Oscillating laser directed energy deposition of high performance cobalt-based alloy coatings, methods and applications thereof

Abstract

This invention discloses an oscillating laser-directed energy deposition (OLD) high-performance cobalt-based alloy coating, its method, and its application. The OLD high-performance cobalt-based alloy coating comprises multiple cladding layers stacked sequentially. Each cladding layer is formed by multiple layers of cobalt-based alloy deposited sequentially in a direction perpendicular to the stacking direction of the cladding layers. Each layer of cobalt-based alloy consists of a dendritic γ-CoCr phase and intergranular precipitates. The dendritic γ-CoCr phase is the matrix phase, and the intergranular precipitates include a β-NiAl phase and a nano-sized Laves-CoZr2Si4 phase. The β-NiAl phase and the nano-sized Laves-CoZr2Si4 phase are uniformly dispersed in the matrix and do not overlap. The OLD high-performance cobalt-based alloy coating provided by this invention exhibits excellent resistance to high-temperature oxidation, high-temperature wear, hot corrosion, and thermal fatigue.

Description

Technical Field

[0001] This invention relates to the field of surface strengthening technology, and in particular to an oscillating laser directional energy deposition method and application of a high-performance cobalt-based alloy coating. Background Technology

[0002] Directed energy deposition (DED), as an emerging surface modification technology, has shown significant application potential in the preparation of wear-resistant, corrosion-resistant, and thermal barrier coatings. This technology, with its high energy density and high cooling rate, can produce fine-grained and dense cladding coatings. However, high energy input can easily lead to localized overheating, resulting in defects such as thermal deformation, stress concentration, and cracks. To address this issue, oscillating laser-directed energy deposition technology, based on traditional laser cladding, drives the laser to move periodically along a predetermined trajectory by controlling the deflection of optical lenses. Internal galvanometers generate diverse laser oscillation trajectories, achieving active stirring of the molten pool. This process prolongs the bubble escape time within the molten pool, effectively suppressing porosity and crack defects; simultaneously, the laser beam oscillation disrupts the dendritic microstructure, increasing nucleation density and promoting further grain refinement.

[0003] Cobalt-based alloy coatings are renowned for their high strength, high hardness, excellent wear and corrosion resistance, and high-temperature stability. Laminating these coatings onto various substrates can significantly improve the high-temperature resistance, wear resistance, and corrosion resistance of workpieces. However, a key bottleneck exists in the thermally grown oxide (TGO) layer formed during the high-temperature oxidation process of CoNiCrAlY cobalt-based alloy coatings: if the TGO is a dense α-Al₂O₃ film, it can block the diffusion of transition elements and inhibit the formation of harmful oxides, thereby extending the coating's service life; conversely, if the supply of Al ions is insufficient, porous and brittle spinel oxides such as (Ni,Co) and (Cr,Al)₂O₄ are formed, causing the coating to crack and peel off, severely impairing its resistance to high-temperature oxidation. Especially under extreme conditions such as those affecting aero-engine turbine blades, high-speed rotation leading to end-face wear or contact surface wear failure will cause blade dimensions to deviate from the design baseline, reducing engine efficiency and lifespan, and even threatening flight safety. Summary of the Invention

[0004] To synergistically improve the high-temperature oxidation resistance and wear resistance of CoNiCrAlY coatings, this invention provides a high-performance cobalt-based alloy coating with oscillating laser directional energy deposition, its method and application, which has significant engineering implications for extending the service life and improving the reliability of high-temperature components in aerospace, energy and power, and nuclear reactor fields.

[0005] The first objective of this invention is to provide a high-performance cobalt-based alloy coating deposited by oscillating laser directional energy deposition.

[0006] The second objective of this invention is to provide a method for oscillating laser directional energy deposition of high-performance cobalt-based alloy coatings.

[0007] The third objective of this invention is to provide an application method for oscillating laser directional energy deposition of high-performance cobalt-based alloy coatings.

