|"Correlation between the microstructure and mechanical properties of irradiated Fe-9Cr ODS" Corey Dolph, Matthew Swenson, Janelle Wharry, Transactions of the American Nuclear Society Vol. 110 2014 421-424 Link|
"Plastic zone size for nanoindentation of irradiated Fe-9wt% Cr ODS alloy"
Janelle Wharry, Corey Dolph, Douglas da Silva, Matthew Swenson,
Journal of Nuclear Materials
The objective of this study is to determine irradiation effects on the nanoindentation plastic zone morphology in a model Fe–9%Cr ODS alloy. Specimens are irradiated to 50 displacements per atom at 400°C with Fe++ self-ions or to 3 dpa at 500°C with neutrons. The as-received specimen is also studied as a control. The nanoindentation plastic zone size is calculated using two approaches: (1) an analytical model based on the expanding spherical cavity analogy, and (2) finite element modeling (FEM). Plastic zones in all specimen conditions extend radially outward from the indenter, ~4–5 times the tip radius, indicative of fully plastic contact. Non-negligible plastic flow in the radial direction requires the experimentalist to consider the plastic zone morphology when nanoindenting ion-irradiated specimens; a single nanoindent may sample non-uniform irradiation damage, regardless of whether the indent is made top-down or in cross-section. Finally, true stress-strain curves are generated.
"The effects of oxide evolution on mechanical properties in proton- and neutron-irradiated Fe-9%Cr ODS steel"
Matthew Swenson, Corey Dolph, Janelle Wharry,
Journal of Nuclear Materials
The objective of this study is to evaluate the effect of irradiation on the strengthening mechanisms of a model Fe-9%Cr oxide dispersion strengthened steel. The alloy was irradiated with protons or neutrons to a dose of 3 displacements per atoms at 500 °C. Nanoindentation was used to measure strengthening due to irradiation, with neutron irradiation causing a greater increase in yield strength than proton irradiation. The irradiated microstructures were characterized using transmission electron microscopy and atom probe tomography (APT). Cluster analysis reveals solute migration from the Y-Ti-O-rich nanoclusters to the surrounding matrix after both irradiations, though the effect is more pronounced in the neutron-irradiated specimen. Because the dissolved oxygen atoms occupy interstitial sites in the iron matrix, they contribute significantly to solid solution strengthening. The dispersed barrier hardening model relates microstructure evolution to the change in yield strength, but is only accurate if solid solution contributions to strengthening are considered simultaneously.
|"Correlation between the microstructure and mechanical properties of irradiated Fe-9Cr ODS" Corey Dolph, American Nuclear Society Annual Meeting [unknown]|
|"Irradiation-induced microstructure and mechanical property evolution in an Fe-9Cr ODS alloy" Corey Dolph, Peter Hosemann, 8th International Conference on Processing & Manufacturing of Advanced Materials (THERMEC) [unknown]|