High temperature nanoindentation of iron: experimental and computational study

Tymofii Khvan, L. Noels, Dmitry Terentyev, F. Dencker, D. Stauffer, Ude D. Hangen, Wouter Van Renterghem, Chih-Cheng Chang, Aleksandr Zinovev

Research outputpeer-review


Application of reduced activation ferritic/martensitic (RAFM) steels as the structural material in future fusion reactors requires the knowledge of their mechanical properties under relevant operational conditions i.e. temperatures and irradiation by fast neutrons. Execution of the neutron irradiation and post irradiation examination is expensive and lengthy, therefore experimental and computational solutions to ease the characterization of as-irradiated materials are in the scope of interests of nuclear materials scientific community. Moreover, ion irradiation is considered as one possible way to surrogate high flux neutron irradiation damage. The extraction of the mechanical properties after ion irradiation primarily relies on the nanoindentation techniques and its subsequent post processing to extract engineering relevant information, although some innovative techniques such as compression micropillars and microtensile testing also exist. In this work, we have performed nanoindentation on BCC iron, as the basis material for ferritic steels, by using a new Bruker stage developed for high temperature operation. The obtained results were analyzed by means of crystal plasticity finite element method (CPFEM), whereas the constitutive laws of the material were derived and established by using tensile deformation data, thus providing an interconnection of material’s behavior under compressive and tensile deformations. The microstructural features such as indentation pile-up formation or dislocation density evolution were obtained by using transmission and scanning electron microscopy, and were compared with the predictions derived by the developed CPFEM model. It is demonstrated that a good agreement between the CPFEM and experimental data set, including tensile and compressive loads as well as associated microstructural changes, is obtained at room temperature and elevated temperature tests.
Original languageEnglish
Article number153815
JournalJournal of Nuclear Materials
StatePublished - 24 May 2022

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