[0008] The first objective of this invention can be achieved by adopting the following technical solution:

[0009] A high-performance cobalt-based alloy coating deposited by oscillating laser directional energy deposition includes multiple cladding layers stacked sequentially. Each cladding layer is formed by multiple cobalt-based alloy layers stacked sequentially in a direction perpendicular to the stacking direction of the cladding layers. Each cobalt-based alloy layer consists of a dendritic γ-CoCr phase and intergranular precipitates. The dendritic γ-CoCr phase is the matrix phase, and the intergranular precipitates include a β-NiAl phase and a nanoscale Laves-CoZr2Si4 phase. The β-NiAl phase and the nanoscale Laves-CoZr2Si4 phase are uniformly dispersed in the matrix and do not overlap.

[0010] Preferably, the volume fraction of the dendritic γ-CoCr phase is 40-60%, and the grain size of the dendritic γ-CoCr phase is 2-5 μm; the volume fraction of the β-NiAl phase is 25-50%, and the grain size of the β-NiAl phase is 0.5-1.5 μm; the volume fraction of the nanoscale Laves-CoZr2Si4 phase is 5-15%, and the grain size of the nanoscale Laves-CoZr2Si4 phase is 20-40 nm.

[0011] Preferably, the nanoscale Laves-CoZr2Si4 phase effectively inhibits the formation of (Ni,Co)Al2O4 spinel oxide and reduces the critical aluminum content for the formation of a single Al2O3 film on the coating surface, making it easier to form a single and dense Al2O3 oxide film. At the same time, the nanoscale Laves-CoZr2Si4 phase is uniformly dispersed in the matrix, playing a dispersion strengthening role, significantly improving dislocation density and grain boundary strength, and further improving the high-temperature oxidation resistance and wear resistance of the cobalt-based alloy coating.

[0012] Preferably, the high-performance cobalt-based alloy coating deposited by oscillating laser-directed energy deposition has a hardness of 750~900 HV and a fracture toughness of 4.7~6.0 MPa·m. 1 / 2 After oxidation at 1100℃ for 100 hours, the weight gain was 0.41~0.68 mg / cm³. 2 The wear rate at room temperature is 0.74 × 10⁻⁶. -7 ~1.36×10 -7 mm 3 / (N·m), the wear rate at 900℃ is 0.27×10 -7 ~0.58×10 -7 mm 3 / (N·m), after hot corrosion at 900℃ for 100h, the weight loss was 2.34~3.78 mg / cm³. 2 After repeated high-temperature thermal fatigue, the coating showed no obvious cracks, only slight oxidation and peeling.

[0013] The second objective of this invention can be achieved by adopting the following technical solution:

[0014] A method for directional energy deposition of a high-performance cobalt-based alloy coating using an oscillating laser, the method comprising:

[0015] S1: To improve the flowability of the alloy powder, ZrSi2-doped CoNiCrAlY alloy powder was dried in a vacuum drying oven; the chemical composition of the ZrSi2-doped CoNiCrAlY alloy powder was: Ni 30-33 wt.%, Cr 22-25 wt.%, Al 3-8 wt.%, Y 0.3-0.7 wt.%, ZrSi 25-15 wt.%, with the balance being Co;

[0016] S2: Place the dried ZrSi2-doped CoNiCrAlY alloy powder into the automatic powder feeder;

[0017] S3: Preheat the substrate to the set temperature after pretreatment;

[0018] S4: Introduce argon gas into the sealed molding chamber to bring the oxygen concentration inside the chamber to the predetermined value.

[0019] S5: Under the action of a laser beam, ZrSi2-doped CoNiCrAlY alloy powder is melted and solidified on the surface of the substrate;

[0020] S6: After a cladding layer is deposited on the substrate surface, return the laser head and powder nozzle to the designated position and increase the slice thickness distance along the Z-axis;

[0021] S7: Repeat steps S5 to S6 until the coating reaches the specified thickness.

