A laser additive manufacturing apparatus and method for synergistic spot shape control and energy regulation

Abstract

This invention proposes a laser additive manufacturing apparatus and method with synergistic spot shape control and energy regulation, belonging to the field of additive manufacturing. A wire feeding mechanism transports wire and limits the wire to be perpendicular to the substrate surface. Several laser beams are arranged around the wire, including a first beam and a second beam. The irradiation direction of each first beam simultaneously intersects the same point on the substrate, forming a first spot. The first beam melts the wire, forming a molten pool at the location of the first spot on the substrate. The second beams irradiate the substrate, forming second spots, which are arranged around the first spots. The second spots move around the first spots or couple with them, allowing for synergistic regulation of the spot shape and energy distribution. This invention employs coaxial laser synergistic scanning to achieve dynamic adjustment and synergistic coupling of the spot shape and energy distribution during additive manufacturing, precisely controlling the shape, size, and depth of the molten pool, meeting the high-efficiency, high-precision additive manufacturing requirements for complex components.

Description

Technical Field

[0001] This invention relates to the field of additive manufacturing technology, and in particular to a laser additive manufacturing apparatus and method with synergistic spot shape control and energy regulation. Background Technology

[0002] As components in aerospace and other industries trend towards larger sizes and integration, traditional manufacturing technologies suffer from drawbacks such as long development cycles, high costs, and low material utilization. Laser additive manufacturing technology offers a new solution, boasting significant technological and economic advantages such as digitalization, precision, integrated design-materials-manufacturing, short cycles, and rapid iteration. However, current laser additive manufacturing technologies generally face the challenge of balancing forming efficiency and precision. Pursuing high manufacturing efficiency can easily lead to decreased forming accuracy, increased machining difficulty, and material waste, contradicting its technological philosophy of rapid, short-process manufacturing.

[0003] Developing corresponding melt pool shaping strategies based on the structural characteristics of different parts of a component is a key approach to solving the mismatch between forming accuracy and efficiency in laser additive manufacturing. Currently, melt pool shaping technology is widely used in laser additive manufacturing. However, for large and complex components with significant differences in wall thickness and geometry, traditional melt pool shaping technology still faces technical bottlenecks in the additive manufacturing process, particularly in coordinating spot shape control and energy regulation. This makes it impossible to meet the technical requirements of balancing forming accuracy and efficiency in the additive manufacturing of large and complex components. Summary of the Invention

[0004] In view of this, the present invention proposes a laser additive manufacturing device and method for synergistic spot shape control and energy regulation, which is used to solve the technical bottleneck of the traditional molten pool shaping technology in overcoming the difficulty of synergistic regulation of spot shape and energy distribution in the additive manufacturing process.

[0005] The technical solution of this invention is implemented as follows: This invention provides a laser additive manufacturing apparatus for coordinated spot shape control and energy regulation, including a substrate; a wire feeding mechanism disposed above the substrate and moving in a direction parallel to the substrate surface; and a laser assembly disposed above the substrate and emitting a plurality of laser beams; wherein, the wire feeding mechanism conveys the wire and defines the wire as perpendicular to the substrate surface; the plurality of laser beams are arranged around the wire, and the laser beams include a first beam and a second beam, the irradiation direction of each first beam simultaneously intersects the same point on the substrate and forms a first spot, the first beam melts the wire and forms a molten pool at the location of the first spot on the substrate; at least two second beams respectively irradiate the substrate to form second spots, each second spot is arranged around the first spot, and the second spots move around the first spot or couple with the first spot.

[0006] Based on the above technical solutions, preferably, the laser component includes a laser emitter that emits a main beam; a beam splitter that divides the main beam into several laser beams; a first galvanometer and a second galvanometer that reflect the laser beams and adjust the irradiation direction of the laser beams; and a focusing lens that focuses the laser beams and forms a spot on the substrate. The x-axis is defined as the direction along which the wire feeding mechanism moves, and the y-axis is defined as the direction perpendicular to the direction of the wire feeding mechanism, with the y-axis being the parallel direction to the substrate surface. The first galvanometer oscillates and moves the spot along the x-axis, and the second galvanometer oscillates and moves the spot along the y-axis, ultimately causing the irradiation directions of each first beam to simultaneously intersect at the same point on the substrate and form a first spot, or causing a second spot to move around the first spot.

[0007] More preferably, the movement path of each second light spot around the first light spot is an arc, the arc angle is no greater than 180°, and the starting point of the movement path of the second light spot is the center of the arc.

