Laser repair system and method based on light alloy powder preheating

Abstract

The present invention relates to a laser repair system and method based on light alloy powder preheating, the system includes a fixed support structure, a laser light source, a preheating extrusion mechanism, and a powder feeding mechanism. After receiving the surface damage data of the structural part, the intelligent control host intelligently identifies the damaged area of ​​the structural part, slices it in layers, and plans the repair path and preliminary process parameters. At the same time, the powder feeding mechanism and the induction preheating device are controlled to heat and melt the required light alloy powder before the repair process begins, and the damaged area is repaired in conjunction with the laser heat source. Subsequently, the induction heating power is reduced and the laser power is increased, so as to achieve the purpose of improving the powder utilization rate in the laser repair process and improving the surface repair quality of the structural part. The present invention provides a solution for preheating powder consumables before the laser repair process begins, which effectively improves the adhesion of metal consumables on the surface of the damaged area, and provides technical support for improving the powder utilization rate in the laser repair process.

Description

[0001] Author: Zhan Xiaohong, Zhang Yumeng, Shi Bowen, Wang Leilei Technical field:

[0002] The invention relates to the technical field of powder material heat treatment and laser forming, and in particular to a laser repair system and method based on powder induction preheating. Background technology:

[0003] Repair technology based on laser melting deposition technology is now developing rapidly due to its advantages of low cost, high metallurgical bonding strength, good wear resistance and corrosion resistance. Laser melting deposition technology can be used to quickly repair damaged parts of key structural parts of engineering machinery, extend their service life and reduce scrapping costs.

[0004] However, during the laser repair process, when the powder is transported to the surface of the plate, part of the powder is still in the solid phase, so the powder utilization rate may be reduced under the thrust of the powder-carrying gas. This problem is particularly obvious in extremely cold environments. If the powder enters a semi-molten state before leaving the cladding head, the wettability of the powder and the substrate surface can be increased, thereby improving the repair quality of the damaged area, which can lay the foundation for the further promotion and utilization of laser repair technology. Summary of the invention:

[0005] In order to solve the above-mentioned problems existing in the above-mentioned background technology, the present invention proposes a laser repair system and method based on induction preheating of light alloy powder, which takes into account the technical advantages of laser cladding, powder heat treatment and composite material processing. By induction preheating the alloy powder to form an alloy fluid before the start of the laser cladding process, the wettability between the consumables and the substrate can be increased in a low temperature environment, the laser repair forming quality and service performance can be improved, and the preheating device and the laser welding device are coupled to form an integrated system, which reduces the energy consumption required by the system and enhances the operability of the system.

[0006] The technical solution of the present invention to solve the above problems is: a laser repair system based on powder induction preheating, which is special in that:

[0007] A preheating extrusion mechanism including an induction preheating mechanism and a hollow extrusion screw was designed, and the mechanism was combined with a welding machine body and a laser device to form an integrated coupling system. The system specifically includes a welding machine body, a laser light source, a rotary extrusion device, and a light alloy powder feeding mechanism.

[0008] The preheating extrusion mechanism designed in the above device is divided into a hollow extrusion screw and an induction preheating component, wherein the hollow rotating screw is composed of a hollow rotating shaft and spiral blades around the rotating shaft, and the hollow screw is fixed in the vertical direction by an upper bearing mechanism and a lower bearing mechanism. The rotational movement of the hollow screw is driven by a servo motor. The hollow servo motor is a hollow inner rotor motor, which is driven to rotate by a rotating motor and a conveyor belt outside the system, and the hollow servo motor rotor rotates through the hollow servo motor rotor keyway and the hollow main shaft spline.

[0009] The induction preheating component is mainly composed of a right linear stepper motor, fastening bolts, a rotating lead screw, a sealing gasket, a screw extrusion mechanism, a moving slider, an induction coil base, a left linear stepper motor, and an induction heating coil. The induction preheating component is set on the base platform below the ceramic base, and the ceramic sealing ring and sealing ring outside the coil strengthen the sealing between the base and the base;

[0010] Furthermore, the laser component in the repair system is located on the first support platform at the uppermost layer of the fixed support structure, and includes a laser generating device and a wireless signal receiving device. The laser device is used to realize the generation of a laser heat source, and a through hole with a diameter of 20 mm is opened in the center of the first support platform;

[0011] The fixed support structure is used to fix the laser device, the powder feeding mechanism and the induction preheating mechanism. The lower surface of the first support platform is 80mm away from the top of the welding machine and is fastened to the side wall of the welding machine body by M10 bolts. The second support platform is set at 135mm from the top and is fastened to the side wall of the welding machine body by M10 bolts. A fixed plate is set at the top of the shell structure, and an M10 threaded through hole is set on the fixed plate for connecting with the robot arm outside the system;

[0012] The light alloy powder feeding mechanism comprises a light alloy powder bin, a rotary stop valve, a powder conduit, and a rotary motor. The powder feeding mechanism is arranged above the ceramic base and is used to transport the light alloy powder to the laser repair area.

