Numerical modeling of hot tearing formation in metal casting and its validations

Abstract

AbstractHot tearing is one of the most serious defects for a metal casting. The nucleation and propagation of the hot tearing can result in permanent defects in the casting, which may cause the final cast product to be unusable. It is believed that the imposed strains and stresses on the solid framework in the mushy zone by the solidification shrinkage and thermal contraction create the conditions for hot tearing. It has been very well documented that the composition of the alloy and the mechanical properties of the metals in the semi‐solid state play critical roles in the formation of hot tears. To predict the susceptibility of hot tearing in a casting, a hot tearing indictor is proposed which is based on Gurson's constitutive model and uses the thermophysical and thermomechanical properties obtained from a thermodynamic calculation in the final stage of solidification. The numerical implementation of the hot tearing indicator is described in detail and the numerical modeling of the hot tearing formation is validated by experiments. Copyright © 2010 John Wiley & Sons, Ltd.