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Superplastic Deformation Behavior of Multi‐Pass Warm Rolled Ti–6Al–4V Titanium Alloy at Low Temperature and High Strain Rate
Author(s) -
Xu Yong,
Yang Xiangjie,
Dong Hongbo
Publication year - 2018
Publication title -
advanced engineering materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.938
H-Index - 114
eISSN - 1527-2648
pISSN - 1438-1656
DOI - 10.1002/adem.201701181
Subject(s) - superplasticity , materials science , strain rate , grain boundary sliding , dynamic recrystallization , metallurgy , activation energy , titanium alloy , microstructure , deformation mechanism , deformation (meteorology) , grain boundary , elongation , alloy , recrystallization (geology) , composite material , ultimate tensile strength , hot working , paleontology , chemistry , organic chemistry , biology
The superplastic deformation behavior of Ti–6Al–4V alloy is investigated by the tensile tests for multi‐pass warm rolled Ti–6Al–4V alloy at temperature of 700–870 °C and strain rate of 10 −3 –10 −2 s −1 . A maximum elongation of 1550% is obtained at temperature of 800 °C and strain rate of 10 −3 s −1 . Even at the low temperature of 700 °C and the high strain rate of 10 −2 s −1 , the elongation is still 356%. The enhanced superplasticity at low temperature and high strain rate is due to the refined microstructure with fragmented and uniformly distributed fine β grains and to the high density dislocation around grain boundaries as well as dynamic recrystallization. The activation energy at temperature of 800 and 870 °C is 226.8 and 220.2 kJ mol −1 , but it increases to 377.5 kJ mol −1 at temperature of 700 °C. The average activation energy is 274.8 kJ mol −1 suggesting that the predominant deformation mechanism is grain boundary sliding. The coefficient of strain rate sensitivity increases with the temperature.