3D printing laser device with efficient printing and layer-by-layer strengthening functions

Abstract

The invention provides a 3D printing laser device with both efficient printing and layer-by-layer strengthening, and relates to the technical field of laser printing, the 3D printing laser device comprises a laser oscillation unit, a mode switching unit and a laser amplification unit, the laser oscillation unit comprises an optical resonant cavity, an oscillation gain medium, a driving power supply, a semiconductor pumping module and an acousto-optic / electro-optical modulator, the oscillation gain medium, the semiconductor pumping module and the acousto-optic / electro-optical modulator are all arranged in the optical resonant cavity, and the acousto-optic / electro-optical modulator is arranged on a laser light path output by the oscillation gain medium. The laser output in the continuous laser mode and the long-pulse laser mode is suitable for rapidly sintering metal powder and forming a contour, the laser output in the short-pulse laser mode can induce shock wave impact to reinforce a sintered structural part, and the compactness and the structural strength of the part can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of laser printing, and particularly to a 3D printing laser device that combines efficient printing and layer-by-layer strengthening. Background Art

[0002] Traditional laser 3D printing devices usually sinter metal powders with continuous or pulsed lasers during the printing process. However, due to the layer-by-layer stacking characteristics of 3D printing, this method has some problems. For example, tiny pores are likely to form in the sintered parts, and residual stress and structural defects may occur in the components. These factors together lead to a decrease in the density of the components, which in turn has an adverse impact on the overall performance and stability of the product. Summary of the Invention

[0003] The present invention provides a 3D printing laser device that combines efficient printing and layer-by-layer strengthening to solve the problem of poor overall performance and stability of the components printed by existing 3D printing technologies.

[0004] The present invention provides a 3D printing laser device that combines efficient printing and layer-by-layer strengthening, comprising:

[0005] A laser oscillation unit, including an optical resonator, an oscillation gain medium, a driving power supply, a semiconductor pumping module, and an acousto-optic / electro-optic modulator. The oscillation gain medium, the semiconductor pumping module, and the acousto-optic / electro-optic modulator are all arranged in the optical resonator. The acousto-optic / electro-optic modulator is arranged on the laser optical path output by the oscillation gain medium, or between two adjacent oscillation gain media. The semiconductor pumping module is arranged on the outer periphery of the corresponding oscillation gain medium, and the driving power supply is electrically connected to the semiconductor pumping module;

[0006] A mode switching unit, electrically connected to the driving power supply and the acousto-optic / electro-optic modulator. The mode switching unit is used to control the on-off state of the acousto-optic / electro-optic modulator. When the acousto-optic / electro-optic modulator is in the off state, when the mode switching unit outputs a continuous electrical signal or a long pulse electrical signal, the laser device operates in the continuous laser mode or the long pulse laser mode to quickly sinter metal powders. When the acousto-optic / electro-optic modulator is in the on state, when the mode switching unit outputs a continuous electrical signal or a long pulse electrical signal, the loss of the optical resonator is periodically modulated, and the laser device operates in the short pulse laser mode to utilize the shock wave impact effect induced by the laser to strengthen and reinforce the sintered part, reducing the pores that appear during the printing process;

[0007] A laser amplification unit, arranged on the laser optical path output by the optical resonator. The laser amplification unit is used to amplify the laser output by the optical resonator.

[0008] A 3D printing laser device with both high - efficiency printing and layer - by - layer strengthening according to an embodiment of the present invention further includes:

[0009] A laser scanning unit, including a beam diameter regulator, which is arranged on the laser light path output by the laser amplification unit, and the beam diameter regulator is used to adjust the spot size of the laser.

[0010] A 3D printing laser device with both high - efficiency printing and layer - by - layer strengthening according to an embodiment of the present invention, the laser scanning unit further includes:

[0011] A scanning galvanometer, which is arranged on the laser light path output by the beam diameter regulator, and is used to reflect and focus the laser output by the beam diameter regulator onto the required processing and forming platform.

