Applying multiscale modeling methods to analysis of systems under irradiation

Work number - M 80 AWARDED

Presented by: Institute of Applied Physics of NAS of Ukraine

Authors: Kharchenko Vasyl(h-index= 13)

               Lysenko Iryna(h-index= 8)

The main goal of this work is a development of a consistent description for microstructure transformation in a framework of multicscale modeling in systems under irradiation.In the submitted cycle of scientific works authors study microstructural transformations in pure materials and binary solid solutions that are subjected to irradiation influence. For a detailed and complete analysis of the dynamics of the processes of ordering, phase separation and pattern formation the authors applied multiscale modeling scheme. The authors analyzed the stability of binary zirconium-based solutions, by changing the concentration of alloying elements within the calculations from first principles. By studying one-component systems that are exposed to irradiation, it is found that the non-equivalence in energy of bombarding particles stimulates the processes of ordering and pattern formation. It is shown that in such systems the size of the structures is defined by irradiation flux and average length of jumps of knocked atoms. By using the reaction rate theory authors perform a detailed analysis of the dynamics and selforganization processes of ensemble of point defects in irradiated materials and the evolution of grain structure in such systems. It is shown that the morphology of clusters of point defects is defined by the irradiation dose rate and temperature. It is shown that an increase in damage rate leads to a decrease in the mean grain size and slows down the growth of grains. Investigating the processes of phase separation of binary solid solutions, subjected to sustained irradiation, it is shown that an intensity of atoms mixing caused by irradiation, and non-equivalence in energy of bombarding particles control the processes of new phase formation. It was shown that irradiation leads to an increase in resistance to plastic deformation andreduceіthe plasticity of the alloy. Bystudying the processes of pattern formation on the surface of irradiated materials subjected to ion-beam sputtering it is found that the morphology of the surface structures and their size can be controlled by the sputtering angle, energy and intensity of incident particles, and fluctuations in irradiation flux and incidence angle.

Publicationscount:17, including 2 monographs, 15 articles (9 - in foreign journals). On the subject of this work 1 PhD thesis was defended and 1 doctoral dissertation was prepared to protection

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