Thermal barrier coating surface modification method

Abstract

The invention belongs to the field of protective coatings, and particularly discloses a thermal barrier coating surface modification method which comprises the following steps: sequentially forming an alloy layer and an aluminum layer on the surface of a thermal barrier coating to obtain a thermal barrier coating containing a modified coating; the thermal barrier coating containing the modified coating is subjected to heat treatment; the alloy layer contains aluminum and rare earth elements. According to the surface modification method of the thermal barrier coating, rare earth elements are introduced into the alloy layer, so that the in-situ reaction activity of the alloy layer and the surface of the thermal barrier coating is improved, a large number of Al3Zr intermediates with fine and uniform crystal grains are generated in the alloy layer, the interface energy caused by the in-situ reaction is reduced, complete coating is formed on the surface of the thermal barrier coating, and the surface of the thermal barrier coating is improved. And the CMAS corrosion resistance of the coating is obviously improved. In addition, surface modification is simple and easy to operate, and the method is suitable for large-scale popularization and application.

Description

Technical Field

[0001] The invention belongs to the field of protective coatings, and in particular relates to a surface modification method of a thermal barrier coating. Background Art

[0002] Thermal barrier coatings are low thermal conductivity ceramic materials with certain functions, which are compounded on the surface of high-temperature components in the form of coatings or films, making them resistant to high temperatures, corrosion, wear, and heat insulation. They are widely used in aviation, aerospace, energy, and other fields. With the development of thermal barrier coatings, the preparation technology of coatings has received more and more attention. The different preparation technologies directly affect the microstructure of thermal barrier coatings, and then affect the service life of protected components such as engine turbine blades.

[0003] As people's understanding of the failure mechanism of thermal barrier coatings deepens, thermal corrosion has become an important factor in the failure of thermal barrier coatings, and CMAS (the abbreviation of aluminum silicate substances such as CaO2, MgO, Al2O3, SiO2) corrosion is the most serious among thermal corrosion. CMAS mainly comes from dust, sand and gravel, aircraft runway wear debris, and engine front-stage component peelings. When an aircraft engine is in service, CMAS will be sucked into the engine through the intake duct, and after being heated by the compressor and combustion chamber at high temperature, it will become a molten body adsorbed on the surface of the ceramic layer and undergo a thermochemical reaction with the coating, thereby causing the coating to fail prematurely.

[0004] When CMAS penetrates into the pores of the YSZ coating, it will destroy the structure of the ceramic layer, which will have a significant impact on the mechanical properties. The thermomechanical effect of CMAS on the thermal barrier coating is not single. First, after melting, CMAS adheres to, penetrates and corrodes the YSZ layer, which has the effect of impact compacting the ceramic layer and densifying after cooling and mutual dissolution, and produces large internal stress, which leads to failure of the thermal barrier coating such as delamination and peeling; secondly, based on the thermochemical effect, the Y of YSZ is absorbed, resulting in the crystal transformation of zirconium oxide, which in turn leads to mechanical effects such as volume change and internal stress. Summary of the invention

[0005] In order to overcome at least one technical problem existing in the above-mentioned prior art, one of the objectives of the present invention is to provide a surface modification method of a thermal barrier coating.

[0006] A second object of the present invention is to provide a protective coating.

[0007] A third object of the present invention is to provide an engine.

[0008] A fourth object of the present invention is to provide a surface modification method for the thermal barrier coating and / or application of the protective coating in the fields of aviation, aerospace, national defense weapons and equipment or energy.

[0009] In order to achieve the above object, the technical solution adopted by the present invention is:

[0010] A first aspect of the present invention provides a method for surface modification of a thermal barrier coating, comprising the following steps:

[0011] An alloy layer and an aluminum layer are sequentially formed on the surface of the thermal barrier coating to obtain a thermal barrier coating containing a modified coating;

[0012] heat-treating the thermal barrier coating containing the modified coating;

[0013] The alloy layer contains aluminum and rare earth elements.

[0014] In the heat treatment step, the alloy layer reacts with the thermal barrier coating in situ to generate Al3Zr.

[0015] In some embodiments of the present invention, the thermal barrier coating contains zirconium.

[0016] In some embodiments of the present invention, the heat treatment step is performed under vacuum.

[0017] In some embodiments of the present invention, the temperature of the heat treatment step is 400-1100°C.

[0018] In some embodiments of the present invention, the heat treatment step is performed for 4 to 10 hours.

[0019] In some embodiments of the present invention, the heat treatment step is: first keep warm at 400-550°C for 100-150 min; then keep warm at 600-750°C for 40-80 min; and then keep warm at 800-1100°C for 80-120 min.

