Nickel-based superalloy epitaxial growth structure based on heat source parameters and control method

Abstract

The invention belongs to the technical field of metal laser additive repair, and relates to a nickel-based superalloy epitaxial growth structure and a control method, the method comprises the following steps: fixing a substrate on a workbench, and obtaining a powder raw material for later use; and in the inert gas atmosphere, the powder raw material and a substrate are subjected to laser cladding forming by controlling the laser power to be 1200-2600 W and the scanning speed to be 0.02-0.1 m / s, and the nickel-based superalloy epitaxial growth structure is regulated and controlled. The nickel-based superalloy epitaxial growth structure is regulated and controlled on the basis of heat source parameters, including but not limited to control over laser power and scanning speed. On the basis that laser cladding forming is guaranteed, large heat source input (large laser power or small scanning speed) is beneficial for increasing the depth of a molten pool, reducing stray crystal nucleation and enabling stray crystal nucleation to be completely remelted, and therefore the epitaxial growth characteristic of a columnar crystal structure is guaranteed.

Description

Technical Field

[0001] The invention belongs to the technical field of metal laser additive repair and relates to a nickel-based high-temperature alloy epitaxial growth structure and a control method. Background Art

[0002] The casting process of nickel-based single-crystal turbine blades is complex and the yield rate is low, which makes them extremely valuable. During service, the blades are subjected to high-cycle fatigue, environmental and thermal stress, and other factors, which will cause wear, cracks, corrosion and other problems. If new blades are used to replace blades with only minor defects, wear or cracks at the tip, it will cause a huge waste of materials. Therefore, it is of great economic significance to develop high-efficiency, high-precision and high-quality repair and remanufacturing technologies to restore the size and performance of damaged blades so that they can continue to have service capabilities. In recent years, with the development of metal additive manufacturing technology, additive repair and remanufacturing technologies represented by laser cladding technology have also flourished and become the main way to repair nickel-based single-crystal turbine blades.

[0003] Laser cladding repair of nickel-based single-crystal turbine blades not only needs to consider restoring the geometric shape of the blades and reducing metallurgical defects in the repair area, but the greater challenge is to maintain the integrity of the single crystal so as to meet the requirements for re-service. Laser cladding technology uses a large spot, high-power laser beam as a heat source. The focused laser beam has high energy, and the thermal gradient in the established molten pool is very high, which helps the epitaxial growth of dendrites during the solidification process. However, the microstructure of nickel-based high-temperature alloys will be affected by factors such as heat source parameters (laser power, scanning speed, spot characteristics), deposition strategy (deposition path, overlap rate, cladding head inclination angle) and material parameters (preheating temperature, powder feeding rate, material composition). Therefore, it is crucial to accurately control the microstructure of nickel-based high-temperature alloys by adjusting the above processes. Summary of the invention

[0004] The purpose of the present invention is to provide a method for controlling the epitaxial growth structure of a nickel-based high-temperature alloy, so as to solve the technical problem in the prior art that laser cladding repair of nickel-based single crystal turbine blades cannot be precisely controlled.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: In a first aspect, the present application discloses a method for controlling the epitaxial growth structure of a nickel-based high-temperature alloy, comprising: Fix the substrate on the workbench and obtain the powder raw materials for use; The powder raw materials and the substrate are placed in an inert gas atmosphere, the laser power is controlled to be 1200-2600 W, and the scanning speed is controlled to be 0.02-0.1 m / s for laser cladding forming to regulate the epitaxial growth structure of the nickel-based high-temperature alloy.

[0006] Preferably, during the laser cladding forming, the powder feeding speed is 2 r / min.

[0007] Preferably, during the laser cladding forming, the overlap rate is 40% to 70%.

[0008] Preferably, when performing laser cladding forming, single-layer reciprocating scanning is used for laser cladding forming.

[0009] Preferably, in the single-layer reciprocating scanning, the scanning direction between the upper and lower cladding layers is 180°.

[0010] Preferably, the substrate is a nickel-based high-temperature alloy single crystal substrate, a cast nickel-based high-temperature alloy material or a forged nickel-based high-temperature alloy material.

[0011] Preferably, before using the substrate, the surface of the substrate is polished with sandpaper until it is flat and smooth, and then cleaned with anhydrous ethanol to remove the oxide layer and oil stains on the surface.

[0012] Preferably, the powder raw material has a particle size of 50 to 150 μm and a regular spherical shape.

[0013] Preferably, before use, the nickel-based high-temperature alloy powder raw material is placed in a vacuum drying oven and kept at 120° C. to remove the crystal water in the powder.

