Laser cladding repair material with high bonding strength and low oxygen-conducting chromatic aberration and method
By using laser cladding materials with low silicon content and ultra-low oxygen environment processes, the problems of conductivity, color difference, bonding strength and oxidation defects of aero-engine controller structural components have been solved, achieving a highly efficient repair effect.
Patent Information
- Application Number
- CN202511845142.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-09
- Publication Date
- 2026-03-03
AI Technical Summary
Existing laser cladding technology has problems when repairing structural components of aero-engine controllers, such as difficulty in simultaneously meeting conductivity and color difference requirements, insufficient bonding strength, and difficulty in controlling oxidation defects.
The laser cladding repair material with low silicon content (Mg 4.5%-6%, Zn 0.2%-0.4%, Si 0.3%-0.8%, RE 0.2%-0.6%, Fe≤0.2%, Cu≤0.1%, balance Al) and the laser cladding process in an ultra-low oxygen environment are used to ensure high conductivity, low color difference and high bonding strength between the repair area and the substrate.
It achieves a low color difference appearance between the repaired area and the substrate, a density of over 96%, and a bonding strength that reaches over 80% of the standard of the parent material, making it suitable for high-strength connections in aero-engine controllers.
Smart Images
Figure CN121592914A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of remanufacturing technology for key components of aero-engines, specifically relating to a laser cladding repair material and method with high bonding strength and low oxygen conductivity color difference. Background Technology
[0002] Aero-engine controller structural components are typically manufactured using high-strength aluminum alloys to ensure lightweight design, good electrical conductivity, and electromagnetic shielding performance. Under prolonged high-temperature and vibration conditions, critical areas such as mating surfaces, threaded holes, and cooling fins are prone to wear, thread damage, and even breakage. Since controllers are high-value, life-cycle-dependent products, direct replacement is extremely costly; therefore, the need for repair and remanufacturing is urgent.
[0003] Repairing such structural components using laser cladding technology faces the following challenges: 1. Conductivity and Color Difference Requirements: Controller structural components have strict requirements for electrical conductivity to ensure the reliability of electrical connections and electromagnetic compatibility. Traditional Al-Si cladding materials (such as AlSi10Mg) have a high Si content (typically greater than 9.5%), which significantly reduces conductivity. Furthermore, after subsequent conductive oxidation treatment, the repaired area appears deep black, creating a severe color difference with the golden yellow of the substrate. This not only affects the appearance but may also impact the overall corrosion resistance of the structural component due to compositional differences.
[0004] 2. Bonding strength and density requirements: The controller structural components often operate under low air pressure and high frequency vibration conditions. Therefore, the repair layer must have high bonding strength and density to prevent the repair layer from peeling off from the substrate under high vibration and forming crack channels through pores. Otherwise, serious safety accidents will occur.
[0005] 3. Oxidation control requirements: Al2O3 oxide film is easily generated during the aluminum alloy cladding process, which is the main reason for the poor bonding strength and porosity of laser cladding. For products operating under extreme conditions, such defects should be minimized. Summary of the Invention
[0006] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a laser cladding repair material and method with high bonding strength and low oxygen conductivity color difference. The laser cladding repair material and method of this invention are designed for the special working conditions of aluminum alloy structural components of aero-engine controllers. They ensure that the repaired area has high conductivity, high bonding strength, and low defect rate that matches the substrate, and achieves low color difference after surface treatment, thus meeting the performance and appearance requirements of aero-engine controller structural components.
[0007] To achieve the above technical objectives, the technical solution adopted in the embodiments of the present invention is as follows: In a first aspect, embodiments of the present invention provide a laser cladding repair material with high bonding strength and low oxygen conductivity color difference, comprising the following components by mass percentage: Mg 4.5%-6%, Zn 0.2%-0.4%, Si 0.3%-0.8%, RE 0.2%-0.6%, Fe≤0.2%, Cu≤0.1%, with the balance being Al; The RE is a mixture of rare earth elements Y and Er, wherein the mass ratio of Y to Er is 1:1.5; The particle size of the laser cladding repair material is 100-150 μm.
