Composite thermal insulation coating containing rare earth oxide, and preparation method therefor and use thereof

Abstract

Disclosed in the present invention are a composite thermal insulation coating containing a rare earth oxide, and a preparation method therefor and the use thereof. The preparation method comprises: preparing a non-Ce rare earth metal RE, Ce and a metal M into an RE-Ce-M alloy target according to a preset stoichiometric ratio; and sputtering the RE-Ce-M alloy target material onto the surface of a ceramic transition layer on a high-temperature alloy substrate, and treating same in a certain oxidizing atmosphere, so as to form a composite thermal insulation coating containing a rare earth oxide on the high-temperature alloy substrate, wherein the composition of the composite thermal insulation coating containing a rare earth oxide is (RE)2-x(Ce1-yMy)2+xO7±z. The present invention effectively avoids the problem of component deviation caused by the difference in properties such as the saturated vapor pressure of a certain component during thermal spraying and plasma physical vapor deposition, thereby ensuring that the obtained coating conforms to the stoichiometric ratio, and improving the consistency and stability of the coating.

Description

A composite thermal insulation coating containing rare earth oxides, its preparation method and application Cross-referencing

[0001] This application is based on and claims priority to Chinese patent applications No. 202411861044.3, filed on December 17, 2024, and No. 202411673363.1, filed on November 21, 2024, the entire contents of which are incorporated herein by reference.

[0002] Technical Field

[0003] This invention belongs to the field of rare earth oxide composite heat insulation coating preparation, specifically relating to a rare earth oxide-containing composite heat insulation coating, its preparation method and application. Background Technology

[0004] Each molecular unit of the A2B2O7 type compound contains one oxygen vacancy, resulting in a high oxygen vacancy concentration in its crystal lattice. Furthermore, the A and B sites can be replaced by various other cations with similar atomic radii. Combined with its complex cellular structure and the presence of large rare-earth atoms within the cell, this material exhibits high melting point, low thermal conductivity, and high chemical stability. Consequently, it has been extensively studied in the field of thermal barrier coatings and is considered one of the most promising new thermal barrier coating ceramic materials. Maloney of United Technologies Corporation filed the first patent for this type of novel thermal barrier coating ceramic material in 1996, and Pratt & Whitney has successfully tested it in military aero engines. There are two methods for preparing thermal barrier ceramic coatings: atmospheric plasma spraying (APS) and electron beam physical vapor deposition (EB-PVD). In APS, ceramic powder is granulated and then melted and accelerated by a high-temperature plasma flame. The molten particles impact and spread on the metal substrate to form a coating. EB-PVD technology uses a high-energy electron beam to bombard, melt, and evaporate the target material. The evaporated target atoms or molecules are deposited on the workpiece to form a thermal barrier coating with a columnar crystal structure.

[0005] It is particularly important to emphasize that, regardless of whether APS or EB-PVD processes are used to prepare thermal barrier coatings of A2B2O7 type compounds (such as rare earth zirconate compounds), the final composition of the coating often differs from that of the powder or target material. This is because, during the APS or EB-PVD process, the differences in properties such as the high saturated vapor pressure of each element can cause changes in the coating composition, resulting in a deviation between the actual composition of the coating and the designed composition, or even phase separation, which reduces the performance of the thermal barrier coating. Summary of the Invention

[0006] (a) Purpose of the invention

[0007] The purpose of this invention is to provide a composite heat-insulating coating containing rare earth oxides, its preparation method, and its application. The method first prepares a multi-component alloy target material according to the designed coating composition, sputters it onto the surface of a ceramic transition layer of a high-temperature alloy under a certain temperature and atmosphere, and then performs oxidation treatment. This effectively avoids the coating composition deviation problem caused by the difference in properties such as the supersaturated vapor pressure of a certain component during thermal spraying and plasma physical vapor deposition, ensuring that the obtained coating meets the stoichiometric ratio, thereby improving the performance of the coating.

[0008] (II) Technical Solution

[0009] To ensure the prepared coating composition conforms to the designed stoichiometric ratio, precise control of the compositional consistency during the target sputtering process is crucial, as it determines the final coating performance and service life. Service life is key to its successful application in aerospace products. Therefore, a first aspect of this invention provides a method for preparing a composite thermal insulation coating containing rare earth oxides, comprising preparing the composite thermal insulation coating containing rare earth oxides on a high-temperature alloy substrate, wherein the composite thermal insulation coating composition is (RE). 2-x (Ce 1-y M y ) 2+x O 7±z RE is at least one rare earth element other than Ce, M is at least one metallic element other than rare earth elements, 0≤x≤0.5, 0≤y≤1, 0≤z≤0.5, and the preparation method of the composite heat-insulating coating includes the following steps:

[0010] S1, according to the preset stoichiometric ratio, non-Ce rare earth metal RE, metal Ce and metal M are prepared into RE-Ce-M alloy target;

[0011] S2, a metal bonding layer is first prepared on the high-temperature alloy substrate, and then a ceramic transition layer is prepared on the metal bonding layer;

[0012] S3, the RE-Ce-M alloy target is sputtered onto the surface of the ceramic transition layer, and an oxidizing atmosphere is introduced to form a composite heat-insulating coating containing rare earth oxides on the high-temperature alloy substrate.

[0013] Further, RE is at least one of La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Sc, and Y, and M is at least one of Zr, Ti, Ge, Sn, Th, Hf, Si, Al, Nb, Ta, Sr, Mg, and Ca.

[0014] Furthermore, the oxidizing atmosphere in step S3 includes oxygen, a mixture of oxygen and air, a mixture of oxygen and nitrogen, and a mixture of oxygen and inert gases.

