Effect of solute atoms and second phases on the thermal conductivity of Mg-RE alloys: A quantitative study

In this study, the room temperature thermal conductivity and microstructure of Mg−Ce, Mg−Sm and Mg−Y binary alloys in as-cast and solution treated conditions were investigated. Quantitative study was conducted on the effect of rare earth elements (in solid solution and intermetallic compounds) on the thermal conductivity of Mg−RE alloys. The reduction in thermal conductivity was determined to be about 123.0 W/(m·K) and 6.5-16.4 W/(m·K), respectively, per 1 at.% RE addition in the form of solid solution or intermetallic compounds with Mg. The thermal conductivities of Mg−RE alloys were fitted using modified Maxwell and EMT models based on the distribution, volume fractions and shape of intermetallic compounds. The modified structural models provide a good fit to the experimental thermal conductivity data.