Analytical characterization of secondary phases and void distributions in an ultrafine-grained ODS Fe–14Cr model alloy

Two model Fe–14Cr alloys, one containing 0.3 wt.% of Y2O3 particles, were fabricated by mechanical alloying of Fe and Cr elemental powders under a He atmosphere. They were subsequently consolidated and thermomechanically treated to produce ultra-fine grained materials. Cr-carbides and oxides were found in both alloys. The oxide dispersion-strengthened (ODS) alloy also contained a fine dispersion of nanoparticles, some of them having a Y–O rich core and a Cr-rich shell. Nanometric sized voids were found in both materials, often attached to secondary phases, dislocations and grain boundaries. Their sizes were significantly smaller in the ODS alloy.