[0015] Furthermore, in step S3, the sputtering reaction temperature is 100℃~800℃, and the sputtering reaction time is 2~12 h.

[0016] Furthermore, the preparation method further includes S4, which involves heat-treating the obtained composite heat-insulating coating containing rare earth oxides.

[0017] Furthermore, the heat treatment temperature is 400℃~1000℃, and the holding time is 2 h~10 h.

[0018] Furthermore, the heat treatment process is carried out in an oxidizing atmosphere, which is the same as in step S3.

[0019] Furthermore, the thickness of the composite heat insulation coating is 20μm to 400μm.

[0020] Furthermore, the composition of the metal bonding layer includes PtAl, NiCoCrAlY, NiCrAlY, NiCoCrAlYHf and NiCoCrAlYSi, and the thickness of the metal bonding layer is 20μm to 200μm.

[0021] Furthermore, the main component of the ceramic transition layer includes rare earth-containing zirconium-based oxide, and the thickness of the ceramic transition layer is 20 μm to 400 μm.

[0022] A second aspect of the present invention provides a composite thermal insulation coating containing rare earth oxides, wherein the composite thermal insulation coating containing rare earth oxides is obtained by any of the preparation methods for the composite thermal insulation coating containing rare earth oxides described above, and the composite thermal insulation coating containing rare earth oxides is distributed on a high-temperature alloy substrate, and its composition is (RE). 2-x (Ce 1-y M y ) 2+x O 7±z RE is at least one rare earth element other than Ce, M is at least one metallic element other than rare earth elements, 0≤x≤0.5, 0≤y≤1, 0≤z≤0.5.

[0023] Furthermore, a metal bonding layer and a ceramic transition layer distributed from bottom to top are also included between the high-temperature alloy substrate and the composite heat insulation coating, and the composite heat insulation coating is deposited on the surface of the ceramic transition layer.

[0024] Further, RE is at least one of La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Sc, and Y, and M is at least one of Zr, Ti, Ge, Sn, Th, Hf, Si, Al, Nb, Ta, Sr, Mg, and Ca.

[0025] A third aspect of the present invention provides an application of a rare earth oxide-containing composite thermal insulation coating in the field of thermal protection of high-temperature alloys and equipment, wherein the composite thermal insulation coating is obtained by any of the preparation methods of the rare earth oxide-containing composite thermal insulation coating described above.

[0026] (III) Beneficial Effects

[0027] The above-mentioned technical solution of the present invention has the following beneficial technical effects: The present invention provides a composite heat-insulating coating containing rare earth oxides, its preparation method and application. In the preparation method, an oxide coating with a specific composition is prepared using an alloy target. The process employs physical vapor deposition methods such as magnetron sputtering and oxidation is carried out in an oxidizing atmosphere. The main component of the composite heat-insulating coating containing rare earth oxides obtained is (RE). 2-x (Ce 1-y M y ) 2+x O 7±z The resulting thermal insulation coating exhibits good compositional consistency and excellent performance. The specific preparation process is as follows: First, non-Ce rare earth metals (RE), Ce, and M are prepared into an RE-Ce-M alloy target according to a preset stoichiometric ratio. Then, a metal bonding layer is first prepared on the high-temperature alloy substrate, followed by a ceramic transition layer. Finally, the RE-Ce-M alloy target is sputtered onto the surface of the ceramic transition layer, and an oxidizing atmosphere is introduced to form a composite thermal insulation coating containing rare earth oxides on the high-temperature alloy substrate. This invention effectively avoids compositional deviations caused by differences in properties such as supersaturated vapor pressure of each component during thermal spraying and plasma physical vapor deposition by precisely controlling the composition of the multi-component alloy target and the flow rate of the oxidizing atmosphere during the oxidation process. This results in a thermal insulation coating with no elemental loss that conforms to the composition design, ensuring that the obtained coating conforms to the stoichiometric ratio and thus improving the coating's consistency and stability. Attached Figure Description

[0028] Figure 1 is a schematic diagram of the distribution structure of the rare earth oxide-containing composite heat-insulating coating of the present invention on a high-temperature alloy substrate. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments and the accompanying drawings. It should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0030] I. One aspect of the present invention provides a method for preparing a composite heat-insulating coating containing rare earth oxides, comprising preparing a composite heat-insulating coating containing rare earth oxides on a high-temperature alloy substrate, wherein the composite heat-insulating coating is composed of (RE). 2-x (Ce 1-y M y ) 2+x O 7±z RE is at least one rare earth element other than Ce, M is at least one metallic element other than rare earth elements, 0≤x≤0.5, 0≤y≤1, 0≤z≤0.5, and the preparation method of the composite heat-insulating coating includes the following steps:

[0031] S1, non-Ce rare earth metal RE, metal Ce, and metal M are prepared into a RE-Ce-M alloy target according to a preset stoichiometric ratio. In this step, the RE-Ce-M alloy target is prepared by casting or powder metallurgy. The preset stoichiometric ratio refers to the ratio of (RE) to... 2-x (Ce 1-y M y ) 2+x The corresponding proportions of the parts; wherein the RE includes at least one of La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Sc, and Y, and the M is at least one of Zr, Ti, Ge, Sn, Th, Hf, Si, Al, Nb, Ta, Sr, Mg, and Ca. Preferably, the M is at least one of Zr, Hf, Ge, Sn, Ta, and Ti.