[0008] Secondly, embodiments of the present invention provide a laser cladding repair method with high bonding strength and low oxygen conductivity color difference, comprising the following steps: Step S1, Pre-treatment: Pre-treatment is performed on the area of the structural component to be repaired; Step S2: Laser cladding repair is performed using the laser cladding repair material described in claim 1 in an ultra-low oxygen environment; Step S3: After the repaired structural component is cooled to room temperature in the environmental chamber, it is taken out, the cladding area of the structural component is precision machined, and the entire structural component is subjected to conductive oxidation treatment.
[0009] Furthermore, the pretreatment in step S1 includes the following steps: the area to be repaired of the structural component is thoroughly cleaned using an electric wire brush grinder to remove impurities and oxide film, then placed in anhydrous ethanol for ultrasonic cleaning, and kept at 70±10℃ in a vacuum oven for 2-4 hours.
[0010] Furthermore, in step S3, during precision machining, CNC high-precision numerical control machining is used to restore the original dimensions and tolerances of the structural parts.
[0011] Furthermore, in step S1, the material of the structural component to be repaired is 5-series aluminum alloy.
[0012] Furthermore, in step S2, the laser cladding repair includes the following steps: (1) High-purity argon gas is injected into the environmental chamber to make the oxygen content in the environmental chamber less than 100ppm, and the structural component to be repaired is transported to the workbench through the air curtain; (2) The structural component to be repaired is preheated in the environmental chamber, and the preheating temperature is controlled at 150-200℃; (3) A high-precision coaxial powder feeding system is used to deliver the laser cladding repair material to the area to be repaired of the structural component to be repaired for laser cladding repair, and the protective gas is high-purity argon; (4) Control the height of each cladding layer to be 0.3-0.5 mm until the bottom surface to be repaired is completely covered by the cladding layer to complete one layer of repair. Control the temperature of the cladding layer to be 150±20℃ for the next layer of cladding, and so on, until the height of the cladding layer is higher than the surface of the substrate after the cladding is completed.
[0013] Further, in step (3), the parameters of the laser cladding repair are as follows: laser power 2000-2500W, spot diameter 1.6-2.2mm, scanning speed 10-18mm / s, powder feeding amount 0.8-1.6g / min, overlap rate 50%-60%, protective gas flow rate 20-25L / min, and powder feeding gas flow rate 5-10L / min.
[0014] Furthermore, in steps (1) and (3), the purity of the high-purity argon gas is ≥99.99%.
[0015] The beneficial effects of the technical solution provided by the embodiments of the present invention are as follows: 1. Low color difference appearance By formulating a special powder with a composition close to that of the base material, its low Si content design ensures that when the structural component is conductively oxidized after repair, the difference in composition and structure between the repaired area and the base material is small, achieving a low color difference appearance repair. After conductive oxidation, the color difference value ΔE between the base material and the repaired area can be controlled within 1.5, meeting the stringent appearance requirements of aero-engine controller structural components.
[0016] 2. High bonding strength and density The ultra-low oxygen environment process greatly suppresses the oxide film and reduces the porosity in the repair area. After adding rare earth elements, their deoxidation and metamorphic treatment effects further purify the molten pool and refine the grains. The density of the repair layer can reach more than 96%, without defects such as pores and cracks. The bonding strength can reach more than 80% of the lower limit of the standard tensile strength of the base material, achieving a high-strength connection.
[0017] 3. Stable and reliable process The repair process utilizes a fully controllable ultra-low oxygen environment, precise robot control, and excellent thermal management technology to avoid secondary oxidation and thermal stress concentration during the repair process. It is particularly suitable for the thin-walled and complex structural features of aero-engine controller components, enabling precision repair. Attached Figure Description
[0018] Figure 1 This is a schematic flowchart of the laser cladding repair method in an embodiment of the present invention.
[0019] Figure 2 This is a morphological image of the specimen after repair in Example 1.
[0020] Figure 3aThe image shows the metallographic structure of the repaired specimen at 100 μm in Example 1.
[0021] Figure 3b The image shows the metallographic structure of the repaired specimen at 50 μm in Example 1.
[0022] Figure 3c The image shows the metallographic structure of the repaired specimen at 25 μm in Example 1.
