Behaviour of the initial magnetic permeability of the FeNi alloy after neutron irradiation

The behaviour of the initial magnetic permeability of the FeNi (50-50 at. %) alloy was characterized during linear annealings before and after fast neutron irradiation (E≅ 1 MeV), making use of different frequencies of the applied alternating magnetic field. In the irradiated alloy a remarkable decrease of the initial permeability was observed as well as a gradual annihilation of the radiation-produced defects after successive linear annealings. The radiation simulated an increase in the microhardness due to radiation created vacancies which are annihilated by annealing at temperatures between 400 and 500 sup(0)C. (author)