Aluminum alloy swing laser-vibration-hot wire synergistic efficient additive method

Abstract

The application discloses a kind of aluminum alloy swing laser-vibration-hot wire synergic high-efficiency additive methods, belong to the technical field of laser melting wire additive manufacturing, including removing the oxide film and dirt on the surface of substrate;Start swing laser-vibration-synergic additive equipment, adjust the angle and position of laser and wire feeder, set additive parameters;Fix the substrate, program the robot, set the additive heat source walking route, and move the robot to the initial position;Start hot wire device to preheat welding wire;Turn on the additive heat source and protection gas switch, and add according to the programmed trajectory;After completing a layer of additive wall, clean the surface oxide, reset the robot programming track, and start the next layer of additive after the additive wall cools down;After completing the manufacture of additive wall, turn off swing laser-vibration-hot wire synergic additive equipment.The application can improve the forming precision of additive wall.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of laser fused wire additive manufacturing, and particularly relates to an aluminum alloy swing laser-vibration-hot wire synergistic efficient additive method. BACKGROUND

[0002] Aluminum alloy has high specific strength, small density and good corrosion resistance, and is widely used in the fields of aerospace, rail transportation, automobile manufacturing, medical devices and the like. In order to respond to the requirement of lightweight manufacturing, the manufacturing technology of lightweight materials represented by aluminum alloy gradually replaces the steel material. As an emerging forming technology, the aluminum alloy additive manufacturing technology at home and abroad at present mainly has laser, electric arc, electron beam, ultrasonic wave and stirring friction and the like heat source providing modes. Laser has high energy density and low heat input, and has greater advantages in high-precision forming compared with electric arc and electron beam. Laser fused wire additive manufacturing technology takes laser as a heat source, and deposits materials in a manner of melting welding wire layer by layer. Laser is a high-energy beam, and its energy is concentrated, so that the droplet transfer process determines the quality of light-wire coupling, and the stability of the deposition process has an important influence on the forming quality of the additive parts. In addition, due to the low density and poor flowability of aluminum alloy, the stability of wire feeding is also required to be higher.

[0003] For example, patent No. CN201911171055.8 proposes a laser scanning-vibration hot wire TIG composite welding method, the welding wire is reciprocated to generate a vibration hot wire, and the welding efficiency is improved by preheating the welding wire, but the vibration precision of the hot wire is not high, and it is not suitable for the additive manufacturing process with high forming quality requirement. For example, patent No. CN201811000355.5 proposes a magnetic hot wire swing laser welding device, method and application, the feeding mode of the hot wire is changed by applying an external magnetic field, but it is not effectively coupled with the swing laser, and cannot well inhibit defects and improve efficiency. SUMMARY

[0004] The present application provides an aluminum alloy swing laser-vibration-hot wire synergistic efficient additive method aiming at the deficiencies of the prior art, in order to improve the forming precision of the additive wall body, swing laser and welding wire vibration are introduced to cooperatively control droplet transfer, the accurate regulation and control of the welding wire vibration direction and amplitude are realized, and the deposition material spreading width regulation is realized through the transverse swing of the wire feeding head.

[0005] The technical scheme for solving the above technical problems is as follows:

[0006] An aluminum alloy swing laser-vibration-hot wire synergistic efficient additive method, comprising the following steps:

[0007] S1: removing the oxide film and oil stains on the surface of the aluminum alloy substrate;

[0008] S2: Starting the oscillating laser-vibration-synergistic additive equipment, adjusting the angle and position of the laser and the wire feeder, and setting the additive parameters, wherein the additive parameters include shielding gas flow, travel speed, wire feed speed, laser power, oscillating laser frequency, oscillating laser amplitude, hot wire current, hot wire voltage, and mechanical vibration amplitude and frequency;

[0009] S3: Fix the substrate, program the robot according to the substrate position, set the additive heat source walking path, and move the robot to the initial position;

[0010] S4: starting the hot wire device in the oscillating laser-vibration-synergistic additive equipment to preheat the welding wire;

[0011] S5: Turn on the additive heat source and protective gas switch, and perform additive manufacturing according to the programmed trajectory;

[0012] S6: After completing one layer of additive wall, clean the oxide on the surface of the additive wall, reset the robot programming trajectory, wait for the additive wall to cool down, repeat S5 and start the next layer of additive;

[0013] S7: After the manufacturing of the additive wall is completed, the oscillating laser-vibration-hot wire collaborative additive equipment is turned off.

