title: Ballistic effects on the copper precipitation and re-dissolution kinetics in an ion irradiated and thermally annealed Fe-Cu alloy.
abstract: Studies of solute precipitation and precipitate phase stability in nuclear structural materials under concurrent irradiation and heat often lead to contradictory results due to the complex nature of the phenomena which is far from well understood. Here, we present a comprehensive atomistically based continuum model for the copper precipitation and re-dissolution kinetics in an ion irradiated and thermally annealed Fe-0.78 at. % Cu alloy. Our model incorporates thermal and irradiation enhanced diffusion of atomic Cu, clustering of Cu into sub-nanometer and nanometer sized precipitates, thermal dissociation of the precipitates and, in particular, a cascade re-dissolution parameter that has been made available by recent molecular dynamics simulations. Our model suggests that the Cu precipitates may form, re-dissolve, or coarsen under different irradiation and thermal conditions depending on the competition between the thermal and the ballistic effects. The quantitative predictions of our model are compared with available experiments including limited atom probe tomography data acquired in this study. The work highlights the importance of combining thermal and ballistic effects in the understanding of phase stability in extreme nuclear environments.
authors.affiliation: Department of Nuclear Engineering, University of Tennessee, Knoxville, Tennessee 37996, USA.
authors.forename: Donghua
authors.initials: D
authors.lastname: Xu
authors.affiliation: Pacific Northwest National Laboratory, Richland, Washington 99352, USA.
authors.forename: Alicia
authors.initials: A
authors.lastname: Certain
authors.affiliation: Department of Materials Science and Engineering, MIT, Cambridge, Massachusetts 02139, USA.
authors.forename: Hyon-Jee
authors.initials: HJ
authors.lastname: Lee Voigt
authors.affiliation: Department of Engineering Physics, University of Wisconsin, Madison, Wisconsin 53706, USA.
authors.forename: Todd
authors.initials: T
authors.lastname: Allen
authors.affiliation: Department of Nuclear Engineering, University of Tennessee, Knoxville, Tennessee 37996, USA.
authors.forename: Brian D
authors.initials: BD
authors.lastname: Wirth