[0023] Figure 4 This is a topographical view of the structural component to be repaired in Example 2.
[0024] Figure 5 This is a topographical image of the structural component repaired by laser cladding and then subjected to conductive oxidation in Example 2.
[0025] Figure 6a The image shows the metallographic structure of the repaired structural component in Example 2 at 100 μm.
[0026] Figure 6b The image shows the metallographic structure of the repaired structural component at 50 μm in Example 2.
[0027] Figure 6c The image shows the metallographic structure of the repaired structural component at 25 μm in Example 2.
[0028] Figure labeling: 1 - Boundary line of each cladding layer. Detailed Implementation
[0029] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "inner" and "outer", "upper" and "lower", "left" and "right" is usually based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms 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, and therefore should not be construed as a limitation on the scope of protection of this invention.
[0030] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.
[0031] Example 1 A high-bonding-strength, low-oxygen-conductivity color difference laser cladding repair material comprises the following components by mass percentage: Mg 4.5%, Zn 0.2%, Si 0.4%, RE 0.25%, Fe 0.2%, Cu 0.05%, with the balance being Al. The particle size of the laser cladding repair material is 100-150 μm.
[0032] RE is a mixture of rare earth elements Y and Er, with a mass ratio of Y to Er of 1:1.5, i.e., Y 0.1% and Er 0.15%.
[0033] like Figure 1 As shown, a laser cladding repair method with high bonding strength and low oxygen conductivity color difference includes the following steps: Step S1, Pre-treatment: Use an electric wire brush grinder to deeply clean the area of the structural component to be repaired, remove impurities and oxide film, put it in anhydrous ethanol for ultrasonic cleaning, and keep it at 70°C for 3 hours in a vacuum oven.
[0034] The structural component to be repaired is a U-shaped groove test piece made of 5083 aluminum alloy. The groove is 2mm deep, 8mm wide at the bottom, and has a bevel angle of 45°.
[0035] Step S2, Laser Cladding Repair (1) High-purity argon gas (purity ≥ 99.99%) is injected into the environmental chamber to make the oxygen content in the environmental chamber less than 100ppm. The structural parts to be repaired are transported to the workbench through the air curtain. (2) The structural component to be repaired is preheated in the environmental chamber, and the preheating temperature is controlled at 170°C; (3) A high-precision coaxial powder feeding system is used to transport the above-mentioned laser cladding repair material to the repair area of the structural component to be repaired for laser cladding repair. For the powder feeder, the powder feeding accuracy must be less than 1%, and the protective gas is high-purity argon with a purity of ≥99.99%.
[0036] The parameters for laser cladding repair are as follows: the laser is an IPG fiber laser with a laser power of 2000W, a spot diameter of 1.6 mm, a scanning speed of 12 mm / s, a powder feed rate of 0.9 g / min, an overlap rate of 50%, a protective gas flow rate of 25 L / min, and a powder feed gas flow rate of 5 L / min.
[0037] (4) Control the height of each cladding layer to 0.4 mm until the bottom surface to be repaired is completely covered by the cladding layer to complete one layer of repair. Control the temperature of the cladding layer to 130℃ for the next layer of cladding, and so on, until the height of the cladding layer is higher than the surface of the substrate after the cladding is completed.
[0038] Step S3: After the repaired structural component has cooled to room temperature in the environmental chamber, it is removed. The cladding area of the structural component is then precision machined. Referring to the drawings, high-precision CNC machining is used to restore the original dimensions and tolerances of the structural component. Finally, the entire structural component undergoes conductive oxidation treatment to obtain the desired result. Figure 2 The structural component shown demonstrates that the repaired component has a smooth surface with no obvious defects. The metallographic structure of the repaired component is shown below. Figure 3a ,3b As shown in Figure 3c, it can be seen that the cladding layer is free of defects such as pores and cracks, and the bonding between the cladding layers is relatively dense, which can achieve a high-strength connection between the layers.
[0039] The repair layer was placed at the center of the tensile specimen for sampling and tensile testing. The tensile strength after repair was 223 MPa, which exceeded 80% of the lower limit of the standard tensile strength of the base material.
