Interfacial reaction and thermoelectric properties of Ca3Co4O9 ceramic diffusion bonding joints with different electrode intermediate layers. Issue 6 (15th March 2022)

• Record Type: Journal Article
• Authors: Chen, Haiyan; Zhao, Shuai; Zhang, Can; Shi, Zongmo; Gao, Feng; Wang, Qian; Shen, Zhikang; Li, Wenya
• Is Part Of: Ceramics international. Volume 48:Issue 6(2022)
• Page Start: 8540
• Page End: 8547
• Publication Date: 2022-03-15
• Subjects: Ca3Co4O9 -- Thermoelectric material -- Electrode joint -- Diffusion bonding -- Interfacial microstructure; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2021.12.064
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: p-Ca3 Co4 O9 ceramic and Al2 O3 substrate were welded by vacuum diffusion bonding via different interlayers. Metal oxides could be observed at the interface when copper foil and nickel foil were applied. There was no obvious reaction layer at the interface when silver foil was applied. In the diffusion bonding process, Ca3 Co4 O9 thermoelectric ceramic decomposed into CaO and CoO. CaO and CoO reacted again to form Ca3 Co4 O9 after oxygen enriched treatment at 850 °C for 10 h. The joints fabricated using silver foil exhibited the highest shear strength of 10.8 MPa. The electrical resistivity of p-type Ca3 Co4 O9 ceramic was 44.57 mΩ cm, Seebeck coefficient was 192.08 μV/K and the power factor was 0.08 mW m −1 K −2 at 800 °C. Moreover, a maximum power factor of 0.21 mW m −1 K −2 was obtained at the temperature of 500 °C. The resistance of the module was approximately 3.92 Ω, which is 60% lower than that of the unheated module.