Abstract
The development of materials for breeder blankets of fusion reactors requires a comprehensive understanding of their behavior under extreme operating conditions, including exposure to high temperatures, intense neutron irradiation, and contact with chemically active gaseous environments. In this context, metal beryllides, particularly Be 12 Ti and Be 12 Cr, are of significant interest and are considered as promising functional materials for breeder blanket applications. In this work, a phenomenological model of beryllide corrosion in water vapor is proposed based on the analysis of experimental data on the high-temperature corrosion of chromium beryllide (water vapor pressure ranging from 10 to 10,000 Pa and temperatures between 373 and 1100 К), as well as relevant literature data. The model assumes diffusion-controlled growth of a BeO oxide layer and enables the correlation of the experimentally observed kinetics of mass change and gas evolution with effective parameters describing beryllium diffusion through the oxide. It was found that a single set of model parameters provides an adequate description of all the experiments performed. The parameters, including the pre-exponential factor D 0 (8·10 -8 m 2 s −1 ) and activation energy E d (115 kJ·mol −1 ) in the Arrhenius expression for the diffusion coefficient, as well as C 0 (1.75 mol·m −3 ), corresponding to the equilibrium concentration of mobile beryllium carriers in BeO at the metal-oxide interface, were reliably determined through fitting to the experimental data.