Abstract:A binary continuum model for dendritic solidification transport phenomena and corresponding numerical algorithm for the strong nonlinear coupling of T−f_S−C_L were extended to multicomponent alloys solidified under condition of Biot£0.1. Based on the extended model/algorithm, a method considering heat transfer was proposed to predict the solidification paths and microsegregation of alloys solidified under the same condition. The new algorithm and method were closely coupled with the commercial Thermo-Calc package via its TQ6-interface codes for instantaneous determination of the related thermodynamic data at each calculation time step. The sample simulation performed on an Al−2Si−3Mg alloy system indicates the availability and reliability of the model/algorithm and the proposed method for predicting solidification paths and microsegregation. Computional and experimental investigations on an Al−5.17Cu−2.63Si ternary alloy were conducted, and a reasonable agreement between the computation and experiment was obtained.

Key words: thermo-calc; solidification transport; solidification paths; microsegregation