Laser additive manufacturing device and method cooperating with light spot shape control and energy regulation and control

Abstract

The invention provides a laser additive manufacturing device and method cooperating with light spot shape control and energy regulation and control, and belongs to the field of additive manufacturing. A wire feeding mechanism conveys a wire and limits the wire to be perpendicular to the surface of a substrate; a plurality of laser beams are arranged around the wire material, the laser beams comprise first light beams and second light beams, the irradiation directions of the first light beams intersect at the same point on the substrate at the same time and form a first light spot, and the first light beams fuse the wire material and form a molten pool at the position of the first light spot on the substrate; and the second light beams irradiate the substrate to form second light spots, the second light spots are arranged around the first light spot, the second light spots move around the first light spot or are coupled with the first light spot, and the shapes and energy distribution of the light spots are cooperatively regulated and controlled. Coaxial laser cooperative scanning is adopted, dynamic adjustment and cooperative coupling of the light spot shape and energy distribution in the additive manufacturing process are achieved, the shape, size, depth and other characteristics of a molten pool are accurately controlled, and the high-efficiency and high-precision additive manufacturing requirements of complex components are met.

Description

Technical Field

[0001] The present invention relates to the field of additive manufacturing technology, and in particular to a laser additive manufacturing device and method for coordinated spot shape control and energy regulation. Background Art

[0002] As components in aerospace and other industries develop towards large-scale and integrated development, traditional manufacturing technologies have disadvantages such as long development cycles, high costs, and low material utilization. Laser additive manufacturing technology provides a new solution with obvious technical and economic advantages such as digitalization, precision, design-material-manufacturing integration, short cycles, and rapid iterations. However, current laser additive manufacturing technologies generally face the shortcoming of being unable to balance forming efficiency and precision. Under the premise of pursuing high manufacturing efficiency, it is easy to lead to a decrease in forming accuracy, increase machining difficulty, and cause material waste, which is contrary to its technical concept of fast and short-process manufacturing.

[0003] Proposing corresponding melt pool shaping strategies based on the structural characteristics of each part of the component is a key way to solve the mismatch between forming accuracy and efficiency in laser additive manufacturing. At present, melt pool shaping technology has been widely used in laser additive manufacturing. However, due to the large differences in structural wall thickness and geometric shapes of large and complex components, in their additive manufacturing process, traditional melt pool shaping technology still has technical bottlenecks such as difficulty in coordinating spot shape control and energy regulation, and cannot meet the technical requirements of balancing forming accuracy and efficiency in the additive manufacturing process 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 coordinated spot shape control and energy regulation, which is used to solve the problem that traditional molten pool shaping technology is difficult to break through the technical bottleneck of coordinated regulation of spot shape and energy distribution in the additive manufacturing process.

[0005] The technical solution of the present invention is implemented as follows: the present invention provides a laser additive manufacturing device with coordinated spot shape control and energy regulation, including a substrate; a wire feeding mechanism, which is arranged above the substrate and moves in a direction parallel to the surface of the substrate; a laser assembly, which is arranged above the substrate and emits a plurality of laser beams; wherein the wire feeding mechanism conveys the wire and limits the wire to be perpendicular to the surface of the substrate; a plurality of laser beams are arranged around the wire, 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 are respectively irradiated on the substrate to form second spots, each second spot is arranged around the first spot, and the second spot moves around the first spot or is coupled with the first spot.

[0006] On the basis of the above technical scheme, preferably, the laser assembly includes a laser emitter, which emits a main light beam; a beam splitter, which divides the main light beam into several laser beams; a first galvanometer and a second galvanometer, which reflect the laser beam and adjust the irradiation direction of the laser beam; a focusing mirror, which focuses the laser beam and forms a light spot on the substrate; wherein, on the substrate, the x-axis direction is along the moving direction of the wire feeding mechanism, the y-axis direction is perpendicular to the moving direction of the wire feeding mechanism, and the y-axis direction is parallel to the surface of the substrate; the first galvanometer swings and moves the light spot along the x-axis direction, the second galvanometer swings and moves the light spot along the y-axis direction, and finally the irradiation directions of the first light beams cross at the same point on the substrate at the same time to form a first light spot, or the second light spot moves around the first light spot.

