@article{Wang2025, 
author = {Xinyu Wang and Jiawang He and Yongjun Li and Yongsen Han},
title = {Effects of SiC@Al2O3 Nanoparticles on the Nonlinear Conductivity of Epoxy Composites},
year = {2025},
journal = {Chinese Journal of Electrical Engineering},
volume = {11},
number = {3},
pages = {29-37},
keywords = {Core-shell structure, nanocomposite, SiC, nonlinear conductivity, breakdown strength},
url = {https://www.sciopen.com/article/10.23919/CJEE.2025.000170},
doi = {10.23919/CJEE.2025.000170},
abstract = {Nonlinear conductivity enables an insulating material to self-homogenize its electric field distribution, which can be regulated by the core-shell method. In this study, the effects of SiC@Al2O3 on nonlinear conductivity are investigated. First, SiC@Al2O3 nanoparticles are fabricated. Subsequently, 3 wt%, 7 wt%, and 10 wt% SiC@Al2O3/epoxy and SiC/epoxy composites are prepared. The microstructures of the SiC@Al2O3 nanoparticles are characterized using transmission electron microscopy, scanning electron microscopy, and X-ray diffraction. The dielectric spectra, breakdown strengths, and conductivities of the epoxy composites are investigated. The experimental results show that a 2-nm-thickness Al2O3 shell is formed around the SiC nanoparticles. Compared with the raw SiC nanoparticles, the SiC@Al2O3 nanoparticles not only reduced the relative permittivity and loss tangent of the composite but also enhanced its breakdown strength. All of the SiC/epoxy composites exhibited nonlinear conductivity, whereas only the 7 wt% and 10 wt% SiC@Al2O3/epoxy composites exhibited nonlinear conductivity. Moreover, the SiC@Al2O3/epoxy composites had a higher switching electric field (i.e., the initial electric field for nonlinear conductivity) than the SiC/epoxy composites. The results demonstrate the possibility of using nonlinear resistive field grading material in high-electric-field applications.}
}