1. College of Mechanical and Electrical Engineering, Shaanxi University of Science & Technology, Xi’an 710021, China
2. Northwest Institute for Nonferrous Metal Research, Xi’an 710016, China
Titanium alloy can be used as a structural material for liquid hydrogen storage and transportation, deep submergence and other lowtemperature tooling under cryogenic conditions due to their excellent high specific strength,corrosion resistance, non-magnetism and good low-temperature plasticity. This paper systematically reviews the research progress of low-temperature mechanical properties of titanium alloys. The lowtemperature tensile test shows that the tensile strength of TA7, CT20, TC4 ELI and other alloys increases significantly with the decrease of test temperature, and the plasticity does not change significantly. The increase of critical shear stress at low temperature makes dislocation slip more difficult to start, thereby resulting in a significant enhancement of the alloy’s strength. The good plasticity at low temperature is attributed to the coupling effect of deformation twinning and multi-system slip. The low-temperature impact test shows that the impact toughness of pure titanium at low temperature is almost unchanged, and the high density twin is the fundamental reason why the impact toughness of pure titanium at low temperature can still maintain the same as that at room temperature. The impact toughness of Ti80, CT20 and TC4 alloys decreases with the decrease of temperature. The weakening of plastic deformation ability and the relatively flat crack propagation path make the impact toughness decrease significantly at low temperature. Finally, the research direction of low-temperature mechanical properties of titanium alloys is prospected, which is necessary to study the low-temperature mechanical properties of highstrength titanium alloys, as well as the low-temperature deformation mechanism and toughening mechanism of additively manufactured titanium alloys.