Computer Simulation Of Multiple Length-Scale Solidfication Transport Behaviors Associated With Thermo-Calc Software

Blades are key component parts in various areo-engines and the gas turbines. They are usually made by the method of directional solidification. In the directional solidification processes, there are exist three basic transport phenomena, i.e. heat transfer, solute mass transfer and momentum transfer, which are closely coupled and exert an important affect on the solidification behaviors. So numerically simulating the solidification transport phenomena is helpful to understand the solidification process, based on which we can make optimized techniques to get high quality blades.In this thesis, using a continuum model for solidification transfer phenomena (STP, i.e. refer to the heat transfer, solute mass transfer and fluid flow momentum transfer in the solidification processes), and based on the independently developed computer codes for numerical simulation of directional solidification transfer phenomena and a commercial software of Thermo-Calc, the following work were carried out in the present thesis:Based on the continuum model for solidification transfer phenomena, the codes for numerical simulation of directional solidification of blade like castings are revised. And the closely coupling of the codes for numerical simulation with the Thermo-Calc software is successfully realized.Using the thermo-Calc software of TCCR/TCW4/TQ6 version, the solidification paths and phase diagrams of Ga-In-Sn, Al-Cu-Fe-Si and Ti-Al-Si multiconpomnent systems are caculated. The computational results are instructive to the related experiments.Based on the codes previously developed by the author's workgroup for numerical simulation of directional solidification, blade-like castings of Al-Cu% and Fe-C% alloys are simulated, in which the composition-dependent liquidus temperatures and partition coefficients in the solidification processes are determined via calling the interface program of TQ6 and the related databases.The coupled computational results indicate that the STP-based application program and the thermo-calc software had been integrated together successfully. The present work makes a basis for the future researches on development of STP- based modeling and the computer codes for multiconpomnent solidification systems.