Changes In The Distribution And Morphology of γ' Precipitate In Neutron Irradiated Pe-16
Nimonic PE-16 is a γ' hardened, austenitic alloy which has been chosen as a candidate for fuel element cladding and structural component applications in future breeder reactors due to its attractive high temperature strength properties and swelling resistance. The γ' phase is an ordered fee structure of LI2 symmetry having a Ni3(Al, Ti) composition, and is generally found as a finely distributed, spherical, coherent precipitate.Cylindrical (∽6 mm diam x ∽10 mm length) specimens were machined from rod and then solution treated at 1313 K for 2 hr followed by an aging treatment of 2 hr at 1073 K plus 16 hr at 973 K. Specimens were irradiated in the EBR-II at temperatures in the range 650 to 823 K and to fluences in the range 1.2 to 4.0 x 1026 n.m-2 (E >0.1 MeV). Details of the swelling and mechanical properties will be reported elsewhere.