Shape evolution of an initially circular precipitate growing by diffusion in an applied stress field

The diffusional growth of a precipitate transforming under applied stress is analyzed to determine the shape evolution of the precipitate. The analysis is based on linearizing the precipitate shape about a circle. Because of applied stresses, a circle is a stable shape only when the shear moduli of the precipitate and the surrounding matrix are identical. Otherwise, one finds a non-circular base shape that depends on the applied stress and the...