About this Abstract |
Meeting |
2024 TMS Annual Meeting & Exhibition
|
Symposium
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Alloys and Compounds for Thermoelectric and Solar Cell Applications XII
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Presentation Title |
Characterization of Composition Gradient Layered Microstructure Formed in Mg2(Si, Sn)-based Thermoelectric Alloys |
Author(s) |
Yoshisato Kimura, Hiromasa Ichise, Feifan Zhang, Yaw Wang Chai, Manabu Watanabe, Yonghoon Lee |
On-Site Speaker (Planned) |
Yoshisato Kimura |
Abstract Scope |
Composition gradient layered microstructure (CGLM) formation in Mg2(Si,Sn) alloys during solidification process was reported by the authors group. CGLM consists of Mg2(Si,Sn) solid solution several layers with gradient Si/Sn ratio. The first layer is Si-rich Mg2(Si,Sn) primary crystal and the last layer is Sn-rich Mg2(Si,Sn) formed by the peritectic reaction. Microstructure analysis using TEM revealed that each layer consists of several tens of nm grains having different Si/Sn ratio. CGLM morphology was characterized by Si/Sn ratio distribution using an X-ray diffraction peak, i.e., 2θ positions spreading in several degrees correspond to various Si/Sn ratio and peak intensity indicates volume fraction. Fully CGLM having wide Si/Sn ratio was fabricated by optimizing process condition to suppress nonequilibrium Si and Sn phases. Thermal conductivity can effectively be reduced in fully CGLM, compared with CGLM coexisting with Si and Sn, due to remarkable solid solution effect and high density interfacial dislocations. |
Proceedings Inclusion? |
Planned: |
Keywords |
Electronic Materials, Solidification, Characterization |