[0014] In a second aspect, the present application discloses a nickel-based high-temperature alloy epitaxial growth structure, which is generated by using any of the control methods described above.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The present invention regulates the epitaxial growth structure of nickel-based high-temperature alloy based on heat source parameters, including but not limited to the control of laser power and scanning speed. When the laser power is increased or the scanning rate is reduced, the temperature gradient of the solidification front of the entire molten pool can be increased, and the formation of impurity crystals can be reduced. At the same time, more energy can be absorbed by the molten pool, more powder and matrix materials are melted, and the depth of the molten pool also increases accordingly. Under the condition of ensuring a certain powder feeding rate, the height of the molten pool hardly changes, so the height ratio of the molten pool depth to the total height of the molten pool is greater than the height ratio of the impurity crystals. At this time, it can be ensured that the impurity crystals are completely remelted, and the continuous epitaxial growth characteristics of columnar crystals can be ensured during the multi-layer laser powder deposition process. Therefore, on the basis of ensuring laser cladding forming, a larger heat source input (larger laser power or smaller scanning speed) is conducive to increasing the depth of the molten pool, reducing the nucleation of impurity crystals and making them completely remelted, thereby ensuring the epitaxial growth characteristics of the columnar crystal structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0017] Figure 1 is a flow chart of the method of the present invention; Figure 2 1 is the single-pass morphology of laser cladding in Example 1 of the present invention; wherein (a) is the single-pass morphology of laser cladding corresponding to a laser power of 1400 W in Example 1 of the present invention; and (b) is the single-pass morphology of laser cladding corresponding to a laser power of 2600 W in Example 1 of the present invention.

[0018] Figure 3 EBSD images of the cladding sample in Example 1 of the present invention; wherein (a) is the EBSD image of the cladding sample corresponding to a laser power of 1400 W in Example 1 of the present invention; and (b) is the EBSD image of the cladding sample corresponding to a laser power of 2600 W in Example 1 of the present invention.

[0019] Figure 4 3 and 4. The figures are single-pass morphology diagrams of laser cladding in Example 2 of the present invention; wherein (a) is the single-pass morphology of laser cladding corresponding to a scanning rate of 0.02 m / s in Example 2 of the present invention; and (b) is the single-pass morphology of laser cladding corresponding to a scanning rate of 0.1 m / s in Example 2 of the present invention.

[0020] Figure 5 EBSD images of the cladding sample of Example 2 of the present invention; (a) is the EBSD image of the cladding sample corresponding to a scanning rate of 0.02 m / s in Example 2 of the present invention; (b) is the EBSD image of the cladding sample corresponding to a scanning rate of 0.1 m / s in Example 2 of the present invention. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0022] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0024] In the description of the embodiments of the present invention, it should be noted that if the terms "upper", "lower", "horizontal", "inner", etc. indicate an orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use, it is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0025] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", which does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0026] In the description of the embodiments of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0027] The present invention is further described in detail below in conjunction with the accompanying drawings: Laser cladding is a process of rapid cooling and heating. The laser heat source acts on the surface of the substrate to form a tiny molten pool. The molten pool dissipates heat through three methods: heat conduction, radiation, and air convection of the substrate material, which promotes directional solidification of the melt. However, at the top of the cladding layer, due to changes in the heat dissipation direction, temperature gradient, and solidification rate, the epitaxially grown structure undergoes a columnar-equiaxed transformation (CET). CET is a change in the dendrite morphology caused by heterogeneous nucleation. The transformation of CET depends on solidification parameters such as the temperature gradient G at the solid-liquid interface of the molten pool and the dendrite growth rate V. The key to maintaining directional growth of the structure lies in controlling G / V <K CET . The temperature field of the molten pool has several important effects on CET. It also determines the geometry of the molten pool and the temperature gradient at the solidification front, thereby affecting the size and distribution of the two key solidification parameters G and V. Under the interaction between the heat source and the material to be melted, the behaviors of heat transfer, mass transfer and melt flow inside the molten pool ultimately determine the temperature distribution of the molten pool, and these molten pool behaviors are closely related to the repair process parameters such as heat source and material. Therefore, the present invention changes the CET phenomenon in the solidification process of nickel-based high-temperature alloys based on heat source parameters (laser power, scanning speed), and then regulates the epitaxial growth structure.

[0028] See also Figure 1 The present application discloses a method for controlling the epitaxial growth structure of a nickel-based high-temperature alloy, which is characterized by comprising: S1: Fix the substrate on the workbench and obtain the powder raw materials for use; S2: The powder raw material and the substrate are placed in an inert gas atmosphere, the laser power is controlled to be 1200-2600 W, and the scanning speed is controlled to be 0.02-0.1 m / s for laser cladding forming to regulate the epitaxial growth structure of the nickel-based high-temperature alloy.

