Study on wear resistance and toughness of calcium ion crosslinked cellulose nanofibers/multi-walled carbon nanotubes/hexagonal boron nitride hybrid reinforced Ni-B composite coatings on N80 steel

This study developed a novel Ni-B/Ca-CNFs/MWCNTs/h-BN coating on N80 steel. The disadvantages of hexagonal boron nitride (h-BN) were improved by creatively combining multi-walled carbon nanotubes (MWCNTs), cellulose nanofibers (CNFs), and calcium ion cross-linking strategies. This led to the creation of Ca-CNFs/ MWCNTs/h-BN hybrids, which were then doped into Ni-B coatings by varying pulse current densities. The results demonstrated that the surface morphology, mechanical properties, and toughness of the composite coating are all influenced by the Ca-CNFs/MWCNTs/h-BN doped at various current densities. Meanwhile, the Ni-B/Ca-CNFs/MWCNTs/h-BN (4 A/dm2) coating has the greatest microhardness (902.42 Hv) and the smallest friction coefficient (0.487) under reciprocating dry sliding friction conditions of Si3N4 friction balls. In addition, the results of nanoindentation and tensile tests show that the elastic modulus of Ni-B/Ca-CNFs/MWCNTs/h-BN (4 A/dm2) composite coating is 194.096 MPa and the tensile elongation is 12.2 %.