A thermal barrier coating based on ultrafast laser-induced interface nucleation and pinning effect and a preparation method thereof

Abstract

The application discloses a thermal barrier coating based on ultrafast laser-induced interface nucleation and pinning effect and a preparation method thereof, which comprises the following steps: preparing an MCrAlYX metal bonding layer on the surface of an alloy base; performing surface scanning treatment on the MCrAlYY metal bonding layer by using an ultrafast laser; and finally preparing a ceramic surface layer on the surface of the MCrAlYX metal bonding layer by using an electron beam physical vapor deposition method. Through the high-density crystal defects and the periodic heat accumulation effect induced by the ultrafast laser at the micro-nano scale, the directional segregation of trace active elements is actively regulated, and the nucleation potential barrier of the EB-PVD gas phase deposition is reduced, so that the periodic anchoring of the composite oxide pin and the significant refinement of the ceramic surface layer structure are realized, and the interface bonding force and the service life of the coating system are improved.

Description

Technical Field

[0001] This invention relates to a thermal barrier coating based on ultrafast laser-induced interface nucleation and pinning effect and its preparation method, belonging to the field of coating technology. Background Technology

[0002] The high-temperature service life of thermal barrier coatings (TBCs) is mainly limited by the interfacial spalling between the metal binder layer and the electron beam physical vapor deposition (EB-PVD) ceramic surface layer. The core cause is the thermal stress mismatch resulting from the thickening of thermally grown oxides (TGOs). To improve interfacial bonding, trace amounts of active elements such as Y, Hf, and Ta are typically added to the MCrAlXY-based binder layer to generate composite oxide nails in situ at high temperatures to anchor the TGO layer. However, under conventional preparation and service conditions, the diffusion and oxidation of active elements are often randomly distributed, making it difficult to control the size and spatial location of the oxide nails. Areas lacking local anchoring are prone to becoming initiation sources of interfacial cracks. In addition, some conventional surface smoothing or densification treatments aimed at improving the oxidation resistance of the binder layer, while delaying TGO growth, result in an overly smooth surface lacking crystal defects, which significantly increases the heterogeneous nucleation barrier for ceramic vapor molecules. The decrease in nucleation density not only weakens the initial physical bonding at the interface, but also changes the competitive mechanism of film growth, leading to coarser columnar crystals in the epitaxially grown ceramic layer, thereby reducing the in-plane strain tolerance and thermal shock resistance of the coating.

[0003] On the other hand, preparing macroscopic geometric structures (such as microgrooves) on surfaces using sandblasting or conventional long-pulse / continuous-wave lasers is another commonly used method for interface roughening and mechanical bonding enhancement. However, conventional laser processing mainly relies on the melting and vaporization of materials, inevitably generating heat-affected zones and residual tensile stresses at the edges of microstructures. These associated defects are highly susceptible to evolving into crack initiation sites in high-temperature environments. Furthermore, the scale mismatch between such macroscopic morphologies on the order of tens to hundreds of micrometers and the atomic-level layer-by-layer deposition characteristics of EB-PVD can easily lead to shadowing effects during deposition, resulting in loose ceramic structures or pores at the bottom of the grooves. Additionally, the prior art, patent application CN202410960291.2 entitled "A Method for Enhancing the Adhesion of Thermal Barrier Ceramic Coatings on Turbine Blades," proposes a method for preparing high-quality microstructures with different patterns on a metal bonding layer using femtosecond lasers to improve the adhesion of thermal barrier ceramic coatings. However, this purely physical macroscopic etching is difficult to intervene in the diffusion dynamics of trace elements within the bonding layer and cannot induce the directional aggregation of active elements, thus making it difficult to achieve synergy between interface morphology and chemical pinning. Existing technologies cannot simultaneously achieve low thermal damage processing, introduction of highly active nucleation sites, and active regulation of trace elements. There is an urgent need to develop a thermal barrier coating preparation method that can synergistically achieve micro-nano scale regulation, reduce the gas phase nucleation barrier, and induce the periodic distribution of oxide nails. Summary of the Invention

[0004] To address the problems of uneven distribution of interfacial oxide pins due to random diffusion of active elements in thermal barrier coatings during high-temperature service, high nucleation barriers in vapor deposition, and coarse columnar crystals in ceramics caused by conventional surface treatment processes, this invention provides a thermal barrier coating based on ultrafast laser-induced interfacial nucleation and pinning effects and its preparation method. By using the high-density crystal defects and periodic thermal accumulation effect induced by ultrafast lasers at the micro-nano scale, the directional agglomeration of trace active elements is actively controlled, reducing the nucleation barrier of EB-PVD vapor deposition. This achieves periodic anchoring of composite oxide pins and significant refinement of the ceramic surface layer structure, synergistically improving the interfacial adhesion and service life of the coating system.

