spraying. The same applies to the mixed layer l4 of ceramic and metal. The alloy layer 13 formed by plasma spraying in a reduced-pressure atmosphere is less susceptible to oxidation of the alloy powder during spraying, and the alloy N13 becomes a coating layer with a dense structure that does not contain contaminants such as oxide films.

Also, in the mixed layer 14, oxidation of the alloy powder constituting the mixture is difficult to occur, and the metal portion in the mixed layer 14 becomes a Fll layer in which contaminants such as oxide films are not mixed.

In addition, in the embodiment of the present invention shown in FIG. 3, when used for a long time under high temperature oxidation conditions, an oxide layer (mainly composed of AQ) is formed at the boundary between the ceramic layer 11 and the alloy layer 13 during use.
(not shown) is formed.

As described above, in the conventionally known ceramic coating, the intermediate layer made of a mixture of metal and ceramic is effective at high temperatures or Under high-temperature corrosion conditions, the intermediate layer itself is damaged due to high-temperature oxidation and high-temperature corrosion.
It is not able to exert its main thermal stress relaxation effect, but instead generates new thermal stress, and for example, in thermal cycle tests, its durability is lower than that of a ceramic coating without an intermediate layer. .

On the other hand, in the ceramic coating of the present invention, the mixed layer 1
4, the thermal stress relaxation effect is stably maintained even under high temperature or high temperature corrosion conditions, and is effective in improving the durability of the ceramic coating. In addition, 1 liter of ceramic layer
Even if the thickness is increased, there is little decrease in durability.
This is a high-performance ceramic coating with a large heat shielding effect. FIG. 6 shows the relationship between the ceramic layer thickness of the ceramic coating and the heat shield temperature, which was obtained based on the thermal conditions of the front weave of the turbine rotor blade. In Figure 6, 2 shows the result of the ceramic coating on the leading edge of the blade of the present invention, and 20 shows the result of the conventional ceramic coating. The ceramic coating on the leading edge of the blade of the present invention has a ceramic-metal mixed layer thickness of 0.3 no. Due to the thermal resistance of the part, the heat shield temperature is approximately twice as high as that of a conventional ceramic coating even if the thickness of the ceramic layer is the same. As described above, the ceramic coating on the leading edge of the blade of the present invention exhibits excellent heat shielding properties.

Examples of the present invention will be described in detail below.

Example 1 Using a turbine rotor blade made of IN-738, which is a Ni-based alloy, as shown in Fig. 4, its surface was degreased, plasted using alumina grit, and then plasma sprayed. Weight% Ni - 21% by weight Cr - 8% by weight A
A coating layer of an alloy material consisting of fl-0.5% by weight Y and the balance Co was formed. Plasma spraying is 200 Torr
The test was carried out in an Ar atmosphere at a pressure of . The plasma output is 4
It is 0kW. Under these conditions, the alloy coating layer with a thickness of 0.1 mm was shaped into an alloy layer.・After that, the area other than the area near the leading edge 6 of the blade shown in FIG.
A mixture of ceramic powder of component Y203 and alloy powder of the above-mentioned composition was thermally sprayed. Mixed? The ratios are shown in Table 2.
Further, the thermal spraying conditions are also the same as those for forming the alloy layer 13 described above. In this way, a mixed layer 14 made of a mixture of ceramic and metal was formed on the alloy layer 13. The thickness of this mixed layer 14 is 0.3 nn. The thermal spraying conditions are the same as those for producing the alloy layer 13 described above. FIG. 7 shows masking 15 and mixing M14. Thereafter, the masking position was changed, and the alloy powder having the above-mentioned composition was thermally sprayed onto the mixed layer 14 under the same working conditions as the above-mentioned alloy layer 13, to a thickness of 0.1 NW.
An alloy layer 13 was formed.

FIG. 8 shows the masking 15 and the alloy layer 13.

