Properties of in-core reactor-irradiated amorphous Fe40Ni40B20

Amorphous Fe40Ni40B20 has been exposed to in-core reactor irradiation with fluences of thermal neutrons up to 6.5 x 1019 n cm-2. The nuclear reaction 10B(n,α)7Li + 2.3 MeV, caused by the capture of thermal neutrons, leads to damage levels of up to 26 dpa. Subsequent investigations of the irradiated material by transmission electron microscopy showed that the material remains amorphous under neutron irradiation. Irradiation-induced defects could not be detected. Thermal analysis of these specimens revealed that after irradiation to 6.5 x 1019 n cm-2 the amorphous structure appeared to be less stable with respect to the as-quenched material. Bending tests yielded a drastic loss in ductility already after 1 x 1019 n cm-2. (orig.)