@misc{schwaighofer_hotworking_behavior_2014, 
author={Schwaighofer, E., Clemens, H., Lindemann, J., Stark, A., Mayer, S.},
title={Hot-working behavior of an advanced intermetallic multi-phase Gamma-TiAl based alloy},
year={2014},
howpublished = {journal article},
doi = {https://doi.org/10.1016/j.msea.2014.07.040},
abstract = {New high-performance engine concepts for aerospace and automotive application enforce the development of lightweight intermetallic γ-TiAl based alloys with increased high-temperature capability above 750 °C. Besides an increased creep resistance, the alloy system must exhibit sufficient hot-workability. However, the majority of current high-creep resistant γ-TiAl based alloys suffer from poor workability, whereby grain refinement and microstructure control during hot-working are key factors to ensure a final microstructure with sufficient ductility and tolerance against brittle failure below the brittle-to-ductile transition temperature. Therefore, a new and advanced β-solidifying γ-TiAl based alloy, a so-called TNM alloy with a composition of Ti–43Al–4Nb–1Mo–0.1B (at%) and minor additions of C and Si, is investigated by means of uniaxial compressive hot-deformation tests performed with a Gleeble 3500 simulator within a temperature range of 1150–1300 °C and a strain rate regime of 0.005–0.5 s−1 up to a true deformation of 0.9. The occurring mechanisms during hot-working were decoded by ensuing constitutive modeling of the flow curves by a novel phase field region-specific surface fitting approach via a hyperbolic-sine law as well as by evaluation through processing maps combined with microstructural post-analysis to determine a safe hot-working window of the refined TNM alloy. Complementary, in situ high energy X-ray diffraction experiments in combination with an adapted quenching and deformation dilatometer were conducted for a deeper insight about the deformation behavior of the alloy, i.e. phase fractions and texture evolution as well as temperature uncertainties arising during isothermal and non-isothermal compression. It was found that the presence of β-phase and the contribution of particle stimulated nucleation of ζ-Ti5Si3 silicides and h-type carbides Ti2AlC enhance the dynamic recrystallization behavior during deformation within the (α+β) phase field region, leading to refined and nearly texture-free α/α2-grains. In conclusion, robust deformation parameters for the refinement of critical microstructural defects could be defined for the investigated multi-phase γ-TiAl based alloy.},
note = {Online available at: \url{https://doi.org/10.1016/j.msea.2014.07.040} (DOI). Schwaighofer, E.; Clemens, H.; Lindemann, J.; Stark, A.; Mayer, S.: Hot-working behavior of an advanced intermetallic multi-phase Gamma-TiAl based alloy. Materials Science and Engineering  A. 2014. vol. 614, 297-310. DOI: 10.1016/j.msea.2014.07.040}}