[0022] Preferably, the drying temperature is 100℃ and the drying time is 6 hours.

[0023] Preferably, the substrate is an iron alloy or a nickel alloy.

[0024] Preferably, the process parameters set in step S5 are: laser power of 1500~5000W, powder feeding rate of 30~50g / min, scanning speed of 8~15mm / s, overlap rate of 40%~50%, amplitude of 0~5mm, oscillation frequency of 100~1500Hz, and preset trajectory of linear, figure-eight or circular.

[0025] Preferably, in step S5, by adjusting the parameters of the oscillating laser directional energy deposition process, a high cooling rate is generated and ZrSi2 elements are introduced to interact with the cobalt-based alloy, satisfying the formation conditions of the nanoscale Laves-CoZr2Si4 phase, thereby controlling the uniform distribution of the nanoscale structure of the cobalt-based alloy coating.

[0026] The third objective of this invention can be achieved by adopting the following technical solution:

[0027] An application method for oscillating laser directional energy deposition of high-performance cobalt-based alloy coatings, wherein the oscillating laser directional energy deposition of high-performance cobalt-based alloy coatings prepared according to the above method or the above method is applied in the fields of aerospace, energy and power, and high-temperature components of nuclear reactors.

[0028] The present invention has the following advantages over the prior art:

[0029] (1) The oscillating laser directional energy deposition high-performance cobalt-based alloy coating provided by the present invention utilizes the uniformly distributed nanoscale Laves-CoZr2Si4 phase to significantly improve the dislocation density and grain boundary strength of the cobalt-based alloy coating, effectively suppress the formation of spinel oxides such as (Ni,Co)Al2O4 and reduce the critical aluminum content for the formation of a single Al2O3 film on the coating surface, making it easier to generate a single and dense Al2O3 oxide film, and further improving the high-temperature oxidation resistance and wear resistance of the cobalt-based alloy coating.

[0030] (2) The high-performance cobalt-based alloy coating provided by the present invention by oscillating laser directional energy deposition has excellent high-temperature oxidation resistance and wear resistance, with a hardness of 750~900HV and a fracture toughness of 4.7~6.0MPa·m. 1 / 2 After oxidation at 1100℃ for 100 hours, the weight gain was 0.41~0.68 mg / cm³. 2 The wear rate at room temperature is 0.74 × 10⁻⁶. -7 ~1.36×10 -7 mm 3 / (N·m), the wear rate at 900℃ is 0.27×10 -7 ~0.58×10 -7 mm 3 The weight loss (N·m) after hot corrosion at 900℃ (75wt.% Na2SO4 + 25wt.% NaCl) for 100 h was 2.34~3.78 mg / cm³. 2 After repeated high-temperature thermal fatigue, the coating showed no obvious cracks, only slight oxidation and peeling. It can be stably applied in working environments ranging from 800℃ to 1150℃.

[0031] (3) In order to generate uniformly distributed nanoscale Laves-CoZr2Si4 phase in high-performance cobalt-based alloy coatings by oscillating laser-directed energy deposition, this invention innovatively adds ZrSi2 particles to the feedstock and uses oscillating laser-directed energy deposition technology to stir the molten pool, thereby promoting the uniform dispersion of the nanoscale reinforcing phase in the matrix. This composite process significantly enhances the high-temperature stability, hardness, wear resistance, hot corrosion resistance, and thermal cycling fatigue resistance of the coating through composition control and structural optimization. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0033] Figure 1 These are schematic diagrams of the microstructure of the high-performance cobalt-based alloy coatings deposited by oscillating laser directional energy deposition in Examples 1-3 of the present invention. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. It should be understood that the specific embodiments described are merely used to explain this application and are not intended to limit this application.

[0035] In the description of the embodiments of the present invention, the technical terms "upper", "lower", "horizontal", "vertical", etc., indicate the orientation or positional relationship based on the orientation or positional relationship between the components. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of the present invention.