[0008] Even more preferably, the diameter of the second light spot is smaller than the diameter of the first light spot.

[0009] Even more preferably, the diameter of the second light spot is larger than the radius of the first light spot.

[0010] More preferably, the laser component emits n second beams, and the arc of the moving path of each second beam is not less than 360° / n.

[0011] Based on the above technical solutions, preferably, the edge of the second light spot is tangent to the edge of the first light spot.

[0012] Based on the above technical solutions, preferably, the moving speed of the second light spot is greater than the moving speed of the first light spot.

[0013] Based on the above technical solutions, preferably, the power of the second beam is not greater than the power of the first beam.

[0014] On the other hand, the present invention also provides a laser additive manufacturing method with synergistic spot shape control and energy regulation. The method employs the aforementioned laser additive manufacturing apparatus with synergistic spot shape control and energy regulation, comprising the following steps: Step 1, activating the laser assembly, which emits a first beam and a second beam, forming a first spot and a second spot on the substrate; Step 2, activating the wire feeding mechanism to feed wire onto the substrate and form a molten pool on the substrate, with a detection device positioned above the substrate to detect defects in the molten pool; Step 3, based on the defects detected by the detection device, each second spot moves around the first spot and shapes the edge of the molten pool, while the laser assembly and the wire feeding assembly move synchronously along the substrate surface and print the component, with each second spot continuously shaping the molten pool until the component is printed.

[0015] The laser additive manufacturing apparatus and method of the present invention, which combines synergistic spot shape control and energy regulation, has the following advantages over the prior art:

[0016] (1) This invention adopts coaxial laser collaborative scanning to realize the dynamic adjustment of the spot shape and the coordinated coupling of energy distribution during the additive manufacturing process. It accurately controls the molten pool characteristics such as shape, size and depth to meet the forming efficiency, accuracy and performance requirements of different structural parts of the component in the additive manufacturing process. It provides a solution to overcome the mutual constraints between efficiency and accuracy in laser additive manufacturing and promotes the development of efficient and high-precision laser additive manufacturing technology for complex metal components.

[0017] (2) This invention controls the relative movement of the second spot with respect to the first spot in the x-axis and y-axis directions by quantitatively changing the swing angle and frequency of the two galvanometers, thereby achieving directional control of the spot shape, size and energy density, that is, achieving directional synergistic coupling control of spot shape control and energy modulation. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a perspective view of the additive manufacturing apparatus of the present invention;

[0020] Figure 2 This is a schematic diagram of the structure of the laser component of the present invention;

[0021] Figure 3 This is a schematic diagram of the light spot of the present invention;

[0022] Figure 4 This is a schematic diagram of another embodiment of the light spot of the present invention.

[0023] In the figure: 1. Substrate; 11. Molten pool; 101. First spot; 102. Second spot; 2. Wire feeding mechanism; 3. Laser assembly; 31. Laser emitter; 32. Beam splitter; 33. First galvanometer; 34. Second galvanometer; 35. Focusing lens; 300. Laser beam; 301. First beam; 302. Second beam; 4. Detection device. Detailed Implementation

[0024] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0025] like Figure 1 As shown, combined with Figure 3 The present invention provides a laser additive manufacturing apparatus for coordinated spot shape control and energy regulation, comprising a substrate 1, a wire feeding mechanism 2, and a laser component 3.

[0026] Among them, the substrate 1 has a molded component, and the surface of the substrate 1 remains horizontal.

[0027] The filament feeding mechanism 2 is positioned above the substrate 1 and moves parallel to the surface of the substrate 1. The filament feeding mechanism 2 feeds the filament 21 and defines the filament 21 perpendicular to the surface of the substrate 1. It should be noted that the filament feeding mechanism 2 can also be a powder feeding mechanism or a filament-powder composite feeding mechanism, and the feeding material can be the filament 21, powder, or a filament-powder composite material. The laser assembly 3 in this application is mainly designed to work in conjunction with the filament feeding mechanism 2, so that the laser beam 300 is coaxially arranged around the filament 21. Assuming the feeding mechanism is a powder feeding mechanism, the laser beam 300 used for printing, i.e., the first beam 301, can be set to be perpendicularly directed towards the substrate 1; while the laser beam 300 used for shaping, i.e., the second beam 302, can be coaxially arranged around the first beam 301.

[0028] The laser component 3 is positioned above the substrate 1 and emits several laser beams 300. The several laser beams 300 are arranged around the filament 21.

