Atomic-scale investigation of hydrogen distribution in a Ti-Mo alloy

Ingress of hydrogen is often linked to catastrophic failure of Ti-alloys. Here, we quantify the hydrogen distribution in fully beta and alpha + beta Ti-Mo alloys by using atom probe tomography. Hydrogen does not segregate at grain boundaries in the fully beta sample but segregates at some alpha/beta phase boundaries with a composition exceeding 20 at.% in the alpha + beta sample. No stable hydrides were observed in either sample. The hydrogen concentration in beta phases linearly decreases from similar to 13 at. % to similar to 4 at. % with increasing Mo-content, which is ascribed to the suppression of hydrogen uptake by Mo addition. (C) 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.