[0005] The specific technical solution adopted in this invention is as follows:

[0006] A thermal barrier coating based on ultrafast laser-induced interface nucleation and pinning effect, the thermal barrier coating includes an alloy substrate and a metal bonding layer, a thermally grown oxide interface layer and a ceramic surface layer attached sequentially from the inside to the outside of the alloy substrate surface; wherein, the alloy used in the metal bonding layer is MCrAlYX, and X is at least one of the elements La, Hf, Ce, Ta, Sc, Dy and Nd.

[0007] The thermally grown oxide interface layer contains periodically distributed composite oxide nails that penetrate the metal bonding layer and interlock with the ceramic surface layer to form a physical anchor. The composite oxide is a composite oxide of Y, Al and X elements.

[0008] The microstructure near the interface of the ceramic surface layer consists of a fine-grained region induced by high-density defects and nucleation growth, with a refined columnar crystal structure above the fine-grained region.

[0009] Preferably, the spatial periodicity of the periodically distributed composite oxide nails matches the periodicity of the ultrafast laser-induced surface micro / nano structure, with a period range of 0.01~0.1 mm, consistent with the laser scanning spacing.

[0010] The above-mentioned method for preparing thermal barrier coatings based on ultrafast laser-induced interface nucleation and pinning effect involves preparing an MCrAlYX metal bonding layer on the surface of an alloy substrate.

[0011] Then, an ultrafast laser is used to perform surface scanning on the MCrAlYX metal bond layer. During this process, the high-frequency pulse thermal accumulation effect of the ultrafast laser drives the Y and X dopants inside the metal bond layer to diffuse and agglomerate uphill to specific periodic micro-nano structures on the surface, inducing the formation of periodic rare earth element micro-nano structures on the surface of the metal bond layer, and inducing the generation of a high-density crystal defect layer containing dislocations, vacancies and grain boundary proliferation on its subsurface.

[0012] Finally, a ceramic surface layer was prepared on the surface of the MCrAlYX metal bonding layer by electron beam physical vapor deposition.

[0013] During ultrafast laser processing and electron beam physical vapor deposition or service, locally segregated Y and X elements form periodically distributed oxide pinning structures at the interface between the metal binder layer and the ceramic surface layer. At the same time, the high-density crystal defect layer serves as a highly active heterogeneous nucleation site, promoting the adsorption and dense nucleation of vapor-phase ceramic molecules on the surface of the metal binder layer.

[0014] Preferably, in the alloy MCrAlYX used for the metal bonding layer, M is Ni and / or Co.

[0015] In the MCrAlYX alloy, the content of Al is 10~15%, the content of Cr is 20~30%, the content of Y is 0.5~1%, the content of X is 0.01~0.5%, and the content of M is the balance. All are mass percentages.

[0016] Preferably, the metal bonding layer is prepared by any one of low-pressure plasma spraying, arc ion plating, or supersonic flame spraying.

[0017] Preferably, the conditions for ultrafast laser processing are: pulse width 200 fs~100 ps, ​​repetition frequency 2~20 MHz, single pulse energy density 0.01~1 J / cm²; scanning speed 10~1000 mm / s, scanning interval 10~100 μm; atmosphere: 99% vol argon and 1% vol oxygen, gas flow 10-20 L / min.

[0018] Preferably, the material used to prepare the ceramic surface layer is at least one of yttrium-stabilized zirconium oxide (7-8% Y2O3-ZrO2) or gadolinium zirconate (Gd2Zr2O7).

[0019] Preferably, the preparation of the ceramic surface layer by electron beam physical vapor deposition includes a pre-oxidation step and a coating deposition step.

