Hydrogenation behaviors and characteristics of bulk Ti–6Al–4V alloy at different isothermal temperatures

The bulk Ti–6Al–4V alloy was hydrogenated at the temperature range of 723–973 K, and the hydrogen absorption characteristics and hydrogen absorption kinetics were investigated. The results show that there are two types of hydrogen absorption characteristics at different temperatures. The hydrogen content decreases, and the time reaching reaction equilibrium is shorten with the isothermal hydrogenation temperature increasing. Meanwhile, the mechanism of the hydrogen absorption kinetics is different at different temperatures. The incubation period exists at the initial hydrogen absorption stage below 823 K, and Ka2 (the reaction rate constant of Stage 2) ≫ Ka1 (the reaction rate constant of Stage 1). And there is no incubation period over 823 K, Ka1 ≫ Ka2.