Tough metal-ceramic composites with multifunctional nacre-like architecture

The brick-and-mortar architecture of biological nacre has inspired the development of synthetic composites with enhanced fracture toughness and multiple functionalities. While the use of metals as the mortar phase is an attractive option to maximize fracture toughness of bulk composites, non-mechanical functionalities potentially enabled by the presence of a metal in the structure remain relatively limited and unexplored. Using iron as the mortar phase, we develop and investigate nacre-like composites with high fracture toughness and stiffness combined with unique magnetic, electrical and thermal functionalities. Such metal-ceramic composites are prepared through the sol-gel deposition of iron-based coatings on alumina platelets and the magnetically-driven assembly of the pre-coated platelets into nacre-like architectures, followed by pressure-assisted densification at 1450 degrees C. With the help of state-of-the-art characterization techniques, we show that this processing route leads to lightweight inorganic structures that display outstanding fracture resistance, show noticeable magnetization and are amenable to fast induction heating. Materials with this set of properties might find use in transport, aerospace and robotic applications that require weight minimization combined with magnetic, electrical or thermal functionalities.

Automated summary

The use of iron as the mortar phase in nacre-like composites leads to high fracture toughness and stiffness, as well as unique magnetic, electrical, and thermal functionalities. These metal-ceramic composites demonstrate outstanding fracture resistance, magnetization, and the ability for fast induction heating, making them potentially useful in transport, aerospace, and robotic applications requiring weight minimization combined with specific functionalities.