Of Mg-sm-x (x = Al And Zn In) Phase Diagram Alloying

Magnesium alloys have been attracting many attentions in recent years due to their properties such as low density, high specific strength, good castability, etc. Rare earths (RE), as an important class of alloying elements to magnesium-based alloys, are often added in Mg matrix to enhance the high temperature properties, corrosion-resistance and casting characteristics of the alloys. To improve our understanding about the precipitating process and design alloys composition, knowledge of phase diagrams and thermodynamic data of the involved systems are crucially necessary.In this work, the CALPHAD method have been used to optimize the Mg-Sm, Al-Sm and Sm-Zn systems, and the database of Mg-Al-Sm and Mg-Sm -Zn systems have been establish togather with the published parameters of the Mg-Al and Mg-Zn systems:1. Using CALPHAD method, the Mg-Sm and Al-Sm binary systems were optimized. Ordinary substitutional solution are adopted to model liquid, bcc and fcc terminal solution, and all intermetallic phases are treated as stoichiometric compounds. Calculated phase diagram and thermodynamic data are both consistent with experimental work.2. Using CALPHAD method, the Sm-Zn binary system was optimized. Ordinary substitutional solution model are employed to describe liquid, bcc and fcc phases, and all intermetallic phases are treated as stoichiometric phases. Calculated results are well consistent with that of experimental.3. The Mg-Al-Sm and Mg-Sm-Zn systems were extrapolated by integrating Mg-Sm, Al-Sm, Sm-Zn, Mg-Al and Mg-Zn binary systems, and liquids project and isothermal sections were calculated.