[0032] S2, a metal bonding layer is first prepared on the high-temperature alloy substrate, and then a ceramic transition layer is prepared on the metal bonding layer;

[0033] S3, the RE-Ce-M alloy target is sputtered onto the surface of the ceramic transition layer, and an oxidizing atmosphere is introduced to form a composite heat-insulating coating containing rare earth oxides on the high-temperature alloy substrate. In this step, the RE-Ce-M alloy target is first pre-sputtered using physical vapor deposition (PVD) for 5–20 min. Argon gas is introduced before pre-sputtering at a flow rate of 20–30 mL / min to remove oxides and other impurities from the target surface, ensuring sputtering stability and coating quality. The pre-sputtered RE-Ce-M alloy target is then sputtered onto the ceramic transition layer surface of the high-temperature alloy substrate. The PVD technique includes at least one of vacuum deposition, vacuum sputtering deposition, magnetron sputtering deposition, arc ion plating, ion beam enhanced deposition, electrical discharge deposition, and multilayer jet deposition. During the sputtering process, an oxidizing atmosphere is introduced at a certain temperature to obtain a composite heat-insulating coating containing rare earth oxides. In this process, the oxidizing atmosphere flow rate is controlled at 1–100 mL / min, preferably 5–50 mL / min, and the sputtering reaction time is controlled at 2–12 h, preferably 3–8 h. h, the sputtering reaction temperature is 100-800℃, preferably 200-500℃, and the oxidizing atmosphere includes oxygen, a mixture of oxygen and air, a mixture of oxygen and nitrogen, and a mixture of oxygen and inert gases. The thickness of the composite heat-insulating coating is 20μm-400μm, preferably 100μm-200μm.

[0034] Furthermore, the method further includes S4, which involves heat-treating the obtained rare earth oxide-containing composite heat-insulating coating. This step specifically includes: placing the rare earth composite oxide coating in a furnace for oxidation heat treatment while simultaneously introducing an oxidizing atmosphere; the heat treatment temperature (furnace temperature) is 400–1000°C, preferably 650–850°C; the flow rate of the oxidizing atmosphere is 5–100 mL / min, preferably 10–70 mL / min; the holding time is 2–10 h, preferably 4–7 h; and the oxidizing atmosphere includes oxygen, a mixture of oxygen and air, a mixture of oxygen and nitrogen, and a mixture of oxygen and inert gases.

[0035] Figure 1 is a schematic diagram of the distribution structure of the rare-earth oxide-containing composite thermal insulation coating on a high-temperature alloy substrate according to the present invention. From bottom to top, the structure consists of a high-temperature alloy substrate, a metal bonding layer, a ceramic transition layer, and a composite thermal insulation coating (a rare-earth oxide-containing composite thermal insulation coating). The composite thermal insulation coating is deposited on the surface of the ceramic transition layer for thermal insulation protection. The high-temperature alloy substrate is a nickel-based high-temperature alloy, which can be a cast high-temperature alloy, a directionally solidified high-temperature alloy, or a single-crystal high-temperature alloy. The metal bonding layer comprises PtAl, NiCoCrAlY, NiCrAlY, NiCoCrAlYHf, and NiCoCrAlYSi, and its thickness is 20–200 μm. The main component of the ceramic transition layer is a rare-earth-containing zirconium-based oxide, and its thickness is 20–400 μm. Among them, 6~8%YSZ is used as the ceramic structure transition layer. 6~8%YSZ refers to 6~8% by mass of yttrium oxide partially stabilized zirconia ceramic material. For example, the ceramic structure transition layer contains 8%Y2O3 and 92%ZrO2.

[0036] A second aspect of the present invention provides a composite thermal insulation coating containing rare earth oxides, wherein the composite thermal insulation coating containing rare earth oxides is obtained by any of the preparation methods for the composite thermal insulation coating containing rare earth oxides described above, and the composite thermal insulation coating containing rare earth oxides is distributed on a high-temperature alloy substrate, and its composition is (RE). 2-x (Ce 1-y M y ) 2+x O 7±z RE is at least one rare earth element other than Ce, and M is at least one metallic element other than rare earth elements, with 0≤x≤0.5, 0≤y≤1, and 0≤z≤0.5. Preferably, RE is at least one of La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Sc, and Y, and M is at least one of Zr, Ti, Ge, Sn, Th, Hf, Si, Al, Nb, Ta, Sr, Mg, and Ca. The thickness of the composite thermal insulation coating is 20μm to 400μm, preferably 100μm to 200μm. Between the high-temperature alloy substrate and the composite thermal insulation coating, there is also a bottom-up distributed metal bonding layer and a ceramic transition layer, with the composite thermal insulation coating deposited on the surface of the ceramic transition layer.

[0037] Furthermore, a third aspect of the present invention provides the application of a rare-earth oxide-containing composite thermal insulation coating in the field of thermal protection for high-temperature alloys and equipment. The composite thermal insulation coating is obtained by any of the methods described above for preparing a rare-earth oxide-containing composite thermal insulation coating. The rare-earth oxide-containing composite thermal insulation coating prepared by the present invention can be used as a thermal protection ceramic coating for high-temperature alloys, and preferably, is applied to the field of thermal insulation coatings for automotive, aircraft, and gas turbine engine components.

