Combined repairing method for machining assembly of air inlet casing of aero-engine

Abstract

The invention relates to the field of aero-engine part repairing, in particular to an aero-engine air inlet casing machining assembly combined repairing method. The method comprises the following steps that argon arc welding and laser cladding are conducted on the aero-engine air inlet casing machining assembly with cracks, the cracks are repaired, and the aero-engine air inlet casing machining assembly with the size and performance reaching or superior to those of an original state is obtained. According to the crack repairing method for the air inlet casing machining assembly of the aero-engine, the combined repairing method for repairing large-size cracks through argon arc welding and repairing small-size cracks through laser cladding is adopted, the repairing efficiency of repairing the large-size cracks and the repairing precision of the small-size cracks are guaranteed, and therefore the operation efficiency is improved, the product size is stabilized, and the product quality is improved. The repaired air inlet casing machining assembly can be continuously used, the service life of the air inlet casing machining assembly is prolonged, cost is reduced, efficiency is improved, and sustainable development is achieved.

Description

Technical Field

[0001] This invention relates to the field of aircraft engine parts repair, and specifically to a method for repairing aircraft engine intake casing by combining machined components. Background Technology

[0002] The intake casing of an aero-engine is a crucial load-bearing component. It is a casting made of ZL114A material, operating at an ambient temperature of approximately 100°C. Its structure is shown below. Figure 1 As shown. During prolonged service, the intake casing machining assembly is prone to developing cracks of varying sizes in multiple locations. However, cracks are unacceptable in this assembly; otherwise, it must be scrapped. Due to the high cost and long procurement cycle of parts, it is impossible to meet the repair cycle requirements for this type of engine. Therefore, there is an urgent need for crack repair capabilities for the intake casing machining assembly.

[0003] Currently, the repair of cracks in intake casing machining components mainly relies on single technologies such as laser additive manufacturing and arc additive manufacturing. However, these technologies are insufficient to address the issue of multiple cracks of varying sizes appearing in different parts of the intake casing machining components, making it difficult to efficiently and effectively repair these components using a single technology.

[0004] In view of this, the present invention provides a method for repairing the machined components of an aero-engine intake casing. Summary of the Invention

[0005] The technical problem to be solved by this invention is to provide a method for repairing machined components of an aero-engine intake casing. The aim is to develop an additive repair process for machined components of the intake casing based on a combination of argon arc welding and laser cladding technologies.

[0006] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: In a first aspect, a method for repairing a machined assembly of an aero-engine intake casing includes the following steps: repairing the cracked machined assembly of the aero-engine intake casing by argon arc welding and laser cladding, thereby obtaining a machined assembly of the aero-engine intake casing with dimensions and performance that meet or exceed those of the original state. The crack in the machined component of the aero-engine intake casing repaired by argon arc welding is a penetrating crack; The cracks in the machining components of the aero-engine intake casing that are repaired by laser cladding are non-penetrating cracks.

[0007] Based on the above technical solution, the present invention can be further improved as follows.

[0008] Furthermore, the specific steps include the following: (1) Grind the cracked part of the machined assembly of the air intake casing of the aircraft engine until the crack is eliminated to obtain the repair area on the machined assembly of the air intake casing of the aircraft engine. (2) The area to be repaired is repaired by argon arc welding and laser cladding to obtain the repair area; the repair area is inspected and repaired until the size and performance of the aero-engine intake casing machining component reach or exceed the original state are obtained.

[0009] Furthermore, in step (1), mechanical grinding is used for grinding, and the radius of the rounded corner is not less than 40 mm.

[0010] Furthermore, the thickness of the area to be repaired in step (1) is 3 mm to 20 mm.

[0011] Furthermore, the parameters for argon arc welding in step (2) are as follows: the welding wire is ZL114A, the welding thickness is 3~20 mm, the current / voltage is 50~120A, the gas flow rate is 4~20 L / min, AC is used, the tungsten electrode diameter is selected as Φ1.5~3 mm, the welding wire diameter is Φ1.5~3.5 mm, and argon gas is passed through the back side of the weld for protection during the welding process.

