Dynamic response and plastic deformation behavior of Ti–5Al–2.5Sn ELI and Ti–8Al–1Mo–1V alloys under high-strain rate

Split Hopkinson pressure bar test system was used to investigate the plastic deformation behavior and dynamic response character of α-type Ti–5Al–2.5Sn ELI and near α-type Ti–8Al–1Mo–1V titanium alloy when subjected to dynamic loading. In the present work, stress–strain curves at strain rate from 1.5 × 103 to 5.0 × 103 s−1 were analyzed, and optical microscope (OM) was used to reveal adiabatic shearing behavior of recovered samples. Results show that both the two alloys manifest significant strain hardening effects. Critical damage strain rate of the two alloys is about 4.3 × 103 s−1, under which the impact absorbs energy of Ti–5Al–2.5Sn ELI and Ti–8Al–1Mo–1V are 560 and 470 MJ·m−3, respectively. Both of them fracture along the maximum shearing strength orientation, an angle of 45° to the compression axis. No adiabatic shear band (ASB) is found in Ti–5Al–2.5Sn ELI alloy, whereas several ASBs with different widths exist without regular direction in Ti–8Al–1Mo–1V alloy.