Growth of a brittle crack (0 0 1) in 3D bcc iron crystal with a Cu nano-particle

We present new results of molecular dynamics (MD) in 3D bcc Fe–Cu crystal with embedded central through crack (0 0 1)[1 1 0] of Griffith type loaded in mode I. Such sample geometry and border conditions in MD were chosen to invoke a cleavage crack extension through a bcc Cu nano-particle placed in front of the crack. The stress field and bond breakage caused by the crack and Cu inhomogeneity are analysed on the atomistic level. The character of crack extension and corresponding wave patterns are studied in the Fe–Cu system. The study is motivated by a question how a small Cu bcc precipitate changes the brittle behavior of the crack in comparison with pure bcc iron loaded in mode I.