[0012] A 3D printing laser device with both high - efficiency printing and layer - by - layer strengthening according to an embodiment of the present invention, the laser amplification unit includes:

[0013] An amplification gain medium, which is used to amplify the input laser;

[0014] A first combined total reflection mirror, which is arranged on the laser light path output by the optical resonator, and is used to reflect the laser output by the optical resonator into the interior of the amplification gain medium;

[0015] A second combined total reflection mirror, which is arranged on one side of the laser light path output by the optical resonator, and is used to reflect the laser output by the amplification gain medium into the interior of the amplification gain medium.

[0016] A 3D printing laser device with both high - efficiency printing and layer - by - layer strengthening according to an embodiment of the present invention, the laser oscillation unit further includes:

[0017] A dual - channel water cooler, which is connected to the amplification gain medium, the oscillation gain medium, and the semiconductor pump module, and the dual - channel water cooler is used to cool the amplification gain medium, the oscillation gain medium, and the semiconductor pump module.

[0018] A 3D printing laser device with both high - efficiency printing and layer - by - layer strengthening according to an embodiment of the present invention, both the oscillation gain medium and the amplification gain medium are doped with neodymium or ytterbium rare - earth ions. Among them, the middle region of the oscillation gain medium is doped with neodymium or ytterbium rare - earth ions, and the same - length white YAG is bonded to both ends of the oscillation gain medium.

[0019] A 3D printing laser device with both high - efficiency printing and layer - by - layer strengthening according to an embodiment of the present invention, the mode - switching unit includes:

[0020] An acousto-optic / electro-optic driver, electrically connected to the acousto-optic / electro-optic modulator, for controlling the switching state of the acousto-optic / electro-optic modulator;

[0021] A control circuit, electrically connected to the drive power supply and the acousto-optic / electro-optic driver; the control circuit is used to output continuous electrical signals, long pulse electrical signals, and short pulse electrical signals.

[0022] According to an embodiment of the present invention, a 3D printing laser device with both high-efficiency printing and layer-by-layer strengthening. In the continuous laser mode, the output power of the laser device is 100W - 20kW; in the long pulse laser mode, the pulse width of the laser output by the laser device is 100μs - 1000μs, the repetition frequency of the laser is 100Hz - 10kHz, and the peak power of the laser device is 10kW - 200kW; in the short pulse laser mode, the pulse width of the laser output by the laser device is 10ns - 1000ns, the repetition frequency of the laser is 100Hz - 1kHz, and the peak power of the laser device is 100kW - 2000kW.

[0023] According to an embodiment of the present invention, a 3D printing laser device with both high-efficiency printing and layer-by-layer strengthening. The optical resonator includes a total reflection mirror and a coupled output mirror arranged at intervals. The oscillation gain medium, the semiconductor pump module, and the acousto-optic / electro-optic modulator are all arranged between the total reflection mirror and the coupled output mirror, and the coupled output mirror is located between the acousto-optic / electro-optic modulator and the laser amplification unit.

[0024] According to an embodiment of the present invention, a 3D printing laser device with both high-efficiency printing and layer-by-layer strengthening. The surface of the total reflection mirror is coated with a total reflection film with a wavelength of 1.06μm or 1.03μm, and the reflectivity R of the total reflection mirror > 99%; the surface of the coupled output mirror is coated with a reflection film with a wavelength of 1.06μm or 1.03μm, and the reflectivity R of the coupled output mirror ≤ 90%.

[0025] The 3D printing laser device with both high-efficiency printing and layer-by-layer strengthening provided by the embodiment of the present invention has three modes: continuous laser mode, long pulse laser mode, and short pulse laser mode. The lasers output in the continuous laser mode and the long pulse laser mode are suitable for quickly sintering metal powder and forming the contour. The laser output in the short pulse laser mode can induce shock waves to impact and reinforce the sintered components, which is beneficial to improving the density and structural strength of the components. The laser device of the present invention can meet different printing requirements, has a low cost, and is beneficial to the production of high-efficiency and high-quality metal products. Brief Description of the Drawings

[0026] To more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0027] Figure 1 It is one of the structural schematic diagrams of the 3D printing laser device with both high - efficiency printing and layer - by - layer strengthening provided by the embodiments of the present invention to describe the embodiments of the present invention;

[0028] Figure 2 It is the second structural schematic diagram of the 3D printing laser device with both high - efficiency printing and layer - by - layer strengthening provided by the embodiments of the present invention to describe the embodiments of the present invention;

[0029] Figure 3 It is the laser output signal waveform diagram of the 3D printing laser device with both high - efficiency printing and layer - by - layer strengthening provided by the embodiments of the present invention to describe the embodiments of the present invention;

[0030] Figure 4 It is the third structural schematic diagram of the 3D printing laser device with both high - efficiency printing and layer - by - layer strengthening provided by the embodiments of the present invention to describe the embodiments of the present invention.

