Mechanical response and effects of β-to-α phase transformation on the strengthening of Ti-10 V-2 Fe-3 Al during one-dimensional shock loading

Plate impact experiments and quasistatic reload compression tests were conducted on a typical metastable beta-titanium alloy, Ti-10 V-2 Fe-3 Al, to investigate its mechanical response and strengthening behavior under one-dimensional shock-loading conditions. The Hugoniot elastic limit (HEL) for this alloy was measured to be 2.89 GPa using a velocity interferometer (VISAR). The shock Hugoniot was also determined by measuring the stress, shock, and particle velocity as independent variables using manganin stress gauges. The fitted shock parameters (C-0 and S) of Ti-10 V-2 Fe-3 Al were found to be nearly identical to those of the alpha+beta-titanium alloy Ti-6 A1-4 V. However, the measured Hugoniot in the stress-particle velocity space lied slightly above that of Ti-6 Al-4 V due to the higher density of Ti-10 V-2 Fe-3 Al. The results of the quasistatic reload compression tests show that the postshock Ti-10 V-2 Fe-3 Al is strengthened. The martensitic (beta-to-alpha '') phase transformation during shock wave loading may play a crucial role in the strengthening of this alloy. Finally, the inflection point corresponding to the phase transition was not observed in the VISAR trace even though the occurrence of the beta-to-alpha '' phase transformation was confirmed by microstructural analyses. The unobserved inflection point can be attributed to the difficulty in resolving the break of the wave fronts due to a very small or no change in the specific volume resulting from the martensite transformations. (C) 2012 Elsevier B.V. All rights reserved.