Phase field model for strong anisotropy of kinetic and highly anisotropic interfacial energy
(1.College of Mechanical and Electrical Engineering, Hohai University, Changzhou 213022, China2.山西省太原市北方大学材料科学与工程学院3.Department of Science and Technology, China North Industries Group Corporation, Beijing 100083, China)
Abstract: A phase-field model was established for simulating pure materials, which was calculated effectively and taken into account the strong anisotropy of kinetic and highly anisotropic interfacial energy. The anisotropy (strong kinetic and highly interfacial energy) of various degrees was simulated with numerical calculation. During a variety of interfacial anisotropy coefficient, equilibrium crystal shape varies from smoothness to corner. There has a critical value during the course of the transformation. When the anisotropy coefficenct is lower than the critical value, the growth velocity v increases monotonically with the increase of it. Whereas the anisotropy coefficent is higher than the critical value, the growth velocity decreases with the increases of it. During a variety of degree of supercooling, the growth velocity is under control from thermal diffusion to kinetics. Under the control of thermal diffusion, the growth velocity increases with the increase of degree of supercooling and tip radius R decreases with the increase of temperature. Under the control of kinetics, with the increase of degree of supercooling both V and R, which can not fit the traditional microcosmic theory.
Key words: anisotropy; kinetics; interfacial energy; growth rate; supercooling degree