Some test results on the effect of SF6 decomposition products on superficial properties of epoxy resin compositions

Changes of the superficial properties of epoxy resin compositions with Al₂O₃ and SiO₂ fillers were investigated in dry SF₆ decomposed under the effect of the electric arc. The influence of electrode material, of small moisture and air content as well as of the presence in the test space of materials containing silicon upon the change of superficial resistivity and the structure of superficial strata and powders deposited on the surface of materials, is examined. It has been stated that the appearance of the minimum resistivity is bound with the formation of a superficial film containing mainly compounds of tungsten disengaged from the electrode material. The presence of silicon has a considerable effect on resistivity.