[0038] II. Detailed Implementation

[0039] Example 1

[0040] In this embodiment, Gd, Yb, and Zr were used as raw materials, and a vacuum induction melting and rapid cooling technology was employed to produce Gd with uniform composition. 1.8 Yb 0.2 Zr2 alloy target. In this embodiment, the high-temperature alloy substrate is a nickel-chromium-iron-based GH3536 high-temperature alloy, with a PtAl alloy as the metal binder layer and an 8% Y2O3 partially stabilized ZrO2 ceramic transition layer. First, a metal binder layer is prepared on the high-temperature alloy substrate, then a ceramic transition layer is prepared on the metal binder layer. Next, the prepared rare-earth alloy target is sputtered onto the surface of the ceramic transition layer of the high-temperature alloy substrate using a magnetron sputtering device, while simultaneously introducing an oxygen atmosphere to obtain (Gd... 0.9 Yb 0.1 )2Zr2O7 composite thermal insulation coating. The specific steps are as follows: First, bombard and clean the surface of the alloy target for 5-10 minutes (pre-sputtering of the alloy target). Before pre-sputtering, argon gas is introduced at a flow rate of 20-30 mL / min. Then, the pre-sputtered alloy target is sputtered onto the surface of the ceramic transition layer of the alloy substrate, while oxygen is introduced at a flow rate of 30 mL / min. The sputtering environment temperature is controlled at 500℃, and sputtering is carried out for 8 hours to obtain (Gd 0.9 Yb 0.1 The composite heat insulation coating of Zr2O7 was then placed in a furnace at 700℃ and oxygen was introduced at a rate of 70 mL / min for further oxidation heat treatment. The temperature was maintained for 7 h to further promote the uniform diffusion of each component. The thickness of the composite heat insulation coating was about 200 μm. The test results of each embodiment of the present invention are shown in Table 1.

[0041] Example 2

[0042] In this embodiment, La₂Zr was prepared using La, Zr, and Ta as raw materials and vacuum induction melting and rapid solidification technology. 1.4 Ta 0.6Alloy target material. The high-temperature alloy substrate is made of nickel-chromium-iron-based GH3536 high-temperature alloy, with NiCrAlY alloy as the metal binder layer and 8% Y2O3 partially stabilized ZrO2 as the ceramic transition layer. First, the metal binder layer is prepared on the high-temperature alloy substrate, and then the ceramic transition layer is prepared on the metal binder layer. Then, the prepared rare-earth alloy target material is sputtered onto the surface of the ceramic transition layer of the alloy substrate using a magnetron sputtering device, and an oxidizing atmosphere is introduced to obtain a composite heat-insulating coating. The specific steps are: first, the surface of the alloy target material is bombarded and cleaned for 5-10 minutes (pre-sputtering of the alloy target material). Before pre-sputtering, argon gas is introduced at a flow rate of 20-30 mL / min. Then, the pre-sputtered alloy target material is sputtered onto the surface of the ceramic transition layer of the alloy substrate, while oxygen is introduced at a flow rate of 30 mL / min. The sputtering environment temperature is controlled at 500℃, and sputtering is carried out for 8 hours to obtain La2(ZrO2)2. 0.7 Ta 0.3 The composite heat insulation coating is then placed in an 850℃ furnace and further oxidized by introducing oxygen at a rate of 70 mL / min, while maintaining the temperature for 5 hours. The thickness of the composite heat insulation coating is approximately 200 μm.

[0043] Example 3

[0044] In this embodiment, a LaZr alloy target was prepared using La and Zr as raw materials through vacuum induction melting and rapid cooling technology. The high-temperature alloy substrate was made of nickel-chromium-iron-based GH3536 high-temperature alloy, with NiCrAlY alloy as the metal binder layer and 6% Y2O3 partially stabilized ZrO2 as the ceramic transition layer. The surface of the alloy target was first bombarded and cleaned for 5-10 minutes. Argon gas was introduced before pre-sputtering at a flow rate of 20-30 mL / min. Then, the pre-sputtered alloy target was sputtered onto the surface of the ceramic transition layer of the alloy substrate, while oxygen was introduced at a flow rate of 20 mL / min. The sputtering environment temperature was controlled at 400℃, and sputtering was carried out for 7 hours to obtain a La2Zr2O7 composite heat-insulating coating with a thickness of about 220 μm.

[0045] Example 4

[0046] In this embodiment, GdZr alloy targets were prepared using vacuum induction melting and rapid cooling technology with Gd and Zr as raw materials. The high-temperature alloy substrate was made of nickel-chromium-iron-based GH3536 high-temperature alloy, with NiCrAlY alloy as the metal binder layer and 6% Y2O3 partially stabilized ZrO2 as the ceramic transition layer. The surface of the alloy target was first bombarded and cleaned for 5-10 minutes. Argon gas was introduced before pre-sputtering at a flow rate of 20-30 mL / min. Then, the pre-sputtered alloy target was sputtered onto the surface of the ceramic transition layer of the alloy substrate, while oxygen was introduced at a flow rate of 20 mL / min. The sputtering environment temperature was controlled at 400℃, and sputtering was carried out for 8 hours to obtain a Gd2Zr2O7 composite heat-insulating coating with a thickness of about 280 μm.

[0047] Example 5

[0048] In this embodiment, a LaCe alloy target was prepared using La and Ce as raw materials through vacuum induction melting and rapid cooling technology. The high-temperature alloy matrix material was a nickel-chromium-iron-based GH3536 high-temperature alloy, with a PtAl alloy as the binder layer and a 7% Y2O3 partially stabilized ZrO2 as the ceramic transition layer. The surface of the alloy target was first bombarded and cleaned for 5-10 minutes. Argon gas was introduced before pre-sputtering at a flow rate of 20-30 mL / min. Then, the pre-sputtered alloy target was sputtered onto the surface of the ceramic transition layer of the alloy matrix, while oxygen was introduced at a flow rate of 15 mL / min. The sputtering environment temperature was controlled at 300℃, and a La2Ce2O7 composite heat-insulating coating was obtained after sputtering for 9 hours. The thickness of this composite heat-insulating coating was about 200 μm.

