Effect of Alloying and Thermal Processing on Mechanical Properties of TiAl Alloys

Abstract:

Two γ-based TiAl alloys with 7 at.% of Nb, alloyed with 2 at.% Mo and 0.5 at.% C, were studied. A heat treatment leading to very fine lamellar microstructure was applied on both alloys. Microstructure after the heat treatment was described and mechanical properties including fatigue behaviour were measured. The as-received material alloyed with C possesses high strength and very limited ductility, especially at RT. After application of selected heat treatment it becomes even more brittle; therefore, this process could be considered as not appropriate for this alloy. On the contrary, in the case of Mo alloyed material, both strength and ductility are improved by the heat treatment at RT and usual working temperature (~750 °C). Presence of the β phase is responsible for this effect. The selected heat treatment thus can be an alternative for this alloy to other thermomechanical treatments as high temperature forging.

• Periodical: Solid State Phenomena (Volume 258)
• Pages: 501-505
• DOI: https://doi.org/10.4028/www.scientific.net/SSP.258.501
• Online since: December 2016
• Authors: Alice Chlupová*, Milan Heczko, Karel Obrtlík, Přemysl Beran, Tomáš Kruml
• Keywords: Fatigue, Heat Treatment, Lamellar Microstructure, Mechanical Properties, TiAl Alloys

References

[1] F. Appel, J.D.H. Paul, M. Oehring: Gamma Titanium Aluminide Alloys: Science and Technology (John Wiley & Sons, 2011).

DOI: 10.1002/9783527636204

[2] H. Clemens, S. Mayer: Advanced Engineering Materials 15 (2013), 191.

[3] M. Schloffer, B. Rashkova, T. Schöberl, E. Schwaighofer, Z. Zhang, H. Clemens, S. Mayer: Acta Mat. 64 (2014) 241.

DOI: 10.1016/j.actamat.2013.10.036

[4] E. Schwaighofer, H. Clemens, S. Mayer, J. Lindemann, J. Klose, W. Smarsly, V. Güther: Intermetallics 44 (2014), 128.

DOI: 10.1016/j.intermet.2013.09.010

[5] A. Chlupová, M. Heczko, K. Obrtlík, J. Polák, P. Roupcová, P. Beran, T. Kruml: Materials & Design 99 (2016), 284.

DOI: 10.1016/j.matdes.2016.03.079

[6] L. Cha, C. Scheu, H. Clemens, H.F. Chladil, G. Dehm, R. Gerling, A. Bartels : Intermetallics 16 (2008), 868.

DOI: 10.1016/j.intermet.2008.03.009

[7] P. Beran, M. Petrenec, M. Heczko, B. Smetana, M. Žaludová, M. Šmíd, T. Kruml, L. Keller: Intermetallics 54 (2014), 28.

DOI: 10.1016/j.intermet.2014.05.010

[8] Y. Mine, K. Takashima, P. Bowen: Mat. Sci. Eng. A 532 (2012), 13.