Breaking the continuous hydride network in hydrogen-charged pure titanium to repair hydride–induced performance degradation by applying a pulsed electric current

Abstract

Titanium readily reacts with hydrogen to form hydrides, which greatly deteriorates their mechanical properties. In particular, the continuous hydride network provides a path for crack initiation and propagation. In this study, the hydrogen–charged pure titanium with continuous hydride network were treated by electropulsing treatment and traditional heat treatment. It was found that the elongation of the hydrogen–charged pure titanium were effectively repaired after the electropulsing treatment, while the heat treatment failed. The recovery of elongation of the hydrogen–charged pure titanium can be attributed to the disintegration of the continuous hydride network and the decrease of hydrogen content after the electropulsing treatment. Due to the different electrical properties of the hydrides and the Ti-matrix, the current in hydrogen-charged pure titanium is not uniformly distributed, resulting in the decomposition of the continuous hydride network at lower than conventional tempering temperatures. This particular method can not only be used for the repair of hydride–induced embrittlement, but also can be extended to the optimization of thermo–hydrogen treatment of titanium alloys and the rapid hydrogen release of metal–hydride hydrogen storage materials.