Metallurgical Abstracts on Light Metals and Alloys vol.57
Microstructure evolution and mechanical properties of Ti-6Al-4Zr-4Nb alloys fabricated by Spark Plasma Sintering (SPS)
S.J.Liang1, S. Matsunaga1, Y. Toda2, T. Matsunaga3 and Y. Yamabe-Mitarai1
1 Department of Advanced Materials Science, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa City, Chiba 277-8561, Japan
2 National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki, 305-0047, Japan
3 Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara City, Kanagawa Prefecture, 252-5210, Japan
[Published in Metall/ Mater. Trans. A, 55A (2024) 2544-2554]
https://doi.org/10.1007/s11661-024-07422-8
E-mail: mitarai.yoko[at]edu.k.u-tokyo.ac.jp
Key Words: Near-α Ti alloy, Lameller structure, Compression strength, Creep, Deformation mechanism
The near-α Ti-6Al-4Zr-4Nb (wt%) alloy is a recently developed alloy with potential for aerospace applications. This study evaluates the microstructure and mechanical properties of Ti-6Al-4Zr-4Nb produced by spark plasma sintering (SPS). The SPS samples sintered in the α + β regions exhibited equiaxed α with a neighboring thin β phase. Above the β-transus temperature, the α/β lamellar structure formed, allowing control of the grain size (100 ~200 µm). The compressive strength and the creep property of the SPS samples were compared with the LBPDed and the forged samples. The compressive strength of the SPS sample was lower than that of the LPBFed sample but similar to the forged sample. The SPS samples exhibited longer creep rupture life (2220 hours) than LPBFed samples (1730 hours), but shorter than the forged sample (4109 hours). The creep deformation mechanism of the lamellar structure in the SPS sample was dislocation creep.