The Al-rich corner of the Al-Fe-Mn-Si System

The goal of this work was to establish in the Al-rich corner (<50 at. % Al) of the ternary Systems Al-Mn-Fe, Al- Fe-Si and Al-Mn-Si two isothermal sections at 550 C and 700 C, respectively, and to investigate the influence of Si additives on the alloying behaviour of Al-rich compounds. The temperature of 550 C was employed because of the final annealing temperature of industrial Al-production. The second temperature was chosen to study the solidification behaviour of multicomponent phases in liquid Al. Aluminium based light alloys of industrial interest generally belong to multicomponent systems which imply at least one matrix element and two or more elements (as primary, secondary alloying partners, impurity or trace elements). To provide the property/cost combinations of industrial production typically five components are added to current aluminium alloys as (a) primary alloying elements (Mn, Mg, Si, Cu, Zn), (b) as secondary elements (Cr, Ti, Zr) or (c) left as impurities (Fe). The system Al-Mn-Fe-Mg-Si (Cu,Zn) is the key system of the Al-industry of today covering a wide range of applications such as extrusion alloys for transportation and construction purposes, electrical wires, canning alloys for packaging and cast alloys. The seven component system Al-Mn-Fe-Mg-Si-Cu- Zn, denoted a key system in the COST 507 action, contains not only a wealth of intermetallic phases (thermodynamically stable or metastable and many of them ternary and even quarternary or of higher order) but also significant and far ranging solid solutions for the various alloying elements in Al critical to most industrial processes.