Ostwald Ripening of Diffusion-Limited Small-Size Precipitates at Grain Boundaries

Abstract

The paper describes a theoretical study of the Ostwald ripening of two-dimensional small-size precipitates of a newly formed phase at the grain boundary of finite thickness, taking into account the diffusion of impurity atoms from the grain interior to the grain boundary. The precipitate growth is believed to be limited by the impurity-atom diffusion in the grain boundary. The asymptotic time dependences are found for the average and critical precipitate radius, supersaturation of solid solution of impurity atoms in the grain boundary, precipitate size distribution function, precipitate density, and for the factor of grain boundary filling with precipitates. A discussion of the limits of validity of obtained results is given.

Keywords

• Supersaturated Solid Solutions
• Diffusion Decomposition
• Precipitates
• Ostwald Ripening
• Real Crystals
• Macrodefects
• Grain Boundaries
• Grain Boundary Diffusion
• Ageing Metal Alloys
• Reactor Constructional Materials
• Radiation Strength
• Diffusion Growth
• Vacancy Pore