Method for repairing beryllium-aluminum alloy casting through laser cladding

Abstract

The invention belongs to the technical field of beryllium aluminum alloy casting repairing, and discloses a method for repairing a beryllium aluminum alloy casting through laser cladding. Cleaning the surface of the beryllium-aluminum alloy casting; beryllium aluminum alloy powder is selected as welding flux; preheating the casting and preserving heat; the casting is fixed to a positioner, and the laser focal length is adjusted; the welding robot moves to the corresponding point position, the position of the corresponding point is recorded, and the robot movement track is planned based on the position of the corresponding point; setting laser process parameters: laser light emitting power, robot scanning speed, cladding laser head motor position, powder feeding rotating speed of a powder feeder, powder feeding gas flow, shielding gas flow and laser moving track; turning on the laser, setting the power range of the laser, and enabling the laser to be in a light-emitting state; and the robot starts cladding operation from the original point. According to the method, the surface casting defects of the beryllium-aluminum alloy are overcome, the laser cladding process is adopted, pits and holes in the surface of the casting are repaired, and the integrity of the shape of the beryllium-aluminum casting is ensured.

Description

Technical Field

[0001] The invention belongs to the technical field of beryllium aluminum alloy casting repair, and in particular relates to a method for repairing beryllium aluminum casting by laser cladding. Background Art

[0002] Beryllium aluminum alloy has a wide crystallization temperature range. When casting beryllium aluminum alloy devices, pits and holes are prone to appear on the surface of the casting. Effectively suppressing the occurrence of shrinkage defects in the casting is a problem that needs to be solved. Laser cladding technology refers to placing the selected coating material on the surface of the coated substrate in different filler forms, melting it and a thin layer on the substrate surface at the same time through laser irradiation, and quickly solidifying to form a surface coating with extremely low dilution and metallurgical bonding with the substrate material, thereby significantly improving the wear resistance, corrosion resistance, heat resistance, and oxidation resistance of the substrate surface. Summary of the invention

[0003] The invention provides a method for repairing beryllium aluminum castings by laser cladding to correct surface casting defects of beryllium aluminum alloy.

[0004] The present invention provides a method for laser cladding repair of beryllium aluminum alloy castings, which comprises the following steps:

[0005] Clean the surface of beryllium aluminum alloy castings;

[0006] Beryllium aluminum alloy powder is selected as solder;

[0007] Preheat the casting and keep it warm;

[0008] Fix the casting on the positioner and adjust the laser focal length, which is less than or equal to 300 mm;

[0009] Make the welding robot move to the corresponding point, record the position of the corresponding point, and plan the robot motion trajectory based on the position of the corresponding point;

[0010] Set laser process parameters: laser output power, robot scanning speed, cladding laser head motor position, powder feeder powder feeding speed, powder feeding gas flow rate, shielding gas flow rate, laser running trajectory;

[0011] Turn on the laser and set the laser power range to make the laser able to emit light;

[0012] The robot starts the cladding operation from the origin. During the operation, the robot can move in 6 axes to clad the workpiece surface. After the first layer is clad, the operation is repeated for multiple layers. When all defects of the workpiece are clad, the robot is operated to return to the origin.

[0013] The repair is completed and the casting is subjected to post-weld heat treatment.

[0014] In one embodiment, the surface of the beryllium aluminum alloy casting is cleaned, which includes: removing the oxide layer and impurities on the surface of the casting by grinding, so that the metal layer is exposed on the surface of the casting.

[0015] In one embodiment, the solder is made of beryllium aluminum alloy powder with an average particle size of 40 mesh to 100 mesh, and the beryllium aluminum alloy powder is prepared by an atomization process or a plasma rotating electrode atomization process.

[0016] In one embodiment, the casting is preheated to 500-650° C. for a holding time of ≥ 2 hours.

[0017] In one embodiment, the laser running trajectory includes a preset straight line, a circle, or a square.

[0018] In one embodiment, the maximum power of the laser is 6KW.

[0019] In one embodiment, the post-weld heat treatment process is specifically as follows: preheat the casting to 400-600°C, keep it at this temperature for 2-24 hours, cool it down to 100°C at a rate of 100-200°C / h, and remove the casting after power off.

