JPH0411620B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a jet engine combustor used in high temperature or high temperature corrosive environments and a method for manufacturing the same. [Prior Art] In order to improve the power generation efficiency of gas turbine plants for power generation, studies have been conducted to coat the surfaces of gas turbine members with heat-resistant materials to improve their heat resistance. One method is to coat the surface of the metal member with ceramic having low thermal conductivity. Such coatings are called Thermal Barrier Coatings.
(hereinafter abbreviated as TBC). One such means
For example, JP-A-55-112804 discloses that in order to increase the adhesion of the coating layer, another metal bonding layer is previously formed on the surface of the gas turbine member, and then a ceramic coating layer is formed. The purpose of the bonding layer is to alleviate the difference in physical properties between the base material and the ceramic coating layer. The present invention also applies a heat shield coating to a jet engine combustor. [Problems to be Solved by the Invention] The present inventors studied TBCs made of various conventionally used materials. For example, a high-temperature oxidation test of TBC was conducted using a TBC consisting of a ZrO ₂ ceramic coating layer and a bonding layer made of a metal alloy material. This test considered the installation of TBC in a jet engine combustor used under high temperature conditions. As a result, it was found that in conventional TBC, oxidation at the interface between the ZrO ₂ coating layer and the bonding layer progressed significantly. As a result of determining the adhesion of TBC before and after the test, we found that in an oxidation test at 1000℃ for 500 hours,
The adhesion strength of the interface between the ZrO _2- based coating layer and the bonding layer is 1/2~
It was found that it decreased to 1/4. Although this decrease in adhesion varies slightly depending on the thickness and porosity of the ZrO ₂ -based coating layer, as well as the type and amount of additives added to ZrO ₂ , the decrease is significant in all cases. . There were also some differences in the composition of the alloy material in the bonding layer, but all of them were reduced. Such a decrease in interfacial adhesion becomes more significant as the temperature of the oxidation test becomes higher or as the test time increases. In the 1100℃, 100 hour test, some
In some cases, peeling damage from the interface was observed.
On the other hand, in TBC using a mixture of a metal alloy material and a ZrO ₂ -based material as an intermediate layer, the decrease in adhesion in the oxidation test was even more remarkable. These results also correspond to the results of high-temperature thermal cycle tests conducted by the present inventors. i.e. 970
℃, 1020℃, 1070℃, 1120℃ respectively.
Even in a test in which the test was held for 30 minutes and repeatedly cooled to 150°C by air cooling, the number of repetitions until TBC damage occurred decreased significantly as the test temperature increased. These problems with conventional TBCs are a serious obstacle to obtaining highly reliable TBCs that can cope with the high temperatures of jet engine combustors. In other words, when implementing TBC for the purpose of preventing the base material temperature of the jet engine combustor from increasing and reducing the temperature,
In conventional TBC-treated parts, TBC has low high-temperature durability, so it is difficult to sufficiently reduce the base material temperature of the part. Therefore, the present inventors investigated a jet engine combustor in which a TBC with excellent high-temperature durability was installed instead of the conventional TBC, which can sufficiently reduce the base material temperature even under high-temperature operating conditions. That is, the present inventors took the above points into consideration and came up with the invention of a jet engine combustor having a TBC with excellent durability. An object of the present invention is to improve the reliability of TBC. That is, the object is to provide a TBC in which the bonding strength between the ceramic material and the base material is stable over a long period of time, and is less prone to cracking or peeling. [Means for Solving the Problems] The present invention provides a bonding layer of an alloy that has better high-temperature oxidation resistance and high-temperature corrosion resistance than the base material on the liner base material of a jet engine combustor made of a metal material. A ceramic coating layer is formed on the alloy bonding layer, and an oxide layer containing Al as a main component is previously formed at the boundary between the alloy bonding layer and the ceramic coating layer. The base material is preferably a Ni-based gold containing 35 to 61% by weight of Ni, 1 to 3% by weight of Co, and 14 to 27% by weight of Fe. The bonding layer is mainly composed of Ni or Co, and contains 10~10% of Cr.
An alloy containing 30% by weight and 5 to 30% by weight of Al is desirable. It is even more desirable to further include 0.1 to 5% by weight of one or more of Hf, Ta, Y, Si, and Zr. The ceramic layer is mainly composed of ZrO ₂ and CaO.
