摘要
Strain rate is a critical factor influencing the mechanical response of hexagonal close-packed titanium under cryogenic conditions.In this study,uniaxial tensile tests were performed on commercially pure titanium at 77 K over a broad strain rate range from 0.001 to 1 s^(-1).A critical strain rate of approximately 0.5 s^(-1)was identified,above which ductility exhibits a pronounced reduction,whereas below this threshold,ductility remains relatively stable.Through comprehensive analyses of strain evolution,deformed microstructure,and fracture morphology,this behavior is attributed to severe localized adiabatic heating resulting from inhomogeneous deformation,rather than conventional twin or shear mechanisms.
基金
financially supported by the National Key Research&Development Plan(No.2022YFE0110600)
the National Natural Science Foundation of China(Nos.52171117,52371113,92263201 and 52175306)
Qing Lan Project(No.54944004)
the Basic Research Program of Jiangsu(Nos.BK20232011 and BK20232025)
the Postdoctoral Fellowship Program of CPSF(No.GZC20233481)
Tuoyuan project of Nanjing Tech University(No.20230113)
