Phase characterization and properties regulation of Mg-4Sn-La-Ca alloy

Authors：Zhou, Xiong; Mo, Liling; Du, Jun^*

Source：Materials Characterization, 2022, 194: 112274.

DOI：10.1016/j.matchar.2022.112274

• Ultrasonic treatment
• Heat treatment
• (LaCa)MgSn phase
• Thermal conductivity
• Mechanical properties

Mg-4Sn-2.3La-0.68Ca alloy with equal atomic ratio of Sn/(La + Ca) was designed. The microstructure was regulated by ultrasonic treatment and heat treatment. The effects of different treatments on the thermal con-ductivity and mechanical properties of the alloy were studied. The dissolution of Ca converts the LaMgSn phase to form the (La,Ca)MgSn phase, in which crystal structure was determined. Ultrasonic treatment refines both primary and eutectic phases and simultaneously improves of thermal conductivity and mechanical properties. Heat treatment modifies the eutectic morphology and further enhances the thermal conductivity of the alloy. The thermal conductivity of the alloy reached 145 W/(m center dot K) after ultrasonic and heat treatment. A modified model was used to establish the relationship between microstructure and thermal conductivity. It well evaluates the variation of thermal conductivity after different treatment processes.