Mg-Al-Ca 系合金の熱伝導率に及ぼす化学組成とミクロ組織の影響

In recent years, the increasing demand for electric vehicles, digital devices such as PCs and smartphones, and renewable energy storage systems has created a need for higher-performance batteries. Accordingly, the thermal conductivity of the case that houses the battery is becoming increasingly important. In this study, compositions with high thermal conductivity and good castability were investigated, focusing on Mg-Al-Ca alloys, and the relationship between the two was examined through thermal conductivity measurements and microstructural observations. As a result, the Mg-6%Al-4%Ca alloy was optimal in terms of castability and thermal conductivity. It was confirmed that a lower Al solid solution capacity and a higher purity of the matrix phase are important to improve the thermal conductivity. It is also suggested that the second phase, platelet Al₂Ca, is likely to be recognized and enriched in the matrix, contributing to the improvement of thermal conductivity. The amount of Ca solid solution in the matrix was suggested to be reduced by the enrichment of Al in the matrix. The Ca solid solution in the matrix was found to be less effective in reducing thermal conductivity than the Al solid solution.