Berlin 2008 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 23: Poster session

MM 23.14: Poster

Dienstag, 26. Februar 2008, 14:45–18:00, Poster B

Mechanical alloying and milling of Al-Mg alloys — •Mira Sakaliyska, Kumar Babu Surreddi, Sergio Scudino, and Jürgen Eckert — IFW Dresden, Institut für Komplexe Materialien, Postfach 270116, D-01171 Dresden, Germany

Solid solubility extension far beyond the room temperature equilibrium value was achieved by mechanical alloying of elemental powder mixtures for the binary Al-Mg system in the range of 10 - 50 at.% Mg. The Al(Mg) solid solutions are metastable and transform into the equilibrium phases during heating. No indication for the formation of the equilibrium phases (beta-Al3Mg2 and gamma-Al12Mg17) during milling was detected. Similar results can be achieved by mechanical milling of intermetallic compounds. For example, for Al60Mg40 mechanical alloying and milling yield the same metastable supersatured solid solution as end product. Upon heating, the milled powders prepared from different starting materials display a complex behavior characterized by several exothermic events. At low temperatures, an increasing amount of Mg is rejected from the solid solution with increasing temperature. At higher temperature, a hexagonal phase with composition Al3Mg2, is formed. The subsequent exothermic events correspond to formation and growth of the equilibrium beta-Al3Mg2 phase. Finally, selected examples for the mechanical deformation behavior of consolidated samples are presented, revealing encouraging properties regarding the combination of high strength and good ductility at room temperature.