Fabrication and hydrogen storage property study of nanostructured Mg-Ni-B ternary alloys

Mg-Ni-B ternary alloys with nanostructure were produced by mechanical alloying method. Alloys with various structures were obtained. X-ray diffraction was used to define the structure and phase information as well as crystalline size of the alloys. Bright-field and dark-field transmission electron microscope (TEM) technique was applied to observe the morphology of the samples. Electron diffraction was used to confirm the structure of the alloys. The hydrogen storage properties of the obtained Mg-Ni-B alloys were studied by high pressure differential scanning calorimetry (DSC) and pressure-composition isotherm (PCT) methods. Body centered cubic (BCC) structure alloys show better hydrogen absorption properties than CsCl and Mg2Ni type structure alloys in this work. Mg48Ni48B4 and Mg50Ni45B5 BCC alloys showed a hydrogen absorption content of 1.93 and 1.94 mass% at 373 K. Substitution or addition of a small amount of B to Mg50Ni50 alloy is effective to improve hydrogen storage properties.