Hierarchical Architectures to Enhance Structural and Functional Properties of Brittle Materials

This paper reviews current activities at the Montanuniversitat Leoben on the hierarchical design of flaw-tolerant brittle materials in the fields of layered ceramics, hard coatings, fibre reinforced laminates, and biomimetic functional systems. Different examples of reinforcement mechanisms are presented acting at different length scales. Novel strategies are analyzed that make use of tailored residual stresses, textured microstructures, compositional heterogeneity and spatial variations in properties, fiber arrangement and laminate stacking, or functionalization of hierarchical materials from brittle constituents. Potential implications of hierarchical structures combining different materials science approaches for future engineering designs are discussed.