Massive Transformation in High Niobium Containing TiAl-Alloys


Massive transformation in high Nb bearing γ-TiAl-based alloys, Ti-45Al-7.5Nb and Ti-46A1-9Nb (at.%), and the thermal stability of the resulting microstructure were investigated. Using a quenching dilatometer, a nearly complete massive transformation in Ti-45Al-7.5Nb was found at about 1050°C after annealing at 1305°C for 10min and subsequent cooling with a rate of 55K/s. Higher starting temperatures and higher cooling rates lead to incomplete massive transformation and small transformed areas situated at the grain-boundary triple points of the parent α-grains are observed. By means of EBSD only in one case the same orientation of the close-packed planes of parent α-grains and of massively transformed γM-areas was observed.

The thermal stability of the microstructure of massively transformed Ti-46Al-9Nb sheet material was tested by annealing samples for 1 hour between 400 and 1200°C. Above 800°C a drop of hardness was measured and X-ray diffraction patterns show an increasing separation of (200)γ and (002)γ reflections as expected from a tetragonal γ-TiAl lattice. After annealing at 1100°C α2-phase segregates at grain boundaries and after 1200°C α2-lamellae appear insides the γM-grains parallel to all four {111}γ-planes.

This is a preview of subscription content, access via your institution.


  1. 1.

    F. Appel, M. Oehring, R. Wagner, Intermetallics, 8, 1283 (2000)

    CAS  Article  Google Scholar 

  2. 2.

    W.J. Zhang, S.C. Deevi, G.L. Chen, Intermetallics, 10, 403 (2002)

    CAS  Article  Google Scholar 

  3. 3.

    F. Appel, Mat. Sci. Eng. A317, 115 (2001)

    CAS  Article  Google Scholar 

  4. 4.

    General Discussion Session of the Symposium on “The Mechanism of the Massive Transformation“, edited by H.I. Aaronson and V.K. Vasudevan, Metall. Mater. Trans., 33A, 2445 (2002)

    Google Scholar 

  5. 5.

    D. Hu, in Ti-2003, edited by G. Lütjering and J. Albrecht (Wiley-VCH Verlag, Weinheim, Germany, 2004) p. 2369

  6. 6.

    R. Gerling, H. Clemens, F.-P. Schimansky, Advanced Engineering Materials 6, 23 (2004)

    CAS  Article  Google Scholar 

  7. 7.

    R. Gerling, A. Bartels, H. Clemens, H. Kestler, F.-P. Schimansky, Intermetallics 12, 275 (2004)

    CAS  Article  Google Scholar 

Download references

Author information



Corresponding author

Correspondence to A. Bartels.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Bartels, A., Bystrzanowski, S., Chladil, H. et al. Massive Transformation in High Niobium Containing TiAl-Alloys. MRS Online Proceedings Library 842, 31–36 (2004).

Download citation