Adaptive phase field modeling of morphological instability and facet formation during directional solidification of SiGe alloys

• Adaptive phase field modeling in morphological evolution in a SiGe directional solidification.
• Good agreement with classical theories and experimental results using a proper thermal gradient.
• Simulated facet formation mechanism consistent with experiments.

An adaptive phase field model is used to study the morphological instability and the facet formation during a directional solidification of SiGe alloys. Using highly anisotropic surface free energy and cusp kinetic functions, as well as a proper temperature gradient, the simulated critical growth velocity for various alloy concentrations is in good agreement with classical theories and experimental observations. The simulated facet formation and kinetics are also consistent with the experiments as well.