[0036] Example 1:

[0037] The high-performance cobalt-based alloy coating provided in this embodiment by oscillating laser directional energy deposition includes multiple cladding layers stacked sequentially from bottom to top. Each cladding layer is formed by multiple cobalt-based alloy layers stacked sequentially in a direction perpendicular to the stacking direction of the cladding layers. Each cobalt-based alloy layer consists of a dendritic γ-CoCr phase and an intergranular precipitate phase. The dendritic γ-CoCr phase is the matrix phase, and the intergranular precipitate phase includes a β-NiAl phase and a nanoscale Laves-CoZr2Si4 phase. The β-NiAl phase and the nanoscale Laves-CoZr2Si4 phase are uniformly dispersed in the matrix and do not overlap.

[0038] Specifically, the volume fraction of the dendritic γ-CoCr phase is 40-60%, and the grain size is 2-5 μm; the volume fraction of the β-NiAl phase is 25-50%, and the grain size is 0.5-1.5 μm; the volume fraction of the nanoscale Laves-CoZr2Si4 phase is 5-15%, and the grain size is 20-40 nm.

[0039] Specifically, Zr and Si elements capture Co elements to form nanoscale Laves-CoZr2Si4 phase, which effectively inhibits the formation of spinel oxides such as (Ni,Co)Al2O4 and reduces the critical aluminum content for the formation of a single Al2O3 film on the coating surface, making it easier to form a single and dense Al2O3 oxide film. At the same time, the nanoscale Laves-CoZr2Si4 phase is dispersed in the matrix, significantly improving the dislocation density and grain boundary strength, further improving the high-temperature oxidation resistance and wear resistance of the cobalt-based alloy coating.

[0040] The microstructure of the high-performance cobalt-based alloy coating deposited by oscillating laser-directed energy deposition provided in this embodiment can be referenced. Figure 1 Among them, the high-performance cobalt-based alloy coating deposited by oscillating laser-directed energy deposition has a hardness of 750~900 HV and a fracture toughness of 4.7~6.0 MPa·m. 1 / 2 After oxidation at 1100℃ for 100 hours, the weight gain was 0.41~0.68 mg / cm³. 2 The wear rate at room temperature is 0.74 × 10⁻⁶. -7 ~1.36×10 -7 mm 3 / (N·m), the wear rate at 900℃ is 0.27×10 -7 ~0.58×10 -7 mm 3 The weight loss (N·m) after hot corrosion at 900℃ (75wt.% Na2SO4 + 25wt.% NaCl) for 100 h was 2.34~3.78 mg / cm³. 2 After repeated high-temperature thermal fatigue, the coating showed no obvious cracks, only slight oxidation and peeling.

[0041] Example 2:

[0042] The method for directional energy deposition of high-performance cobalt-based alloy coatings using oscillating lasers provided in this embodiment includes the following specific implementation steps:

[0043] S1: To improve the flowability of the alloy powder, the ZrSi2-doped CoNiCrAlY alloy powder was placed in a vacuum drying oven and dried at 100℃ for 6 hours; the chemical composition of the ZrSi2-doped CoNiCrAlY alloy powder was: Ni 31.7wt.%, Cr 22.6wt.%, Al 7.0wt.%, Y 0.5wt.%, ZrSi2 10wt.%, with the balance being Co.

[0044] S2: Place the dried ZrSi2-doped CoNiCrAlY alloy powder into the automatic powder feeder.

[0045] S3: Polish the 316L stainless steel and clean it with ethanol solution to remove the surface oxide film and dirt, and then dry it with cold air.

[0046] S4: Preheat 316L stainless steel to 200℃.

[0047] S5: Introduce argon gas into the sealed molding chamber to make the oxygen concentration inside the chamber 0.05%.

[0048] S6: Draw a CAD 3D model using software, import the model into the processing software, slice the CAD 3D model into layers according to the thickness of the single layer to be deposited, and set the deposition parameters, including laser power, deposition rate, overlap ratio, oscillation parameters, etc.

