“From imaging to microstructural quantification: Clustering behavior in irradiated Fe-Cr alloys”
The Fe-Cr system is the basis for most of structural steels currently considered for the nuclear applications. While simple in appearance, it presents experimental and theoretical challenges that if solved would provide unique insights into the processes controlling microstructure evolution under irradiation. Experimentally, Cr is a slow diffusing element in α-Fe, which precludes studying the precipitation of the Cr-rich α′ phase under thermal conditions for temperatures < 400 C. Alternatively, irradiation may be a mean to accelerate diffusion-controlled processes and access α′ precipitation in the low temperature regime. However, the irradiated microstructures appear to be strongly dependent on irradiation conditions suggesting that cascade ballistic mixing may play a significant role on the formation of α′. While defining the role of irradiation on the extent of Cr clustering and precipitation, we will also discuss challenges in quantifying small clusters from atom probe tomography data and approaches taken to address these experimental limitations.