Thermodynamic modeling and experimental investigation of the magnesium–zinc–samarium alloys

• Ternary phases in Mg–Zn–Sm alloy system were experimentally determined.
• One previously-reported ternary phase is determined as Mg3Sm binary phase.
• Phase relationships of Mg–Zn–Sm system near Mg corner are obtained experimentally.
• A thermodynamic description of this system was developed using CALPHAD method.

Magnesium (Mg)–Zinc (Zn)–Samarium (Sm) alloy system is being considered for the development of high-strength novel Mg alloys for structural applications. In this work, ternary phases in Mg–Zn–Sm system at Mg-rich corner were identified experimentally, based upon the investigation of five key alloys. Phase relationships at 350, 400 and 450 °C of this system were also established. Furthermore, a self-consistent thermodynamic description of Mg–Zn–Sm system at Mg-rich corner was developed for the first time using the CALPHAD (CALculation of PHAse Diagram) method. Good agreement between the calculated phase diagrams and the experimentally measured data from both this study and literature validated the thermodynamic modeling approach used in this work.