Multi-wavelength beam synergistic additive forming apparatus

Abstract

The utility model discloses a kind of multi-wavelength light beam synergic additive forming equipment, the continuous laser generation device of composite laser emission device is continuously emitted wavelength 1064nm red light laser beam towards the powder field on the working plane of forming chamber and carries out powder melting to form molten pool, the pulse laser generation device of composite laser emission device is emitted wavelength 400-532nm green light or blue light pulse laser beam towards the molten pool under semi-melting state, dendrite in molten pool is in situ broken to form equiaxed crystal, the femtosecond laser generation device of composite laser emission device emits wavelength 780-2526nm femtosecond laser beam to the profile of the current layer of forming piece and carries out cutting modification, control system controls continuous laser generation device, pulse laser generation device and femtosecond laser generation device start-stop work, the utility model makes SLM forming piece have excellent comprehensive mechanical property, fatigue resistance and higher dimensional accuracy.

Description

Technical Field

[0001] This utility model relates to the field of additive manufacturing technology, and in particular to a multi-wavelength beam collaborative additive molding equipment. Background Technology

[0002] SLM (Surface Mount Laser) printing is a major technique in additive manufacturing of metal materials. This technology uses a laser as its energy source, scanning layer by layer through a metal powder bed according to a pre-planned path in a 3D CAD slicing model. The scanned metal powder melts and solidifies to achieve a metallurgical bond, ultimately producing the metal part designed in the model.

[0003] SLM technology overcomes the challenges of manufacturing metal parts with complex shapes using traditional techniques. SLM-formed parts have a density comparable to castings and forgings, while their hardness and strength are higher than castings and comparable to forgings.

[0004] During the SLM process, the Gaussian beam of infrared light has high penetrability. During the rapid melting of powder, problems such as spatter and keyholes are easily generated in the molten pool. The large temperature gradient between layers leads to the formation of coarse dendrites with epitaxial growth. The longitudinal section of the SLM-formed part has a strong preferred orientation, mainly small-angle grain boundaries, indicating that there is significant texture and a large number of large columnar crystals growing along the printing (temperature gradient) direction. There is also often obvious unmelted powder in the SLM-formed part. These problems result in lower overall mechanical properties (mainly toughness and elongation) and lower fatigue performance of the SLM-formed part, resulting in a shorter service life than castings and forgings. Utility Model Content

[0005] To overcome the above-mentioned defects, this utility model provides a multi-wavelength beam collaborative additive manufacturing equipment. Using this multi-wavelength beam collaborative additive manufacturing equipment can effectively solve the problems of keyhole and spatter in the melt pool during the SLM process, low elongation of SLM formed parts and easy fatigue, effectively improve the overall performance of SLM printed parts and extend the service life of SLM printed parts.

[0006] The technical solution adopted by this utility model to solve its technical problem is as follows: a multi-wavelength beam collaborative additive manufacturing equipment, including a forming chamber, a composite laser emitting device, and a control system. The composite laser emitting device includes a continuous laser generator, a pulsed laser generator, and a femtosecond laser generator. The continuous laser generator can emit a continuous red laser beam toward the powder field on the working plane of the forming chamber to melt the powder and form a molten pool. The pulsed laser generator can emit a green or blue pulsed laser beam toward the molten pool of the powder field to realize the post-processing of the molten pool. The femtosecond laser generator can emit a femtosecond laser beam to cut and shape the contour of the formed part. The control system can control the start and stop of the continuous laser generator, the pulsed laser generator, and the femtosecond laser generator.

[0007] As a further improvement of this utility model, the continuous laser generating device includes a red laser, a first collimation module, a first scanning galvanometer, and a first field mirror. The red laser can emit a red laser beam, the first collimation module can collimate the red laser beam, and the first scanning galvanometer and the first field mirror can focus the collimated red laser beam on the forming position on the powder field surface for powder melting and forming.

[0008] The pulsed laser generating device includes a green or blue laser, a second collimation module, a second scanning galvanometer, and a second field mirror. The green or blue laser can emit green or blue pulsed laser beams, the second collimation module can collimate the green or blue pulsed laser beams, and the second scanning galvanometer and the second field mirror can focus the collimated green or blue pulsed laser beams onto the molten pool position on the powder field surface to break up dendrites within the molten pool.

