Mechanism on improved surface flashover performances in vacuum of epoxy resin using fluorocarbon plasma treatment

Abstract

To improve the insulation, strength of materials is a permanent topic in the fields of high voltage and insulation, and surface insulation is one of the difficulties. Research shows that the surface fluorination by a non-equilibrium plasma is a promising method to enhance the surface flashover characteristics of insulating materials. However, the determinants of flashover characteristics are so many that the mechanism is not well known. This paper aims to find out the reasons for the surface insulation improvement and optimise the plasma process parameters. The epoxy resin surfaces are modified by a fluorocarbon plasma, and the flashover voltages in vacuum and secondary electron emission yield are tested experimentally. Combined with the state of the art and the authors' previous work, the mechanism of improved surface flashover performances is investigated in depth from three aspects: the plasma process parameters, the surface physical and chemical properties and the surface electrical performances. A comprehensive understanding of the mechanism is concluded, of which the whole processes from the plasma surface modification of materials to the surface insulation performances are taken into account. It is hopeful to promote the practical applications of plasma fluorination in electrical engineering through the findings of this paper.