Metallurgical and Materials Transactions A

, Volume 34, Issue 10, pp 2377–2386 | Cite as

Microstructure evolution during alpha-beta heat treatment of Ti-6Al-4V

  • S. L. Semiatin
  • S. L. Knisley
  • P. N. Fagin
  • D. R. Barker
  • F. Zhang


A framework for the prediction and control of microstructure evolution during heat treatment of wrought alpha/beta titanium alloys in the two-phase field was established via carefully controlled induction heating trials on Ti-6Al-4V and accompanying mathematical modeling based on diffusion-controlled growth. Induction heat treatment consisted of heating to and soaking at a peak temperature T p=955 °C, controlled cooling at a fixed rate of 11 °C/min, 42 °C/min, or 194 °C/min to a variety of temperatures, and final water quenching. Post-heat-treatment metallography and quantitative image analysis were used to determine the volume fraction of primary (globular) alpha and the nucleation sites/growth behavior of the secondary (platelet) alpha formed during cooling. The growth of the primary alpha during cooling was modeled using an exact solution of the diffusion equation which incorporated diffusion coefficients with a thermodynamic correction for the specific composition of the program material and which took into account the large supersaturations that developed during the heat-treatment process. Agreement between measurements and model predictions was excellent. The model was also used to establish a criterion for describing the initiation and growth of secondary alpha as a function of supersaturation, diffusivity, and cooling rate. The efficacy of the modeling approach was validated by additional heat treatment trials using a peak temperature of 982 °C.


Material Transaction Titanium Alloy Supersaturation Continuous Cool Beta Phase 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    S.L. Semiatin: in Advances in the Science and Technology of Titanium Alloy Processing, I. Weiss, R. Srinivasan, P.J. Bania, D. Eylon, and S.L. Semiatin, eds., TMS, Warrendale, PA, 1997, pp. 3–73.Google Scholar
  2. 2.
    G.W. Kuhlman: in Microstructure/Property Relationships in Titanium Aluminides and Alloys, Y-W. Kim and R.R. Boyer, eds., TMS, Warrendale, PA, 1991, pp. 465–91.Google Scholar
  3. 3.
    R.D. Doherty: in Physical Metallurgy, R.W. Cahn and P. Haasen, eds., North-Holland, Amsterdam, 1996, ch. 15.Google Scholar
  4. 4.
    O. Grong and H.R. Shercliff: Progr. Mater. Sci., 2002, vol. 47, pp. 163–282.CrossRefGoogle Scholar
  5. 5.
    P.G. Shewmon: Diffusion in Solids, McGraw-Hill Book Company, New York, NY, 1963.Google Scholar
  6. 6.
    H.S. Carslaw and J.C. Jaeger: Conduction of Heat in Solids, Oxford University Press, London, 1959.Google Scholar
  7. 7.
    J. Crank: Mathematics of Diffusion, Oxford University Press, London, 1956.Google Scholar
  8. 8.
    W.W. Mullins and R.F. Sekerka: J. Appl. Phys., 1963, vol. 34, pp. 323–29.CrossRefGoogle Scholar
  9. 9.
    R. Trivedi: Metall. Trans., 1970, vol. 1, pp. pp. 921–27.Google Scholar
  10. 10.
    W.P. Bosze and R. Trivedi: Metall. Trans., 1974, vol. 5, pp. 511–12.Google Scholar
  11. 11.
    S. Malinov, P. Markovsky, W. Sha, and Z. Guo: J. Alloys Componds, 2001, vol. 314, pp. 181–92.CrossRefGoogle Scholar
  12. 12.
    F.J. Gil, M.P. Ginebra, J.M. Manero, and J.A. Planell: J. Alloys Compounds, 2001, vol. 329, pp. 142–52.CrossRefGoogle Scholar
  13. 13.
    H.B. Aaron, D. Fainstein, and G.R. Kotler: J. Appl. Phys., 1970, vol. 41, pp. 4404–10.CrossRefGoogle Scholar
  14. 14.
    U. Zwicker: Titanium and Titanium Alloys, Springer-Verlag, Berlin, 1974.Google Scholar
  15. 15.
    H. Araki, T. Yamane, Y. Minamino, S. Saji, Y. Hana, and S.B. Jung: Metall. Mater. Trans. A, 1994, vol. 25A, pp. 874–76.Google Scholar
  16. 16.
    L.S. Darken and R.W. Gurry: Physical Chemistry of Metals, McGraw-Hill Book Company, New York, NY, 1953.Google Scholar
  17. 17.
    D.A. Porter and K.E. Easterling: Phase Transformations in Metals and Alloys, Chapman & Hall, London, 1992.Google Scholar
  18. 18.
    S.L. Semiatin and T.R. Bieler: Acta Mater., 2001, vol. 49, pp. 3565–73.CrossRefGoogle Scholar

Copyright information

© ASM International & TMS-The Minerals, Metals and Materials Society 2003

Authors and Affiliations

  • S. L. Semiatin
    • 1
  • S. L. Knisley
    • 2
  • P. N. Fagin
    • 3
  • D. R. Barker
    • 3
  • F. Zhang
    • 4
  1. 1.the Air Force Research Laboratory, Materials and Manufacturing DirectorateAFRL/MLLMWright-Patterson Air Force Base
  2. 2.the Chemical Engineering DepartmentUniversity of DaytonDayton
  3. 3.UES, Inc.Dayton
  4. 4.Compu Therm LLCMadison

Personalised recommendations