[0012] Furthermore, the parameters for laser cladding in step (2) are as follows: the laser cladding powder is aluminum-based alloy powder, the laser power is 500W~800W, the protective gas flow rate is 10~30 L / min, the scanning speed is 3~9 mm / s, the powder feeding gas flow rate is 5~13 L / min, the defocusing amount is 0~2, the powder feeding speed is 1~6 r / min, the channel spacing is 0.2~0.8 mm, the layer height is 0.2~0.8 mm, and the powder trough width is 2~8 mm.

[0013] Furthermore, the laser cladding powder is designated as AlSi10Mg.

[0014] The intake casing machining components are made of ZL114A, a high-strength cast aluminum alloy with excellent mechanical properties, casting performance, resistance to hot cracking, and weldability. It is primarily used to manufacture large structural components. ZL114A is an Al-Si-Mg alloy, with main constituent phases including α-solid solution, (α+Si) eutectic, MgSi, and Al3Ti. Therefore, argon arc welding repair was performed using the same welding wire as the intake casing machining component material, and laser cladding repair was conducted using aluminum-based alloy powders with similar composition to the intake casing machining component material, such as AlSi10Mg.

[0015] Furthermore, the inspection and repair of the repair area in step (2) includes non-destructive testing, machining, and dimensional inspection.

[0016] Furthermore, the non-destructive testing specifically includes inspecting the repair area through visual inspection, fluorescence, and X-ray.

[0017] Furthermore, fluorescence detection confirms the absence of cracks; X-ray detection confirms the absence of cracks in the repaired area, with a diameter ≥2.5mm and a total area <25 mm². 2 The pores.

[0018] The beneficial effects of this invention are: (1) In view of the cracks that appear in the machining components of the air intake casing, the present invention proposes an additive repair process based on argon arc welding technology and laser cladding technology, and establishes a complete repair process for cracks in the machining components of the air intake casing of aero engines, so as to ensure that the size and performance of the machining components of the air intake casing after repair reach or exceed the original state.

[0019] (2) The present invention uses ZL114A for argon arc welding and aluminum-based alloy powder for laser cladding to repair the intake casing machining components. The welding parameters are optimized and the welding effect is excellent. The strength of the argon arc welding repair can reach 87% of the original strength, and the strength of the intake casing machining components repaired by laser cladding can reach 98% of the original strength. The hardness value of the welded area of ​​the intake casing machining components repaired by laser cladding in the present invention meets the national standard and the national military standard. The laser cladding method and aluminum-based alloy powder used in the present invention are significantly better than argon arc welding using welding wire of the same grade ZL114A as the material itself in terms of metallographic structure, hardness and tensile strength.

[0020] (3) This invention uses a combination of argon arc welding and laser cladding to repair the machined components of the intake casing, further mitigating the problem of workpiece deformation; fluorescent detection shows no cracks, meeting the repair requirements; X-ray detection shows no cracks and no areas with a diameter ≥2.5mm and a total area <25mm. 2 The pores are present; all dimensions meet the usage requirements.

[0021] (4) This invention addresses the repair of cracks in a machining component of an aero-engine intake casing. It utilizes a combined repair method of argon arc welding to repair large-sized cracks and laser cladding to repair small-sized cracks, ensuring the repair efficiency of large-sized cracks and the repair accuracy of small-sized cracks. This improves work efficiency, stabilizes product dimensions, and allows the repaired machining component of the intake casing to continue to be used, extending the service life of the machining component of the intake casing, reducing costs and increasing efficiency, and achieving sustainable development. Attached Figure Description

[0022] Figure 1 Schematic diagram of the machining components of the intake casing; Figure 2 Flowchart for repairing machining components of the intake casing; Figure 3 This is a schematic diagram of the polishing process of the present invention; Figure 4 The following are metallographic images of the argon arc welding of the present invention; wherein, (a) is the microstructure of the ZL114A substrate; (b) is the microstructure of the argon arc weld; and (c) is the microstructure of the heat-affected zone of the argon arc welding. Figure 5 The present invention relates to laser cladding metallography; wherein, (a) the microstructure of laser cladding; and (b) the microstructure of the heat-affected zone of laser cladding. Figure 6 This is a diagram showing the dimensions of the tensile specimen. Figure 7 The average tensile strength of each specimen is shown in the diagram. Detailed Implementation

[0023] The principles and features of this invention are described below. The examples given are for illustrative purposes only and are not intended to limit the scope of the invention. Where specific techniques or conditions are not specified in the embodiments, they should be performed according to the techniques or conditions described in the literature in this field, or according to the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased through legitimate channels.

