Effects of isothermal homogenization on microstructure evolution of Mg-7Gd-5Y-1MM-0.5Zr alloy

Optical microscopy(OM), scanning electronic microscopy(SEM) and X-ray diffraction(XRD) were performed to investigate the influence of homogenization on the microstructures of the Mg-7Gd-5Y-1MM(Ce-rich RE)-0.5Zr magnesium alloy. The results indicated that α-Mg, Mg24(Gd Y)5 phase, Mg5(Gd Y) phase and Mg12 MM phase coexisted together in as-cast alloy; the microstructures were largely characterized by α-Mg matrix and gray globular or elliptic ball Mg12 MM phase, in addition to those with cubic block Mg24(Gd Y)5 phase after homogenization; the reasonable homogenization regime was maintained at 530 oC for 32 h.