Determination of microstructure and mechanical properties of ceramics bonded tungsten carbide doped with hybrid graphene/SiCw

Abstract

Binderless tungsten carbide possesses superior wear/oxidation/corrosion resistance, high-temperature performance and polishing characteristics in comparison with traditional WC-Co cemented carbide. However, the poor sinterability coupled with intrinsic brittleness has become the twin problem restricting the development of binderless tungsten carbide especially for application specifically at the harsh conditions. Herein, we systemically investigated the effects of hybrid carbide and oxide ceramic binder, SiC whisker and graphene on the densification, microstructure evolution and mechanical properties of tungsten carbide prepared through two-step spark plasma sintering. These results demonstrate that ceramic binder together with SiC whisker performed effectively on improving the densification of WC, while graphene was the optimum reinforcement for WC-SiCw based nanocomposites. Excellent mechanical properties were achieved for SG0.15 samples with a hardness of 23.21 GPa, a flexural strength of 1207.2 MPa as well as a SENB fracture toughness of 10.66 MPa m1/2. This study could provide reference to develop high-performance binderless tungsten carbide matrix composites, further advancing the application of binderless tungsten carbide.

Keywords

• Tungsten carbide
• Ceramic binder
• SiC whisker
• Graphene
• Mechanical properties