[0049] Example 6

[0050] In this embodiment, SmZr alloy targets were prepared using vacuum induction melting and rapid cooling technology with Sm and Zr as raw materials. The high-temperature alloy matrix material was a nickel-chromium-iron-based GH3536 high-temperature alloy, with a NiCoCrAlYHf alloy as the binder layer and a 7% Y2O3 partially stabilized ZrO2 as the ceramic transition layer. The surface of the alloy target was first bombarded and cleaned for 5-10 minutes. Argon gas was introduced before pre-sputtering at a flow rate of 20-30 mL / min. Then, the pre-sputtered alloy target was sputtered onto the surface of the ceramic transition layer of the alloy matrix, while oxygen was introduced at a flow rate of 20 mL / min. The sputtering environment temperature was controlled at 400℃, and a Sm2Zr2O7 composite heat-insulating coating was obtained after sputtering for 5 hours. The thickness of this composite heat-insulating coating was about 200 μm.

[0051] Example 7

[0052] In this embodiment, La was produced using vacuum induction melting and rapid cooling technology with La, Sm, and Zr as raw materials. 1.8 Sm 0.2 Zr2 alloy target material. The high-temperature alloy matrix material is nickel-chromium-iron-based GH3536 high-temperature alloy, with NiCoCrAlYHf alloy as the binder layer and 6% Y2O3 partially stabilized ZrO2 as the ceramic transition layer. The surface of the alloy target material is first bombarded and cleaned for 5-10 minutes. Argon gas is introduced before pre-sputtering at a flow rate of 20-30 mL / min. Then, the pre-sputtered alloy target material is sputtered onto the surface of the ceramic transition layer of the alloy matrix, while oxygen gas is introduced at a flow rate of 30 mL / min and nitrogen gas at a flow rate of 10 mL / min. The sputtering environment temperature is controlled at 450℃. After sputtering for 8 hours, (La) 0.9 Sm 0.1The Zr2O7 composite thermal insulation coating was further oxidized by introducing oxygen at 60 mL / min into an 850℃ furnace and holding it at that temperature for 4 hours. The thickness of the composite thermal insulation coating was about 300 μm.

[0053] Example 8

[0054] In this embodiment, La was produced using La, Dy, and Zr as raw materials and vacuum induction melting and rapid cooling technology. 1.8 Dy 0.2 Zr2 alloy target material. The high-temperature alloy matrix material is nickel-chromium-iron-based GH3536 high-temperature alloy, with NiCoCrAlYHf alloy as the binder layer and 6% Y2O3 partially stabilized ZrO2 as the ceramic transition layer. The surface of the alloy target material is first bombarded and cleaned for 5-10 minutes. Before pre-sputtering, argon gas is introduced at a flow rate of 20-30 mL / min. Then, the pre-sputtered alloy target material is sputtered onto the surface of the ceramic transition layer of the alloy matrix, while oxygen is introduced at a flow rate of 30 mL / min and argon at a flow rate of 1 mL / min. The sputtering environment temperature is controlled at 450℃. After sputtering for 8 hours, (La) 0.9 Dy 0.1 The Zr2O7 composite heat insulation coating was further oxidized by purging oxygen at 65 mL / min and nitrogen at 5 mL / min in an 850℃ furnace, while being kept at the same temperature for 4 hours. The thickness of the composite heat insulation coating was about 200 μm.

[0055] Example 9

[0056] In this embodiment, Gd is produced using vacuum induction melting and rapid cooling technology with Gd, Er, Zr, and Ti as raw materials. 1.8 Er 0.2 Zr 1.4 Ti 0.6 Alloy target material. The high-temperature alloy matrix material is nickel-chromium-iron-based GH3536 high-temperature alloy, with PtAl alloy as the binder layer and 6% Y2O3 partially stabilized ZrO2 as the ceramic transition layer. The alloy target surface is first bombarded and cleaned for 5-10 minutes. Before pre-sputtering, argon gas is introduced at a flow rate of 20-30 mL / min. Then, the pre-sputtered alloy target is sputtered onto the ceramic transition layer surface of the alloy matrix, while oxygen is introduced at a flow rate of 50 mL / min. The sputtering environment temperature is controlled at 800℃, and sputtering is carried out for 8 hours to obtain (Gd... 0.9 Er 0.1 )2(Zr 0.7 Ti 0.3 The 2O7 composite heat insulation coating was placed in an 850℃ furnace and further oxidized by introducing oxygen at a rate of 65 mL / min and argon at a rate of 5 mL / min, while being kept at the same temperature for 6 hours. The thickness of the composite heat insulation coating was approximately 200 μm.

[0057] Examples 10-13

[0058] In this embodiment, La2(Ce) was prepared by vacuum induction melting and rapid cooling technology using La, Ce, and Zr as raw materials. 1-y Zr y 2. Alloy Target Material. The high-temperature alloy matrix material is nickel-chromium-iron-based GH3536 high-temperature alloy, with PtAl alloy as the binder layer and 6% Y2O3 partially stabilized ZrO2 as the ceramic transition layer. The surface of the alloy target material is first bombarded and cleaned for 5-10 minutes. Before pre-sputtering, argon gas is introduced at a flow rate of 20-30 mL / min. Then, the pre-sputtered alloy target material is sputtered onto the surface of the ceramic transition layer of the alloy matrix, while oxygen is introduced at a flow rate of 30 mL / min and dry air at a flow rate of 10 mL / min. The sputtering environment temperature is controlled at 350℃, 400℃, 450℃, and 500℃, respectively. Sputtering is carried out for 7 h to obtain the corresponding La2(Ce) ... 1-y Zr y The 2O7 composite heat insulation coating was placed in a furnace at 650℃ and further oxidized by introducing oxygen at 25 mL / min and argon at 15 mL / min, while being kept at the temperature for 6 hours. The composite heat insulation coatings prepared in Examples 10-13 are shown in Table 1. The thickness of each composite heat insulation coating is about 200 μm.

