Laser additive repairing method for 2B06 aluminum alloy hinge part

Abstract

The invention relates to the technical field of remanufacturing, in particular to a 2B06 aluminum alloy hinge part laser additive repairing method which comprises the following specific steps: S1, pretreatment of a 2B06 aluminum alloy damaged hinge part; s3, the damaged aluminum alloy surface is repaired; s4, cladding reinforcing ribs; s5, the repaired aluminum alloy part is subjected to post-treatment; s6, the damaged hinge part and the lossless hinge part are used for verifying and repairing processes; alMnSc aluminum alloy powder is adopted as a raw material, a laser cladding method is applied, laser cladding repairing is carried out on the aluminum alloy by optimizing parameters such as laser power and scanning speed, meanwhile, reinforcing ribs are cladded at the junction of a multi-section discontinuous circular ring and a flat plate, after cladding is completed, low-temperature aging treatment is carried out firstly, then surface ultrasonic impact is carried out, and the composite material is obtained. The performance of the repaired product is remarkably enhanced and is far higher than the repairing strength of an argon arc welding technology, the performance of the aluminum alloy part is greatly improved, and the problem that the aluminum alloy part is difficult to weld and repair is solved.

Description

Technical Field

[0001] The invention relates to the technical field of remanufacturing, and in particular to a laser additive repair method for a 2B06 aluminum alloy hinge part. Background Art

[0002] High-strength deformed aluminum alloys are widely used in the aviation field due to their excellent mechanical properties. 2B06 aluminum alloy is a typical high-strength aluminum alloy on aircraft, and its applications include hinges, wall panels, etc. 2B06 aluminum alloy hinges mainly play a transmission role on aircraft. During the service of the hinge, cracks often appear at the R corner of the hinge ear, and even break. In order to extend the service life of the parts, the parts need to be repaired to restore the external dimensions and mechanical properties of the damaged parts. Traditional repair methods are mostly fusion welding, but pores and thermal cracks are prone to occur during the fusion welding of aluminum alloys, and the mechanical properties are significantly reduced.

[0003] At present, in addition to conventional fusion welding, laser cladding repair technology for aluminum alloys has also emerged. Laser deposition repair has the advantages of high laser energy density, low heat input, and fine weld grains. The development of this technology provides a new solution for the performance restoration of damaged high-strength aluminum alloy parts. Compared with argon arc welding repair technology, the microstructure of the laser additive repair area is finer and the mechanical properties are higher. Laser additive repair of high-strength deformed aluminum alloys using heterogeneous alloy powders can improve the alloy's resistance to thermal cracking while improving its mechanical properties.

[0004] The relevant patents for laser cladding repair of aluminum alloys are as follows: Patent 201120540171.5 discloses a laser rapid repair device for defects in aluminum alloy guide blades. Its advantage is that it uses visual guidance technology, which greatly shortens the repair time and improves the success rate of one-time repair.

[0005] Chinese patent number 202210112878.9 discloses a 5-series aluminum alloy laser repair process and a method for preparing the Al-Mg-Sc-Zr powder used therein. AlMgScZr powder is used to repair the 5-series aluminum alloy, and corresponding process parameter ranges are established for powders with different characteristics to achieve defect control during the laser repair process of aluminum alloy structural parts.

[0006] Chinese patent number 202210112886.3 discloses a method for small-spot laser additive repair of 7 series aluminum alloy under atmosphere protection conditions. Al-Mg-Sc-Zr aluminum alloy is used as the repair material. A small-spot laser is used to repair 7 series aluminum alloy under an inert atmosphere protection environment. By controlling the process parameters, a repair product with no significant defects, a density higher than 99.9%, and tensile properties better than the parent material is obtained.

[0007] Chinese patent number 202310747353.7 discloses a high-strength aluminum alloy laser additive repair method based on multi-dimensional stress regulation. By prestressing before repair, adding a magnetic field during the repair process, and presetting compressive stress after repair, the defects in the repair area are reduced and the service life is extended.