Preferably, it contains one of MgO and Y ₂ O ₃ . CaO
The amount of MgO is 4 to 10% by weight, the amount of MgO is 8 to 24% by weight,
The amount of Y ₂ O ₃ is preferably 4 to 20% by weight. CaO and
It is also possible to add two or more of MgO and Y ₂ O ₃ in combination. [Function] According to the present invention, the oxide layer containing Al as a main component is stable even in a high-temperature atmosphere, which prevents the progress of oxidation of the alloy bonding layer, and also has strong bonding strength with the ceramic coating layer. Therefore, even after long-term use, cracks may occur in the ceramic coating layer.
Peeling can be prevented. [Example] The details of the present invention will be described below. First of all,
We examined the problems of conventional TBC in detail and investigated their causes. The cross-sectional structures of TBCs subjected to various oxidation tests were observed. An example of the results is shown in FIGS. 5 and 6.
These microstructure photographs show the cross section of the bonding layer at a magnification of 100 times, and in FIG. 5, a defect has occurred at the interface between the ZrO ₂ -based coating layer and the bonding layer. FIG. 6 shows the results of TBC in which a mixed layer of alloy material and ZrO ₂ -based material was formed between the bonding layer and the ZrO ₂ -based coating layer. In this case, the alloy material of the intermediate layer is significantly oxidized. These phenomena are also observed in high temperature thermal cycle tests. That is, in TBC, a problem arises in that the alloy coating layer or intermediate layer below the bonding layer is oxidized through the ZrO ₂ -based coating layer, which has a porous or micro-cracks structure to relieve thermal stress. This kind of oxidation significantly reduces the adhesion of the interface and causes it to break away from the interface due to thermal stress, etc.
Avulsion damage will occur to the TBC. The cause of such interface oxidation is ZrO ₂ at high temperature.
The system material becomes a semiconductor, facilitating the movement of oxygen,
An increase in oxygen partial pressure at the interface is also considered to be an important factor. Such oxidation is considered to be more accelerated when an intermediate layer is formed, for example, because the area of the interface increases. Traditional
As a result of analyzing the state of the interface of TBC, it was found that an oxide mainly composed of Cr was formed at the interface.
Since such Cr-based oxides are unstable at high temperatures, damage occurs from the parts where the oxides are formed. Therefore, in the liner of a jet engine combustor, it is necessary to fully consider oxidation at the interface. From this viewpoint, the present inventors investigated various methods and found that it is promising to form a densely structured oxide thin film containing Al as a main component at the interface. Al-based oxides are stable at high temperatures, and
Unlike _ZrO2 -based materials, it does not become a semiconductor at high temperatures.
Therefore, a thin film of Al-based oxide is effective as a barrier to prevent internal oxidation. On the other hand, when such an Al-based oxide layer is thick, it becomes a new intermediate layer that reflects the physical properties of the Al-based oxide. As a result, the Al-based oxide layer will be damaged due to thermal stress or the like. On the other hand, if it is too thin, it cannot serve as a barrier that satisfies the internal antioxidant effect. Therefore, it is desirable that the thickness is 0.1 μm or more and 20 μm or less. Al in this range
The based oxide layer serves well as a barrier layer to prevent internal oxidation of the bonding layer. On the other hand, something like this
Another important effect of the thin layer of Al-based oxide is
It was discovered that the adhesion between ZrO ₂ ceramic and the bonding layer can be improved. i.e. traditional TBC
In contrast, the ZrO ₂ ceramic and the metal alloy constituting the bonding layer were mechanically bonded.
The adhesion between the ZrO ₂ ceramic and the bonding layer is due to the interface between the oxides, Al-based oxide and ZrO ₂ -based ceramic, and the Al-based oxide generated from the Al component in the metal alloy that makes up the bonding layer. , the adhesion mechanism becomes extremely strong. As an example, TBC with a thin film of such Al-based oxide
In an oxidation test at 1000°C for 500 hours, the adhesion between the bonding layer and the ZrO ₂ ceramic coating layer remained at 7 Kg/mm ² or more with almost no decrease. Figure 1 shows an example of the cross-sectional structure of TBC after a high-temperature oxidation test, and the magnification is
It is 100 times more. In FIG. 1, there are no defects at the interface between the ZrO ₂ ceramic coating layer and the bonding layer. Also, in the oxidation test at 1100°C for 100 hours, no decrease in adhesion or occurrence of defects at the interface was observed. Furthermore, 1030℃, 1070℃,
Hold at 1120℃ and 1170℃ for 30 minutes.
Table 1 shows the results of a test in which air cooling was repeated to 150°C.

