Phase transformations in high niobium and carbon containing alpha-TiAl based alloys

• Published in: Intermetallics Vol. 14; no. 10-11; pp. 1194 - 1198
• Main Authors: Chladil, H F, Clemens, H, Leitner, H, Bartels, A, Gerling, R, Schimansky, F-P, Kremmer, S
• Format: Journal Article
• Language: English
• Published: 01-10-2006
• ISSN: 0966-9795
• DOI: 10.1016/j.intermet.2005.11.016

Phase transformations and phase transition temperatures in Ti-5 at.%Al alloyed with different amounts of niobium and carbon were investigated. Scanning electron microscopy, electron back-scattered diffraction and differential scanning calorimetry were applied for the characterisation of the prevailing phases and phase transformations. Both, niobium and carbon display a tendency to increase the eutectoid temperature, with carbon showing the stronger effect. In contrast, the influence of niobium and carbon on the alpha-transus temperature is rather small. Thermodynamic equilibrium calculations were performed with the aid of the software ThermoCalc and MatCalc on the basis of a commercially available TiAl database. Partly, the calculated data show significant differences when compared to experimental results.