Metallization and Diffusion Bonding of CoSb<sub>3</sub>-Based Thermoelectric Materials

CoSb<sub>3</sub>-based skutterudite alloy is one of the most promising thermoelectric materials in the middle temperature range (room temperature&#8212;550 &#176;C). However, the realization of an appropriate metallization layer directly on the sintered skutterudite pellet is ind...

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Main Authors: Hangbin Feng, Lixia Zhang, Jialun Zhang, Wenqin Gou, Sujuan Zhong, Guanxing Zhang, Huiyuan Geng, Jicai Feng
Format: Article
Language:English
Published: MDPI AG 2020-03-01
Series:Materials
Subjects:
Online Access:https://www.mdpi.com/1996-1944/13/5/1130
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spelling doaj-3e41b16b20654fd0a70d906e83f464d62020-11-25T00:42:31ZengMDPI AGMaterials1996-19442020-03-01135113010.3390/ma13051130ma13051130Metallization and Diffusion Bonding of CoSb<sub>3</sub>-Based Thermoelectric MaterialsHangbin Feng0Lixia Zhang1Jialun Zhang2Wenqin Gou3Sujuan Zhong4Guanxing Zhang5Huiyuan Geng6Jicai Feng7State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001, ChinaState Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001, ChinaState Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001, ChinaState Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001, ChinaZhengzhou Research Institute of Mechanical Engineering, Zhengzhou 450001, ChinaZhengzhou Research Institute of Mechanical Engineering, Zhengzhou 450001, ChinaState Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001, ChinaState Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001, ChinaCoSb<sub>3</sub>-based skutterudite alloy is one of the most promising thermoelectric materials in the middle temperature range (room temperature&#8212;550 &#176;C). However, the realization of an appropriate metallization layer directly on the sintered skutterudite pellet is indispensable for the real thermoelectric generation application. Here, we report an approach to prepare the metallization layer and the subsequent diffusion bonding method for the high-performance multi-filled <i>n</i>-type skutterudite alloys. Using the electroplating followed by low-temperature annealing approaches, we successfully fabricated a Co-Mo metallization layer on the surface of the skutterudite alloy. The coefficient of thermal expansion of the electroplated layer was optimized by changing its chemical composition, which can be controlled by the electroplating temperature, current and the concentration of the Mo ions in the solution. We then joined the metallized skutterudite leg to the Cu-Mo electrode using a diffusion bonding method performed at 600 &#176;C and 1 MPa for 10 min. The Co-Mo/skutterudite interfaces exhibit extremely low specific contact resistivity of 1.41 &#956;Ω cm<sup>2</sup>. The metallization layer inhibited the elemental inter-diffusion to less than 11 &#181;m after annealing at 550 &#176;C for 60 h, indicating a good thermal stability. The current results pave the way for the large-scale fabrication of CoSb<sub>3</sub>-based thermoelectric modules.https://www.mdpi.com/1996-1944/13/5/1130thermoelectric materialsjoiningskutterudite alloyco-mo metallization layer
collection DOAJ
language English
format Article
sources DOAJ
author Hangbin Feng
Lixia Zhang
Jialun Zhang
Wenqin Gou
Sujuan Zhong
Guanxing Zhang
Huiyuan Geng
Jicai Feng
spellingShingle Hangbin Feng
Lixia Zhang
Jialun Zhang
Wenqin Gou
Sujuan Zhong
Guanxing Zhang
Huiyuan Geng
Jicai Feng
Metallization and Diffusion Bonding of CoSb<sub>3</sub>-Based Thermoelectric Materials
Materials
thermoelectric materials
joining
skutterudite alloy
co-mo metallization layer
author_facet Hangbin Feng
Lixia Zhang
Jialun Zhang
Wenqin Gou
Sujuan Zhong
Guanxing Zhang
Huiyuan Geng
Jicai Feng
author_sort Hangbin Feng
title Metallization and Diffusion Bonding of CoSb<sub>3</sub>-Based Thermoelectric Materials
title_short Metallization and Diffusion Bonding of CoSb<sub>3</sub>-Based Thermoelectric Materials
title_full Metallization and Diffusion Bonding of CoSb<sub>3</sub>-Based Thermoelectric Materials
title_fullStr Metallization and Diffusion Bonding of CoSb<sub>3</sub>-Based Thermoelectric Materials
title_full_unstemmed Metallization and Diffusion Bonding of CoSb<sub>3</sub>-Based Thermoelectric Materials
title_sort metallization and diffusion bonding of cosb<sub>3</sub>-based thermoelectric materials
publisher MDPI AG
series Materials
issn 1996-1944
publishDate 2020-03-01
description CoSb<sub>3</sub>-based skutterudite alloy is one of the most promising thermoelectric materials in the middle temperature range (room temperature&#8212;550 &#176;C). However, the realization of an appropriate metallization layer directly on the sintered skutterudite pellet is indispensable for the real thermoelectric generation application. Here, we report an approach to prepare the metallization layer and the subsequent diffusion bonding method for the high-performance multi-filled <i>n</i>-type skutterudite alloys. Using the electroplating followed by low-temperature annealing approaches, we successfully fabricated a Co-Mo metallization layer on the surface of the skutterudite alloy. The coefficient of thermal expansion of the electroplated layer was optimized by changing its chemical composition, which can be controlled by the electroplating temperature, current and the concentration of the Mo ions in the solution. We then joined the metallized skutterudite leg to the Cu-Mo electrode using a diffusion bonding method performed at 600 &#176;C and 1 MPa for 10 min. The Co-Mo/skutterudite interfaces exhibit extremely low specific contact resistivity of 1.41 &#956;Ω cm<sup>2</sup>. The metallization layer inhibited the elemental inter-diffusion to less than 11 &#181;m after annealing at 550 &#176;C for 60 h, indicating a good thermal stability. The current results pave the way for the large-scale fabrication of CoSb<sub>3</sub>-based thermoelectric modules.
topic thermoelectric materials
joining
skutterudite alloy
co-mo metallization layer
url https://www.mdpi.com/1996-1944/13/5/1130
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