[0008] However, there is no research on additive repair of 2B06 aluminum alloy, which has a low absorption rate of laser, a large tendency to crack, and a significant softening effect after cladding. How to ensure that the heat-treated aluminum alloy repair still maintains high strength and long life is a difficult problem that needs to be solved urgently. Summary of the invention

[0009] In order to solve the above problems, the present invention proposes a laser additive repair method for 2B06 aluminum alloy hinge parts.

[0010] A laser additive repair method for 2B06 aluminum alloy hinge parts, the specific steps are as follows:

[0011] Pretreatment of damaged hinge parts of S1 and 2B06 aluminum alloy:

[0012] Remove the surface oil stains, polish and remove the cracks on the surface of the damaged hinge parts, and make a smooth transition with the substrate;

[0013] S2. Pretreatment of repair powder:

[0014] The aluminum alloy powder is vacuum dried at a certain temperature, and after the powder is cooled, it is taken out and loaded into a powder feeder, and stirring is started;

[0015] S3. Repair the damaged aluminum alloy surface:

[0016] S31, installing the damaged hinge parts on the fixed heat sink;

[0017] S32, turn on the water cooler, robot, and laser in sequence, and after the equipment is stable, plan the repair path according to the damage form and teach correctly, turn on the protective gas, start feeding powder and turn on the laser, and perform laser repair on the aluminum alloy surface layer by layer;

[0018] S4, cladding reinforcement ribs: continue to deposit reinforcement ribs at the junction of the multi-segment discontinuous circular ring and the flat plate of the damaged hinge part, the width of the reinforcement ribs is the same as the thickness of the circular ring, and the process is the same as step S3;

[0019] S5. Post-processing the repaired aluminum alloy parts: placing the damaged hinge parts, the fixed heat sink and the mandrel inserted into the hole of the multi-segment discontinuous ring, which are clamped and fixed together by a C-type clamp as a whole, in a heat treatment oven for heat treatment at 150-180°C for 1-2 hours, air cooling to room temperature, and then performing ultrasonic impact treatment on the repaired parts of the aluminum alloy parts, and finally machining the aluminum alloy parts;

[0020] S6. Use damaged hinge parts and intact hinge parts to verify the repair process:

[0021] The damaged hinge part is repaired according to steps S1 to S5. After the repair, the mandrel is inserted into the multi-segment discontinuous circular ring of the high-strength steel hinge and the multi-segment discontinuous circular ring of the damaged hinge part to form a tensile specimen assembly. The upper clamping section of the universal testing machine clamps the upper flat plate area of ​​the high-strength steel hinge, and the lower clamping section of the universal testing machine clamps the lower flat plate area of ​​the repaired damaged hinge part to test the maximum tensile force. If the average value of the maximum tensile force of the repaired damaged hinge part reaches more than 97% of the average value of the maximum tensile force measured of the intact hinge part, it means that the above-mentioned repair process is feasible.

[0022] The step S1 of removing surface oil stains is to clean the surface of the aluminum alloy with ethanol or acetone.

[0023] The aluminum alloy powder in step S2 is specifically AlMgScZr.

[0024] The particle size of the aluminum alloy powder is 53-150 μm.

[0025] The aluminum alloy powder is prepared by vacuum induction melting gas atomization or rotating disk atomization, and the drying temperature is 100-120° C. and the drying time is 2-4 hours.

[0026] The laser power of step S32 is 2kW-4kW, the spot diameter is 2-3mm, the moving speed is 5-15mm / s, the powder barrel speed is 1-2r / min, and the protective gas and powder feeding gas are argon.

[0027] The powder delivery gas flow rate is 2-5 L / min, the protective gas flow rate is 5-20 L / min, the overlap rate is 40%-60%, and the lifting amount of each layer is 0.5-0.8 mm.

