Electrical conductivity and infrared radiation performance of SiC-CNT composite ceramics. Issue 11 (September 2023)

• Record Type: Journal Article
• Authors: Zhu, Ming; Chen, Jian; Li, Fanfan; Huang, Changcong; Liu, Huan; Liu, Xuejian; Huang, Zhengren
• Is Part Of: Journal of the European Ceramic Society. Volume 43:Issue 11(2023)
• Page Start: 4627
• Page End: 4635
• Publication Date: 2023-09
• Subjects: SiC-CNT composite ceramics -- Schottky barrier -- Grain boundary -- Electrical percolation -- Infrared emissivity; Ceramic materials -- Periodicals; Composite materials -- Periodicals; Matériaux céramiques -- Périodiques; Composites -- Périodiques; Ceramic materials; Composite materials; Periodicals; Electronic journals; 666.05
• DOI: 10.1016/j.jeurceramsoc.2023.04.045
• Languages: English
• ISSNs: 0955-2219

Abstract

Abstract: SiC ceramic is an excellent infrared source material that can be used in a wide range of fields, like infrared heating, night vision and communication, but its poor electrical properties limit it. In this work, carbon nanotubes (CNTs) were selected as conductive phase filler, and SiC-CNT composite ceramics were prepared by SPS method. The effects of CNT content on the microstructures, electrical properties and infrared radiation performance of the composites were studied. The introduction of CNT effectively reduced the height of Schottky barrier at grain boundary, thus weakening the grain boundary effect, reducing the grain boundary resistance, further weakening the nonlinear characteristics and bulk resistivity of the composite ceramics. When the content of CNT was 1 wt%, electrical percolation was achieved, and the bulk resistivity of SiC ceramics dropped by nearly 3 orders of magnitude. The preferred orientation distribution of CNT made the bulk resistivity perpendicular to the pressure direction R⊥ always lower than that parallel to the pressure direction R// . The sample with 5 wt% CNT assumed linear conductivity characteristics, with bulk resistivity in different direction of 16.5 Ω cm (R// ) and 11.8 Ω cm (R⊥ ), respectively. CNT addition slightly increased the infrared radiation performance of SiC ceramics, and the sample with 5 wt% CNT possessed the highest total emissivity of 0.675. The excellent electrical conductivity and infrared radiation performance of SiC-CNT composite ceramic confirmed this class as a promising infrared source material.