[0020] Preferably, the pre-oxidation conditions are: vacuum degree ≤ 5 Pa, rotation speed 10~12 rpm, oxygen flow rate 80~100 sccm, 20~30 min, and preheating temperature 800-1000℃.

[0021] Preferably, the coating deposition conditions are: voltage 15~25 KV, vacuum degree of main processing chamber ≤0.02 Pa, evaporation gun current 0.5~0.9A, preheating gun current 0.1~0.3A, oxygen flow rate 100~200sccm, and deposition rate 2-3μm / min.

[0022] The beneficial effects of this invention are as follows:

[0023] (1) Achieving Directional Segregation and Ultrafine Periodic Anchoring of Multi-Elements: This invention utilizes ultrafast laser scanning with specific parameters and high-frequency pulsed thermal accumulation to drive the oxidation of Y elements and doped X elements (such as Hf, Ta, etc.) to achieve periodic pinning of active elements. Unlike the random oxidation of rare earth elements under traditional processes, this invention, through the synergy of specific pre-oxidation and deposition processes, generates highly regularly arranged composite oxide pins with a spatial size of 0.01~0.1μm in situ at the interface. This structure achieves an extremely uniform physical anchoring effect, effectively eliminating stress concentration and crack initiation caused by the lack of pinning at the interface.

[0024] (2) Constructing high-density crystal defects to significantly reduce the nucleation barrier of vapor deposition: This method introduces a large number of dislocations, vacancies, and grain boundary networks on the subsurface by adjusting the ultrafast laser to a high repetition rate (2~20MHz) and low energy density (0.01~1J / cm²) while avoiding macroscopic thermal damage. These microscopic metallurgical defects provide highly active heterogeneous nucleation sites for subsequent EB-PVD deposition, significantly improving the initial adsorption density of vapor-phase ceramic molecules, thereby strengthening the physical and chemical bonding between the metal binder layer and the ceramic surface layer.

[0025] (3) Optimizing the competitive growth mechanism of the thin film to achieve refined microstructure of the ceramic layer: Benefiting from the dense nucleation sites provided by the high-density crystal defects on the subsurface, the island nucleation density of the EB-PVD ceramic layer increases exponentially in the early stage of growth. The strong competitive growth mechanism of the thin film effectively suppresses the lateral coarsening behavior of single grains, resulting in a significant reduction in the average diameter of columnar crystals in the EB-PVD ceramic layer by 10-50% compared to the coating without ultrafast laser treatment. This refinement of the microstructure effectively improves the strain tolerance and stress coordination ability of the ceramic surface layer, thereby significantly extending the thermal barrier coating's thermal shock fatigue life. Attached Figure Description

[0026] Figure 1 The image shows the SEM morphology of the metal bonding layer surface after step S1 in Example 1.

[0027] Figure 2 The SEM morphology and corresponding energy spectrum of the metal bonding layer surface after ultrafast laser treatment in Example 1 are shown.

[0028] Figure 3 This is a TEM morphology comparison of the metal bonding layer in Example 1 and the metal bonding layer after ultrafast laser treatment;

[0029] Figure 4 The EDS morphology comparison between the thermal barrier coating system of Example 1 and the thermal barrier coating system prepared by introducing ultrafast laser is shown.

[0030] Figure 5Comparison of EBSD morphology between the thermal barrier coating system in Example 1 and the thermal barrier coating system prepared by introducing ultrafast laser;

[0031] Figure 6 The image shows the macroscopic morphology of the comparative thermal barrier coating system in Example 1 after 150 thermal cycles.

[0032] Figure 7 The macroscopic morphology of the thermal barrier coating system prepared by ultrafast laser in Example 1 after 150 thermal cycles;

[0033] Figure 8 The SEM morphology of the metal bonding layer surface after treatment with the ultrafast laser LIPSS method in Comparative Example 1 is shown. Detailed Implementation