[0031] Reference numerals:

[0032] 10. Laser oscillation unit; 11. Optical resonator; 12. Oscillation gain medium; 13. Semiconductor pump module; 14. Acousto - optic / electro - optic modulator; 15. Total reflection mirror; 16. Coupling output mirror;

[0033] 20. Mode switching unit; 21. Acousto - optic / electro - optic driver; 22. Control circuit;

[0034] 30. Laser amplification unit; 31. Amplification gain medium; 32. First combined total reflection mirror; 33. Second combined total reflection mirror;

[0035] 40. Laser scanning unit; 41. Beam diameter regulator; 42. Scanning galvanometer;

[0036] 51. Continuous laser; 52. Long - pulse laser; 53. Short - pulse laser. Detailed implementation manners

[0037] The following will further describe in detail the implementation manners of the present invention in combination with the drawings and embodiments. The following embodiments are used to illustrate the present invention, but cannot be used to limit the scope of the present invention.

[0038] In the description of the embodiments of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the embodiments of the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the embodiments of the present invention. In addition, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0039] In the description of the embodiments of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific situations.

[0040] In the embodiments of the present invention, unless otherwise clearly specified and defined, the first feature being "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature can be that the first feature is directly above or obliquely above the second feature, or simply means that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature can be that the first feature is directly below or obliquely below the second feature, or simply means that the first feature has a lower horizontal height than the second feature.

[0041] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the embodiments of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0042] The following is combined with Figures 1-4 Describe the 3D printing laser device with both high-efficiency printing and layer-by-layer strengthening of the embodiments of the present invention.

[0043] As Figure 1 shown, the 3D printing laser device with both high - efficiency printing and layer - by - layer strengthening includes a laser oscillation unit 10, a mode - switching unit 20, and a laser amplification unit 30.

[0044] The laser oscillation unit 10 includes an optical resonator 11, an oscillation gain medium 12, a driving power supply (not shown), a semiconductor pumping module 13, and an acousto - optic / electro - optic modulator 14. The oscillation gain medium 12, the semiconductor pumping module 13, and the acousto - optic / electro - optic modulator 14 are all disposed within the optical resonator 11. The acousto - optic / electro - optic modulator 14 is disposed on the laser optical path output from the oscillation gain medium 12, and the semiconductor pumping module 13 is disposed on the outer periphery of the corresponding oscillation gain medium 12. The driving power supply is electrically connected to the semiconductor pumping module 13.

[0045] The mode - switching unit 20 is electrically connected to the driving power supply and the acousto - optic / electro - optic modulator 14. The mode - switching unit 20 is used to control the on - off state of the acousto - optic / electro - optic modulator 14. When the acousto - optic / electro - optic modulator 14 is in the off state, when the mode - switching unit 20 outputs a continuous electrical signal or a long - pulse electrical signal, the laser device operates in the continuous laser mode or the long - pulse laser mode to quickly sinter metal powder and form a profile. When the acousto - optic / electro - optic modulator 14 is in the on state, when the mode - switching unit 20 outputs a continuous electrical signal or a long - pulse electrical signal, the loss of the optical resonator is periodically modulated, and the laser device operates in the short - pulse laser mode to use the shock wave impact effect induced by the laser to strengthen and reinforce the sintered part, reducing the pores that appear during the printing process.

[0046] The laser amplification unit 30 is disposed on the laser optical path output from the optical resonator 11, and the laser amplification unit 30 is used to amplify the laser output from the optical resonator 11.