[0040] The color difference between the cladding repair area and the base material area after conductive oxidation was measured using a colorimeter. A total of 5 test pieces were measured, and 3 color difference values were randomly measured for each test piece. The measurement results are shown in Table 1.
[0041] Table 1
[0042] As can be seen from Table 1, the average color difference value of the five repaired specimens in Example 1 is less than 1.5. This indicates that the composition and structure of the repaired area of the specimen in Example 1 are relatively similar to those of the substrate, which can achieve a low color difference appearance and thus meet the stringent appearance requirements of the aero-engine controller structural components. Example
[0043] A laser cladding repair material suitable for 5A06 aluminum alloy comprises the following components by mass percentage: Mg 6%, Zn 0.2%, Si 0.4%, RE 0.5%, Fe 0.1%, Cu 0.02%, with the balance being Al; the particle size of the laser cladding repair material is 100-150μm.
[0044] RE is a mixture of rare earth elements Y and Er, with a mass ratio of Y to Er of 1:1.5, i.e., Y 0.2% and Er 0.3%.
[0045] A laser cladding repair method with high bonding strength and low oxygen conductivity color difference includes the following steps: Step S1, Pre-treatment: The structural component to be repaired in this embodiment is a liquid cooling plate for a certain type of aircraft engine controller, made of 5A06 aluminum alloy, which developed cracks after long-term use. Figure 4 .from Figure 4 It can be seen that the crack in the structural component to be repaired has a certain depth. Therefore, a 60° U-shaped bevel is made at the crack until there is no crack at the bottom. The impurities and oxide film are removed by grinding with an electric wire brush grinder. Then, it is placed in anhydrous ethanol for ultrasonic cleaning and kept at 70°C for 2 hours in a vacuum oven. Step S2, Laser Cladding Repair: (1) High-purity argon gas (purity ≥ 99.99%) is injected into the environmental chamber to make the oxygen content in the environmental chamber less than 100 ppm, and the structural component to be repaired is transported to the workbench through the air curtain; (2) Preheat the structural components to be repaired in the environmental chamber, and control the preheating temperature at 200℃; (3) A high-precision coaxial powder feeding system is used to deliver the above-mentioned laser cladding repair material to the area to be repaired of the structural component to be repaired for laser cladding repair. The protective gas is high-purity argon (purity ≥ 99.99%). The parameters for laser cladding repair are as follows: the laser is an IPG fiber laser with a laser power of 2200W, a spot diameter of 2mm, a scanning speed of 15mm / s, a powder feeding rate of 1.2g / min, an overlap rate of 50%, a protective gas flow rate of 20L / min, and a powder feeding gas flow rate of 5L / min.
[0046] (4) Control the height of each cladding layer to 0.5 mm until the bottom surface to be repaired is completely covered by the cladding layer to complete one layer of repair. Control the temperature of the cladding layer to 150℃ for the next layer of cladding, and so on, until the height of the cladding layer is higher than the surface of the substrate after the cladding is completed.
[0047] Step S3: After the repaired structural component has cooled to room temperature in the environmental chamber, it is removed. The cladding area of the structural component is then precision machined. Referring to the drawings, high-precision CNC machining is used to restore the original dimensions and tolerances of the structural component. Finally, the entire structural component undergoes conductive oxidation treatment. The effect after conductive oxidation is shown in [see image]. Figure 5 ,from Figure 5 It can be seen that the surface of the repaired structural component is smooth and without obvious defects. The metallographic structure of the repaired structural component is shown below. Figure 6a , 6b As shown in Figure 6c, it can be seen that the cladding layer is free of defects such as pores and cracks, and the bonding between the cladding layers is relatively dense, which can achieve a high-strength connection between the layers.
[0048] Verification results: 1. After conductive oxidation, the substrate and the repaired area are basically the same, with a color difference value ΔE of about 1.23.
[0049] 2. A 3MPa hydraulic test was conducted, and no leakage occurred after holding the pressure for 30 minutes.
[0050] 3. After passing the ESS environmental stress screening, vibration in three directions did not cause cracking, and it can be used normally.
