Mechanical alloying and milling of Al–Mg alloys

• Published in: Journal of alloys and compounds Vol. 483; no. 1; pp. 2 - 7
• Main Authors: Scudino, S., Sakaliyska, M., Surreddi, K.B., Eckert, J.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Kidlington Elsevier B.V 01-08-2009; Elsevier
• Subjects: Alloys; Applied sciences; Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; Intermetallics; Mechanical alloying; Metal powders; Metals. Metallurgy; Microstructure; Phase transitions; Physics; Powder metallurgy. Composite materials; Production techniques; Structure of solids and liquids; crystallography; Structure of specific crystalline solids; Intermetallics; Microstructure; Mechanical alloying; Phase transitions; Phase composition; Intermetallic compounds; Magnesium alloys; Solubility; XRD; Lattice parameters; Heat treatments; Binary alloys; Hexagonal lattices; Aluminium alloys; Solid solutions; Phase equilibria
• ISSN: 0925-8388; 1873-4669; 1873-4669
• DOI: 10.1016/j.jallcom.2008.07.161

Solid solubility extension of Mg in Al was achieved for the binary Al–Mg system in the range of 10–40
at.% Mg by mechanical alloying of elemental powder mixtures and by mechanical milling of pre-alloyed ingots. No indication for the formation of the equilibrium phases (β-Al
3Mg
2 and γ-Al
12Mg
17) after milling was observed. The cell parameters of the solid solutions increase linearly with increasing Mg content with a slope that depends on the processing route used. During heating, the Al(Mg) solid solutions prepared from the 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, the β′-phase, a hexagonal intermediate phase with approximate composition Al
3Mg
2, is formed. The β′-phase most likely serves as precursor for the formation of the equilibrium β-Al
3Mg
2 phase, which occurs in the following exothermic event.