Microstructure evolution, hot deformation behavior and mechanical properties of Ti-43Al-6Nb-1B alloy

Producing fully-lamellar microstructure for wrought beta-gamma TiAl alloys without single α-phase field

“…It is conventional method to anneal the TiAl materials within aphase field for a proper time to produce FL microstructures, for both a þ g two-phase TiAl [4] and multi-phase beta-gamma ones [3], regardless of their processing conditions. As to the casting betagamma TiAl without single a-phase field, for example the present as-cast TiAle4/6Nbe2MoeB/Y alloys, the solidification pathway is…”

“…[1,2]. To obtain such FL microstructure for engineering application targets, thermo-mechanical processing (TMP) combined with post processing heat treatment is necessary [3,4].…”

Microstructure and high temperature mechanical properties of powder metallurgical Ti-45Al-7Nb-0.3W alloy sheets

“…5 (b), (c) and (f)). And it is regarded as an important deformation mechanism because of its capability to enhance the plasticity of the alloy to some extent [15]. Fig.…”

“…At low temperature, the β phase can turn into ordered B 2 phase. The B 2 phase is hard and brittle and detrimental to the ductility of the alloy at relatively low temperature [15,34], which can explain the low elongation of 2% at room temperature. But the β phase is soft and ductile at elevated temperature.…”

“…In comparison to a conventional Ti-47Al-2Cr-0.2Si alloy, they showed a considerable increase in strength. Nevertheless, the high addition of Nb may bring some problems as well, such as poor hot deformability and low room temperature ductility [12,15]. Thus, more studies on high Nb containing TiAl alloys should be carried out.…”