[0049] The laser power is 1800W, the deposition rate is 7mm / s, the overlap ratio is 50%, the amplitude is 3mm, the oscillation frequency is 150Hz, and the laser beam trajectory is circular. The trajectory function is: x=x0+vt-Acos(ωt), y=y0+Asin(ωt), where x0 is the initial position in the x-direction, v is the deposition rate, t is the time, A is the amplitude, ω=2πf, f is the oscillation frequency, and y0 is the initial position in the y-direction.

[0050] S7: Turn on the powder feeding switch and turn on the laser when the powder flow rate tends to stabilize.

[0051] S8: Under the action of a laser beam, ZrSi2-doped CoNiCrAlY alloy powder is melted and solidified on the surface of the substrate.

[0052] S9: After a coating layer is deposited on the substrate, the laser head and powder nozzle return to the designated position according to the preset values ​​of the CAD model, and rise along the Z-axis to the thickness distance of the slice.

[0053] S10: Repeat steps S8 to S9 until the coating preparation is complete.

[0054] The microstructure of the high-performance cobalt-based alloy coating prepared by oscillating laser-directed energy deposition in this embodiment can be referenced. Figure 1 In this embodiment, using the above-mentioned process parameters, the grain size of the dendritic γ-CoCr phase in the prepared cobalt-based alloy coating is 2.4 μm, the grain size of the β-NiAl phase is 0.8 μm, and the grain size of the nanoscale Laves-CoZr2Si4 phase is 34 nm. The alloy coating achieves a density of 98.5% and a Vickers hardness of 748 HV, representing a three-fold increase in hardness. After oxidation at 1100℃ for 100 h, the weight gain is 0.53 mg / cm³. 2 The wear rate at room temperature is 0.82 × 10⁻⁶. -7 mm 3 / (N·m), compared to traditional cobalt-based alloy coatings, the oxidation weight gain and room temperature wear rate are 90% and 87% lower, respectively.

[0055] Example 3:

[0056] The method for directional energy deposition of high-performance cobalt-based alloy coatings using oscillating lasers provided in this embodiment includes the following specific implementation steps:

[0057] S1: To improve the flowability of the alloy powder, the ZrSi2-doped CoNiCrAlY alloy powder was placed in a vacuum drying oven and dried at 100℃ for 6 hours; the chemical composition of the ZrSi2-doped CoNiCrAlY alloy powder was: Ni 30.7wt.%, Cr 21.6wt.%, Al 6.0wt.%, Y 0.5wt.%, ZrSi2 15wt.%, with the balance being Co.

[0058] S2: Place the dried ZrSi2-doped CoNiCrAlY alloy powder into the automatic powder feeder.

[0059] S3: Polish the Inconel 718 alloy and clean it with ethanol solution to remove the surface oxide film and dirt, and then dry it with cold air.

[0060] S4: Preheat the Inconel 718 alloy to 200°C.

[0061] S5: Introduce argon gas into the sealed molding chamber to make the oxygen concentration inside the chamber 0.05%.

[0062] S6: Draw a CAD 3D model using software, import the model into the processing software, slice the CAD 3D model into layers according to the thickness of the single layer to be deposited, and set the deposition parameters, including laser power, deposition rate, overlap ratio, oscillation parameters, etc.

[0063] The laser power is 2000W, the deposition rate is 10mm / s, the overlap rate is 40%, the amplitude is 2mm, the oscillation frequency is 200Hz, and the laser beam trajectory is a figure-eight shape: the trajectory function is x=x0+vt-Asin(2ωt), y=y0+Asin(ωt).

[0064] S7: Turn on the powder feeding switch and turn on the laser when the powder flow rate tends to stabilize. Under the action of the laser beam, the ZrSi2 doped CoNiCrAlY alloy powder melts and solidifies on the surface of the substrate.

[0065] S8: After a coating layer is deposited on the substrate, the laser head and powder nozzle return to the designated position according to the preset values ​​of the CAD model, and rise along the Z-axis to the thickness distance of the slice.