[0029] The laser beam 300 includes a first beam 301 and a second beam 302. The irradiation directions of each first beam 301 simultaneously intersect at the same point on the substrate 1, forming a first spot 101. The first beam 301 melts the wire 21, forming a molten pool 11 at the location of the first spot 101 on the substrate 1. At least two second beams 302 respectively irradiate the substrate 1, forming second spots 102. Each second spot 102 is arranged around the first spot 101. The second spots 102 move around the first spot 101 and irradiate the edge of the molten pool 11 for shaping, or couple with the first laser 101, achieving the purpose of coordinated control of the shape and energy distribution of the spots. By employing coaxial laser coordinated scanning, dynamic adjustment of the spot shape and coordinated coupling of energy distribution are achieved during additive manufacturing, precisely controlling the molten pool characteristics such as shape, size, and depth, meeting the high-efficiency and high-precision additive manufacturing requirements of complex components.

[0030] In this embodiment, multiple first beams 301 are coaxially arranged around the filament 21, and each first beam 301 intersects at the same point, causing multiple light spots to overlap and form a first light spot 101, thus achieving cross-superposition of light spots. However, since the direction of each first beam 301 is fixed, the shape, size, and energy distribution of the coupled first light spot 101 are also fixed. This makes it difficult to meet the requirements for light spot characteristics when forming molten pools 11 with different shapes, sizes, and depths, and consequently, it cannot meet the forming efficiency, accuracy, and performance requirements of different structural parts of the component in the additive manufacturing process. The coaxial laser beam 300 in this embodiment includes not only the first beam 101 for printing the component but also a second beam 102. The second beam 102 has two functions: First, the direction of the second beam 102 is variable, so that the position of the second spot 102 formed by it can be moved on the substrate 1, thereby changing the coupling between the second spot 102 and the first spot 101. For example, the first spot 101 is usually circular, but if three second spots 102 are evenly distributed around the first spot 101, the coupled spot formed by the second spot 102 and the first spot 101 is similar to a triangle. Moreover, the arrangement of the three second spots 102 can be adjusted relative to the printing direction, thereby adapting to the forming requirements of more molten pools 11. Secondly, the second beam 302 also serves as a shaping laser. When the molten pool 11 is formed and its edges gradually spread outward and solidify, the edges of the molten pool 11 will have different defects due to factors such as printing speed, filament 21 properties, printing spot size, and energy intensity. Furthermore, the defects at different locations on the edge of the molten pool 11 will also differ. When the second spot 102 formed by the second beam 302 moves around the first spot 101, it can purposefully move to the defect location on the edge of the molten pool 11 for shaping. For example, if there is a thick protrusion on the edge of the molten pool 11, the second spot 102 can move to the protrusion and melt it, gradually flattening it and eliminating the defects in the molten pool 11.

[0031] exist Figure 2 In a preferred embodiment shown, in order to enable the second light spot 102 to move on the substrate 1, the laser assembly 3 includes a laser emitter 31, a beam splitter 32, a first galvanometer 33, a second galvanometer 34, and a focusing lens 35.

[0032] In this context, the x-axis is defined as the direction along which the wire feeding mechanism 2 moves on the substrate 1, and the y-axis is defined as the direction perpendicular to the direction along which the wire feeding mechanism 2 moves. The y-axis is the direction parallel to the surface of the substrate 1.

[0033] The laser emitter 31 emits a main beam, which can be ultraviolet light or infrared light, etc., depending on the requirements.

[0034] Beam splitter 32 divides the main beam into several laser beams 300. Beam splitters can split a beam of light into two or more beams, and they are a key part of most interferometers, usually made of metal films or dielectric films.

[0035] The first galvanometer mirror 33 and the second galvanometer mirror 34 are essentially reflectors. By adjusting their swing angle, the mirrors can change the reflection angle of the laser beam, thus reflecting the laser beam 300 and adjusting its irradiation direction. Specifically, the first galvanometer mirror 33 swings and moves the light spot along the x-axis, while the second galvanometer mirror 34 swings and moves the light spot along the y-axis. Ultimately, the irradiation directions of each first beam 301 simultaneously intersect at the same point on the substrate 1, forming a first light spot 101, or the second light spot 102 moves around the first light spot 101. By quantitatively changing the angle and frequency of the two galvanometer mirrors, the shape, size, and energy density of the coupled light spot are directionally controlled, achieving directional and coordinated coupling control of light spot shape control and energy modulation. It should also be noted that the path of the second spot 102 can be diversified under the action of the galvanometer, such as straight line, arc, etc.; the paths between multiple second spots 102 can also overlap and coincide, and are not independent of each other and do not interfere with each other. Therefore, the coupling forms of the first spot 101 and the second spot 102 and the coupling forms of each second spot 102 can be diversified.

