For improving insulating performance and modifying surface of insulating materials

the surface flashover properties and surface morphology of PTFE and PMMA before and after flashover were investigated experimentally using positive DC power supply at atmospheric pressure.Results show that the flashover voltage of the materials approximately obeys Weibull distribution

by which the flashover voltage of any possibility can be figured out.The surface morphology of the insulating materials were analyzed by 3D microscopy and atomic force microscopy

and results show that the discharge traces on the material surface are more evident in the vicinity of the cathode. In addition

some continuous ravines are observed on the material surface after flashover

and the surface roughness increases significantly.It is concluded that the flashover voltage is affected by the distortion of the electric field and the surface morphology of materials

which may provide reference to improving the insulating performance of polymer materials.