A method for producing a thermal barrier coating alpha-aluminum oxide thermally grown oxide

Abstract

The application provides a preparation method of a thermal barrier coating alpha-Al2O3 thermal growth oxide, and belongs to the technical field of surface engineering. The preparation method comprises the following steps: preparing an MCrAlY bonding layer on the surface of a sample; cleaning the surface of the MCrAlY bonding layer; heating the MCrAlY bonding layer to a first preset temperature at a heating rate of 50-80 DEG C / s, and performing first heating treatment on the MCrAlY bonding layer, so that an alpha-Al2O3-based TGO film with a first thickness is generated on the surface of the MCrAlY bonding layer; cooling to a second preset temperature, and performing second heating treatment on the MCrAlY bonding layer, so that the alpha-Al2O3-based TGO film on the surface of the MCrAlY bonding layer continues to grow to a second thickness. The method adopts rapid heating and segmented heat treatment technology, can be used for producing and preparing the thermal barrier coating with the alpha-Al2O3 thermal growth oxide in an atmospheric environment, and has the advantages of simple process, low implementation difficulty, low production cost, reduced thermal growth stress, effectively prevented premature failure of the coating, and satisfaction of the pre-oxidation technical requirements of the thermal barrier coating of a turbine blade.

Description

Technical Field

[0001] This invention belongs to the field of surface engineering technology, specifically relating to a method for preparing thermally grown oxides of thermal barrier coating α-Al2O3. Background Technology

[0002] Gas turbines are crucial equipment for electric power and aviation propulsion, with their core hot-end components operating in environments exceeding 1300°C. Individual metal blade materials cannot withstand long-term operation at these temperatures, necessitating thermal barrier coatings (TGOs) for protection. The TGO system is a multi-layered structure primarily composed of a high-temperature alloy substrate (high-temperature blades), a bonding layer, a ceramic insulating coating, and thermally grown oxides (TGOs) formed at the interface between the bonding layer and the ceramic coating. These TGOs are generated during heat treatment or high-temperature operation. Elements such as Al, Cr, and Ni in the bonding layer diffuse to the bonding layer surface at high temperatures; simultaneously, because the YSZ coating is an oxygen ion conductor at high temperatures, oxygen diffuses through vacancies or voids in the coating to the interface and combines with Al, Cr, and Ni to form oxides.

[0003] In industrial production, after the coating of gas turbine blades is prepared, heat treatment is required. This serves two purposes: firstly, it promotes the diffusion of elements in the thermally sprayed binder layer, ensuring element supply and coating density during TGO growth; secondly, it pre-generates a layer of TGO with a low growth rate, uniformity, and continuity, thereby protecting the binder layer and reducing its oxidation rate. The composition of thermally grown oxides (TGOs) is typically Al₂O₃, NiO, Cr₂O₃, and AB₂O₄ (A = Ni, Co; B = Al, Cr) type spinel. Among these, α-Al₂O₃ is a type of TGO with advantages such as high bonding strength with the binder layer and ceramic coating, and strong oxidation resistance. Uniform and continuous α-Al₂O₃ thickness is ideal for thermal growth. However, under industrial production or laboratory conditions, TGO is usually not a single α-Al₂O₃ oxide, but rather a combination of the aforementioned oxides. In laboratories or industries, high vacuum or inert gas environments are typically used to reduce the oxygen partial pressure in the heat treatment space where the coating is located, thereby inhibiting or reducing the generation of non-Al2O3-based TGO. However, it is usually difficult to achieve the required vacuum level in an inert gas environment, resulting in the metal oxide particles still containing components such as nickel oxide, chromium oxide, and cobalt oxide. Furthermore, when preparing thermal barrier coatings using high vacuum furnaces, the required production conditions are demanding, the preparation time is long, and the production cost is high, which is not conducive to industrial applications. Summary of the Invention

[0004] The present invention aims to at least solve the technical problems existing in the prior art, such as high production conditions, high cost, long time consumption, and complex composition of pre-produced TGO, and provides a method for preparing a thermal barrier coating with α-Al2O3-based TGO film in an atmospheric environment.

