Features of primary radiation damage in Fe–Cr alloy near free surfaces

Abstract

The influence of interfaces on the primary radiation damage in the Fe–10Cr alloy was studied in the framework of the molecular dynamics method. The simulation of atomic displacement cascade evolution near free surfaces with crystallographic indices (110) and (111) was performed. It was revealed that the number of survived point defects sufficiently depends on the region of cascade generation. Atomic displacement cascade near the free surface generates approximately two times more defects than the cascade in the bulk sample with the ideal structure. After the irradiation of the free surfaces the samples contained more vacancies than interstitial atoms. Calculations showed that the crystallographic orientation of the irradiated free surface significantly affects the character of the primary radiation damage of the material. Craters are much more frequently formed at irradiation of the (111) surface. The 1/2 〈111〉 dislocations are formed mainly at irradiation of the (111) surface, and the 〈100〉 dislocations mainly appear at loading the (110) surface.