| About this Abstract |
| Meeting |
2023 TMS Annual Meeting & Exhibition
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| Symposium
|
Alloys and Compounds for Thermoelectric and Solar Cell Applications XI
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| Presentation Title |
Effects of Doping Element Addition on Phase Equilibria and Mg2Si–Mg2Sn Two-phase Microstructure Formation in Thermoelectric Mg2(Si, Sn)-based Alloys |
| Author(s) |
Yoshisato Kimura, Naoki Ueda, Yaw Wang Chai, Manabu Watanabe, Yonghoon Lee |
| On-Site Speaker (Planned) |
Yoshisato Kimura |
| Abstract Scope |
Formation of solid solution Mg2(Si,Sn) is a dominant factor to effectively reduce the thermal conductivity, while introducing the phase interfaces according to the Mg2Si–Mg2Sn two-phase separation based on large lattice misfit can be an additional factor. The objective of the present work is to evaluate and to understand the effects of typical doping elements addition, n-type Al and p-type Ag, on the phase equilibria, two-phase Mg2Si–Mg2Sn microstructure formation, and thermoelectric properties. Since the solubility of Al is negligible small in both Mg2Si and Mg2Sn phases, solidification microstructure during furnace cooling after the induction heat melting is hardly affected by the Al addition. Contrary to this, Ag is preferably partitioned and soluble in the Mg2Sn phase with a small amount but in the Mg2Si phase, which causes drastic change of solidification path and resulting in Mg2Si phase grains coarsening, which is unfavorable to reduce thermal conductivity. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Electronic Materials, Solidification, |