Neutron irradiation effects in Fe and Fe-Cr at 300 °C

• Published in: Acta materialia Vol. 111; no. C; pp. 407 - 416
• Main Authors: Chen, Wei-Ying, Miao, Yinbin, Gan, Jian, Okuniewski, Maria A., Maloy, Stuart A., Stubbins, James F.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Ltd 01.06.2016; Elsevier
• Subjects: Dislocation loop; Fe-Cr; Hardness; Irradiation; MATERIALS SCIENCE; Neutron; Orowan; Void; Orowan; Fe-Cr; Irradiation; Dislocation loop; Void; Hardness; Neutron
• ISSN: 1359-6454; 1873-2453
• DOI: 10.1016/j.actamat.2016.03.060

Fe and Fe-Cr (Cr = 10–16 at.%) specimens were neutron-irradiated at 300 °C to 0.01, 0.1 and 1 dpa. The TEM observations indicated that the Cr significantly reduced the mobility of dislocation loops and suppressed vacancy clustering, leading to distinct damage microstructures between Fe and Fe-Cr. Irradiation-induced dislocation loops in Fe were heterogeneously observed in the vicinity of grown-in dislocations, whereas the loop distribution observed in Fe-Cr is much more uniform. Voids were observed in the irradiated Fe samples, but not in irradiated Fe-Cr samples. Increasing Cr content in Fe-Cr results in a higher density, and a smaller size of irradiation-induced dislocation loops. Orowan mechanism was used to correlate the observed microstructure and hardening, which showed that the hardening in Fe-Cr can be attributed to the formation of dislocation loops and α′ precipitates. Addition of Cr in Fe suppressed the mobility of mobile 1/2 dislocation loops and increased the proportion of immobile dislocation loops, leading to a transition of loop distribution from highly heterogeneous to uniform. [Display omitted]