[0034] Example 1

[0035] Step S1: Select a 15mm diameter nickel-based superalloy (ReneN5) as the substrate. Use 400# to 1000# silicon carbide sandpaper to progressively polish the substrate to remove surface oxide scale. Then, use 120-mesh corundum at 0.3MPa pressure for surface roughening. After treatment, the substrate is sequentially ultrasonically cleaned in acetone, anhydrous ethanol, and deionized water for 15 minutes each. After cold air drying, it is placed in a vacuum drying oven for later use. The pre-treated substrate is then placed in the vacuum chamber of an arc ion plating (AIP) equipment. A NiCoCrAlYHf alloy (Ni-20Co-28Cr-10Al-0.8Y-0.15Hf, wt.%) is used as the cathode target. The vacuum is evacuated until the base pressure is below 5.0 × 10⁻⁶. -3 After Pa, the substrate was heated to 450℃, and high-purity argon gas was introduced to adjust the working pressure to 1.0 Pa. A negative bias voltage of -800V was applied to the substrate for 10 minutes of argon ion glow discharge cleaning. Subsequently, the working pressure was increased to 0.8 Pa, the bias voltage was reduced to -150V, the arc target power supply was turned on, and the arc current was set to 80A. Continuous deposition was performed for 90 minutes, resulting in a NiCoCrAlYHf metal bond layer with a thickness of approximately 50 μm on the substrate surface. At this point, the coating surface was rough and undulating, exhibiting the large particle morphology inherent in the AIP process. Figure 1 ).

[0036] Step S2: The sample was placed in a 99% vol argon + 1% vol oxygen environment (gas flow rate of 15 L / min). A high-repetition-rate (HRR) full-surface scanning of the metal bonding layer was performed using an ultrafast laser. The laser parameters were set as follows: pulse width 200 fs, repetition rate 10 MHz, single-pulse energy density 0.5 J / cm², scanning speed 50 mm / s, and scanning interval 20 μm. At this point, the surface roughness of the coating was significantly reduced, forming a periodic Y-Al-Hf oxide structure. The corresponding morphology and energy spectrum are shown below. Figure 2 As shown. Furthermore, TEM analysis of the coating revealed that the original AIP metal bond layer surface was dominated by large-sized equiaxed crystals, while after ultrafast laser modification, the surface grains were refined and accompanied by a high-density dislocation structure. Figure 3 ).

[0037] Step S3: After ultrafast laser treatment, the sample is sent to an electron beam physical vapor deposition (EB-PVD) device for pre-oxidation. The vacuum degree of the main processing chamber is controlled at 3 Pa (≤5 Pa), the sample rotation speed is 10 rpm, and 90 sccm of oxygen is introduced. The sample is held at a preheating temperature of 900℃ for 25 min. After pre-oxidation, the YSZ ceramic surface layer deposition stage (raw material is 8% Y2O3-ZrO2) is started. The vacuum degree is adjusted to 0.01 Pa, the oxygen flow rate is increased to 150 sccm, the equipment operating voltage is maintained at 20KV, the evaporation gun current is set to 0.7A, and the preheating gun current is set to 0.2A. A YSZ ceramic layer with a thickness of about 120 μm is continuously prepared at a deposition rate of 2.5 μm / min. After deposition, the sample is cooled to below 300℃ with the furnace to restore atmospheric pressure and then removed.

[0038] In addition, the samples after arc ion plating were directly subjected to electron beam physical vapor deposition of ceramic layers as a control sample.

[0039] like Figure 4 Ultrafast laser treatment followed by electron beam physical vapor deposition resulted in the formation of periodic Y-Al-Hf composite oxide nails at the TGO interface between the metal bond layer and the ceramic surface layer, with spatial dimensions strictly corresponding to the laser scanning interval (approximately 20 μm), achieving extremely uniform physical anchoring. Simultaneously, the bottom of the ceramic surface layer exhibited a dense nucleation and growth of fine-grained regions, with the average diameter of the epitaxially grown YSZ columnar crystals above them significantly reduced compared to the coating without ultrafast laser treatment, resulting in a significantly improved density. Specifically, as shown... Figure 5 As shown.

[0040] Thermal shock cycling tests were conducted after heating to room temperature and water quenching at 1100℃ (holding at 1100℃ for 50 min, followed by cooling to room temperature for 10 min as one cycle). The thermal barrier coating of the untreated control sample showed a peeling rate of 50.68% after 150 thermal cycles. Figure 6 The thermal barrier coating treated with laser had a peeling rate of only 15.74% after 150 thermal cycles. Figure 7 It exhibits excellent interfacial bonding and anti-peeling properties.