[0005] This invention provides a method for preparing thermally grown α-Al₂O₃ oxide with a thermal barrier coating, the method comprising:

[0006] An MCrAlY bonding layer was prepared on the sample surface;

[0007] The surface of the MCrAlY adhesive layer is cleaned;

[0008] The MCrAlY adhesive layer is heated to a first preset temperature at a heating rate of 50-80℃ / s to perform a first heat treatment, thereby generating an α-Al2O3-based TGO film of the first thickness on the surface of the MCrAlY adhesive layer.

[0009] The temperature is lowered to a second preset temperature, and the MCrAlY adhesive layer is subjected to a second heat treatment, so that the α-Al2O3-based TGO film on the surface of the MCrAlY adhesive layer continues to grow to a second thickness.

[0010] Optionally, the first preset temperature is 1100℃~1200℃.

[0011] Optionally, the first heat treatment time is 5 min to 10 min.

[0012] Optionally, the first thickness is 0.4 to 0.8 μm.

[0013] Optionally, the second preset temperature is 850℃~1050℃.

[0014] Optionally, the second heat treatment may last for 20 to 35 minutes.

[0015] Optionally, the second thickness is 1.0 μm to 2 μm.

[0016] Optionally, the cleaned MCrAlY adhesive layer may be subjected to a first heat treatment and a second heat treatment using either flame heating or induction heating.

[0017] This invention provides a method for preparing a thermal barrier coating α-Al₂O₃ thermally grown oxide. The method includes: preparing an MCrAlY binder layer on the surface of a sample; cleaning the surface of the MCrAlY binder layer; heating the cleaned MCrAlY binder layer to a first preset temperature at a heating rate of 50–80 °C / s for a first heat treatment, thereby generating an α-Al₂O₃-based TGO film of a first thickness on the surface of the MCrAlY binder layer; cooling the surface to a second preset temperature for a second heat treatment, thereby growing the α-Al₂O₃-based TGO film on the surface of the MCrAlY binder layer to a second thickness. The method of this invention employs rapid heating and segmented heat treatment technology, enabling the preparation of an α-Al₂O₃-based TGO film thermal barrier coating in an atmospheric environment. The process is simple, easy to implement, and has low production costs. Simultaneously, it reduces thermal growth stress, effectively preventing premature coating failure and meeting the pre-oxidation technology requirements for thermal barrier coatings on gas turbine blades. Attached Figure Description

[0018] Figure 1 This is a flowchart illustrating the preparation method of α-Al2O3-based TGO film in the thermal barrier coating according to an embodiment of the present invention.

[0019] Figure 2 This is a microstructure diagram of the α-Al2O3-based TGO film after the first heating in Example 1 of the present invention;

[0020] Figure 3 This is a microstructure diagram of the α-Al2O3-based TGO film after two heating cycles in Example 1 of the present invention. Detailed Implementation

[0021] To enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only for explaining the present invention and are only some, not all, embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the protection scope of the present invention.

[0022] like Figure 1 As shown, the present invention provides a method S100 for preparing thermally grown α-Al2O3 thermal barrier coatings, specifically including the following steps S110 to S140:

[0023] S110. Prepare an MCrAlY adhesive layer on the sample surface.

[0024] It should be noted that the samples targeted in this embodiment are mainly gas turbine blades or other nickel-based high-temperature alloy sheets, and no specific limitations are made.

[0025] It should be further noted that this embodiment does not specifically limit the method for preparing the MCrAlY adhesive layer on the sample surface, such as thermal spraying or cold spraying techniques.

[0026] It should be noted that this embodiment does not specifically limit the material and thickness of the MCrAlY adhesive layer prepared on the sample surface. For example, M in the MCrAlY adhesive layer can be Co, Ni, or a combination of both. Preferably, it is a NiCoCrAlTaY adhesive layer. Furthermore, the thickness of the MCrAlY adhesive layer can be 0.1-0.5 mm, such as 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, or 0.5 mm.

