Understanding irradiation-induced nanoprecipitation in zirconium alloys using parallel TEM and APT

A. Harte, R. Prasath Babu, C. A. Hirst, T. L. Martin, P. A.J. Bagot, M. P. Moody, P. Frankel, J. Romero, L. Hallstadius, E. C. Darby, M. Preuss

Research output: Contribution to journalArticleResearchpeer-review

5 Citations (Scopus)

Abstract

We investigate nano-scale irradiation-induced precipitation in a Zr–Sn–Fe–Cr–Ni-alloy (Zircaloy-2) by combining atom probe tomography (APT) for chemical detail with scanning transmission electron microscopy (STEM) and high resolution energy dispersive X-ray (EDX) spectroscopy for wider context and complimentary and correlative TEM diffraction techniques for crystallographic relationships. We find that Fe– and Cr-rich nano-rods precipitate in Zircaloy-2 following proton irradiation at 350 °C to a low dose of ∼2 dpa. The long-axis of the nano-rods are aligned in a direction 12–15° from the Zr matrix 〈0001〉 align in the basal plane and are of width 1.5–5 nm. Smaller rods are of APT-determined composition Zr4(Fe0.67Cr0.33), tending towards Zr3(Fe0.69Cr0.31) as the rod volume increases to > ∼400 nm3, in agreement with STEM-EDX determination of composition resembling that of Zr3Fe with Cr replacing some of the Fe. The Fe/Cr ratio has been shown to increase with distance from the nearest partially-dissolved Zr(Fe,Cr)2 phase particle. The nucleation of nano rods has implications for macroscopic irradiation-induced deformation phenomena, irradiation-induced hardening and the evolution of dislocation loops and other defects.

Original languageEnglish
Pages (from-to)460-471
Number of pages12
JournalJournal of Nuclear Materials
Volume510
DOIs
Publication statusPublished - Nov 2018
Externally publishedYes

Keywords

  • Atom probe tomography
  • Irradiation
  • Nano precipitation
  • Transmission electron microscopy
  • Zirconium

Cite this