[0047] The 3D printing laser device with both high - efficiency printing and layer - by - layer strengthening provided by the embodiment of the present invention has three modes: a continuous laser mode, a long - pulse laser mode, and a short - pulse laser mode. The lasers output in the continuous laser mode and the long - pulse laser mode are suitable for quickly sintering metal powder and forming a profile. The laser output in the short - pulse laser mode can induce shock wave impact to reinforce the sintered component, which is beneficial to improving the density and structural strength of the component. The laser device of the present invention can meet different printing requirements, has a low cost, and is beneficial to the production of high - efficiency and high - quality metal products.

[0048] The 3D printing laser device provided by the embodiment of the present invention, which combines efficient printing and layer-by-layer strengthening, can meet different printing requirements in the same printing process due to the real-time adjustability of the laser operation mode and output parameters. It not only reduces the printing time but also improves the product quality. It has a simple structure, is safe and reliable, and has diverse functions, which not only reduces the equipment procurement cost but also is conducive to realizing the production of high-efficiency and high-quality metal products, and has a wide application prospect.

[0049] In an embodiment of the present invention, the laser oscillation unit 10 includes two oscillation gain media 12. The two oscillation gain media 12 are arranged at intervals on the same straight line. The acousto-optic / electro-optic modulator 14 is arranged between two adjacent oscillation gain media 12 and is on the laser light path output by the previous oscillation gain media 12.

[0050] In an embodiment of the present invention, both the oscillation gain medium 12 and the amplification gain medium 31 are doped with neodymium or ytterbium rare earth ions. Among them, the middle region of the oscillation gain medium 12 is doped with neodymium or ytterbium rare earth ions, and the same length of white YAG (yttrium aluminum garnet) is bonded to both ends of the oscillation gain medium 12 to improve the thermal lens effect and reduce the 1.06μm or 1.03μm laser reabsorption loss.

[0051] In an embodiment of the present invention, the oscillation gain medium 12 is a ytterbium-doped Yb (ytterbium):YAG crystal rod. Optionally, the doped ions of the oscillation gain medium 12 can also be neodymium, and the structure of the oscillation gain medium 12 is a rod structure or a slab structure, and the matrix of the oscillation gain medium 12 is a YAG crystal or ceramic.

[0052] In an embodiment of the present invention, the central wavelength of the semiconductor pump module 13 is 808nm or 940nm, the structure of the semiconductor pump module 13 is an array structure or a surface array structure, and the pumping method is end pumping or side pumping.

[0053] In a preferred embodiment of the present invention, as Figure 1 shown, three groups of semiconductor pump modules 13 with a central wavelength of 940nm are arranged in the optical resonator 11. The three groups of semiconductor pump modules 13 are electrically connected to the drive power supply to optically pump the oscillation gain medium 12, and the pumping method is side pumping. The three groups of semiconductor pump modules 13 surround the outer periphery of the oscillation gain medium 12 for pumping, and the included angle between two adjacent groups of semiconductor pump modules 13 is 120°. Each group of semiconductor pump modules 13 is composed of 40 single bars, and every 10 single bars form a stack array. When the semiconductor pump module 13 performs pulsed pumping, the repetition frequency is 200Hz, and the peak power ≥ 300W / single bar.

[0054] In one embodiment of the present invention, the number of the oscillation gain medium 12 and the semiconductor pumping module 13 in the optical resonator 11 is at least one. When the number of the oscillation gain medium 12 is at least two, every two oscillation gain media 12 are modulated by an acousto-optic / electro-optic modulator 14.

[0055] In one embodiment of the present invention, the 3D printing laser device with both high-efficiency printing and layer-by-layer strengthening further includes a laser scanning unit 40. The laser scanning unit 40 includes a beam diameter regulator 41. The laser scanning unit 40 is arranged on the laser light path output by the laser amplification unit 30. The beam diameter regulator 41 is used to adjust the spot size of the laser. By adjusting the spot size, the laser device can meet different application scenarios and different printing requirements in the same printing process. The adjustable diameter range of the beam diameter regulator 41 is 20 - 300 μm.

