Study of electrochemical hydride formation on a grade 2 titanium alloy

In the aim to understand the influence of hydride formation and hydrogen diffusion on the stress corrosion cracking behaviour of grade 2 titanium, cathodic polarization of samples from 30 minutes to 48 hours in a diluted sulfuric acid solution was implemented. Using XRD analyses, the hydride layer formed on the surface was identified as a cubic TiH₂ structure and appears to have a column-shaped microstructure according to SEM observations. Mechanical stress has also a significant influence on hydride formation. A high tension stress shifts the morphology of the hydride layer and promotes the penetration of hydride. (authors)