[0020] In some embodiments of the present invention, the rare earth element is selected from at least one of lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium and yttrium.

[0021] In some embodiments of the present invention, the mass percentage of the rare earth element in the alloy layer is 5% to 50%.

[0022] In some embodiments of the present invention, the mass percentage of aluminum in the alloy layer is 50-95%.

[0023] In some embodiments of the present invention, the step of sequentially forming an alloy layer and an aluminum layer on the surface of the thermal barrier coating comprises: sequentially depositing an alloy layer and an aluminum layer on the surface of the thermal barrier coating by a vacuum arc ion plating method or a magnetron sputtering method.

[0024] In some embodiments of the present invention, the bias voltage of the vacuum arc ion plating method during deposition is 120-140V.

[0025] In some embodiments of the present invention, the current during deposition in the vacuum arc ion plating method is 60-80A.

[0026] In some embodiments of the present invention, the working gas during deposition in the vacuum arc ion plating method is an inert gas.

[0027] In some embodiments of the present invention, the gas flow rate during metal deposition in the vacuum arc ion plating method is 21-28 sccm.

[0028] In some embodiments of the present invention, the bias voltage during the magnetron sputtering method during deposition is 50-140V.

[0029] In some embodiments of the present invention, the working gas during the deposition by the magnetron sputtering method is an inert gas.

[0030] In some embodiments of the present invention, the gas flow rate during deposition in the magnetron sputtering method is 140-180 sccm.

[0031] In some embodiments of the present invention, the rotation speed of the turntable during the magnetron sputtering method is 3 to 10 rpm.

[0032] In some embodiments of the present invention, the deposition temperature during the magnetron sputtering method is 250-350°C.

[0033] In some embodiments of the present invention, the vacuum degree of the magnetron sputtering method during deposition is 3×10 -3 ~8×10 -3 Pa.

[0034] In some embodiments of the present invention, the magnetron sputtering method further requires target refining before deposition.

[0035] In some embodiments of the present invention, the target refining temperature is 300-400°C.

[0036] In some embodiments of the present invention, the target refining bias voltage is 400-600V.

[0037] In some embodiments of the present invention, the target refining magnetic field strength is set to a bias voltage of 7.5 to 8.5 V and a frequency of 8 to 9 Hz.

[0038] In some embodiments of the present invention, the vacuum degree of the target smelting is 3×10 -2 ~8×10 -2 Pa.

[0039] In some embodiments of the present invention, the thermal barrier coating is a YSZ thermal barrier coating (ie, yttria-stabilized zirconia thermal barrier coating).

[0040] In some embodiments of the present invention, the YSZ thermal barrier coating comprises 5% to 10% by mass of yttrium oxide and 90% to 95% by mass of zirconium oxide.

[0041] In some embodiments of the present invention, the alloy layer has a thickness of 1 μm to 10 μm.

[0042] In some embodiments of the present invention, the thickness of the aluminum layer is 1 μm to 10 μm.

[0043] The second aspect of the present invention provides a protective coating, wherein the protective coating contains Al3Zr; the protective coating is prepared by the surface modification method described in the first aspect of the present invention. The Al3Zr in the protective coating is generated by an in-situ reaction between zirconium in the thermal barrier coating and Al in the alloy layer.

[0044] A third aspect of the present invention provides an engine, comprising turbine blades, on which the protective coating according to the second aspect of the present invention is provided.

[0045] The fourth aspect of the present invention provides the surface modification method of the thermal barrier coating described in the first aspect of the present invention and / or the application of the protective coating described in the second aspect of the present invention in the fields of aviation, aerospace, national defense weapons and equipment or energy.

[0046] The beneficial effects of the present invention are as follows: the surface modification method of the thermal barrier coating of the present invention improves the in-situ reaction activity of the alloy layer and the surface of the thermal barrier coating by introducing rare earth elements into the alloy layer, so that a large number of Al3Zr intermediates with fine and uniform grains are generated in the alloy layer, the interfacial energy caused by the in-situ reaction is reduced, and a complete coating is formed on the surface of the thermal barrier coating, which significantly improves the CMAS corrosion resistance of the coating. In addition, the surface modification in the present invention is simple and easy to operate, and is suitable for mass promotion and application.

[0047] The Al3Zr intermediate in the alloy layer of the protective coating of the present invention undergoes a surface reaction during service to generate ZrO2 in situ, thereby extending the service life of the protective coating, improving the impact resistance, CMAS corrosion resistance, thermal stability and other properties of the protective coating, and enabling the protective coating of the present invention to be used for thermal protection of hot end components of gas turbine turbines. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 This is a scanning electron microscope image of the modified coating after modification by the modification method in Example 1.

[0049] Figure 2 This is a scanning electron microscope image of the modified coating after modification by the modification method in Comparative Example 1.

[0050] Figure 3This is the XRD diagram of the modified coating after modification by the modification method in Example 1.

[0051] Figure 4 This is the XRD diagram of the modified coating after the modification treatment by the modification method in Example 1 after simulated service.

[0052] Figure 5 This is a physical picture of the modified coating after modification by the modification method in Example 1 and Comparative Example 2.

[0053] Figure 6 The actual pictures are of the modified coating of Example 1 and the unmodified YSZ thermal barrier coating after water cooling and thermal shock.

[0054] Figure 7 This is the EDS energy spectrum of the modified coating in Example 1 after CMAS corrosion for 20 hours.

[0055] Figure 8 This is the EDS energy spectrum of the unmodified YSZ thermal barrier coating after CMAS corrosion for 20 hours. DETAILED DESCRIPTION

[0056] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples, but the implementation and protection of the present invention are not limited thereto. It should be noted that if there are processes that are not particularly described in detail below, they can be implemented or understood by those skilled in the art with reference to the prior art. The reagents or instruments used that do not indicate the manufacturer are all conventional products that can be purchased commercially.

[0057] In some embodiments of the present invention, the present invention provides a surface modification method of a thermal barrier coating, comprising the following steps:

[0058] An alloy layer and an aluminum layer are sequentially formed on the surface of the thermal barrier coating to obtain a thermal barrier coating containing a modified coating;

[0059] heat treating the thermal barrier coating including the modified coating;

[0060] The alloy layer contains aluminum and rare earth elements.

[0061] During the heat treatment process, the thermal barrier coating reacts with the alloy layer in situ, so that the surface of the thermal barrier coating is completely covered. This method improves the coverage of the thermal barrier coating (for example, when the thermal barrier coating is a YSZ thermal barrier coating, the surface of the YSZ columnar crystal is completely covered by the modified coating), and during the service of the thermal barrier coating, the Al3Zr intermediate reacts in situ on the coating surface to continuously form ZrO2, thereby improving the service life of the coating and enhancing the coating's resistance to CMAS (CaO2, MgO, Al2O3, SiO2) corrosion during service.

[0062] In some embodiments of the present invention, the thermal barrier coating contains zirconium element, and the zirconium element reacts in situ with the aluminum element of the alloy layer during the heat treatment process to generate Al3Zr intermediate.

[0063] In some embodiments of the present invention, the heat treatment step is performed under vacuum.

[0064] In some embodiments of the present invention, the temperature of the heat treatment step is 400-1100°C; in some embodiments of the present invention, the temperature of the heat treatment step can be any value among 400°C, 450°C, 500°C, 550°C, 600°C, 650°C, 700°C, 750°C, 800°C, 850°C, 900°C, 950°C, 1000°C, 1050°C, 1100°C or a range formed by any two of them.

[0065] In some embodiments of the present invention, the time of the heat treatment step is 4 to 10 hours; in some embodiments of the present invention, the time of the heat treatment step can be any value among 4h, 5h, 6h, 7h, 8h, 9h, 10h or a range formed by any two of them.

[0066] In some embodiments of the present invention, the heat treatment step is: first keep the temperature at 400-550°C for 100-150 minutes; then keep the temperature at 600-750°C for 40-80 minutes; then keep the temperature at 800-1100°C for 80-120 minutes. In some embodiments of the present invention, the heat treatment step is: first keep the temperature at 450-550°C for 110-130 minutes; then keep the temperature at 650-750°C for 50-70 minutes; then keep the temperature at 850-1000°C for 90-110 minutes.

[0067] In some embodiments of the present invention, the vacuum degree of the heat treatment step is not higher than 2×10 -2 Pa.

[0068] In some embodiments of the present invention, the rare earth element is selected from at least one of lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium, and yttrium.

[0069] In some embodiments of the present invention, the mass percentage of rare earth elements in the alloy layer is 5% to 50%; in some embodiments of the present invention, the mass percentage of rare earth elements in the alloy layer can be any value among 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50% or a range formed by any two of them.

[0070] In some embodiments of the present invention, the mass percentage of aluminum element in the alloy layer is 50-95%; in some embodiments of the present invention, the mass percentage of aluminum element in the alloy layer is 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, any one of the values ​​or a range formed by any two of them.

[0071] In some embodiments of the present invention, the steps of sequentially forming an alloy layer and an aluminum layer on the surface of the thermal barrier coating are: sequentially depositing an alloy layer and an aluminum layer on the surface of the thermal barrier coating by a vacuum arc ion plating method or a magnetron sputtering method.

