Technological Problems in Fabrication of Mg-Based Thermoelectric Materials by Conventional Casting Methods |
| A. Gryc, M. Malczewska, T. Rzychoń, A. Kiełbus
Institute of Materials Engineering, Silesian University of Technology, Politechnika Śląska, Z. Krasińskiego 8, 40-019 Katowice, Poland |
| Received: August 26, 2019; in final form February 25, 2020 |
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| In the paper the potential of conventional casting technology in fabrication of modern magnesium-based thermoelectric materials was evaluated. Although these materials are considered as potential environmental-friendly alternative for commercially used thermoelectric materials based on heavy metals, fabrication of bulk Mg-based thermoelectric materials with simple and cost-effective technologies is still challenging. In the present work it was found that it is possible to obtain Mg-based thermoelectric materials with conventional gravity casting technology. The following technological problems were identified: high reactivity and vapor pressure of magnesium, large difference in melting point and density of the components, high fragility, high synthesis temperature and significant solidification volume shrinkage. The application of solutions and adjustments to the conventional gravity casting method, comprising the usage of non-reactive crucible and mold materials, inert atmosphere of argon, intensive mechanical stirring, and decrease of cooling rate of solidifying ingots led to fabrication of relatively pure (98%) bulk Mg2Sn thermoelectric compound. |
DOI:10.12693/APhysPolA.137.1050 topics: thermoelectric materials, magnesium, casting, technological problems, process design |