[0027] S120. Clean the surface of the MCrAlY adhesive layer.

[0028] Specifically, a high-pressure airflow is used to blow away the surface of the adhesive layer to remove poorly bonded particles or dust, so as to avoid the inability to form an α-Al2O3-based TGO film during the heating process due to weak particle bonding and insufficient Al replenishment in the particles.

[0029] In some preferred embodiments, the pressure of the high-pressure gas flow is 0.5-1.0 MPa, for example, 0.5 MPa, 0.7 MPa, 0.8 MPa, 1.0 MPa, etc.

[0030] S130. The temperature is increased to the first preset temperature at a heating rate of 50℃ / s to 80℃ / s to perform the first heat treatment on the cleaned MCrAlY adhesive layer, thereby generating an α-Al2O3-based TGO film of the first thickness on the surface of the MCrAlY adhesive layer.

[0031] Specifically, the surface of the cleaned MCrAlY adhesive layer is subjected to a first rapid heating treatment using flame heating or induction heating methods. The temperature is increased to 1100℃~1200℃ at a heating rate of 50℃ / s~80℃ / s and heated for 5min~10min to generate a first α-Al2O3-based TGO film with a thickness of 0.4μm~0.8μm on the surface of the MCrAlY adhesive layer.

[0032] In some preferred embodiments, the first thickness may preferably be 0.4 μm, 0.6 μm, or 0.8 μm.

[0033] As a further preferred option, the first preset temperature can be 1100℃, 1150℃, or 1200℃, the heating rate of the first heating treatment can be 50℃ / s, 60℃ / s, 70℃ / s, or 80℃ / s, and the time of the first heating treatment can be 5min, 6min, 7min, 8min, 9min, or 10min.

[0034] It should be noted that when using the flame heating method to heat the MCrAlY bonding layer, the flame is used to heat the back of the alloy, and the temperature of the front is detected by an infrared thermometer. By adjusting the gas flow rate and power of the flame gun, the heating rate and the first preset temperature are made to reach the preset value. After heat preservation treatment, an α-Al2O3-based TGO film with a first thickness is formed on the MCrAlY bonding layer.

[0035] It should be further noted that when using induction heating to heat the MCrAlY adhesive layer, a high-frequency induction heating coil can be wound around the sample and heated as a whole. After reaching the preset heating rate and the first preset temperature, the sample is then kept warm to form an α-Al2O3-based TGO film with a first thickness on the MCrAlY adhesive layer.

[0036] In this embodiment, a uniform and continuous α-Al2O3-based TGO film can be rapidly formed on the surface of the adhesive layer by using a rapid heating method. The heat treatment time is short, requiring only 5-10 minutes.

[0037] S140. Cool down to the second preset temperature and perform a second heat treatment on the MCrAlY adhesive layer to allow the α-Al2O3-based TGO film on the surface of the MCrAlY adhesive layer to continue growing to the second thickness.

[0038] Specifically, after the first heat treatment of the MCrAlY binder layer, a cooling treatment is required. The MCrAlY binder layer is then heated again at a relatively low temperature to allow the α-Al₂O₃-based TGO film to continue growing and increase in thickness. After two heat treatments, a final α-Al₂O₃-based TGO film with a thickness of 1.0–2 μm is obtained. In other words, after the first heat treatment, an α-Al₂O₃-based TGO film of a certain thickness is formed on the surface of the MCrAlY binder layer. Then, after cooling to a certain temperature, a heat treatment is performed to promote oxide growth and diffusion of the binder layer, further forming the α-Al₂O₃-based TGO film and increasing the final α-Al₂O₃-based TGO film thickness. That is, the second thickness includes both the thickness of the α-Al₂O₃-based TGO film formed by the second heat treatment and the first thickness formed by the first heat treatment.

[0039] In some preferred embodiments, the second thickness obtained after two heat treatments is 1.0-2.0 μm, for example, 1.0 μm, 1.2 μm, 1.5 μm, 1.8 μm, 2.0 μm, etc.

