Microstructure and Mechanical Properties of Ti62421S High Temperature Titanium Alloy with Different Heat Treatments

Abstract:

In this paper, three different double annealing treatments were applied on the 3mm-thick Ti-6Al-2Sn-4Zr-1Mo-2Nb-0.2Si (Ti62421S) alloy plate. Optical microscopy (OM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and tensile tests were used to investigate the microstructure and mechanical properties under different temperatures of Ti62421S alloy. The results show that the content of primary α phase (α_p) decreases while transformed β structure (βt) increases with the increasing first-stage annealing temperature. After double annealing treatment, ordered α₂ phase particles precipitate within α_p and the size increases with first annealing temperature. This leads to that with increasing first annealing temperature, ultimate tensile strength (UTS) at 600~650°C increases while elongation decreases. After 1000°C/1h/AC+ 750°C/2h/AC annealing, Ti62421S alloy plate exhibits superior combination of mechanical properties at room and elevated temperatures.

• Periodical: Materials Science Forum (Volume 898)
• Pages: 574-578
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.898.574
• Online since: June 2017
• Authors: Xiao Yun Song*, Yong Ling Wang, Wen Jing Zhang, Wen Jun Ye, Song Xiao Hui
• Keywords: Heat Treatment, High-Temperature Titanium Alloy, Mechanical Properties, Microstructure, Stress Rupture, α₂ Phase

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