Abstract
Materials processed by fusion-based additive manufacturing (AM) typically exhibit relatively high dislocation densities, along with cellular structures and elemental segregation. This representative structural feature significantly influences material performance; however, post-mortem microstructure characterizations of AM materials cannot capture the dynamic evolution of dislocations during the manufacturing process, thereby offering limited mechanism-based guidance for further advancing AM techniques and facilitating the qualification and certification of AM products. In this study, we conduct operando high-energy synchrotron X-ray diffraction experiments on wire-laser directed energy deposition of 316 L stainless steel. Through a unique configuration, our operando synchrotron experiments semi-quantitatively probe the dislocation density in solid phases and their dynamic changes during solidification and subsequent cooling. By integrating this advanced synchrotron technique with multi-physics simulation, in-situ neutron diffraction, and multi-scale electron microscopy characterization, our mechanistic study aims to elucidate the effects of rapid cooling and subsequent thermal cycling on the dislocation generation and evolution.
| Original language | English |
|---|---|
| Article number | 4696 |
| Journal | Nature Communications |
| Volume | 16 |
| Issue number | 1 |
| DOIs | |
| State | Published - Dec 2025 |
Funding
The authors would like to thank Alex Deriy, Ali Mashayekhi, and Peter Kenesei at the Advanced Photon Source for their assistance in the synchrotron beamline experiment. We are also grateful for the help from former UVA colleagues Zhongshu Ren and Lilly Balderson. T.S. acknowledges partial support from NSF-DMR. This material is based upon work supported by the National Science Foundation under Grant No. 2427686. This research was performed on APS beam time award(s) ( https://doi.org/10.46936/APS-183365/60011367 ) from the Advanced Photon Source, a U.S. Department of Energy (DOE) Office of Science user facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357. This research also used resources at the Spallation Neutron Source, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory. The beamtime was allocated to VULCAN on proposal number IPTS-30197.