Session: 07-01: NDE for Additive Manufacturing
Paper Number: 98280
98280 - Real-Time Additive Manufacturing Quality Enhancement in Pulse Laser-Assisted Metal Directed Energy Deposition
Directed energy deposition (DED)—a type of additive manufacturing (AM) for metals—utilizes a concentrated laser source to melt powder- or wire-shaped materials delivered near to the laser and accomplishes layer-by-layer fusion of materials. The popularity of DED is driven by its ability to print metals, metal-alloy, and functionally gradient materials. DED can also be used for remanufacturing or repairing components to increase their lifespan. Although significant progress has been achieved in the development of DED processes and materials, quality control and enhancement remain one of the most important challenges for the commercialization of DED technology. To address this problem, we have developed a pulse laser-assisted DED method, where a nanosecond pulse laser is incorporated with the DED process and applied onto the melt pool in a real-time manner. The incorporated pulse laser can (1) facilitate the escape of pores before complete solidification and (2) promote fine and equiaxed grain structures. Such effects are achieved by transiently inducing accelerated and turbulent Marangoni flow, shock waves, and cavitation inside the melt pool. Considering the proposed method directly agitates the melt pool during the DED process, its applications are not limited by the size or complexity of the printing target as well as the original tool-path design. Validation DED tests were performed on Ti-6Al-4V samples manufactured in accompany with a pulse laser with various laser power. Experimental results showed that the proposed method achieved a reduction of over 90% in the total pore number, the aspect ratio of the prior-β grains decreased from 3.5 to 2.5, and the maximum value of multiples of uniform distribution of the α phase decreased from 7.0 to 3.5 in the Ti-6Al-4V samples.
Presenting Author: Peipei Liu Korea Advanced Institute of Science and Technology (KAIST)
Real-Time Additive Manufacturing Quality Enhancement in Pulse Laser-Assisted Metal Directed Energy Deposition
Paper Type
Technical Presentation Only