[0009] The femtosecond laser generator includes an ultrashort pulse laser, a third collimation module, a third scanning galvanometer, and a third field mirror. The ultrashort pulse laser emits a femtosecond laser beam (ultrashort pulse laser beam), the third collimation module collimates the femtosecond laser beam (ultrashort pulse laser beam), and the third scanning galvanometer and third field mirror focus the collimated femtosecond laser beam (ultrashort pulse laser beam) onto the inner and outer contours of the current layer of the formed part. The femtosecond laser beam uses a non-thermal ablation mechanism to perform in-situ cutting and precise shaping of the inner and outer contours of the current layer of the formed part.

[0010] As a further improvement of this utility model, the continuous laser generating device also includes a dynamic beam shaping module, which can shape a Gaussian beam into a uniform ring beam, a flat-top beam, or a Bessel beam by using diffractive optical elements or a double-cone prism.

[0011] As a further improvement of this utility model, the wavelength of the red laser beam is 1064nm, the wavelength of the green or blue laser beam is 400-532nm, the femtosecond laser beam is an ultrashort pulse laser beam with a wavelength of 780-2526nm (preferably 1064nm) and a pulse width of <50f, and the continuous laser generator and the pulse laser generator are arranged horizontally in a flat manner on the top of the forming chamber, or in a staggered stepped arrangement with high and low positions.

[0012] As a further improvement of this utility model, the upper surface of the bottom plate of the forming chamber is a working plane. The bottom plate of the forming chamber is provided with a forming cylinder mounting port, and also provides a forming cylinder and a powder spreading device. The upper end of the forming cylinder body can be sealed and installed in the forming cylinder mounting port. The upper end face of the forming cylinder body is horizontally aligned with the working plane. A substrate heating system is provided on the piston of the forming cylinder. The forming substrate is placed on the substrate heating system in a circumferential direction. The substrate heating system can intelligently heat the forming substrate based on temperature control technology to maintain its temperature within a set temperature range. The powder spreading device can spread powder in the forming cylinder and ensure that the powder is horizontally aligned with the working plane to form a powder field. The control system controls the piston lifting and lowering movement of the forming cylinder, the intermittent powder spreading by the powder spreading device, and the constant temperature heating of the forming substrate by the substrate heating system.

[0013] As a further improvement of this utility model, the forming cylinder includes a hot cylinder, a cold cylinder, and a heat insulation ring. The hot cylinder, the heat insulation ring made of heat insulation material, and the cold cylinder are fixedly connected from top to bottom to form an integral structure. The piston of the forming cylinder is always located in the cold cylinder. The substrate heating system includes a self-stacked heating base plate, an upper cooling base plate, an upper heat insulation base plate, a connecting block, a lower heat insulation base plate, and a lower cooling base plate. Several heating rods are evenly distributed in an array within the heating base plate. Each heating rod can simultaneously heat the forming substrate. The upper cooling base plate and the lower cooling base plate... The base plate is equipped with a cooling water circulation channel, which can rapidly cool the upper and lower cooling base plates. The upper heat-insulating base plate, made of heat-insulating material, can insulate the upper cooling base plate and the upper end of the connecting block. The lower heat-insulating base plate, also made of heat-insulating material, can insulate the lower end of the connecting block and the lower cooling base plate. Powder sealing rings and gas sealing rings are respectively installed on the outer circumference of the upper cooling base plate and the piston. The powder sealing ring can prevent powder on the forming substrate from leaking downwards, and the gas sealing ring can prevent inert gas in the forming chamber from leaking outwards along the forming cylinder.

[0014] As a further improvement of this utility model, the heating base plate is also provided with a temperature sensor. The temperature sensor can sense the temperature of the forming substrate in real time and transmit its sensing signal to the control system. The control system controls the heating rod to start or stop or adjusts the heating efficiency of the heating rod.

[0015] As a further improvement of this utility model, the forming chamber is provided with an air inlet and an air outlet on its two opposite side walls. Inert gas can enter the forming chamber through the air inlet and carry away the dust in the forming chamber through the air outlet. The bottom plate of the forming chamber is provided with two recycling cylinder mounting ports, which are located on both sides of the forming cylinder mounting port along the direction of movement of the powder spreading device. Recycling cylinders can be sealed in the two recycling cylinder mounting ports. During the reciprocating motion of the powder spreading device, excess powder (40) can be scraped into the recycling cylinder for storage. The piston of the recycling cylinder can move up and down to adjust the powder holding space.

[0016] A multi-wavelength beam collaborative additive manufacturing method includes the following steps:

[0017] Step 1: The powder field in the forming chamber is melted to form a molten pool by using a continuous red laser beam with a wavelength of 1064nm.

[0018] Step 2: Use a green or blue pulsed laser beam with a wavelength of 400-532nm to break up dendrites in the semi-molten pool in situ to form equiaxed crystals, thereby increasing the proportion of equiaxed crystals in the molten pool.

[0019] Step 3: Use a femtosecond laser beam with a wavelength of 780-2526nm to cut and shape the contour of the current layer of the forming part.

[0020] As a further improvement of this utility model, when the powder field is melted and formed by the red continuous laser beam and the green or blue pulsed laser beam, the forming substrate that is in direct contact with the forming part is heated by the substrate heating system, so that the forming substrate is maintained in a constant temperature range of >350°C.

[0021] The beneficial effects of this invention are as follows: This invention uses a red laser beam to melt and print powder in a powder field, and uses a green or blue laser beam to break dendrites in situ while the molten pool is semi-molten, thereby increasing the proportion of equiaxed crystals in the molten pool and effectively reducing cracks and pores in the SLM formed parts. In the SLM process, this invention uses a femtosecond laser to cut the contour line of the SLM formed parts in the current layer in situ, improving the forming accuracy of the SLM formed parts. This invention also uses a dynamic beam shaping module to shape the red laser beam into a ring beam, Bessel beam, or flat-top beam, effectively reducing spatter and keyholes in the molten pool, allowing the red laser beam to be processed and formed at high power. This invention gives the SLM formed parts excellent comprehensive mechanical properties (mainly high toughness and elongation), high fatigue resistance, and long service life. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the metal powder melting and forming process in the prior art;

[0023] Figure 2 This is a diagram of the crystal growth state within the molten pool in the existing technology;

[0024] Figure 3 This is a front view of the device structure principle of this utility model;

[0025] Figure 4 This is a top view of the device structure principle of this utility model;

[0026] Figure 5 This is a diagram showing the state of dendrites breaking up in a molten pool using the green laser beam of this invention.

[0027] Figure 6 This is a schematic diagram illustrating the structural principle of the forming cylinder of this utility model;

[0028] Figure 7 This is a schematic diagram showing the distribution of heating rods on the heating base plate. Detailed Implementation

[0029] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0030] Example: A multi-wavelength beam collaborative additive manufacturing equipment includes a forming chamber 1, a composite laser emitting device, and a control system. The composite laser emitting device includes a continuous laser generator 42, a pulsed laser generator 43, and a femtosecond laser generator 44. The continuous laser generator 42 can emit a continuous red laser beam 2 towards the powder field on the working plane of the forming chamber 1 to melt the powder 40 and form a molten pool. The pulsed laser generator 43 can emit a green or blue pulsed laser beam 3 towards the molten pool of the powder field to achieve post-processing of the molten pool. The femtosecond laser generator 44 can emit a femtosecond laser beam 4 to cut and shape the contour of the formed part 5. The control system can control the start and stop of the continuous laser generator 42, the pulsed laser generator 43, and the femtosecond laser generator 44.

[0031] During the printing process, a red laser beam 2 is emitted from a continuous laser generator 42 toward the powder field to melt the powder 40 and form a molten pool, serving as the main melting and forming laser. Simultaneously, a green or blue pulsed laser beam 3 is emitted from a pulsed laser generator 43 toward the molten pool to stir the solidifying molten pool, breaking the coarse dendrites in the molten pool into fine equiaxed crystals, reducing cracks and pores in the formed part 5. The green or blue pulsed laser beam also enables micro-forging of the molten pool at high temperatures, which can improve the elongation and fatigue resistance of the formed part 5. The formed part 5 is melted and formed by the synergistic action of the red laser beam 2 and the green or blue pulsed laser beam. After forming, the femtosecond laser generator 44 can emit a femtosecond laser beam 4 to cut the contour of the current layer of the formed part 5, achieving in-situ precision shaping.

[0032] The above-mentioned printing equipment effectively solved the problems of keyholes and spatter in the SLM molded part 5, greatly improved the elongation and fatigue strength of the SLM molded part 5, fully enhanced the comprehensive performance of the molded part 5, and ensured the dimensional accuracy and aesthetic appearance of the molded part 5.

