NUMERICAL DETERMINATION OF SECONDARY ARM SPACING OF Fe-C AS A FUNCTION OF COOLING RATE AND LOCAL SOLIDIIFCATION TIME

摘要

The phase-field model is widely used as one of the powerful computational methods to simulate the formation of complex microstructures. In this present study, the secondary arm spacing for Fe-C binary alloys are numerically predicted using a phase-field model in the two-dimensional domain. The predicted arm spacing from the present work compared with both the data by Ode et al, and the experimental data showed an excellent agreement. It is estimated at the late stage of growth. The change in the arm spacing is examined by the both changes of cooling rates and local solidification time. The relation between material properties and model parameters is presented. Two-dimensional simulations produced dendrites, which are similar to the ones found in experiments reported in the literature. Through the numerical examples, the applicability of the phase-field model to the problems of secondary dendrite arm spacing of the Fe-C alloys is demonstrated.