Emergent Materials under Extremes and Decisive In Situ Characterizations: Extreme Conditions
Sponsored by: ACerS Basic Science Division
Program Organizers: Xiaofeng Guo, Washington State University; Hongwu Xu, Los Alamos National Laboratory; Xujie Lu, Center for High Pressure Science & Technology Advanced Research; Hua Zhou, Argonne National Laboratory; Judith Driscoll, University of Cambridge
Wednesday 2:00 PM
October 12, 2022
Room: 325
Location: David L. Lawrence Convention Center
Session Chair: Xiaofeng Guo, Washington State University
2:00 PM Invited
In Situ Microstructural Characterization of Metallic Nuclear Fuels: Tiankai Yao1; Kaustubh Bawane1; Sriram Vijayan2; Amey Khanolkar1; Fidelma Giulia Di Lemma1; Lingfeng He1; 1Idaho National Laboratory; 2The Ohio State University
Metallic nuclear fuels are ideal for fast reactors because of higher densities of fissile and fertile materials than other fuel forms. The phase evolution and fuel-cladding chemical interaction in metallic fuels in nuclear reactor environments are not yet well understood. In this work, we design in situ transmission electron microscopy (TEM) experiments using a micro electromechanical system (MEMS) based heating stage and study microstructural evolution in two metallic fuel systems, U-Zr and U-Mo as a function of temperature. The thermally driven phase changes are characterized by using electron diffraction and ChemiSTEM techniques. We further modify MEMS-based heating stage to study thermal gradient effects on microstructural evolution in these metallic fuels. In addition, in situ laser ultrasonic measurements supplement in situ TEM characterization to monitor phase transitions during thermal processing. These in situ characterization experiments provide better mechanistic understanding in microstructural and chemical evolution in metallic fuels under non-equilibrium conditions.
2:30 PM Invited
The Role of Anisotropic Diffusion on the Bubble/Void Superlattice Formation in Metals: Cheng Sun1; 1Idaho National Laboratory
The ordering of irradiation-induced bubbles and voids leads to the formation of three-dimensional superlattices, an effective mechanism for gas storage. Defect superlattices have been reported in a variety of materials systems under irradiation, however, their formation mechanisms remain controversial. In this presentation, we will summarize our recent research progress on the understanding of bubble and void superlattice formation in fcc and bcc metals under irradiation. The role of materials’ anisotropic diffusion on the formation of defect superlattices is studied using advanced experimental and modeling tools. Understanding the mechanisms that govern the defect self-organization is essential for predicting the lifetime of materials in irradiation environments.
3:00 PM Invited
Understanding Surface Radiation Damage in Concentrated Solid-Solution Alloys by Nanoindentation: Youxing Chen1; Liuqing Yang1; Yanwen Zhang2; Nan Li3; 1University of North Carolina at Charlotte; 2Oak Ridge National Laboratory; 3Los Alamos National Laboratory
Concentrated solid-solution alloys (CSAs) are a new type of alloy material with good mechanical properties and excellent radiation resistance. For heavy ion irradiation studies on these alloys, traditional mechanical tests (e.g., tensile tests) cannot measure the properties due to limited volume. Nanoindentation is an ideal tool to characterize surface properties of heavy ion irradiated alloys. In this study, we will employ nanoindentation to investigate the radiation damage in a wide spectrum of irradiated Ni-based CSAs, including (a) single-phase single-crystal CSAs (e.g, NiCo, NiCoFeCr) in which microstructural effects are excluded and (b) dual-phase CSAs (CrFeMnNi and AlCrFeMnNi) in which phase boundaries are contributing to the radiation damage and deformation. The role of solid solution and microstructure to radiation damage, and the corresponding deformation mechanisms will be discussed.
3:30 PM Break
3:50 PM Invited
In-Situ High Temperature Neutron and X-ray Studies of Corrosion Kinetics and Salt Properties: Li Liu1; Emily Stefanis1; Ryan Bedell1; 1Rensselaer Polytechnic Institute
In Concentrating Solar Power, we are developing neutron and X-ray measurements for in-situ interface corrosion kinetics and molten salt properties. This research will provide fundamental data for material selection including the molten salt systems for both nuclear and solar applications. The presentation will focus on the development of in-situ neutron techniques (and X-ray comparable results) for fundamental understanding of the mechanisms of molten salt corrosion, and the micro-structural response of containment alloys thereto, to measure the surface corrosion kinetics. We are working on realization and initial application of in-situ techniques for measuring molten salt fundamental properties including molten salt structure, dynamics, and salt density, etc. and the micro-structural and -chemical response of containment alloys to corrosive molten salt environments. While we are designing and manufacturing sample environments for harsh environments (high temperature and corrosive), they will provide great first-of-the-kind experimental data for molten salt systems.
4:20 PM
Electrochemical Deposition with Redox Replacement of Lanthanum with Uranium in Molten LiCl-KCl: Jeffrey Eakin1; Daniel Molina1; Haluk Beyenal1; Cornelius Ivory1; 1Washignton State University
Pulsed electrodeposition with replacement (EDRR) is an electrochemical technique that has been used in aqueous media to recover precious metals from solutions that have an excess of less valuable metals. In this work, EDRR is explored for the first time in a molten salt medium for the electrochemical recovery of pure uranium in the presence of lanthanide fission products represented by lanthanum. In each EDRR cycle, after a short electrodeposition pulse the deposited lanthanum is spontaneously replaced by uranium at open circuit. After repeated cycles, pure uranium metal was obtained on a tungsten electrode immersed in LiCl-KCl melt that contained 1 wt.% lanthanum chloride – 0.15 wt.% uranium (IV) chloride. SEM-EDS analysis revealed uranium particles with an average size of 1 μm and well-defined geometrical shapes. This pulsed technique can be used to recover pure uranium at low concentrations after the electrowinning of uranium has been completed at constant potential.
4:40 PM
Influence of Cementite Morphology and Its Orientation on Deformation and Fracture of Pearlitic Steel Wire: Ki-Seong Park1; Saurabh Pawar1; Abhishek Singh1; Da-Hye Shin2; Dong-Chan Jang2; Choong-ryeol Lee3; Jun-Hark Park3; Il-Heon Son3; Sang-yoon Lee3; Shi Hoon Choi1; 1Sunchon National University; 2Korea Advanced Institute of Science and Technology; 3Technical Research Lab., POSCO
To improve the durability of pearlitic steel wire manufactured through the wire drawing process, it is essential to understand the effect of microstructure on the deformation and fracture behavior of pearlite. The pearlitic steel wire is composed of a layered structure of ferrite and cementite, and in particular, the width and spacing of the cementite are very densely formed at the level of about 50 nm. In this study, a micro-pillar compression test was performed to experimentally observe the effect of microstructure on the deformation and fracture behavior of pearlitic steel wires. Based on the difference in hardness values measured by nanoindentation test, microstructures were classified into 5 types, and micro-pillars were prepared using FIB based on the classified microstructure. Meanwhile, finite element analysis was performed considering the fracture model for simulating effect of cementite on deformation and fracture behavior during compression of pearlitic steel in the form of micro-pillars.
5:00 PM Concluding Comments