"In situ microstructural evolution in face-centered and body-centered cubic complex concentrated solid-solution alloys under heavy ion irradiation"
Michael Moorehead, Calvin Parkin, Mohamed Elbakhshwan, Jing Hu, Wei-Ying Chen, Meimei Li, Lingfeng He, Kumar Sridharan, Adrien Couet,
This study characterizes the microstructural evolution of single-phase complex concentrated solid- solution alloy (CSA) compositions under heavy ion irradiation with the goal of evaluating mecha- nisms for CSA radiation tolerance in advanced fission systems. Three such alloys, Cr 18 Fe 27 Mn 27 Ni 28 , Cr 15 Fe 35 Mn 15 Ni 35 , and equimolar NbTaTiV, along with reference materials (pure Ni and E90 for the Cr- FeMnNi family and pure V for NbTaTiV) were irradiated at 50 K and 773 K with 1 MeV Kr ++ ions to vari- ous levels of displacements per atom (dpa) using in-situ transmission electron microscopy. Cryogenic irra- diation resulted in small defect clusters and faulted dislocation loops as large as 12 nm in face-centered cubic (FCC) CSAs. With thermal diffusion suppressed at cryogenic temperatures, defect densities were lower in all CSAs than in their less compositionally complex reference materials indicating that point defect production is reduced during the displacement cascade stage. High temperature irradiation of the two FCC CSA resulted in the formation of interstitial dislocation loops which by 2 dpa grew to an average size of 27 nm in Cr 18 Fe 27 Mn 27 Ni 28 and 10 nm in Cr 15 Fe 35 Mn 15 Ni 35 . This difference in loop growth kinet- ics was attributed to the difference in Mn-content due to its effect on the nucleation rate by increasing vacancy mobility or reducing the stacking-fault energy.#171118
"Investigating the stability of second phase particles in Zr-Nb alloys under irradiation"
Guanze He, Junliang Liu, Kexue Li, Jing Hu, Anamul Haq Mir, Sergio Lozano-Perez, Chris Grovenor,
Journal of Nuclear Materials
The stability of the β-Nb Second Phase Particles (SPPs) in two types of Zr–Nb alloys (recrystallised Zr-1.0Nb and Zr-2.5Nb) was studied by in-situ heavy ion irradiation in a transmission electron microscope (TEM), combined with ex-situ analysis by energy dispersive x-ray spectroscopy (EDX). TEM thin foils were irradiated by 1 MeV Kr+ ions at four different temperatures from 50 K to 873 K, and by 350 keV Kr+ ions at different doses up to 39dpa. The change in size of individual β-Nb SPPs has been measured quantitatively, and the degradation mechanisms under irradiation at different temperatures discussed. It has been shown that the Nb redistribution between the SPPs and the Zr matrix is governed both by radiation induced mixing and local diffusion in the surrounding Zr matrix. Under the radiation conditions reported in this study, the β-Nb SPPs have shown remarkably stability against irradiation, and the extent of Nb redistribution between the SPPs and Zr matrix is very limited under all experimental conditions.
"Irradiation-induced amorphization in the zirconium suboxide on Zr-0.5Nb alloys"
Junliang Liu, Guanze He, Jing Hu, Zhao Shen, Mark Kirk, Meimei Li, Ed Ryan, Pete Baldo, Sergio Lozano-Perez, Chris Grovenor,
Journal of Nuclear Materials
226 - 231
We report for the first time the observation of irradiation-induced amorphization of the zirconium suboxide formed during aqueous corrosion of Zr-0.5Nb alloys. High-resolution transmission electron microscopy results reveal amorphization of the hexagonal-ZrO suboxide under heavy ion irradiation at cryogenic temperatures. This irradiation-induced amorphization behaviour is discussed in relation to the arrangement of oxygen interstitials and the formation of stable superlattices. The sensitivity of the suboxide to irradiation damage can lead to phase changes and the accumulation of defects near the oxide/metal interface, which needs to be taken into account in the development of mechanistic models addressing radiation-assisted acceleration of corrosion rates in zirconium alloys.
|"In Situ Dual-Beam Ion Irradiation with Transmission Electrom Microscopy" Meimei Li, Jing Hu, ANS Annual Meeting 2018 June 15-18, (2018)|
|"Microstructural Characterization of High-entropy Alloy Ion Irradiated at Cryogenic Temperatures" Michael Moorehead, Calvin Parkin, Lingfeng He, Jing Hu, Meimei Li, Adrien Couet, Kumar Sridharan, TMS 2019 March 10-14, (2019)|
|"Study of Niobium clustering in Zr-1.0%Nb alloy irradiated with Kr2+ ions or neutrons to ~9 dpa at 310 °C" Matthew Swenson, Saheed Adisa, Jing Hu, TMS 2020 Annual Meeting February 23-27, (2020)|
This NSUF Profile is 35
Authored an NSUF-supported publication
Presented an NSUF-supported publication
Submitted an RTE Proposal to NSUF
Awarded an RTE Proposal
Collaborated on 3+ RTE Proposals
Characterization and modeling of secondary phase evolution in an irradiated Zr-1.0Nb alloy - FY 2018 RTE 2nd Call, #318
Controlling the kinetics of radiation induced crystallization in nanoceramics by doping - FY 2018 RTE 2nd Call, #334
In situ ion irradiation of second phase particles in zirconium fuel cladding - FY 2017 RTE 2nd Call, #215
In-situ separate effect studies of thermal and radiation effects on Xe diffusion in alpha-U and U-10Zr. - FY 2019 RTE 1st Call, #377