[0040] In some other preferred embodiments, the second preset temperature is 850°C to 1050°C, and the second heating treatment time is 20 min to 35 min.

[0041] As a further preferred option, the second preset temperature can preferably be 850℃, 950℃, 1000℃, or 1050℃, the cooling rate can preferably be 10℃ / s, 15℃ / s, or 20℃ / s, and the second heating treatment time can preferably be 20min, 25min, 30min, or 35min.

[0042] It should be further noted that after the MCrAlY adhesive layer is first heated using the flame heating method, the flame distance is adjusted and the temperature is lowered to a second preset temperature according to a preset cooling rate. After heat preservation treatment, the thickness of the MCrAlY adhesive layer is further increased.

[0043] It should be noted that after the MCrAlY adhesive layer is heated for the first time using induction heating, the heating power is adjusted and the temperature is lowered to the second preset temperature according to the preset cooling rate. After heat preservation treatment, the thickness of the MCrAlY adhesive layer is further increased.

[0044] In this embodiment, by adopting a rapid and high-speed heating method, based on the different Gibbs free energies and required oxygen partial pressures of metal elements such as Al, Cr, and Ni during the oxidation process, as shown in Table 1, the Gibbs free energy of Al2O3 formation is much lower than the Gibbs free energy and oxygen partial pressure required for the formation of oxides such as NiO, Cr2O3, and AB2O4. In other words, the formation conditions of aluminum oxide are the least demanding, and among the above oxides, Al2O3 will be preferentially produced over other oxides. Based on this, this embodiment innovatively uses a short-time rapid heating method to rapidly and preferentially oxidize Al. Before oxides such as Cr, Co, and Ni reach the formation conditions, a dense and continuous α-Al2O3-based TGO film has been established on the coating surface. At this point, the high-temperature heating is stopped, and the heating temperature is lowered to further reduce the oxidation activity of other elements. At the same time, since a dense and continuous α-Al2O3-based TGO film has been formed on the coating surface, the oxygen partial pressure between the adhesive layer metal and the TGO film is reduced, achieving the same effect as high-vacuum heat treatment. This effectively suppresses the formation of other non-α-Al2O3-based TGO films, thereby achieving the formation of only an α-Al2O3-based TGO film on the adhesive layer.

[0045] Table 1 Gibbs free energy and minimum oxygen partial pressure required for the formation of different oxides.

[0046]

[0047]

[0048] In this embodiment, the thermal barrier coating formed by the above method includes an MCrAlY binder layer and an α-Al₂O₃-based TGO film stacked on the sample surface. The MCrAlY binder layer is preferably a NiCoCrAlTaY binder layer, with a thickness of 0.1-0.5 mm, and the α-Al₂O₃-based TGO film has a thickness of 1.0-2 μm. This thermally grown oxide has the advantages of high bonding strength with the binder layer and strong oxidation resistance.

[0049] Of course, it should be understood that the thermal barrier coating may also include a thermal insulation coating, that is, a thermal insulation coating formed on the surface of the α-Al2O3-based TGO film, such as a YSZ ceramic coating.

[0050] It should be noted that since the α-Al2O3-based TGO film of this embodiment is based on rapid heat treatment, the order in which the above-mentioned heat-insulating coating is formed is not specifically limited. For example, the α-Al2O3-based TGO film can be formed on the surface of the adhesive layer by heat treatment first, and then the heat-insulating coating can be prepared on the α-Al2O3-based TGO film. Alternatively, the heat-insulating coating can be prepared on the adhesive layer first, and then the α-Al2O3-based TGO film can be formed between the adhesive layer and the heat-insulating coating by heat treatment.

[0051] In this embodiment, by employing a rapid heat treatment method, an α-Al2O3-based TGO film can be generated on the surface of the adhesive layer in an atmospheric environment. This eliminates the need for equipment such as extremely high vacuum or high-purity inert atmosphere furnaces, resulting in low production requirements and short preparation time, which is beneficial for industrial applications.

