Synthesis kinetics of Mg2Sn in Mg-Sn powder mixture using non-isothermal differential scanning calorimetry

The non-isothermal heating process of Mg-Sn powder mixture was studied by differential scanning calorimetry(DSC) technique and the synthesis kinetics of Mg2Sn was evaluated by the model-free and model-fitting methods. The activation energy and conversion function of Mg2Sn synthesis reaction are calculated to be 281.7 kJ/mol and g(α)=[−ln(1−α)]1/4, respectively. The reaction mechanism of 2Mg+Sn→Mg2Sn under non-isothermal condition is regarded as “nucleation and growth”. During the non-isothermal heating process, the phase transformation occurred in the Mg-Sn powder mixture was analyzed by XRD and the microstructure evolution of Mg2Sn was observed by optical microscopy, which is in good agreement with the reaction mechanism of 2Mg+Sn→Mg2Sn deduced from the kinetic evaluation.