An X-ray investigation of hydrogenated Mg–30Al magnesium alloy

The X-ray diffraction analysis of hydrogenated Mg–30Al magnesium alloy was used to determine the effect hydrogen on phase changes and lattice parameters as well as hydride formation in the investigated alloy. The results of XRD analysis showed that the β-Mg17Al12 phase was significantly affected by hydrogenation up to 12 h causing considerable lattice expansion accompanied by an increase in the interplanar spacing, X-ray line broadening and decrease in crystallite size while the α-Mg phase was slightly affected by hydrogenation treatment. Further hydrogenation (i.e. beyond 12 h) resulted in disappearance of α-Mg and β-Mg17Al12 peaks and formation of MgH2 hydride and aluminum phases in the alloy. The dehydrogenation treatment followed hydrogenation resulted in increasing the lattice parameters of Mg–30Al alloy, decomposition of MgH2 and reappearance of α-Mg peaks as well as disappearance of Al peak throughout the material X-ray diffraction patterns. Dehydrogenation at higher temperature resulted in faster decomposition of MgH2 hydride and more hydrogen diffuses out of the specimens.