[0052] The preparation method of thermally grown oxide α-Al2O3 thermal barrier coating will be further explained below with reference to specific embodiments:

[0053] Example 1

[0054] The preparation method of the thermally grown α-Al2O3 oxide thermal barrier coating in this example includes the following steps:

[0055] S1. A NiCoCrAlTaY bonding layer with a thickness of about 0.2 mm is prepared on the surface of a nickel-based high-temperature alloy disc with a diameter of 25 mm using a supersonic flame spraying process (other thermal spraying processes can also be used).

[0056] S2. After cooling, the sample surface is cleaned with 0.7MPa compressed air to remove weakly bonded metal particles or floating dust, so as to avoid the inability to form α-Al2O3-based TGO film during heating due to weak particle bonding and insufficient Al replenishment in the particles.

[0057] S3. The back of the nickel-based alloy is heated using a flame heating method, while the front is monitored using an infrared thermometer. The gas flow rate and power of the flame gun are adjusted to achieve a heating rate of 80℃ / s on the coating surface. After approximately 12 seconds, the temperature reaches 1150℃. This high temperature is maintained for 6 minutes, resulting in the formation of a first α-Al₂O₃-based TGO film with a thickness of approximately 0.51 μm on the coating surface. Figure 2 As shown, the black lines represent α-Al2O3-based TGO films.

[0058] S4. Adjust the flame distance and reduce the coating surface temperature to 850℃ within 10 seconds, maintain this temperature for 35 minutes to promote diffusion within the coating and the growth of the α-Al2O3-based TGO film. Allow the α-Al2O3-based TGO film to continue growing to 2μm, resulting in a 2μm thick α-Al2O3-based TGO film on the NiCoCrAlTaY adhesive layer. Figure 3 As shown.

[0059] S5. The thermal barrier coating can be prepared by spraying YSZ ceramic coating onto the oxidized coating surface using plasma spraying.

[0060] In this embodiment 1, a rapid heat treatment is performed before spraying the ceramic coating, and no post-heat treatment is required after the coating is sprayed.

[0061] Example 2

[0062] The preparation process is basically the same as that in Example 1, except that: after step S2, step S5 is performed first, followed by steps S3 and S4. That is, the ceramic coating is sprayed immediately after the NiCoCrAlTaY adhesive layer is prepared, and then rapid flame heat treatment is performed. Similarly, a 2μm thick α-Al2O3-based TGO film can be finally obtained on the NiCoCrAlTaY adhesive layer.

[0063] Example 3

[0064] The preparation process is basically the same as that in Example 1, except that: Example 3 is for real gas turbine blades, and high-frequency induction heating is used in steps S3 and S4. That is, a NiCoCrAlTaY bonding layer with a thickness of about 0.2 mm is prepared on the surface of the gas turbine blade, and the bonding layer is heated by high-frequency induction heating to finally obtain an α-Al2O3-based TGO film with a thickness of 2 μm. Then, a YSZ ceramic coating is sprayed on the oxidized surface by plasma spraying.

[0065] Example 4

[0066] The preparation process is basically the same as that in Example 3, except that: after step S2, step S5 is performed first, followed by S3 and S4. That is, a NiCoCrAlTaY bonding layer with a thickness of about 0.2 mm is prepared on the surface of the gas turbine blade. A ceramic coating is applied to the surface of the NiCoCrAlTaY bonding layer by plasma spraying. Then, the bonding layer is heated by high-frequency induction heating to finally obtain an α-Al2O3-based TGO film with a thickness of 2 μm.

[0067] Example 5

[0068] The preparation process is basically the same as that in Example 1, except that in step S3, the heating rate is 50℃ / s for the first time. After about 20s, the temperature reaches 1200℃, and a 2μm α-Al2O3-based TGO film can still be obtained. In the heating rate range of this Example 5, changing the heating rate has no significant effect on the final thickness of TGO.

