Hot deformation behavior of a near alpha titanium alloy with/without thermal hydrogen processing

The true stress-true strain curves of Ti-6Al-2Zr-1Mo-1V alloy with hydrogen were obtained by hot compression test. The microstructures of the alloy before and after thermo-compression were observed. The apparent activation energies of deformation were calculated for the alloy with and without hydrogen. The behavior and mechanism of deformation for hydrogenated Ti-6Al-2Zr-1Mo-1V alloy at high temperature were analyzed. The relationship between hydrogenation time and hydrogen content at 800 °C can be expressed as the equation: C _H(t)=1.2-1.2exp(-t/120). The true stress-true strain curves of hot compression for Ti-6Al-2Zr-1Mo-1V alloy with hydrogen first move down and then move up as hydrogen content increases. Appropriate hydrogen content can reduce the peak of flow stress to minimal value. The apparent activation energies of deformation of the alloy with 0.47% hydrogen content and without hydrogen were calculated as 140 kJ·mol^-1 and 390 kJ·mol^-1, respectively, at 800 °C and at strain rate 8.3×10^-4 s ^-1. The apparent activation energy of deformation increases when the strain rate enhances from 8.3×10^-4 s^-1 to 8.3×10^-2 s^-1.