[0014] Furthermore, the oscillating laser-vibration-hot wire collaborative additive equipment includes a laser and a scanning galvanometer, a galvanometer focusing device, a numerical control system, a hot wire device, a wire feeding device, a vibration device and a water cooler; wherein:

[0015] The laser, scanning galvanometer and galvanometer focusing device are used to generate the oscillating laser beam;

[0016] The CNC system is used to control the welding gun and the oscillating laser travel;

[0017] The hot wire device is used to heat the welding wire;

[0018] The wire feeding device is connected to the welding gun and is used to feed the welding wire;

[0019] The vibration device is installed on the welding gun to make the welding wire vibrate;

[0020] Water chillers are used for the cooling cycle of additive systems.

[0021] Furthermore, the hot wire device includes a hot wire power supply, the positive and negative poles of which are respectively connected to the wire feeding head and the additive platform. The welding wire extending out of the wire feeding head generates resistance heat. Before starting the droplet transfer process, the preheating temperature is set by applying the current and voltage to the conductive nozzle and the welding wire is preheated below the melting point temperature of the welding wire. The preheating current is controlled at 80-200A, and the preheating voltage is controlled at 6-10V.

[0022] Furthermore, by controlling the mechanical vibration and oscillating laser parameters, the force input during the droplet transition in the additive process can be jointly controlled; wherein, the force on the droplet during the growth and shedding process includes gravity F g , surface tension F γ , plasma flow force F p , electromagnetic force F m , Metal vapor force F rl , laser force F l , mechanical force F2, among which gravity, plasma flow force, electromagnetic force, laser force and mechanical force promote the shedding of molten droplets, while surface tension and metal vapor reaction force hinder the shedding of molten droplets.

[0023] Furthermore, gravity F g , surface tension F γ , plasma flow force F p , electromagnetic force F m , Metal vapor force F rl The expression is as follows:

[0024]

[0025] Where r d is the droplet radius, ρ is the droplet density, and g is the acceleration due to gravity;

[0026] F γ =2πr s γk;

[0027] Where r s is the wire radius, γ is the surface tension coefficient, and k is the constant coefficient;

[0028]

[0029] Where C p is the plasma flow coefficient, ρ p is the arc plasma density, K is the proportionality factor, and I is the welding current;

[0030]

[0031] Where μ is the magnetic permeability, θ is the half angle of the arc coverage area, and r s is the wire radius;

[0032]

[0033] Where R h is the metal vapor distribution coefficient, C D is the flow resistance coefficient, A is the vertical flow plane projection area, v0 is a constant, N A is Avogadro's constant, K Bis the Boltzmann constant, T S is the melting temperature of the metal, M α is the molecular mass of the gas, and B is the melt evaporation constant.

[0034] Furthermore, the resultant force F along the wire extension direction that promotes the droplet to fall off is as follows:

[0035] F=F g cosα+F p +F m +F1′+F2-F γ -F rl cosα;

[0036] Where α is the angle between the wire elongation direction and the vertical direction, and F′1 is the component of the laser force along the wire feeding direction.

[0037] Furthermore, the critical size of the droplet shedding is used to measure the amount of filler metal deposited. The mass of the metal that falls into the molten pool is given by the following formula:

[0038] m=ρv m πr s 2 =ρv s A;

[0039] Where, v m is the wire feeding speed, v s is the walking speed, and A is the cross-sectional area of ​​the sediment layer.

