Abstract
Ni-based superalloys are promising materials for high-temperature molten salt (MS) energy generation and storage. Studying morphological and chemical evolution of pure Ni in MS provides fundamental knowledge for MS technologies and corrosion mitigation. Here, real-time 3D morphological changes of Ni microparticles in molten KCl-MgCl2 were studied by operando synchrotron X-ray nano-tomography at 700°C. Rapid Ni particle agglomeration occurred, without significant chemical reactions, such as oxide or chloride formation. The morphological growth evolved differently from classical coarsening or sintering behaviors and occurred nonuniformly, with other regions showing slight dissolution of Ni. Ni nanoparticles were found to be dispersed in many areas of the samples, either from microparticle dissolution or other radiation-induced nanoparticle formation mechanisms. This study discusses important factors, i.e., thermal gradient, amounts of salt and metals, and radiation effect, that influence morphological changes of materials in MS, critical for fundamental understanding of material–MS interactions as well as for practical applications.
| Original language | English |
|---|---|
| Pages (from-to) | 1006-1018 |
| Number of pages | 13 |
| Journal | JOM |
| Volume | 75 |
| Issue number | 4 |
| DOIs | |
| State | Published - Apr 2023 |
Funding
Funding was provided by the U.S. Department of Energy Office of Science, Office of Basic Energy Sciences under contracts DE-SC0012704 and DE-AC05-00OR22725. This work was supported as part of the Molten Salts in Extreme Environments (MSEE) Energy Frontier Research Center, funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences. BNL and ORNL are operated under DOE Contracts DE-SC0012704, and DE-AC05-00OR22725, respectively. Work at Stony Brook University was supported by MSEE through a subcontract from BNL. This research used resources and the Full Field X-ray Imaging (FXI, 18-ID) beamline of the National Synchrotron Light Source II, a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Brookhaven National Laboratory under Contract DE-SC0012704. We thank Dr. James Wishart, Dr. Simon Pimblott, Prof. Katsuyo Thornton, Prof. Adrien Couet, and Prof. Anatoly Frenkel for helpful discussions as part of the MSEE activities, as well as their great insights contributing to the interpretation and future work planning mentioned in this manuscript. We thank Bobby Layne for helping with the heater and experimental setup. Current and former Chen-Wiegart group members are acknowledged for helping the beamtime: Xiaoyin Zheng, Varun Ravi Kankanallu, Charles Clark, and Cheng-Chu Chung.
| Funders | Funder number |
|---|---|
| MSEE | |
| U.S. Department of Energy | DE-SC0012704 |
| U.S. Department of Energy | |
| Office of Science | |
| Basic Energy Sciences | DE-AC05-00OR22725 |
| Basic Energy Sciences | |
| Brookhaven National Laboratory |