Ductile-brittle behavior at blunted cavities in 3D iron crystals uncovered and covered by copper atoms

Abstract

This paper is devoted to studies of the mechanical response of an atomically blunted cavity uncovered and covered by copper atoms by means 3D molecular dynamic (MD) simulations. The cavity is loaded uni-axially in tension mode I. Our question is how the copper atoms influence the ductile-brittle behavior at the crack front of the blunted cavity in comparison with the blunted cavity in pure bcc iron. We show that the dislocation emission is easier in the Fe–Cu system in comparison with pure bcc iron. However, stability of the blunted cavities seems to be weaker in copper region than in pure bcc iron.