CORDIS - EU research results

Microstructure and properties of structural layered ceramics

Final Activity Report Summary - MAPSLAC (Microstructure and properties of structural layered ceramics)

The research topic of the project was to characterise the microstructure and study the mechanical properties of ceramic multilayered materials, mainly in the form of Functionally graded materials (FGM), and through better understanding of the microstructure and layered structure mechanical properties relationship to improve future design of these materials.

The microstructure, internal stress states and mechanical properties of alumina and zirconia functionally gradient materials prepared by electrophoretic deposition in the Catholic University of Leuven, Belgium, were investigated. The stresses built up due to thermal expansion mismatch between macroscopic layers were studied using spectroscopic and indentation methods. The role of gradient layers in suppressing the sharp, potentially hazardous, stress transitions was also explored. Given the limitations of the experimental methods, the internal stress states were explored theoretically by means of numerical and analytical studies. Furthermore, the influence of the residual stresses on the crack propagation and failure due to mechanical and thermal shock loading was studied. Based on the results the limits of the material design were defined.

The results up to the project completion showed that the hard surface of the experimental FGM, which was subject to compressive stresses, exhibited enhanced fracture toughness and wear resistance. This implied that, together with its potentially good corrosion and creep resistance, this sort of materials could have good potential in structural applications where it might be in contact with other materials.