Measurements of diffusion coefficients of Ce, Gd and Mn in Mg

Easy-to-use liquid-solid diffusion couples (LSDCs) were employed to measure the diffusion coefficients of three key alloying elements Ce, Gd and Mn in Mg at elevated temperatures. Forward simulation analysis was then performed on the concentration profiles measured from LSDCs using EPMA to extract diffusion coefficients at multiple temperatures. The new experimental data were combined with limited experimental data in the literature to establish reliable diffusion coefficient datasets which are then compared with first principles calculation results. It is concluded that Ce diffuses faster than Gd in Mg while Mn is the slowest diffusing element among the three. The interdiffusion coefficients of Mg-Ce, Mg-Gd and Mg-Mn are also determined for the first time. The current study and our previous studies together have determined reliable impurity diffusion coefficients of 8 elements Al, Ca, Ce, Gd, Mn, Sn, Zn, and Y in Mg; and the results are summarized and compared.