Section of isothermic tetrahedron of the Al-rich portion of the Al-Mg-Sc-Zr system at 500 deg C

Alloys of the system Al-Mg-Sc-Zr quenched from 500 deg C, containing up to 3% Sc and 4% Zr at contant content of magnesium, being 6%, were investigated. The studies were carried out by the methods of microstructural, microelectron-probe, X-ray diffraction and X-ray analyses. It is ascertained that in the studied range of concentrations phases Al3Sc and Al3Zr can be in equilibrium with aluminium base solid solution. Zirconium solubility in Al3Sc phase and scandium solubility in Al3Zr phase were determined. Cross section of isothermal tetrahedron of the Al-Mg-Sc-Zr system at 500 deg C was plotted. The cross section cuts across two phase volumes α+Al3Sc and α+Al3Zr and three phase volume α+Al3Sc+Al3Zr