[0028] The laser beam is at an angle of 100°-110° to the laser moving direction. After each cladding layer, the repaired surface is polished with a grinding head.

[0029] During the cladding process, the temperature of the parts is monitored in real time. When the temperature rises above 50°C, cladding is stopped and cladding is continued after cooling.

[0030] In the step S5, the ultrasonic impact treatment has an impact frequency of 10000-20000 Hz, the impact head is an aluminum head, and continuous and uniform ultrasonic impact is performed 2-3 times.

[0031] The beneficial effects of the present invention are as follows: AlMnSc aluminum alloy powder is used as raw material, and a laser cladding method is used. By optimizing parameters such as laser power and scanning speed, the aluminum alloy is laser clad and repaired. At the same time, reinforcing ribs are clad at the junction of the multi-segment discontinuous circular ring and the flat plate. After the cladding is completed, a low-temperature aging treatment is first performed and then a surface ultrasonic impact is performed, so that the performance of the repaired product is significantly enhanced, which is far higher than the repair strength of argon arc welding technology, greatly improving the performance of aluminum alloy parts, and solving the problem of difficult welding and repair of aluminum alloy parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0033] Figure 1 It is a schematic diagram of a damaged hinge part of 2B06 aluminum alloy of the present invention;

[0034] Figure 2 This is a schematic diagram of an optimized fixed heat dissipation block of the present invention;

[0035] Figure 3 Schematic diagram of the repair clamp;

[0036] Figure 4 This is a schematic diagram of the repaired 2B06 aluminum alloy damaged hinge parts;

[0037] Figure 5 Schematic diagram of the tensile specimen assembly for maximum tensile force determination.

[0038] In the figure, 1. damaged hinge parts; 2. surface cracks; 3. fixed heat sink; 4. semicircular groove; 5. left groove; 6. right groove; 7. core rod; 8-13. C-type clamp; 14. reinforcing rib; 15. high-strength steel hinge. DETAILED DESCRIPTION

[0039] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further described below.

[0040] Example:

[0041] like Figures 1 to 5 As shown, a laser additive repair method for 2B06 aluminum alloy hinge parts, the specific steps are as follows:

[0042] Pretreatment of damaged hinge parts of S1 and 2B06 aluminum alloy:

[0043] Remove the surface oil stains, grind away the cracks and damages on the hinge parts 1 and 2, grind away the cracks and damages on the hinge surface, and make a smooth transition with the substrate;

[0044] S2. Pretreatment of repair powder:

[0045] The aluminum alloy powder is vacuum dried at a certain temperature, and after the powder is cooled, it is taken out and loaded into a powder feeder, and stirring is started;

[0046] S31 Install the damaged hinge parts on the fixed heat sink;

[0047] S32, turn on the water cooler, robot, and laser in sequence, and after the equipment is stable, plan the repair path according to the damage form and teach correctly, turn on the protective gas, start feeding powder and turn on the laser, and perform laser repair on the aluminum alloy surface layer by layer;

[0048] S4, cladding reinforcement ribs: continue to deposit reinforcement ribs 14 at the junction of the multi-segment discontinuous circular ring and the flat plate of the damaged hinge part 1, the width of the reinforcement ribs is the same as the thickness of the circular ring, and the process is the same as step S3;

[0049] S5. Post-process the repaired aluminum alloy parts:

[0050] The damaged hinge part 1, the fixed heat sink block 3 and the core rod 7 inserted into the hole of the multi-stage discontinuous ring, which are clamped and fixed together by the C-type clamps 8 to 13, are placed in a heat treatment oven as a whole for heat treatment at 180°C for 1 hour, and then air-cooled to room temperature. The repaired part of the aluminum alloy part is then subjected to ultrasonic impact treatment, and finally the aluminum alloy part is machined to improve the hardness of the cladding layer.

