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Modeling of grain refinement: Part II. Effect of nucleant particles—TiB2 additions for aluminum

Published online by Cambridge University Press:  31 January 2011

X. Yao*
Affiliation:
School of Engineering, University of Queensland, Brisbane, 4072 QLD, Australia
S.D. McDonald
Affiliation:
CRC Centre for Metals Manufacturing (CAST) Cooperative Research Centre, University of Queensland, Brisbane, 4072 QLD, Australia
A.K. Dahle
Affiliation:
CRC Centre for Metals Manufacturing (CAST) Cooperative Research Centre, University of Queensland, Brisbane, 4072 QLD, Australia
C.J. Davidson
Affiliation:
Commonwealth Scientific and Industrial Research Organization (CSIRO)—Manufacturing & Infrastructure Technology, Kenmore, 4069 QLD, Australia
D.H. StJohn
Affiliation:
CRC Centre for Metals Manufacturing (CAST) Cooperative Research Centre, University of Queensland, Brisbane, 4072 QLD, Australia
*
a)Address all correspondence to this author. e-mail: x.yao@uq.edu.au
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Abstract

Following the discussion of modeling grain refinement in Part I, [X. Yao, et al., J. Mater. Res.23(5), 1282, the effect of Al–Ti–B master alloy additions on grain formation in commercial-purity (CP) aluminum was investigated. The characteristics of the addition particles as applicable to the model are presented. The effect of adding TiB2 particles, the introduction of extra particles by reactions in the melt, and the effect of adding extra solute Ti are all modeled. The distribution of the potential particles and its effect on grain formation was also modeled to establish the relationship between the grain size and microstructure morphology and the additive characteristics. The calculated results are comparable with experimental data. Accordingly, possible mechanisms of grain refinement with Al–Ti–B refiners were proposed.

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Articles
Copyright
Copyright © Materials Research Society 2008

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References

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