Characterization of Widmanstatten laths and interlocking boundaries in fully-lamellar TiAl-base alloy
- Univ. of Ancona (Italy). Dept. of Mechanics
- Univ. of Science and Technology, Beijing (China). State Key Lab. for Advanced Metals and Materials
Near-gamma titanium aluminides are promising candidates for high-temperature applications in automotive and aerospace industry. Although different types of microstructure have been produced, the fully-lamellar is currently regarded as the most attractive. This kind of microstructure can be characterized by the factors, namely, colony size, lamellar interspacing, the existence of Widmanstaetten (secondary) laths, and the type of grain boundaries (smooth or interlocking). The critical consequence of colony size and interlamellar spacing on the ductility and fracture toughness of TiAl-base alloy has been widely demonstrated. Meanwhile, the presence of Widmanstaetten (Wid-) laths and interlocking (IL-) boundaries was reported to further improve the fracture toughness and creep resistance by dissipation of crack growth and formation of bridging ligaments. Unfortunately, their knowledge on how to develop Wid-laths and IL-boundaries is rather ambiguous. In this paper, the effect of temperature and cooling rate on the Wid-laths and IL-boundary formation was studied, and the angles between the habit plane of Wid-laths and parent lamellae were determined by a specific optical micrographic method.
- OSTI ID:
- 540921
- Journal Information:
- Scripta Materialia, Journal Name: Scripta Materialia Journal Issue: 5 Vol. 37; ISSN 1359-6462; ISSN SCMAF7
- Country of Publication:
- United States
- Language:
- English
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