Effect of hydrogen on superelasticity of the titanium nickelide-based alloy

The hydrogen effect on the inelastic properties and plastic strain development after electrolythical hydrogenation in physiological solution was investigated. This effect virtually results in a failure under torsion of Ti49.1Ni50.9 (atom per cent) alloy specimens with coarse-grained (CG) and submicrocrystalline (SMC) structures. It is shown that hydrogen embrittlement (HE) phenomenon occurs irrespective of the grain size in the studied specimens at approximately equal strain values. However, compared to the specimens with CG structure, those with SMC structure accumulate two to three times more hydrogen for the same hydrogenation time. It is found that hydrogen has a much smaller effect on the inelastic properties of specimens with SMC structure as compared to those with CG structure.