Microstructure investigations of directionally solidified Mg-rich alloys containing Al, Ca and Sn

The thermodynamic description of Mg–Al–Ca–Sn quaternary system in the Mg-rich region was developed on the basis of both our previous work and literature data on the key constituent ternaries, including Mg–Al–Ca, Mg–Al–Sn and Mg–Ca–Sn systems. Using this description coupled with the Scheil model, the solidification paths of Mg–Ca–Sn ternary alloys and Mg–Al–Ca–Sn quaternary alloys were calculated, which are in good accordance with the experimental results from directional solidification obtained by us.