[0024] This embodiment relates to a method for repairing machined components of an aero-engine intake casing. Figure 2 ), including the following steps: (1) Grinding the welding area: Ensure the surface of the welding area of ​​the part is free of oil, dirt, and other debris, and grind the welding area. Before grinding, seal the relevant openings with masking tape to prevent metal shavings from entering, and remove the tape after grinding. Use mechanical grinding to completely remove the areas with cracks and defects, and the radius of the grinding fillet should not be less than 40 mm. Figure 3 As shown. Use a steel wire wheel to grind and polish the cladding area, removing the surface oxides around the cladding area by 10-20 mm until a metallic luster is exposed. Clean the cladding area with a white silk cloth soaked in anhydrous ethanol or acetone, and then blow it dry with compressed air.

[0025] (2) Laser cladding repair of non-penetrating small-sized cracks in the machining components of the aero-engine intake casing: (2-1) Equipment preparation and environmental requirements: Equipment Preparation: Turn on the equipment power supply regulator to control the network voltage within the range of 380±50V. Open the argon valve and check if the argon gas is sufficient; the argon gas pressure in the pipeline should be greater than 0.6 MPa. Check that the protective gas and powder feeder passages are functioning properly. Visually inspect the laser head toner focusing, ensuring good focusing and coaxiality. Check the operation of the water chiller; add distilled water if the cooling water is insufficient.

[0026] Environmental requirements: The temperature inside the cladding room should be maintained between 10 and 30°C, and the relative humidity should be maintained between 30% and 85%. No drafts are allowed. The pressure of bottled argon or liquid argon containers should not be lower than 1.0 MPa; otherwise, their use should be stopped and the containers replaced.

[0027] (2-2) Preparation of welding materials: The laser cladding powder should be aluminum-based alloy powder with a mesh size of 50-400. When taking it, heat it to 80-150℃ in a vacuum environment of <5Pa and hold for 50-100 min to dry it. Take only an appropriate amount of powder each time, and seal any remaining powder immediately. If possible, fill the container with inert gas. Use a heated powder container to heat the powder in the container at 120℃.

[0028] (2-3) Welding process: Laser cladding is used for additive repair. The material grade of the part is ZL114A, and the laser cladding powder grade is AlSi10Mg. The laser power is 500W~800W, the protective gas flow rate is 10~30 L / min, the scanning speed is 3~9 mm / s, the powder feeding gas flow rate is 5~13 L / min, the defocusing amount is 0~2, the powder feeding speed is 1~6 r / min, the track spacing is 0.2~0.8 mm, the layer height is 0.2~0.8 mm, and the powder tank width is 2~8 mm (Table 1).

[0029] (2-4) Product cladding: Before cladding, seal the relevant openings with masking tape to prevent metal powder from entering. Perform single-pass cladding on the ZL114A sample to confirm that the argon protection is effective, and the cladding path should be bright metallic. After cladding, wait for the product to cool for 30-60 minutes, use a brush to clean the metal powder on the product, remove the fixed product, then use compressed air to clean off any excess metal powder, and finally remove the sealing masking tape.

[0030] Table 1 Laser Cladding Process Parameters (2-5) Non-destructive testing: The product is inspected visually, using fluorescence and X-ray. The repaired surface should have a metallic luster and a smooth transition with the surrounding substrate, and should be free of defects such as cracks, burn-through, arc craters, lack of fusion, weld beads, porosity, and weld leaks (visual inspection); fluorescence detection should show no cracks; X-ray internal quality inspection: the repaired area should be free of cracks and have a diameter ≥2.5 mm and a total area <25 mm². 2 The pores are present.

[0031] (2-6) Post-weld machining and dimensional inspection: The cladding layer of the assembly surface is machined and the dimensions after machining are inspected. The inspection results meet the usage requirements.

[0032] (3) Argon arc welding repair of large penetrating cracks in the machining components of the aero-engine intake casing: (3-1) Equipment preparation and environmental requirements: Equipment Preparation: The selected welding power source should be a DC power supply with a steep droop, allowing for easy adjustment of welding parameters and stable operation under the required parameter specifications. The equipment should operate normally, possessing functions such as pre-gas supply, delayed gas shut-off, high-frequency arc initiation, and current attenuation. The mains voltage of the welding power source should be within the range of 380±50V.