[0040] Furthermore, the vibration device includes a vibration power supply, a transverse vibration device and a longitudinal vibration device; the transverse vibration device is connected to the welding gun through a fixing device, driving the wire feeding head to vibrate at high frequency, so that the welding wire vibrates at high frequency; the longitudinal vibration device vibrates the wire feeding head along the vibration rod through a buffer spring.

[0041] Furthermore, the angle between the axis of the laser beam and the direction of additive travel is controlled at 80°-85°, the angle between the axis of the laser beam and the axis of the wire feeder is 20°-75°, and the welding wire is located below the laser beam; the laser beam is emitted by a laser.

[0042] Furthermore, the length of the welding wire extending from the end of the wire feeding head is maintained at 20 mm.

[0043] In summary, compared with the prior art, the above technical solution has the following beneficial effects:

[0044] (1) The hot wire system preheats the welding wire, which effectively reduces the heat input during the additive process and improves the deposition efficiency compared to the case without the hot wire system. The heat input of the additive process is controlled by adjusting the hot wire power supply and swinging the laser energy, thereby controlling the welding wire melting speed and affecting the droplet transfer frequency.

[0045] (2) Adopt high frequency vibration perpendicular to the welding wire feeding direction (elongation direction), accelerate the droplet drop, improve the additive efficiency; adopt the joint action of swing laser and mechanical vibration along the wire feeding direction, achieve the droplet drop position control, realize the position consistency of droplet transition, thereby guarantee the side wall precision of additive forming. And can realize the transition frequency and volume control of the smallest mass transfer unit (droplet) in the additive process, realize high frequency small particle transition, reduce spatter, guarantee the stability of droplet transition. BRIEF DESCRIPTION OF DRAWINGS

[0046] Figure 1 It is the overall structure schematic diagram of the embodiment of the application;

[0047] Figure 2 It is the schematic diagram of the transverse vibration device of the embodiment of the application;

[0048] Figure 3 It is another angle schematic diagram of the transverse vibration device of the embodiment of the application;

[0049] Figure 4 It is the schematic diagram of the longitudinal vibration device of the embodiment of the application;

[0050] Figure 5 It is the comparison diagram of swing laser-vibration-heat wire and conventional laser melting wire in the embodiment of the application.

[0051] The figure mark explanation: 1, base plate; 2, additive wall; 3, swing laser beam; 4, laser and scanning galvanometer; 5, galvanometer focusing device; 6, numerical control system; 7, heat wire device; 8, wire feeding device; 9, wire feeding head; 10, transverse vibration device; 101, fixing device; 102, fastening screw; 103, transverse vibration motor; 11, longitudinal vibration device; 111, longitudinal vibration motor; 112, buffer spring; 113, vibration rod; 12, fastening device; 13, vibration power supply; 14, welding wire. DETAILED DESCRIPTION

[0052] The principles and characteristics of the application are described below in combination with all the drawings, and the examples are only used to explain the application, and not to limit the scope of the application.

[0053] The embodiment of the application discloses a kind of swing laser-vibration-heat wire collaborative high-efficiency additive methods of aluminum alloy.

[0054] Common droplet transition regulation means includes adjusting heat source input waveform, applying additional energy field etc.. The stability of droplet transition process affects the spatter occurrence and additive forming of additive process. When welding wire melting and droplet transition process are unstable, it will impact the stability of molten pool flow and spoon hole, thereby leading to molten pool fluctuation, and finally affecting production efficiency.

[0055] In the additive manufacturing process of the present invention, the use of cold filaments as the deposition material requires a high additive energy input, resulting in low deposition efficiency. Hot filaments are a common optimization method for fuse additive manufacturing. Currently, common hot filament heating methods include arc heating, direct resistance heating, and high-frequency induction heating. For laser fuse additive manufacturing technology, direct resistance heating is used. By adjusting the ratio of hot filament power supply energy input to additive heat source energy input, the total energy input can be precisely controlled, effectively improving deposition efficiency and bonding performance with the substrate.

