Hierarchical Architectures to Enhance Structural and Functional Properties of Brittle Materials

Abstract

This paper reviews current activities at the Montanuniversität 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.

Interaction between nacre-like CFRP mesolayers and long-fibre interlayers

“…Furthermore, nacre features a hierarchical structure [8,9]. As detailed in Figure 1, in natural shells with a nacre micro-structure, mesolayers of aragonite tiles (∼ 300 µm in thickness) are separated by organic interlayers of protein.…”