DECORATIVE OPTICAL COATINGS

The paper gives a survey of current research on decorative coatings. I n the first part the main deposition techniques as well as characteriz ation techniques are discussed. The paper is restricted to decorative physically vapor deposited hard coatings with electrochemically deposi ted barrier coatings. The influence of stoichiometry, structure, and s urface roughness on the colour of physically vapor deposited hard coat ings is reviewed. In the last decades, a number of different coating d eposition techniques have been developed. The demand for environmental compatibility of low cost large-scale production techniques has resul ted in the development of combinations of physical vapor deposition an d electroplating. Coating systems have been developed using NiPd and C uSn(Zn) instead of Ni electroplated coatings as interlayers, strongly reducing the allergy risk. New industrial applications demonstrate the increasing economic importance of decorative hard coatings.