An investigation on structure, deformation and fracture of hydrides in titanium with a large range of hydrogen contents

The deformation and fracture behaviors of delta hydrides in cyclic strained titanium containing 350, 720 and 930 ppm hydrogen were investigated and compared to that of gamma hydrides in 77 ppm hydrogen specimens. It was found that the gamma and delta hydrides, respectively, in 77 and 350 ppm hydrogen specimens could be plastically deformed readily along with the matrix without fracture, while the delta hydrides at hydrogen contents more than 720 ppm can be either plastically deformed or cleavage fractured, depending on their sizes, orientations. and interactions with localized matrix deformation. The crystallographic, microstructural and micromechanical mechanisms for hydride behavior were discussed. (C) 2004 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.