[0056] The stability of the droplet transfer process influences spatter generation and additive manufacturing during the additive manufacturing process. Unstable wire melting and droplet transfer can impact the melt pool flow and keyhole stability, causing melt pool fluctuations and ultimately impacting production efficiency. Common methods for regulating droplet transfer include adjusting the heat source input waveform and applying an additional energy field.

[0057] In order to improve the forming accuracy of the additive wall, the present invention introduces oscillating laser and welding wire vibration to collaboratively control the molten droplet transfer, thereby achieving precise control of the welding wire vibration direction and amplitude, and at the same time achieving the control of the spreading width of the deposited material through the lateral swing of the wire feeding head.

[0058] Reference Figures 1-5 , a method for aluminum alloy oscillating laser-vibration-hot wire collaborative high-efficiency material addition, comprising the following steps:

[0059] S1: removing the oxide film and oil stains on the surface of the aluminum alloy substrate 1;

[0060] S2: Start the oscillating laser-vibration-synergistic additive device, adjust the angle and position of the laser and the wire feed head 9, and set the additive parameters, which include shielding gas flow, travel speed, wire feed speed, laser power, oscillating laser frequency, oscillating laser amplitude, hot wire current, hot wire voltage, and mechanical vibration amplitude and frequency;

[0061] S3: Fix substrate 1, program the robot according to the position of substrate 1, set the additive heat source walking route, and move the robot to the initial position;

[0062] S4: starting the hot wire device 7 in the oscillating laser-vibration-synergistic additive device to preheat the welding wire 14;

[0063] S5: Turn on the additive heat source and protective gas switch, and perform additive manufacturing according to the programmed trajectory;

[0064] S6: After completing a layer of additive wall 2, clean the oxide on the surface of the additive wall 2, reset the robot programming trajectory, wait for the additive wall 2 to cool down, repeat S5, and start the next layer of additive;

[0065] S7: After the manufacturing of the additive wall 2 is completed, the swing laser-vibration-hot wire synergistic additive device is turned off.

[0066] The following will be expanded on each step:

[0067] S1: Remove the oxide film and oil stains on the surface of the aluminum alloy substrate 1.

[0068] Specifically, before the test, the surface oxide film of the aluminum alloy substrate 1 is removed by a sander, and ethanol and acetone are used to remove the surface oil stains.

[0069] S2: Start the swing laser-vibration-synergistic additive device, adjust the angle and position of the laser and the wire feeder 9, set the additive parameters, including the protective gas flow, the walking speed, the wire feeding speed, the laser power, the swing laser frequency, the swing laser amplitude, the hot wire current, the hot wire voltage, and the mechanical vibration amplitude and frequency.

[0070] Specifically, the swing laser-vibration-hot wire synergistic additive device includes a laser and a scanning galvanometer 4, a galvanometer focusing device 5, a numerical control system 6, a hot wire device 7, a wire feeding device 8, a vibration device, and a water cooler.

[0071] The laser emits a laser beam, the included angle between the laser beam axis and the additive walking direction is controlled at 80°-85°, the included angle between the laser beam axis and the axis of the wire feeder 9 is 20°-75°, the welding wire 14 is located below the laser beam, and the length of the welding wire 14 extending from the end of the wire feeder 9 is kept at 20mm. The power of the laser beam is controlled at 2-4kW, and the walking speed is controlled at 0.3-3m / min.

[0072] Among them, the vibration device is a mechanical vibration, including a vibration power supply 13, a transverse vibration device 10 and a longitudinal vibration device 11; the vibration of the transverse vibration device 10 is driven by a transverse vibration motor 103, and the fixing device 101 is fixed on the wire feeder 9 by a fastening screw 102, the transverse vibration device 10 is connected with the welding gun through the fixing device 101, and the wire feeder 9 is driven to vibrate at high frequency, so that the welding wire 14 vibrates at high frequency; the longitudinal vibration device 11 vibrates along the vibration rod 113, and the wire feeder 9 is vibrated by the buffer spring 112, and the vibration of the vibration rod 113 is driven by the longitudinal vibration motor 111.

