Microstructure and Creep Properties of Silicon- and/or Germanium-Bearing Near-α Titanium Alloys

Abstract:

The effects of Si and/or Ge addition on the microstructure and creep properties at 650°C and 137 MPa were investigated in near-α Ti–Al–Sn–Zr–Mo alloys. Si and/or Ge addition decreased the minimum creep strain rate owing to the solid solution of Si and Ge in the matrix and the precipitation of silicide, germanide, and their solid solutions. The decrease in the minimum creep strain rate in the alloy with 1 wt% Ge without Si was the most significant because of the formation of very fine germanide precipitates. In addition, a marked shift in the lattice parameters of the α and β phases was detected for the alloy with 4 wt% Ge. The Moiré fringe patterns at the α/β interfaces in the alloys were investigated using high-resolution transmission electron micrographs to discuss the alloying effect on the structure of the interfaces.

• Periodical: Materials Science Forum (Volume 879)
• Pages: 2324-2329
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.879.2324
• Online since: November 2016
• Authors: Tomonori Kitashima*, K.S. Suresh, T. Hara, Yoko Yamabe-Mitarai, Y. Toda
• Keywords: Creep, Germanium, Interface, Silicon, Titanium Alloys

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