[0051] The area outside the area to be repaired was protected with aluminum foil, and then the repaired and strengthened area was treated using an ultrasonic impact process;

[0052] S6. Use damaged hinge parts and intact hinge parts to verify the repair process:

[0053] The damaged hinge part is repaired according to steps S1 to S5. After the repair, the core rod 7 is inserted into the multi-segment discontinuous circular ring of the high-strength steel hinge 15 and the multi-segment discontinuous circular ring of the damaged hinge part 1 to form a tensile specimen assembly. The upper clamping section of the universal testing machine clamps the upper flat plate area of ​​the high-strength steel hinge 15, and the lower clamping section of the universal testing machine clamps the lower flat plate area of ​​the repaired damaged hinge part 1 to test the maximum tensile force. If the average value of the maximum tensile force of the repaired damaged hinge part reaches more than 97% of the average value of the maximum tensile force measured of the intact hinge part, it means that the above-mentioned repair process is feasible.

[0054] In response to the current difficulties in repairing 2B06, we creatively proposed to use AlMnSc powder laser repair combined with ultrasonic impact technology, and finally obtained a repair part with fewer defects and high strength. This solved the problems of many defects and easy softening in conventional repair methods of 2B06 aluminum alloy, improved the mechanical properties of the product, improved the original stress structure, extended the service life of the product, ensured flight safety, and has extremely high economic benefits.

[0055] The step S1 of removing surface oil stains is to clean the surface of the aluminum alloy with ethanol or acetone to make it clean for subsequent processing.

[0056] The aluminum alloy powder of step S2 is specifically AlMnSc, and the composition of AlMnSc is Mn: 5%, Mg: 1.5%, Sc: 0.7%, and the balance is Fe. It has few defects and high strength.

[0057] The particle size of the aluminum alloy powder is 53-150 μm.

[0058] The aluminum alloy powder is prepared by vacuum induction melting gas atomization or rotating disk atomization, and the drying temperature is 105° C. and the drying time is 2 hours.

[0059] The specific installation steps of step S31 are as follows:

[0060] The fixed heat sink block 3 has a semicircular groove 4 for fitting the multi-section discontinuous circular ring portion of the damaged hinge part;

[0061] A left groove 5 and a right groove 6 are provided in the middle of the fixed heat dissipation block 3;

[0062] The upper end of the C-type clamp 8-13 is pressed on the damaged hinge part 1, and the lower end extends into the left groove 5 or the right groove 6. The C-type clamp 8-13 is used to fix the damaged hinge part 1;

[0063] Inserting the mandrel 7 into the hole of the discontinuous circular ring in multiple sections to control the deformation of the multiple discontinuous circular ring of the hinge part 1;

[0064] The material of the fixed heat sink block 3 is aluminum bronze, and the material of the core rod 7 is high-strength steel.

[0065] The laser power of step S32 is 2.8 kW, the spot diameter is 2 mm, the moving speed is 10 mm / s, the powder barrel speed is 1.5 r / min, and the protective gas and powder feeding gas are argon.

[0066] The powder delivery carrier gas flow rate is 3 L / min, the protective gas flow rate is 15 L / min, the overlap rate is 60%, and the lifting amount of each layer is 0.6 mm.

[0067] The laser beam is at an angle of 105° to the direction of laser movement to prevent reflected laser from damaging the optical fiber and laser. After each cladding pass, the repair surface is polished with a grinding head to remove the oxide layer. At the same time, it can be fully cooled to reduce the performance deterioration caused by continuous heat effects until the repair is completed.

[0068] During the cladding process, the temperature of the parts is monitored in real time. When the temperature rises above 50°C, cladding is stopped immediately and cladding is continued after cooling.

[0069] In the step S5, the ultrasonic impact treatment is performed at an impact frequency of 10000-20000 Hz, the impact head is an aluminum head, and continuous and uniform ultrasonic impact is performed 2-3 times. Subsequently, the repaired aluminum alloy is machined and surface treated so that the part size and surface state meet the process requirements.

