NU 2006-164
Inventors
Horacio Espinosa*
Francois Barthelat
Short Description
A ceramic composite design that mimics features of Mother of Pearl ("Nacre") in order to increase ceramic toughness
Abstract
Ceramic materials have many attractive engineering qualities such as stiffness, hardness, wear resistance, and resistance to high temperatures. The primary obstacle to a wider use of ceramics in engineering applications is their brittleness. Northwestern researchers have developed a 95% or more of ceramic material, yet is capable of deformation strains in excess of 10%. The design is such that rather than failing at one location, damage is distributed over large volumes of material - improving the ability to resist, and even stop crack propagation. The material is a ceramic composite design that mimics features of Mother of Pearl ('Nacre') in order to increase ceramic toughness. It retains the attractive properties of ceramic composites, but is 5-10 times tougher than the same material in 'bulk' form. This level far surpasses increases reported by prior art that also attempts to mimic Nacre.
Advantages
Softer than bulk ceramic
50% as strong as bulk ceramic but 5 to 10 times tougher than bulk ceramic
Publication
Barthelat F and Espinosa H (2007) An Experimental Investigation of Deformation and Fracture of Nacre-Mother of Pearl. Experimental Mechanics. 47:311-324.
IP Status
Issued US Patent Nos. 8,067,078 and 8,176,705