[0033] Environmental requirements: The welding torch should be lightweight, flexible, and have good accessibility and conductivity. The nozzle and conductive parts should have good cooling, and the handle and conductive parts should have good insulation. The electrode chuck should reliably clamp the tungsten electrode. A heat-resistant ceramic nozzle should be used, and the shape of the nozzle cavity should provide a certain stiffness for the airflow to achieve a good protective effect. The indoor temperature of the welding room should not be lower than 16℃, the relative humidity should not be greater than 60%, and there should be no draft. When the pressure of bottled argon or liquid argon tank is lower than 1.0 MPa, stop using it and replace it.

[0034] (3-2) Preparation of welding materials: Cerium tungsten electrode is selected. After grinding, the tip of the tungsten electrode should be a flat-headed cone with a diameter of about half that of the tungsten electrode. Protective glasses should be worn during grinding to prevent metal particles from entering the eyes. When cleaning the welding wire, first use a white cloth soaked in anhydrous ethanol or acetone to remove oil and dirt from the surface of the welding wire, then use 240# metallographic sandpaper to clean the oxides on the surface of the welding wire, and finally use a white cloth soaked in anhydrous ethanol or acetone to clean it again, and finally blow it dry with compressed air.

[0035] (3-3) Welding process: TIG welding is used, with welding wire grade ZL114A, welding thickness of 1~6 mm, current / voltage of 50~120A, gas flow rate of 4~20 L / min, AC welding, tungsten electrode diameter of Φ1.5~3 mm, and welding wire diameter of Φ1.5~3.5 mm. During welding, argon gas is used for protection on the back side of the weld. When there are many welding parts, symmetrical welding, intermittent welding, or welding adjacent parts should be carried out after the temperature of the previous weld has dropped before welding. For details of the argon arc welding process parameters, please refer to Table 2.

[0036] Table 2. Argon Arc Welding Process Parameters (3-4) Non-destructive testing: The repaired weld area is inspected visually or with a low-magnification (10x) magnifying glass, and the product is inspected using fluorescence and X-ray. The repaired surface should have a metallic luster and a smooth transition with the surrounding substrate, and should be free of defects such as cracks, burn-through, arc craters, lack of fusion, weld beads, porosity, and weld leaks (visual inspection); fluorescence detection should show no cracks; X-ray internal quality inspection: the repaired area should be free of cracks with a diameter ≥2.5 mm and a total area <25 mm². 2 The pores are present.

[0037] (3-5) Post-weld machining and dimensional inspection: The cladding layer of the assembly surface is machined and the dimensions after machining are inspected. The inspection results meet the usage requirements.

[0038] The following description uses specific examples to further illustrate the point.

[0039] Example 1 The laser cladding process parameters and the argon arc welding process parameters in this embodiment are as follows: Laser cladding welding process: Additive repair adopts laser cladding. The part material grade is ZL114A, the laser cladding powder grade is AlSi10Mg, the laser power is 500W, the protective gas flow rate is 10 L / min, the scanning speed is 3 mm / s, the powder feeding gas flow rate is 5L / min, the defocusing amount is 0, the powder feeding speed is 1 r / min, the pass spacing is 0.2 mm, the layer height is 0.2 mm, and the powder tank width is 2 mm.

[0040] Argon arc welding process: TIG welding is used with ZL114A welding wire. The welding thickness is 3 mm, the current / voltage is 50A, the gas flow rate is 4 L / min, AC is used, and the tungsten electrode diameter is Φ1.5 mm. Argon gas is used for shielding on the back side of the weld during welding. When welding multiple parts, symmetrical welding, intermittent welding, or welding adjacent parts should be carried out after the temperature of the previous weld section has decreased before welding.

[0041] Example 2 The laser cladding process parameters and the argon arc welding process parameters in this embodiment are as follows: Laser cladding welding process: Additive repair adopts laser cladding. The part material grade is ZL114A, the laser cladding powder grade is AlSi10Mg, the laser power is 650W, the protective gas flow rate is 20 L / min, the scanning speed is 6 mm / s, the powder feeding gas flow rate is 7L / min, the defocusing amount is 1, the powder feeding speed is 3 r / min, the pass spacing is 0.6mm, the layer height is 0.6mm, and the powder tank width is 5mm.