[0029] In some embodiments, during the laser cladding forming, the powder feeding speed is 2 r / min. In some embodiments, during the laser cladding forming, the overlap rate is 40% to 70%.

[0030] Further preferably, when performing the laser cladding forming, single-layer reciprocating scanning is adopted for the laser cladding forming.

[0031] Further preferably, in the single-layer reciprocating scanning, the scanning direction between the upper and lower cladding layers is 180°.

[0032] In some embodiments, the substrate is a nickel-based high-temperature alloy single crystal substrate, a cast nickel-based high-temperature alloy material, or a forged nickel-based high-temperature alloy material.

[0033] In some embodiments, before using the substrate, the surface of the substrate is polished with sandpaper until it is flat and smooth, and then cleaned with anhydrous ethanol to remove the oxide layer and oil stains on the surface.

[0034] In some embodiments, the powder raw material has a particle size of 50 to 150 μm and a regular spherical shape. Before use, the nickel-based high-temperature alloy powder raw material is placed in a vacuum drying oven and kept at 120° C. to remove the crystal water in the powder.

[0035] In some embodiments, the method for controlling the epitaxial growth structure of a nickel-based high-temperature alloy based on heat source parameters of the present invention specifically includes the following steps: Substrate selection and processing: Select cast or forged nickel-based high-temperature alloy materials as substrate materials, or it is better to select nickel-based high-temperature alloy single crystal substrates as substrate materials; use sandpaper to polish the substrate surface to ensure that it is flat and smooth, and use anhydrous ethanol to remove the oxide layer and oil on the substrate surface to prevent other impurities from being introduced during the experiment; fix the substrate on the workbench.

[0036] Selection and processing of powder raw materials: Nickel-based high-temperature alloy powder raw materials can be prepared by gas atomization or plasma rotating electrode method. The powder particle size is 50-150 μm and the shape is a regular sphere. The nickel-based high-temperature alloy powder raw materials are placed in a vacuum drying oven and kept at 120°C for 2 hours to remove the crystal water in the powder. The dried powder raw materials are poured into the powder feeder.

[0037] Laser cladding forming: An ultra-high-speed laser cladding system was selected for cladding forming experiments. The system was equipped with a 6000W fiber laser and a circular spot diameter of 3 mm. Laser cladding was carried out in an argon protective atmosphere. The laser power was 1200-2600 W, the scanning speed was 0.02-0.1 m / s, the powder feeding speed was 2 r / min, the overlap rate was 40%-70%, and a single-layer reciprocating scanning strategy was used. The scanning direction between the upper and lower cladding layers was 180°.

[0038] The present invention regulates the epitaxial growth structure of nickel-based high-temperature alloy based on heat source parameters, including but not limited to the control of laser power and scanning speed. When the laser power is increased or the scanning rate is reduced, the temperature gradient of the solidification front of the entire molten pool can be increased, and the formation of impurity crystals can be reduced. At the same time, more energy can be absorbed by the molten pool, more powder and matrix materials are melted, and the depth of the molten pool also increases accordingly. Under the condition of ensuring a certain powder feeding rate, the height of the molten pool hardly changes, so the height ratio of the molten pool depth to the total height of the molten pool is greater than the height ratio of the impurity crystals. At this time, it can be ensured that the impurity crystals are completely remelted, and the continuous epitaxial growth characteristics of columnar crystals can be ensured during the multi-layer laser powder deposition process. Therefore, on the basis of ensuring laser cladding forming, a larger heat source input (larger laser power or smaller scanning speed) is conducive to increasing the depth of the molten pool, reducing the nucleation of impurity crystals and making them completely remelted, thereby ensuring the epitaxial growth characteristics of the columnar crystal structure.

[0039] Embodiment 1: The cast IN625 nickel-based high-temperature alloy material is selected as the substrate material.

[0040] The substrate surface was polished with sandpaper to ensure that it was flat and smooth, and was cleaned with anhydrous ethanol to remove the oxide layer and oil stains on the substrate surface to prevent other impurities from being introduced during the experiment.

[0041] Secure the base plate to your work surface.

[0042] IN625 nickel-based high-temperature alloy powder prepared by gas atomization method was selected as the raw material for laser cladding. The chemical composition of the powder included, by mass percentage, Cr: 21.62%, Nb: 4.02%, Mo: 9.24%, Ti: 0.14%, Al: 0.23%, Co: 0.08%, Fe: 2.18%, C: 0.005%, O: 0.012%, and the balance was Ni and unavoidable impurities.

