The Intermetallic Phases in Sand Casting Magnesium Alloys for Elevated Temperature
In the present article, the phase identification of four magnesium alloys: Mg-9wt%Al, Mg-8wt%Al-2wt%Ca-0.5wt%Sr, Mg-5wt%Y-4wt%RE and Mg-3wt%Nd-1wt%Gd were studied. The results showed that Mg-9wt%Al alloy contains only the Mg17Al12 intermetallic phase in α-Mg matrix. As-cast microstructure of Mg-8wt%Al-2wt%Ca-0.5wt%Sr alloy consist of α-Mg matrix with (Al,Mg)2Ca and (Al,Mg)4Sr phases. The Mg-5wt%Y-4wt%RE alloy showed several phases. This alloy was characterized by a solid solution structure α-Mg with eutectic α-Mg + Mg14Y2Nd on grain boundaries. The precipitates of MgY, Mg2Y, Mg24Y5 phases have been also observed. The Mg-3wt%Nd-1wt%Gd alloy composed mainly of a solid solution structure α-Mg with eutectic α-Mg + Mg3(Nd,Gd) on the grain boundaries. The regular precipitates of MgGd3 phase have been also observed.
Hajo Dieringa, Norbert Hort and Karl Ulrich Kainer
A. Kiełbus and T. Rzychoń, "The Intermetallic Phases in Sand Casting Magnesium Alloys for Elevated Temperature", Materials Science Forum, Vol. 690, pp. 214-217, 2011