[0059] Examples 14-17

[0060] This embodiment uses La, Sm, Ce, and Zr as raw materials and employs vacuum induction melting and rapid cooling technology to produce (La) a Sm 1-a )2(Ce 1-y Zr y )2 alloy target material, 0≤a≤1. The high-temperature alloy matrix material is nickel-chromium-iron-based GH3536 high-temperature alloy, with PtAl alloy as the binder layer and 6% Y2O3 partially stabilized ZrO2 as the ceramic transition layer. The surface of the alloy target material is first bombarded and cleaned for 5~10 minutes. Argon gas is introduced before pre-sputtering at a flow rate of 20~30 mL / min. Then, the pre-sputtered alloy target material is sputtered onto the surface of the ceramic transition layer of the alloy matrix, while oxygen is introduced at a flow rate of 30 mL / min and dry air at a flow rate of 10 mL / min. The sputtering environment temperature is controlled at 500℃, and sputtering is carried out for 7 hours to obtain the corresponding (La) a Sm 1-a )2(Ce 1-y Zr y The 2O7 composite heat insulation coating was placed in a furnace at 700℃, 750℃, 800℃, and 850℃, and further oxidized by introducing oxygen at a rate of 25 mL / min and argon at a rate of 15 mL / min, while being kept at the same temperature for 6 hours. The composite heat insulation coatings prepared in Examples 14-17 are shown in Table 1. The thickness of each composite heat insulation coating is about 200 μm.

[0061] Example 18

[0062] In this embodiment, La was produced using vacuum induction melting and rapid cooling technology with La, Yb, Ce, and Zr as raw materials. 1.4 Yb 0.6 Ce 0.6 Zr 1.4 Alloy target material. The high-temperature alloy matrix material is nickel-chromium-iron-based GH3536 high-temperature alloy, with NiCoCrAlYHf alloy as the binder layer and 6% Y2O3 partially stabilized ZrO2 as the ceramic transition layer. The alloy target surface is first bombarded and cleaned for 5-10 minutes. Before pre-sputtering, argon gas is introduced at a flow rate of 20-30 mL / min. Then, the pre-sputtered alloy target is sputtered onto the ceramic transition layer surface of the alloy matrix, while oxygen is introduced at a flow rate of 50 mL / min. The sputtering environment temperature is controlled at 500℃, and sputtering is carried out for 12 hours to obtain (La) 0.7 Yb 0.3 )2(Ce 0.3 Zr 0.7 The 2O7 composite heat insulation coating was further oxidized by introducing oxygen at a rate of 100 mL / min into a furnace at 750℃ and keeping it at that temperature for 7 hours. The thickness of the composite heat insulation coating was approximately 200 μm.

[0063] Example 19

[0064] In this embodiment, La₂Zr was produced using La, Zr, and Hf as raw materials through vacuum induction melting and rapid cooling technology. 1.8 Hf 0.2 Alloy target material. The high-temperature alloy matrix material is nickel-chromium-iron-based GH3536 high-temperature alloy, with PtAl alloy as the binder layer and 6% Y2O3 partially stabilized ZrO2 as the ceramic transition layer. The alloy target surface is first bombarded and cleaned for 5-10 minutes. Before pre-sputtering, argon gas is introduced at a flow rate of 20-30 mL / min. Then, the pre-sputtered alloy target is sputtered onto the ceramic transition layer surface of the alloy matrix, while oxygen is introduced at a flow rate of 70 mL / min. The sputtering environment temperature is controlled at 500℃. La2Zr obtained after 6 hours of sputtering. 1.8 Hf 0.2 The O7 composite heat insulation coating is further oxidized by purging oxygen at 10 mL / min in a 1000℃ furnace and keeping it at that temperature for 10 hours. The thickness of this composite heat insulation coating is about 200 μm.

[0065] Example 20

[0066] In this embodiment, a LaGe alloy target was prepared using La and Ge as raw materials through vacuum induction melting and rapid cooling technology. The high-temperature alloy matrix material was a nickel-chromium-iron-based GH3536 high-temperature alloy, with a PtAl alloy as the binder layer and a 6% Y2O3 partially stabilized ZrO2 as the ceramic transition layer. The surface of the alloy target was first bombarded and cleaned for 5-10 minutes. Argon gas was introduced before pre-sputtering at a flow rate of 20-30 mL / min. Then, the pre-sputtered alloy target was sputtered onto the surface of the ceramic transition layer of the alloy matrix, while oxygen was introduced at a flow rate of 90 mL / min. The sputtering environment temperature was controlled at 200℃. After sputtering for 3 hours, a La2Ge2O7 composite heat-insulating coating was obtained. The coating was then placed in a 500℃ furnace with dry air introduced at a flow rate of 5 mL / min for further oxidation treatment, while being held at that temperature for 4 hours. The thickness of this composite heat-insulating coating was approximately 150 μm.

[0067] Example 21

[0068] In this embodiment, a LaSn alloy target was prepared using La and Sn as raw materials through vacuum induction melting and rapid cooling technology. The high-temperature alloy matrix material was a nickel-chromium-iron-based GH3536 high-temperature alloy, with a PtAl alloy as the binder layer and a 6% Y2O3 partially stabilized ZrO2 as the ceramic transition layer. The surface of the alloy target was first bombarded and cleaned for 5-10 minutes. Before pre-sputtering, argon gas was introduced at a flow rate of 20 mL / min. Then, the pre-sputtered alloy target was sputtered onto the surface of the ceramic transition layer of the alloy matrix, while oxygen was introduced at a flow rate of 5 mL / min. The sputtering environment temperature was controlled at 100℃. After sputtering for 2 hours, a La2Sn2O7 composite heat-insulating coating was obtained. The coating was then placed in a 400℃ furnace and further oxidized by introducing dry air at a flow rate of 10 mL / min, while holding at that temperature for 2 hours. The thickness of this composite heat-insulating coating was approximately 100 μm.

