NSUF 26-5618: In-Situ Synchrotron X-Ray Diffraction Study of Neutron Irradiated AM 316L Stainless Steel Under Uniaxial Tension
This project aims to investigate radiation-induced microstructural and mechanical changes in laser powder bed fusion (LPBF) 316L stainless steel (SS) following low-dose neutron irradiation (~0.2 dpa) at 300°C in the High Flux Isotope Reactor (HFIR). Additive manufacturing (AM) offers the possibility of geometries unrealizable through conventional manufacturing methods. LPBF 316L stainless steel has become a promising candidate for in-reactor applications due to its flexibility in component design and accelerated manufacturing timelines. However, the unique microstructure produced by rapid solidification characterized by dislocation cell structures and solute segregation (e.g., Ni, Cr, Si) at sub-grain boundaries introduces spatial heterogeneity which is not present in conventionally manufactured alloys. The mechanical and microstructural stability of these features under neutron irradiation remains uncertain. The objective of this study is to assess the evolution of internal stress states, dislocation dynamics, and irradiation-induced alterations in deformation mechanisms during mechanical loading of LPBF 316L SS. We hypothesize that irradiation induced stress relaxation will be higher in the AM material and thus contributes to the greater degradation in mechanical behavior. High-energy diffraction microscopy (HEDM) enables real-time mapping of lattice strain, peak broadening (indicative of dislocation density), and residual stress evolution. In-situ tensile testing will be conducted at the 1-ID or 20-ID beamline of the Advanced Photon Source (APS) at Argonne National Laboratory (ANL) using synchrotron X-ray diffraction. These data are critical to understanding the fundamental deformation behavior of irradiated LPBF 316L SS.
Additional Info
| Field | Value |
|---|---|
| Awarded Institution | University of Illinois Urbana-Champaign |
| DOI | 10.46936/NSUF/60017671 |
| Embargo End Date | 2028-04-22 |
| Facility Tech Lead | Kory Linton, Wei-Ying Chen |
| NSUF Call | FY 2026 RTE 1st Call |
| PI | Mahmud Hasan Ovi |
| PIE Facilities | Activated Materials Laboratory-Advanced Photon Source (1-ID, 20-ID beamlines) |
| Prep Facilities | Low Activation Materials Design and Analysis Laboratory |
| Project Member | Dr. Stephen Taller, R&D Staff Scientist - Oak Ridge National Laboratory (https://orcid.org/0000-0002-7323-4786) |
| Project Member | Dr. Caleb Massey, R&D Staff Member - Oak Ridge National Laboratory (https://orcid.org/0000-0003-1093-3958) |
| Project Member | Professor James Stubbins, Willett Professor - University of Illinois (https://orcid.org/0000-0003-4559-5848) |
| Project Member | Dr. Timothy Lach, R&D Staff Member - Oak Ridge National Laboratory (https://orcid.org/0000-0002-4745-4179) |
| Project Member | Mr. Mahmud Hasan Ovi, Graduate Research Assistant - University of Illinois Urbana-Champaign (https://orcid.org/0000-0003-2457-9590) |
| Project Type | RTE |