The reactive diffusion in Mg-Gd binary system was studied at 773 K by optical microscopy（OM）, scanning electron microscopy（SEM） and electron probe micro-analysis（EPMA）. After annealing at 773 K for 12-48 h, four...The reactive diffusion in Mg-Gd binary system was studied at 773 K by optical microscopy（OM）, scanning electron microscopy（SEM） and electron probe micro-analysis（EPMA）. After annealing at 773 K for 12-48 h, four different intermetallic layers, Mg5 Gd, Mg3 Gd, Mg2 Gd and Mg Gd, form at the Mg/Gd interfaces in the diffusion couples. The thicknesses of intermetallic layers δi（i stands for the phases of Mg5 Gd, Mg3 Gd, Mg2 Gd and Mg Gd, respectively） are proportional to the square root of annealing time t1/2, which indicates that the growth behavior of the intermetallics is controlled by the diffusion rate. The ratio of thickness of each intermetallic layer to the total thickness is constant with increasing the annealing time, which means that the growth behavior is constant at a certain annealing temperature. The diffusion coefficient of Gd in different intermetallics was calculated by Matano method.展开更多
基金Projects(2013CB6322022013CB632205)supported by the National Basic Research Program of China
文摘The reactive diffusion in Mg-Gd binary system was studied at 773 K by optical microscopy（OM）, scanning electron microscopy（SEM） and electron probe micro-analysis（EPMA）. After annealing at 773 K for 12-48 h, four different intermetallic layers, Mg5 Gd, Mg3 Gd, Mg2 Gd and Mg Gd, form at the Mg/Gd interfaces in the diffusion couples. The thicknesses of intermetallic layers δi（i stands for the phases of Mg5 Gd, Mg3 Gd, Mg2 Gd and Mg Gd, respectively） are proportional to the square root of annealing time t1/2, which indicates that the growth behavior of the intermetallics is controlled by the diffusion rate. The ratio of thickness of each intermetallic layer to the total thickness is constant with increasing the annealing time, which means that the growth behavior is constant at a certain annealing temperature. The diffusion coefficient of Gd in different intermetallics was calculated by Matano method.