[0070] AlMgScZr aluminum alloy powder is used as the raw material, and the laser cladding method is used. By optimizing the laser power and scanning speed parameters, the aluminum alloy is repaired by laser cladding. At the same time, reinforcing ribs are clad on both sides of the hinge ear. After the cladding is completed, the surface ultrasonic impact is performed. The performance of the repaired product is significantly enhanced, which is far higher than the repair strength of argon arc welding technology. It greatly improves the performance of aluminum alloy parts, enhances fatigue performance while repairing, and solves the problem of difficult welding repair of aluminum alloy parts.

[0071] The material of the high-strength steel hinge 15 in step S6 is AF410 ultra-high-strength steel.

[0072] In addition, the repaired damaged hinge parts are replaced with undamaged hinge parts to test their maximum tensile force.

[0073] The maximum tensile forces of the damaged hinge parts after repair were measured to be 22386N, 22478N, and 22486N, with an average value of 22450N. The maximum tensile forces of the intact hinge parts were 22539N, 22458N, and 22486N, with an average value of 22494N. The average value of the maximum tensile forces of the damaged hinge parts after repair was 99.8% of the average value of the maximum tensile forces of the intact hinge parts, which was greater than 97%, indicating that the above repair process was feasible.

[0074] AlMnSc aluminum alloy powder is used as raw material and laser cladding method is used. By optimizing laser power and scanning speed parameters, the aluminum alloy is repaired by laser cladding. At the same time, reinforcing ribs are clad at the junction of the multi-segment discontinuous ring and the flat plate. After cladding, low-temperature aging is carried out first and then surface ultrasonic impact is performed. This significantly enhances the performance of the repaired product, which is far higher than the repair strength of argon arc welding technology. The maximum tensile force of the damaged hinge parts after repair reaches more than 97% of the maximum tensile force of the intact hinge parts, solving the problem of difficult welding repair of aluminum alloy hinge parts.

[0075] If the average value of the maximum tensile force of the repaired damaged hinge part reaches more than 97% of the average value of the maximum tensile force measured for the intact hinge part, the above repair process is determined to be feasible.

[0076] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions only describe the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A laser additive repair method for 2B06 aluminum alloy hinge parts, characterized in that: The specific steps are as follows: Pretreatment of damaged hinge parts of S1 and 2B06 aluminum alloy: Remove the surface oil stains, polish and remove the surface cracks and damages of the damaged hinge parts (1) and (2), and make a smooth transition with the base body; S2. Pretreatment of repair powder: The aluminum alloy powder is vacuum dried at a certain temperature, and after the powder is cooled, it is taken out and loaded into a powder feeder, and stirring is started; S3. Repair the damaged aluminum alloy surface: S31, installing the damaged hinge part (1) on the fixed heat sink (3); S32, turn on the water cooler, robot, and laser in sequence, and after the equipment is stable, plan the repair path according to the damage form and teach correctly, turn on the protective gas, start feeding powder and turn on the laser, and perform laser repair on the aluminum alloy surface layer by layer; S4, cladding reinforcement ribs: continue to deposit reinforcement ribs (14) at the junction of the multi-segment discontinuous circular ring and the flat plate of the damaged hinge part (1), the width of the reinforcement ribs being the same as the thickness of the circular ring, and the process is the same as step S3; S5. Post-processing the repaired aluminum alloy parts: placing the damaged hinge parts (1), the fixed heat sink (3) and the core rod (7) inserted into the hole of the multi-stage discontinuous ring, which are clamped and fixed together by C-type clamps (8) to (13), in a heat treatment oven as a whole for heat treatment at 150 to 180° C. for 1 to 2 hours, and air cooling to room temperature, then performing ultrasonic impact treatment on the repaired parts of the aluminum alloy parts, and finally machining the aluminum alloy parts; S6. Use damaged hinge parts and intact hinge parts to verify the repair process: The damaged hinge part is repaired according to steps S1 to S5. After the repair, the mandrel (7) is inserted into the multi-segment discontinuous ring of the high-strength steel hinge (15) and the multi-segment discontinuous ring of the damaged hinge part (1) to form a tensile specimen assembly. The upper clamping section of the universal testing machine clamps the upper flat plate area of ​​the high-strength steel hinge (15), and the lower clamping section of the universal testing machine clamps the lower flat plate area of ​​the repaired damaged hinge part (1). The maximum tensile force is tested. If the average value of the maximum tensile force of the repaired damaged hinge part reaches more than 97% of the average value of the maximum tensile force measured for the intact hinge part, it indicates that the above-mentioned repair process is feasible.

