Preparation and Tribological Properties of Graphene/Carbon Nanotube Reinforced Alumina Ceramic Coating

The carbon nanotube was treated using hybrid-functionalized processing. The aggregates were prepared with a certain proportion of the hybrid-treated carbon nanotube, graphene and alumina and then mixed comprehensively with adhesive agent. The composite ceramic coating was brushed on 304 stainless steel and cured under low temperature. The molecular composition of hybrid-functionalized carbon nanotube was characterized. Meanwhile, the microstructure of the coating and the dispersion of graphene and carbon nanotube were observed. The microhardness, fracture toughness, bonding strength of coating to the metallic substrate and tribological properties were also measured. The hybrid-functionalized carbon nanotube was grafted active groups and was wrapped with surfactant as well. The composite coating was compact with well-distributed graphene and carbon nanotube. Compared to monolithic alumina coating, the graphene/carbon nanotube reinforced alumina ceramic coating had better mechanical properties (hardness, fracture toughness and bonding strength) and tribological properties.