[0072] In some embodiments of the present invention, the bias voltage of the vacuum arc ion plating method during deposition is 120-140V; in some embodiments of the present invention, the bias voltage of the vacuum arc ion plating method during deposition can be any value among 120V, 125V, 130V, 135V, 140V or a range formed by any two of them.

[0073] In some embodiments of the present invention, the current of the vacuum arc ion plating method during deposition is 60-80A; in some embodiments of the present invention, the current of the vacuum arc ion plating method during deposition is any one of 60A, 65A, 70A, 75A, 80A or a range formed by any two of them.

[0074] In some embodiments of the present invention, the working gas during deposition in the vacuum arc ion plating method is an inert gas.

[0075] In some embodiments of the present invention, the gas flow rate of the vacuum arc ion plating method when depositing metal is 21 to 28 sccm; in some embodiments of the present invention, the gas flow rate of the vacuum arc ion plating method when depositing metal can be any value among 21 sccm, 22 sccm, 23 sccm, 24 sccm, 25 sccm, 26 sccm, 27 sccm, 28 sccm or a range formed by any two of them.

[0076] In some embodiments of the present invention, the target material in the vacuum arc ion plating method is an aluminum target and an alloy target containing aluminum and rare earth elements.

[0077] In some embodiments of the present invention, the bias voltage of the magnetron sputtering method during deposition is 50-140V; in some embodiments of the present invention, the bias voltage of the magnetron sputtering method during deposition is any value among 50V, 60V, 70V, 80V, 90V, 100V, 110V, 120V, 130V, 140V, and 150V, or a range formed by any two of them.

[0078] In some embodiments of the present invention, the working gas during the deposition by the magnetron sputtering method is an inert gas.

[0079] In some embodiments of the present invention, the gas flow rate of the magnetron sputtering method during deposition is 140-180sccm; in some embodiments of the present invention, the gas flow rate of the magnetron sputtering method during deposition is any value among 140sccm, 150sccm, 160sccm, 170sccm, 180sccm or a range formed by any two of them.

[0080] In some embodiments of the present invention, the turntable speed of the magnetron sputtering method during deposition is 3 to 10 rpm; in some embodiments of the present invention, the turntable speed of the magnetron sputtering method during deposition can be any one of 3 rpm, 4 rpm, 5 rpm, 6 rpm, 7 rpm, 8 rpm, 9 rpm, 10 rpm or a range formed by any two of them.

[0081] In some embodiments of the present invention, the deposition temperature of the magnetron sputtering method during deposition is 250-350°C; in some embodiments of the present invention, the deposition temperature of the magnetron sputtering method during deposition is any one of 250°C, 260°C, 270°C, 280°C, 290°C, 300°C, 310°C, 320°C, 330°C, 340°C, and 350°C, or a range formed by any two of the values.

[0082] In some embodiments of the present invention, the vacuum degree during the magnetron sputtering method is 3×10 -3 ~8×10 - 3 Pa; In some embodiments of the present invention, the vacuum degree during the magnetron sputtering method deposition may be 3×10 -3 Pa, 4×10 - 3 Pa, 5×10 -3 Pa, 6×10 -3 Pa, 7×10 -3 Pa, 8×10 -3 The range of values ​​formed by any one value of Pa or any two of them.

[0083] In some embodiments of the present invention, the target material in the magnetron sputtering method is an aluminum target and an alloy target containing aluminum and rare earth elements.

[0084] In some embodiments of the present invention, the magnetron sputtering method also requires target refining before deposition.

[0085] In some embodiments of the present invention, the target refining temperature is 300-400°C; in some embodiments of the present invention, the target refining temperature can be any value among 300°C, 310°C, 320°C, 330°C, 340°C, 350°C, 360°C, 370°C, 380°C, 390°C, 400°C or a range formed by any two of them.

[0086] In some embodiments of the present invention, the target refining bias voltage is 400-600V; in some embodiments of the present invention, the target refining bias voltage can be any value among 400V, 410V, 420V, 430V, 440V, 450V, 460V, 470V, 480V, 490V, 500V, 510V, 520V, 530V, 540V, 550V, 560V, 570V, 580V, 590V, 600V or a range value formed by any two of them.

