Mechanical and tribological properties of TiB2-SiC and TiB2 -SiC-GNPs ceramic composites

TiB2-SiC and TiB2-SiC-graphene nanoplatelets (GNPs) composites were prepared using field-assisted sintering technology at 2100 degrees C in argon atmosphere, and the influence of the SiC and different GNPs addition on microstructure development, mechanical and tribological properties has been investigated. Instrumented hardness, bending strength, chevron-notched fracture toughness and ball-on-flat tribological tests were used for the testing and characterization of the composites. The addition of SiC significantly improved the bending strength and elastic modulus with values of 601 MPa and 474 GPa, respectively, but decreased the fracture toughness with a value of 4.8 MPa.m(1/2). The addition of GNPs has a positive effect on fracture toughness and flexural strength but a negative one on the hardness. The increasing amount of both GNPs has a positive influence on wear characteristics of the composites thanks to the described wear mechanisms.