Modeling of Columnar-to-Equiaxed Transition in Solidified Al-Si Alloys

摘要

A Cellular-Automaton Finite-Volume-Method (CAFVM) algorithm has been developed, coupling with macroscopic model for heat transfer calculation AND MICROSCOPIC MODELS for nucleation and growth. The solution equations have been solved to determine the time dependent constiutional undercooling and interface retardation during solidification. The constitutional undercooling is then coupled into the CAFVM algorithm to investigate both the effects of thermal and constitutional undercooling on columnar glgorithm to investigate both the columnar zone, and formation of equiaxed crystals in the bulk liquid. The model cannot only simulate microstructures of alloys but also investigates nucleate mechanisms and growth kinetics of alloys solidified with various solute concentrations and solidification morphologies.