Advanced layer material constitution

Abstract

The increasing knowledge and understanding of the interrelations between the constitution, microstructure and properties of materials are the basis for the development of so-called advanced materials. In particular, ceramic bulk materials, metastable structures and special coatings for various applications are material groups of high interest. The background for developments in these areas is the constitution of multicomponent systems and the adjustment of special microstructures. Critical assessments and compilations of phase diagrams, the so-called maps of materials, are undertaken with strong emphasis worldwide. In many cases, however, the conditions employed in low temperature coating techniques do not allow the formation of equilibrium phases. Metastable structures and amorphous solid solutions are frequently observed. These are frozen in up to temperatures of about 0.3 T m (where T m is the melting temperature). As a consequence new metastable materials can be used in hard material coating systems (melting points of about 2500–3300°C) up to 700–1000°C. The possibility of predicting the constitution of multicomponent layer materials is a subject of special interest. This would support finally a specific layer material development. It should be pointed out that the ideas discussed are not restricted to hard coatings but have to be considered for all kinds of functional coatings.