[0073] S4: Start the hot wire device 7 in the swing laser-vibration-synergistic additive device to preheat the welding wire 14.

[0074] Specifically, the diameter of the welding wire 14 is 1.2 mm. The hot wire device 7 includes a hot wire power supply, the positive and negative electrodes of which are connected to the wire feed head 9 and the additive platform, respectively. The portion of the welding wire 14 extending from the wire feed head 9 generates resistance heat. Before the droplet transfer process begins, the preheating temperature is set by applying a current and voltage to the contact tip. The welding wire 14 is preheated below its melting point. The preheating current is controlled within a range of 80-200 A, and the preheating voltage is controlled within a range of 6-10 V.

[0075] S5: Turn on the additive heat source and protective gas switch, and perform additive manufacturing according to the programmed trajectory.

[0076] Specifically, when the shielding gas switch is turned on, shielding gas is released. The shielding gas is 99.9% argon at a flow rate of 20-25 L / min. During the additive process, the transverse vibrator 10 is directly connected to the welding gun via a fixture 101, driving the wire feeder 9 to vibrate at high frequencies, thereby causing the welding wire 14 to vibrate at high frequencies. The longitudinal vibrator 11 vibrates the wire feeder 9 along a vibrating rod 113 via a buffer spring 112.

[0077] S6: After completing a layer of additive wall 2, clean the oxide on the surface of the additive wall 2, reset the robot programming trajectory, wait for the additive wall 2 to cool down, repeat S5, and start the next layer of additive.

[0078] Specifically, after completing one layer of the additive wall 2, a wire brush is used to clean the oxide on the surface of the additive wall 2, and the robot programming trajectory is reset. After the additive wall 2 cools down, S5 is repeated to start the next layer of additive.

[0079] The hot wire system preheats the welding wire 14, effectively reducing heat input during the additive process and improving deposition efficiency compared to a process without the hot wire system. By adjusting the hot wire power supply and oscillating the laser energy, the heat input during the additive process is controlled, thereby controlling the melting rate of the welding wire 14 and influencing the droplet transfer frequency.

[0080] By controlling the mechanical vibration and oscillating laser parameters, the force input during the droplet transfer in the additive process can be jointly controlled. The welding wire is heated and melted by the combined heat input of the wire preheating and the laser energy input. When the droplet grows to a certain size, it reaches the necking stage under the action of the force and begins to fall off. The forces acting on the droplet during the growth and fall-off process mainly include: gravity F g , surface tension F γ , plasma flow force F p , electromagnetic force F m , Metal vapor force F rl , laser force F l , mechanical force F2, among which gravity, plasma flow force, electromagnetic force, laser force and mechanical force promote the shedding of molten droplets, while surface tension and metal vapor reaction force hinder the shedding of molten droplets.

[0081] Further, the gravity F g , surface tension F γ , plasma flow force F p , electromagnetic force F m , metal vapor force F rl are expressed as follows:

[0082]

[0083] where r d is the droplet radius, p is the droplet density, and g is the acceleration of gravity;

[0084] F γ = 2πr s γk;

[0085] where r s is the wire radius, γ is the surface tension coefficient, and k is a constant coefficient;

[0086]

[0087] where C p is the plasma flow force coefficient, p p is the arc plasma density, K is a proportional factor, I is the welding current, and r d is the droplet radius;

[0088]

[0089] where μ is the magnetic permeability, θ is the half angle of the arc coverage area, I is the welding current, r d is the droplet radius, and r s is the wire radius;

[0090]

[0091] where R h is the metal vapor distribution coefficient, C D is the flow resistance coefficient, A is the projected area of the vertical flow plane, v0 is a constant, N A is Avogadro's number, K B is the Boltzmann constant, T S is the metal melting temperature, M α is the gas molecular mass, and B is the melt evaporation constant.