[0041] Example 2

[0042] Step S1: Select a 15mm diameter nickel-based superalloy (DD6) as the substrate. Use 400# to 1000# silicon carbide sandpaper to progressively polish the substrate to remove surface oxide scale. Then, use 120-mesh corundum at 0.3MPa pressure for surface roughening. After treatment, the substrate is sequentially ultrasonically cleaned in acetone, anhydrous ethanol, and deionized water for 15 minutes each. After cold air drying, it is placed in a vacuum drying oven for later use. The pretreated substrate is then placed in the vacuum chamber of an arc ion plating (AIP) equipment. A NiCoCrAlYHfTa (Ni-20Co-28Cr-10Al-0.8Y-0.15Hf-0.15Ta, wt.%) alloy is used as the cathode target. The vacuum is evacuated until the base pressure is below 5.0 × 10⁻⁶. -3 After Pa, the substrate was heated to 450℃, and high-purity argon gas was introduced to adjust the working pressure to 1.0 Pa. A negative bias voltage of -800V was applied to the substrate for 10 min of argon ion glow-in-the-light bombardment cleaning. Then, the working pressure was increased to 0.8 Pa, the bias voltage was reduced to -135V, the arc target power supply was turned on and the arc current was set to 79A. Continuous deposition was carried out for 80 min to prepare a NiCoCrAlYHfTa metal bond layer with a thickness of about 45 μm on the substrate surface.

[0043] Step S2: Place the sample in an environment of 99% vol argon + 1% vol oxygen (flow rate of 12 L / min) and use an ultrafast laser to perform full-surface high repetition rate scanning on the metal bonding layer. The laser parameters are set as follows: pulse width 50 ps, ​​repetition frequency 20 MHz, single pulse energy density 0.5 J / cm², scanning speed 40 mm / s, and scanning interval 40 μm.

[0044] Step S3: After laser treatment, the sample is sent to an electron beam physical vapor deposition (EB-PVD) device for pre-oxidation. The vacuum degree of the main processing chamber is controlled at 3 Pa (≤5 Pa), the sample rotation speed is 10 rpm, and 90 sccm of oxygen is introduced. The sample is held at a preheating temperature of 900℃ for 25 min. After pre-oxidation, the Gd2Zr2O7 ceramic surface layer deposition stage is started. The vacuum degree is adjusted to 0.01 Pa, the oxygen flow rate is increased to 150 sccm, the equipment operating voltage is maintained at 20 kV, the evaporation gun current is set to 0.7 A, and the preheating gun current is set to 0.2 A. A Gd2Zr2O7 ceramic layer with a thickness of about 120 μm is continuously prepared at a deposition rate of 2.5 μm / min. After deposition, the sample is cooled to below 300℃ with the furnace to restore atmospheric pressure and then removed.

[0045] In addition, the samples after arc ion plating were directly subjected to electron beam physical vapor deposition of ceramic layers as a control sample.

[0046] Cross-sectional microstructure and energy dispersive spectroscopy characterization confirmed that ultrafast laser treatment followed by electron beam physical vapor deposition resulted in the formation of periodic Y-Al-HfTa composite oxide nails at the TGO interface between the metal binder layer and the ceramic surface layer, with spatial dimensions strictly corresponding to the laser scanning interval (approximately 40 μm), achieving extremely uniform physical anchoring. Simultaneously, the bottom of the ceramic surface layer exhibited a dense nucleation and growth of fine-grained regions, with the average diameter of the epitaxially grown Gd₂Zr₂O₇ columnar crystals significantly reduced compared to the untreated coating, indicating a significant increase in density.

[0047] Thermal shock cycling test (heating from 1100℃ to room temperature and water quenching for 50 min, followed by cooling to room temperature for 10 min as one cycle) showed that the untreated thermal barrier coating had a peeling rate of 55.56% after 150 thermal cycles, while the laser-treated thermal barrier coating had a peeling rate of only 13.28% after 150 thermal cycles, demonstrating excellent interfacial adhesion and anti-peeling performance.

[0048] Comparative Example 1

[0049] Ultrafast laser-induced periodic surface structures (LIPSS), as a conventional surface modification method, can indeed induce periodic ripples or grating structures with nanoscale regularity on the material surface through the interaction between the laser beam and the material surface. To verify the modification effect of Example 1 of this application, this comparative example uses laser parameters for generating typical LIPSS structures for comparative experiments.