[0033] The continuous laser generating device 42 includes a red laser 6, a first collimation module 7, a first scanning galvanometer 8, and a first field mirror 9. The red laser 6 can emit a red laser beam 2, the first collimation module 7 can collimate the red laser beam 2, and the first scanning galvanometer 8 and the first field mirror 9 can focus the collimated red laser beam 2 on the forming position on the powder field surface to melt and form the powder 40.

[0034] The pulsed laser generating device 43 includes a green or blue laser 10, a second collimation module 11, a second scanning galvanometer 12, and a second field mirror 13. The green or blue laser 10 can emit a green or blue pulsed laser beam 3. The second collimation module 11 can collimate the green or blue pulsed laser beam. The second scanning galvanometer 12 and the second field mirror 13 can focus the collimated green or blue pulsed laser beam onto the molten pool position on the powder field surface to break up dendrites in the molten pool.

[0035] The femtosecond laser generator 44 includes an ultrashort pulse laser 14, a third collimation module 15, a third scanning galvanometer 16, and a third field mirror 17. The ultrashort pulse laser 14 can emit a femtosecond laser beam 4 (ultrashort pulse laser beam). The third collimation module 15 can collimate the femtosecond laser beam 4 (ultrashort pulse laser beam). The third scanning galvanometer 16 and the third field mirror 17 can focus the collimated femtosecond laser beam 4 (ultrashort pulse laser beam) onto the inner and outer contours of the current layer of the formed part 5. The femtosecond laser beam 4 uses a non-thermal ablation mechanism to perform in-situ cutting and precise shaping of the inner and outer contours of the current layer of the formed part 5.

[0036] The red laser emitted by the red laser 6 is collimated and focused towards a designated position in the powder field to melt the powder 40 at that position. The green or blue laser is collimated and focused towards the molten pool position in the powder field to break up the coarse dendrites in the molten pool. The femtosecond laser emitted by the ultrashort pulse laser 14 is collimated and focused towards the inner and outer contour positions of the current layer of the formed part 5, thereby refining the contour of the formed part 5 in the current layer, removing burrs and other edge marks, and ensuring that the external dimensions of the formed part 5 have ultra-high precision.

[0037] The continuous laser generating device 42 also includes a dynamic beam shaping module 18, which can shape a Gaussian beam into a uniform ring beam, flat-top beam, or Bessel beam using diffractive optical elements or a biconical prism. The dynamic beam shaping module 18 uses a diffractive ring laser beam generator to shape the red light from the fiber laser, or uses a non-diffractive biconical prism to optimize the energy distribution of the Gaussian beam into a uniform ring beam, flat-top beam, or Bessel beam, thereby effectively reducing molten pool spatter and keyhole defects, reducing residual stress within the formed part 5, and improving the forming quality.

[0038] The red laser beam 2 has a wavelength of 1064 nm, the green or blue laser beam has a wavelength of 400-532 nm, and the femtosecond laser beam 4 is an ultrashort pulse laser beam with a wavelength of 780-2526 nm (preferably 1064 nm) and a pulse width of <50 f. The continuous laser generator 42 and the pulsed laser generator 43 are arranged horizontally in a flat manner on the top of the forming chamber 1, or in a staggered, stepped arrangement. The arrangement of the continuous laser generator 42, the pulsed laser generator 43, and the femtosecond laser generator 44 on the top of the forming chamber 1 can be determined according to the available space at the top of the forming chamber 1.

[0039] The upper surface of the bottom plate of the forming chamber 1 is a working plane. The bottom plate of the forming chamber 1 is provided with a mounting port for a forming cylinder 19, and also provides a forming cylinder 19 and a powder spreading device 20. The upper end of the cylinder body of the forming cylinder 19 can be sealed and installed in the mounting port of the forming cylinder 19. The upper end face of the cylinder body of the forming cylinder 19 is horizontally aligned with the working plane. The piston 21 of the forming cylinder is provided with a substrate heating system 22. The forming substrate 23 is placed on the substrate heating system 22 in a circumferential direction. The substrate heating system 22 can intelligently heat the forming substrate 23 based on temperature control technology to maintain its temperature within a set temperature range. The powder spreading device 20 can spread powder 40 in the forming cylinder 19 and ensure that the powder 40 is horizontally aligned with the working plane to form a powder field. The control system controls the lifting and lowering movement of the piston 21 of the forming cylinder, the intermittent powder spreading by the powder spreading device 20, and the constant temperature heating of the forming substrate 23 by the substrate heating system 22.