[0069] Example 22

[0070] In this embodiment, Gd is produced using Gd, Yb, and Zr as raw materials through vacuum induction melting and rapid cooling technology. 1.33 Yb 0.57 Zr 2.1 Alloy target material. The high-temperature alloy matrix material is nickel-chromium-iron-based GH3536 high-temperature alloy, with PtAl alloy as the binder layer and 6% Y2O3 partially stabilized ZrO2 as the ceramic transition layer. The alloy target surface is first bombarded and cleaned for 5-10 minutes. Before pre-sputtering, argon gas is introduced at a flow rate of 20-30 mL / min. Then, the pre-sputtered alloy target is sputtered onto the ceramic transition layer surface of the alloy matrix, while oxygen is introduced at a flow rate of 30 mL / min. The sputtering environment temperature is controlled at 450℃, and sputtering is carried out for 11 hours to obtain (Gd... 0.7 Yb 0.3 ) 1.9 Zr 2.1 O 6.75The composite heat insulation coating was further oxidized by introducing oxygen at a rate of 50 mL / min into an 850°C furnace and holding it at that temperature for 6 hours. The thickness of the composite heat insulation coating was approximately 200 μm.

[0071] Example 23

[0072] In this embodiment, La was produced using vacuum induction melting and rapid cooling technology with La, Yb, and Zr as raw materials. 1.26 Yb 0.54 Zr 2.2 Alloy target material. The high-temperature alloy matrix material is nickel-chromium-iron-based GH3536 high-temperature alloy, with PtAl alloy as the binder layer and 6% Y2O3 partially stabilized ZrO2 as the ceramic transition layer. The alloy target surface is first bombarded and cleaned for 5-10 minutes. Before pre-sputtering, argon gas is introduced at a flow rate of 20-30 mL / min. Then, the pre-sputtered alloy target is sputtered onto the ceramic transition layer surface of the alloy matrix, while oxygen is introduced at a flow rate of 30 mL / min. The sputtering environment temperature is controlled at 450℃. After sputtering for 10 hours, (La) is obtained. 0.7 Yb 0.3 ) 1.8 Zr 2.2 O 7.1 The composite heat insulation coating was further oxidized by introducing oxygen at a rate of 50 mL / min into an 850°C furnace and holding it at that temperature for 6 hours. The thickness of the composite heat insulation coating was approximately 200 μm.

[0073] Compared to the near-high temperatures of 10,000°C encountered during atmospheric plasma spraying and plasma physical vapor deposition (PVD) processes, the conventional sputtering process employed in this invention avoids coating composition deviations caused by the volatilization of certain components and differences in vapor pressure between different elements. Furthermore, it requires less equipment investment and has lower production costs. Energy dispersive spectroscopy (EDS) was used to analyze the composition of the prepared coatings in each embodiment. The results in Table 1 show that the actual coating composition is consistent with the designed composition. In addition, magnetron sputtering equipment is less expensive and easier to operate than EB-PVD equipment.

[0074] Comparative Example 1

[0075] This comparative example uses a La2Ce2O7 ceramic ingot as the sputtering target, a nickel-chromium-iron-based GH3536 high-temperature alloy as the substrate, a PtAl alloy as the binder layer, and a 6% Y2O3 partially stabilized ZrO2 as the ceramic underlayer. An EB-PVD method was used to prepare the La2Ce2O7 ceramic coating. The La2Ce2O7 ceramic ingot was evaporated by electron beam heating. The workpiece was rotated on a rotating shaft at a speed of 15 rad / min, and the coating deposition time was 40 min. The final coating thickness was approximately 200 μm. Energy dispersive spectroscopy (EDS) analysis of the coating composition showed that the actual composition of the coating was La2Ce. 1.85 O6.7 The composition deviates from that of La2Ce2O7 ceramic ingots. In addition, EB-PVD equipment is expensive and complex to operate.

[0076] Comparative Example 2

[0077] This comparative example uses (Gd) 0.9 Yb 0.1 Zr2O7 ceramic ingots were used as sputtering targets, with nickel-chromium-iron-based GH3536 high-temperature alloy as the substrate material. PtAl alloy was used as the bonding layer, and 6% Y2O3 partially stabilized ZrO2 was used as the ceramic underlayer. The sputtering was carried out using the EB-PVD method. 0.9 Yb 0.1 The surface of the 2Zr2O7 ceramic coating was evaporated by electron beam heating (Gd) 0.9 Yb 0.1 A Zr₂O₇ ceramic ingot was used, and the workpiece was rotated by a rotating shaft at a speed of 15 rad / min. The coating deposition time was 140 min, and the final coating thickness was approximately 200 μm. Energy dispersive spectroscopy (EDS) analysis of the coating composition showed that the actual composition of the coating was (Gd₂O₇)₂. 0.85 Yb 0.08 )2Zr2O 6.79 , and (Gd 0.9 Yb 0.1 The composition of the 2Zr2O7 ceramic ingot deviates somewhat from that of the EB-PVD ingot. Furthermore, EB-PVD equipment is expensive and complex to operate.

[0078] Table 1. Process parameters and comparison results for each embodiment

[0079]

[0080] As shown in Table 1, the embodiments of the present invention, through precise control of the multi-component alloy target material composition and the oxidation atmosphere flow rate during the oxidation process, along with the control of sputtering reaction temperature, time, and furnace temperature during the oxidation process in physical deposition technology, can prepare oxide coatings with specific compositions that are consistent with the design composition. This effectively avoids the coating composition deviation problem caused by the difference in supersaturated vapor pressure of each component during thermal spraying and plasma physical vapor deposition, thereby obtaining a heat-insulating coating that conforms to the composition design and ensuring that the obtained coating conforms to the stoichiometry, thus improving the performance of the coating. In contrast, Comparative Examples 1 and 2, which use EB-PVD method to prepare oxide coatings with oxide ceramic targets, show a serious deviation from the design composition during the sputtering process. Furthermore, the thermal conductivity values ​​of the embodiments prepared by the present invention are all lower than those of the comparative examples, demonstrating the superiority of the present method.