[0087] In some embodiments of the present invention, the target refining magnetic field strength is set to a bias voltage of 7.5 to 8.5 V and a frequency of 8 to 9 Hz. In some embodiments of the present invention, the bias voltage can be selected from any value of 7.5 V, 7.6 V, 7.7 V, 7.8 V, 7.9 V, 8 V, 8.1 V, 8.2 V, 8.3 V, 8.4 V, 8.5 V, or a range formed by any two of them. In some embodiments of the present invention, the frequency can be selected from any value of 8 Hz, 8.1 Hz, 8.2 Hz, 8.3 Hz, 8.4 Hz, 8.5 Hz, 8.6 Hz, 8.7 Hz, 8.8 Hz, 8.9 Hz, 9 Hz, or a range formed by any two of them.

[0088] In some embodiments of the present invention, the vacuum degree of the target is 3×10 -2 ~8×10 -2 Pa; in some embodiments of the present invention, the vacuum degree of the target is 3×10 -2 Pa, 4×10 -2 Pa, 5×10 -2 Pa, 6×10 -2 Pa, 7×10 -2 Pa, 8×10 - 2 The range of values ​​formed by any one value of Pa or any two of them.

[0089] In some embodiments of the present invention, the thermal barrier coating is prepared by at least one of supersonic oxygen fuel spraying (HVOF), atmospheric plasma spraying (APS), low pressure plasma spraying (VPS), electron beam-physical vapor deposition (EB-PVD), and plasma spray-physical vapor deposition (PS-PVD).

[0090] In some embodiments of the present invention, the present invention provides a protective coating, wherein the protective coating contains Al3Zr; the protective coating is prepared by the surface modification method described in the above embodiments.

[0091] In some embodiments of the present invention, the thermal barrier coating is a YSZ thermal barrier coating.

[0092] In some embodiments of the present invention, the YSZ thermal barrier coating includes 5% to 10% by mass of yttrium oxide and 90% to 95% by mass of zirconium oxide.

[0093] In some embodiments of the present invention, the mass percentage of yttrium oxide may be any one of 5%, 6%, 7%, 8%, 9%, 10%, or a range formed by any two of them.

[0094] In some embodiments of the present invention, the mass percentage of zirconium oxide may be any one of 90%, 91%, 92%, 93%, 94%, 95%, or a range formed by any two of them.

[0095] In some embodiments of the present invention, the thickness of the alloy layer is 1 μm to 10 μm. In some embodiments of the present invention, the thickness of the alloy layer can be any value of 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, or a range formed by any two of them.

[0096] In some embodiments of the present invention, the thickness of the aluminum layer is 1 μm to 10 μm. In some embodiments of the present invention, the thickness of the aluminum layer can be any value of 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, or a range formed by any two of them.

[0097] In some embodiments of the present invention, the present invention provides an engine, including turbine blades, on which the above-mentioned protective coating is disposed.

[0098] The specific implementation of the present invention is further described in detail below in conjunction with specific embodiments:

[0099] In the aluminum-cerium alloy targets used in the embodiments and comparative examples of the present invention, the mass percentage of cerium (Ce) is 30%, and the mass percentage of aluminum is 70%; the purity of the pure aluminum target is 99.99%; in the YSZ thermal barrier coating, the mass percentage of yttrium oxide is 5% to 10%, and the mass percentage of zirconium oxide is 90% to 95%.

[0100] Example 1

[0101] This example provides a method for surface modification of a thermal barrier coating, comprising the following steps:

[0102] Step 1: Modified coating magnetron sputtering vacuum coating

[0103] (1) The surface of the YSZ thermal barrier coating (yttria-stabilized zirconia) obtained by plasma physical vapor deposition (PS-PVD) spraying is cleaned. The surface cleaning steps are: brushing with ethanol or acetone, and then drying with nitrogen.

[0104] (2) Install different target materials required for coating in the magnetron sputtering equipment. A pure aluminum target is installed on the A-pillar and an aluminum-cerium alloy target is installed on the C-pillar. Setting parameters: temperature 350°C, vacuum degree 5×10 -2 Pa, start heating, evacuate, pass argon and turn on the bias, set the bias to 500V, adjust the magnetic field strength parameters to 8.0V and 8.3Hz, and start target refining.

[0105] (3) Place the coating sample after surface cleaning in step (1) in the magnetron sputtering equipment, evacuate the equipment, and set the parameters as follows: 300°C, vacuum degree 5×10 -3 Pa, turntable speed 5.0rpm, start heating, vacuum, argon, set the argon flow rate to 160sccm. First, apply bias to the C target (i.e., aluminum-cerium alloy target, cerium (Ce) mass percentage is 30%, aluminum mass percentage is 70%), set the voltage to 70V, and the coating time is 100min.

[0106] (4) Apply a bias point target to target A (i.e., pure aluminum target), set the voltage to 70 V, the turntable speed to 5.0 rpm, the coating time to 300 min, and the other settings to be consistent with step (3).

