Ceramic composites found in nature, such as bone, nacre and sponge spicule, often provide an effective resolution to a well-known conflict between materials’ strength and toughness. This arises, on the one hand, from their high ceramic content that ensures high strength of the material. On the other hand, various pathways are provided for stress dissipation, and thus toughness, due to their intricate hierarchical architectures. Such pathways include crack bridging, crack deflection and delamination in the case of layered structures. Based on these inspiring ideas, we attempted here to create simultaneously strong and tough laminated alumina composite with high ceramic content using high-grade commercial alumina with spin-coated interlayers of ductile polymers (PMMA and PVA). Upon fracture these composites demonstrated exceptional increases in fracture toughness, up to an order of magnitude. Moreover, unlike other synthetic laminates, the composites described in this work became increasingly stiffer and stronger as fracture proceeded, due to an interlocking mechanism similar to one frequently found in natural (biological) composites.
