Experimental investigation and thermodynamic modeling of the Mg-Sn-Sr ternary system

摘要

The isothermal sections of the Mg-Sn-Sr ternary system in the Mg-rich region at 415 and 350 degrees C have been determined using the scanning electron microscopy (SEM) equipped with energy dispersive X-Ray spectrometry (EDS). The existence of the MgSnSr ternary compound was confirmed in these two isothermal sections. Two new compounds, named Mg5Sn3Sr and Mg25Sn24Sr14, were found in the present work based on the SEM/EDS results. Thermodynamic optimization of the Sn-Sr binary and Mg-Sn-Sr ternary systems were carried out using the CALPHAD (CALculation of PHAse Diagrams) technique. The Modified quasi-chemical model (MQM) was used for the liquid solution which exhibits a high degree of short-range ordering behavior. The solid phases were described with the Compound energy formalism (CEF). Finally, a self-consistent thermodynamic databases for the Mg-Sn-Sr ternary system has been constructed in the present work, which can be an efficient and convenient guidance to investigate and develop the Mg-based alloys.