Abstract
The nucleation, growth and coarsening of carbides is investigated in high niobium containing TiAl alloys by diffraction and transmission electron microscopy. Higher carbon content increases the dissolution temperature of carbides. The solubility of carbon is much higher in a γ/#x03B1;2-phase alloy than in the γ phase alone. Hereby no significant influence of Nb on carbon solubility is found. Crystallographic defects as grain boundaries and dislocations promote carbide nucleation which results in a carbide precipitation sequence starting first at grain boundaries, then at dislocations and only later in the γ matrix away from crystallographic defects. The consumption of carbon by grain boundary carbides or neighboring #x03B1;2 grains also generates a precipitate free zone in γ grains near the grain boundary.
Similar content being viewed by others
References
B.P. Bewlay, M. Weimer, T. Kelly, A. Suzuki and P.R. Subramanian, MRS Online Proceedings Library 1516, 49 (2013)
T. Tetsui, Mater Sci Forum 561-565, 379 (2007).
H. Clemens and S. Mayer, Adv Eng Mater 15, 191 (2013).
B.D. Worth, J.W. Jones and J.E. Allison, Metall Mater Trans A 26, 2961 (1995).
R. Gerling, F.P. Schimansky, A. Stark, A. Bartels, H. Kestler, L. Cha, C. Scheu and H. Clemens, Intermetallics 16, 689 (2008).
F. Appel, M. Oehring and R. Wagner, Intermetallics 8, 1283 (2000).
C. Scheu, E. Stergar, M. Schober, L. Cha, H Clemens, A. Bartels, F.P. Schimansky and A. Cerezo, Acta Mater 57, 1501 (2009).
R. Gerling, H. Clemens and F.P. Schimansky, Adv Eng Mater 6, 23 (2004).
H. Gabrisch, A. Stark, F.P. Schimansky, L. Wang, N. Schell, U. Lorenz and F. Pyczak, Intermetallics 33, 44 (2013).
Z.C. Liu, J.P. Lin, S.J. Li and S.L. Chen, Intermetallics 10, 653 (2002).
S. Gebhard, F. Pyczak, M. Göken, Mater Sci Eng, A 523, 235 (2009).
F. Appel and R. Wagner, Mater Sci Eng R22, 187 (1998).
A. Menand, A. Huguet and A. Nérac-Partaix, Acta Mater 44, 4729 (1996).
Acknowledgements
Li Wang acknowledges the Chinese Scholarship Council (CSC) - Helmholtz Association program for funding her PhD project at the Helmholtz-Zentrum Geesthacht.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Wang, L., Pyczak, F., Gabrisch, H. et al. ffects of Carbon Content, Annealing Condition and Internal Defects on the nucleation, growth and coarsening of P-type Carbides in High Niobium Containing TiAl Alloys. MRS Online Proceedings Library 1760, 61–66 (2014). https://doi.org/10.1557/opl.2014.967
Published:
Issue Date:
DOI: https://doi.org/10.1557/opl.2014.967