Preparation and nonlinear conductivity modification of doped ZnO/EP composite materials

Spacecraft is running on the GEO (geostationary orbit), the high energy electrons irradiation will cause spacecraft surface charging and deep dielectrics charging, because of high resistivity of dielectrics, the accumulated charges were hard to be released timely, this seriously affects the normal operation for spacecraft. In the present work, the modification was adopted by adding ZnO micro-powder to the epoxy based resin, and resulting new kinds of modified ZnO/EP composite materials (1%, 3%, 5%) with different ZnO mass fraction. Conductivity test and breakdown test were been done for the modified ZnO/EP composite materials, the conductivity results showed that current density of 1% modified ZnO/EP is maximum and minimum for 5% modified ZnO/EP under the same electric-field condition; When electric-field is more than 20 kV/mm, current density of all modified ZnO/EP can increase exponentially with the electric-field increasing. Moreover, the DC breakdown results showed that the breakdown strength of modified ZnO/EP can still keep a same level compared to the pure EP, and 1% modified ZnO/EP has a highest DC breakdown strength.