Dislocation interaction with C in α-Fe: A comparison between atomic simulations and elasticity theory

The interaction of C atoms with a screw and an edge dislocation is modelled at an atomic scale using an empirical Fe–C interatomic potential based on the embedded atom method and molecular statics simulations. Results of atomic simulations are compared with predictions of elasticity theory. It is shown that a quantitative agreement can be obtained between both modelling techniques as long as anisotropic elastic calculations are performed and both the dilatation and the tetragonal distortion induced by the C interstitial are considered. Using isotropic elasticity allows the prediction of the main trends of the interaction, whereas considering only the interstitial dilatation will lead to a wrong interaction.