[0050] Step S1: Select a 15mm diameter nickel-based superalloy (ReneN5) as the substrate. Use 400# to 1000# silicon carbide sandpaper for progressive polishing to remove surface oxide scale. Then, roughen the surface with 120-mesh corundum at 0.3MPa pressure. After treatment, the substrate is sequentially ultrasonically cleaned in acetone, anhydrous ethanol, and deionized water for 15 minutes each. After cold air drying, it is placed in a vacuum drying oven for later use. The pre-treated substrate is then placed in the vacuum chamber of an arc ion plating (AIP) equipment. A NiCoCrAlYHf alloy (Ni-20Co-28Cr-10Al-0.8Y-0.15Hf, wt.%) is used as the cathode target. The vacuum is evacuated until the base pressure is below 5.0 × 10⁻⁶. -3 After Pa, the substrate was heated to 450°C, and high-purity argon gas was introduced to adjust the working pressure to 1.0 Pa. A negative bias voltage of -800V was applied to the substrate for 10 min of argon ion glow-in-the-light bombardment cleaning. Then, the working pressure was increased to 0.8 Pa, the bias voltage was reduced to -150V, the arc target power supply was turned on and the arc current was set to 80A. Continuous deposition was carried out for 90 min to prepare a NiCoCrAlYHf metal bond layer with a thickness of about 50 μm on the substrate surface. At this time, the coating surface was rough and undulating, with the large particle morphology inherent in the AIP process.

[0051] Step S2: The sample was placed in a 99% vol argon + 1% vol oxygen environment (gas flow rate of 15 L / min), and an ultrafast laser was used to treat the surface of the metal bond layer with laser-induced periodic surface structures (LIPSS). To obtain a typical LIPSS structure, the laser parameters were set near the ablation threshold: pulse width 200 fs, repetition frequency reduced to 100 kHz, single pulse energy density set to 0.08 J / cm², and scanning speed 1 mm / s. After treatment, a subwavelength nano-periodic stripe structure (LIPSS) was indeed formed on the surface of the metal bond layer, such as... Figure 8 As shown. However, due to the extremely low laser energy density and shallow depth of the LIPSS treatment, this method failed to effectively eliminate the large particles remaining from the AIP process and could not effectively reduce the overall surface roughness of the metal bond layer. In addition, TEM analysis showed that this treatment only produced a slight change in physical morphology at the very surface (nanometer depth), and failed to introduce high-density microstructural defects such as dislocations in the subsurface layer as in Example 1. The large-size equiaxed crystal state of the original AIP metal bond layer was not substantially refined, nor was it able to induce deep segregation of active elements.

[0052] Step S3: After ultrafast laser treatment, the sample is sent to an electron beam physical vapor deposition (EB-PVD) device for pre-oxidation and ceramic layer deposition. The parameters are exactly the same as in Example 1: the vacuum degree of the main processing chamber is controlled at 3 Pa (≤5 Pa), the sample rotation speed is 10 rpm, 90 sccm of oxygen is introduced, and the sample is held at a preheating temperature of 900℃ for 25 min. After pre-oxidation, the vacuum degree is adjusted to 0.01 Pa, the oxygen flow rate is increased to 150 sccm, the equipment operating voltage is maintained at 20 kV, the evaporation gun current is 0.7 A, the preheating gun current is 0.2 A, and a YSZ ceramic layer with a thickness of about 120 μm is continuously prepared at a deposition rate of 2.5 μm / min. After deposition, the sample is cooled to below 300℃ with the furnace to restore atmospheric pressure and then removed.

[0053] Cross-sectional microstructure and energy dispersive spectroscopy characterization confirmed that, since LIPSS only formed a shallow nanoscale structure, these nanoscale undulations were rapidly oxidized and smoothed out during subsequent high-temperature pre-oxidation and ceramic layer deposition, failing to achieve effective physical anchoring (no periodic pinning effect) between the metal binder layer and the YSZ ceramic layer. Simultaneously, due to the lack of microscopic lattice defects (such as dislocations) and the absence of changes in local chemical composition, the nucleation barrier during YSZ deposition was not effectively enhanced. Cross-sectional morphology showed that the bottom of the ceramic surface layer lacked a dense, fine-grained nucleation region, and the epitaxially grown YSZ columnar crystals above it exhibited a coarse and loose growth state, with a significantly lower density than in Example 1.

