Microstructure evolution in cast Ti-37Al alloys with B additions
(1. School of Materials Science and Engineering,
Harbin Institute of Technology, Harbin 150001, China;
2. School of Materials Science and Engineering,
Beijing University of Aeronautics and Astronautics, Beijing 100083, China)
Harbin Institute of Technology, Harbin 150001, China;
2. School of Materials Science and Engineering,
Beijing University of Aeronautics and Astronautics, Beijing 100083, China)
Abstract: Ti-37Al-B alloys were produced by in-situ synthesis method. The phase constituent and the microstructure were studied by XRD and SEM. The results show that the borides in Ti-37Al-B alloys evolve from fibrous TiB to fibrous TiB+coarse TiB and eventually to fibrous TiB+coarse TiB+blocky TiB2 as the B content increases. The eutectic TiB is fibrous and the primary TiB is coarsely needlelike, but the TiB2 particles exhibit hexagonal prism morphology. The solidification paths also were analyzed.
Key words: TiB; TiB2; titanium alloy; solidification paths