Abstract
Model FeCrAl alloys of Fe-10%Cr-5%Al, Fe-12%Cr-4.5%Al, Fe-15%Cr-4%Al and Fe-18%Cr-3%Al (in wt.%) were irradiated with 1MeV Kr++ ions in-situ with transmission electron microscopy to a dose of 2.5 displacements per atom (dpa) at 320oC. In all cases, the microstructural damage consisted of dislocation loops with ½〈111〉 and 〈100〉 Burgers vectors. The proportion of ½〈111〉 dislocation loops varied from ~50% in the Fe-10%Cr-5%Al model alloy and the Fe-18Cr%-3%Al model alloy to a peak of 80% in the model Fe-15%Cr-4.5%Al alloy. The dislocation loop volume density increased with dose for all alloys and showed signs of approaching saturation at 2.5 dpa. The total loop populations at 2.5 dpa had a slight (and possibly insignificant) decline as the chromium content was increased from 10 wt.% to 15 wt.%, but the Fe-18%Cr-3%Al alloy had a dislocation loop population ~50% less than the other model alloys. The largest dislocation loops in each alloy had an image size of close to 20nm in the micrographs, while the median diameters for all alloys ranged from 6nm to 8nm. Nature analysis by the inside-outside method indicated most dislocation loops were interstitial-type.