[0013] After the laser repair process begins, the rotary motor rotates clockwise to open the rotary stop valve, and the light alloy powder in the light alloy powder bin is injected into the area where the induction coil is located around the hollow screw through the powder conduit. At the same time, the opening amplitude of the stop valve can be adjusted by controlling the rotation angle of the rotary motor, thereby realizing the regulation of the powder flow rate.

[0014] In addition, in the above-mentioned laser repair system based on light alloy powder preheating, the present invention also proposes a laser repair method based on light alloy powder induction preheating, which is characterized by:

[0015] 1) Positioning preparation stage:

[0016] After detecting damage to the structural parts, the intelligent control host identifies and calculates the external dimensions of the damaged area, then reconstructs the three-dimensional structure of the damaged area, intelligently layers and plans the path, and sets preliminary laser process parameters such as defocus, laser power, and scanning rate.

[0017] 2) Light alloy powder preheating stage:

[0018] The intelligent control host calculates the amount of powder according to the morphology of the damaged area and increases the margin by 5%. After receiving the command of the intelligent control host, the wireless signal receiving device controls the rotating motor connected to it to rotate counterclockwise and drive the stop valve to open, and a sufficient amount of alloy powder in the alloy powder bin is injected into the area where the induction coil is located; before the laser repair process starts, the linear stepper motor rotates, driving the moving rod to rotate, and the hollow moving slider can move in the horizontal direction close to the center of the longitudinal axis, and close the lower channel before the laser repair process starts to prevent the powder from overflowing before the heating stage is completed; the linear stepper motor controls the moving slider to close the powder leaving channel under the induction coil; at this time, current is passed into the induction coil, and the voltage and current in the coil are adjusted by the power adjustment device, so as to control the strength of the magnetic field and the heating power; in addition, the servo motor connected to the hollow screw starts to drive the screw to rotate at a high speed, and the spiral groove on the surface of the screw stirs the metal melt and a small amount of unmelted powder; after 30 seconds, until all the light alloy powder is turned into metal melt, the preheating process is over, and the heating power is reduced to 80% of the original power to keep the melt warm and prepare to enter the light alloy laser cladding stage.

[0019] 3) Light alloy laser repair stage:

[0020] The linear stepper motor receives the light alloy repair command sent by the intelligent control host and starts to rotate in the opposite direction, controlling the moving slider to open the powder outflow channel under the sensing area, and repairs the damaged area using the light alloy melt and laser heat source according to the set laser process parameters.

[0021] Furthermore, in step 1), the welding machine is first placed vertically above the damaged area, and the distance between the welding machine and the substrate surface is within 5 mm, which can effectively reduce the interaction area between the melt and the outside world;

[0022] Furthermore, the wireless signal receiving device is connected to the laser light source, the powder feeding mechanism, and the induction coil device;

[0023] Furthermore, the powder feeding mechanism can not only feed powder individually, but also feed powder simultaneously and control the powder mixing ratio to print gradient materials by controlling the gear speed;

[0024] Furthermore, the light alloy powder is TC4 powder with a particle size of 300 to 1000 meshes;

[0025] Furthermore, the induction coil base is made of insulating heat-resistant ceramics to avoid melting due to heating by the induction coil or influence of molten fluid.

[0026] Advantages of the present invention:

[0027] (1) The present invention has good forming effect and small forming force. It combines the dual advantages of induction preheating and high-energy beam heat source in the laser repair process to increase the adhesion between the powder consumables and the damaged parts, improve the wetting degree, and increase the density of the repair layer. It can improve the adaptability of the laser repair system to a lower temperature environment, further improve the powder utilization rate in the repair process and improve the surface repair quality of the structural parts, thereby further extending the service life of the repair layer of the structural parts;

[0028] (2) Preheating the powder into a melt before the laser repair process begins can reduce the energy required by the laser repair system and reduce energy consumption. Description of the drawings:

[0029] Figure 1 It is a front view of the device of the present invention;

[0030] Figure 2 is a schematic diagram of a fixed support structure;

[0031] Figure 3 It is a schematic diagram of the laser light source structure.

