TY - JOUR
T1 - Recrystallization and phase transitions in a γ-TiAl-based alloy as observed by ex situ and in situ high-energy X-ray diffraction
AU - Liss, Klaus Dieter
AU - Bartels, Arno
AU - Clemens, Helmut
AU - Bystrzanowski, Slawomir
AU - Stark, Andreas
AU - Buslaps, Thomas
AU - Schimansky, Frank Peter
AU - Gerling, Rainer
AU - Scheu, Christina
AU - Schreyer, Andreas
N1 - Funding Information:
The authors appreciate assistance from Hermann Franz, Anita Ehnes, and Reinhard Kampmann at the PETRA beamline; Heinz-Günther Brockmeier and Wenhai Ye for supplying a first mirror furnace; and Nozomu Hiraoka for setting up the furnace at the ESRF. Likewise, we are grateful for the beam-time and overall support delivered at HASYLAB and ESRF. Three of the authors (A.B., H.C., and R.G.) acknowledge gratefully the financial support of the Deutsche Forschungsgemeinschaft (DFG).
PY - 2006/8
Y1 - 2006/8
N2 - 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.
AB - 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.
KW - Synchrotron radiation
KW - Titanium aluminides
UR - http://www.scopus.com/inward/record.url?scp=33746210060&partnerID=8YFLogxK
U2 - 10.1016/j.actamat.2006.04.004
DO - 10.1016/j.actamat.2006.04.004
M3 - 文章
AN - SCOPUS:33746210060
VL - 54
SP - 3721
EP - 3735
JO - Acta Materialia
JF - Acta Materialia
SN - 1359-6454
IS - 14
ER -