Thermodynamic Calculation of Alpha-Case Formation in Titanium Alloys


Article Preview

The alpha-case formation mechanism was elucidated for the economic titanium casting. The α-case formation reaction between Ti and Al2O3 mold was examined in a plasma arc melting furnace. The reaction products were characterized by electron probe micro-analyzer and transmission electron microscopy. The α-case generation between Ti and Al2O3 mold was not able to be explained by the conventional α-case formation mechanism, which is known to be formed by the interstitials, especially oxygen dissolved from mold materials. However, from our experimental results and thermodynamic calculations and Calphad modeling (Thermo-calc®), it was confirmed that the α-case is formed not only by an interstitial element but also by substitutional metallic elements dissolved from mold materials. Our newly established α-case formation mechanism will surely lead to a variety of significant applications of the α-case controlled Ti casting.



Advanced Materials Research (Volumes 26-28)

Edited by:

Young Won Chang, Nack J. Kim and Chong Soo Lee




S. Y. Sung et al., "Thermodynamic Calculation of Alpha-Case Formation in Titanium Alloys", Advanced Materials Research, Vols. 26-28, pp. 519-522, 2007

Online since:

October 2007




[1] C. Leyens and M. Peters : Titanium and Titanium alloys (Wiley-VCH, Germany 2003).

[2] H. Clemens and H. Kestler : Adv. Eng. Mater. Vol. 2 (2000), p.551.

[3] F.H. Fores et al : Cost-Affordable Titanium (TMS, USA 2004).

[4] D. B. Williams and C. B. Carter : Transmission Electron Microscopy-A textbook for Materials science (Plenum Press, New York, 1996).

[5] M. W. Chase, C. A. Davies, J. R. Downey, D. J. Frurip, R .A. McDonald and A. N. Syverud : JANAF Thermochemical Tables (American Chemical Society and American Institute of Physics 1985).

[6] Information on http: /www. thermocalc. com (TCW4 Calphad software, Thermo-calc® ).

Fetching data from Crossref.
This may take some time to load.