[0042] Argon arc welding process: TIG welding is used with ZL114A welding wire. The welding thickness is 10 mm, the current / voltage is 80A, the gas flow rate is 12 L / min, AC is used, and the tungsten electrode diameter is Φ2 mm. Argon gas is used for protection on the back side of the weld during welding. When there are many welding parts, symmetrical welding, intermittent welding, or welding adjacent parts should be carried out after the temperature of the previous weld has dropped before welding.

[0043] Example 3 The laser cladding process parameters and the argon arc welding process parameters in this embodiment are as follows: Laser cladding welding process: Additive repair adopts laser cladding. The part material grade is ZL114A, the laser cladding powder grade is AlSi10Mg, the laser power is 800W, the protective gas flow rate is 30 L / min, the scanning speed is 9 mm / s, the powder feeding gas flow rate is 13 L / min, the defocusing amount is 2, the powder feeding speed is 6 r / min, the pass spacing is 0.8 mm, the layer height is 0.8 mm, and the powder tank width is 8 mm.

[0044] Argon arc welding process: TIG welding is used with ZL114A welding wire. The welding thickness is 20 mm, the current / voltage is 120 A, the gas flow rate is 20 L / min, AC is used, the tungsten electrode diameter is Φ3 mm, and the welding wire diameter is Φ3.5 mm. During the welding process, argon gas is used for protection on the back side of the weld. When there are many welding parts, symmetrical welding, intermittent welding, or welding adjacent parts should be carried out after the temperature of the previous weld has dropped before welding.

[0045] Comparative Example 1 The laser cladding process parameters and argon arc welding process parameters for Comparative Example 1 are as follows: Argon arc welding process: TIG welding is used with ZL114A welding wire. The welding thickness is 3 mm, the current / voltage is 40A, the gas flow rate is 40 L / min, AC is used, and the tungsten electrode diameter is Φ1 mm. The welding wire diameter is Φ1 mm. During the welding process, argon gas is used for protection on the back side of the weld. When there are many welding parts, symmetrical welding, intermittent welding, or welding adjacent parts should be carried out after the temperature of the previous weld has decreased before welding.

[0046] Laser cladding welding process: Additive repair adopts laser cladding. The material grade of the part is ZL114A, the laser cladding powder grade is AlSi10Mg, the laser power is 400W, the protective gas flow rate is 8 L / min, the scanning speed is 10 mm / s, the powder feeding gas flow rate is 20 L / min, the defocusing amount is 3, the powder feeding speed is 8 r / min, the pass spacing is 1 mm, the layer height is 1 mm, and the powder tank width is 10 mm.

[0047] Comparative Example 2 The laser cladding process parameters and the argon arc welding process parameters are as follows: Argon arc welding process: TIG welding is used with ZL114A welding wire. The welding thickness is 3 mm, the current / voltage is 130A, the gas flow rate is 10 L / min, AC is used, the tungsten electrode diameter is Φ1 mm, and the welding wire diameter is Φ3.5 mm. During the welding process, argon gas is used for protection on the back side of the weld. When there are many welding parts, symmetrical welding, intermittent welding, or welding adjacent parts should be carried out after the temperature of the previous weld has dropped before welding.

[0048] Laser cladding welding process: Additive repair adopts laser cladding. The part material grade is ZL114A, the laser cladding powder grade is AlSi10Mg, the laser power is 1000W, the protective gas flow rate is 32 L / min, the scanning speed is 10 mm / s, the powder feeding gas flow rate is 15 L / min, the defocusing amount is 3, the powder feeding speed is 10 r / min, the pass spacing is 1 mm, the layer height is 1.5 mm, and the powder tank width is 10 mm.

[0049] Test case 1. Metallographic experiment.

[0050] In Example 1, ZL114A specimens were prepared by wire cutting. The observation surface was ground and polished, and etched with a solution of 2 ml HF + 3 ml HCl + 5 ml HNO3 + 190 ml H2O. The specimens were then observed and analyzed using a Zeiss metallographic microscope.