[0043] The powder fluidity of IN625 nickel-based high-temperature alloy is 15.4 s / 50g, the powder particle size is 61 μm to 137 μm, and the powder is a regular spherical shape.

[0044] The raw material of IN625 nickel-based high-temperature alloy powder was placed in a vacuum drying oven and kept at 120°C for 2 hours to remove the crystal water in the powder.

[0045] Pour the dried powder raw materials into the powder feeder.

[0046] An ultra-high-speed laser cladding system is selected, and laser cladding forming is carried out in an argon protective atmosphere.

[0047] The laser spot diameter is 3 mm, the scanning speed is 0.05 m / s, the powder feeding speed is 2 r / min, and the overlap rate is 60%.

[0048] Single-pass cladding was performed using low laser power of 1400 W and high laser power of 2600 W. The single-pass morphology is shown in Figure 2. Figure 2 As shown, the corresponding melting depth and melting height of a single pass with low laser power are 99 μm and 151 μm, respectively, and the corresponding melting depth and melting height of a single pass with high laser power are 210 μm and 3961 μm, respectively.

[0049] The low laser power of 1400 W and the high laser power of 2600 W were used for multi-layer and multi-pass cladding. The single-layer reciprocating scanning strategy was adopted, and the scanning direction between the upper and lower cladding layers was 180°. The corresponding EBSD of the laser cladding samples with low laser power and high laser power were as follows: Figure 3As shown in the figure, it can be seen that the low laser power organization is a columnar crystal and a miscellaneous crystal dominated by equiaxed crystals appearing alternately, while the high laser power organization presents a continuous columnar crystal organization with epitaxial growth characteristics. Therefore, the epitaxial growth characteristics of the nickel-based high-temperature alloy organization can be regulated by changing the laser power.

[0050] Embodiment 2: The cast IN718 nickel-based high-temperature alloy material is selected as the substrate material.

[0051] The substrate surface was polished with sandpaper to ensure that it was flat and smooth, and was cleaned with anhydrous ethanol to remove the oxide layer and oil stains on the substrate surface to prevent other impurities from being introduced during the experiment.

[0052] Secure the base plate to your work surface.

[0053] IN718 nickel-based high-temperature alloy powder prepared by a plasma rotating electrode method was selected as the raw material for laser cladding. The chemical composition of the powder included, by mass percentage, Cr: 19.55%, Nb: 5.18%, Mo: 3.05%, Ti: 1.03%, Al: 0.54%, Co: 0.1%, Fe: 18.6%, C: 0.04%, O: 0.005%, and the balance was Ni and unavoidable impurities.

[0054] The powder fluidity of IN718 nickel-based high-temperature alloy is 11.2 s / 50g, the powder particle size is 57 μm to 109 μm, and the powder is a regular spherical shape.

[0055] The raw material of IN718 nickel-based high-temperature alloy powder was placed in a vacuum drying oven and kept at 120°C for 2 hours to remove the crystal water in the powder.

[0056] Pour the dried powder raw materials into the powder feeder.

[0057] An ultra-high-speed laser cladding system is selected, and laser cladding forming is carried out in an argon protective atmosphere.

[0058] The laser spot diameter is 3 mm, the laser power is 2400 W, the powder feeding speed is 2 r / min, and the overlap rate is 60%.

[0059] The single-pass cladding was performed using a small scanning speed of 0.02 m / s and a large scanning speed of 0.1 m / s. The single-pass morphology is shown in Figure 3 As shown, the corresponding melting depth and melting height of a single channel at a low scanning speed are 208 μm and 467 μm, respectively, and the corresponding melting depth and melting height of a single channel at a high scanning speed are 106 μm and 219 μm, respectively.

[0060] The multi-layer and multi-pass cladding was carried out with a small scanning speed of 0.02 m / s and a large scanning speed of 0.1 m / s. The single-layer reciprocating scanning strategy was adopted, and the scanning direction between the upper and lower cladding layers was 180°. The corresponding EBSD of the laser cladding samples with small scanning speed and large scanning speed is as follows Figure 5 As shown in the figure, it can be seen that the structure at a large scanning speed is an alternating appearance of columnar crystals and impurity crystals dominated by equiaxed crystals, while the structure at a small scanning speed presents a continuous columnar crystal structure with epitaxial growth characteristics. Therefore, the epitaxial growth characteristics of the nickel-based high-temperature alloy structure can be regulated by changing the scanning rate.

[0061] Example 3 The cast IN625 nickel-based high-temperature alloy material is selected as the substrate material.

[0062] The substrate surface was polished with sandpaper to ensure that it was flat and smooth, and was cleaned with anhydrous ethanol to remove the oxide layer and oil stains on the substrate surface to prevent other impurities from being introduced during the experiment.

