Modelling of Microstructural Transformations in the Systems Subject to Radiation Influence

Formalism is developed for description of microstructure transformations and phase separation in systems under irradiation. Investigation is made within the scope of the crystal phase-field method. This approach allows one to simulate materials on the molecular-dynamics spatial scales but on the diffusive-dynamics temporal scales. Considering a model for a periodic one-component system driven by both competing stochastic fluxes–thermally-stimulated and external ballistic mixing flues of atoms, conditions of microstructure-transformations’ appearance are determined. Analysis of the system on a mesoscopic level for a binary equiatomic system is performed. Reentrant character of phase-separation process is revealed. For systems with transient dynamics, for instance, with incommensurable time scales of propagation of disturbances, which are characterized by the memory effects, at presence of fluctuations of lengths of jumps of the atoms knocked-on by high-energy particles, occurrence of pattern-selection processes is revealed.