Al-Si substitution in α-phase AlMnSi

The alpha -phase of the Al-Mn-Si ternary system has been precipitated from four liquid solutions (2.8 wt% Mn-3.7 wt% Si, 4.5 wt% Mn-7 wt% Si, 7.7 wt% Mn-10 wt% Si and 8.7 wt% Mn-12.6 wt% Si) and equilibrated slightly over the melting point of the (secondary) solid solution. Quenching into water enabled the precipitates to be separated from the solid solution and the co-nodal tie-lines for the alpha -phase and liquid to be determined. The silicon content varied from 9.8 to 11.8 wt%, while the manganese content, 29.6 plus or minus 0.6 wt%, did not vary significantly. The lattice parameter of the cubic unit cell decreased from 1.267 6(2) nm to 1.265 10(4) nm with increasing silicon.