Published online by Cambridge University Press: 16 February 2011
Microstructural examinations have been performed on a series of binary Fe-Cr alloys irradiated to 200 dpa at 425°C in a fast breeder reactor. The alloy compositions rangedfrom 3% to 18% Cr in 3% Cr increments, and the irradiation temperature corresponded to the peak swelling condition for this alloy class. Density measurements showed swelling levels as high as 7.4%, with the highest swelling found in the Fe-9Cr and Fe-6Cr alloys. Microstructural examinations revealed that the highest swelling conditions contained welldeveloped voids, often as large as 100 nm, and a dislocation network comprised of both a2 <111> and <100> Burgers vectors. Swelling was lower in the other alloys, and the swelling reduction could be correlated with increased precipitation. These results are considered in light of the current theories for low swelling in ferritic alloys, but no theory is available to completely explain the results.