[0051] (1) Analysis of metallographic experimental results of argon arc welding: After ZL114A slices were processed, butt welding was performed. The microstructure of the weld joint was observed, and the metallographic examination results are as follows: Figure 4 As shown, Figure 4 Image (a) shows the microstructure of the ZL114A substrate, which consists of uniform equiaxed crystals. Figure 4 Image (b) is a metallographic image of the welded area. It shows that the microstructure of the weld is the same as the ZL114A matrix, consisting of equiaxed grains, but with finer grains. Near the fusion line, the weld exhibits even larger equiaxed grains. During cooling, the coarse grains gradually shrink, forming a more uniform and finer equiaxed grain structure, such as... Figure 4 As shown in (c). Metallographic testing results show that after argon arc welding, the entire welded area of ​​ZL114A material is free of cracks, porosity, and slag inclusions, meeting the technical requirements.

[0052] (2) Analysis of laser cladding metallographic experimental results: After processing ZL114A slices, laser cladding was performed. The microstructure of the cladding area was observed, and the metallographic examination results are as follows: Figure 5 As shown, Figure 5 Image (a) shows the microstructure of the laser cladding region. It can be observed that after laser cladding, the entire cladding region of ZL114A exhibits a uniform equiaxed crystal structure, with finer and more uniform grains. Figure 5 As can be seen from (b), the heat-affected zone of the entire laser cladding area is relatively small. Metallographic examination results show that after laser cladding, the entire welding area of ​​Z114A material is free of cracks, pores, and slag inclusions, meeting the technical requirements.

[0053] 2. Hardness test.

[0054] Microhardness was measured using a Vickers microhardness tester on the cross-sections of the repaired areas in Examples 1 and 3. The load was 1 kgf, and the loading time was 10 s. At least five hardness points were tested on the weld area, heat-affected zone, and substrate of each specimen cross-section. The average hardness values ​​of each specimen are shown in Table 3. The hardness test results show that the hardness of the heat-affected zone after laser cladding is basically consistent with that of the base material, indicating that the heat-affected zone of ZL114A repaired by laser cladding is small, consistent with the microstructure test results. The hardness of the heat-affected zone after argon arc welding is higher than that of the weld and the base material, possibly related to the coarse grain structure of the heat-affected zone. According to the mechanical property requirements in Volume 3 of the "China Aviation Materials Handbook - Aluminum Alloys and Magnesium Alloys," only the lower limit of the hardness of ZL114A material is specified, not the upper limit. Therefore, the hardness of the intake casing machining components repaired by argon arc welding and laser cladding meets the requirements, as shown in Tables 3 and 4.

[0055] Table 3 Vickers hardness test table for Examples 1 to 3 Table 4. Vickers Hardness Test Table for Comparative Examples 1 and 2 In addition, an inspection of the above-mentioned repaired areas revealed poor weld formation and numerous defects, failing to meet usage requirements.

[0056] 3. Strength test.

[0057] Tensile properties were determined using a universal tensile testing machine to assess the impact of weld repair on the mechanical properties of the intake casing machined components. The specimen dimensions are as follows: Figure 6 As shown, the test specimen material was ZL114A. All specimens were prepared by wire cutting and mechanically ground to remove weld excess, ensuring the weld repair area was flush with the substrate. Burrs were then removed with sandpaper. The test temperature was room temperature, and the test speed was 0.5 mm / min. The specimen condition and test results are as follows. Figure 7 As shown, the room temperature tensile strength of ZL114A material decreased from 245.33 MPa before TIG welding to 213.33 MPa after TIG welding, indicating that the strength after TIG welding repair is 87% of the original strength. The room temperature tensile strength of ZL114A material also decreased from 245.33 MPa before laser cladding to 240.33 MPa after laser cladding, indicating that the strength after laser cladding is 98% of the original strength. This demonstrates that the strength of the machined intake casing components repaired using TIG welding and laser cladding meets the technical requirements.

[0058] 4. Welding inspection.

[0059] Dimensional inspection: The dimensional requirements and results of the machined components of the repaired intake casing in Example 1 are shown in Table 5. The inspection results show that the dimensions of the repaired turbine casing meet the requirements of the fault inspection process and drawings.

[0060] Table 5. Inspection table of various dimensions of the repaired intake casing assembly. In summary, the invention employs argon arc welding and laser cladding to repair ZL114A, and studies the influence of process parameters such as welding materials, welding current, shielding gas flow rate, laser power, and powder feeding speed on the weld, thus forming the optimal process parameters for welding repair of ZL114A material.