[0107] (5) After coating is completed, vent the air until the air pressure is balanced, open the cabin door and take out the sample.

[0108] After the YSZ thermal barrier coating is vacuum-coated in step 1, a double-layer coating (i.e., a pure aluminum layer and an aluminum-cerium alloy layer) is formed on the surface of the YSZ thermal barrier coating, i.e., an aluminum-cerium alloy layer is provided on the YSZ thermal barrier coating, and a pure aluminum layer is provided on the aluminum-cerium alloy layer. The thickness of the pure aluminum layer is 10 microns, and the thickness of the aluminum-cerium alloy layer is 3 microns.

[0109] Step 2: Vacuum heat treatment of modified coating

[0110] The sample obtained in step 1 was placed in a vacuum heat treatment furnace and the vacuum degree during the heat treatment process was set to no higher than 2×10 - 2 Pa, set the heat treatment curve: first heat to 500 ℃ and keep warm for 120 min, then heat to 700 ℃ and keep warm for 60 min, and then heat to 900 ℃ and keep warm for 100 min to complete the surface modification of the YSZ thermal barrier coating.

[0111] After the modified coating is processed in step 2, the aluminum-cerium alloy layer and the YSZ thermal barrier coating react in situ during vacuum heat treatment to form an intermediate Al3Zr.

[0112] Comparative Example 1

[0113] This example provides a method for surface modification of a thermal barrier coating, comprising the following steps:

[0114] Step 1: Modified coating magnetron sputtering vacuum coating

[0115] (1) The surface of the YSZ thermal barrier coating obtained by PS-PVD spraying is cleaned. The surface cleaning steps are: brushing with ethanol or acetone, and then blowing dry with nitrogen.

[0116] (2) Install the target material required for coating in the magnetron sputtering equipment, and install the pure aluminum target on the A-pillar. Setting parameters: temperature 350℃, vacuum degree 5×10 -2 Pa, start heating, evacuate, pass argon and turn on the bias, set the bias to 500V, adjust the magnetic field strength parameters to 8.0V and 8.3Hz, and start target refining.

[0117] (3) Place the coating sample after surface cleaning in step (1) in the magnetron sputtering equipment, evacuate the equipment, and set the parameters as follows: 300°C, vacuum degree 5×10 -3 Pa, turntable speed 5.0rpm, start heating, vacuum, pass argon, set the argon flow rate to 160sccm, first apply bias point target to target A, set the voltage to 70V, and the coating time is 100min.

[0118] (4) Apply a bias point target to target A, set the voltage to 70 V, the turntable speed to 5.0 rpm, the coating time to 300 min, and the rest is the same as step (3).

[0119] (5) After coating is completed, vent the air until the air pressure is balanced, open the cabin door and take out the sample.

[0120] After vacuum coating the YSZ thermal barrier coating in step 1, a pure aluminum layer is formed on the surface of the YSZ thermal barrier coating, and the thickness of the pure aluminum layer is 13 microns.

[0121] Step 2: Vacuum heat treatment of modified coating

[0122] The sample obtained in step 1 was placed in a vacuum heat treatment furnace and the vacuum degree during the heat treatment process was set to no higher than 2×10 - 2 Pa; set the heat treatment curve: first heat to 500 ° C and keep warm for 120 min, then heat to 700 ° C and keep warm for 60 min, and then heat to 900 ° C and keep warm for 100 min to complete the surface modification of the YSZ thermal barrier coating.

[0123] Comparative Example 2

[0124] This example provides a method for surface modification of a thermal barrier coating, comprising the following steps:

[0125] Step 1: Modified coating magnetron sputtering vacuum coating

[0126] (1) The surface of the YSZ thermal barrier coating obtained by PS-PVD spraying is cleaned. The surface cleaning steps are: brushing with ethanol or acetone, and then blowing dry with nitrogen.

[0127] (2) Install different target materials required for coating in the magnetron sputtering equipment. A pure aluminum target is installed on the A-pillar and an aluminum-cerium alloy target is installed on the C-pillar. Setting parameters: temperature 350°C, vacuum degree 5×10 -2 Pa, start heating, evacuate, pass argon and turn on the bias, set the bias to 500V, adjust the magnetic field strength parameters to 8.0V and 8.3Hz, and start target refining.

[0128] (3) Place the coating sample after surface cleaning in step (1) in the magnetron sputtering equipment, evacuate the equipment, and set the parameters as follows: 300°C, vacuum degree 5×10 -3 Pa, turntable speed 5.0rpm, start heating, vacuum, pass argon, set the argon flow rate to 160sccm, first apply bias point target to C target, set voltage 70V, and coating time 100min.

