Development of a semi-empirical approach correlating ion- and neutron-induced hardening in Eurofer97 using nanoindentation and crystal plasticity finite element method

An experimentally-based computational methodology is developed to predict the irradiation hardening in materials for nuclear applications, aimed at avoiding neutron irradiation. The results are expected to accelerate the delivery of new research data in nuclear materials science by reducing the time, costs, and resources necessary for neutron irradiation. The effect of ion irradiation on nanohardness is measured with nanoindentation and computationally replicated on the basis of the tensile tests data from neutron-irradiated specimens. Thus, the established procedure aims to interconnect two important phenomena: the effect of ion vs. neutron irradiations on mechanical properties; and the nanocompressive vs. macrotensile deformation. The accuracy of the outcoming results is discussed. The tests performed are used to establish and validate a crystal plasticity finite element method model of irradiated Eurofer97 steel. The constitutive material law is modified with respect to the hardening caused by the neutron irradiation dose and is used to feed the crystal plasticity finite element method model of the nanoindentation process. This consequently allows one to accurately reproduce the experimental hardness–depth values obtained from the ion-irradiated specimen. Eventually, a basic proof of concept is provided, which can be further refined for the prediction of neutron-induced hardening, while working only with ion-irradiated material.