[0036] The focusing lens 35 focuses the laser beam 300 and forms a spot on the substrate 1. The focusing lens 35 can concentrate the energy of the laser beam 300.

[0037] exist Figure 3 In a preferred embodiment shown, theoretically, the second spot 102 moves along the x-axis and y-axis via the first galvanometer 33 and the second galvanometer 34, respectively. However, in reality, the oscillations of the first galvanometer 33 and the second galvanometer 34 are synchronized. Therefore, it can be considered that the movement path of each second spot 102 around the first spot 101 is arc-shaped. At the same time, due to the size limitations of the laser assembly 3, the position of the laser emitter 31 that emits the main beam and the position of each set of galvanometers used to control each laser beam 300 are fixed. This causes interference between laser beams 300 if the direction of each laser beam 300 changes relative to each other. Therefore, theoretically, the movement range of the second spot 102 will not exceed a semi-circular area, that is, the arc angle is not greater than 180°. The starting point of the movement path of the second spot 102 is the center of the arc, and the second spot 102 can move back and forth within this movement path range.

[0038] exist Figure 3In a preferred embodiment shown, the second spot 102 serves as both an auxiliary dynamic coupling laser beam 300 and a shaping laser beam 300. The diameter of the second spot 102 is smaller than that of the first spot 101, so that when multiple second spots 102 surround and move to different positions, they can couple with the larger first spot 101 to form different spot shapes.

[0039] exist Figure 4 In a preferred embodiment shown, the diameter of the second light spot 102 is further larger than the radius of the first light spot 101, but still smaller than the diameter of the first light spot 101. At this point, the area of ​​the second light spot 102 is not significantly smaller than that of the first light spot 101, meaning the second beam 302 is thicker, and the interference between the second beam 302 and the first beam 301 is more pronounced. The advantage of the larger area of ​​the second light spot 102 is that it can cover a larger irradiation area, thereby improving the shaping efficiency of the molten pool 11.

[0040] exist Figure 4 In a preferred embodiment shown, further, since the area of ​​the second spot 102 is larger (but still smaller than the first spot 101), the second beam 302 is also thicker, and the second beam 302 is more likely to interfere with the first beam 301. Therefore, the movement range of the second spot 102 will be reduced accordingly. Specifically, the laser component 3 emits n second beams 302, and the arc of the movement path of each second spot 102 is not less than 360° / n. For example, in this embodiment, three second spots 102 are provided, and the arc of the movement range of each second spot 102 is 120°.

[0041] exist Figure 3 In a preferred embodiment shown, the edge of the second light spot 102 is tangent to the edge of the first light spot 101, and usually has a narrow overlap, so that the second light spot 102 and the first light spot 101 can be effectively coupled.

[0042] exist Figure 3 In a preferred embodiment shown, the moving speed of the second spot 102 is greater than that of the first spot 101, so as to improve the efficiency of spot coupling and laser shaping.

[0043] exist Figure 1 In a preferred embodiment shown, the power of the second beam 302 is not greater than the power of the first beam 301, so as to avoid the second beam 302 having too much power, which would affect the effect of laser shaping.

[0044] like Figure 1 As shown, combined with Figure 3The present invention discloses a laser additive manufacturing method with synergistic spot shape control and energy regulation, employing a laser additive manufacturing apparatus with synergistic spot shape control and energy regulation as described in any of the above embodiments, comprising the following steps.

[0045] Step 1: Activate laser component 3. Laser component 3 emits a first beam 301 and a second beam 302, and forms a first light spot 101 and a second light spot 102 on substrate 1.

[0046] Step two: The wire feeding mechanism 2 is activated to feed wire 21 onto the substrate 1, forming a molten pool 11 on the substrate 1. A detection device 4 is installed above the substrate 1 to detect defects in the molten pool 11. It should be noted that detecting defects in the molten pool 11 using the detection device 4 is a technique already implemented in the field. For example, several monitoring points can be preset along the printing path, and a camera and infrared laser light source can be set next to the molten pool 11. By acquiring images of the molten pool 11 and processing them, the size of the molten pool 11 at each monitoring point can be determined, thereby enabling real-time reflection of defects in the molten pool 11 during the additive manufacturing process.

