|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Phase Transformations and Microstructural Evolution
||Hydrostatic Compression Behavior and High-pressure Stabilized b-phase in g-based Titanium Aluminide Intermetallics
||Klaus-Dieter Liss, Xi Li, Ken-Ichi Funakoshi, Rian Johannes Dippenaar, Yuji Higo, Ayumi Shiro, Mark Reid, Hiroshi Suzuki, Takahisa Shobu, Koichi Akita
|On-Site Speaker (Planned)
Titanium-aluminides find application in modern light-weight, high-temperature aircraft engines, but suffer from poor plasticity during manufacturing and processing. Here we report on an in-situ synchrotron X-ray diffraction study in a large-volume-press of a modern (α2 + γ) material, Ti-45Al-7.5Nb-0.25C, under pressures and temperatures up to 9.6 GPa and 1686 K. At room temperature, the volume response to pressure is accommodated by the transformation γ → α2, expressed by apparently high bulk moduli of both constituent phases. Lattice strain and atomic order are discussed in detail. It is interesting to note that this transformation takes place despite an increase in atomic volume. Upon heating under high pressure, both the eutectoid and γ-solvus transition temperatures are elevated, and a third, cubic β-phase is stabilized above 1350 K. Earlier research has shown that this β-phase is very ductile, essential in near-conventional forging processes. Novel processing routes can be defined from these findings.
||Planned: Supplemental Proceedings volume