Effect of Heat Treatment on the Microstructure Evolution of Ti-6Al-3Sn-3Zr-3Mo-3Nb-1W-0.2Si Titanium Alloy

Abstract:

Ti-6Al-3Sn-3Zr-3Mo-3Nb-1W-0.2Si (BTi-6431S) alloy is a novel two-phase high temperature titanium alloy for short-term using in aerospace industry up to 700°C. The effects of heat treatment on the microstructure evolution of BTi-6431S alloy bar were investigated through optical microscopy (OM), X-ray diffraction (XRD), electron probe microanalysis (EPMA) and transmission electron microscopy (TEM). The results show that solution treatment in β region at 1010°C followed by water quenching results in the formation of orthorhombic martensite α′′ phase, while air cooling leads to the formation of hexagonal martensite α′ phase. When solution-treated in α+β phase field at temperatures from 900°C to 980°C following by water quenching, the content of primary α phase decreases with the increase of heat treatment temperature. For the alloy subjected to identical heat treatment, the content of Al in α phase is much higher than that in β phase, while the contents of Nb, Mo and W elements in α phase are much less than those in β phase.

• Periodical: Materials Science Forum (Volume 879)
• Pages: 1828-1833
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.879.1828
• Online since: November 2016
• Authors: Xiao Yun Song*, Wen Jing Zhang, Teng Ma, Wen Jun Ye, Song Xiao Hui
• Keywords: Heat Treatment, High-Temperature Titanium Alloy, Martensite, Microstructure

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