Fabrication and Microstructure of Layers Containing Intermetallic Phases on Magnesium

Al- and Al/Zn-enriched layers containing intermetallic phases were deposited on the Mg substrate by heating the Mg specimens in contactwith the powdered materials in a vacuum furnace. The Al-enriched surface layers were produced using Al powder, whereas the Al/Znenriched layers were obtained from an 80 wt.% Al + 20 wt.% Zn powder mixture. The microstructure and composition of the layers wereanalyzed by optical microscopy, scanning electron microscopy and X-ray diffraction. The results showed that the Al-enriched layercomprised an Mg17Al12 intermetallic phase and a solid solution of Al in Mg. The layer obtained from the Al+Zn powder mixture wascomposed of Mg-Al-Zn intermetalic phases and a solid solution of Al and Zn in Mg. Adding 20% of Zn into the Al powder resulted in theformation of a considerably thicker layer. Moreover, the hardness of the surface layers was much higher than that of the Mg substrate.