CN-122007451-A - Ultrafast-continuous double-beam green light synergistic powder bed additive manufacturing equipment

CN122007451ACN 122007451 ACN122007451 ACN 122007451ACN-122007451-A

Abstract

The invention belongs to the technical field of 3D printing, and particularly relates to ultrafast-continuous dual-beam green light synergistic powder bed additive manufacturing equipment, which comprises a high-energy green light laser and an ultrafast pulse green light laser, wherein the high-energy green light laser comprises a laser body; the laser scanning device comprises a beam combining lens, a scanning galvanometer system, an anti-reflection protection structure, a forming cylinder and a powder supply system, wherein the beam combining lens is used for combining laser beams, the anti-reflection protection structure is arranged on a light path in the scanning galvanometer system and comprises an anti-reflection coating and a light path isolation module. The scheme adopts double green laser beams to carry out cooperative processing so as to simultaneously realize high-efficiency forming of high-reflection metal and active inhibition of internal defects. The first beam of high-energy green laser takes charge of melting powder to form a stable molten pool by utilizing the advantages of short wavelength and high material absorptivity, and completes basic forming. The second beam of ultra-fast green laser immediately after the second beam of ultra-fast green laser is used for impacting a fusing area which is not completely solidified in a pulse mode, so that grains are effectively refined, microcracks are restrained, holes are compacted, and in-situ modification of a microstructure of a material is realized.

Inventors

ZHOU LIUCHENG
HE PENG
Pan Xinlei
LI BIN
YANG HONGWEI
SUN XIN
WANG WENHE

Assignees

中国人民解放军空军工程大学

Dates

Publication Date: 20260512
Application Date: 20260227

Claims (10)

1. An ultrafast-continuous dual-beam green light synergistic powder bed additive manufacturing device, characterized by comprising: The laser light source comprises a high-energy green laser (1) and an ultra-fast pulse green laser (2), wherein the high-energy green laser (1) is used for emitting continuous or long-pulse laser, and the ultra-fast pulse green laser (2) is used for emitting ultra-short pulse laser; the beam combining lens (3) is arranged on the light emitting side of the laser light source and is used for combining the laser emitted by the high-energy green laser (1) and the ultrafast pulse green laser (2); The scanning galvanometer system (4) is arranged on the light emitting side of the beam combining lens (3) and comprises an X-axis galvanometer (41), a Y-axis galvanometer and a field lens (43); The anti-reflection protection structure is arranged on an optical path in the scanning galvanometer system (4) and comprises an anti-reflection coating (9) and an optical path isolation module (10), wherein the anti-reflection coating (9) is arranged on the light emergent sides of the X-axis galvanometer (41) and the Y-axis galvanometer, and the optical path isolation module (10) is arranged on the optical path of the ultra-short pulse laser and is used for absorbing or deflecting redundant reflected light; The forming cylinder (6) is arranged below the scanning galvanometer system (4), and the emergent light of the scanning galvanometer system (4) is directed to the powder bed plane in the forming cylinder (6); And the powder supply system (7) is arranged at the forming cylinder (6) and is used for uniformly paving a powder layer into the forming cylinder (6).
2. The ultrafast-continuous dual-beam green light collaborative powder bed additive manufacturing apparatus according to claim 1, further comprising a synchronization control unit (5), wherein the synchronization control unit (5) is electrically connected with the laser light source and the scanning galvanometer system (4) to control start and stop of the laser light source and deflection of the scanning galvanometer system (4).
3. The ultrafast-continuous dual-beam green light collaborative powder bed additive manufacturing equipment according to claim 2, wherein the synchronous control unit (5) performs accurate time sequence management on a laser light source, a molten pool is formed by fusing a high-energy green light laser (1), and then impact strengthening is performed on the molten pool by an ultrafast pulse green light laser (2).
4. The ultra-fast-continuous dual-beam green-light synergistic powder bed additive manufacturing apparatus as claimed in claim 3, wherein the high-energy green laser (1) emits light beam faster than the ultra-fast pulsed green laser (2) and has a time interval Δt, and the setting of Δt is performed to ensure that the molten pool is in a critical phase of high-temperature plastic state but complete solidification has not yet occurred.
5. The ultrafast-continuous dual-beam green light synergistic powder bed additive manufacturing equipment as claimed in claim 4, wherein the particle size of the powder layer is 15-53 μm, the thickness of the powder paved for one time is 30-80 μm, the ultrafast laser parameters are generally 5-70W, the scanning speed is 500-8000mm/s, and the weight frequency is 10-100khz.
6. The ultrafast-continuous dual-beam green light synergistic powder bed additive manufacturing apparatus as claimed in claim 2, wherein a motor for controlling deflection of the X-axis galvanometer (41) and a motor for controlling deflection of the Y-axis galvanometer are electrically connected with the synchronous control unit (5), and deflection angles of the two are controlled by the synchronous control unit (5) to drive the combined dual beams to move along a predetermined track on a powder bed plane.
7. The ultrafast-continuous dual-beam green light cooperative powder bed additive manufacturing apparatus of claim 1, wherein an equipment main body frame (8) is provided above the forming cylinder (6), and the scanning galvanometer system (4) is detachably mounted on the equipment main body frame (8).
8. The ultrafast-continuous dual-beam green light synergistic powder bed additive manufacturing equipment according to claim 1, wherein field mirrors (43) are arranged on the light emitting side of the X-axis vibrating mirror (41) and the light emitting side of the Y-axis vibrating mirror, and an anti-reflection coating (9) is arranged on the surface of each field mirror (43).
9. The ultrafast-continuous dual beam green light cooperative powder bed additive manufacturing apparatus of claim 8, wherein the anti-reflective coating (9) is a highly reflective coating for an ultrafast green light wavelength of 532 nm.
10. The ultrafast-continuous dual-beam green light collaborative powder bed additive manufacturing apparatus according to claim 1, wherein the optical path isolation module (10) is a faraday isolator or absorber.