[0056] In one embodiment of the present invention, the laser scanning unit 40 further includes a scanning galvanometer 42. The scanning galvanometer 42 is arranged on the laser light path output by the beam diameter regulator 41. The scanning galvanometer 42 is used to reflect and focus the laser output by the beam diameter regulator 41 onto the required processing and forming platform. As Figure 3 shown, the laser reflected and focused by the scanning galvanometer 42 can be continuous laser 51, long pulse laser 52 or short pulse laser 53. The scanning speed of the scanning galvanometer 42 is 0 - 10000 mm / s, and the scanning pitch of the scanning galvanometer 42 is 30 - 80 μm.

[0057] In one embodiment of the present invention, the laser amplification unit 30 includes an amplification gain medium 31, a first combined total reflection mirror 32 and a second combined total reflection mirror 33. The amplification gain medium 31 is used to amplify the input laser. The amplification gain medium 31 is doped with neodymium or ytterbium ions. The structure of the amplification gain medium 31 is a rod structure or a slab structure, and the matrix of the amplification gain medium 31 is a YAG crystal or ceramic. The number of the amplification gain media 31 can be one, two or more. The oscillating laser is amplified by making two round trips in the Yb:YAG crystal rod and then is reflected and focused by the laser scanning unit 40 for output. The laser wavelength is 1.03 μm.

[0058] The first combined total reflection mirror 32 is arranged on the laser light path output by the optical resonator 11 and is used to reflect the laser output by the optical resonator 11 into the interior of the amplification gain medium 31. The first combined total reflection mirror 32 includes two total reflection mirrors, and the two total reflection mirrors form an angle of 45° with the laser light path output by the optical resonator 11. As Figure 1As shown, a total reflection mirror changes the optical path of the laser output from the optical resonator 11 by 90°. At this time, the reflected laser optical path is perpendicular to the laser optical path output from the optical resonator 11; the laser after the first reflection is reflected again by another total reflection mirror for the second reflection, and the laser optical path is changed by 90° again. At this time, the laser optical path after the second reflection is parallel and in the opposite direction to the laser optical path output from the optical resonator 11. The surface of the total reflection mirror is coated with a total reflection film of 1.06 μm or 1.03 μm, and the reflectivity R of the total reflection mirror > 99%.

[0059] The second combined total reflection mirror 33 is arranged on one side of the laser optical path output from the optical resonator 11, and is used to reflect the laser output from the amplification gain medium 31 back into the amplification gain medium 31. The second combined total reflection mirror 33 includes two total reflection mirrors, and both of the two total reflection mirrors form an angle of 45° with the laser optical path output from the optical resonator 11. As Figure 1 shown, a total reflection mirror changes the optical path of the laser output from the amplification gain medium 31 by 90°. At this time, the reflected laser optical path is perpendicular to the laser optical path of the amplification gain medium 31; the laser after the third reflection is reflected by another total reflection mirror again, and the laser optical path is changed by 90° again. At this time, the laser optical path after the fourth reflection is parallel and in the opposite direction to the laser optical path output from the amplification gain medium 31.

[0060] The first combined total reflection mirror 32 and the second combined total reflection mirror 33 form a combined total reflection mirror. There is at least one set of combined total reflection mirrors, and each set of combined total reflection mirrors enables the oscillating laser to be amplified once during a round trip in the amplification gain medium 31. As Figure 1 shown, the first combined total reflection mirror 32 is arranged on the laser optical path output from the optical resonator 11. The first combined total reflection mirror 32 is located at one end of the amplification gain medium 31, and the second combined total reflection mirror 33 is located at the other end of the amplification gain medium 31. The first combined total reflection mirror 32 reflects the laser output from the optical resonator 11 back into the amplification gain medium 31, and the second combined total reflection mirror 33 reflects the laser output from the amplification gain medium 31 back into the amplification gain medium 31, so that the laser makes a round trip in the amplification gain medium 31. In order to achieve multiple amplifications, multiple first combined total reflection mirrors 32 can be arranged at one end of the amplification gain medium 31, and multiple second combined total reflection mirrors 33 can be arranged at the other end of the amplification gain medium 31.

