First-principles study on effect of Re, Os and 5d solutes on dislocation motion in W alloys

Tsuru, Tomohito   ; Suzudo, Tomoaki   ; Wakeda, Masato*; Ogata, Shigenobu*; Daryl, C.*

Tungsten (W) is a potential candidate for plasma-facing materials in fusion reactors due to its high melting point and high thermal conductivity. Neutron irradiation transmutes W into other 5d metals such as rhenium (Re) and osmium (Os). We have so far carried out first-principles and kinetic Monte Carlo calculations to investigate the formation of radiation defects such as voids and radiation-induced precipitates in W alloys. In the present study, we investigate in detail the effects of Re and other 5d solutes on the interaction energy with a screw dislocation and the energy barrier for the dislocation motion through DFT calculations. Finally, solution hardening/softening behavior is reproduced by combining the DFT results with a theoretical model.