[0092] Further, the force F promoting the droplet detachment along the wire elongation direction is as follows:

[0093] F = F g cos α + F p + F m+F1′+F2-F γ -F rl cosα;

[0094] Where α is the angle between the wire elongation direction and the vertical direction, and F′1 is the component of the laser force along the wire feeding direction.

[0095] Furthermore, the critical size of the droplet shedding is used to measure the amount of filler metal deposited. The mass of the metal that falls into the molten pool is given by the following formula:

[0096] m=ρv m πr s 2 =ρv s A;

[0097] Where, v m is the wire feeding speed, v s is the walking speed, and A is the cross-sectional area of ​​the sediment layer.

[0098] When the non-oscillating laser-vibration-hot wire collaborative additive system is added, during the deposition process, the molten metal at the end of the welding wire 14 approaches a spherical shape under the action of the combined force. The molten droplet will only fall off from the end of the welding wire 14 and transition to the molten pool when it grows to a size close to or larger than the size of the end of the welding wire 14. When the combined force reaches a level sufficient to cause the droplet to fall off from the end of the welding wire 14, the critical mass of the droplet falling off is m1. At this time, due to the large size of the droplet, the momentum of transition to the molten pool is large, and it is easy to cause the molten pool to oscillate violently when entering the molten pool, causing serious spatter. In addition, the droplet transition cycle required for the droplet to fall off is long, so the side walls of the resulting thin-walled wall are rough and the forming is not dense.

[0099] In order to reduce the oscillation and spattering of the molten pool and control the forming wall and forming accuracy, it is necessary to regulate the droplet transfer process. After adding the swing laser-vibration-hot wire collaborative additive system, during the droplet growth in the additive process, the swing laser acts on the molten metal along the swing path. With the increase of heat input and the high-frequency micro-vibration of the welding wire 14 perpendicular to the feeding direction of the welding wire 14, the droplet gradually grows along the elongation direction of the welding wire 14. When the droplet grows to a certain size, at a droplet mass of m2 (m2 <m1)时,达到颈缩阶段。此时由于熔滴过渡频率和摆动激光摆动频率、沿焊丝14送进方向的机械振动频率在时间上相位匹配,摆动激光沿行走路径刚好作用于颈缩区域,熔滴受到突然增加的激光作用力和沿焊丝14送进方向的机械振动力的共同作用。相比于无摆动激光-振动-热丝协同增材系统时,此时施加在熔滴上的沿焊丝14送进方向的合力F增大。熔滴受到的促进脱落的合力大于阻碍脱落的合力,此时沿焊丝14送进方向的合力F促进熔滴脱落。

[0100] The droplet shedding control is achieved by matching the droplet transition frequency with the oscillating laser and mechanical vibration frequency along the feed direction of the welding wire 14. With the addition of the oscillating laser and mechanical vibration of the welding wire 14 along the feed direction of the welding wire 14, droplet shedding is accelerated compared to the laser fuse additive process without oscillating laser and mechanical vibration. At this time, the oscillating laser and mechanical vibration cycles corresponding to a droplet transition cycle are controlled, and the droplet transition frequency is increased, which can achieve high-frequency transition of small particles and effectively avoid the defects of unstable forming process and low forming precision caused by low-frequency transition of large particles. In addition, by controlling the critical size of droplet shedding and the droplet transition frequency, the stability of the droplet transition is increased, achieving the control of the wall thickness and sidewall roughness of the additive wall 2.

[0101] Taking aluminum alloy as an example, the process of additive preparation using the above-mentioned aluminum alloy oscillating laser-vibration-hot wire collaborative high-efficiency additive method is explained below.