[0051] This invention addresses three major technical bottlenecks in existing technologies for repairing such structural components: insufficient bonding strength, easy oxidation leading to porosity, and significant color difference between the repaired area and the substrate after conductive oxidation. It provides a complete solution. The core of this solution lies in: First, a newly designed cladding powder with low silicon (Si: 0.3%–0.8%), high magnesium (Mg: 4.5%–6%), and containing zinc and rare earth elements. This composition has a high compatibility with 5-series aluminum alloy substrates, ensuring conductivity and color consistency after surface treatment from the source. Second, an ultra-low oxygen environment (≤100ppm) is used to completely suppress oxidation of the molten pool during repair, ultimately achieving high-strength bonding in the repaired area and uniformity in conductivity and appearance with the substrate.
[0052] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.
Claims
1. A laser cladding repair material with high bonding strength and low oxygen conductivity color difference, characterized in that, By mass percentage, it includes the following components: Mg 4.5%-6%, Zn 0.2%-0.4%, Si 0.3%-0.8%, RE 0.2%-0.6%, Fe≤0.2%, Cu≤0.1%, with the balance being Al; The RE is a mixture of rare earth elements Y and Er, wherein the mass ratio of Y to Er is 1:1.5; The particle size of the laser cladding repair material is 100-150 μm.
2. A laser cladding repair method with high bonding strength and low oxygen conductivity color difference, characterized in that, Includes the following steps: Step S1, Pre-treatment: Pre-treatment is performed on the area to be repaired of the structural component; Step S2: Laser cladding repair is performed using the laser cladding repair material described in claim 1 in an ultra-low oxygen environment; Step S3: After the repaired structural component is cooled to room temperature in the environmental chamber, it is taken out, the cladding area of the structural component is precision machined, and the entire structural component is subjected to conductive oxidation treatment.
3. The laser cladding repair method with high bonding strength and low oxygen conductivity color difference according to claim 2, characterized in that, The pretreatment in step S1 includes the following steps: the area to be repaired of the structural component is thoroughly cleaned using an electric wire brush grinder to remove impurities and oxide film, then ultrasonically cleaned in anhydrous ethanol, and kept at 70±10℃ in a vacuum oven for 2-4 hours.
4. The laser cladding repair method with high bonding strength and low oxygen conductivity color difference according to claim 2, characterized in that, In step S3, during precision machining, CNC high-precision numerical control is used to restore the original dimensions and tolerances of the structural parts.
5. The laser cladding repair method with high bonding strength and low oxygen conductivity color difference according to claim 2, characterized in that, In step S1, the material of the structural component to be repaired is 5-series aluminum alloy.
6. The laser cladding repair method with high bonding strength and low oxygen conductivity color difference according to claim 2, characterized in that, Step S2, laser cladding repair includes the following steps: (1) High-purity argon gas is injected into the environmental chamber to make the oxygen content in the environmental chamber less than 100ppm, and the structural component to be repaired is transported to the workbench through the air curtain; (2) The structural component to be repaired is preheated in the environmental chamber, and the preheating temperature is controlled at 150-200℃; (3) A high-precision coaxial powder feeding system is used to deliver the laser cladding repair material to the area to be repaired of the structural component to be repaired for laser cladding repair, and the protective gas is high-purity argon; (4) Control the height of each cladding layer to be 0.3-0.5 mm until the bottom surface to be repaired is completely covered by the cladding layer to complete one layer of repair. Control the temperature of the cladding layer to be 150±20℃ for the next layer of cladding, and so on, until the height of the cladding layer is higher than the surface of the substrate after the cladding is completed.
7. The laser cladding repair method with high bonding strength and low oxygen conductivity color difference according to claim 6, characterized in that, In step (3), the parameters of the laser cladding repair are as follows: laser power 2000-2500W, spot diameter 1.6-2.2mm, scanning speed 10-18mm / s, powder feeding amount 0.8-1.6g / min, overlap rate 50%-60%, protective gas flow rate 20-25L / min, and powder feeding gas flow rate 5-10L / min.
8. The laser cladding repair method with high bonding strength and low oxygen conductivity color difference according to claim 6, characterized in that, In steps (1) and (3), the purity of the high-purity argon gas is ≥99.99%.