The mechanical properties of an Alloy 718 window after irradiation in a spallation environment

A double-shelled Alloy 718 window was irradiated at the Los Alamos Neutron Science Center (LANSCE) with a 1 mA, 800 MeV proton beam to a maximum dose of 20 dpa at a calculated irradiation temperature of 400°C. After irradiation, the window was visually inspected in hot cells at the Chemical and Metallurgical Research (CMR) facility at the Los Alamos National Laboratory (LANL) and cut into strips for analysis. Microhardness and optical metallography were performed at the LANL hot cells and tensile testing and gamma measurements were performed at Forschungszentrum Jülich. The results of these analyses are presented in comparison with previous results obtained on similarly irradiated Alloy 718 components. A crack that occurred in-service was also examined and possible failure modes are discussed.