Structure and hydrogen absorption property of Mg₂Ni-Ti alloy powders prepared by mechanical alloying

In the present study, pure Mg, Ni, and Ti powder mixtures were mechanically alloyed as compositions of (Mg2Ni)100-xTix (x=0, 2.5, 5, 7.5 or 10 respectively). The structure evolution of as-milled powders were examined by X-ray diffraction and synchrotron X-ray absorption spectroscopy. For all compositions investigated, nanocrystalline (Mg 2Ni)100-xTix alloy powders were synthesized at the end of milling. The hydrogen absorption properties of the 15h as-milled powders were evaluated by a Sieverts type apparatus at a temperature of 300, 325 and 350°C respectively. Improvement of the hydrogen absorption properties was observed with the titanium additions. At a temperature of 350°C and a H2 pressure of 50 atm, the (Mg2Ni)95Tis as-milled powders exhibited a maximum hydrogen absorption value and reversible content of 3.88 and 3.01 wt.% respectively.