Microstructure and mechanical properties of ZrB 2–SiC nanocomposite ceramic

Abstract

A ZrB2–SiC nanocomposite ceramic in which 20 vol.% nanosized SiC powder was introduced into a ZrB2 matrix was fabricated by hot-pressing at 1900 °C for 60 min under a 30 MPa uniaxed load. The composite microstructure showed intragranular nanostructures that were peculiar to this material. Investigation of the mechanical properties revealed a flexural strength of 930 ± 28 MPa and a fracture toughness of 6.5 ± 0.3 MPa m1/2. These improved mechanical properties were strongly dependent on the formation of the unusual intragranular nanostructures.