Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7971651 | Materials Science and Engineering: A | 2018 | 26 Pages |
Abstract
A triple-microstructure with the precipitation of silicide along the α/β phase boundaries and α2 phase in the Ti-5.8Al-3Sn-5Zr-0.5Mo-1.0Nb-1.0Ta-0.4Si-0.2Er alloy was prepared for improving thermal stability and creep resistance. The alloys were forged at 1050â¯Â°C and 1000â¯Â°C followed by solution treatment at 1000â¯Â°C for 1â¯h and subsequent ageing at 700â¯Â°C for 5â¯h. The effects of α morphology and precipitation characteristics on the thermal stability and creep performance of high-temperature titanium alloy were investigated. A triple-microstructure with the participation of silicide along the α/β phase boundary and α2 phase was a promising structure with improved thermal stability and creep resistance. The plasticity loss rate was 25.0% after thermal exposure at 650â¯Â°C for 100â¯h due to the participation and coarsening of α2 and silicide. Meanwhile, the plastic creep strain was 0.111% during the creep deformation at 650â¯Â°C for 100â¯h with an applied stress of 100â¯MPa, which was attributed to the inhibition of silicide and α2 phase for boundary migration and dislocation slipping. Furthermore, the mutual precipitation of coarsening silicide and α2 phase inside α matrix was a significant reason for the dramatic decrease in the thermal ability, which also worsened the inhibition for dislocation climbing of silicon element during the creep deformation.
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Authors
Tongbo Wang, Bolong Li, Zhenqiang Wang, Zuoren Nie,