Modelling of the diffusion of self-interstitial atom clusters in Fe-Cr alloys

Dmitry Terentyev (1) , Lorenzo Malerba (2) , Alexander V Barashev (3)

1 RMO
2 RMO
3 University of Liverpool

The results of molecular dynamics simulations of the diffusion of clusters of self-interstitial atoms in Fe-Cr alloys of different Cr content are presented. It is shown that with increasing Cr concentration the cluster diffusivity first decreases and then increases, in accordance with the predictions of a model developed recently, based on molecular static calculations. The minimum diffusivity is found at about 10 at.%Cr for small clusters and it shifts towards lower concentration with increasing cluster size. The migration energy of SIA clusters is found to lie in between the binding energy of a Cr atom with a crowdion and half of it. This indicates that the mechanism of a cluster migration is via the movement of individual crowdions from one Cr atom to another. The values obtained statically are much higher and are argued to be more reliable due to better sampling of different configurations in a bigger simulation box.

Mots clés: Physical Sciences

Dmitry Terentyev, Lorenzo Malerba, Alexander V Barashev. Modelling of the diffusion of self-interstitial atom clusters in Fe-Cr alloys. Philosophical Magazine, 2007, 88 (01), pp.21-29. ⟨10.1080/14786430701727513⟩. ⟨hal-00513842⟩