[0063] Secure the base plate to your work surface.

[0064] IN625 nickel-based high-temperature alloy powder prepared by gas atomization method was selected as the raw material for laser cladding. The chemical composition of the powder included, by mass percentage, Cr: 21.62%, Nb: 4.02%, Mo: 9.24%, Ti: 0.14%, Al: 0.23%, Co: 0.08%, Fe: 2.18%, C: 0.005%, O: 0.012%, and the balance was Ni and unavoidable impurities.

[0065] The powder fluidity of IN625 nickel-based high-temperature alloy is 15.4 s / 50g, the powder particle size is 61 μm to 137 μm, and the powder is a regular spherical shape.

[0066] The raw material of IN625 nickel-based high-temperature alloy powder was placed in a vacuum drying oven and kept at 120°C for 2 hours to remove the crystal water in the powder.

[0067] Pour the dried powder raw materials into the powder feeder.

[0068] An ultra-high-speed laser cladding system is selected, and laser cladding forming is carried out in an argon protective atmosphere.

[0069] The laser spot diameter is 3 mm, the scanning speed is 0.03 m / s, the powder feeding speed is 2 r / min, and the overlap rate is 50%.

[0070] Multi-layer and multi-pass cladding was carried out using low laser power of 1300 W and high laser power of 2400 W. A single-layer reciprocating scanning strategy was used, and the scanning direction between the upper and lower cladding layers was 180°. The low laser power structure was columnar crystals and miscellaneous crystals dominated by equiaxed crystals alternating, while the high laser power structure showed a continuous columnar crystal structure with epitaxial growth characteristics. Therefore, the epitaxial growth characteristics of the nickel-based high-temperature alloy structure can be regulated by changing the laser power.

[0071] Example 4 The cast IN625 nickel-based high-temperature alloy material is selected as the substrate material.

[0072] The substrate surface was polished with sandpaper to ensure that it was flat and smooth, and was cleaned with anhydrous ethanol to remove the oxide layer and oil stains on the substrate surface to prevent other impurities from being introduced during the experiment.

[0073] Secure the base plate to your work surface.

[0074] IN625 nickel-based high-temperature alloy powder prepared by gas atomization method was selected as the raw material for laser cladding. The chemical composition of the powder included, by mass percentage, Cr: 21.62%, Nb: 4.02%, Mo: 9.24%, Ti: 0.14%, Al: 0.23%, Co: 0.08%, Fe: 2.18%, C: 0.005%, O: 0.012%, and the balance was Ni and unavoidable impurities.

[0075] The powder fluidity of IN625 nickel-based high-temperature alloy is 15.4 s / 50g, the powder particle size is 61 μm to 137 μm, and the powder is a regular spherical shape.

[0076] The raw material of IN625 nickel-based high-temperature alloy powder was placed in a vacuum drying oven and kept at 120°C for 2 hours to remove the crystal water in the powder.

[0077] Pour the dried powder raw materials into the powder feeder.

[0078] An ultra-high-speed laser cladding system is selected, and laser cladding forming is carried out in an argon protective atmosphere.

[0079] The laser spot diameter is 3 mm, the scanning speed is 0.1 m / s, the powder feeding speed is 2 r / min, and the overlap rate is 70%.

[0080] Multi-layer and multi-pass cladding was carried out with low laser power of 1200 W and high laser power of 2600 W. A single-layer reciprocating scanning strategy was used, and the scanning direction between the upper and lower cladding layers was 180°. The low laser power structure was columnar crystals and miscellaneous crystals dominated by equiaxed crystals alternating, while the high laser power structure showed a continuous columnar crystal structure with epitaxial growth characteristics. Therefore, the epitaxial growth characteristics of the nickel-based high-temperature alloy structure can be regulated by changing the laser power.

[0081] Example 5 The cast IN625 nickel-based high-temperature alloy material is selected as the substrate material.

[0082] The substrate surface was polished with sandpaper to ensure that it was flat and smooth, and was cleaned with anhydrous ethanol to remove the oxide layer and oil stains on the substrate surface to prevent other impurities from being introduced during the experiment.

[0083] Secure the base plate to your work surface.

[0084] IN625 nickel-based high-temperature alloy powder prepared by gas atomization method was selected as the raw material for laser cladding. The chemical composition of the powder included, by mass percentage, Cr: 21.62%, Nb: 4.02%, Mo: 9.24%, Ti: 0.14%, Al: 0.23%, Co: 0.08%, Fe: 2.18%, C: 0.005%, O: 0.012%, and the balance was Ni and unavoidable impurities.

