Perovskite-type BaTiO3 ceramics containing particulate SiC. Part II Microstructure and mechanical properties

Abstract

Microstructure and mechanical properties of BaTiO3 and BaTiO3-based composites containing nanosized SiC particulates were investigated. Fracture behaviour and fractography were also discussed from the fracture surface observation by scanning electron microscopy and by the controlled surface flaw method. The added SiC particulates were uniformly distributed within the matrix BaTiO3 grains, with some larger particulates located at the BaTiO3 grain boundaries. The microstructure of BaTiO3 was modified by incorporation of the SiC particulate. Mechanical properties, particularly the fracture strength, were remarkably improved by adding the SiC particulate, owing to grain-size reduction and/or crystal structure change by incorporating the SiC. From the fracture surface observations, it was confirmed that the subcritical crack growth phenomenon of BaTiO3 was also improved by the nanosized SiC dispersions.