Advanced Characterization of Materials for Nuclear, Radiation, and Extreme Environments: Data Intensive and Correlative Methods
Sponsored by: TMS Nuclear Materials Committee
Program Organizers: Cody Dennett, Commonwealth Fusion Systems; Samuel Briggs, Oregon State University; Christopher Barr, Department Of Energy; Michael Short, Massachusetts Institute of Technology; Janelle Wharry, Purdue University; Cheng Sun, Clemson University; Caitlin Kohnert, Los Alamos National Laboratory; Emily Aradi, University of Manchester; Khalid Hattar, University of Tennessee Knoxville
Wednesday 8:00 AM
October 20, 2021
Room: A215
Location: Greater Columbus Convention Center
Session Chair: Janelle Wharry, Purdue University; Kevin Field, University of Michigan
8:00 AM Invited
Correlated Scattering and Microscopy Techniques for In-situ and Ex-situ Rapid Clustering Determination in Activated Materials: Kevin Field1; Samuel Briggs2; Caleb Massey3; Dalong Zhang4; Kenneth Littrell3; 1University of Michigan; 2Oregon State University; 3Oak Ridge National Laboratory; 4Pacific Northwest National Laboratory
Materials exposed to extreme environments such as nuclear reactor operating conditions can undergo significant materials evolution with nano-scale clustering of solutes being a critical response. This evolution ultimately leads to gross changes in engineering properties, and thus must be characterized. Unique to nuclear reactor exposure is that samples will become activated, presenting a human-safety risk and unique instrument challenges. Here, we will present and discuss the multi-year development of a correlated scattering and microscopy approach capable of both ex-situ and in-situ post-irradiation annealing that uses specialized methods to handle highly activated samples without loss in data collection and analysis fidelity. The approach will be discussed using Cr-rich/O-rich clustering in ferritic matrices exposed to irradiation conditions common in nuclear power reactors. It will be shown that the correlated characterization pathway provides a rapid method to develop a robust understanding of clustering in these materials placed in extreme environments.
8:20 AM Invited
Imaging Nanostructural Heterogeneities and Vacancy Supersaturation in Ni-20Cr after Corrosion in Molten Salt: Yang Yang1; Weiyue Zhou2; Shen Yin3; Sarah Wang4; Qin Yu3; Matthew J. Olszta5; Daniel K. Schreiber5; Jim Ciston3; Robert O. Ritchie3; Mark Asta3; Ju Li2; Michael P. Short2; Andrew M. Minor3; 1Pennsylvania State University; 2MIT; 3Lawrence Berkeley National Laboratory; 4UCB; 5PNNL
Extreme environments (e.g., radiation damage and corrosion) can drive materials out of their equilibrium states, leading to the dynamical evolution of nanostructural heterogeneities. These processes include chemical segregation, void nucleation, and strain localization, etc. A fundamental understanding of how different kinds of heterogeneities develop and interact with each other is critical for the development of more damage-tolerant materials in harsh environments. However, the progress on this has been hindered by the difficulty of characterizing certain kinds of nanostructural heterogeneities. Here, using a correlative electron microscopy approach by combining focused-ion-beam lift out, three-dimensional (3D) electron tomography, and four-dimensional scanning transmission electron microscopy (4D-STEM), we report on the characterization of the nanostructural heterogeneities in Ni-20Cr alloy after molten-salt corrosion. We attempt to explain how defect transport near the grain boundaries induces void growth and how the void morphology is affected by the nonequilibrium point-defect concentrations and the local strain ‘hot spots'.
8:40 AM
Now On-Demand Only - Multi-scale Characterization of Silicon Carbide Oxidation: Adam Bratten1; Haiming Wen1; Visharad Jalan1; 1Missiouri University of Science and Technology
Due to its excellent high-temperature properties and stability, silicon carbide (SiC) is being considered for applications in high-temperature gas reactors, light-water reactors, and fusion platforms. In air-ingress accident scenarios, structural SiC components may be subjected to hot air in excess of 1000 °C. SiC-coated surrogate fuel particles were oxidized in oxygen-based mixtures of gases with oxygen partial pressure ranging from 0.0002 to 0.2 atm and temperatures ranging from 1000 to 1600 °C. The oxidized particles were characterized via scanning electron microscopy (SEM), focused ion beam (FIB), transmission electron microscopy (TEM), and atom probe tomography (APT). Various microstructural features were studied in the oxide scale, including surface roughness, scale growth kinetics, and devitrification behavior, corresponding to different oxygen partial pressures, oxidation temperatures, and times. The diffusion behavior of carbon, oxygen, and silicon were analyzed with respect to oxidation temperature. Insights into the mechanisms of SiC oxidation were obtained.
9:00 AM
Europa Lander Contamination Control: Materials Testing and Numerical Simulation in a Flight Like Environment: Anthony Wong1; 1Jet Propulsion Lab, California Institute of Technology
The Jovian moon Europa has a rocky core, a massive global ocean, and an icy surface crust. Using Earth experiences as an analog, anywhere we find liquid water, we find life, making Europa an ideal target to search for biological signatures. Europa Lander is a proposed exploration spacecraft that would land on the moon's icy surface, providing an exceptional platform from which to probe for biosignatures. The surface of Europa poses considerable challenges to such a spacecraft, from self and sampling site contamination to extreme cold and radiation environments. In order to prevent, mitigate, and characterize this contamination we will deploy a series of design implementations, experimental materials analyses in flight like environments, and modeling efforts. A capstone of JPL’s materials testing capabilities includes the recent design and implementation of a materials outgassing test capable of simulating the low temperature and high radiation environment present on Europa’s surface.
9:20 AM
A Closer Observation to the Precipitation Behavior of Proton Irradiated Dual Phase 308L Weldment Filler Materials: Zhen Li1; Xun Zhan1; Weicheng Zhong1; Benjamin Sutton2; Brent Heuser1; 1University of Illinois at Urbana-Champaign; 2Electric Power Research Institute
Selective irradiation behaviors in proton irradiated dual phase 308L filler of 508-304 weldment were investigated by advanced characterization techniques. Ni-Si enriched clusters were observed under SEM, TEM, STEM-EDS, HR-STEM and APT in proton irradiated γ austenite, while G phase M6Ni16Si7 precipitates were seen in δ ferrite. Compositional analysis on G phase and Ni-Si cluster with STEM-EDS and APT data was compared. APT can yield accuracy results while analyzing nano-sized point of interest. Unlike G phase in proton irradiated δ ferrite, Ni-Si cluster in proton irradiated γ austenite is not rich in Mn. Both STEM-EDS and APT line-scan profiles on Ni-Si cluster showed that the Fe and Cr concentration variation between matrix γ austenite and Ni-Si cluster is not as sharp as those between matrix δ ferrite and G phase. Further, HR-STEM imaging indicated that the lattice parameter of these Ni-Si enriched cluster is coherent to that of γ austenite.