ICAMS / Interdisciplinary Centre for Advanced Materials Simulation

Research Highlights

Inverse ripening and rearrangement of precipitates under chemomechanical coupling

R. Darvishi Kamachali, C. Schwarze.

A coupling between diffusional and mechanical relaxation raised from composition-dependent elastic constants, and its effects on the evolution of precipitates with finite misfit strain are investigated. Inverse ripening has been observed where smaller precipitate grows at the expense of a larger one. This occurs due to fluxes generated under elastically-strained solute gradients around precipitates that scales with (R/r)^6 where R and r are the precipitate radius and the radial coordinate, respectively. Both isotropic and anisotropic dependency of elastic constants on the composition were considered. The latter leads to the emergence of new patterns of elastic anisotropy and rearrangement of precipitates in the matrix.

In the presence of chemomechanical coupling effect, inverse ripening occurs in which the smaller precipitate grows at the expense of the larger one. The size evolution and configuration of two evolving precipitates are shown in the Figure. The precipitates have different initial size.