[0085] The powder fluidity of IN625 nickel-based high-temperature alloy is 15.4 s / 50g, the powder particle size is 61 μm to 137 μm, and the powder is a regular spherical shape.

[0086] The raw material of IN625 nickel-based high-temperature alloy powder was placed in a vacuum drying oven and kept at 120°C for 2 hours to remove the crystal water in the powder.

[0087] Pour the dried powder raw materials into the powder feeder.

[0088] An ultra-high-speed laser cladding system is selected, and laser cladding forming is carried out in an argon protective atmosphere.

[0089] The laser spot diameter is 3 mm, the scanning speed is 0.06 m / s, the powder feeding speed is 2 r / min, and the overlap rate is 40%.

[0090] Multi-layer and multi-pass cladding was carried out with low laser power of 1500 W and high laser power of 2300 W. A single-layer reciprocating scanning strategy was used, and the scanning direction between the upper and lower cladding layers was 180°. The low laser power structure was columnar crystals and miscellaneous crystals dominated by equiaxed crystals alternating, while the high laser power structure showed a continuous columnar crystal structure with epitaxial growth characteristics. Therefore, the epitaxial growth characteristics of the nickel-based high-temperature alloy structure can be regulated by changing the laser power.

[0091] Example 6 The cast IN625 nickel-based high-temperature alloy material is selected as the substrate material.

[0092] The substrate surface was polished with sandpaper to ensure that it was flat and smooth, and was cleaned with anhydrous ethanol to remove the oxide layer and oil stains on the substrate surface to prevent other impurities from being introduced during the experiment.

[0093] Secure the base plate to your work surface.

[0094] IN625 nickel-based high-temperature alloy powder prepared by gas atomization method was selected as the raw material for laser cladding. The chemical composition of the powder included, by mass percentage, Cr: 21.62%, Nb: 4.02%, Mo: 9.24%, Ti: 0.14%, Al: 0.23%, Co: 0.08%, Fe: 2.18%, C: 0.005%, O: 0.012%, and the balance was Ni and unavoidable impurities.

[0095] The powder fluidity of IN625 nickel-based high-temperature alloy is 15.4 s / 50g, the powder particle size is 61 μm to 137 μm, and the powder is a regular spherical shape.

[0096] The raw material of IN625 nickel-based high-temperature alloy powder was placed in a vacuum drying oven and kept at 120°C for 2 hours to remove the crystal water in the powder.

[0097] Pour the dried powder raw materials into the powder feeder.

[0098] An ultra-high-speed laser cladding system is selected, and laser cladding forming is carried out in an argon protective atmosphere.

[0099] The laser spot diameter is 3 mm, the scanning speed is 0.06 m / s, the powder feeding speed is 2 r / min, and the overlap rate is 65%.

[0100] Low laser power of 1450 W and high laser power of 2600 W were used for multi-layer and multi-pass cladding. A single-layer reciprocating scanning strategy was used, and the scanning direction between the upper and lower cladding layers was 180°. The low laser power structure was columnar crystals and miscellaneous crystals dominated by equiaxed crystals appearing alternately, while the high laser power structure showed a continuous columnar crystal structure with epitaxial growth characteristics. Therefore, the epitaxial growth characteristics of the nickel-based high-temperature alloy structure can be regulated by changing the laser power.

[0101] Example 7 The cast IN625 nickel-based high-temperature alloy material is selected as the substrate material.

[0102] The substrate surface was polished with sandpaper to ensure that it was flat and smooth, and was cleaned with anhydrous ethanol to remove the oxide layer and oil stains on the substrate surface to prevent other impurities from being introduced during the experiment.

[0103] Secure the base plate to your work surface.

[0104] IN625 nickel-based high-temperature alloy powder prepared by gas atomization method was selected as the raw material for laser cladding. The chemical composition of the powder included, by mass percentage, Cr: 21.62%, Nb: 4.02%, Mo: 9.24%, Ti: 0.14%, Al: 0.23%, Co: 0.08%, Fe: 2.18%, C: 0.005%, O: 0.012%, and the balance was Ni and unavoidable impurities.

[0105] The powder fluidity of IN625 nickel-based high-temperature alloy is 15.4 s / 50g, the powder particle size is 61 μm to 137 μm, and the powder is a regular spherical shape.

[0106] The raw material of IN625 nickel-based high-temperature alloy powder was placed in a vacuum drying oven and kept at 120°C for 2 hours to remove the crystal water in the powder.

[0107] Pour the dried powder raw materials into the powder feeder.

[0108] An ultra-high-speed laser cladding system is selected, and laser cladding forming is carried out in an argon protective atmosphere.

