Multilayer coatings preparation of zirconia-based by sol-gel route; microstructural and mechanical characterisation

Frequently, the total substitution of a specific material for a certain app lication can be avoided by improving their surface properties (resistance t o erosion and corrosion, electric Properties, etc.). In particular, surface protection with ceramic coatings can be the solution of many practical pro blems, For this reason, the development of new ceramics coatings is a resea rch area of technological interest. Sol-gel is a very interesting route to Obtain oxide thin films on different substrates. In this work, our interest is centred on the protection of metallic substrates by using sol-gel zirco nia coatings. The precursor sol-gel solution was obtained by hydrolysis of zirconium n-propoxide in propanol and nitric acid. We developed a routine f abrication of free cracks multilayer dip-coatings, with total thickness in the range 200-3000 nm. A microstructural and mechanical characterisation, b y using Berkovich ultramicrohardness tests, will be presented.