A novel biomimetic approach to the design of high-performance ceramic–metal composites

Abstract

The prospect of extending natural biological design to develop new synthetic ceramic–metal composite materials is examined. Using ice-templating of ceramic suspensions and subsequent metal infiltration, we demonstrate that the concept of ordered hierarchical design can be applied to create fine-scale laminated ceramic–metal (bulk) composites that are inexpensive, lightweight and display exceptional damage-tolerance properties. Specifically, Al₂O₃/Al–Si laminates with ceramic contents up to approximately 40 vol% and with lamellae thicknesses down to 10 µm were processed and characterized. These structures achieve an excellent fracture toughness of 40 MPa√m at a tensile strength of approximately 300 MPa. Salient toughening mechanisms are described together with further toughening strategies.