To the theory of Ostwald ripening in metallic alloys

Abstract

The mechanism of growth (dissolution) of nanoparticles controlled simultaneously by the matrix diffusion, diffusion along dislocations, and the rate of the passage of atoms through the interphase boundary (by the rate of formation of interatomic bonds) has been studied in alloys of CuNiAl and AlLi metallic systems at the stage of Ostwald ripening. An expression for the nanoparticle-size distribution function has been obtained, which was calculated based on the dependence of the rate of growth on three fluxes, i.e., diffusion flux j_V, dislocation flux j_d, and kinetic flux j_i. A comparison of the experimental histograms with the theoretically calculated curves indicates their good agreement, which can indicate the opportunity of the realization in practice of the proposed mechanism of growth of nanoparticles in alloys of metallic systems.