[0047] Step 3: Based on the defects detected by the detection device 4 in the molten pool 11, each second spot 102 moves around the first spot 101 and shapes the edge of the molten pool 11. The laser assembly 3 and the wire feeding assembly move synchronously along the surface of the substrate 1 and print out the component. Each second spot 102 then continuously shapes the molten pool 11 until the component is printed.

[0048] 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 within the protection scope of the present invention.

Claims

1. A laser additive manufacturing apparatus for synergistic spot shape control and energy regulation, characterized in that, include: substrate(1); The wire feeding mechanism (2) is disposed above the substrate (1) and moves in a direction parallel to the surface of the substrate (1); A laser assembly (3) is disposed above the substrate (1) and emits several laser beams (300). The wire feeding mechanism (2) conveys the wire (21) and defines the wire (21) to be perpendicular to the surface of the substrate (1); Several laser beams (300) are arranged around the filament (21), and the laser beams (300) include a first beam (301) and a second beam (302). The irradiation directions of each of the first beams (301) intersect at the same point on the substrate (1) and form a first spot (101). The first beam (301) melts the wire (21) and forms a molten pool (11) at the location of the first spot (101) on the substrate (1). At least two second light beams (302) respectively irradiate the substrate (1) to form second light spots (102), each second light spot (102) is arranged around the first light spot (101), and the second light spot (102) moves around the first light spot (101) or couples with the first light spot (101); Each of the second light spots (102) moves around the first light spot (101) in an arc shape, with the arc angle not exceeding 180°. The starting point of the movement path of the second light spot (102) is the center of the arc. The edge of the second light spot (102) is tangent to the edge of the first light spot (101). The moving speed of the second light spot (102) is greater than the moving speed of the first light spot (101).

2. The laser additive manufacturing apparatus for synergistic spot shape control and energy regulation according to claim 1, characterized in that: The laser component (3) includes, The laser emitter (31) emits the main beam; Beam splitter (32) splits the main beam into several laser beams (300). The first galvanometer (33) and the second galvanometer (34) reflect the laser beam (300) and adjust the irradiation direction of the laser beam (300); A focusing lens (35) focuses the laser beam (300) and forms a spot on the substrate (1); Wherein, on the substrate (1), the x-axis direction is the direction of movement along the wire feeding mechanism (2), the y-axis direction is the direction perpendicular to the direction of movement along the wire feeding mechanism (2), and the y-axis direction is the parallel direction of the surface of the substrate (1). The first galvanometer (33) swings and moves the light spot along the x-axis, the second galvanometer (34) swings and moves the light spot along the y-axis, and finally the irradiation directions of each of the first beams (301) intersect at the same point on the substrate (1) and form the first light spot (101), or the second light spot (102) moves around the first light spot (101).

3. The laser additive manufacturing apparatus for synergistic spot shape control and energy regulation according to claim 1, characterized in that: The diameter of the second spot (102) is smaller than the diameter of the first spot (101).

4. The laser additive manufacturing apparatus for synergistic spot shape control and energy regulation according to claim 3, characterized in that: The diameter of the second spot (102) is larger than the radius of the first spot (101).

5. The laser additive manufacturing apparatus for synergistic spot shape control and energy regulation according to claim 4, characterized in that: The laser component (3) emits n second beams (302), and the arc of the moving path of each second spot (102) is not less than 360° / n.

6. The laser additive manufacturing apparatus for synergistic spot shape control and energy regulation according to claim 1, characterized in that: The power of the second beam (302) is not greater than the power of the first beam (301).

7. A laser additive manufacturing method with synergistic spot shape control and energy regulation, characterized in that: The laser additive manufacturing apparatus for synergistic spot shape control and energy modulation as described in any one of claims 1 to 6 includes the following steps: Step 1: Activate the laser component (3), which emits a first beam (301) and a second beam (302) and forms a first spot (101) and a second spot (102) on the substrate (1). Step 2: The wire feeding mechanism (2) is started to feed wire (21) onto the substrate (1) and form a molten pool (11) on the substrate (1). A detection device (4) is set above the substrate (1) and the detection device (4) detects defects in the molten pool (11). Step 3: Based on the defects of the molten pool (11) detected by the detection device (4), each of the second light spots (102) moves around the first light spot (101) and shapes the edge of the molten pool (11). The laser component (3) and the wire feeding component move synchronously along the surface of the substrate (1) and print out the component. Each of the second light spots (102) then continuously shapes the molten pool (11) until the component is printed.

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