Effect of hydrogen on the fracture properties and microstructure of Ti-6Al-4V

Abstract

A Ti-6Al-4V alloy was hydrogenated to various levels and subjected to fracture toughness and conventional tensile testing. The results indicate that these particular properties are not unduly influenced by hydrogen contents of up to 490 ppm. Furthermore, the fracture resistance was not affected by a 20 h hold on load, although sustained load cracking did occur at high hydrogen contents. Nevertheless, transmission electron microscopy revealed that, at hydrogen concentrations in excess of 225 ppm, strain-induced hydride precipitation occurred ahead of the loaded crack tip.