[0061] In an embodiment of the present invention, the laser oscillation unit 10 further includes a dual-channel water cooler (not shown), which is communicated with the amplification gain medium 31, the oscillation gain medium 12, and the semiconductor pumping module 13. The dual-channel water cooler is used to cool the amplification gain medium 31, the oscillation gain medium 12, and the semiconductor pumping module 13. The cooling water temperature of the amplification gain medium 31 and the oscillation gain medium 12 is constantly maintained at T1. When the laser device operates in the continuous laser mode, the cooling water temperature of the semiconductor pumping module 13 is T2. When the laser device operates in the pulsed mode, the cooling water temperature of the semiconductor pumping module 13 is T'2; where T'2 > T2 to compensate for the absorption efficiency loss caused by the blue shift of the central wavelength of the semiconductor pumping module 13 during pulsed operation and ensure the stable high-power output of the laser.

[0062] In an embodiment of the present invention, the mode switching unit 20 includes an acousto-optic / electro-optic driver 21 and a control circuit 22. The acousto-optic / electro-optic driver 21 is electrically connected to the acousto-optic / electro-optic modulator 14 and is used to control the switching state of the acousto-optic / electro-optic modulator 14. The control circuit 22 is electrically connected to the drive power supply and the acousto-optic / electro-optic driver 21; the control circuit 22 is used to output continuous electrical signals, long pulsed electrical signals, and short pulsed electrical signals.

[0063] In an embodiment of the present invention, the laser device operates in the continuous laser mode, the long pulsed laser mode, or the short pulsed laser mode, and the output laser wavelength is 1.06 μm or 1.03 μm. In the continuous laser mode, the output power of the laser device is 100 W - 20 kW. In the long pulsed laser mode, the pulse width of the laser output by the laser device is 100 μs - 1000 μs, the repetition frequency of the laser is 100 Hz - 10 kHz, and the peak power of the laser device is 10 kW - 200 kW. In the short pulsed laser mode, the pulse width of the laser output by the laser device is 10 ns - 1000 ns, the repetition frequency of the laser is 100 Hz - 1 kHz, and the peak power of the laser device is 100 kW - 2000 kW.

[0064] In an embodiment of the present invention, the structure of the optical resonator 11 is a parallel plane cavity or an unstable cavity.

[0065] In a specific embodiment of the present invention, the optical resonator 11 includes a total reflection mirror 15 and a coupling output mirror 16 arranged at intervals. The total reflection mirror 15 and the coupling output mirror 16 are parallel to each other. The oscillation gain medium 12, the semiconductor pumping module 13, and the acousto-optic / electro-optic modulator 14 are all arranged between the total reflection mirror 15 and the coupling output mirror 16. The coupling output mirror 16 is located between the acousto-optic / electro-optic modulator 14 and the laser amplification unit 30, that is, the coupling output mirror 16 is located between the acousto-optic / electro-optic modulator 14 and the second combined total reflection mirror 33.

[0066] In a specific embodiment of the present invention, the surface of the total reflection mirror 15 is coated with a total reflection film with a wavelength of 1.06 μm or 1.03 μm, and the reflectivity R of the total reflection mirror 15 > 99%; the surface of the coupling output mirror 16 is coated with a reflection film with a wavelength of 1.06 μm or 1.03 μm, and the reflectivity R of the coupling output mirror 16 ≤ 90%.

[0067] In a specific embodiment of the present invention, as Figure 2 and Figure 3 shown, the mode switching unit 20 controls the operation mode of the semiconductor pumping module 13 and the switching state of the acousto-optic / electro-optic modulator 14 through the control circuit 22, realizing the output of continuous laser 51, long pulse laser 52, and short pulse laser 53. When the laser mode is continuous operation, the output power can reach 10 kW; when the laser mode is long pulse operation, the peak power can reach 100 kW. The continuous laser 51 and the long pulse laser 52 are suitable for rapid sintering of metal powders. In addition, the relaxation oscillation process of each pulse train in the long pulse operation mode includes multiple ns-level small pulses, which is beneficial to the preliminary reinforcement of metal components. When the laser mode is short pulse operation, the peak power can reach 1000 kW, and the shock wave impact effect is used to further reinforce the sintered metal components.

