Thermodynamic estimation of possibility of proceeding a physicochemical processes in surface layers of heat-resistant alloys under irradiation by power ion beam with nsec duration

Equilibrium thermodynamic methods have been used for evaluation of possibilities of physical and chemical processes in surface layers of complex heterogeneous systems under high-power ion beam of nanosecond duration. Estimations of irradiation conditions for VT25U and EP718ID alloys when reactions of melting, sublimation, decomposition and mainphase atomization take place are carried out. After irradiation at chosen conditions (160 and 300 keV ion energy, 20-180 A/cm² current density, 50-100 ns duration and 1-20 pulse number) investigations of physical and chemical state of high temperature alloys surface layers were carried out using Auger electron spectroscopy, scanning electron microscopy, X-ray and metallography analysis. Calculation results agree well with the experimental ones and explain the processes of carbides fraction, phases decomposition and cracks formation in surface layers.