[0040] A high-efficiency substrate heating system 22 (>350℃) based on temperature control technology was developed for medium-sized SLM equipment. By combining multi-physics fields and simulating and optimizing the thermal field distribution, the metallurgical defects caused by insufficient thermal field in traditional equipment are solved, the forming quality and process stability of high melting point metals are improved, and the stable operation of the whole machine is guaranteed.

[0041] The forming cylinder 19 includes a hot cylinder 24, a cold cylinder 25, and a heat insulation ring 26. The hot cylinder 24, the heat insulation ring 26 made of heat insulation material, and the cold cylinder 25 are fixedly connected from top to bottom to form an integral structure. The piston 21 of the forming cylinder is always located inside the cold cylinder 25. The substrate heating system 22 includes a self-stacked heating base plate 27, an upper cooling base plate 28, an upper heat insulation base plate 29, a connecting block 30, a lower heat insulation base plate 31, and a lower cooling base plate 32. Several heating rods 33 are evenly distributed in an array inside the heating base plate 27. Each heating rod 33 can heat the forming substrate 23 simultaneously. The upper cooling base plate 28 and the lower cooling base plate 32 are equipped with... A cooling circulation water channel 34 is provided, which can rapidly cool the upper cooling base plate 28 and the lower cooling base plate 32. The upper heat insulation base plate 29, made of heat insulation material, can insulate the upper cooling base plate 28 and the upper end of the connecting block 30. The lower heat insulation base plate 31, made of heat insulation material, can insulate the lower end of the connecting block 30 and the lower cooling base plate 32. A powder sealing ring 35 and a gas sealing ring 36 are respectively installed on the upper cooling base plate 28 and the outer circumferential wall of the piston. The powder sealing ring 35 can prevent the powder 40 on the forming substrate 23 from leaking downwards. The gas sealing ring 36 can prevent the inert gas in the forming chamber 1 from leaking outwards along the forming cylinder 19.

[0042] The heating rods 33 on the heating base plate 27 can quickly heat the forming substrate 23. The heating rods 33 are evenly distributed in an array to ensure rapid and uniform heating, so that the powder 40 in the forming cylinder 19 is kept in a suitable temperature range and the thermal field is optimized. At the same time, the upper cooling base plate 28 and the upper heat insulation base plate 29 initially reduce the downward conduction of heat to avoid the connecting block 30 from overheating. Then, the lower heat insulation base plate 31 and the lower cooling base plate 32 further cool down the heat to prevent the heat from being transferred to the piston and affecting the piston performance and service life. By installing a powder sealing ring 35 on the side wall of the upper cooling base plate 28, the powder 40 inside the upper end of the forming cylinder 19 is sealed and blocked, preventing it from leaking downwards. By installing a gas sealing ring 36 on the side wall of the lower cooling base plate 32, the inert gas inside the forming chamber 1 is sealed, preventing it from leaking outwards and also preventing outside air from entering the forming chamber 1, ensuring the quality of the formed part 5 and preventing explosions. Both the powder sealing ring 35 and the gas sealing ring 36 are installed on the cooling base plate, which can prevent them from failing due to high temperature. The cylinder body of the forming cylinder 19 is composed of a hot cylinder body 24, a cold cylinder body 25 and a heat insulation ring 26, so that the piston always operates in a low temperature environment. The heat in the hot field is transferred downwards to the piston through the cylinder body of the forming cylinder 19, and the upper end of the forming cylinder 19 is prevented from affecting the temperature in the hot field due to heat transfer. In order to keep the hot cylinder body 24 warm, heat insulation material can also be covered on the outside of the hot cylinder body 24 to prevent the heat in the hot field from dissipating outwards.

[0043] The heating base plate 27 is also equipped with a temperature sensor, which can sense the temperature of the forming substrate 23 in real time. The temperature sensor can transmit its sensing signal to the control system, which controls the heating rod 33 to start or stop or adjust the heating efficiency of the heating rod 33. By using the temperature sensor to sense the temperature of the forming substrate 23 in real time, the temperature of the upper thermal field of the forming cylinder 19 is kept stable, preferably fluctuating within ±5 degrees, avoiding excessively high or low temperatures and creating a constant temperature effect.

