Hydrides in alpha-Ti: Characterization and effect of applied external stresses

摘要

The hydrides precipitated in commercially pure titanium, produced by cathodic hydrogenation followed by a thermal diffusion treatment, have been characterized using optical and electron microscopy. 5 and y-hydrides have been observed in specimens with low hydrogen concentrations (< = 500 wppm). Hydrides with {0110} habit plane were the most abundant ones. Hydrides with {0001} and {1017} habit planes, both with the same matrix-hydride crystallographic relationship, have also been recognized. The {1012} habit plane was confirmed by transmission electron microscopy with a {01111}//{001} and (2110)//(110) orientation relationship. The distribution of the orientation of the hydride platelets was studied with increasing levels of constant load applied during a cooling process. The relative frequency of precipitated hydrides in planes perpendicular to the tensile axis was increased and this was more remarkable when the orthogonal plane corresponds to a prismatic plane.