The principle of combining different materials in order to utilize their inherent qualities within the single final material/piece is rapidly finding its way to engineering practice. Advances in processing technology have made it possible to mimic the approach used by nature to design structures such as shells and teeth with a layered architecture. Within the group of layered ceramics, one can distinguish ceramic coatings, ceramic multi-layers, and functionally graded ceramics. With respect to their mechanic al properties, these groups of heterogeneous materials have the common characteristic that the local properties vary through their thickness.
Many of the mechanical reliability problems encountered in multi-layered materials are linked to the abrupt change of material properties at the border between dissimilar layers. These problems are potentially solved using the novel concept of functionally graded materials (FGMs), in which the transition between micro-structurally or chemically dissimilar materials is realised in a continuous manner. The main goal of the present project is to contribute to fundamental understanding of microstructure and mechanical properties of layered ceramic composites and coatings in terms of the distribution and individual properties of constituent layers and interfaces, and thus to help to assess existing methods and to develop new methods of the quantitative characterisation of reliability of these materials. This will be achieved through a combination of simulations, experiments, micro- and substructure studies, and analyses based upon the principles of fracture mechanics, mechanics of materials and materials science.