Analysis of the Solidification Microstructure of Multi- Component γ-TiAl Alloys

Abstract:

Gamma titanium aluminide alloys often solidify peritectically and show a coarse, dendritic microstructure, which can lead to unacceptable mechanical properties in the as-cast condition. In view of the development of improved cast alloys, the dependence of the solidifying microstructure on the aluminum content and other alloying elements was investigated. The formation of the observed solidification microstructures is discussed in comparison with microstructure formation maps calculated by the NCU (nucleation and constitutional undercooling) model developed by Hunziker et al. [1].

• Periodical: Materials Science Forum (Volumes 539-543)
• Pages: 1475-1480
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.539-543.1475
• Online since: March 2007
• Authors: Michael Oehring, V. Küstner, Fritz Appel, Uwe Lorenz
• Keywords: Gamma TiAl Alloys, Microstructure Selection Map, Solidification

References

[1] O. Hunziker, M. Vandyoussefi, W. Kurz: Acta mater. Vol. 46 (1998), pp.6325-6336.

[2] Y-W. Kim, D. M Dimiduk, in: Structural Intermetallics 1997 (Eds. M.V. Nathal, R. Darolia, C.T. Liu, P.L. Martin, D.B. Miracle, R. Wagner, M. Yamaguchi, TMS, Warrendale, PA, 1997), pp.531-543.

[3] F. Appel, R. Wagner: Mater. Sci. Eng. R Vol. R22 (1998), pp.187-268.

[4] M. Yamaguchi, H. Inui, K. Ito: Acta mater. Vol. 48 (2000), pp.307-322.

[5] C.M. Austin, T.J. Kelly, in: Gamma Titanium Aluminides (Eds. Y-W. Kim, R. Wagner, M. Yamaguchi, TMS, Warrendale, PA, 1995), pp.21-32.

[6] S. Naka, M. Thomas, C. Sanchez, T. Khan, in: Structural Intermetallics 1997 (Eds. M.V. Nathal, R. Darolia, C.T. Liu, P.L. Martin, D.B. Miracle, R. Wagner, M. Yamaguchi, TMS, Warrendale, PA, 1997), pp.313-322.

[7] M. DeGraef, N. Biery, L. Rishel, T.M. Pollock, A. Cramb, in: Gamma Titanium Aluminides 1999 (Eds. Y-W. Kim, D.M. Dimiduk, M.H. Loretto, TMS, Warrendale, PA, 1999), pp.247-254.

[8] I. Ohnuma. Y. Fujita, H. Mitsui, K. Ishikawa, R. Kainuma, K. Ishida: Acta mater. Vol. 48 (2000), pp.3113-3123.

DOI: 10.1016/s1359-6454(00)00118-x

[9] C. McCullough, J.J. Valencia, C.G. Levi, R. Mehrabian: Acta metall. Vol. 37 (1989). p.13211336.

[10] H. -G. Brokmeier, M. Oehring, U. Lorenz, H. Clemens, F. Appel: Metall. Mater. Trans. A Vol. 35A (2004), pp.3562-3579.

[11] D. E Larsen, in: Intermetallic Matrix Composites (Eds. D.L. Anton, R. McMeeking, D. Miracle, P. Martin, Mater. Res. Soc. Symp. Proc. Vol. 194, MRS, Pittsburgh, PA, 1990), pp.285-292.

[12] T.T. Cheng, in: Gamma Titanium Aluminides 1999 (Eds. Y-W. Kim, D.M. Dimiduk, M.H. Loretto, TMS, Warrendale, PA, 1999), pp.389-396.

[13] D.R. Johnson, K. Chihara, H. Inui, M. Yamaguchi: Acta mater. Vol. 46 (1998), pp.6529-6540.

[14] Y. Liu, G. Yang, Y. Zhou: J. Cryst. Growth Vol. 240 (2002), pp.603-610.

[15] B. Chalmers: Principles of Solidification (John Wiley and Sons, New York, NY, 1964).