[Table] Samples No. 201-204 in Table 1 are conventional TBC, No. 205-
208 is the result of TBC with a thin film of Al-based oxide. As a result, TBC with a thin film of Al-based oxide
The number of repetitions required for TBC to become damaged was approximately 3 to 7 times that of conventional TBC. Moreover, as the test temperature becomes higher, the effect becomes more pronounced. As described above, the TBC having a thin film of Al-based oxide discovered by the present inventors is particularly effective under high-temperature conditions. A jet engine combustor liner with such TBC can be stable even under high temperature conditions. Furthermore, TBC with a ZrO ₂ -based coating layer bonded via a thin film of Al-based oxide.
In this case, the adhesion strength of the ZrO ₂ based coating layer is 7 Kg/mm ² or more. This adhesion force is much greater than that of the ZrO ₂ -based coating layer of conventional TBC, which was about 3 to 5 kg/mm ² . We investigated the effects of applying TBC in this way. In a jet engine combustor, by applying TBC with excellent high-temperature durability as described above on the facing surfaces of the outer liner and inner liner that are exposed to high-temperature combustion gas, the temperature of the base material can be stably reduced. becomes possible.
On the other hand, in liners with conventional TBC, the TBC is damaged in a short period of time, especially in areas where the base material temperature is high.
TBC damage becomes significant. the result,
The effect of TBC in reducing the temperature of the base material disappears, and the temperature of the base material increases, leading to damage to the liner. In the combustor liner, the base material vibrates due to combustion, and the adhesion of the ceramic coating layer decreases under high temperature conditions.
The TBC becomes even more susceptible to damage. Therefore, it becomes impossible to exert sufficient effects on the areas where TBC's effects are most needed. and,
There is a possibility that the temperature of the base material may be higher in the damaged part of the TBC than in other parts where the TBC is healthy. For areas where the base material temperature is high, liners made with conventional TBC are unreliable.
On the other hand, in the liner of the present invention in which TBC with a thin film of Al-based oxide is constructed, TBC has excellent durability especially at high temperatures, so damage to the TBC does not occur in areas where the temperature of the base material is high. Hard to occur. Therefore,
The jet engine combustor liner of the present invention, which has a thin film of Al-based oxide, can sufficiently maintain the heat shielding effect of TBC even when the temperature of the base material locally increases. It also has the effect of mitigating the rise. As a result, it becomes highly reliable. In this way, TBC with a thin film of Al-based oxide can be applied fully or partially to the liner, which is exposed to high temperatures in the jet engine combustor, and can be fully effective in any case. It is. In this way, the construction of TBC can be effective in increasing the output of the jet engine by increasing its temperature, as well as increasing its reliability by improving its durability. Hereinafter, the present invention will be explained in detail with reference to Examples. Example 1 Hastelloy-X (22
After degreasing and cleaning the surface, plasting was performed using a steel grid. , perform plasma spraying,
A coating layer of an alloy material consisting of 10% by weight Ni, 25% by weight Cr, 7% by weight Al, 0.6% by weight Y, 5% by weight Ta, and the balance Co was formed. Plasma spraying was carried out in Ar at a pressure of 200 Torr. In this case, the oxygen partial pressure in the atmosphere in which plasma spraying was performed was 10 ^-3 atmospheres or less, as measured by an oxygen sensor. The plasma output is 40kW. Under these conditions, the thickness of 0.01mm
Co, Ni, Cr, Al, Y alloy coating layer is formed, TBC
It was used as a bonding layer. Thereafter, a ZrO ₂ -8% by weight Y ₂ O ₃ coating layer was immediately formed on the bonding layer.
The thermal spraying conditions were a plasma output of 50kW and thermal spraying in the atmosphere. The thickness of the ZrO ₂ -8% Y ₂ O ₃ coating layer is 0.3 mm. Thereafter, a heat treatment was performed in vacuum at 1060° C. for 10 hours to perform a diffusion treatment between the bonding layer and the base material. In addition,
For comparison, a conventional method using the same material as the TBC of the present invention and a coating layer of the same thickness was performed.
Created TBC. As a conventional method, the aforementioned alloy material was thermally sprayed in the atmosphere using Ar gas, and then coated with ZrO ₂ -8% Y ₂ O ₃ in the same manner as described above. next,
In order to confirm the effects of TBC of the present invention, various tests described below were conducted. First, an oxidation test was conducted at various temperatures, and after the test, the appearance and cross-sectional structure were observed, and an adhesion test was conducted. Table 2 shows the results of appearance observation and adhesion test.

