Impurity-induced decohesion in iron grain boundary; A First-principles study

Yamaguchi, Masatake   ; Nishiyama, Yutaka ; Shiga, Motoyuki   ; Kaburaki, Hideo; Matsuzawa, Hiroshi*

First-principles calculations have been performed to simulate the grain boundary decohesion (embrittlement) in ferromagnetic bcc iron (Fe) 3(111) symmetrical tilt grain boundary by adding various impurity or solute atoms (B, C, N, O, Si, P, S, Mn, Ni, Cu) to the boundary. We have successfully derived the segregation energy of the solute atom, tensile strength, and cohesive energy of the grain boundary, which are consistent with many empirical facts.