The Preparation of Combined Aluminium Oxide Coatings on Aluminium Substrate

T h e prepara t ion and propert ies of combined a luminium oxide coatings have been investigated. T h e coating has been prepared in two steps. First , a luminium subs t ra te was anodically oxidized. In t he next s tep the anodized film has been coated by the sol-gel method . T h e condit ions of forming coatings wi thout shrinkage were obta ined empirically. It was found out t h a t the film prepared by the sol-gel me thod has the same crystal s t ruc ture as the oxide film prepared by the anodic oxidation. T h e thickness, phase analysis, and surface micros t ructure of obta ined coatings were determined.»-