| About this Abstract |
| Meeting |
2020 TMS Annual Meeting & Exhibition
|
| Symposium
|
Additive Manufacturing: Processing Effects on Microstructure and Material Performance
|
| Presentation Title |
Micro-mechanical Characterization of Directed Energy Deposited 316L Stainless Steel with Hierarchical Microstructure |
| Author(s) |
Baolong Zheng, Xin Wang, Sen Jiang, Bingqing Chen, Jiayu Liang, Shuai Huang, Yizhang Zhou, Enrique J. Lavernia, Julie M. Schoenung |
| On-Site Speaker (Planned) |
Baolong Zheng |
| Abstract Scope |
The evolution of microstructure that evolves during Directed Energy Deposition (DED) is rendered inhomogeneous due to complex thermal and fluid gradients in the melt pool. We applied DED to 316L stainless steel and report on the formation of an interesting hierarchical microstructure that evolves during the mesh-like laser scanning patterns, as multiple columnar colonies grow in different orientations. We used focused ion beam milling to prepare micron-sized pillars with different cellular orientations and evaluated the mechanical behavior, in compression, as a function of hierarchical microstructure. The yield stress and strain hardening varied with cellular orientation. Micro-pillars containing cells with multiple orientations exhibited high yield strength and strain hardening and deformed via the formation of multiple cross-shear bands. The formation of hierarchical microstructure is analyzed based on the thermal behavior and dynamics of the melt pool, and the deformation mechanisms are discussed based on the crystal orientations of the cellular microstructure. |
| Proceedings Inclusion? |
Planned: Supplemental Proceedings volume |