Elastic effects associated with the formation of precipitates in a free thin layer: Part II. Interaction energies in thin layers

This second part of the paper is concerned with the contribution of the elastic energy to the evolution of the microstructure in elastically homogenous free thin layers, in which dilating precipitates are formed. The elastic interaction between dilating precipitates is attractive at small interprecipitate separations, decays steeply with increasing interparticle distance and becomes repulsive at large interparticle separations. Such an interaction gives rise to spatial correlation between precipitates and clustering of equisized precipitates is predicted. The attractive interaction between precipitates and the free surfaces increases as the precipitates grow and is larger than the interparticle interaction. Hence, elastic energy considerations favor the appearance and possible coalescence of precipitates in thin 61ms, at an advanced stage of the growth. The elastic relaxation of non-spherical precipitates is enhanced when their long axes are lying parallel to the free surfaces. For such configurations, the self-energy and range of interprecipitate elastic interaction decrease.