Strong, tough, stiff and easy-to-make ceramics that mimic the brick-and-mortar structure of natural nacre - the strong material that makes the outer layer of pearls - are reported in a study published online in Nature Materials. These ceramics, which retain their properties at temperatures up to 600 °C, could be used as structural materials for energy-related and transportation applications where catastrophic failure is not an option.
Ceramics are typically brittle. To improve their toughness, polymers and metals - which can deform without breaking - can be introduced as components. However, these lower the ceramics’ strength, stiffness and high-temperature stability. Inspired by the structure of nacre, Sylvain Deville and colleagues show that bulk ceramics with specific strength and toughness comparable to that of metallic alloys can be made from inherently brittle mineral microplatelets and nanoparticles. The researchers used a method that is based on ice templating, where the growth of ice crystals guides the alignment of the mineral platelets, entrapping the nanoparticles in between them.