[0054] The same thermal shock cycling test was conducted, from heating at 1100℃ to water quenching at room temperature (holding at 1100℃ for 50 min, followed by cooling at room temperature for 10 min as one cycle). The comparative sample showed a peeling rate of 52.13% after 150 thermal cycles (comparable to or even slightly worse than the 50.68% peeling rate of the baseline sample without any laser treatment). This fully demonstrates that simply relying on the nano-sized LIPSS structure cannot improve the interfacial mechanical interlocking, nor can it optimize the microstructure of the ceramic layer, and ultimately cannot improve the thermal shock cycling performance of the YSZ coating prepared by EB-PVD.

Claims

1. A thermal barrier coating based on ultrafast laser-induced interface nucleation and pinning effect, characterized in that, The thermal barrier coating includes an alloy substrate and a metal bonding layer, a thermally grown oxide interface layer, and a ceramic surface layer, which are sequentially attached to the surface of the alloy substrate from the inside out; wherein, the alloy used in the metal bonding layer is MCrAlYX, and X is at least one of the elements La, Hf, Ce, Ta, Sc, Dy, and Nd. The thermally grown oxide interface layer contains periodically distributed composite oxide nails that penetrate the metal bonding layer and interlock with the ceramic surface layer to form a physical anchor. The composite oxide is a composite oxide of Y, Al and X elements. The microstructure near the interface of the ceramic surface layer consists of a fine-grained region induced by high-density defects and nucleation growth, with a refined columnar crystal structure above the fine-grained region.

2. The method for preparing a thermal barrier coating based on ultrafast laser-induced interface nucleation and pinning effect as described in claim 1, characterized in that, The process involves preparing an MCrAlYX metal bonding layer on the surface of an alloy substrate. The surface of the MCrAlYX metal bonding layer was then scanned using an ultrafast laser, and finally a ceramic surface layer was prepared on the surface of the MCrAlYX metal bonding layer using electron beam physical vapor deposition.

3. The method for preparing a thermal barrier coating based on ultrafast laser-induced interface nucleation and pinning effect according to claim 2, characterized in that, In the alloy MCrAlYX used in the metal bonding layer, M represents Ni and / or Co elements.

4. The method for preparing a thermal barrier coating based on ultrafast laser-induced interface nucleation and pinning effect according to claim 2, characterized in that, The metal bonding layer is prepared by any one of the following processes: low-pressure plasma spraying, electric arc ion plating, or supersonic flame spraying.

5. The method for preparing a thermal barrier coating based on ultrafast laser-induced interface nucleation and pinning effect according to claim 2, characterized in that, The conditions for ultrafast laser processing are: pulse width 200 fs~100 ps, ​​repetition frequency 2~20 MHz, single pulse energy density 0.01~1 J / cm²; scanning speed 10~1000 mm / s, scanning spacing 10~100 μm; Atmosphere: 99% vol argon and 1% vol oxygen, gas flow rate 10-20 L / min.

6. The method for preparing a thermal barrier coating based on ultrafast laser-induced interface nucleation and pinning effect according to claim 2, characterized in that, The material used to prepare the ceramic surface layer is at least one of yttrium-partially stabilized zirconium oxide or gadolinium zirconate.

7. The method for preparing a thermal barrier coating based on ultrafast laser-induced interface nucleation and pinning effect according to claim 2, characterized in that, The preparation of ceramic surface layers by electron beam physical vapor deposition includes pre-oxidation and coating deposition steps.

8. The method for preparing a thermal barrier coating based on ultrafast laser-induced interface nucleation and pinning effect according to claim 7, characterized in that, The pre-oxidation conditions are: vacuum degree ≤ 5Pa, rotation speed 10~12rpm, oxygen flow rate 80~100sccm, 20~30 min, and preheating temperature 800-1000℃.

9. The method for preparing a thermal barrier coating based on ultrafast laser-induced interface nucleation and pinning effect according to claim 7, characterized in that, The coating deposition conditions are as follows: voltage 15~25 KV, vacuum degree of main processing chamber ≤0.02 Pa, evaporation gun current 0.5~0.9A, preheating gun current 0.1~0.3A, oxygen flow rate 100~200sccm, and deposition rate 2-3μm / min.

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