Quantifying the Glide Resistance to Dislocations in Proton-Irradiated FeCrAl Alloy

The proton irradiation-induced hardening effect of dislocations in C35M FeCrAl alloy on glide resistance was quantified by in-situ micropillar compression testing in a scanning electron microscope (SEM). Irradiation tests with a proton energy of 2 MeV were conducted at room temperature, producing plateau damage of 0.01 and 0.1 displacement per atom (dpa), respectively, and generating high density of dislocation loops with fine size (<10 nm). Single-crystal micropillars were prepared with maximizing Schmid factor for a specific slip system while minimizing the others and then compressed to active one specific slip system to measure the critical resolve shear stress (CRSS) of {110}<111> and {112}<111> slip systems, respectively. The CRSS for these two slip systems increases with increasing irradiation dose. {112}<111> slip system shows larger hardening than {110}<111> slip system. Microstructure characterization after deformation indicates that the hardening effect originates from the pinning effect of irradiation-induced defects on moving dislocations.