[0102] First, a 6061 aluminum alloy substrate was used as the additive manufacturing substrate. The substrate, which was 8mm thick, 150mm long, and 75mm wide, was cleaned. The surface oxide film was removed using a grinder, and ethanol and acetone were used to remove oil stains. After cleaning, it was fixed with a clamp.

[0103] The oscillating laser-vibration-hot wire collaborative additive equipment was turned on, and the experimental parameters were set as follows: laser power of 3 kW, travel speed of 1.0 m / min, wire feed speed of 1.2 m / min, laser defocus of 0 mm, circular oscillation mode, oscillation laser amplitude of 1 mm, longitudinal mechanical vibration amplitude of 2 mm, and oscillation laser frequency and longitudinal mechanical vibration frequency of 100 Hz. By adjusting the mechanical device of the KUKA robot, the angle between the wire feed head axis and the oscillating laser beam axis was adjusted to 25°, the angle between the wire feed head axis and the horizontal direction was adjusted to 70°, and the vertical distance between the wire feed head end and the substrate was adjusted to 20.5 mm.

[0104] The robot is programmed according to the position of the substrate, and a linear additive path with a length of 150 mm is set. After the teaching is completed, the robot is moved to the initial position of the path.

[0105] The hot wire device power supply was turned on, and the hot wire parameters were adjusted to preheat the welding wire. The hot wire current was 150 A and the hot wire voltage was 8 V. The deposition material was ZL205A aluminum alloy, and the welding wire diameter was 1.2 mm.

[0106] Turn on the shielding gas switch and use 99.99% pure argon as the shielding gas at a shielding gas flow rate of 25L / min. Simultaneously, turn on the oscillating laser, wire feed system, and vibrator, and perform additive manufacturing according to the programmed trajectory. After reaching the programmed endpoint, turn off the oscillating laser, wire feed system, and vibrator, and turn off the shielding gas.

[0107] After completing a layer of additive wall, use a wire brush to clean the surface oxides. Raise the robot's level according to the layer height, select the opposite direction of the previous layer, and reset the robot's programmed trajectory. After the additive wall cools, start the next layer again.

[0108] After the manufacturing of the additive wall is completed, the additive wall is removed and the oscillating laser-vibration-hot wire collaborative additive equipment is turned off.

[0109] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A highly efficient aluminum alloy additive method using oscillating laser, vibration and hot wire synergy, characterized in that: The following steps are involved: S1: removing the oxide film and oil stains on the surface of the aluminum alloy substrate (1); S2: starting the oscillating laser-vibration-synergistic additive device, adjusting the angle and position of the laser and the wire feed head (9), and setting additive parameters, wherein the additive parameters include shielding gas flow, travel speed, wire feed speed, laser power, oscillating laser frequency, oscillating laser amplitude, hot wire current, hot wire voltage, and mechanical vibration amplitude and frequency; S3: Fix the substrate (1), program the robot according to the position of the substrate (1), set the additive heat source walking route, and move the robot to the initial position; S4: starting the hot wire device (7) in the oscillating laser-vibration-synergistic additive device to preheat the welding wire (14); S5: Turn on the additive heat source and protective gas switch, and perform additive manufacturing according to the programmed trajectory; S6: After completing one layer of the additive wall (2), clean the oxide on the surface of the additive wall (2), reset the robot programming trajectory, wait for the additive wall (2) to cool down, repeat S5, and start the next layer of additive; S7: After the manufacturing of the additive wall (2) is completed, the oscillating laser-vibration-hot wire collaborative additive device is turned off; By controlling the mechanical vibration and oscillating laser parameters, the force input during the droplet transition in the additive process can be jointly controlled; the forces acting on the droplet during its growth and shedding process include gravity F g , surface tension F γ , plasma flow force F p , electromagnetic force F m , Metal vapor force F rl , laser force F l , mechanical force F2, among which gravity, plasma flow force, electromagnetic force, laser force and mechanical force promote the droplet shedding, while surface tension and metal vapor reaction force hinder the droplet shedding; Gravity F g , surface tension F γ , plasma flow force F p , electromagnetic force F m , Metal vapor force F rl The expression is as follows: ； Where r d is the droplet radius, ρ is the droplet density, and g is the acceleration due to gravity; ； Where r s is the wire radius, γ is the surface tension coefficient, and k is the constant coefficient; ； Where C p is the plasma flow coefficient, ρ p is the arc plasma density, K is the proportionality factor, and I is the welding current; ； Where μ is the magnetic permeability, θ is the half angle of the arc coverage area, and r s is the wire radius; ； Where R h is the metal vapor distribution coefficient, C D is the flow resistance coefficient, A is the vertical flow plane projection area, v0 is a constant, N A is Avogadro's constant, K B is the Boltzmann constant, T S is the melting temperature of the metal, M α is the molecular mass of the gas, B is the melt evaporation constant; The resultant force F along the wire elongation direction that promotes the droplet to fall off is as follows: ； Where α is the angle between the wire extension direction and the vertical direction, It is the component of the laser force along the wire feeding direction; The critical size of the droplet is used to measure the amount of filler metal deposited. The mass of the metal that falls into the molten pool is as follows: ； Where, v m is the wire feeding speed, v s is the walking speed, and A is the cross-sectional area of ​​the sediment layer.