[0069] Example 6

[0070] The preparation process is basically the same as that in Example 1, except that in step S3, the first heating rate is 30℃ / s, which yields an α-Al2O3-based TGO film with a thickness of about 0.53μm. However, the TGO also contains oxides such as Cr2O3 and NiAl2O4, which cannot achieve the purpose of this invention.

[0071] Example 7

[0072] The preparation process is basically the same as that in Example 1, except that in step S3, the heating rate for the first heating is 90°C / s. This heating rate may cause the TGO film to break and peel off, resulting in poor continuity and thickness uniformity of the TGO film, which fails to achieve the purpose of this invention.

[0073] Example 8

[0074] The preparation process is basically the same as that in Example 1, except that in step S3, the first preset temperature of the first heating treatment reaches 900°C, which is lower than the minimum first preset temperature of 1100°C required by the present invention. The obtained TGO film has an uneven structure and contains Cr2O3, NiAl2O4 and needle-like θ-Al2O3.

[0075] Example 9

[0076] The preparation process is basically the same as that in Example 1, except that in step S3, the first preset temperature of the first heating treatment reaches 1200°C, and an α-Al2O3-based TGO film with a first thickness of about 0.8 μm can be obtained.

[0077] Example 10

[0078] The preparation process is basically the same as that in Example 1, except that in step S3, the first preset temperature of the first heating treatment reaches 1300℃, the material burn-deformation, the growth kinetic energy of Cr2O3 and NiAl2O4 increases dramatically, and the TGO composition is impure.

[0079] Example 11

[0080] The preparation process is basically the same as that in Example 1, except that in step S3, the duration of the first heating treatment is less than 5 minutes, which will cause TGO to be discontinuous and have a lower thickness. In the subsequent second stage of heating, O will pass through the thinner TGO film and react with non-Al elements to produce non-α-Al2O3 oxides.

[0081] Example 12

[0082] The preparation process is basically the same as that in Example 1, except that: in step S3, the duration of the first heating treatment is >10 min. At this time, maintaining a high growth rate will cause Al depletion on the surface of the adhesive layer, and elements such as Cr and Ni will be oxidized. Oxides such as Cr2O3 and NiAl2O4 will be generated in the TGO film.

[0083] Example 13

[0084] The preparation process is basically the same as that in Example 1, except that in step S4, the second preset temperature of the second heating treatment is 1050°C, which can produce a second α-Al2O3-based TGO film with a thickness of about 2μm.

[0085] Example 14

[0086] The preparation process is basically the same as that in Example 1, except that: in step S4, the second preset temperature of the second heating treatment is 1100℃, which is greater than 1050℃. At this time, the higher TGO growth rate will cause Al depletion on the surface of the adhesive layer, and the activity of elements such as Cr and Ni will increase, which will lead to oxidation. Oxides such as Cr2O3 and NiAl2O4 will be generated in the TGO film.

[0087] Example 15

[0088] The preparation process is basically the same as that in Example 1, except that in step S4, the second preset temperature of the second heating treatment is <850°C. At this time, a densification effect cannot be formed, and the diffusion ability of Al is reduced, which cannot promote the growth of α-Al2O3-based TGO film.

[0089] Example 16

[0090] The preparation process is basically the same as that in Example 1, except that in step S4, the duration of the second heating treatment is less than 20 minutes, which will cause the final thickness of the TGO film to be low and non-α-Al2O3 oxides to be generated prematurely during the production and service life.

[0091] Example 17

[0092] The preparation process is basically the same as that in Example 1, except that in step S4, the duration of the second heating treatment is >35 min, which will cause the final thickness of the TGO film to be too large, and the coating will peel off prematurely due to thermal fatigue during the service of the thermal barrier coating.

[0093] Example 18

[0094] The preparation process is basically the same as that in Example 1, except that in step S4, the cooling rate during the process of cooling from the first heat treatment to the second preset temperature is >20℃ / s, which will cause the TGO film to peel off.