[0068] In another specific embodiment of the present invention, as Figure 4 shown, in this embodiment, the laser oscillation unit 10 includes two oscillation gain media 12 and two semiconductor pumping modules 13. The two oscillation gain media 12 are arranged at intervals on the same straight line. The acousto-optic / electro-optic modulator 14 is arranged between two adjacent oscillation gain media 12 and is on the laser optical path output by the previous oscillation gain media 12. The two semiconductor pumping modules 13 are arranged on the outer periphery of the two oscillation gain media 12 in a one-to-one correspondence.

[0069] The oscillation gain medium 12 and the amplification gain medium 31 are Nd:YAG slabs doped with neodymium ions. The wavelength of the semiconductor pumping module 13 is 808 nm, and the pumping method is single-sided pumping. When the semiconductor pumping module 13 is long pulse pumping, the repetition frequency is 400 Hz, and the total peak power is greater than or equal to 50 kW. The oscillating laser is reflected and focused by the laser scanning unit 40 after one round-trip amplification in the amplification gain medium 31, and the laser wavelength is 1.06 μm.

[0070] Furthermore, the mode switching unit 20 controls the operating mode of the semiconductor pumping module 13 and the switching state of the acousto-optic / electro-optic modulator 14 through the control circuit 22, so as to achieve the output of continuous, long pulse and short pulse lasers 53. When the laser device operates in the continuous laser mode, the output power can reach 20 kW; when the laser device operates in the long pulse laser mode, the peak power can reach 200 kW. When the laser device operates in the short pulse laser mode, the peak power can reach 2000 kW, and the shock wave impact effect is used to further strengthen the sintered metal component.

[0071] The embodiment of the present invention provides a 3D printing laser device with both high-efficiency printing and layer-by-layer strengthening, which has three operating modes: continuous, long pulse and short pulse lasers. When operating continuously and in long pulses, it realizes the output of high-power and high-peak-power lasers, which is suitable for sintering and initially strengthening metal components; when operating in short pulses, it realizes the output of high-peak-power and short-pulse-width lasers, and uses the shock wave impact effect to further strengthen the metal components and improve the product density and structural strength.

[0072] The 3D printing laser device of the present invention with both high-efficiency printing and layer-by-layer strengthening has three operating modes: continuous, long pulse and short pulse lasers 53, and is suitable for quickly sintering metal powder during 3D printing and using the shock wave impact effect to improve the product density and structural strength.

[0073] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A 3D printing laser device with both high-efficiency printing and layer-by-layer strengthening, characterized in that, Comprising: A laser oscillation unit (10), including an optical resonator (11), an oscillation gain medium (12), a drive power supply, a semiconductor pumping module (13), and an acousto-optic / electro-optic modulator (14). The oscillation gain medium (12), the semiconductor pumping module (13), and the acousto-optic / electro-optic modulator (14) are all disposed within the optical resonator (11). The acousto-optic / electro-optic modulator (14) is disposed on the laser optical path output by the oscillation gain medium (12), or between two adjacent oscillation gain media (12). The semiconductor pumping module (13) is disposed on the outer periphery of the corresponding oscillation gain medium (12). The drive power supply is electrically connected to the semiconductor pumping module (13); A mode switching unit (20), electrically connected to the drive power supply and the acousto-optic / electro-optic modulator (14). The mode switching unit (20) is used to control the on-off state of the acousto-optic / electro-optic modulator (14); When the acousto-optic / electro-optic modulator (14) is in the off state, when the mode switching unit (20) outputs a continuous electrical signal or a long pulse electrical signal, the laser device operates in a continuous laser mode or a long pulse laser mode to rapidly sinter metal powder. When the acousto-optic / electro-optic modulator (14) is in the on state, when the mode switching unit (20) outputs a continuous electrical signal or a long pulse electrical signal, the loss of the optical resonator is periodically modulated, and the laser device operates in a short pulse laser mode to strengthen and reinforce the sintered part by using the shock impact effect induced by the laser, and reduce the pores generated during the printing process; A laser amplification unit (30), disposed on the laser optical path output by the optical resonator (11). The laser amplification unit (30) is used to amplify the laser output by the optical resonator (11).

2. The 3D printing laser device with both high-efficiency printing and layer-by-layer strengthening according to claim 1, wherein Further comprising: A laser scanning unit (40), including a beam diameter regulator (41), disposed on the laser optical path output by the laser amplification unit (30). The beam diameter regulator (41) is used to adjust the spot size of the laser.

