Elastic Fields of Vacancy Voids and Their Interaction with Radiation Defects in Body Centered Cubic Metals Fe and V: Calculation Methods

The calculation of the sink strengths of vacancy voids for radiation defects, which are the parameters of phenomenological models of radiation damage of materials, requires knowledge of the energy of interaction of the radiation defects with the elastic fields created by vacancy voids in the bulk of the material. Direct calculation of the interaction energy by molecular statics demands enormous computational resources and therefore is not suitable for sink strength calculations. In this article, we propose a computationally efficient approach to calculating the interaction energy, which does not introduce a significant error in the calculations. This approach is based on the combined use of different methods: molecular statics is used to calculate the dipole tensors of radiation defects and the elastic strain fields created by vacancy voids, while the interaction of voids with radiation defects (elastic dipoles) is calculated using anisotropic linear elasticity theory. The validity of such an approach is demonstrated by directly comparing its results with the results obtained only by the method of molecular statics, which uses as a test problem the calculation of the interaction between spherical vacancy voids with diameters of 2 and 20 lattice parameters and self-point defects for the BCC metal Fe. Elastic strain fields of the spherical vacancy voids with diameters from 2 to 20 lattice parameters in the BCC metals Fe and V are calculated by molecular statics.