The influence of chromium on the radiation damage resistance of the iron based alloys was studied using conventional positron annihilation lifetime spectroscopy. Experimental data evaluation was supported by the former theoretical calculation of positron lifetimes in the studied materials and well-defined types of defects. For this purpose, density functional theory computation method was applied. The spectrum of used 22Na positron source was decomposed into discrete fractions to better calculate efficiency of near surface layers study. For the experimental simulation of a-radiation and obtaining of defined cascade collisions in the materials, helium implantation was used. Different level of the implanted dose (6.24 x 1017 to 3.12 x 1018/cm2) corresponds to local damage up to 90dpa acquired in a thin <1μm region. Experimental measurements were performed using the positron annihilation lifetime spectroscopy technique on 4 different Fe-Cr binary alloys (2.36; 4.62; 8.39; 11.62wt%Cr). The results showed that chromium had a significant effect on the size and density of the implanted defects and specific Cr content should prevent the vacancy clusters formation.

Ion Implantation Induced Defects in Fe-Cr Alloys Studied by Conventional Positron Annihilation Lifetime Spectroscopy. V.Kršjak, S.Sojak, V.Slugeň, M.Petriska: Journal of Physics - Conference Series, 2011, 265[1], 012014