2. The laser additive repair method for 2B06 aluminum alloy hinge parts according to claim 1 is characterized in that: The step S1 of removing surface oil stains is to clean the surface of the aluminum alloy with ethanol or acetone.

3. The laser additive repair method for 2B06 aluminum alloy hinge parts according to claim 1 is characterized in that: The aluminum alloy powder of step S2 is specifically AlMnSc, and its specific composition is as follows: Mn: 3-6%, Mg: 1-2%, Sc: 0.5-1%, and the balance Fe. The particle size of the aluminum alloy powder is 53-150 μm.

4. The laser additive repair method for 2B06 aluminum alloy hinge parts according to claim 3 is characterized in that: The aluminum alloy powder is prepared by vacuum induction melting gas atomization or rotating disk atomization, and the drying temperature is 100-120° C. and the drying time is 2-4 hours.

5. The laser additive repair method for 2B06 aluminum alloy hinge parts according to claim 1 is characterized in that: The specific installation steps of step S31 are as follows: The fixed heat sink (3) has a semicircular groove (4) for fitting the multi-section discontinuous circular ring portion of the damaged hinge part; A left groove (5) and a right groove (6) are provided in the middle of the fixed heat dissipation block (3); The upper end of the C-type clamp (8) to (13) is pressed on the damaged hinge part (1), and the lower end extends into the left groove (5) or the right groove (6). The C-type clamp (8) to (13) is used to fix the damaged hinge part (1); Inserting the mandrel (7) into the hole of the discontinuous circular ring in multiple sections to control the deformation of the multiple discontinuous circular ring of the hinge part (1); The material of the fixed heat dissipation block (3) is aluminum bronze, and the material of the core rod (7) is high-strength steel.

6. The laser additive repair method for 2B06 aluminum alloy hinge parts according to claim 1 is characterized in that: The laser power of step S32 is 2kW-4kW, the spot diameter is 2-3mm, the moving speed is 5-15mm / s, the powder barrel speed is 1-2r / min, and the protective gas and powder feeding gas are argon.

7. The laser additive repair method for 2B06 aluminum alloy hinge parts according to claim 6 is characterized in that: The powder delivery gas flow rate is 2-5L / min, the protective gas flow rate is 5-20L / min, the overlap rate is 40%-60%, and the lifting amount of each layer is 0.5-0.8mm.

8. The laser additive repair method for 2B06 aluminum alloy hinge parts according to claim 7 is characterized in that: The laser beam is at an angle of 100°-110° to the laser moving direction. After each cladding layer, the repaired surface is polished with a grinding head.

9. The laser additive repair method for 2B06 aluminum alloy hinge parts according to claim 8, characterized in that: During the cladding process, the temperature of the parts is monitored in real time. When the temperature rises above 50°C, cladding is stopped and cladding is continued after cooling.

10. The laser additive repair method for 2B06 aluminum alloy hinge parts according to claim 1, characterized in that: In the step S5, the ultrasonic impact treatment has an impact frequency of 10000-20000 Hz, the impact head is an aluminum head, and continuous and uniform ultrasonic impact is performed 2-3 times.

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