Description

Ultrafast-continuous double-beam green light synergistic powder bed additive manufacturing equipment Technical Field The invention belongs to the technical field of 3D printing, and particularly relates to ultrafast-continuous double-beam green light synergistic powder bed additive manufacturing equipment. Background In 3D metal printing technology, conventional devices employing high-energy infrared lasers face inherent technical bottlenecks for the fabrication of high-reflectivity metallic materials (e.g., copper, gold, and alloys thereof). Because of the extremely high laser reflectivity of the material in the infrared band, the energy absorption efficiency is low, the stability of a molten pool is poor, the forming process is difficult, and a compact formed piece is difficult to obtain. To enhance the laser absorptivity of highly reflective materials, the prior art has developed dual laser forge printing techniques using high energy green light devices, or a combination of infrared and green light. Although this type of method improves the forming feasibility to some extent, it still fails to thoroughly solve the problem of microscopic defects in the fusing process, such as microcracks, pores, and unfused. These defects obviously reduce the mechanical properties and fatigue life of the parts, so that the parts are difficult to meet the severe requirements of high-end equipment such as aerospace, precision instruments and the like on the internal quality and reliability of the parts under extreme working conditions. Therefore, in order to break through the quality bottleneck of the current high-reflection alloy additive manufacturing and realize the direct forming of high-performance and high-reliability workpieces, development of novel composite manufacturing equipment capable of effectively inhibiting defects and improving compactness and performance is urgently needed. The manufacture of high reflectivity metallic materials mainly has the following technical bottlenecks and inherent defects: 1. The energy absorptivity of the infrared laser is extremely low, and when the traditional high-energy infrared laser (such as 1064nm wavelength) is used for processing high-reflectivity metals such as gold, silver, copper and the like, the initial reflectivity of the material to the laser is usually higher than 90%. This results in the vast majority of the laser energy being reflected and not efficiently coupled into the powder, which not only results in extremely low energy utilization, but in more serious cases in the formation of melt pools with difficulty and poor stability, resulting in a large number of unfused defects in the formed part, and even in continuous forming. 2. The processing efficiency and the thermal management of the single green laser are difficult, and although the high-energy green laser can obviously improve the absorptivity of the material to the laser, the single green light source faces the economic and technical challenges of low electro-optical conversion efficiency, high equipment cost, high operation power consumption and the like when realizing the high power density required by deep fusion welding. Meanwhile, the heat input is concentrated, if the process parameters are controlled improperly, the phenomena of splashing, keyhole collapse and spheroidization are easily caused, and instead, air holes and stress concentration are introduced into the material. 3. The infrared-green light double laser system has the defect of cooperative defect control, namely the existing infrared-green light double laser technology (forging printing) combines the high-efficiency fusing of infrared laser and the high absorption characteristic of green laser, but the cooperative control of two lasers with different wavelengths in time sequence and space is not perfect. The mismatch causes insufficient and unstable impact strengthening effect on a molten pool, and can not effectively eliminate micro defects such as microcracks, shrinkage holes and the like generated in the solidification process, so that the fatigue life and mechanical properties of a finished piece still cannot meet the strict requirements of extreme working conditions such as aerospace and the like on the internal quality and reliability of the part. For this reason, it is necessary to design an ultrafast-continuous dual-beam green-light synergistic powder bed additive manufacturing apparatus. Disclosure of Invention In order to solve the problems in the prior art, the scheme provides ultrafast-continuous double-beam green light synergistic powder bed additive manufacturing equipment. The technical scheme adopted by the invention is as follows: An ultrafast-continuous dual beam green synergistic powder bed additive manufacturing apparatus, comprising: The laser light source comprises a high-energy green laser and an ultrafast pulse green laser, wherein the high-energy green laser is used for emitting continuous or long-pulse laser, a