[0007] More preferably, the moving path of each second light spot around the first light spot is in an arc shape, the arc angle of the arc is not greater than 180°, and the starting point of the moving path of the second light spot is the center of the arc.

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

[0009] More preferably, the diameter of the second light spot is greater than the radius of the first light spot.

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

[0011] On the basis of the above technical solution, preferably, the edge of the second light spot is tangent to the edge of the first light spot.

[0012] On the basis of the above technical solution, preferably, the moving speed of the second light spot is greater than the moving speed of the first light spot.

[0013] On the basis of the above technical solution, preferably, the power of the second light beam is not greater than the power of the first light beam.

[0014] On the other hand, the present invention also provides a laser additive manufacturing method with coordinated spot shape control and energy regulation, which uses the above-mentioned laser additive manufacturing device with coordinated spot shape control and energy regulation, including the following steps: step one, start the laser component, the laser component emits a first light beam and a second light beam, and forms a first light spot and a second light spot on the substrate; step two, start the wire feeding mechanism to transport wire to the substrate and form a molten pool on the substrate, and a detection device is arranged above the substrate, and the detection device detects defects in the molten pool; step three, according to the defects of the molten pool detected by the detection device, each second light spot moves around the first light spot and shapes the edge of the molten pool, the laser component and the wire feeding component move synchronously along the surface of the substrate and print out the component, and each second light spot continues to shape the molten pool until the component is printed.

[0015] The laser additive manufacturing device and method of the present invention that coordinates spot shape control and energy regulation has the following beneficial effects compared with the prior art:

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

[0017] (2) The present invention controls the relative movement of the second light spot relative to the first light spot in the x-axis and y-axis directions by quantitatively changing the swing angle and frequency of the two galvanometer mirrors, thereby achieving directional control of the light spot shape, size and energy density, that is, achieving directional coordinated coupling control of light spot shape control and energy modulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 is a three-dimensional diagram of the additive manufacturing device of the present invention;

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

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

[0022] Figure 4 It 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 light spot; 102. second light spot; 2. wire feeding mechanism; 3. laser assembly; 31. laser emitter; 32. beam splitter; 33. first galvanometer; 34. second galvanometer; 35. focusing mirror; 300. laser beam; 301. first light beam; 302. second light beam; 4. detection device. DETAILED DESCRIPTION

[0024] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] like Figure 1 As shown, combined Figure 3 The present invention discloses a laser additive manufacturing device that coordinates spot shape control and energy regulation, including a substrate 1, a wire feeding mechanism 2 and a laser component 3.

[0026] The components are formed on the substrate 1, and the surface of the substrate 1 is kept horizontal.

[0027] The wire feeding mechanism 2 is arranged above the substrate 1 and moves in a direction parallel to the surface of the substrate 1. The wire feeding mechanism 2 transports the wire 21 and limits the wire 21 to be perpendicular to the surface of the substrate 1. It should be noted that the wire feeding mechanism 2 can also be a powder feeding mechanism or a silk-powder composite feeding mechanism, and the feeding material can be a wire 21, a powder material or a silk-powder composite material. The laser assembly 3 in the present application is mainly designed in conjunction with the wire feeding mechanism 2 so that the laser beam 300 is coaxially arranged around the wire 21. Assuming that the feeding mechanism is a powder feeding mechanism, the laser beam 300 for printing, that is, the first beam 301, can be set to be vertically emitted to the substrate 1; and the laser beam 300 for shaping, that is, the second beam 302, is coaxially arranged around the first beam 301.

[0028] The laser assembly 3 is disposed above the substrate 1 and emits a plurality of laser beams 300 . The plurality of laser beams 300 are arranged around the wire 21 .