[0044] The forming chamber 1 is provided with an air inlet 37 and an air outlet 38 on its two opposite side walls. Inert gas can enter the forming chamber 1 through the air inlet 37 and carry away the dust in the forming chamber 1 through the air outlet 38. The bottom plate of the forming chamber 1 is provided with two recycling cylinder 39 mounting ports. The two recycling cylinder 39 mounting ports are located on both sides of the forming cylinder 19 mounting port along the movement direction of the powder spreading device 20. The recycling cylinder 39 can be sealed and installed in the two recycling cylinder 39 mounting ports. During the reciprocating movement of the powder spreading device 20, excess powder 40 can be scraped into the recycling cylinder 39 for storage. The piston of the recycling cylinder 39 can move up and down to adjust the powder holding space.

[0045] The powder spreading device 20 generally includes a powder spreading box, a movable powder box, and a scraper 41. The powder spreading box is used to store a large amount of powder 40. The movable powder box is moved to connect with or close the powder spreading box to achieve quantitative feeding. The scraper moves left and right on the working plane to scrape the powder, so that the powder 40 is spread in the forming cylinder 19 according to the designed thickness. Excess powder 40 enters the recycling cylinder 39 for recycling to prevent the excess powder 40 from being scattered by the wind in the forming chamber 1 and to avoid affecting the normal melting and forming of the powder field.

[0046] A multi-wavelength beam collaborative additive manufacturing method includes the following steps:

[0047] Step 1: A molten pool is formed by melting the powder field in forming chamber 1 using a continuous red laser beam with a wavelength of 1064nm;

[0048] Step 2: Use a green or blue pulsed laser beam with a wavelength of 400-532nm to break up dendrites in the semi-molten pool in situ to form equiaxed crystals, thereby increasing the proportion of equiaxed crystals in the molten pool.

[0049] Step 3: The contour of the current layer of the forming part 5 is cut and shaped by a femtosecond laser beam 4 with a wavelength of 780-2526nm. The wavelength of the femtosecond laser beam 4 is preferably 1064nm.

[0050] When the powder field is melted and formed by the red continuous laser beam and the green or blue pulsed laser beam, the forming substrate 23, which is in direct contact with the forming part 5, is heated by the substrate heating system 22 to keep the forming substrate 23 in a constant temperature range of >350°C.

Claims

1. A multi-wavelength beam collaborative additive manufacturing device, characterized in that: The system includes a forming chamber (1), a composite laser emitting device, and a control system. The composite laser emitting device includes a continuous laser generating device (42), a pulsed laser generating device (43), and a femtosecond laser generating device (44). The continuous laser generating device can emit a continuous red laser beam (2) toward the powder field on the working plane of the forming chamber to melt the powder and form a molten pool. The pulsed laser generating device can emit a green or blue pulsed laser beam (3) toward the molten pool of the powder field to realize the post-processing of the molten pool. The femtosecond laser generating device can emit a femtosecond laser beam (4) to cut and shape the contour of the formed part (5). The control system can control the continuous laser generating device, the pulsed laser generating device, and the femtosecond laser generating device to start and stop working.

2. The multi-wavelength beam collaborative additive manufacturing equipment according to claim 1, characterized in that: The continuous laser generating device includes a red laser (6), a first collimation module (7), a first scanning galvanometer (8), and a first field mirror (9). The red laser can emit a red laser beam, the first collimation module can collimate the red laser beam, and the first scanning galvanometer and the first field mirror can focus the collimated red laser beam on the forming position of the powder field surface to melt and form the powder. The pulsed laser generating device includes a green or blue laser (10), a second collimation module (11), a second scanning galvanometer (12), and a second field mirror (13). The green or blue laser can emit green or blue pulsed laser beams. The second collimation module can collimate the green or blue pulsed laser beams. The second scanning galvanometer and the second field mirror can focus the collimated green or blue pulsed laser beams onto the molten pool position on the powder field surface to break up dendrites in the molten pool. The femtosecond laser generating device includes an ultrashort pulse laser (14), a third collimation module (15), a third scanning galvanometer (16), and a third field mirror (17). The ultrashort pulse laser can emit a femtosecond laser beam, the third collimation module can collimate the femtosecond laser beam, and the third scanning galvanometer and the third field mirror can focus the collimated femtosecond laser beam onto the inner and outer contours of the current layer of the forming part. The femtosecond laser beam uses a non-thermal ablation mechanism to perform in-situ cutting and precise shaping of the inner and outer contours of the current layer of the forming part.