[0020] The present invention adopts a laser cladding process to repair pits and holes on the surface of the casting and ensure the integrity of the shape of the beryllium aluminum casting. DETAILED DESCRIPTION

[0021] The present invention provides a method for laser cladding repair of beryllium aluminum alloy castings, and the preparation method may include the following steps:

[0022] (1) Clean the surface of beryllium aluminum alloy castings to remove the surface oxide layer and inclusions to reveal the metallic luster;

[0023] (2) Choose the appropriate solder as beryllium aluminum alloy powder.

[0024] (3) Preheat the casting to 500-650℃ and keep it warm for ≥2 hours.

[0025] (4) The casting is fixed on the positioner and the laser focal length is adjusted to not exceed 300 mm.

[0026] (5) The robot teaching pendant opens the corresponding robot program, moves the robot to the corresponding point, records the position, plans the robot's motion trajectory, and edits the welding process parameters.

[0027] (6) Set the corresponding laser process parameters: laser output power, robot scanning speed, cladding laser head motor position, powder feeder powder feeding speed, powder feeding gas flow rate, shielding gas flow rate, laser operation trajectory, the trajectory is a preset two-dimensional figure such as a straight line, circle, square, etc.

[0028] (7) Turn on the laser enable and high voltage, and the laser power range shall not exceed 6KW, so that the laser can emit light.

[0029] (8) Start the cladding operation. During the working process, the robot can move in six axes. After the first layer is clad, the operation is repeated for several layers. When all defects on the workpiece are clad, the robot is operated to return to the origin and put it in a safe position.

[0030] The casting surface is cleaned and polished to remove the surface oxide layer and inclusions. The casting surface is polished to reveal a metallic luster.

[0031] Choose the appropriate solder as beryllium aluminum alloy powder, which can be 40 mesh ≤ D 50 Beryllium aluminum powder with an average particle size of ≤100 mesh, the powder is prepared by an atomization process or a plasma rotating electrode atomization process.

[0032] The casting is fixed on the positioner and the laser focal length is adjusted. The robot teaching pendant opens the corresponding robot program, moves the robot to the corresponding point, records the position, presets the robot motion trajectory as a straight line, circle, square, etc., and edits the welding process parameters.

[0033] Set the corresponding laser process parameters: laser output power, robot scanning speed, cladding laser head motor position, powder feeder powder feeding speed, powder feeding gas flow rate, shielding gas flow rate, and laser operation trajectory.

[0034] Turn on the laser enable and high voltage to put the laser in a state where it can emit light.

[0035] Start the cladding operation. After the first layer is clad, repeat the operation. When all defects on the workpiece are clad, operate the robot to put it in a safe position.

[0036] The repair is completed and the casting is subjected to post-weld heat treatment.

[0037] Examples of the present invention are given below.

[0038] Implementation Case 1

[0039] 1. Clean the casting surface and remove the oxide layer on the surface.

[0040] 2. Choose the appropriate solder, which is 53 mesh beryllium aluminum alloy powder.

[0041] 3. Preheat the casting to 500℃ and keep it warm for 3 hours.

[0042] 4. Fix the casting on the workbench and adjust the laser focal length by 10mm.

[0043] 5. The robot teaching pendant opens the corresponding robot program, moves the robot to the corresponding point, records the position, plans the robot's motion trajectory, and edits the welding process parameters.

[0044] 6. Set the corresponding laser process parameters: laser output power 1kW, robot scanning speed, cladding laser head motor position, powder feeder powder feeding speed, powder feeding gas flow rate, shielding gas flow rate, laser operation trajectory.

[0045] 7. Turn on the laser enable and high voltage to put the laser in a state where it can emit light.

[0046] 8. Start the cladding operation. After the first layer is clad, repeat the operation. When all defects on the workpiece are clad, operate the robot to put it in a safe position.

[0047] 9. After the repair is completed, the casting is subjected to post-weld heat treatment.

[0048] Implementation Case 2

[0049] 1. Clean the casting surface and remove the oxide layer on the surface;

[0050] 2. Choose the appropriate solder powder with average particle size (D 50 )80 mesh beryllium aluminum alloy powder.

[0051] 3. Preheat the casting to 600℃ and keep it warm for 2.5 hours.

[0052] 4. Fix the casting on the workbench and adjust the laser focal length to 150mm.

[0053] 5. The robot teaching pendant opens the corresponding robot program, moves the robot to the corresponding point, records the position, plans the robot's motion trajectory, and edits the welding process parameters.

