Alumina/GNPs coating on textured WC/Co substrate: microstructure and tribology

This work aims to provide a method for improving the tribological properties of WC/Co substrates. Laser surface texturing technology was employed to fabricate micro-grooves on the substrate surfaces. Suspension high velocity oxy fuel thermal spraying technique was used to deposit 99 wt-% alumina + 1 wt-% graphene nanoplatelets (GNPs) coating on the substrate surface with micro-grooves. Characterisations such as micromorphology, composition analysis and tribological performance were examined. Results showed that the morphology of the laser prepared micro-groove consisted of two hills and one valley. The grid-textured samples sprayed with alumina/GNPs coating showed the lowest coefficient of friction and wear rate, which was benefited from the larger texture density and the friction reduction of GNPs lubrication film.