The effect of iron on dislocation evolution in model and commercial zirconium alloys - 2016-0068

Conference · Fri Jul 01 04:00:00 EDT 2016

DOI:https://doi.org/10.1520/STP159720160068· OSTI ID:22788424

Topping, Matthew; Harte, Allan; Frankel, Philipp; Race, Christopher ^[1]; Sundell, Gustav; Thuvander, Mattias; Andren, Hans-Olof ^[2]; Jadernas, Daniel; Tejland, Pia ^[3]; Romero, Javier E. ^[4]; Darby, Edward C. ^[5]; Dumbill, Simon ^[6]; Hallstadius, Lars ^[7]; Preuss, Michael ^[1]

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1. University of Manchester, School of Materials, Materials Performance Centre, Manchester, M13 9PL. (United Kingdom)
2. Chalmers University of Technology, Dept. of Applied Physics, SE-412 96 Goteborg (Sweden)
3. Studsvik Nuclear AB, SE-611 82 Nykoping, (Sweden)
4. Westinghouse Electric Company, Columbia, SC (United States)
5. Rolls-Royce, Derby, DE21 7XX (United Kingdom)
6. National Nuclear Laboratory, Sellafield, Seascale, Cumbria, CA20 1PG (United Kingdom)
7. Westinghouse Electric Sweden AB, SE-721 63 Vasteras (Sweden)

Although the evolution of irradiation-induced dislocation loops has been well correlated with irradiation-induced growth phenomena, the effect of alloying elements on this evolution remains elusive, especially at low fluences. To develop a more mechanistic understanding of the role iron has on loop formation, we used state-of-the-art techniques to study a proton-irradiated Zr-0.1Fe alloy and proton- and neutron-irradiated Zircaloy-2. The two alloys were irradiated with 2-MeV protons up to 7 dpa at 350 deg. C and Zircaloy-2 up to 14.7 X 10{sup 25} n. m{sup -2}, approximately 24 dpa, in a boiling water reactor at approximately 300 deg. C. Baseline transmission electron microscopy showed that the Zr{sub 3}Fe secondary-phase particles in the binary system were larger and fewer in number than the Zr(Fe,Cr){sub 2} and Zr{sub 2}(Fe,Ni) particles in Zircaloy-2. An analysis of the irradiated binary alloy revealed only limited dissolution of Ze{sub 3}Fe, suggesting little dispersion of iron into the matrix, while at the same time a higher -loop density was observed compared with Zircaloy-2 at equivalent proton dose levels. We also found that the redistribution of iron during irradiation led to the formation of iron nano-clusters. A delay in the onset of -loop nucleation in proton-irradiated Zircaloy-2 compared with the binary alloy was observed. The effect of iron redistributed from secondary-phase particles because of dissolution on the density and morphology of and loops is described. The implication this may have on irradiation-induced growth of zirconium fuel cladding is also discussed. (authors)

• Research Organization: ASTM International, 100 Barr Harbor Drive, P.O. Box C700, West Conshohocken, PA, 19428-2959 (United States)
• OSTI ID: 22788424
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ATOMIC DISPLACEMENTS
BINARY ALLOY SYSTEMS
BWR TYPE REACTORS
CLADDING
DISLOCATIONS
IRON
IRRADIATION
PARTICLES
PROTONS
TRANSMISSION ELECTRON MICROSCOPY
ZIRCALOY 2
ZIRCONIUM