Modeling of shrinkage defects during solidification of long and short freezing materials

• Type: Article in International Scientific Journal
• Date: 2007

Authors

Ana Reis (Author) FEUP; Yvan Houbaert (Author) Other; Zhian Xu (Author) Other; Rob Van Tol (Author) Other; J. F. Duarte (Author) FEUP; A. D. Santos (Author) FEUP; A. Barbedo (Author) FEUP

Journal

Title: Journal of Materials Processing Technology

Vol. 202 No. 1

Pages: 428-434

ISSN: 0924-0136

Publisher: Elsevier

Indexing

Scopus

Scientific classification

FOS: Engineering and technology > Other engineering and technologies

CORDIS: Technological sciences > Engineering > Simulation engineering

Other information

Abstract (EN): The aim of the model presented in this paper is to capture the difference in solidification behavior of long and short freezing materials. The shrinkage defects in short freezing materials tends to be internal, as porosity, while in long freezing materials these defects tend to be external in the form of surface depressions. To achieve this, a pressure drop based 3D feeding flow model has been developed to evaluate shrinkage defects for casting alloys. A continuum formulation is used to describe the transport of mass, energy and momentum. It is assumed that during solidification the driving force for flow is shrinkage. A Darcy type source term has been included in the momentum equation to account for flow resistance in the mushy zone. A VOF free surface model has been used to describe shrinkage defects, i.e., external surface depressions and internal shrinkage porosities, while ensuring mass conservation. The model is used to calculate the shrinkage in a simple casting. The results shows internal and outside shrinkage defects depending on the freezing range of the metal. Short freezing range results mainly in internal shrinkage whereas the long freezing range results in external shrinkage. The expected shrinkage features are well described by the present model.

Language: Portuguese

Type (Professor's evaluation): Scientific