Effects of casting process on microstructures and flow stress behavior of Mg–9Gd–3Y–1.5Zn–0.8Zr semi-continuous casting billets

Mg–9Gd–3Y–1.5Zn–0.8Zr alloys own high strength, good heat and corrosion resistance. However, it is difficult for the fabrication of large-scale billets, due to the poor deformation ability and strong hot-crack tendency. This work investigated the casting process on the microstructures and flow stress behaviors of the semi-continuous casting billets for the fabrication of large-scale Mg–9Gd–3Y–1.5Zn–0.8Zr billets. The casting process (electromagnetic intensity and casting speed) shows outstanding effects on the microstructures and flow stress behavior of the billets. The billets with the specific casting process (I = 68 A, V = 65 mm/min) exhibit uniform microstructures and good deformation uniformity.