Hydrogen desorption properties of melt-spun and hydrogenated Mg-based alloys using in situ synchrotron X-ray diffraction and TGA

Three magnesium-based alloys, Mg90Ni10, Mg 80Ni10Y10 and Mg85Cu 5Ni5Y5, were prepared by melt-spinning and compared regarding their hydrogen desorption properties. Their hydrogen desorption kinetics after activation and hydrogenation was investigated by thermogravimetry at different temperatures in the range from 150 °C to 250 °C. It was found that Mg80Ni10Y10 exhibits a much faster desorption kinetics in comparison to Mg90Ni 10 and Mg85Cu5Ni5Y5 of up to 1.3 wt.%-H2/min. The corresponding crystal phase transformations were investigated in detail by in situ synchrotron X-ray diffraction. It was found that the kinetics of hydrogenation is controlled by different reaction pathways for Mg90Ni10, Mg80Ni 10Y10 and Mg85Cu5Ni 5Y5.