Titanium and zirconium hard coatings on glass substrates prepared by the sol-gel method

摘要

In this work innovative antiscratch sol-gel coating films deposited on a soda-lime glass substrate are examined. Sol-gel coatings of different composition (TiO_2, TiO_2/B_2O_3, ZrO_2 and ZrO_2/B_2O_3) were prepared starting from Titanium, Zirconium and Boron alkoxides and from boron oxide. Coatings were obtained at room temperature and at atmospheric pressure by dip-coating using common soda lime silicate glass slides as substrates. Densification was carried out at 550 ℃ for 2 h in air. The morphology of the coatings has been studied by Atomic Force Microscopy, Scanning Electron Microscopy, and with a profilometer. Roughness grows with thickness and with boron addition. The mechanical properties of the films were evaluated by micro scratch at fixed and variable load. The scratch hardness numbers of ZrO_2 and ZrO_2/B_2O_3 coatings reach 6 GPa (glass value = 1.9 GPa), whereas the best value for the critical load is 16.7 N (glass value = 9 N).