Theoretical model of interstitial diffusion in solid solution under hypergravity conditions

Abstract

Diffusion of atoms and molecules is usually driven by concentration gradients, with the influence of gravitational energy being negligible. However, for alloying components operating at exceptional rotational speeds, such as engine blades, the resulting centrifugal force significantly impacts element distribution. In hypergravity fields, the gravitational potential becomes comparable to the chemical potential, and these two factors jointly determine the diffusion process in solid solutions. This study establishes a theoretical model to quantify the influence of hypergravity on element diffusion in solids, analogous to centrifugal environments in engineering applications. Element diffusion under hypergravity, combined with different boundary conditions, is analyzed. It is found that gravitational energy in a hypergravity field promotes element diffusion when both are in the same direction. In particular, the effect of the hypergravity field on the diffusion process is determined by the difference between the density of diffusing atoms and one-third of the density of the solid substrate. This newly established model provides a valuable tool for assessing element diffusion in solids under extreme hypergravity conditions.