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The European Physical Journal Special Topics

, Volume 223, Issue 3, pp 559–565 | Cite as

The free growth criterion for grain initiation in TiB 2 inoculated γ-titanium aluminide based alloys

  • D. GosslarEmail author
  • R. Günther
Regular Article
Part of the following topical collections:
  1. Heterogenous Nucleation and Microstructure Formation: Steps Towards a System and Scale Bridging Understanding

Abstract

γ-titanium aluminide (γ-TiAl) based alloys enable for the design of light-weight and high-temperature resistant engine components. This work centers on a numerical study of the condition for grain initiation during solidification of TiB2 inoculated γ-TiAl based alloys. Grain initiation is treated according to the so-called free growth criterion. This means that the free growth barrier for grain initiation is determined by the maximum interfacial mean curvature between a nucleus and the melt. The strategy presented in this paper relies on iteratively increasing the volume of a nucleus, which partially wets a hexagonal TiB2 crystal, minimizing the interfacial energy and calculating the corresponding interfacial curvature. The hereby obtained maximum curvature yields a scaling relation between the size of TiB2 crystals and the free growth barrier. Comparison to a prototypical TiB2 crystal in an as cast γ-TiAl based alloy allowed then to predict the free growth barrier prevailing under experimental conditions. The validity of the free growth criterion is discussed by an interfacial energy criterion.

Keywords

European Physical Journal Special Topic Maximum Curvature Crystal Face Free Growth Titanium Boride 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. 1.
    F. Appel, J.D.H. Paul, M. Oehring, Gamma Titanium Aluminide Alloys (Wiley VCH, Weinheim, 2011)Google Scholar
  2. 2.
    Y.W. Kim, Intermetall. 6, 623 (1998)CrossRefGoogle Scholar
  3. 3.
    U. Hecht, A. Witusiewicz, A. Drevermann, J. Zollinger, Intermetallics 16, 969 (2008)CrossRefGoogle Scholar
  4. 4.
    D. Gosslar, R. Günther, U. Hecht, C. Hartig, R. Bormann, Acta Mater. 58, 6744 (2010)CrossRefGoogle Scholar
  5. 5.
    A.L. Greer, A.M. Bunn, A. Tronche, P.V. Evans, D.J. Bristow, Acta Mater. 48, 2823 (2000)CrossRefGoogle Scholar
  6. 6.
    M. Apel, J. Eiken, U. Hecht, Eur. Phys. J. Special Topics 223(3), 545 (2014)ADSGoogle Scholar
  7. 7.
    D. Gosslar, C. Hartig, R. Günther, U. Hecht, R. Bormann, J. Phys.: Condens. Matter 58, 1 (2009)Google Scholar
  8. 8.
    M. Hyman, C. McCullough, C. Levi, R. Mehrabian, Metall. Mater. Trans. A 22, 1647 (1991)ADSCrossRefGoogle Scholar
  9. 9.
    K. Brakke, Exper. Math. 1, 141 (1992)CrossRefzbMATHMathSciNetGoogle Scholar
  10. 10.
    S.A. Reavley, A.L. Greer, Phil. Mag. 88, 516 (2008)CrossRefGoogle Scholar
  11. 11.
    A.A. Abdel-Hamid, S. Hamar-Thibault, R. Hamar, J. Cryst. Growth 71, 744 (1985)ADSCrossRefGoogle Scholar

Copyright information

© EDP Sciences and Springer 2014

Authors and Affiliations

  1. 1.Institute of Materials Physics and Materials Technology, Hamburg University of TechnologyHamburgGermany

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