Hydriding properties of Mg - Al - Zn quasicrystal powder produced by mechanical alloying

Abstract

The stable quasicrystal belonging to the Bergman class based on Mg - Al - Zn (Mg44Al15Zn41) was prepared by the mechanical alloying of elemental powders. The phase structure, chemical composition and hydriding properties of the obtained quasicrystal were investigated by XRD, SEM, EDS, DSC and the volumetric Sievert method. Our results have shown that the Mg44Al15Zn41 quasicrystal is unstable while hydriding above 200 °C and decomposes irreversibly into different Mg - Zn based inter-metallic compounds. While being hydrided at 200 °C, where the quasicrystal is stable, Mg44Al 15Zn41 decomposes mainly into the MgZn2 based intermetallic compound with MgH2 but above 300 °C, where the 2/1 approximant is stable, Mg44Al15Zn41 transforms mainly into the Frank-Kasper phase with MgH2. © by Oldenbourg Wissenschaftsverlag.