US-12623289-B2 - Multi-field-assisted laser melting deposition composite additive manufacturing system

US12623289B2US 12623289 B2US12623289 B2US 12623289B2US-12623289-B2

Abstract

The disclosure belongs to the field of advanced manufacturing technology and discloses a multi-field-assisted laser melting deposition composite additive manufacturing system. The system includes a vacuum chamber atmosphere protection module, a laser melting deposition module, an ultrasonic shock peening module, a workpiece transfer module, an auxiliary thermal field induction heating module, a laser shock peening module, and an integrated control module. The vacuum chamber atmosphere protection module, the laser melting deposition module, the ultrasonic shock peening module, the workpiece transfer module, the auxiliary thermal field induction heating module, and the laser shock peening module are electrically connected to the integrated control module individually and are collaboratively controlled by the integrated control module.

Inventors

Wenjing REN
Lianyong Xu
Lei Zhao
Yongdian Han
KANGDA HAO

Assignees

TIANJIN UNIVERSITY

Dates

Publication Date: 20260512
Application Date: 20231024

Claims (10)

1 . A multi-field-assisted laser melting deposition composite additive manufacturing system, comprising a vacuum chamber atmosphere protection module, a laser melting deposition module, an ultrasonic shock peening module, a workpiece transfer module, an auxiliary thermal field induction heating module, a laser shock peening module, and an integrated control module, wherein the vacuum chamber atmosphere protection module comprises a bunker, a vacuum pump, a dust removal and filtering device, a transition chamber, and an inert gas replenishing device are provided outside the bunker and individually communicates with the interior of the bunker, the dust removal and filtering device is further connected to a circulating gas-washing device designed to wash the gas inside the bunker and reintroduce the washed gas into the bunker, the laser melting deposition module is arranged inside the bunker and comprises a deposition head, a translational movement device, a workpiece turntable, a laser, a powder feeding device, and a gas supply device, the translational movement device and the workpiece turntable are fixed within the bunker, the deposition head is positioned on the translational movement device, located above the workpiece turntable, and capable of performing a translational movement on the translational movement device, the laser, the powder feeding device and the gas supply device are all located outside the bunker, the laser is connected to the deposition head via an optical fiber, and the powder feeding device and the gas supply device are individually connected to the deposition head, the ultrasonic shock peening module comprises an ultrasonic shock gun and an ultrasonic generator, the ultrasonic shock gun is fixed on the deposition head, and processing ends of the deposition head and the ultrasonic shock gun face downward toward the workpiece turntable, the ultrasonic generator is located outside the bunker and communicates with the ultrasonic shock gun via an electrical signal, the workpiece transfer module is positioned on the workpiece turntable, and a base plate is affixed to the workpiece transfer module, the workpiece transfer module can move horizontally to transport a molded part to be processed into or out of the transition chamber, the auxiliary thermal field induction heating module is located on one side of the workpiece transfer module and is designed to heat the base plate and/or the molded part, the laser shock peening module is situated outside the bunker and is used for performing laser shock peening on a molded part processed by laser melting deposition within the bunker, and the vacuum chamber atmosphere protection module, the laser melting deposition module, the ultrasonic shock peening module, the workpiece transfer module, the auxiliary thermal field induction heating module, and the laser shock peening module are electrically connected to the integrated control module individually and are collaboratively controlled by the integrated control module.
2 . The multi-field-assisted laser melting deposition composite additive manufacturing system according to claim 1 , wherein the translational movement performed by the deposition head on the translational movement device comprises a left and right movement, a front and rear movement, and an up and down movement, and preferably, the deposition head can move within a movement stroke range of 0 mm to 800 mm in the left and right movement, within a movement stroke range of 0 mm to 800 mm in the front and rear movement and within a movement stroke range of 0 mm to 800 mm in the up and down movement on the translational movement device.
3 . The multi-field-assisted laser melting deposition composite additive manufacturing system according to claim 1 , wherein the workpiece turntable comprises a base, two supporting parts, and a working platform from bottom to top, the base is fixed on an inner bottom surface of the bunker through a vertically-arranged rotation axis and can rotate 360° around the vertically-arranged rotation axis, the two supporting parts are symmetrically arranged on the base, and the working platform is installed between the two supporting parts and can be flipped forward and backward within a limited angle range, and preferably, the limited angle range is 0° to 95° for backward flipping and 0° to 5° for forward flipping.
4 . The multi-field-assisted laser melting deposition composite additive manufacturing system according to claim 1 , wherein the workpiece transfer module comprises a horizontal sliding table and a base plate locking device from bottom to top, the horizontal sliding table can move horizontally in translation, and the base plate locking device is fixed on the horizontal sliding table for locking the base plate.
5 . The multi-field-assisted laser melting deposition composite additive manufacturing system according to claim 1 , wherein the auxiliary thermal field induction heating module comprises a temperature sensor, an electromagnetic induction coil, a lifting slider rail, and an electromagnetic induction heater, the lifting slider rail is fixed on the workpiece turntable or the bunker, the temperature sensor and the electromagnetic induction coil are both fixed on the lifting slider rail, the lifting slider rail can drive the temperature sensor and the electromagnetic induction coil to move up and down synchronously, the electromagnetic induction heater is located outside the bunker and communicates with the electromagnetic induction coil, and preferably, the temperature sensor is arranged above the electromagnetic induction coil.
6 . The multi-field-assisted laser melting deposition composite additive manufacturing system according to claim 1 , wherein the laser shock peening module comprises a pulse laser, a robot, and a constraint layer laying device, the robot is configured to transport the molded part from the transition chamber to a laser shock peening processing position, the constraint layer laying device is configured to lay a constraint layer on a surface of the molded part, and the pulse laser is configured to perform laser shock peening on the surface of the molded part laid with the constraint layer.
7 . The multi-field-assisted laser melting deposition composite additive manufacturing system according to claim 1 , wherein the transition chamber comprises a transition chamber outer door and a transition chamber inner door symmetrically arranged at a left end of the transition chamber and a right end of the transition chamber and a base plate receiving structure arranged on an inner bottom surface of the transition chamber, wherein the transition chamber inner door is located between the bunker and the transition chamber, the base plate receiving structure is configured to receive the base plate sent into the transition chamber, and the transition chamber outer door, the base plate receiving structure, and the transition chamber inner door all move under the control of the integrated control module.
8 . The multi-field-assisted laser melting deposition composite additive manufacturing system according to claim 1 , wherein a water and oxygen monitoring device is further arranged on an inner wall of the bunker for real-time monitoring of a water and oxygen content in the bunker.
9 . The multi-field-assisted laser melting deposition composite additive manufacturing system according to claim 8 , wherein a pressure monitoring device is further arranged on the inner wall of the bunker for real-time monitoring of an air pressure in the bunker.
10 . The multi-field-assisted laser melting deposition composite additive manufacturing system according to claim 1 , wherein a pressure inside the bunker is between 10 mbar and 100 mbar in a vacuum state.

