Emergence of Hydrogen Absorption Ability in Metastable HCP, FCC and Amorphous Ti-Al Alloys Prepared by Mechanical Grinding

Abstract

Titanium aluminides [L1₀-TiAl (Ti_0.50Al_0.50 and Ti_0.40Al_0.60), TiAl₂ and D0₂₂-TiAl₃] have been mechanically ground (MG) in an argon atmosphere. In addition, hydrogen absorption and desorption properties of the MG-alloys have been investigated. Hcp- and amorphous (a-) TiAl, fcc- and a-TiAl₂ and fcc-TiAl₃ are formed by mechanical grinding (MG) of TiAl, TiAl₂ and TiAl₃, respectively. Although original Ti-aluminides do not absorb hydrogen, hcp- and a-TiAl, and fcc- and a-TiAl₂, prepared by MG, having a fresh surface absorb hydrogen of the amount of 0.4−0.1 (H/M). The present work clearly demonstrates that MG is a useful technique for an emergence of the hydrogen absorption ability of intermetallic compounds containing much hydride-forming elements.