Recovery of Irradiated Fe-Al-N Alloys

Two kinds of Fe-Al-N alloy were irradiated in the JRR-2 reactor with neutron doses of 1–2×1019 n/cm2 at about 60°C. Using internal friction and torsion test techniques, the atomistic behavior of the structure was studied through observation of the changes brought to the mechanical properties by neutron irradiation and subsequent annealing. The internal friction measurements revealed that irradiation brought about release of nitrogen from Fe8N and AlN. Moreover, the damping curves indicated, upon analysis, the existence of two new peaks, at −120° and −145°C. With annealing, recovery of radiation hardening started from a temperature between 150° and 200°C, and terminated by −350°C.