Orientation relationships and interface structure of α′-Cr nanoclusters embedded in α-Fe matrix after α–α′ demixing in neutron irradiated Oxide Dispersion Strengthened material

A nanoscale characterization of neutron irradiated Oxide Dispersion Strengthened (ODS) alloys has been used to reveal the α–α′ demixing and the population of (Y, Ti, O) nanoparticles. Multivariate statistical analysis (MSA) processed energy filtered transmission electron microscopy (EFTEM) efficiently reveals the location of all nanophases. The α–α′ demixing did not only lead to the systematic formation of cube-on-cube semi-coherent Cr rich clusters but also to misfitting misoriented semi-coherent particles satisfying the orientation relationship [100]Cr//[111]Fe and [100]Cr//[112]Fe. The misorientation angle between the semi-coherent directions < 110 >Fe and < 110 >Cr was found to be 17°.

► α'-Cr rich phases are formed in 14Cr ODS material under neutron irradiation.
► EF-TEM combined with MSA enables to image these nanophases.
► High-resolution TEM show semi-coherency of the α'-Cr-particles.