[0095] Example 19

[0096] The preparation process is basically the same as that in Example 1, except that in step S4, the cooling rate during the process of cooling from the first heat treatment to the second preset temperature is <10℃ / s, which will cause the TGO film to grow too thick and be affected by thermal fatigue during the service of the thermal barrier coating, resulting in premature peeling of the coating.

[0097] In summary, according to Examples 1-19, the optimal heating rate for the first heating treatment is 50℃ / s to 80℃ / s, the first preset temperature is 1100℃ to 1200℃, and the time is 5min to 10min. The optimal cooling rate for the second heating treatment is 10 to 20℃ / s, the second preset temperature is 850℃ to 1050℃, and the time is 20min to 35min. Under the above conditions, a thermal barrier coating consisting only of an α-Al2O3-based TGO film can be obtained.

[0098] This invention proposes a method for preparing thermally grown α-Al₂O₃ oxide thermal barrier coatings, which has the following advantages compared to existing technologies:

[0099] 1) The preparation process of the present invention is simple and the production difficulty is reduced. In order to generate an α-Al2O3-based TGO film on the surface of the adhesive layer, only a segmented rapid heating heat treatment method is required, which can be achieved in an atmospheric environment without the need for heat treatment in a true high vacuum or high purity inert atmosphere furnace.

[0100] 2) The heat treatment time of the present invention is usually <45 minutes, which greatly shortens the processing time and reduces production costs compared to the current heat treatment time, which usually takes several hours to more than ten hours.

[0101] 3) The method of the present invention can directly obtain an α-Al2O3-based TGO film with a thickness of 1.0μm to 2μm, which inhibits the generation of other non-α-Al2O3-based TGO, effectively improves the bonding strength between the adhesive layer and the ceramic coating, enhances the oxidation resistance, prevents premature failure of the coating, and meets the technical requirements for pre-oxidation of thermal barrier coatings for gas turbine blades.

[0102] It is understood that the above embodiments are merely exemplary implementations used to illustrate the principles of the present invention, and the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A method of producing a thermal barrier coating α-ΑΙ203 thermally grown oxide, characterized by, The preparation method comprises the following steps: preparing an MCrAlY bonding layer on the surface of a sample; the MCrAlY bonding layer is NiCrAlY, CoCrAlY, NiCoCrAlY or NiCoCrAlTaY; cleaning the surface of the MCrAlY bonding layer; heating the cleaned MCrAlY bonding layer to a first preset temperature at a heating rate of 50-80 ℃ / s, and performing first heating treatment on the MCrAlY bonding layer, wherein the first heating treatment is performed for 5-10 min, and an α-Al2O3-based TGO film with a first thickness is formed on the surface of the MCrAlY bonding layer; cooling the MCrAlY bonding layer to a second preset temperature at a cooling rate of 10-20 ℃ / s, and performing second heating treatment on the MCrAlY bonding layer, so that the α-Al2O3-based TGO film on the surface of the MCrAlY bonding layer continues to grow to a second thickness.

2. The method for preparing the thermal barrier coating α-Al₂O₃ thermally grown oxide according to claim 1, characterized in that, The first preset temperature is 1100-1200 ℃.

3. The method for preparing the thermal barrier coating α-Al₂O₃ thermally grown oxide according to claim 1, characterized in that, The first thickness is 0.4-0.8 μm.

4. The method of claim 1, wherein the thermal barrier coating a- Al203 thermally grown oxide is prepared by the steps of: The second preset temperature is 850-1050 ℃.

5. The method for preparing the thermal barrier coating α-Al₂O₃ thermally grown oxide according to claim 1, characterized in that, The second heating treatment is performed for 20-35 min.

6. The method of claim 1, wherein the thermal barrier coating a- Al203 thermally grown oxide is prepared by the steps of: The second thickness is 1.0-2 μm.

7. The method of producing a thermal barrier coating a-Al2O3 thermally grown oxide according to any one of claims 1 to 6, characterized in that, The first heating treatment and the second heating treatment on the cleaned MCrAlY bonding layer are performed by using a flame heating method or an induction heating method.

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