2. The aluminum alloy oscillating laser-vibration-hot wire collaborative high-efficiency additive method according to claim 1, characterized in that: The oscillating laser-vibration-hot wire collaborative additive equipment includes a laser and a scanning galvanometer, a galvanometer focusing device, a numerical control system, a hot wire device, a wire feeding device, a vibration device and a water cooler; wherein: The laser, scanning galvanometer and galvanometer focusing device are used to generate the oscillating laser beam; The CNC system is used to control the welding gun and the oscillating laser travel; The hot wire device is used to heat the welding wire; The wire feeding device is connected to the welding gun and is used to feed the welding wire; The vibration device is installed on the welding gun to make the welding wire vibrate; Water chillers are used for the cooling cycle of additive systems.

3. The aluminum alloy oscillating laser-vibration-hot wire collaborative high-efficiency additive method according to claim 2, characterized in that: The hot wire device (7) includes a hot wire power supply, the positive and negative electrodes of which are respectively connected to the wire feed head (9) and the additive platform. The welding wire (14) extending from the wire feed head (9) generates resistance heat. Before the droplet transfer process begins, the preheating temperature is set by applying a current and a voltage to the conductive nozzle and the welding wire (14) is preheated below the melting point of the welding wire (14). The preheating current is controlled at 80-200 A, and the preheating voltage is controlled at 6-10 V.

4. The aluminum alloy oscillating laser-vibration-hot wire collaborative high-efficiency material addition method according to claim 2, characterized in that: The vibration device comprises a vibration power supply (13), a transverse vibration device (10) and a longitudinal vibration device (11); the transverse vibration device (10) is connected to the welding gun through a fixing device (101), driving the wire feeding head (9) to vibrate at high frequency, so that the welding wire (14) vibrates at high frequency; the longitudinal vibration device (11) vibrates the wire feeding head (9) along a vibration rod (113) through a buffer spring (112).

5. The aluminum alloy oscillating laser-vibration-hot wire collaborative high-efficiency additive method according to claim 1, characterized in that: The angle between the axis of the laser beam and the direction of the additive travel is controlled at 80-85 degrees, the angle between the axis of the laser beam and the axis of the wire feed head (9) is 20-75 degrees, and the welding wire (14) is located below the laser beam; the laser beam is emitted by a laser.

6. The aluminum alloy oscillating laser-vibration-hot wire collaborative high-efficiency material addition method according to claim 2, characterized in that: The length of the welding wire (14) extending from the end of the wire feeder (9) is maintained at 20 mm.

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