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A Comparative Study on Microstructure and Mechanical Properties of Ti‐43/46Al–5Nb–0.1B Alloys Modified by Mo
Author(s) -
Yang Yong,
Fang Hongze,
Chen Ruirun,
Su Yanqing,
Ding Hongsheng,
Guo Jingjie
Publication year - 2020
Publication title -
advanced engineering materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.938
H-Index - 114
eISSN - 1527-2648
pISSN - 1438-1656
DOI - 10.1002/adem.201901075
Subject(s) - microstructure , materials science , metallurgy
To improve mechanical properties of TiAl–Nb alloys and obtain effects of Al content on microstructure, Ti‐43/46Al–5Nb–0.1B– x Mo alloys are prepared. Phase constitution, macro‐/microstructure volution, and mechanical properties of them are investigated systematically and compared in detail. Results show that the lamellar colony size refines, B2 phase increases and Al‐segregation in interdendritic regions aggravates with the increase in Mo content. The increased B2 phase is attributed to the increased Mo segregated at the grain boundaries during β/α transformation, and the aggravated Al‐segregation is attributed to the increased Al rejected into the interdendritic areas during L/β solidification. Compressive results show that the strength and strain increase about 150 MPa and 6% when the Mo content increases to 0.8 at% for Ti‐43Al–5Nb–0.1B– x Mo alloys; they increase about 343 MPa and 4% when Mo content increases to 1.2 at% for Ti‐46Al–5Nb–0.1B– x Mo alloys. Both the strength and strain decrease when Mo content further increases. The grain refinement strengthening and solid solution strengthening caused by Mo are contributed to the improved strength and strain. However, excessive B2 phase and severe Al‐segregation deteriorate the mechanical properties of the alloys, which act as the cracking sources.