NUMERICAL-SIMULATION OF VOID NUCLEATION IN IRRADIATED METALS

An atomistics-based theory for void nucleation has been used to calculate - for the first time - terminal void number densities for irradiated nickel, type 316 stainless steel, and the Ni-base alloy, PE-16. Both the absolute magnitudes and temperature dependences of the void number densities are in agreement with experiment. The void nucleation parameter, ψ, which governs spontaneous void nucleation was evaluated for the three materials; the results are in agreement with experiment. The critical gas content for rapid void growth was calculated for PE-16 and type 316 stainless steel, and was found to increase from about 10 helium atoms at the lower end of the void swelling range to some 104 atoms at the upper end. The theory was also found to predict re-nucleation of a new distribution of voids after a drop in temperature during irradiation. © 1979.