[0061] Sample pieces were cut for simulated repair, and the mechanical properties of the repaired materials were compared and evaluated. The process was verified by characterizing and testing the microstructure, hardness, strength, non-destructive testing and other indicators and properties of the repaired materials. Finally, the machine was installed and tested to verify whether the machined components of the repaired intake casing meet the engine's usage requirements.

[0062] To meet the dimensional requirements of the intake casing machining components, after welding repair, the excess welds need to be machined. Therefore, it is necessary to study the machining process to ensure that the repaired intake casing machining components meet the requirements for engine assembly and use.

[0063] In summary, this invention addresses the repair of cracks in machining components of an aero-engine intake casing. It employs a combined repair method that combines argon arc welding for repairing large cracks with laser cladding for repairing small cracks. This ensures both the repair efficiency for large cracks and the repair precision for small cracks, thereby improving operational efficiency, stabilizing product dimensions, and allowing the repaired machining components of the intake casing to continue in service, thus extending their service life, reducing costs, increasing efficiency, and achieving sustainable development.

[0064] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for repairing machined components of an aero-engine intake casing, characterized in that, The process includes the following steps: repairing the cracked aero-engine intake casing machining components by argon arc welding and laser cladding to obtain aero-engine intake casing machining components with dimensions and performance that meet or exceed the original condition. The crack in the argon arc welding repair of the machined component of the aero-engine intake casing is a penetrating crack; The cracks in the machining components of the aero-engine intake casing that are repaired by laser cladding are non-penetrating cracks.

2. The method for repairing machined components of an aero-engine intake casing according to claim 1, characterized in that, The specific steps include the following: (1) Grind the cracked part of the machined assembly of the air intake casing of the aircraft engine until the crack is eliminated to obtain the repair area on the machined assembly of the air intake casing of the aircraft engine. (2) The area to be repaired is repaired by argon arc welding and laser cladding to obtain the repair area; the repair area is inspected and repaired until the size and performance of the aero-engine intake casing machining component reach or exceed the original state are obtained.

3. The method for repairing machined components of an aero-engine intake casing according to claim 2, characterized in that, In step (1), mechanical grinding is used, and the radius of the rounded corner is not less than 40 mm.

4. The method for repairing machined components of an aero-engine intake casing according to claim 2, characterized in that, The thickness of the area to be repaired in step (1) is 3 mm to 20 mm.

5. The method for repairing machined components of an aero-engine intake casing according to claim 2, characterized in that, The parameters for argon arc welding in step (2) are as follows: welding wire is ZL114A, welding thickness is 3 mm to 20 mm, current is 50 to 120 A, gas flow rate is 4 to 20 L / min, AC is used, tungsten electrode diameter is Φ1.5 to 3 mm, welding wire diameter is Φ1.5 to 3.5 mm, and argon gas is used for protection on the back side of the weld during the welding process.

6. The method for repairing machined components of an aero-engine intake casing according to claim 2, characterized in that, The parameters for laser cladding in step (2) are as follows: the laser cladding powder is aluminum-based alloy powder, the laser power is 500W~800W, the protective gas flow rate is 10~30 L / min, the scanning speed is 3~9 mm / s, the powder feeding gas flow rate is 5~13 L / min, the defocusing amount is 0~2, the powder feeding speed is 1~6 r / min, the channel spacing is 0.2~0.8 mm, the layer height is 0.2~0.8 mm, and the powder trough width is 2~8 mm.

7. The method for repairing machined components of an aero-engine intake casing according to claim 6, characterized in that, The laser cladding powder is designated as AlSi10Mg.

8. The method for repairing machined components of an aero-engine intake casing according to claim 2, characterized in that, The inspection and repair of the repair area in step (2) includes non-destructive testing, machining, and dimensional inspection.

9. The method for repairing machined components of an aero-engine intake casing according to claim 8, characterized in that, The non-destructive testing specifically includes inspecting the repair area through visual inspection, fluorescence, and X-ray.

10. The method for repairing machined components of an aero-engine intake casing according to claim 9, characterized in that, Fluorescence detection confirms the absence of cracks; X-ray examination confirms that the repaired area has no cracks, a diameter ≥ 2.5 mm, and a total area < 25 mm². 2 The pores.

Images