Thermodynamic Calculation of Alpha-Case Formation in Titanium Alloys


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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




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