The Effect of hydrogen atoms on the screw dislocation mobility in bcc iron; A First-principles study

Itakura, Mitsuhiro  ; Kaburaki, Hideo; Yamaguchi, Masatake   ; Okita, Taira*

The interaction between dislocations and impurity atoms in metals determines various properties of plastic deformation, such as the dependence of the yield stress on the impurity contents. Since the direct observation of atomistic structure of screw dislocation is almost impossible, several hypothetical assumptions have been employed to explain conveniently experimental observations. Recent advancement of computational hardware, as well as the development of elaborated techniques to reduce the size-effect in the first-principles calculation, enabled direct calculations of dislocation-impurity interaction. We have succeeded to evaluate the effect of hydrogen atoms on the dislocation mobility in iron.