3. The 3D printing laser device with both high-efficiency printing and layer-by-layer strengthening according to claim 2, characterized in that, The laser scanning unit (40) further comprises: A scanning galvanometer (42), disposed on the laser optical path output by the beam diameter regulator (41), for reflecting and focusing the laser output by the beam diameter regulator (41) onto the required processing and forming platform.

4. The 3D printing laser device with both high-efficiency printing and layer-by-layer strengthening according to any one of claims 1 to 3, characterized in that, The laser amplification unit (30) comprises: An amplification gain medium (31), used to amplify the input laser; A first combined total reflection mirror (32), disposed on the laser optical path output by the optical resonator (11), for reflecting the laser output by the optical resonator (11) into the interior of the amplification gain medium (31); A second combined total reflection mirror (33), disposed on one side of the laser optical path output by the optical resonator (11), for reflecting the laser output by the amplification gain medium (31) into the interior of the amplification gain medium (31).

5. The 3D printing laser device with both high-efficiency printing and layer-by-layer strengthening according to claim 4, characterized in that, The laser oscillation unit (10) further comprises: A dual-channel water cooler is connected to the amplification gain medium (31), the oscillation gain medium (12), and the semiconductor pump module (13). The dual-channel water cooler is used to cool the amplification gain medium (31), the oscillation gain medium (12), and the semiconductor pump module (13).

6. The 3D printing laser device with both high-efficiency printing and layer-by-layer strengthening according to claim 4, wherein Both the oscillation gain medium (12) and the amplification gain medium (31) are doped with neodymium or ytterbium rare earth ions. Among them, the middle region of the oscillation gain medium (12) is doped with neodymium or ytterbium rare earth ions, and white YAGs of the same length are bonded to both ends of the oscillation gain medium (12).

7. The 3D printing laser device with both high-efficiency printing and layer-by-layer strengthening according to any one of claims 1 to 3, characterized in that, The mode switching unit (20) includes: An acousto-optic / electro-optic driver (21), electrically connected to the acousto-optic / electro-optic modulator (14), and used to control the on / off state of the acousto-optic / electro-optic modulator (14); A control circuit (22), electrically connected to the drive power supply and the acousto-optic / electro-optic driver (21); the control circuit (22) is used to output continuous electrical signals, long pulse electrical signals, and short pulse electrical signals.

8. The 3D printing laser device with both high-efficiency printing and layer-by-layer strengthening according to any one of claims 1 to 3, characterized in that, In the continuous laser mode, the output power of the laser device is 100 W - 20 kW; in the long pulse laser (52) mode, the pulse width of the laser output by the laser device is 100 μs - 1000 μs, the repetition frequency of the laser is 100 Hz - 10 kHz, and the peak power of the laser device is 10 kW - 200 kW; in the short pulse laser mode, the pulse width of the laser output by the laser device is 10 ns - 1000 ns, the repetition frequency of the laser is 100 Hz - 1 kHz, and the peak power of the laser device is 100 kW - 2000 kW.

9. The 3D printing laser device with both high-efficiency printing and layer-by-layer strengthening according to any one of claims 1 to 3, characterized in that, The optical resonator (11) includes a total reflection mirror (15) and a coupling output mirror (16) arranged at intervals. The oscillation gain medium (12), the semiconductor pump module (13), and the acousto-optic / electro-optic modulator (14) are all arranged between the total reflection mirror (15) and the coupling output mirror (16). The coupling output mirror (16) is located between the acousto-optic / electro-optic modulator (14) and the laser amplification unit (30).

10. The 3D printing laser device with both high-efficiency printing and layer-by-layer strengthening according to claim 9, characterized in that, The surface of the total reflection mirror (15) is coated with a total reflection film with a wavelength of 1.06 μm or 1.03 μm, and the reflectivity R of the total reflection mirror (15) > 99%; the surface of the coupling output mirror (16) is coated with a reflection film with a wavelength of 1.06 μm or 1.03 μm, and the reflectivity R of the coupling output mirror (16) ≤ 90%.

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