[0032] Figure 4 2. It is a schematic diagram of the structure of a rotary screw extruder;

[0033] Figure 5 It is a schematic diagram of the structure of a light alloy powder feeding device;

[0034] Figure 6 It is a schematic diagram of the structure of the moving slider device;

[0035] Figure 7 It is a schematic diagram of the overall structure of the induction preheating components;

[0036] In the figure:

[0037] 1. Fixed support structure, 1-1 outer frame, 1-2, first support platform, 1-3, M10 fastening bolts, 1-4, second support platform, 1-5, M10 fastening bolts, 1-6, M10 fastening bolts, 1-7, M10 fastening bolts, 1-8, M10 fastening bolts, 1-9, M10 fastening bolts,

[0038] 2. Laser light source, 2-1 laser generating device, 2-2 wireless signal receiving device, 2-3 fixing platform,

[0039] 3. Rotating screw extrusion components, 3-1. Hollow servo motor, 3-2. Hollow spindle spline, 3-3. Hollow motor rotor, 3-4. Fixed table, 3-5. Upper end bearing device, 3-6. Rotating extrusion screw, 3-7. Bearing device, 3-8. Ceramic sealing ring, 3-9. Spline keyway,

[0040] 4. Light alloy powder feeding mechanism, 4-1. Light alloy powder feeding bin, 4-2. Scraper type powder feeder, 4-3. Powder guide tube, 4-4. Horizontal bevel gear, 4-5. Vertical bevel gear, 4-6. Servo stepper motor,

[0041] 5. Induction coil base, 6. Base fastening bolt M10, 7. M6 fastening device,

[0042] 8. Moving slider device, 8-1. Linear stepper motor, 8-2. Moving rod, 8-3. Moving slider,

[0043] 9. Melt flow channel,

[0044] 10. Ceramic base platform,

[0045] 11. Induction preheating components, 11-1. AC pulse power supply, 11-2. Induction heating coil, 11-3. Wireless signal receiving device, 11-4. Metal adjustment resistor,

[0046] 12. Ceramic bushing, 13. Aerogel insulation material, 14. M16 fastening bolts, 15. M16 fastening bolts, 16. M16 fastening bolts; Specific implementation method:

[0047] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0048] Reference Figure 1 , a laser repair system based on light alloy powder induction preheating, the system is composed of four parts: a fixed support structure 1, a laser light source 2, a preheating extrusion mechanism, and a light alloy powder feeding mechanism 4;

[0049] Reference Figure 2 The fixed support structure 1 is composed of a welding machine housing 1-1, a first support platform 1-2, first support platform fastening bolts 1-3, a second support platform 1-4, second support platform fastening bolts 1-5, and an induction coil base fastening bolt 1-6. The fixed support structure 1 is used to fix the laser light source 2, the light alloy powder feeding mechanism 4 and the preheating extrusion mechanism, and is the basic support of the system;

[0050] Reference Figure 3, the laser light source 2 is mainly composed of a laser generating device 2-1, a wireless signal receiving device 2-2, and a fixing platform 2-3, and is used to generate a laser heat source;

[0051] Reference Figure 4 and Figure 5 The preheating extrusion mechanism is mainly composed of a rotating screw extrusion component 3 and an induction preheating component 11. The rotating screw extrusion component 3 mainly includes a hollow servo motor 3-1, a hollow spindle spline 3-2 and a hollow motor rotor 3-3, a fixed platform 3-4, an upper end bearing 3-5, a rotating extrusion screw 3-6, and a bearing 3-7; the induction preheating component 11 is mainly composed of a DC power supply 11-1, an inductive heating coil 11-2, a wireless signal receiving device 11-3, and a metal regulating resistor 11-4. The preheating extrusion mechanism is mainly used to heat and rotate and stir the light alloy powder before the arc additive process starts to form a uniformly heated metal melt;

[0052] Reference Figure 5 The light alloy powder feeding mechanism 4 is mainly composed of a light alloy powder feeding bin 4-1, a rotary stop valve 4-2, a powder conduit 4-3, and a rotary motor 4-4, and is used to provide a powder matrix and repair consumables for heating during the laser repair process;

[0053] Reference Figure 6 The moving slider device 8 is mainly composed of a linear stepping motor 8-1, a moving rod 8-2, and a moving slider 8-3, and is mainly used to close the melt channel under the ceramic base during the preheating stage of the light alloy powder before the laser repair process begins;

[0054] A laser repair method based on preheating of light alloy powder comprises the following steps:

[0055] 1) Positioning preparation stage: refer to Figure 1 First, the fixed support structure 1 is vertically placed above the damaged area, and the distance between the welding machine and the substrate surface is within 5 mm, which can effectively reduce the interaction area between the melt and the outside world; the intelligent control host is used to intelligently layer and plan the path of the damaged area of ​​the structural part, and set the laser process parameters;

[0056] 2) Light alloy powder preheating stage:

[0057] The intelligent control host calculates the powder dosage according to the morphology of the damaged area and increases the margin by 5%. After receiving the command from the intelligent control host, the wireless signal receiving device 3-2 controls the servo motor 4-6 connected thereto to rotate clockwise, driving the vertical bevel gear 4-5 to rotate, and at the same time driving the horizontal bevel gear 4-4 and the scraper powder feeder 4-2 to rotate clockwise, guiding a sufficient amount of alloy powder in the powder alloy bin 4-1 to be injected into the area where the induction coil device 11-2 is located through the powder conduit 4-3 at a constant feeding speed; the linear stepper motor 8-1 controls the moving slider 8-3 to close the melt flow channel 9 below the induction coil device 11-2 Closed; at this time, current is passed through the induction coil 11-2, and the voltage and current in the induction coil 11-2 are adjusted through the wireless signal receiving device 11-3 and the metal regulating resistor 11-4, so as to control the strength of the magnetic field and the heating power; in addition, the hollow servo motor 3-1 connected to the hollow screw 3-6 starts to drive the hollow screw 3-6 to rotate at a high speed, and the spiral groove on the surface of the hollow screw 3-6 stirs the metal melt and the unmelted powder; after 30 seconds, until all the light alloy powder is turned into metal melt, the preheating process is completed, and the heating power is reduced to 80% of the original power to keep the melt warm and enter the light alloy laser cladding stage;

[0058] 3) Light alloy laser repair stage:

[0059] The linear stepper motor 8-1 receives the light alloy repair instruction transmitted by the intelligent control host and starts to rotate in the reverse direction, controls the moving slider 8-3 to open the powder outflow channel below the sensing area, and repairs the damaged area using the light alloy melt and the laser heat source according to the set laser process parameters;

[0060] Obviously, the above embodiments of the present invention are only examples for clearly illustrating the present invention, and are not intended to limit the implementation methods of the present invention. It is not necessary and impossible to list all implementation methods exhaustively. The content of this specification should not be understood as limiting the present invention. For those of ordinary skill in the art, based on the idea of ​​the present invention, other different forms of changes or modifications can be made on the basis of the above description. It should be pointed out that any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the claims of the present invention.

Claims

1. A laser repair system based on light alloy powder preheating, characterized in that: It comprises a fixed support structure (1), a laser light source (2), a light alloy powder feeding mechanism (4), and a preheating extrusion mechanism; The preheating extrusion mechanism comprises a rotating screw extrusion component (3) and an induction preheating component (11); the rotating screw extrusion component (3) comprises a hollow servo motor (3-1), a hollow spindle spline (3-2), a hollow motor rotor (3-3), a second fixed platform (3-4), an upper end bearing device (3-5), a rotating extrusion screw (3-6), a bearing device (3-7), a ceramic sealing ring (3-8) and a spline keyway (3-9); and is connected to the second supporting platform (1-4) by fastening bolts on both sides, and is used to stir the light alloy melt before the laser repair process starts, so as to ensure that the metal melt can be evenly heated and melted; The fixed support structure (1) comprises an outer frame (1-1), a first support platform (1-2), a first support platform right side fastening bolt (1-3), a second support platform (1-4), a second support platform right side fastening bolt (1-5), an induction coil base right side fastening bolt (1-6), an induction coil base left side fastening bolt (1-7), a second support platform left side fastening bolt (1-8), and a first support platform left side fastening bolt (1-9), and is used to achieve the fixation of various mechanisms; The laser light source (2) in the laser repair system comprises a laser generating device (2-1) and a wireless signal receiving device (2-2), which are connected to the first supporting platform (1-2) via a first fixing platform (2-3); the wireless signal receiving device (2-2) can receive morphological information from the damaged area and instructions from the control host, and can distribute wireless control signals to various mechanisms of the repair system; The light alloy powder feeding mechanism (4) comprises a light alloy powder feeding bin (4-1), a rotary stop valve (4-2), a powder conduit (4-3), a horizontal bevel gear (4-4), a vertical bevel gear (4-5), and a servo stepping motor (4-6); The movable slider device (8) mainly comprises a linear stepping motor (8-1), a movable rod (8-2) and a movable slider (8-3), and is used to close the melt channel under the ceramic base during the light alloy powder preheating stage before the start of the laser repair process.

2. The laser repair system based on light alloy powder preheating according to claim 1 is characterized in that: The induction preheating component (11) specifically comprises an AC pulse power supply (11-1), an electromagnetic induction coil (11-2), a wireless signal receiving device (11-3), and a metal adjustment resistor (11-4); the preheating component is arranged on the upper surface of the ceramic base platform (10); and the outer layer of the induction preheating component (11) is a ceramic bushing (12) and an aerogel insulation material (13); When the device performs a powder preheating operation, the wireless signal receiving device (11-3) receives instructions to close the circuit, the induction coil (11-2) receives current and generates an alternating magnetic field, and the metal regulating resistor (11-4) receives instructions to adjust the circuit current to control the heating power.

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