3. The multi-wavelength beam collaborative additive manufacturing equipment according to claim 2, characterized in that: The continuous laser generator also includes a dynamic beam shaping module (18), which can shape a Gaussian beam into a uniform ring beam, a flat-top beam, or a Bessel beam by using diffractive optical elements or a double-cone prism.

4. The multi-wavelength beam collaborative additive manufacturing equipment according to claim 1, 2 or 3, characterized in that: The red laser beam has a wavelength of 1064nm, the green or blue laser beam has a wavelength of 400-532nm, and the femtosecond laser beam is an ultrashort pulse laser beam with a wavelength of 780-2526nm and a pulse width of <50f. The continuous laser generator and the pulse laser generator are arranged horizontally in a flat manner on the top of the forming chamber, or in a staggered, stepped arrangement.

5. The multi-wavelength beam collaborative additive manufacturing equipment according to claim 1, characterized in that: The upper surface of the bottom plate of the forming chamber is a working plane. The bottom plate of the forming chamber is provided with a forming cylinder mounting port, and also provides a forming cylinder (19) and a powder spreading device (20). The upper end of the forming cylinder body can be sealed and installed in the forming cylinder mounting port. The upper end face of the forming cylinder body is horizontally aligned with the working plane. The piston (21) of the forming cylinder is provided with a substrate heating system (22). The forming substrate (23) is placed on the substrate heating system in a circumferential direction. The substrate heating system can intelligently heat the forming substrate based on temperature control technology to keep its temperature within the set temperature range. The powder spreading device can spread powder in the forming cylinder and ensure that the powder is horizontally aligned with the working plane to form a powder field. The control system controls the piston lifting and lowering movement of the forming cylinder, the intermittent powder spreading of the powder spreading device, and the constant temperature heating of the forming substrate by the substrate heating system.

6. The multi-wavelength beam collaborative additive manufacturing equipment according to claim 5, characterized in that: The forming cylinder includes a hot cylinder (24), a cold cylinder (25), and a heat insulation ring (26). The hot cylinder, the heat insulation ring made of heat insulation material, and the cold cylinder are fixedly connected from top to bottom to form an integral structure. The piston of the forming cylinder is always located in the cold cylinder. The substrate heating system includes a self-stacked heating base plate (27), an upper cooling base plate (28), an upper heat insulation base plate (29), a connecting block (30), a lower heat insulation base plate (31), and a lower cooling base plate (32). Several heating rods (33) are evenly distributed in an array inside the heating base plate. Each heating rod can heat the forming substrate synchronously. The upper cooling base plate and the lower cooling base plate are provided with cooling circulation water channels (34), which can quickly cool the upper cooling base plate and the lower cooling base plate. The upper heat insulation base plate made of heat insulation material can insulate the upper cooling base plate and the upper end of the connecting block. The lower heat insulation base plate made of heat insulation material can insulate the lower end of the connecting block and the lower cooling base plate. The upper cooling base plate and the outer circumferential wall of the piston are respectively equipped with powder sealing ring (35) and gas sealing ring (36). The powder sealing ring can prevent the powder on the forming substrate from leaking downwards. The gas sealing ring can prevent the inert gas in the forming chamber from leaking outwards along the forming cylinder.

7. The multi-wavelength beam collaborative additive manufacturing equipment according to claim 6, characterized in that: The heating base plate is also equipped with a temperature sensor, which can sense the temperature of the formed substrate in real time. The temperature sensor can transmit its sensing signal to the control system, which controls the heating rod to start or stop or adjust the heating efficiency of the heating rod.

8. The multi-wavelength beam collaborative additive manufacturing equipment according to claim 5, characterized in that: The forming chamber is provided with an air inlet (37) and an air outlet (38) on its two opposite side walls. Inert gas can enter the forming chamber through the air inlet and carry away the dust in the forming chamber through the air outlet. The bottom plate of the forming chamber is provided with two recycling cylinder installation ports. The two recycling cylinder installation ports are located on both sides of the forming cylinder installation port along the direction of movement of the powder spreading device. The two recycling cylinder installation ports can be sealed and installed with recycling cylinders. During the reciprocating motion of the powder spreading device, excess powder (40) can be scraped into the recycling cylinder for storage. The piston of the recycling cylinder can move up and down to adjust the powder holding space.

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