Related Experiment Video
Updated: Mar 19, 2026
11:17
Spark Plasma Sintering Apparatus Used for the Formation of Strontium Titanate Bicrystals
Published on: February 9, 2017
10.4K
Polysynthetic twinned TiAl single crystals for high-temperature applications
Guang Chen1, Yingbo Peng1, Gong Zheng1
1Engineering Research Center of Materials Behavior and Design, Ministry of Education, Nanjing University of Science and Technology, Nanjing 210094, China.
Nature Materials
|June 21, 2016
Summary
This study introduces a new method for creating titanium-aluminum-niobium (TiAlNb) single crystals for high-temperature applications. The novel directional solidification technique avoids complex seeding, enabling enhanced mechanical properties for aerospace uses.
Area of Science:
- Materials Science
- Metallurgy
- Crystallography
Background:
- Titanium-aluminum (TiAl) alloys offer lightweight properties, corrosion resistance, and high-temperature strength, making them suitable for demanding applications.
- Existing methods for fabricating polysynthetic twinned TiAl single crystals, such as crystal-seeding, present significant challenges and limit service temperatures.
Purpose of the Study:
- To develop a novel method for fabricating TiAl single crystals with controlled lamellar orientations.
- To overcome the limitations of current crystal-seeding techniques for TiAl alloys.
- To investigate the high-temperature mechanical properties of the newly fabricated TiAlNb single crystals.
Main Methods:
- Directional solidification was employed to grow Ti-45Al-8Nb single crystals with controlled lamellar orientations.
- No complex seeding methods were required for crystal fabrication.
- Tensile properties and creep resistance were evaluated at room temperature and 900°C.
Main Results:
- Ti-45Al-8Nb single crystals with 0° lamellar orientation demonstrated an average room temperature tensile ductility of 6.9% and a yield strength of 708 MPa.
- Extensive nanotwin formation during plastic deformation contributed to a failure strength of 978 MPa.
- At 900°C, the alloy maintained a high yield strength of 637 MPa with 8.1% ductility and exhibited superior creep resistance.
Conclusions:
- Directional solidification offers a viable method for producing TiAlNb single crystals with controlled orientations, bypassing complex seeding procedures.
- The fabricated TiAlNb single crystals possess excellent mechanical properties at both room and elevated temperatures, including high strength, ductility, and creep resistance.
- This TiAl single-crystal alloy holds significant potential for advanced applications in aeronautics and aerospace requiring high-temperature performance.
