Characterization of Ti-based hydrogen absorbing alloys

In this paper, Ti-x wt.% Zr (x = 25, 30, 35) alloys were developed and their hydrogen absorption properties were characterized systematically. Phase structure investigation indicates that experimental Ti-x wt.% Zr (x = 25, 30, 35) alloys are solid solutions with HCP (hexagonal close-packed) structure. And the X-ray diffraction patterns of hydrided alloys showed that the main phase composition is FCC (face-centered cubic) structure, the minority FCC Ti2ZrH4 phase was also observed in hydrided Ti-30 wt.% Zr alloy. Besides, the hydrogen absorption thermodynamic and kinetic properties were characterized, thermodynamic calculation was combined with experiments for the first time, thermodynamic model of the Ti-Zr-H ternary system was developed by using first-principles calculations combined with CALPHAD (CALculation of PHase Diagrams) method, the predicted PCT curves agree well with experimental data. Properties of Ti-x wt.% Zr (x = 0-50) alloys at 573 K were also predicted.