Hydrogen-Induced Amorphization in Ti-Al-Zr Compounds with D0₁₉, B2 and FCC Structures

Abstract

Structural changes and the hydrogen content in pseudobinary Ti₃Al–Zr₃Al, i.e., Ti_1−x−yAl_yZr_x alloys (y=0.25, 0.30 and 0.35) by hydrogenation were examined with a powder X-ray diffractometer (XRD) and a hydrogen analyzer. Single-phases with the D0₁₉ and the B2 structures were formed in the homogenized alloys, while an fcc phase coexisted with the B2 phase. These D0₁₉, B2 and fcc phases changed into an amorphous phase by hydrogenation below 573 K. This is the first report of hydrogen-induced amorphization (HIA) by hydrogenation of a single-phase bcc type (B2) alloy. Furthermore, crystallization behavior of the hydrogen-induced amorphous Ti–Al–Zr alloys was investigated by a differential scanning calorimeter (DSC) and XRD.