Effect of Sn on thermal conductivity of Mg-5Zn based alloys

For the enhancement of high temperature performance of the Mg-Zn based alloys, Sn element has been alloyed. However, the effect of Sn on the thermal conductivity of the Mg-Zn based alloys has been barely studied. In this study, pure Mg and Mg-5Zn alloys are alloyed with a 1, 3, and 5 mass% of Sn, respectively, and the heat capacity, thermal diffusivity and thermal conductivity of the alloys are then evaluated in a temperature range of 298 to 573 K. In the Mg-Sn binary alloys, the heat capacity and thermal diffusivity gradually decrease with increasing the volume fraction of the Mg₂Sn phase. In the Mg-Zn-Sn based alloys (ZT alloy), since the adding Sn element is mostly located at the MgZn₂ phases, thermal diffusivity is not affected with an increment of Sn content. Furthermore, the thermal conductivity of the ZT55 alloy at elevated temperatures is slightly higher than that of the ZT53 alloys.