The study of the distribution of the transition metals and Si during primary precipitation of the intermetallic phases in Al–Mn–Si alloys

In this paper, the initial results of the metallographic examinations of the intermetallic phases precipitates formed during the peritectic transformation in the Al–Mn(Fe, Cr)–Si alloys were shown. The distribution of the alloy components, Si, Mn, Fe and Cr, in the observed precipitates was estimated by means of the X-ray microanalysis (EDS). The influence of Mn/Fe ratio on the chemical composition of the intermetallic phase was established. The observed changes of the chemical composition of the phase constituents reflected indirectly the process of the mutual substitution of the atoms in the crystal lattice: Al ↔ Si and Mn ↔ Fe. The evolution of the morphology of the peritectic α-AlMn(Fe)Si phase (from continuous layer, by Chinese script, to polyhedron shape) was shown when Fe was added into Al–Mn–Si alloy.