Paper Title:
Macroscopic Model for Predicting Columnar to Equiaxed Transitions Using Columnar Front Tracking and Average Equiaxed Growth
  Abstract

A macroscopic model of Columnar-to-Equiaxed Transition (CET) formation is presented. The growth of a columnar zone and an equiaxed zone are treated separately and modeled on a fixed grid. The model uses a columnar Front Tracking (FT) formulation to compute the motion of the columnar front and the solidification of the dendritic columnar mushy zone. The model for the equiaxed zone calculates the average growth of equiaxed grains within the control volumes of undercooled liquid. The proposed model, which calculates the average equiaxed growth, is different from previous FT models which consider each equiaxed grain envelope separately. A lognormal size distribution model of seed particles is used for the equiaxed nucleation in the undercooled liquid zone. After nucleation, average equiaxed growth is computed by considering the equiaxed envelopes as spherical. The extended volume concept is used to deal with grain impingement. The Scheil equation is used to calculate the solid fraction and latent heat release. When the equiaxed fraction is great enough, advancement of the columnar front is halted and the CET position is determined. CET formation was simulated for directional solidification of an aluminium-silicon alloy. The results were compared with a previous FT-CET prediction model as well as with experimental data. Agreement was found in both cases.

  Info
Periodical
Edited by
A. Roósz, V. Mertinger, P. Barkóczy and Cs. Hoó
Pages
355-360
DOI
10.4028/www.scientific.net/MSF.649.355
Citation
W. Mirihanage, S. McFadden, D. J. Browne, "Macroscopic Model for Predicting Columnar to Equiaxed Transitions Using Columnar Front Tracking and Average Equiaxed Growth", Materials Science Forum, Vol. 649, pp. 355-360, 2010
Online since
May 2010
Export
Price
$32.00
Share

In order to see related information, you need to Login.

In order to see related information, you need to Login.

Authors: X. Yao, H. Wang, B. He, X. Zhou
Abstract:A Cellular-Automaton Finite-Volume-Method (CAFVM) algorithm has been developed, coupling with macroscopic model for heat transfer...
3141
Authors: Charles-André Gandin, Bernard Billia, Gerhard Zimmermann, David J. Browne, M.D. Dupouy, G. Guillemot, Henri Nguyen-Thi, Nathalie Mangelinck-Noël, Guillaume Reinhart, Laszlo Sturz, Shaun McFadden, Jerzy Banaszek, Yves Fautrelle, K. Zaïdat, A. Ciobanas
Abstract:The main objective of the research project of the European Space Agency (ESA) - Microgravity Application Promotion (MAP) programme entitled...
393
Authors: H.J. Dai, H.B. Dong, H.V. Atkinson, Peter D. Lee
Abstract:A coupled cellular automaton-finite difference (CA-FD) model is used to simulate the detailed dendritic structure evolution of the...
129
Authors: Shaun McFadden, David J. Browne, Laszlo Sturz, Gerhard Zimmermann
Abstract:This paper studies the Columnar to Equiaxed Transition (CET) in an Al-7wt%Si binary alloy with and without Al-Ti-B grain refiner. A...
361
Authors: Gerhard Zimmermann, L. Sturz, B. Billia, N. Mangelinck-Noël, D.R. Liu, H. Nguyen Thi, N. Bergeon, C.A. Gandin, D.J. Browne, C. Beckermann, D. Tourret, A. Karma
Chapter 1: Effect of Microgravity
Abstract:This paper gives an overview of the experiments on-board the International Space Station (ISS) performed so far by the CETSOL team. Al-7 wt%...
12