Evolution of dislocation structure in neutron irradiated Zircaloy-2 studied by synchrotron x-ray diffraction peak profile analysis

DOI: 10.1016/j.actamat.2016.12.031

Authors: T. Seymour (University of Manchester) , P. Frankel (University of Manchester) , L. Balogh (Department of Mechanical and Materials Engineering, Queen's University) , T. Ungár (The University of Manchester; Eötvös University Budapest) , S. P. Thompson (Diamond Light Source) , D. Jädernäs (Studsvik Nuclear AB) , J. Romero (Westinghouse Electric Company) , L. Hallstadius (Westinghouse Electric Sweden AB) , M. R. Daymond (Department of Mechanical and Materials Engineering, Queen's University) , G. Ribárik (Queen's University; Université de Lorraine) , M. Preuss (University of Manchester)
Co-authored by industrial partner: Yes

Type: Journal Paper
Journal: Acta Materialia , VOL 126 , PAGES 102 - 113

State: Published (Approved)
Published: March 2017
Diamond Proposal Number(s): 8395 , 10006

Abstract: Dislocation structures in neutron irradiated Zircaloy-2 fuel cladding and channel material have been characterized by means of high-resolution synchrotron x-ray diffraction combined with whole peak profile analysis and by transmission electron microscopy (TEM). The samples available for this characterization were taken from high burnup fuel assemblies and offer insight into the evolution of the dislocation structure after the formation of dislocation loops containing a cc component. Absolute dislocation density values are about 4–15 times higher for the whole peak profile compared to TEM analysis. Most interestingly, the diffraction analysis suggests that the total dislocation density, as well as the aa loop density, increases with fluence for the cladding material type. This trend is also inferred from a Williamson-Hall representation but contradicts the TEM observations. The cc loop density evolution is more complicated and doesn't display any particular trend. In addition, the diffraction analysis highlights the presence of well-developed shoulders adjacent to the basal reflections and noticeable peak asymmetry particularly for the channel samples that experienced slightly lower operation temperatures than the clad. The findings are discussed in respect of the perceived irradiation induced growth mechanisms in Zr alloys.

Journal Keywords: Synchrotron diffraction; Peak profile analysis; Irradiation effects; Dislocation density; Zirconium alloys

Diamond Keywords: Alloys

Subject Areas: Materials


Instruments: I11-High Resolution Powder Diffraction

Added On: 04/01/2017 12:02

Documents:
1-s2.0-S1359645416309673-main.pdf

Discipline Tags:

Radioactive Materials Materials Science Metallurgy

Technical Tags:

Diffraction X-ray Powder Diffraction