Contribution to the percolation threshold study of Silicon Carbide filled polydimethylsiloxane composites used for field grading application

Abstract

Abstract Nonlinear V-I characteristics of particulate composite prepared from dispersion of silicon carbide in a siloxane elastomer have been measured as a function of filler concentration up to the maximum allowable of about 32 vol.%. Two critical concentrations (percolation thresholds) are obtained at volume fractions of about 17 and 24 vol.% for low and high electric fields. These values are consistent with the critical concentrations predicted by the theory: 14 and 31 vol.% respectively and may come from edge and face contacts between SiC semi-conducting particles.