To main content

Numerical study of the impact of inoculant and grain transport on macrosegregation and microstructure formation during solidification of an Al-22%Cu alloy

Abstract

We investigate the impact of the nucleation law for nucleation on Al-Ti-B inoculant particles, of the motion of inoculant particles and of the motion of grains on the predicted macrosegregation and microstructure in a grain-refined Al-22 wt.% Cu alloy casting. We conduct the study by numerical simulations of a casting experiment in a side-cooled 76×76×254 mm sand mould. Macrosegregation and microstructure formation are studied with a volume-averaged two-phase model accounting for macroscopic heat and solute transport, melt convection, and transport of inoculant particles and equiaxed grains. On the microscopic scale it accounts for nucleation on inoculant particles with a given size distribution (and corresponding activation undercooling distribution)and for the growth of globular solid grains. The growth kinetics is described by accounting for limited solute diffusion in both liquid and solid phases and for convective effects. We show that the consideration of a size distribution of the inoculants has a strong impact on the microstructure(final grain size) prediction. The transport of inoculants significantly increases the microstructure heterogeneities and the grain motion refines the microstructure and reduces the microstructure heterogeneities.

Category

Academic article

Language

English

Author(s)

  • Knut Omdal Tveito
  • M Bedel
  • M Zaloznik
  • Herve Combeau
  • Mohammed Mhamdi
  • Ashwini Kumar
  • P Dutta

Affiliation

  • Norwegian University of Science and Technology
  • Université de Lorraine
  • SINTEF Industry / Metal Production and Processing
  • Indian Institute of Science

Year

2012

Published in

IOP Conference Series: Earth and Environmental Science (EES)

ISSN

1755-1307

Publisher

IOP Publishing

Volume

33

View this publication at Cristin