[0109] The laser spot diameter is 3 mm, the scanning speed is 0.06 m / s, the powder feeding speed is 2 r / min, and the overlap rate is 55%.

[0110] Multi-layer and multi-pass cladding was carried out using low laser power of 1250 W and high laser power of 2300 W. A single-layer reciprocating scanning strategy was used, and the scanning direction between the upper and lower cladding layers was 180°. The low laser power structure was columnar crystals and miscellaneous crystals dominated by equiaxed crystals alternating, while the high laser power structure showed a continuous columnar crystal structure with epitaxial growth characteristics. Therefore, the epitaxial growth characteristics of the nickel-based high-temperature alloy structure can be regulated by changing the laser power.

[0111] Example 8 The cast IN625 nickel-based high-temperature alloy material is selected as the substrate material.

[0112] The substrate surface was polished with sandpaper to ensure that it was flat and smooth, and was cleaned with anhydrous ethanol to remove the oxide layer and oil stains on the substrate surface to prevent other impurities from being introduced during the experiment.

[0113] Secure the base plate to your work surface.

[0114] IN625 nickel-based high-temperature alloy powder prepared by gas atomization method was selected as the raw material for laser cladding. The chemical composition of the powder included, by mass percentage, Cr: 21.62%, Nb: 4.02%, Mo: 9.24%, Ti: 0.14%, Al: 0.23%, Co: 0.08%, Fe: 2.18%, C: 0.005%, O: 0.012%, and the balance was Ni and unavoidable impurities.

[0115] The powder fluidity of IN625 nickel-based high-temperature alloy is 15.4 s / 50g, the powder particle size is 61 μm to 137 μm, and the powder is a regular spherical shape.

[0116] The raw material of IN625 nickel-based high-temperature alloy powder was placed in a vacuum drying oven and kept at 120°C for 2 hours to remove the crystal water in the powder.

[0117] Pour the dried powder raw materials into the powder feeder.

[0118] An ultra-high-speed laser cladding system is selected, and laser cladding forming is carried out in an argon protective atmosphere.

[0119] The laser spot diameter is 3 mm, the scanning speed is 0.06 m / s, the powder feeding speed is 2 r / min, and the overlap rate is 55%.

[0120] Multi-layer and multi-pass cladding was carried out using low laser power of 1375 W and high laser power of 2550 W. A single-layer reciprocating scanning strategy was used, and the scanning direction between the upper and lower cladding layers was 180°. The low laser power structure was columnar crystals and miscellaneous crystals dominated by equiaxed crystals alternating, while the high laser power structure showed a continuous columnar crystal structure with epitaxial growth characteristics. Therefore, the epitaxial growth characteristics of the nickel-based high-temperature alloy structure can be regulated by changing the laser power.

[0121] Example 9 The cast IN625 nickel-based high-temperature alloy material is selected as the substrate material.

[0122] The substrate surface was polished with sandpaper to ensure that it was flat and smooth, and was cleaned with anhydrous ethanol to remove the oxide layer and oil stains on the substrate surface to prevent other impurities from being introduced during the experiment.

[0123] Secure the base plate to your work surface.

[0124] IN625 nickel-based high-temperature alloy powder prepared by gas atomization method was selected as the raw material for laser cladding. The chemical composition of the powder included, by mass percentage, Cr: 21.62%, Nb: 4.02%, Mo: 9.24%, Ti: 0.14%, Al: 0.23%, Co: 0.08%, Fe: 2.18%, C: 0.005%, O: 0.012%, and the balance was Ni and unavoidable impurities.

[0125] The powder fluidity of IN625 nickel-based high-temperature alloy is 15.4 s / 50g, the powder particle size is 61 μm to 137 μm, and the powder is a regular spherical shape.

[0126] The raw material of IN625 nickel-based high-temperature alloy powder was placed in a vacuum drying oven and kept at 120°C for 2 hours to remove the crystal water in the powder.

[0127] Pour the dried powder raw materials into the powder feeder.

[0128] An ultra-high-speed laser cladding system is selected, and laser cladding forming is carried out in an argon protective atmosphere.

[0129] The laser spot diameter is 3 mm, the scanning speed is 0.07 m / s, the powder feeding speed is 2 r / min, and the overlap rate is 58%.

[0130] Low laser power of 1425 W and high laser power of 2650 W were used for multi-layer and multi-pass cladding, with a single-layer reciprocating scanning strategy. The scanning direction between the upper and lower cladding layers was 180°. The low laser power structure was columnar crystals and miscellaneous crystals dominated by equiaxed crystals alternating, while the high laser power structure showed a continuous columnar crystal structure with epitaxial growth characteristics. Therefore, the epitaxial growth characteristics of the nickel-based high-temperature alloy structure can be regulated by changing the laser power.