[0081] This invention relates to a composite thermal insulation coating containing rare earth oxides, its preparation method, and its application. By precisely controlling the composition of the multi-component alloy target and the oxidation atmosphere and process conditions during the oxidation treatment, the coating composition deviation caused by differences in properties such as supersaturated vapor pressure of each component during thermal spraying and plasma physical vapor deposition is effectively avoided. This results in a thermal insulation coating that conforms to the component design, ensuring that the obtained coating meets stoichiometry, thereby improving the coating's performance. Compared to EB-PVD equipment, magnetron sputtering equipment is lower in cost and easier to operate.

Claims

1. A method for preparing a composite heat-insulating coating containing rare earth oxides, characterized in that, A composite thermal insulation coating containing rare earth oxides is prepared on a high-temperature alloy substrate, wherein the composite thermal insulation coating has the composition (RE). 2-x (Ce 1-y M y ) 2+x O 7±z RE is at least one rare earth element other than Ce, M is at least one metallic element other than rare earth elements, 0≤x≤0.5, 0≤y≤1, 0≤z≤0.5, and the preparation method of the composite heat-insulating coating includes the following steps: S1, according to the preset stoichiometric ratio, non-Ce rare earth metal RE, metal Ce and metal M are prepared into RE-Ce-M alloy target; S2, a metal bonding layer is first prepared on the high-temperature alloy substrate, and then a ceramic transition layer is prepared on the metal bonding layer; S3, the RE-Ce-M alloy target is sputtered onto the surface of the ceramic transition layer, and an oxidizing atmosphere is introduced to form a composite heat-insulating coating containing rare earth oxides on the high-temperature alloy substrate.

2. The method for preparing the composite heat-insulating coating containing rare earth oxides according to claim 1, characterized in that, The RE is at least one of La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Sc, and Y, and the M is at least one of Zr, Ti, Ge, Sn, Th, Hf, Si, Al, Nb, Ta, Sr, Mg, and Ca.

3. The method for preparing the composite heat-insulating coating containing rare earth oxides according to claim 1, characterized in that, The oxidizing atmosphere in step S3 includes oxygen, a mixture of oxygen and air, a mixture of oxygen and nitrogen, and a mixture of oxygen and inert gases.

4. The method for preparing the composite heat-insulating coating containing rare earth oxides according to claim 1, characterized in that, In step S3, the sputtering reaction temperature is 100℃~800℃, and the sputtering reaction time is 2~12 h.

5. The method for preparing the composite heat-insulating coating containing rare earth oxides according to claim 1, characterized in that, The preparation method further includes step S4, which involves heat-treating the obtained composite heat-insulating coating containing rare earth oxides.

6. The method for preparing the composite heat-insulating coating containing rare earth oxides according to claim 5, characterized in that, The heat treatment temperature is 400℃~1000℃, and the holding time is 2 h~10 h.

7. The method for preparing the composite heat-insulating coating containing rare earth oxides according to claim 5, characterized in that, The heat treatment process introduces an oxidizing atmosphere, which is the same as in step S3.

8. The method for preparing the composite heat-insulating coating containing rare earth oxides according to claim 1, characterized in that, The thickness of the composite heat insulation coating is 20μm to 400μm.

9. The method for preparing the composite heat-insulating coating containing rare earth oxides according to claim 1, characterized in that, The composition of the metal bonding layer includes PtAl, NiCoCrAlY, NiCrAlY, NiCoCrAlYHf and NiCoCrAlYSi, and the thickness of the metal bonding layer is 20μm to 200μm.

10. The method for preparing the composite heat-insulating coating containing rare earth oxides according to claim 1, characterized in that, The main component of the ceramic transition layer includes rare earth-containing zirconium-based oxide, and the thickness of the ceramic transition layer is 20 μm to 400 μm.

11. A composite heat-insulating coating containing rare earth oxides, characterized in that, The rare earth oxide-containing composite heat-insulating coating is obtained by the preparation method of the rare earth oxide-containing composite heat-insulating coating according to any one of claims 1-10, wherein the rare earth oxide-containing composite heat-insulating coating is distributed on a high-temperature alloy substrate and has a composition of (RE). 2-x (Ce 1-y M y ) 2+x O 7±z RE is at least one rare earth element other than Ce, M is at least one metallic element other than rare earth elements, 0≤x≤0.5, 0≤y≤1, 0≤z≤0.

5.

12. The composite heat-insulating coating containing rare earth oxides according to claim 11, characterized in that, Between the high-temperature alloy substrate and the composite thermal insulation coating, there is also a metal bonding layer and a ceramic transition layer distributed from bottom to top, and the composite thermal insulation coating is deposited on the surface of the ceramic transition layer.

13. The composite heat-insulating coating containing rare earth oxides according to claim 11, characterized in that, The RE is at least one of La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Sc, and Y, and the M is at least one of Zr, Ti, Ge, Sn, Th, Hf, Si, Al, Nb, Ta, Sr, Mg, and Ca.

14. The application of a composite thermal insulation coating containing rare earth oxides in the field of thermal protection for high-temperature alloys and equipment, characterized in that, The composite heat insulation coating is obtained by the preparation method of the rare earth oxide-containing composite heat insulation coating according to any one of claims 1-10.

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