On Microstrucitural Evolution in Gas Atomized Ti-50 at.% Al-2 at.% Nb Powder


Microstructural development in helium gas atomized Ti-50A1-2Nb (at.%) powder has been characterized using x-ray diffractometry and transmission electron microscopy. The structure of the as-atomized powder was a mixture of two phases: an ordered fct (L10)γ TiAl phase and an hcp α Ti phase containing fine (≈ 10–20 nm) D019 α2 domains. Large powder (≈ 250 μm) contained ≈ 14 volume % hcp phase, while fine powder (≈37 μm) contained ≈ 72 volume % hcp phase. However, this α+α2 constituent was metastable and transformed to the γ phase during annealing.

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


  1. 1.

    D. Shechtman, M.J. Blackburn and H.A. Lipsitt, Metall. Trans. 5, 1373 (1974).

    CAS  Article  Google Scholar 

  2. 2.

    C.C. Koch, Mat. Res. Soc. Symp. Proc. 39, 397 (1985).

    CAS  Article  Google Scholar 

  3. 3.

    J.A. Graves, J.H. Perepezko, C.H. Ward and F.H. Froes, Scripta Metall. 21, 567 (1987).

    CAS  Article  Google Scholar 

  4. 4.

    J.A. Graves, L.A. Bendersky, F.S. Biancaniello, J.H. Perepezko and W.J. Boettinger, Proc. Rapid Quench-6, Montreal, Canada, August (1987).

  5. 5.

    J.J. Valencia, C. McCullough, C.G. Levi and R. Mehrabian, Scripta Metall. 21, 1341 (1987).

    CAS  Article  Google Scholar 

  6. 6.

    R.D. Field and H.L. Fraser, Metall. Trans. 9A, 131 (1978).

    CAS  Article  Google Scholar 

  7. 7.

    R. Wheeler, University of Illinois-Urbana, Champaign, (private communication).

  8. 8.

    P. Duwez and J.L. Taylor, Trans. AIME. 194, 70 (1952).

    Google Scholar 

  9. 9.

    A.J. Goldak and J.G. Parr, Trans. Met. Soc. AIME. 221, 639 (1961).

    CAS  Google Scholar 

  10. 10.

    W. Rostoker, Trans. AIME. 194, 212 (1952).

    Google Scholar 

  11. 11.

    D. Clark, K.S. Jepson and G.I. Lewis, JIM. 91, 197 (1062).

    Google Scholar 

  12. 12.

    B. Chalmers, Principles of Solidification. (John Wiley & Sons, New York, 1964), p 117.

  13. 13.

    C. McCullough, J.J. Valencia, H. Mateos, C.G. Levi, R. Mehrabian and K.A. Rhyne, Scripta Metall. 22, 1131(1988).

    CAS  Article  Google Scholar 

  14. 14.

    S.C. Huang and P.A. Siemers, (submitted to Metall. Trans.).

Download references

Author information



Corresponding author

Correspondence to Donald S. Shih.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Shih, D.S., Scarr, G.K. & Chesnutt, J.C. On Microstrucitural Evolution in Gas Atomized Ti-50 at.% Al-2 at.% Nb Powder. MRS Online Proceedings Library 133, 167 (1988). https://doi.org/10.1557/PROC-133-167

Download citation