Ostwald Ripening of Nanodispersed Phases in Metal Alloys (review)

Abstract

The review deals with analysis of the kinetics of Ostwald ripening of nanodispersed phases in metal alloys when the growth (dissolution) of the nanoparticles of the reinforcing phase is controlled simultaneously by the  matrix diffusion, diffusion through the dislocation tubes and the rate of the atoms transition through the interphase boundary (Wagner's mechanism of growth). As a rule, different mechanisms of the nanoparticles growth (dissolution) are simultaneously employed in the process of the particles ripening while the number of the mechanisms involved in the growth (one, two or three) depends on various factors such as: chemical composition of the nanodispersed phases, conditions of exploitation (changes in mechanical loads, temperature regimes, environmental conditions), technological conditions of synthesis, etc. The possibility of practical implementation of the proposed mechanisms of growth of nanoparticles in the Ostwald ripening process can be confirmed or declined by a comparison between the experimental and theoretical data. As seen from the comparison between some experimental histograms with the lines built theoretically, the proposed mechanisms of growth of the dispersed phase nanoparticles seem realistic.