After that, the masking position was changed and the alloy layer 1 was further removed.
On top of No. 3, ZrO2-8% by weight Y20 powder was thermally sprayed. The thermal spraying conditions were a plasma output of 50 kW and thermal spraying in the atmosphere. ZrO2-8% by weight y, o, thickness of the coating layer is 0.
It is 4nn. FIG. 9 shows masking 15 and ceramic layer 11. FIG. After that, heat treatment is performed in vacuum at 1120°C for 2 hours to remove the alloy layer 13 in contact with the base material 12 and the base material processing 2.
We performed diffusion processing with Table 2 Number of occurrences of damage to ceramic coating l) Heat cycle test: 1000°C → 170°C2) High temperature oxidation test: 1
000℃, 500h (heated in air) 3) High temperature corrosion test: 850℃. 300h (25%Na
CQ + 75% Na, So4) 4) M/C: Metal/ceramic volume ratio The ceramic-coated turbine rotor blade of the present invention manufactured by such a method is shown in FIG. 1 near the leading edge of the blade in FIG. The turbine rotor blade has a ceramic coating with high durability and high heat shielding properties, and the dorsal and ventral parts with a small heat load have an alloy layer 13 shown in FIG. 5. A thermal cycle test similar to that described above was carried out on the turbine rotor blade with a ceramic coating on the leading edge of the blade of the present invention manufactured by such a method. As a result, the number of repetitions until the ceramic coating was damaged was as shown in Table 2. Also, in a high temperature oxidation test by heating in the air at 1000°C for 500 hours, no damage was observed to any of the ceramic coatings after the test. Furthermore, as a result of carrying out the same thermal cycle test as described above using these test pieces, the number of repetitions until the ceramic coating was damaged was as shown in Table 2. Next, 25% NaCf
1 + 75% Na2SO4 molten salt, 850℃, 3
No damage was observed to any of the ceramic coatings even after a high-temperature corrosion test in which heating was performed in the air for 00 hours.

Example 2 A turbine rotor blade similar to that in Example 1 was pretreated in the same manner as in Example 1, and then an alloy layer and a mixed layer were formed in the same manner using the same materials as in Example 1. Intimidated. The mixing ratio of ceramic and metal in the mixed layer was 1:1.
The thickness of each is also similar. After that, 32% by weight N
i-21 wt% Cr-8 wt% Afl-0.5 wt% Y
Using an alloy material with a balance of CO as a target, a layer of 0.02 m thick was deposited on the above-mentioned intermediate layer by sputtering.
An alloy layer of Otori was formed. The sputtering conditions were an applied voltage of 2 kV and a processing time of 2. Oh. 'Thereafter, a ceramic layer was formed in the same manner as in Example 1.

Thereafter, a heat treatment was performed in vacuum at 1120° C. for 2 hours to obtain a diffusion treatment. A durability test similar to that of Example 1 was conducted on the ceramic-coated heat-resistant rotor blade of the present invention manufactured in this way, and almost the same results were obtained.

Example 3 A ceramic-coated heat-resistant member was produced using the same materials as in Example 1 and in the same manner as in Example 1. After that, 950
C. for 20 hours in the air to form an oxide layer containing Afl,03 as the main component at the boundary between the ceramic and the alloy layer. As a result of cross-sectional structure observation of the test piece, its thickness was approximately 5 μm.

or. As a result of XMAp observation, in the part corresponding to the oxide layer,
The presence of many AQ and O was observed, and some Cr was also observed. A durability test similar to that in Example 1 was conducted using the leading edge ceramic-coated heat-resistant rotor blade thus produced. As a result, almost the same performance as in Example 1 was obtained.

Example 4 Using the same turbine rotor blade as in Example 1, pretreatment was performed in the same manner as in Example 1, and then an alloy layer, a mixed layer, Furthermore, an alloy layer was formed thereon. Note that the mixing ratio of ceramic and metal in the mixed layer is 1:1. The thickness of each is also similar.

Thereafter, a ceramic layer similar to that in Example 1 was formed on the alloy layer without using a masking material. In this case, the ceramic layer was formed over the entire blade surface. As a result, the boundary between the ceramic leading edge coating layer with high durability and high heat shielding properties near the leading edge of the wing and the thin trailing edge coating layer on the dorsal side of the wing or ventral side of the wing is shown in Figure 10. It seemed to be shown in . The ceramic-coated rotor blade of the present invention formed in this way has high durability and high heat shielding properties in the vicinity of the leading edge, which is exposed to harsh environmental conditions with a large heat load.

