The influence of applied stress on precipitate shape and stability

Shape transitions and orientation alignment of elastically misfitting precipitates in the presence of an external stress field have been predicted using bifurcation and group theory and by performing actual energy calculations for elliptical cylinders under plane strain conditions. Under the assumption of system isotropy, the applied field acts to break or perturb the bifurcation. Both first- and second-order size-induced shape transitions are observed for elastically soft precipitates. Stress-induced shape transitions are shown to be either first- order or continuous for elastically soft precipitates. Only continuous stress-induced shape transitions are observed for hard precipitates.