[0066] S9: Repeat steps S7 to S8 until the coating preparation is complete.

[0067] The microstructure of the high-performance cobalt-based alloy coating prepared by oscillating laser-directed energy deposition in this embodiment can be referenced. Figure 1 In this embodiment, using the above-mentioned process parameters, the cobalt-based alloy coating prepared has a dendritic γ-CoCr grain size of 2.8 μm, a β-NiAl grain size of 1.2 μm, and a nanoscale Laves-CoZr2Si4 phase grain size of 26 nm. The alloy coating achieves a density of 99.5% and a Vickers hardness of 861 HV, representing a 3.5-fold increase in hardness. After oxidation at 1100℃ for 100 h, the weight gain is 0.47 mg / cm³. 2 The wear rate at room temperature is 0.74 × 10⁻⁶. -7 mm 3 / (N·m), compared to traditional cobalt-based alloy coatings, the oxidation weight gain and room temperature wear rate are 93% and 92% lower, respectively.

[0068] Examples 2 and 3 obtained CoNiCrAlY coatings with different high performances by changing the chemical composition of the CoNiCrAlY alloy powder and the printing process parameters. It is understood that more CoNiCrAlY coatings with different high performances can be obtained through more examples (different chemical compositions of CoNiCrAlY high-temperature alloy powders, different amounts of ZrSi2 alloy powder added, and different laser oscillation process parameters), therefore, they will not be listed individually. By precisely controlling the laser trajectory and parameters using oscillating laser-directed energy deposition (OL-DED) technology, dendrites in the microstructure are broken, forming dendritic γ-CoCr phase, β-NiAl phase, and nanoscale Laves-CoZr2Si4 phase. The nanoscale Laves-CoZr2Si4 phase is uniformly dispersed in the matrix, effectively improving the dislocation density and grain boundary strength of the alloy coating and reducing the critical content for the formation of a single Al2O3 film. At the same time, the nanoscale Laves-CoZr2Si4 phase decomposes into ZrO2 and SiO2 in the early stage of oxidation, effectively healing cracks. This alloy coating has excellent high-temperature stability, high hardness and wear resistance, and good thermal fatigue resistance, and can be stably applied in working environments of 800~1150℃.

[0069] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope disclosed in the present invention, based on the technical solution and inventive concept of the present invention, shall fall within the scope of protection of the present invention.

Claims

1. A high-performance cobalt-based alloy coating deposited by oscillating laser directional energy deposition, characterized in that, It includes multiple cladding layers stacked sequentially. Each cladding layer is composed of multiple cobalt-based alloys stacked sequentially in a direction perpendicular to the stacking direction of the cladding layers. Each cobalt-based alloy consists of a dendritic γ-CoCr phase and intergranular precipitates. The dendritic γ-CoCr phase is the matrix phase, and the intergranular precipitates include β-NiAl phase and nanoscale Laves-CoZr2Si4 phase. The β-NiAl phase and nanoscale Laves-CoZr2Si4 phase are uniformly dispersed in the matrix and do not overlap.

2. The high-performance cobalt-based alloy coating deposited by oscillating laser directional energy deposition according to claim 1, characterized in that, The volume fraction of the dendritic γ-CoCr phase is 40-60%, and the grain size of the dendritic γ-CoCr phase is 2-5 μm; the volume fraction of the β-NiAl phase is 25-50%, and the grain size of the β-NiAl phase is 0.5-1.5 μm; the volume fraction of the nanoscale Laves-CoZr2Si4 phase is 5-15%, and the grain size of the nanoscale Laves-CoZr2Si4 phase is 20-40 nm.