【table】

[Table] No. 1 to No. 6 in Table 2 are the results of conventional TBC, No. 7
- No. 11 are the results of the TBC of the present invention created in this example. That is, in conventional TBC, at a temperature of 1070℃ or higher (held for 100 hours), ZrO ₂ −8%Y ₂ O ₃
The coating layer peeled off and the TBC was damaged. On the other hand, TBCs No. 7 to No. 11 of the present invention have no external damage. On the other hand, the results of the TBC adhesion test after the oxidation test also showed that the TBC was not damaged in Nos. 1 to 6.
The adhesion strength of conventional TBC is 2~5Kg/ ^mm2 ,
The adhesion strength decreased as the oxidation test temperature increased. Also, the broken part in the adhesion test is the bonding layer.
This is _the boundary with _ZrO2-8 % _Y2O3 . On the other hand, No.7
~ In the TBC of the present invention shown in No. 11, no decrease in the adhesion of TBC was observed under any oxidation test conditions, and the adhesion test method using an adhesive (adhesive strength of 7 Kg/mm ² ) The value exceeded the limit value of 7Kg/ ^mm2 . Therefore, all the broken parts after the test are adhesive parts. Next, a thermal cycle test was conducted using the test piece after the above oxidation test. The test conditions were 750°C, held for 15 minutes, and held in water at 20-25°C for 15 seconds. Table 3 shows the results.

〔Effect of the invention〕

As explained above, according to the present invention, progress of oxidative corrosion of the bonding layer can be prevented, so that the bonding strength of the ceramic coating layer can be stably maintained over a long period of time.

[Brief explanation of drawings]

Fig. 1 is a photograph of the cross-sectional metallographic structure of TBC according to the present invention, Fig. 2 is a schematic diagram of a jet engine combustor to which TBC is applied, Fig. 3 is a perspective view of the outer liner, and Fig. 4 is the inner side. The perspective view of the liner, FIGS. 5 and 6, are photographs of the metallographic structure of a cross section of conventional TBC after high temperature oxidation. 5...Combustor, 6...Outer liner, 7...Inner liner.

Claims (1)

[Claims] 1. A combustor having an outer liner and an inner liner, and having a structure in which fuel combustion gas flows in the space between the two,
In a jet engine combustor in which the two liners are made of an alloy containing at least one of Ni, Co, and Fe as a main component, the opposing surfaces of the two liners contain one of Ni and Co as a main component. It has a bonding layer of an alloy containing Cr and Al and has better high-temperature oxidation resistance and high-temperature corrosion resistance than the base material, and has a coating layer made of ceramic mainly composed of ZrO ₂ on the bonding layer,
Al is placed at the boundary between the bonding layer and the ceramic coating layer.
1. A ceramic-coated jet engine combustor characterized by having an oxide layer containing as a main component. 2. A ceramic coating layer according to claim 1, characterized in that the material constituting the ceramic coating layer is mainly composed of ZrO ₂ and contains one or more of CaO, MgO, and Y ₂ O ₃ . engine combustor. 3 In claim 1, the material constituting the bonding layer is either Co or Ni.
The main components are 10 to 30% by weight of Cr and 5% by weight of Al.
Contains ~30% by weight, plus 1 of Hf, Ta, Y, Si, and Zr
1. A ceramic-coated jet engine combustor, characterized in that it is made of an alloy containing 0.1 to 5% by weight of at least one of the following: 4. The ceramic-coated jet engine combustor according to claim 1, wherein the oxide layer containing Al as a main component has a thickness of 0.1 μm to 20 μm. 5. A ceramic-coated jet engine combustor according to claim 4, wherein the bonding layer has a thickness of 0.03 mm to 0.5 mm, and the ceramic coating layer has a thickness of 0.05 mm to 0.8 mm. . 6. A jet engine combustor having an outer liner and an inner liner made of an alloy containing at least one of Ni, Co, and Fe as a main component, and having a structure in which fuel combustion gas flows through the space between the two liners. A step of forming a bonding layer of an alloy containing Ni or Co as a main component and Cr and Al, which has superior high-temperature oxidation resistance and high-temperature corrosion resistance than the liner base material, on the opposing surface, and ZrO ₂ on the surface of the bonding layer. A ceramic coating film characterized by comprising a step of forming a coating layer made of ceramic as a main component, and a heat treatment step of forming an oxide layer containing Al as a main component at the boundary between the bonding layer and the ceramic coating layer. Method for manufacturing an engine combustor. 7. The method of manufacturing a ceramic-coated jet engine combustor according to claim 6, characterized in that the bonding layer is formed by plasma spraying in an atmosphere with an oxygen content of 10 ^-3 atmospheres or less. 8. The ceramic according to claim 6, wherein the step of forming the oxide layer includes a step of heat-treating in the air at a temperature range of 600° C. to 1200° C. for 1 hour to 200 hours. A method of manufacturing a coated jet engine combustor. 9. The ceramic coated jet according to claim 6, wherein the bonding layer and the ceramic coating layer are formed by thermal spraying so as to face the downstream side of the combustor with respect to the axis of the combustor. A method of manufacturing an engine combustor.