About this Abstract |
Meeting |
2023 TMS Annual Meeting & Exhibition
|
Symposium
|
Additive Manufacturing of Metals: Applications of Solidification Fundamentals
|
Presentation Title |
Improving Ductility of 316L Stainless Steel by Inducing Melt Pool Instability in Directed Energy Deposition |
Author(s) |
Lin Gao, Wenhao Lin, Zhongshu Ren, Ma Ji, Tao Sun |
On-Site Speaker (Planned) |
Lin Gao |
Abstract Scope |
Developing effective printing strategies to fabricate structural materials with superior mechanical performance is an active research area in metal additive manufacturing (AM). In our work, we applied a wiggle deposition pattern in wire laser-directed energy deposition of 316L stainless steel. The as-built sample exhibits much-improved ductility without compromise of strength. Using multi-physics simulation, operando near-infrared imaging and synchrotron X-ray diffraction, we discovered that the wiggle deposition pattern induces highly dynamic melt flow and oscillating thermal gradient in the melt pool, which interrupts the directional grain growth in the mushy zone and generates considerable grain boundary (GB) protrusions (a.k.a. serrated GBs). This unique GB structure can accommodate intergranular deformation, and therefore improve the tensile property of the sample. We believe the fundamental principle of inducing melt pool instability can be readily implemented in other metal AM processes to further expand the classical strength–ductility envelope of conventional and emerging alloys. |
Proceedings Inclusion? |
Planned: |
Keywords |
Additive Manufacturing, Solidification, Mechanical Properties |