Tribological and electrical properties of TiO₂ thin films for polymer insulator as the dielectric coating of electric railroad

TiO₂ thin films were deposited on glass and polymer insulator substrates as self-cleaning coatings. TiO₂ films were deposited at various RF powers by the unbalanced RF magnetron sputtering method using a TiO₂ ceramic target. We investigated the tribological, structural, and electrical properties of the deposited TiO₂ films at various RF powers. The result showed that the hardness and elastic modulus values of the TiO₂ films increased with the increase of RF power. The surface roughness and contact angle values also increased with the increase of RF power. Also, the rms leakage currents of the TiO₂ films were low for the insulator coating layer. The TiO₂ films fabricated in this work are suitable for the protection of polymer insulators because of their low leakage current and good tribological properties.