Phase Transformations in Ti3Sn and Ti2Sn Intermetallics During Hydrogenation

Abstract

The sequence of phase transformations in Ti3Sn and Ti2Sn intermetallics during their interaction with hydrogen is studied. The mechanism whereby Ti3Sn hydride phases form is clarified. It is shown that Ti3Sn reacts with hydrogen at 373–1173 K through hydrogen ordering of the initial intermetallic structure, subsequent amorphization, and restructuring during the formation of hydride phases in the following sequence: hcp Ti3Sn → diamond Ti3SnH0.8 → hcp Ti3SnH0.8–0.9 → fcc Ti3SnH0.9–1.0 → bcc Ti3SnH1+x. A new hydride phase, Ti3SnH1+x (bcc, a = 0.538 nm), with high hydrogen capacity compared to the known fcc Ti3SnH hydride, which decomposes when heated to 1073 K, has been found. Destructive hydrogenation of Ti3Sn at 298–1173 K and hydrogen pressures of 1.0–6.0 MPa is not revealed. It is found that intermetallic Ti2Sn reacts with hydrogen through destructive hydrogenation to form a solution of hydrogen in β-titanium, hydride of a face-centered tetragonal solid solution of tin in titanium, and intermetallic Ti5Sn3.