[0029] The laser beam 300 includes a first light beam 301 and a second light beam 302. The irradiation direction of each first light beam 301 crosses the same point on the substrate 1 at the same time and forms a first light spot 101. The first light beam 301 melts the wire 21 and forms a molten pool 11 at the location of the first light spot 101 on the substrate 1; at least two second light beams 302 are irradiated on the substrate 1 to form second light spots 102, and each second light spot 102 is arranged around the first light spot 101. The second light spot 102 moves around the first light spot 101 and irradiates the edge of the molten pool 11 for shaping, or couples with the first laser 101 to achieve the purpose of coordinated regulation of the shape and energy distribution of the light spot. By adopting coaxial laser collaborative scanning, the dynamic adjustment of the light spot shape and the coordinated coupling of the energy distribution in the additive manufacturing process are realized, and the molten pool characteristics such as shape, size and depth are accurately controlled to meet the high-efficiency and high-precision additive manufacturing requirements of complex components.

[0030] In this embodiment, multiple first light beams 301 are coaxially arranged around the wire 21, and each first light beam 301 crosses the same point so that multiple light spots overlap to form a first light spot 101, realizing the cross-superposition of light spots. However, since the emission direction of each first light beam 301 is fixed, the first light spot 101 formed by coupling has a fixed light spot shape, size and energy distribution, which is difficult to meet the requirements for light spot characteristics when forming a molten pool 11 with different shapes, sizes and depths, and thus cannot meet the requirements for forming efficiency, precision and performance 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 light beam 101 for printing the component, but also the second light beam 102. The second light beam 102 has two functions here: first, the emission direction of the second light beam 102 is variable so that the second light spot 102 formed by it can be moved on the substrate 1, thereby changing the coupling condition between the second light spot 102 and the first light spot 101; for example, the first light spot 101 is generally circular, and assuming that there are three second light spots 102 evenly distributed around the first light spot 101, the shape of the coupled light spot formed by the second light spot 102 and the first light spot 101 is similar to a triangle, and the arrangement of the three second light spots 102 can be adjusted relative to the printing direction, thereby adapting to more forming requirements of the molten pool 11. Secondly, the second light beam 302 also serves as a shaping laser. When the molten pool 11 is formed and its edge gradually spreads outward and solidifies, the edge of the molten pool 11 may produce defects in different situations due to factors such as the printing speed, the properties of the wire 21, the size of the printing spot, and the energy intensity. The defects at different positions on the edge of the molten pool 11 may also be different. When the second light spot 102 formed by the second light beam 302 moves around the first light spot 101, it can be purposefully moved to the defective position at the edge of the molten pool 11 for shaping. For example, if there is a thicker protrusion at the edge of the molten pool 11, the second light spot 102 moves to the protrusion to melt it, so that it is gradually flattened to eliminate the defects of the molten pool 11.

[0031] exist Figure 2 In a preferred embodiment shown, in order to achieve the mobility of the second light spot 102 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 mirror 35 .

[0032] Among them, on the substrate 1, the moving direction of the wire feeding mechanism 2 is the x-axis direction, the vertical direction along the moving direction of the wire feeding mechanism 2 is the y-axis direction, and the y-axis direction is a direction parallel to the surface of the substrate 1.

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

[0034] The beam splitter 32 splits the main beam into several laser beams 300. The beam splitter can split a beam of light into two or more beams, and is a key part of most interferometers, and is usually made of a metal film or a dielectric film.

[0035] The first galvanometer 33 and the second galvanometer 34 are essentially reflectors. The galvanometers can change the reflection angle of the light beam by adjusting their swing angles, so that the first galvanometer 33 and the second galvanometer 34 reflect the laser beam 300 and adjust the irradiation direction of the laser beam 300. Specifically, the first galvanometer 33 swings and moves the light spot along the x-axis direction, and the second galvanometer 34 swings and moves the light spot along the y-axis direction, and finally makes the irradiation directions of each first light beam 301 cross at the same point on the substrate 1 at the same time and form the first light spot 101, or makes the second light spot 102 move around the first light spot 101. Directional control of the shape, size and energy density of the coupled light spot is achieved by quantitatively changing the angle and frequency of the two galvanometers, that is, directional coordinated coupling control of light spot shape control and energy modulation is achieved. It should also be noted that, under the action of the galvanometer, the paths of the second light spots 102 can be diversified, such as straight lines, arcs, etc.; the paths between multiple second light spots 102 can also overlap, and are not independent of each other and do not interfere with each other, so the coupling forms of the first light spot 101 and the second light spot 102 and the coupling forms of each second light spot 102 can be diversified.

