Improving the suppression of charge movement by porous chromium oxide coating.

A chromium trioxide coating was prepared on the surface of electronic ceramics by screen printing, and solid-phase sintering was carried out at 1350 °C. The surface roughness and surface resistance characteristics of composite coatings with different chromium trioxide contents were studied. The analysis results indicate that the average thickness of Cr 2 O 3 coating is about 19.89 μm. The main crystal phase is (Al 0.9 Cr 0.1) 2 O 3. SEM shows that the surface "pores" and surface roughness of the coating change with the content of Cr 2 O 3. AFM shows that when the Cr 2 O 3 content in the coating is 0.0921 mol, the surface roughness changes the most, and the corresponding surface resistivity of Al 2 O 3 insulating ceramics decreases to the lowest, from 1016 Ω to 1012 Ω. An increase in surface roughness can lead to changes in the incidence angle of electrons, reducing the probability of electron surface collision. The lower the surface resistivity, the better the high-voltage breakdown resistance of vacuum ceramic devices, thereby improving the surface flashover performance of ceramics. • The surface resistivity of Al 2 O 3 insulating ceramics decreases from 1016 Ω to 1012 Ω. • Chromium trioxide/ceramic composite coating was prepared with thickness about 19.89 μm. • An increase in surface roughness can lead to improve the surface flashover performance of ceramics. • The "pores" on the coating surface inhibit the movement of charge. [ABSTRACT FROM AUTHOR]