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

Abstract

Frequently, the total substitution of a specific material for a certain application can be avoided by improving their surface properties (resistance to erosion and corrosion, electric properties, etc.). In particular, surface protection with ceramic coatings can be the solution of many practical problems. For this reason, the development of new ceramics coatings is a research 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 zirconia coatings. The precursor sol-gel solution was obtained by hydrolysis of zirconium n-propoxide in propanol and nitric acid. We developed a routine fabrication of free cracks multilayer dip-coatings, with total thickness in the range 200-3000 nm. A microstructural and mechanical characterisation, by using Berkovich ultramicrohardness tests, will be presented.