[0054] 6. Set the corresponding laser process parameters: laser output power 3kW, robot scanning speed, cladding laser head motor position, powder feeder powder feeding speed, powder feeding gas flow rate, shielding gas flow rate, laser operation trajectory.

[0055] 7. Turn on the laser enable and high voltage to put the laser in a state where it can emit light.

[0056] 8. Start the cladding operation. After the first layer is clad, repeat the operation. When all defects on the workpiece are clad, operate the robot to put it in a safe position.

[0057] 9. After the repair is completed, the casting is subjected to post-weld heat treatment.

[0058] Implementation Case 3

[0059] 1. Clean the casting surface and remove the oxide layer on the surface;

[0060] 2. Choose the appropriate solder powder with average particle size (D 50 )100 mesh beryllium aluminum alloy powder.

[0061] 3. Preheat the casting to 650℃ and keep it warm for 2 hours.

[0062] 4. Fix the casting on the workbench and adjust the laser focal length to 300mm.

[0063] 5. The robot teaching pendant opens the corresponding robot program, moves the robot to the corresponding point, records the position, plans the robot's motion trajectory, and edits the welding process parameters.

[0064] 6. Set the corresponding laser process parameters: laser output power 6kW, robot scanning speed, cladding laser head motor position, powder feeder powder feeding speed, powder feeding gas flow rate, shielding gas flow rate, laser operation trajectory.

[0065] 7. Turn on the laser enable and high voltage to put the laser in a state where it can emit light.

[0066] 8. Start the cladding operation. After the first layer is clad, repeat the operation. When all defects on the workpiece are clad, operate the robot to put it in a safe position.

[0067] 9. After the repair is completed, the casting is subjected to post-weld heat treatment.

[0068] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them. Although the present invention has been described in detail with reference to the above embodiments, it should be understood by those skilled in the art that the technical solutions described in the above embodiments can still be modified, or some or all of the technical features therein can be replaced by equivalents, and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for repairing beryllium aluminum alloy castings by laser cladding, characterized in that: It includes the following steps: Clean the surface of beryllium aluminum alloy castings; Beryllium aluminum alloy powder is selected as solder; Preheat the casting and keep it warm; Fix the casting on the positioner and adjust the laser focal length, which is less than or equal to 300 mm; Make the welding robot move to the corresponding point, record the position of the corresponding point, and plan the robot motion trajectory based on the position of the corresponding point; Set the laser process parameters, including: laser output power, robot scanning speed, cladding laser head motor position, powder feeder powder feeding speed, powder feeding gas flow rate, shielding gas flow rate, laser running trajectory; Turn on the laser and set the laser power range to make the laser able to emit light; The robot starts the cladding operation from the origin. During the operation, the robot 6 moves axially on the workpiece surface to clad. After the first layer is clad, the operation is repeated for multiple layers. When all defects of the workpiece are clad, the robot is operated to return to the origin. The repair is completed and the casting is subjected to post-weld heat treatment.

2. The method for repairing beryllium aluminum alloy casting by laser cladding according to claim 1, characterized in that: The surface of the beryllium aluminum alloy casting is cleaned, which includes: The oxide layer and impurities on the surface of the casting are removed by grinding, so that the metal layer is exposed on the surface of the casting.

3. The method for repairing beryllium aluminum alloy casting by laser cladding according to claim 1, characterized in that: The solder is made of beryllium aluminum alloy powder with an average particle size of 40 meshes to 100 meshes, and the beryllium aluminum alloy powder is prepared by a vacuum inert gas atomization process or a plasma rotating electrode atomization process.

4. The method for repairing beryllium aluminum alloy casting by laser cladding according to claim 1, characterized in that: Preheat the casting to 500-650℃ and keep it warm for ≥2 hours.

5. The method for repairing beryllium aluminum alloy casting by laser cladding according to claim 1, characterized in that: The laser running track includes a preset straight line, a circle, and a square.

6. The method for repairing beryllium aluminum alloy casting by laser cladding according to claim 1, characterized in that: The maximum power of the laser is 6KW.

7. The method for repairing beryllium aluminum alloy casting by laser cladding according to claim 1, characterized in that: The specific post-weld heat treatment process is as follows: preheat the casting to 400-600°C, keep it warm for 2-24 hours, cool it down evenly to 100°C at 100-200°C / h, and remove the casting after power off.