Description

BACKGROUND Technical Field The disclosure belongs to the field of advanced manufacturing technology, specifically concerning a multi-field-assisted laser melting deposition composite additive manufacturing system. Description of Related Art Additive manufacturing (AM) is a groundbreaking advanced manufacturing technology capable of directly 3D-printing parts from digital models layer by layer. Compared to conventional or subtractive manufacturing methods such as casting, forging, and machining, additive manufacturing significantly increases design freedom and reduces production time. Laser melting deposition (LMD) is an additive manufacturing technology based on laser cladding. It achieves rapid near-net-shape-forming manufacturing of parts by melting coaxially fed powder with a laser and depositing it layer by layer. In addition to the common advantages of additive manufacturing, laser melting deposition is less constrained by structural size, provides high molding efficiency, and is capable of rapidly molding and repairing gradient/composite materials. Laser melting deposition is currently one of the most typical metal additive manufacturing methods and has applications in automobile manufacturing, aerospace, shipbuilding, and other fields. However, at present, effective laser melting deposition additive manufacturing primarily applies to metals like 316 stainless steel, 718 nickel-based alloys, TiAl6V4, etc., limiting the types of materials that can be used. High-performance materials like titanium-aluminum alloys, high-entropy alloys, and high-strength aluminum alloys often exhibit defects during the laser melting deposition process, resulting in printed parts with overall performance inferior to those manufacturing using equal/subtractive methods with the same material. The main issues stem from the inherent characteristics of conventional laser melting deposition: (1) The conventional process relies on a coaxial gas supply to provide inert gas protection during processing, but this protection is often inadequate, leading to air or inert gas infiltration into the molten pool causing pore defects. For oxygen-sensitive materials like aluminum alloys, a solid oxide film may form on the deposition surface during cooling, resulting in defects such as lack of fusion and slag inclusions between deposition layers. (2) In the laser additive manufacturing process, the high-energy laser interacts with metals briefly, with a small contact area. The “melting-solidification-cooling” process imposes large temperature gradients and cooling rates on the metals, causing significant internal stress, which results in cracks and fracturing. (3) Temperature gradients and cooling rates are key thermodynamic factors affecting the final microstructure of the molded part in the laser melting deposition process. The local microstructure experiences complex thermal effects as a result the deposited metal undergoes remelting and repeated thermal cycles during layer-by-layer stacking. This thermal effect is influenced not only by printing parameters but also by factors like part structure, size, and ambient temperature. Unreasonable temperature gradients and cooling rates lead to coarse columnar crystals and uneven microstructures, causing anisotropy, poor mechanical properties, and poor stability in deposited parts. These issues significantly limit the practical application of additive manufacturing technology for large and complex metal parts. Addressing these problems and improving gas protection internal stress control, defect reduction, microstructure optimization, isotropy, and mechanical properties have become crucial for fabricating large and complex metal components using additive manufacturing. To address these challenges, the related art has explored ultrasonic shock peening (CN111590189A and CN111451504A) and laser shock peening (CN113976925A and CN112264618A) in additive manufacturing processes. By applying layer-by-layer shock treatments in additive manufacturing, these methods have shown promise in improving issues like coarse grain structure, increasing dislocation density, eliminating harmful residual stress, and enhancing comprehensive mechanical properties. However, these disclosed technologies can only address individual problems, and they employ single-field assisted methods to address issues in additive manufacturing. Challenges such as inadequate gas protection during additive manufacturing, effective control of temperature gradients and cooling rates, microstructure optimization, effective suppression of cracks and harmful internal stress, and the elimination of anisotropy cannot be fully resolved using these methods alone. SUMMARY Recognizing the shortcomings of the related art, the disclosure aims to introduce a multi-field-assisted laser melting deposition composite additive manufacturing system to address issues such as poor gas protection during additive manufacturing, difficulties in controlling temper