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Recrystallization and phase transitions in a γ-TiAl-based alloy as observed by ex situ and in situ high-energy X-ray diffraction

Journal Article


Abstract


  • High-energy synchrotron X-ray diffraction is a novel and powerful tool for bulk studies of materials and is applied to the investigation of a high Nb-bearing γ-TiAl-based alloy. The results determined from ex situ diffraction patterns of differently heat-treated samples are compared with those from metallographic examinations. The diffraction angles and also the morphology of reflections on the Debye-Scherrer rings are evaluated in order to determine lattice parameters and grain sizes as well as crystallographic correlation. An in situ heating cycle from room temperature to 1362 °C has been conducted starting from massively transformed γ-TiAl. With increasing temperature, the occurrence of strain relaxation, chemical and phase separation, domain orientations, phase transitions, recrystallization processes, and subsequent grain growth can be observed. Finally, a fully lamellar structure, well oriented with respect to the high-temperature phase, is formed. The data obtained by high-energy synchrotron X-ray diffraction, which contain extremely rich information, are interpreted step by step and relate well with the ex situ observations and metallographic examinations. © 2006 Acta Materialia Inc.

Publication Date


  • 2006

Citation


  • Liss, K. D., Bartels, A., Clemens, H., Bystrzanowski, S., Stark, A., Buslaps, T., . . . Schreyer, A. (2006). Recrystallization and phase transitions in a γ-TiAl-based alloy as observed by ex situ and in situ high-energy X-ray diffraction. Acta Materialia, 54(14), 3721-3735. doi:10.1016/j.actamat.2006.04.004

Scopus Eid


  • 2-s2.0-33746210060

Start Page


  • 3721

End Page


  • 3735

Volume


  • 54

Issue


  • 14

Abstract


  • High-energy synchrotron X-ray diffraction is a novel and powerful tool for bulk studies of materials and is applied to the investigation of a high Nb-bearing γ-TiAl-based alloy. The results determined from ex situ diffraction patterns of differently heat-treated samples are compared with those from metallographic examinations. The diffraction angles and also the morphology of reflections on the Debye-Scherrer rings are evaluated in order to determine lattice parameters and grain sizes as well as crystallographic correlation. An in situ heating cycle from room temperature to 1362 °C has been conducted starting from massively transformed γ-TiAl. With increasing temperature, the occurrence of strain relaxation, chemical and phase separation, domain orientations, phase transitions, recrystallization processes, and subsequent grain growth can be observed. Finally, a fully lamellar structure, well oriented with respect to the high-temperature phase, is formed. The data obtained by high-energy synchrotron X-ray diffraction, which contain extremely rich information, are interpreted step by step and relate well with the ex situ observations and metallographic examinations. © 2006 Acta Materialia Inc.

Publication Date


  • 2006

Citation


  • Liss, K. D., Bartels, A., Clemens, H., Bystrzanowski, S., Stark, A., Buslaps, T., . . . Schreyer, A. (2006). Recrystallization and phase transitions in a γ-TiAl-based alloy as observed by ex situ and in situ high-energy X-ray diffraction. Acta Materialia, 54(14), 3721-3735. doi:10.1016/j.actamat.2006.04.004

Scopus Eid


  • 2-s2.0-33746210060

Start Page


  • 3721

End Page


  • 3735

Volume


  • 54

Issue


  • 14