3. The high-performance cobalt-based alloy coating deposited by oscillating laser directional energy deposition according to claim 1, characterized in that, The nanoscale Laves-CoZr2Si4 phase effectively inhibits the formation of (Ni,Co)Al2O4 spinel oxide and reduces the critical aluminum content for the formation of a single Al2O3 film on the coating surface, making it easier to form a single and dense Al2O3 oxide film. At the same time, the nanoscale Laves-CoZr2Si4 phase is uniformly dispersed in the matrix, playing a dispersion strengthening role, significantly improving dislocation density and grain boundary strength, and further improving the high-temperature oxidation resistance and wear resistance of the cobalt-based alloy coating.

4. The high-performance cobalt-based alloy coating deposited by oscillating laser directional energy deposition according to any one of claims 1 to 3, characterized in that, The high-performance cobalt-based alloy coating deposited by oscillating laser-directed energy deposition has a hardness of 750~900 HV and a fracture toughness of 4.7~6.0 MPa·m. 1 / 2 After oxidation at 1100℃ for 100 hours, the weight gain was 0.41~0.68 mg / cm³. 2 The wear rate at room temperature is 0.74 × 10⁻⁶. -7 ~1.36×10 -7 mm 3 / (N·m), the wear rate at 900℃ is 0.27×10 -7 ~0.58×10 -7 mm 3 / (N·m), after hot corrosion at 900℃ for 100h, the weight loss was 2.34~3.78 mg / cm³. 2 After repeated high-temperature thermal fatigue, the coating showed no obvious cracks, only slight oxidation and peeling.

5. A method for directional energy deposition of a high-performance cobalt-based alloy coating using an oscillating laser, characterized in that, The method includes: S1: To improve the flowability of the alloy powder, ZrSi2-doped CoNiCrAlY alloy powder was dried in a vacuum drying oven; the chemical composition of the ZrSi2-doped CoNiCrAlY alloy powder was: Ni 30-33 wt.%, Cr 22-25 wt.%, Al 3-8 wt.%, Y 0.3-0.7 wt.%, ZrSi 25-15 wt.%, with the balance being Co; S2: Place the dried ZrSi2-doped CoNiCrAlY alloy powder into the automatic powder feeder; S3: Preheat the substrate to the set temperature after pretreatment; S4: Introduce argon gas into the sealed molding chamber to bring the oxygen concentration inside the chamber to the predetermined value. S5: Under the action of a laser beam, ZrSi2-doped CoNiCrAlY alloy powder is melted and solidified on the surface of the substrate; S6: After a cladding layer is deposited on the substrate surface, return the laser head and powder nozzle to the designated position and increase the slice thickness distance along the Z-axis; S7: Repeat steps S5 to S6 until the coating reaches the specified thickness.

6. The method according to claim 5, characterized in that, The drying temperature is 100℃ and the drying time is 6 hours.

7. The method according to claim 5, characterized in that, The substrate is an iron alloy or a nickel alloy.

8. The method according to claim 5, characterized in that, The process parameters set in step S5 are as follows: laser power is 1500~5000W, powder feeding rate is 30~50g / min, scanning speed is 8~15mm / s, overlap rate is 40%~50%, amplitude is 0~5mm, oscillation frequency is 100~1500Hz, and the preset trajectory is a straight line, a figure-eight shape, or a circle.

9. The method according to any one of claims 5 to 8, characterized in that, In step S5, by adjusting the parameters of the oscillating laser directional energy deposition process, a high cooling rate is generated and ZrSi2 element is introduced to interact with the cobalt-based alloy, satisfying the formation conditions of the nanoscale Laves-CoZr2Si4 phase, thereby controlling the uniform distribution of the nanoscale structure of the cobalt-based alloy coating.

10. A method for applying a high-performance cobalt-based alloy coating by oscillating laser directional energy deposition, characterized in that, Applications of the oscillating laser directional energy deposition high-performance cobalt-based alloy coating according to any one of claims 1 to 4, or the oscillating laser directional energy deposition high-performance cobalt-based alloy coating prepared by the method according to any one of claims 5 to 9, in the fields of aerospace, energy and power, and high-temperature components of nuclear reactors.

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