Preparation and characterization of high hard and high tough ultrafine WC ceramics containing hybrid graphene and SiC nanowire

The aggregation of low-dimensional nanofillers in the host ceramic matrix significantly discounted their reinforcing efficiency. Herein, employing two-dimensional graphene (G) and one-dimensional SiC nanowire (SiCnw), WC-G-SiCnw ceramic composites were prepared through spark plasma sintering. The effects of sintering temperature, soaking time and pressure on the mechanical properties of the WC-based composites were reported. The influence of graphene and SiCnw on the densification, microstructure and mechanical properties of the ceramic composites were investigated. The experimental results demonstrated that excellent mechanical properties were achieved for WC-0.15 wt.% G-0.45 wt.% SiCnw prepared through sintering at 1900 degrees C for 15 min holding time and 60 MPa pressure, with a hardness of 25.6 GPa, a flexural strength of 1499 MPa and a fracture toughness of 11.6 MPa<middle dot>m(1/2). The toughening mechanisms were mainly the combination of G and SiCnw induced crack deflection, bridging and pullout. This study provided a simple toughening method in developing high-performance ceramic composites.