[0129] (4) Apply a bias point target to target A, set the voltage to 70 V, the turntable speed to 5.0 rpm, the coating time to 300 min, and the rest is the same as step (3).

[0130] (5) After coating is completed, vent the air until the air pressure is balanced, open the cabin door and take out the sample.

[0131] After the YSZ thermal barrier coating is vacuum-coated in step 1, a double-layer coating (i.e., a pure aluminum layer and an aluminum-cerium alloy layer) is formed on the surface of the YSZ thermal barrier coating, i.e., an aluminum-cerium alloy layer is provided on the YSZ thermal barrier coating, and a pure aluminum layer is provided on the aluminum-cerium alloy layer. The thickness of the pure aluminum layer is 10 microns, and the thickness of the aluminum-cerium alloy layer is 3 microns.

[0132] Step 2: Vacuum heat treatment of modified coating

[0133] The sample obtained in step 1 was placed in a vacuum heat treatment furnace and the vacuum degree during the heat treatment process was set to no higher than 2×10 - 2 Pa; set the heat treatment curve: heat up to 500℃ and keep warm for 120min to complete the surface modification of YSZ thermal barrier coating.

[0134] Performance Testing:

[0135] The surface morphology of the modified coatings obtained after modification by the methods in Example 1 and Comparative Example 1 was tested by scanning electron microscopy. The specific test results are as follows: Figure 1 and Figure 2 As shown. Figure 1 and Figure 2It can be seen that the modification method in Example 1 can make the surface of the YSZ thermal barrier coating completely coated, the surface active sites are sufficient, the in-situ reaction is sufficient, the generated intermediate particle size is uniform, and it is not easy to be corroded by CMAS when used. However, in the modification method of Comparative Example 1, the aluminum-cerium alloy target (that is, the rare earth cerium element is not used) is not used, the surface active sites are insufficient, the in-situ reaction is insufficient, and the generated intermediate particle size is large, which is easily corroded by CMAS when used.

[0136] The XRD spectrum of the modified coating obtained by the modification treatment in Example 1 was tested by an X-ray diffractometer. Figure 3 As shown. Figure 3 It can be seen that Al3Zr intermediates are formed in the modified coating in Example 1, which are coated on the surface of the YSZ material to prevent the YSZ thermal barrier coating from being corroded. The modified coating obtained after the modification treatment using the method in Example 1 was tested under simulated service conditions at 1200°C for 500 hours. The XRD spectrum of the modified coating after service is as follows: Figure 4 As shown. Figure 4 It can be seen that after being kept at 1200℃ for 500 hours, the Al3Zr intermediate reacts in situ on the coating surface to continuously form ZrO2, which improves the service life of the coating and enhances the coating's resistance to CMAS (CaO2, MgO, Al2O3, SiO2) corrosion during service.

[0137] The actual pictures of the modified coating obtained after modification by the methods in Example 1 and Comparative Example 2 are as follows: Figure 5 As shown. Figure 5 It can be seen that the surface modification method in Example 1 has sufficient surface active sites, which can make Al and Zr react fully, thereby generating a large number of Al3Zr intermediates with uniform particle size. However, the surface modification method in Comparative Example 2 cannot make aluminum, cerium and YSZ materials react fully, and large-sized agglomerations appear on the surface of the material, affecting the coating performance.

[0138] The modified coating obtained in Example 1 and the unmodified YSZ thermal barrier coating obtained by PS-PVD spraying were subjected to water cooling thermal shock at 1100°C for 60 times, and then their surface morphologies were observed. Figure 6 As shown. Figure 6 It can be seen that after the modified coating obtained in Example 1 was subjected to water cooling and thermal shock at 1100°C for 60 times, the surface of the modified coating was not damaged, while the surface of the unmodified YSZ thermal barrier coating was obviously damaged after being subjected to water cooling and thermal shock at 1100°C for 60 times.

[0139] The modified coating obtained in Example 1 and the unmodified YSZ thermal barrier coating obtained by PS-PVD spraying were subjected to CMAS corrosion for 20 hours, and the EDS spectrum of the modified coating was tested by an EDS spectrometer. Figure 7 and Figure 8 As shown. Figure 7 and Figure 8 It can be seen that no Ca, Mg, Al, and Si elements were observed in the modified coating obtained in Example 1 of the present invention, indicating that the modified coating was not corroded by CMAS; while a large amount of Ca, Mg, Al, and Si elements appeared in the unmodified YSZ thermal barrier coating, indicating that a large amount of Ca, Mg, Al, and Si elements penetrated into the coating and caused corrosion.

