Mechanical alloying of Ti45Zr38Ni17 powder mixture forms an amorphous phase, but subsequent annealing causes the formation of an icosahedral (i) phase. The maximum hydrogen concentration that can be loaded at 573 K at a hydrogen pressure of 3.8 MPa is the same ([H]/[M] ≈ 1.5) for the amorphous and i-phase powders. With hydrogenation, the i-phase is almost stable, forming no hydrides, whereas the amorphous phase transforms to a fcc hydride. The activation energy for hydrogen desorption for the i-phase is about 127 kJ mol-1, which is lower than that for the amorphous phase, suggesting that the i-phase powder may have better properties for hydrogen-storage applications.
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