Hydrogen-Induced Defects in Titanium

Abstract:

The aim of this work was investigation of hydrogen interaction with defects in Ti. Well-annealed Ti samples were loaded with hydrogen either electrochemically or using H₂ gas phase. The hydrogen content and the phase composition of hydrogen loaded samples was determined by thermogravimetric analysis and by X-ray diffraction (XRD) respectively. Positron lifetime (LT) spectroscopy was employed for investigation of defects created by hydrogen loading. High-temperature H₂ gas loading led to complete transformation of the whole sample into δ-TiH₂ while low-temperature H₂ gas loading and the electrochemical loading resulted in a non-uniform structure with most of the hydrogen absorbed in a sub-surface layer. All hydrogen-loaded samples exhibit positron lifetime component of ≈ 170 ps corresponding to positrons trapped at dislocations. Vacancy clusters were observed in the electrochemically loaded sample and the H₂ gas phase loaded sample at low temperature.

• Periodical: Defect and Diffusion Forum (Volume 373)
• Pages: 122-125
• DOI: https://doi.org/10.4028/www.scientific.net/DDF.373.122
• Online since: March 2017
• Authors: Petr Hruška*, Jakub Čížek, František Lukáč, Jan Knapp, Sylvie Mašková, Jan Drahokoupil, Oksana Melikhova, Ivan Procházka
• Keywords: Defect, Hydrogen, Positron Annihilation, Titanium

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