Novel corrosion resistant hard-coatings for metal surfaces

Abstract

Using the sol-gel process, novel inorganic-organic composites (Ormocers) were synthesized. BY controlled hydrolysis and condensation of an epoxy modified alkoxide, a propyl modified alkoxide and an aluminum alkoxide in the presence of fluoride ions, stable sols can be produced. Theses can be applied by conventional coating techniques (e.g. spray-, spin-, dip-coating) on metal surfaces (Al, Zn, Mg) and cured thermally. The high corrosion inhibitant properties are explained by a special metal/coating interface. The transparent coatings show good adhesion, corrosion protection and a high wear resistance avoiding chemical pretreatment (e. g. chromating). These new coatings open a wide field of applications.