[0036] The focusing mirror 35 focuses the laser beam 300 and forms a light spot on the substrate 1. The focusing mirror 35 can make the energy of the laser beam 300 more concentrated.

[0037] exist Figure 3 In a preferred embodiment shown, theoretically, the second light spot 102 is moved on the x-axis and the y-axis respectively by the first galvanometer 33 and the second galvanometer 34, but in fact, the swing of the first galvanometer 33 and the second galvanometer 34 is synchronous, so it can be regarded that the movement path of each second light spot 102 around the first light spot 101 is in the shape of an arc; at the same time, due to the equipment volume limitation of the laser assembly 3, the position of the laser emitter 31 that emits the main light beam and the position of each group of galvanometers used to control each laser beam 300 are fixed, which causes interference between the laser beams 300 if the emission direction of each laser beam 300 changes relatively, so theoretically, the movement range of the second light spot 102 will not exceed a semicircular area, that is, the arc of the arc is not greater than 180°, and the starting point of the movement path of the second light spot 102 is the center of the arc, and the second light spot 102 can move back and forth within the range of the movement path.

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

[0039] exist Figure 4 In a preferred embodiment shown, further, the diameter of the second light spot 102 is larger than the radius of the first light spot 101, but at the same time still smaller than the diameter of the first light spot 101. At this time, the area of ​​the second light spot 102 is not much smaller than that of the first light spot 101, that is, the second light beam 302 is thicker, and the second light beam 302 and the first light beam 301 interfere with each other more significantly. The advantage of the larger area of ​​the second light spot 102 is that it can cover more irradiation areas, 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 light spot 102 is larger (but still smaller than the first light spot 101), the second light beam 302 is also thicker, and the second light beam 302 is more likely to interfere with the first light beam 301, and thus the moving range of the second light spot 102 will be correspondingly reduced. Specifically, the laser component 3 emits n second light beams 302, and the arc of the moving path of each second light spot 102 is not less than 360° / n. For example, three second light spots 102 are provided in this embodiment, and the arc of the moving range of each second light 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 overlapping portion, 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 light spot 102 is greater than the moving speed of the first light spot 101, so as to improve the efficiency of light spot coupling and the efficiency of laser shaping.

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

[0044] like Figure 1 As shown, combined Figure 3The present invention provides a laser additive manufacturing method that coordinates spot shape control and energy regulation, using a laser additive manufacturing device that coordinates spot shape control and energy regulation of any of the above embodiments, and includes the following steps.

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

[0046] Step 2: Start the wire feeding mechanism 2 to feed the wire 21 onto the substrate 1 and form a molten pool 11 on the substrate 1. A detection device 4 is provided above the substrate 1 to detect defects of the molten pool 11. It should be noted that detecting defects of the molten pool 11 by the detection device 4 is a technical means that has been realized in this field. For example, a number of monitoring points can be preset along the printed travel trajectory, and a camera and an infrared laser light source can be set next to the molten pool 11. By collecting and processing the image of the molten pool 11, the size of the molten pool 11 at each monitoring point can be obtained, so that the defects of the molten pool 11 can be reflected in real time during the additive manufacturing process.

[0047] Step three, according to the defects of the molten pool 11 detected by the detection device 4, each second light spot 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, and each second light spot 102 continues to shape 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 in the protection scope of the present invention.

