Relationship between microstructure evolution and thermal conductivity of Mg-Sn-Ca alloys

作者：Zhou, Xiong; Luo, Gan; Mo, Liling; Du, Jun^*

来源：Journal of Materials Research, 2022, 37(21): 3720-3730.

DOI：10.1557/s43578-022-00746-4

• Microstructure evolution
• Thermal conductivity
• Mg-Sn-Ca alloy
• Thermal analysis
• Sn-rich region

The relationship between microstructure evolution and thermal conductivity of the Mg-Sn-Ca alloys with various contents was investigated. The microstructures of Mg-2Sn-xCa alloys showed significant changes with different Ca contents. The addition of Ca can effectively improve the thermal conductivity of Mg-2Sn alloy. The thermal conductivity was remarkably improved to 147 W/(m center dot K) when the Sn/Ca atomic ratio was 1:1. The significant increase owes to the consumption of solute atoms and elimination of high-resistance Sn-rich regions. Mg-Sn-Ca alloys with Sn/Ca atomic ratio of 1 exhibited different solidification behaviors as the content increased. The thermal conductivity decreased linearly when the Sn content was below 3 wt% and then decreased rapidly at Sn content above 3 wt%. The former was dominated by the precipitated phase, while the latter was caused by Sn-enriched regions with high resistance.