[0140] The bonding strength of the modified coating obtained in Example 1 was measured with reference to the aviation standard HB5476-1991. The bonding strength of the modified coating obtained in Example 1 of the present invention reached 57-62 MPa.

[0141] In summary, the present invention uses different rare earth modified aluminum alloys to construct modified layers with different structures on the surface of the YSZ coating, thereby improving the in-situ reaction activity between the modified layer and the YSZ surface, reducing the interface energy caused by the in-situ reaction, forming a complete coating on the YSZ surface, and significantly improving the coating's resistance to CMAS corrosion. The Al3Zr in the in-situ modified layer constructed by the present invention can generate ZrO2 in situ through surface reactions during the service of the coating, thereby extending the service life of the coating and improving the coating's anti-erosion performance. In addition, the preparation process of the present invention is simple, and different modified layers can be prepared in the same furnace.

[0142] The above is a detailed description of the embodiments of the present invention, but the present invention is not limited to the above embodiments. Various changes can be made within the knowledge of ordinary technicians in the relevant technical field without departing from the purpose of the present invention. In addition, the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

Claims

1. A method for surface modification of a thermal barrier coating, characterized in that: The following steps are involved: An alloy layer and an aluminum layer are sequentially formed on the surface of the thermal barrier coating to obtain a thermal barrier coating containing a modified coating; heat-treating the thermal barrier coating containing the modified coating; The alloy layer contains aluminum and rare earth elements.

2. The surface modification method of thermal barrier coating according to claim 1, characterized in that: The heat treatment step has at least one of the following characteristics: (a1) the heat treatment step is carried out under vacuum; (a2) The temperature of the heat treatment step is 400 to 1100° C.; (a3) The heat treatment step lasts for 4 to 10 hours; (a4) The heat treatment steps are: first, keep the temperature at 400-550°C for 100-150 minutes; then keep the temperature at 600-750°C for 40-80 minutes; and then keep the temperature at 800-1100°C for 80-120 minutes.

3. The surface modification method of thermal barrier coating according to claim 1, characterized in that: The rare earth element is at least one selected from lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium, and yttrium; And / or, the mass percentage of rare earth elements in the alloy layer is 5% to 50%; And / or, the mass percentage of aluminum element in the alloy layer is 50-95%.

4. The surface modification method of thermal barrier coating according to claim 1, characterized in that: The step of sequentially forming an alloy layer and an aluminum layer on the surface of the thermal barrier coating comprises: sequentially depositing an alloy layer and an aluminum layer on the surface of the thermal barrier coating by a vacuum arc ion plating method or a magnetron sputtering method.

5. The surface modification method of thermal barrier coating according to claim 4, characterized in that: The vacuum arc ion plating method has at least one of the following characteristics during deposition: (b1) Bias voltage is 120-140 V; (b2) Current is 60 to 80 A; (b3) The working gas is an inert gas; (b4) gas flow rate is 21 to 28 sccm; Or, the magnetron sputtering method has at least one of the following characteristics during deposition: (c1) bias voltage is 50 to 140 V; (c2) The working gas is an inert gas; (c3) gas flow rate is 140-180 sccm; (c4) The rotating speed of the turntable is 3 to 10 rpm; (c5) the deposition temperature is 250-350°C; (c6) Vacuum degree is 3×10 -3 ~8×10 -3 Pa.

6. The surface modification method of the thermal barrier coating according to claim 4, characterized in that: The magnetron sputtering method also requires target refining before deposition; the target refining step has at least one of the following characteristics: (d1) the target refining temperature is 300-400° C.; (d2) the target refining bias voltage is 400-600V; (d3) The target refining magnetic field strength is set to a bias voltage of 7.5 to 8.5 V and a frequency of 8 to 9 Hz; (d4) The vacuum degree of the target refining is 3×10 -2 ~8×10 -2 Pa.

7. The surface modification method of thermal barrier coating according to claim 1, characterized in that: The thermal barrier coating is a YSZ thermal barrier coating; The YSZ thermal barrier coating comprises 5% to 10% by mass of yttrium oxide and 90% to 95% by mass of zirconium oxide; And / or, the alloy layer and / or the aluminum layer has a thickness of 1 μm to 10 μm.

8. A protective coating, characterized in that: The protective coating contains Al3Zr; the protective coating is obtained by using the surface modification method described in any one of claims 1 to 7.

9. An engine comprising a turbine blade, characterized in that: The protective coating according to claim 8 is provided on the turbine blade.

10. Use of the surface modification method of the thermal barrier coating according to any one of claims 1 to 7 and / or the protective coating according to claim 8 in the fields of aviation, aerospace, national defense weapons and equipment or energy.

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