Claims

1. A laser additive manufacturing device that coordinates spot shape control and energy regulation, characterized in that: include: base(1); A wire feeding mechanism (2) is arranged above the substrate (1) and moves in a direction parallel to the surface of the substrate (1); A laser assembly (3) is arranged above the substrate (1) and emits a plurality of laser beams (300); The wire feeding mechanism (2) feeds the wire (21) and limits the wire (21) to be perpendicular to the surface of the substrate (1); A plurality of laser beams (300) are arranged around the wire (21), and the laser beams (300) include a first beam (301) and a second beam (302). The irradiation directions of the first light beams (301) simultaneously intersect at the same point on the substrate (1) and form a first light spot (101); the first light beams (301) melt the wire (21) and form a molten pool (11) at the location of the first light spot (101) on the substrate (1); At least two of the second light beams (302) are respectively irradiated onto the substrate (1) to form second light spots (102), each of the second light spots (102) is arranged around the first light spot (101), and the second light spots (102) move around the first light spot (101) or are coupled with the first light spot (101).

2. The laser additive manufacturing device with coordinated spot shape control and energy regulation according to claim 1, characterized in that: The laser assembly (3) comprises: A laser emitter (31) emits a main beam; A beam splitter (32) for splitting the main beam into a plurality of laser beams (300); A first galvanometer (33) and a second galvanometer (34) are used to reflect the laser beam (300) and adjust the irradiation direction of the laser beam (300); A focusing lens (35) for focusing the laser beam (300) and forming a light spot on the substrate (1); Wherein, on the substrate (1), the moving direction of the wire feeding mechanism (2) is the x-axis direction, the vertical direction along the moving direction of the wire feeding mechanism (2) is the y-axis direction, and the y-axis direction is the direction parallel to the surface of the substrate (1); The first galvanometer (33) swings to move the light spot along the x-axis direction, and the second galvanometer (34) swings to move the light spot along the y-axis direction, and finally the irradiation directions of the first light beams (301) simultaneously cross at the same point on the substrate (1) to form a first light spot (101), or the second light spot (102) moves around the first light spot (101).

3. The laser additive manufacturing device with coordinated spot shape control and energy regulation according to claim 2, characterized in that: The moving path of each of the second light spots (102) around the first light spot (101) is in the shape of an arc, the arc angle of the arc is not greater than 180°, and the starting point of the moving path of the second light spot (102) is the exact center of the arc.

4. The laser additive manufacturing device with coordinated spot shape control and energy regulation according to claim 3 is characterized in that: The diameter of the second light spot (102) is smaller than the diameter of the first light spot (101).

5. The laser additive manufacturing device with coordinated spot shape control and energy regulation according to claim 4, characterized in that: The diameter of the second light spot (102) is greater than the radius of the first light spot (101).

6. The laser additive manufacturing device with coordinated spot shape control and energy regulation according to claim 5, characterized in that: The laser assembly (3) emits n second light beams (302), and the arc of the moving path of each second light spot (102) is not less than 360° / n.

7. The laser additive manufacturing device with coordinated spot shape control and energy regulation according to claim 1, characterized in that: The edge of the second light spot (102) is tangent to the edge of the first light spot (101).

8. The laser additive manufacturing device with coordinated spot shape control and energy regulation according to claim 1, characterized in that: The moving speed of the second light spot (102) is greater than the moving speed of the first light spot (101).

9. The laser additive manufacturing device with coordinated spot shape control and energy regulation according to claim 1, characterized in that: The power of the second light beam (302) is not greater than the power of the first light beam (301).

10. A laser additive manufacturing method with coordinated spot shape control and energy regulation, characterized in that: A laser additive manufacturing device for coordinated spot shape control and energy regulation according to any one of claims 1 to 9 comprises the following steps: Step 1: Start the laser component (3), the laser component (3) emits a first light beam (301) and a second light beam (302), and forms a first light spot (101) and a second light spot (102) on the substrate (1); Step 2: starting the wire feeding mechanism (2) to feed the wire material (21) onto the substrate (1) and forming a molten pool (11) on the substrate (1); a detection device (4) is arranged above the substrate (1); and the detection device (4) detects defects in the molten pool (11); Step three, 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, and each of the second light spots (102) continues to shape the molten pool (11) until the component is printed.

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