〔Effect of the invention〕

As explained above, the ceramic coating of the present invention has a structure in which an alloy metal with excellent high-temperature oxidation resistance and high-temperature corrosion resistance is provided between the ceramic layer and the ceramic/metal mixed layer, thereby alleviating thermal stress in the mixed layer. The effect can be fully exerted. As a result, even if the thickness of the ceramic layer is increased, the decrease in durability is small, and the heat shielding properties, which depend on the thickness of the ceramic layer, are increased, and the thermal resistance of the mixed layer also contributes to the heat shielding properties. , resulting in a highly durable coating with excellent heat shielding properties. In the ceramic-coated turbine rotor blade of the present invention, in which a ceramic coating with such characteristics is provided near the leading edge of the turbine blade, which is exposed to a large heat load and a harsh environment, the leading edge of the Due to the characteristics, the temperature of the rotor blade base decreases,
Improved wing reliability. Furthermore, the amount of air for cooling the blades can be reduced, improving turbine efficiency. Furthermore, by reducing the thickness of the coating on the dorsal and ventral sides of the blade, which control the area of the combustion gas flow field, manufacturing becomes easier and stable turbine performance can be achieved over a long period of time. In other words, in order to set the distance between adjacent blades to the required size for turbine design reasons, the thickness of the blade itself must be formed with high precision, but as mentioned above, the coating on the trailing edge side of the blade is By making it thinner, it becomes easier to set the dimensions of adjacent wing dorsal and ventral sides. Furthermore, even if the coating in that area is damaged, the decrease in turbine efficiency can be minimized because the coating is thin. As described above, the ceramic-coated turbine rotor blade of the present invention exhibits the effects of improving both the reliability of the turbine rotor blade and the turbine efficiency.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a turbine rotor blade according to the present invention, FIG. 2 is a schematic cross-sectional view taken along line 1 in FIG. FIGS. 4 and 5 are enlarged sectional views of main parts of the back side or vent side of the turbine rotor blade according to the present invention, FIG. 6 is a heat shielding characteristic diagram of the coating layer, and FIGS. Figure 9 is a sectional view of the main parts of each process showing the manufacturing process, and Figure 10 is
11 is a perspective view of a conventional turbine rotor blade, FIG. 12 is a sectional view taken along the line Xll-Xll of FIG. 11, and FIG. 13 is a turbine rotor blade. The heat transfer coefficient distribution diagram of combustion gas with respect to the plane of the blade, FIG. 14, also shows a perspective view of a conventional turbine rotor blade. 1... Wing leading edge, 2...
... Wing dorsal side, 3... Wing dorsal side trailing edge, 4... Wing ventral side, 5
... Wing ventral trailing edge, 6... Near one wing leading edge, 7... Wing dorsal side, 8... Wing ventral side, l1... Ceramic layer,
12... Moving blade base, 13... Alloy layer, 14... Ceramic/metal mixed layer, 15... Masking material, 2o
...Thermal barrier properties of conventional ceramic coating, 21
...Heat shielding properties of the ceramic coating near the leading edge of the ceramic-coated rotor blade of the present invention. Figure 1 Figure 2 Figure 113 Figure 4 Figure 5

Claims (7)

[Claims] 1. A rotor blade base material made of a heat-resistant alloy containing at least one of nickel, cobalt, and iron as a main component, and a coating layer provided on the blade leading edge portion of the rotor blade base material, and the coating layer is a ceramic layer. a mixed layer made of a mixture of ceramic and metal provided between the ceramic layer and the rotor blade base material; and a mixed layer provided between the mixed layer and the ceramic layer and having a higher temperature than the rotor blade base material. A ceramic-coated turbine rotor blade comprising an alloy layer made of an alloy material with excellent oxidation resistance and high temperature corrosion resistance. 2. A rotor blade base material made of a heat-resistant alloy containing at least one of nickel, cobalt, and iron as a main component, and a coating layer provided on the blade leading edge portion of the rotor blade base material, and the coating layer is a ceramic layer. and a mixed layer made of a mixture of ceramic and metal provided between the ceramic layer and the rotor blade base material, between the mixed layer and the ceramic layer, and between the mixed layer and the rotor blade base material. A ceramic-coated turbine rotor blade, comprising: an alloy layer made of an alloy material having better high-temperature oxidation resistance and high-temperature corrosion resistance than the rotor blade base material. 3. The ceramic-coated turbine rotor blade according to claim 1 or 2, further comprising an oxide layer containing aluminum as a main component at the boundary between the alloy layer and the ceramic layer. 4. A rotor blade base material made of a heat-resistant alloy containing at least one of nickel, cobalt, and iron as a main component; a leading edge coating layer provided on a blade leading edge portion of the rotor blade base material; a trailing edge coating layer provided on a portion other than the portion covered with the leading edge coating layer, and the leading edge coating layer includes a ceramic layer and a ceramic layer provided between the ceramic layer and the rotor blade base material. A mixed layer made of a mixture with a metal, and an alloy layer made of an alloy material that is provided between the mixed layer and the ceramic layer and has better high-temperature oxidation resistance and high-temperature corrosion resistance than the rotor blade base material. The ceramic-coated turbine rotor blade is provided with a ceramic-coated turbine rotor blade, wherein the trailing edge coating layer is formed of a single alloy layer or two layers of an alloy layer and a ceramic layer, and is formed to have a thinner wall thickness than the leading edge coating layer. 5. 5. The ceramic-coated turbine rotor blade of claim 4, wherein both ends of the mixed layer are covered with an alloy layer. 6. In claim 1 or 2, the thickness of the ceramic layer is 0.05 to 1.0 mm, and the thickness of the alloy layer is 0.0 mm.
3~0.5mm, the thickness of the mixed layer is 0.03~0.5
Ceramic coated turbine rotor blade in mm. 7. In claim 1, the material constituting the alloy layer includes at least one of cobalt or nickel, chromium, and aluminum, and further includes at least one of hafnium, tantalum, yttrium, silicon, and zirconium.
Ceramic-coated turbine rotor blades.