SiC/SiO<sub>2</sub> filler reinforced EP composite with excellent nonlinear conductivity and high breakdown strength
Qingguo Chi, Shuang Cui, T. D. Zhang, Meng Yang, Q. G. Chen
Abstract
In this paper, silicon carbide/silicon dioxide (SiC/SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ) filler with core/shell structure, as a filler in epoxy resin (EP), is studied. The effect of the thickness of the SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> shell is studied as it affects the microstructure and electrical properties of the SiC/SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> /EP composites at various temperatures. Compared with SiC/EP composites, the SiC/SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> /EP composites show outstanding electrical properties. The nonlinear coefficient of the 4 nm-SiC/SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> /EP composites increases from 2.88 (5 wt% SiC/EP) to 3.79, and the breakdown field strength increases 1.23 times. With increasing temperature, the electrical conductivity increases and the threshold field strength decreases. Moreover, as the SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> shell thickness increases, the breakdown field strength of the composite increases, and shows a weaker temperature dependence.