Enhancement of surface insulation properties of alumina/epoxy composites through ZrO₂ film sprayed by plasma atomization

Abstract Alumina/epoxy composites are widely used in the manufacture of basin insulators, but their surfaces tend to accumulate charges under the high‐voltage direct current (HVDC), which induce the decline of surface insulating property. In this article, the modification method of depositing ZrO₂ film sprayed by plasma atomization was proposed to improve the surface insulation performance of the material. Argon was used as the plasma discharge gas, and ZrO (NO₃)₂.xH₂O was used as the zirconium source. The morphology, surface roughness and the element content of materials were measured, and the surface conductivity, flashover voltage, and charge characteristics of the treated samples were tested. The experimental results displayed that a zirconia film was formed on the epoxy resin surface, which restrain the accumulation of surface charges. The surface conductivity of the modified sample was improved by 3 to 4 orders of magnitude, and the flashover voltage was increased by 20%. Studies have shown that: ZrO₂ film sprayed by plasma atomization can improve the insulation performance of epoxy resin surface, and it provides an effective method for the surface modification of insulating materials.