Abstract

MARTINEZ, Carola et al. Mg₂Ni_0.5Co_0.5 compound obtaining by mechanical alloying and their performance on hydriding process. Dyna rev.fac.nac.minas [online]. 2017, vol.84, n.200, pp.240-246. ISSN 0012-7353.  https://doi.org/10.15446/dyna.v84n200.51358.

This work presents the microstructural evolution of mechanically alloyed Mg2Ni0.5Co0.5 and a study of its hydriding properties. Mg, Ni, and Co elemental powders (atomic ratios of 2:0.5:0.5, respectively) were mechanically alloyed in a Spex 8000D high-energy mill for 36 h (amorphous sample) and subsequently submitted to a thermal treatment at 673 K for 15 min (nanocrystalline sample). The characterizations of the samples were performed with X-ray diffraction. A Sievert-type volumetric hydriding process was done at 363 K and with hydrogen pressure of 2 MPa. Desorption process was evaluated through differential scanning calorimetry. Based on the obtained results, it is possible to conclude that the amorphous structure absorbs more hydrogen, reaching a maximum of 3.6 wt. % H. Desorption process events depend on amorphous or nanocrystalline states.

Keywords : Hydrogen Storage; Nanostructured Materials; Mechanical Alloying; Magnesium.

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