[0131] Example 10 The cast IN625 nickel-based high-temperature alloy material is selected as the substrate material.

[0132] The substrate surface was polished with sandpaper to ensure that it was flat and smooth, and was cleaned with anhydrous ethanol to remove the oxide layer and oil stains on the substrate surface to prevent other impurities from being introduced during the experiment.

[0133] Secure the base plate to your work surface.

[0134] IN625 nickel-based high-temperature alloy powder prepared by gas atomization method was selected as the raw material for laser cladding. The chemical composition of the powder included, by mass percentage, Cr: 21.62%, Nb: 4.02%, Mo: 9.24%, Ti: 0.14%, Al: 0.23%, Co: 0.08%, Fe: 2.18%, C: 0.005%, O: 0.012%, and the balance was Ni and unavoidable impurities.

[0135] The powder fluidity of IN625 nickel-based high-temperature alloy is 15.4 s / 50g, the powder particle size is 61 μm to 137 μm, and the powder is a regular spherical shape.

[0136] The raw material of IN625 nickel-based high-temperature alloy powder was placed in a vacuum drying oven and kept at 120°C for 2 hours to remove the crystal water in the powder.

[0137] Pour the dried powder raw materials into the powder feeder.

[0138] An ultra-high-speed laser cladding system is selected, and laser cladding forming is carried out in an argon protective atmosphere.

[0139] The laser spot diameter is 3 mm, the scanning speed is 0.06 m / s, the powder feeding speed is 2 r / min, and the overlap rate is 40%.

[0140] Low laser power of 1450 W and high laser power of 2550 W were used for multi-layer and multi-pass cladding. A single-layer reciprocating scanning strategy was used, and the scanning direction between the upper and lower cladding layers was 180°. The low laser power structure was columnar crystals and miscellaneous crystals dominated by equiaxed crystals alternating, while the high laser power structure showed a continuous columnar crystal structure with epitaxial growth characteristics. Therefore, the epitaxial growth characteristics of the nickel-based high-temperature alloy structure can be regulated by changing the laser power.

[0141] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for controlling the epitaxial growth structure of a nickel-based high-temperature alloy, characterized in that: include: Fix the substrate on the workbench and obtain the powder raw materials for use; The powder raw materials and the substrate are placed in an inert gas atmosphere, the laser power is controlled to be 1200-2600 W, and the scanning speed is controlled to be 0.02-0.1 m / s for laser cladding forming to regulate the epitaxial growth structure of the nickel-based high-temperature alloy.

2. The method for controlling the epitaxial growth structure of a nickel-based high-temperature alloy according to claim 1, characterized in that: During the laser cladding forming, the powder feeding speed is 2 r / min.

3. The method for controlling the epitaxial growth structure of a nickel-based high-temperature alloy according to claim 1, characterized in that: When the laser cladding forming is performed, the overlap rate is 40% to 70%.

4. The method for controlling the epitaxial growth structure of a nickel-based high-temperature alloy according to claim 1, characterized in that: When the laser cladding forming is performed, single-layer reciprocating scanning is adopted for the laser cladding forming.

5. The method for controlling the epitaxial growth structure of a nickel-based high-temperature alloy according to claim 4, characterized in that: In the single-layer reciprocating scanning, the scanning direction between the upper and lower cladding layers is 180°.

6. The method for controlling the epitaxial growth structure of a nickel-based high-temperature alloy according to claim 1, characterized in that: The substrate is a nickel-based high-temperature alloy single crystal substrate, a cast nickel-based high-temperature alloy material or a forged nickel-based high-temperature alloy material.

7. The method for controlling the epitaxial growth structure of a nickel-based high-temperature alloy according to claim 1, characterized in that: Before using the substrate, the surface of the substrate is polished with sandpaper until it is flat and smooth, and then cleaned with anhydrous ethanol to remove the oxide layer and oil stains on the surface.

8. The method for controlling the epitaxial growth structure of a nickel-based high-temperature alloy according to claim 1, characterized in that: The powder raw material has a particle size of 50 to 150 μm and a regular spherical shape.

9. The method for controlling the epitaxial growth structure of a nickel-based high-temperature alloy according to claim 1, characterized in that: Before use, the nickel-based high-temperature alloy powder raw material is placed in a vacuum drying oven and kept at 120° C. to remove the crystal water in the powder.

10. A nickel-based high-temperature alloy epitaxial growth structure, characterized in that: The generation is regulated by the control method described in any one of claims 1 to 9.

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