Hostname: page-component-586b7cd67f-t8hqh Total loading time: 0 Render date: 2024-11-28T12:42:22.500Z Has data issue: false hasContentIssue false
  • English
  • Français

Effects of Geometric Constraint on Phase Selection and Segregation in Cast TiAl

Published online by Cambridge University Press:  04 February 2011

Sailei Zhang ,
David R. Johnson  and
Matthew J.M. Krane
Sailei Zhang
Affiliation:
School of Materials Engineering, Purdue University, West Lafayette, IN 47906, U.S.A.
David R. Johnson
Affiliation:
School of Materials Engineering, Purdue University, West Lafayette, IN 47906, U.S.A.
Matthew J.M. Krane
Affiliation:
School of Materials Engineering, Purdue University, West Lafayette, IN 47906, U.S.A.
Get access

Abstract

Simulations of directional solidification of binary peritectic TiAl alloys through ceramic preforms consisting of narrow straight channels with spacings on the order of the dendritic tip radius were performed with a modified cellular automaton coupled to a finite volume calculation of solute diffusion. Depending upon the channel spacing, the microstructure may be refined after dendritic growth through the preform. As the channel width decreases, the lateral solute diffusion in the liquid is more constrained, changing the morphology of the primary phase from dendritic to cellular. In narrow channels, the liquid concentration gradient ahead of the solid/liquid interface decreases resulted in lower growth velocities and higher undercoolings. For hypo-peritectic TiAl alloys, growth conditions that lead to growth of β dendrites can result in α nucleation and growth in narrow channels due to the geometric constraint on solute diffusion.

Keywords

crystal growthmicrostructurealloy
Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 1295: Symposium N – Intermetallic-Based Alloys for Structural and Functional Applications , 2011 , mrsf10-1295-n05-14
Copyright
Copyright © Materials Research Society 2011

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. Shao, R., Krane, M. J M, and Trumble, K. P., Metall. Mater. Trans. 36A, 2461 (2005).Google Scholar
2. Shao, R., Trumble, K. P., and Krane, M. J. M. in Modeling of Casting, Welding and Advanced Solidification Processes XII, edited by: Cockcroft, S. L. and Maijer, D. M., (John Wiley & Sons, Inc., New York, 2009), p.503.Google Scholar
3. Raghavan, S., Johnson, D. R., and Krane, M. J. M. in Solidification Processes and Microstructures: A Symposium in Honor of Prof. W. Kurz, edited by: Rappaz, M., Beckermann, C., and Trivedi, R. (John Wiley & Sons, Inc., New York, 2004) p. 413.Google Scholar
4. Cummins, S. J., Francois, M. M. and Kothe, D. B., Computers and Structures 83, 425 (2005).Google Scholar
5. Trivedi, R., Metall. Mater. Trans. 26A, 1583 (1995).Google Scholar