Hydrogen Absorption and Desorption Properties of Ti₃Al-Ni Alloys

Abstract

Structures of as-cast and homogenized Ti_75−xAl₂₅Ni_x alloys before and after hydrogenation, the hydrogen content and the hydrogen desorption temperature of the hydrogenated Ti_75−xAl₂₅Ni_x alloys were investigated by a powder X-ray diffractometer (XRD) and a hydrogen analyzer. The hydrogen content of these alloys decreased with increasing Ni content, and was almost independent of the hydrogenation temperature and the structure of the alloys, but 50% hydrogen desorption temperature, T_d, varied widely with them. The formation of amorphous phases raised T_d. On the contrary, a drop in T_d was achieved by hydrogenation of a mixture alloy of the D0₁₉ and C14 Laves phases.