Introducing chemistry in atomistic kinetic Monte Carlo simulations of Fe alloys under irradiation

The evolution of alloy microstructures under non-equilibrium conditions such as irradiation is ail important academic as well-industrial issue. Atomistic kinetic Monte Carlo is one of the most versatile method which can be used to simulate the evolution of a complex microstructure at the atomic scale, dealing with elementary atomic mechanisms. It was developed more than 40 years ago to investigate diffusion events via the motion of a single vacancy, and the introduction of hetero-interstitials or self-interstitials in the models is yet under development. This paper presents the key ingredients of the model, i.e. the algorithm, and some methods implemented to determine the cohesive energy as well as the activation energy. For purpose of simplicity and speed of calculations, most of the models developed so far apply to idealized lattices and model alloys, for example binary alloys. The extension of the models to more complex alloys is recent and ail example of the simulation of inulti-component Fe-CuNiMnSi alloys representative of pressure vessel steels is thus presented in more details. In particular, the adjustment procedures of the cohesive model are demonstrated as well as the validation of the model for vacancies and self-interstitials on thermal ageing and isochronal annealing experiments. (C) 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim