Presented in

AFS Transactions '95

Page 243

Thermal Transport Phenomena in Metalcasting Simulations

H. Huang

O. Gurdogan

H.U. Akay

Technalysis Incorporated
Indianapolis, Indiana

W.W. Fincher

Lufkin Industries, Inc.
Lufkin, Texas

Abstract

An interface element model has been developed for a finite element method-based casting filling/solidification simulation software. The thermal resistance at the casting-mold interface is treated through an interface element with zero thickness and coincident nodes. The principle of this model is described. The model is tested through an example of practical size. The computed results of the interface element model are compared with the experimental data, as well as the computed results of the conventional effective heat transfer coefficient model and common node model.

A heat source/sink algorithm has also been incorporated into the solidification solver. The algorithm combines the concept of the temperature recovery method and heat source/sink term in the thermal energy equation. The advantage of this algorithm, over the effective specific heat method, is that the phase transformation will not be complete until all the heat of transformation has been released or absorbed.

Introduction

Heat transfer across the casting-mold interface plays an important role in the heat removal from the molten metal and, hence, the filling and solidification of a casting. It has been recognized that a fast rate of heat removal from the molten metal helps to obtain better microstructures and reduce undesirable pores in a casting. On the other hand, a slow rate of heat removal may result in coarse microstructures and allow undesirable pores to develop. Generally speaking, most thermal energy in molten metal is removed through the casting-mold interface. Hence, the heat transfer across the casting-mold interface has received considerable attention from metalcasting researchers.